go-sqlite3 v0.7.3.

Bumps [golang.org/x/sync](https://github.com/golang/sync) from 0.2.0 to 0.3.0.
- [Commits](https://github.com/golang/sync/compare/v0.2.0...v0.3.0)

---
updated-dependencies:
- dependency-name: golang.org/x/sync
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/FUNDING.yml

@@ -1 +1 @@
-custom: https://www.paypal.com/donate/buttons/manage/33P59ELZWGMK6
+custom: https://www.paypal.com/donate?hosted_button_id=33P59ELZWGMK6

.github/workflows/go.yml

@@ -5,6 +5,7 @@ on:
     branches: [ "main" ]
   pull_request:
     branches: [ "main" ]
+  workflow_dispatch:
 
 jobs:
   test:
@@ -18,11 +19,28 @@ jobs:
       with:
         lfs: 'true'
 
-    - name: Set up Go
-      uses: actions/setup-go@v3
+    - name: Set up
+      uses: actions/setup-go@v4
       with:
         go-version: stable
-        cache: true
+
+    - name: Format
+      run: gofmt -s -w . && git diff --exit-code
+      if: matrix.os != 'windows-latest'
+
+    - name: Tidy
+      run: go mod tidy && git diff --exit-code
+
+    - name: Download
+      run: go mod download
+
+    # Fixed in go 1.21: https://go.dev/issue/54372
+    # - name: Verify
+    #   run: go mod verify
+
+    - name: Vet
+      run: go vet ./...
+      continue-on-error: true
 
     - name: Build
       run: go build -v ./...
@@ -30,12 +48,15 @@ jobs:
     - name: Test
       run: go test -v ./...
 
-    - name: Test data races
-      run: go test -v -race ./...
-      if: matrix.os == 'ubuntu-latest'
+    - name: Test BSD locks
+      run: go test -v -tags sqlite3_bsd ./...
+      if: matrix.os == 'macos-latest'
 
-    - name: Update coverage report
-      uses: ncruces/go-coverage-report@main
+    - name: Coverage report
+      uses: ncruces/go-coverage-report@v0
+      with:
+        chart: 'true'
+        amend: 'true'
       if: |
         matrix.os == 'ubuntu-latest' &&
         github.event_name == 'push'

README.md

@@ -15,9 +15,17 @@ provides a [`database/sql`](https://pkg.go.dev/database/sql) driver
 ([example usage](https://pkg.go.dev/github.com/ncruces/go-sqlite3/driver#example-package)).
 - Package [`github.com/ncruces/go-sqlite3/embed`](https://pkg.go.dev/github.com/ncruces/go-sqlite3/embed)
 embeds a build of SQLite into your application.
+- Package [`github.com/ncruces/go-sqlite3/vfs`](https://pkg.go.dev/github.com/ncruces/go-sqlite3/vfs)
+wraps the [C SQLite VFS API](https://www.sqlite.org/vfs.html) and provides a pure Go implementation.
+- Package [`github.com/ncruces/go-sqlite3/gormlite`](https://pkg.go.dev/github.com/ncruces/go-sqlite3/gormlite)
+provides a [GORM](https://gorm.io) driver.
 
 ### Caveats
 
+This module replaces the SQLite [OS Interface](https://www.sqlite.org/vfs.html)
+(aka VFS) with a [pure Go](vfs/) implementation.
+This has benefits, but also comes with some drawbacks.
+
 #### Write-Ahead Logging
 
 Because WASM does not support shared memory,
@@ -30,44 +38,47 @@ For non-WAL databases, `NORMAL` locking mode can be activated with
 [`PRAGMA locking_mode=NORMAL`](https://www.sqlite.org/pragma.html#pragma_locking_mode).
 
 Because connection pooling is incompatible with `EXCLUSIVE` locking mode,
-the `database/sql` driver defaults to `NORMAL` locking mode,
-and WAL databases are not supported.
+the `database/sql` driver defaults to `NORMAL` locking mode.
+To open WAL databases, or use `EXCLUSIVE` locking mode,
+disable connection pooling by calling
+[`db.SetMaxOpenConns(1)`](https://pkg.go.dev/database/sql#DB.SetMaxOpenConns).
 
-#### Open File Description Locks
+#### POSIX Advisory Locks
 
-On Unix, this module uses [OFD locks](https://www.gnu.org/software/libc/manual/html_node/Open-File-Description-Locks.html)
+POSIX advisory locks, which SQLite uses, are
+[broken by design](https://www.sqlite.org/src/artifact/90c4fa?ln=1073-1161).
+
+On Linux, macOS and illumos, this module uses
+[OFD locks](https://www.gnu.org/software/libc/manual/html_node/Open-File-Description-Locks.html)
 to synchronize access to database files.
+OFD locks are fully compatible with process-associated POSIX advisory locks.
 
-POSIX advisory locks, which SQLite uses, are [broken by design](https://www.sqlite.org/src/artifact/90c4fa?ln=1073-1161).
-OFD locks are fully compatible with process-associated POSIX advisory locks,
-and are supported on Linux, macOS and illumos.
-As a work around for other Unixes, you can use [`nolock=1`](https://www.sqlite.org/uri.html).
+On BSD Unixes, this module uses
+[BSD locks](https://man.freebsd.org/cgi/man.cgi?query=flock&sektion=2).
+BSD locks may _not_ be compatible with process-associated POSIX advisory locks.
+
+#### Testing
+
+The pure Go VFS is tested by running an unmodified build of SQLite's
+[mptest](https://github.com/sqlite/sqlite/blob/master/mptest/mptest.c)
+on Linux, macOS and Windows.
+Performance is tested by running
+[speedtest1](https://github.com/sqlite/sqlite/blob/master/test/speedtest1.c).
 
 ### Roadmap
 
-- [x] build SQLite using `zig cc --target=wasm32-wasi`
-- [x] `:memory:` databases
-- [x] port [`test_demovfs.c`](https://www.sqlite.org/src/doc/trunk/src/test_demovfs.c) to Go
-  - branch [`wasi`](https://github.com/ncruces/go-sqlite3/tree/wasi) uses `test_demovfs.c` directly
-- [x] design a nice API, enough for simple use cases
-- [x] provide a simple `database/sql` driver
-- [x] file locking, compatible with SQLite on macOS/Linux/Windows
 - [ ] advanced SQLite features
   - [x] nested transactions
   - [x] incremental BLOB I/O
   - [x] online backup
-  - [ ] snapshots
   - [ ] session extension
-  - [ ] resumable bulk update
-  - [ ] shared-cache mode
-  - [ ] unlock-notify
-- [ ] custom SQL functions
 - [ ] custom VFSes
-  - [ ] read-only VFS, wrapping an [`io.ReaderAt`](https://pkg.go.dev/io#ReaderAt)
-  - [ ] in-memory VFS, wrapping a [`bytes.Buffer`](https://pkg.go.dev/bytes#Buffer)
+  - [x] custom VFS API
+  - [x] in-memory VFS
+  - [x] read-only VFS, wrapping an [`io.ReaderAt`](https://pkg.go.dev/io#ReaderAt)
   - [ ] cloud-based VFS, based on [Cloud Backed SQLite](https://sqlite.org/cloudsqlite/doc/trunk/www/index.wiki)
-  - [ ] custom VFS API
-  
+- [ ] custom SQL functions
+
 ### Alternatives
 
 - [`modernc.org/sqlite`](https://pkg.go.dev/modernc.org/sqlite)

backup.go

@@ -1,6 +1,6 @@
 package sqlite3
 
-// Backup is a handle to an open BLOB.
+// Backup is an handle to an ongoing online backup operation.
 //
 // https://www.sqlite.org/c3ref/backup.html
 type Backup struct {
@@ -11,7 +11,7 @@ type Backup struct {
 
 // Backup backs up srcDB on the src connection to the "main" database in dstURI.
 //
-// Backup calls [Conn.Open] to open the SQLite database file dstURI,
+// Backup opens the SQLite database file dstURI,
 // and blocks until the entire backup is complete.
 // Use [Conn.BackupInit] for incremental backup.
 //
@@ -28,12 +28,12 @@ func (src *Conn) Backup(srcDB, dstURI string) error {
 
 // Restore restores dstDB on the dst connection from the "main" database in srcURI.
 //
-// Restore calls [Conn.Open] to open the SQLite database file srcURI,
+// Restore opens the SQLite database file srcURI,
 // and blocks until the entire restore is complete.
 //
 // https://www.sqlite.org/backup.html
 func (dst *Conn) Restore(dstDB, srcURI string) error {
-	src, err := dst.openDB(srcURI, OPEN_READWRITE|OPEN_CREATE|OPEN_URI)
+	src, err := dst.openDB(srcURI, OPEN_READONLY|OPEN_URI)
 	if err != nil {
 		return err
 	}
@@ -48,7 +48,7 @@ func (dst *Conn) Restore(dstDB, srcURI string) error {
 
 // BackupInit initializes a backup operation to copy the content of one database into another.
 //
-// BackupInit calls [Conn.Open] to open the SQLite database file dstURI,
+// BackupInit opens the SQLite database file dstURI,
 // then initializes a backup that copies the contents of srcDB on the src connection
 // to the "main" database in dstURI.
 //
@@ -74,16 +74,16 @@ func (c *Conn) backupInit(dst uint32, dstName string, src uint32, srcName string
 	r := c.call(c.api.backupInit,
 		uint64(dst), uint64(dstPtr),
 		uint64(src), uint64(srcPtr))
-	if r[0] == 0 {
+	if r == 0 {
 		defer c.closeDB(other)
 		r = c.call(c.api.errcode, uint64(dst))
-		return nil, c.module.error(r[0], dst)
+		return nil, c.module.error(r, dst)
 	}
 
 	return &Backup{
 		c:      c,
 		otherc: other,
-		handle: uint32(r[0]),
+		handle: uint32(r),
 	}, nil
 }
 
@@ -100,7 +100,7 @@ func (b *Backup) Close() error {
 	r := b.c.call(b.c.api.backupFinish, uint64(b.handle))
 	b.c.closeDB(b.otherc)
 	b.handle = 0
-	return b.c.error(r[0])
+	return b.c.error(r)
 }
 
 // Step copies up to nPage pages between the source and destination databases.
@@ -109,10 +109,10 @@ func (b *Backup) Close() error {
 // https://www.sqlite.org/c3ref/backup_finish.html#sqlite3backupstep
 func (b *Backup) Step(nPage int) (done bool, err error) {
 	r := b.c.call(b.c.api.backupStep, uint64(b.handle), uint64(nPage))
-	if r[0] == _DONE {
+	if r == _DONE {
 		return true, nil
 	}
-	return false, b.c.error(r[0])
+	return false, b.c.error(r)
 }
 
 // Remaining returns the number of pages still to be backed up
@@ -121,7 +121,7 @@ func (b *Backup) Step(nPage int) (done bool, err error) {
 // https://www.sqlite.org/c3ref/backup_finish.html#sqlite3backupremaining
 func (b *Backup) Remaining() int {
 	r := b.c.call(b.c.api.backupRemaining, uint64(b.handle))
-	return int(r[0])
+	return int(r)
 }
 
 // PageCount returns the total number of pages in the source database
@@ -129,6 +129,6 @@ func (b *Backup) Remaining() int {
 //
 // https://www.sqlite.org/c3ref/backup_finish.html#sqlite3backuppagecount
 func (b *Backup) PageCount() int {
-	r := b.c.call(b.c.api.backupFinish, uint64(b.handle))
-	return int(r[0])
+	r := b.c.call(b.c.api.backupPageCount, uint64(b.handle))
+	return int(r)
 }

blob.go

@@ -1,22 +1,26 @@
 package sqlite3
 
-import "io"
+import (
+	"io"
+
+	"github.com/ncruces/go-sqlite3/internal/util"
+)
 
 // ZeroBlob represents a zero-filled, length n BLOB
 // that can be used as an argument to
 // [database/sql.DB.Exec] and similar methods.
 type ZeroBlob int64
 
-// Blob is a handle to an open BLOB.
+// Blob is an handle to an open BLOB.
 //
 // It implements [io.ReadWriteSeeker] for incremental BLOB I/O.
 //
 // https://www.sqlite.org/c3ref/blob.html
 type Blob struct {
 	c      *Conn
-	handle uint32
 	bytes  int64
 	offset int64
+	handle uint32
 }
 
 var _ io.ReadWriteSeeker = &Blob{}
@@ -25,6 +29,7 @@ var _ io.ReadWriteSeeker = &Blob{}
 //
 // https://www.sqlite.org/c3ref/blob_open.html
 func (c *Conn) OpenBlob(db, table, column string, row int64, write bool) (*Blob, error) {
+	c.checkInterrupt()
 	defer c.arena.reset()
 	blobPtr := c.arena.new(ptrlen)
 	dbPtr := c.arena.string(db)
@@ -40,13 +45,13 @@ func (c *Conn) OpenBlob(db, table, column string, row int64, write bool) (*Blob,
 		uint64(dbPtr), uint64(tablePtr), uint64(columnPtr),
 		uint64(row), flags, uint64(blobPtr))
 
-	if err := c.error(r[0]); err != nil {
+	if err := c.error(r); err != nil {
 		return nil, err
 	}
 
 	blob := Blob{c: c}
-	blob.handle = c.mem.readUint32(blobPtr)
-	blob.bytes = int64(c.call(c.api.blobBytes, uint64(blob.handle))[0])
+	blob.handle = util.ReadUint32(c.mod, blobPtr)
+	blob.bytes = int64(c.call(c.api.blobBytes, uint64(blob.handle)))
 	return &blob, nil
 }
 
@@ -63,7 +68,7 @@ func (b *Blob) Close() error {
 	r := b.c.call(b.c.api.blobClose, uint64(b.handle))
 
 	b.handle = 0
-	return b.c.error(r[0])
+	return b.c.error(r)
 }
 
 // Size returns the size of the BLOB in bytes.
@@ -81,8 +86,40 @@ func (b *Blob) Read(p []byte) (n int, err error) {
 		return 0, io.EOF
 	}
 
-	want := int64(len(p))
 	avail := b.bytes - b.offset
+	want := int64(len(p))
+	if want > avail {
+		want = avail
+	}
+
+	defer b.c.arena.reset()
+	ptr := b.c.arena.new(uint64(want))
+
+	r := b.c.call(b.c.api.blobRead, uint64(b.handle),
+		uint64(ptr), uint64(want), uint64(b.offset))
+	err = b.c.error(r)
+	if err != nil {
+		return 0, err
+	}
+	b.offset += want
+	if b.offset >= b.bytes {
+		err = io.EOF
+	}
+
+	copy(p, util.View(b.c.mod, ptr, uint64(want)))
+	return int(want), err
+}
+
+// WriteTo implements the [io.WriterTo] interface.
+//
+// https://www.sqlite.org/c3ref/blob_read.html
+func (b *Blob) WriteTo(w io.Writer) (n int64, err error) {
+	if b.offset >= b.bytes {
+		return 0, nil
+	}
+
+	avail := b.bytes - b.offset
+	want := int64(65536)
 	if want > avail {
 		want = avail
 	}
@@ -90,37 +127,43 @@ func (b *Blob) Read(p []byte) (n int, err error) {
 	ptr := b.c.new(uint64(want))
 	defer b.c.free(ptr)
 
-	r := b.c.call(b.c.api.blobRead, uint64(b.handle),
-		uint64(ptr), uint64(want), uint64(b.offset))
-	err = b.c.error(r[0])
-	if err != nil {
-		return 0, err
-	}
+	for want > 0 {
+		r := b.c.call(b.c.api.blobRead, uint64(b.handle),
+			uint64(ptr), uint64(want), uint64(b.offset))
+		err = b.c.error(r)
+		if err != nil {
+			return n, err
+		}
 
-	mem := b.c.mem.view(ptr, uint64(want))
-	copy(p, mem)
-	b.offset += want
-	if b.offset >= b.bytes {
-		err = io.EOF
+		mem := util.View(b.c.mod, ptr, uint64(want))
+		m, err := w.Write(mem[:want])
+		b.offset += int64(m)
+		n += int64(m)
+		if err != nil {
+			return n, err
+		}
+		if int64(m) != want {
+			return n, io.ErrShortWrite
+		}
+
+		avail = b.bytes - b.offset
+		if want > avail {
+			want = avail
+		}
 	}
-	return int(want), err
+	return n, nil
 }
 
 // Write implements the [io.Writer] interface.
 //
 // https://www.sqlite.org/c3ref/blob_write.html
 func (b *Blob) Write(p []byte) (n int, err error) {
-	offset := b.offset
-	if offset > b.bytes {
-		offset = b.bytes
-	}
-
-	ptr := b.c.newBytes(p)
-	defer b.c.free(ptr)
+	defer b.c.arena.reset()
+	ptr := b.c.arena.bytes(p)
 
 	r := b.c.call(b.c.api.blobWrite, uint64(b.handle),
-		uint64(ptr), uint64(len(p)), uint64(offset))
-	err = b.c.error(r[0])
+		uint64(ptr), uint64(len(p)), uint64(b.offset))
+	err = b.c.error(r)
 	if err != nil {
 		return 0, err
 	}
@@ -128,11 +171,57 @@ func (b *Blob) Write(p []byte) (n int, err error) {
 	return len(p), nil
 }
 
+// ReadFrom implements the [io.ReaderFrom] interface.
+//
+// https://www.sqlite.org/c3ref/blob_write.html
+func (b *Blob) ReadFrom(r io.Reader) (n int64, err error) {
+	avail := b.bytes - b.offset
+	want := int64(65536)
+	if want > avail {
+		want = avail
+	}
+	if want < 1 {
+		want = 1
+	}
+
+	ptr := b.c.new(uint64(want))
+	defer b.c.free(ptr)
+
+	for {
+		mem := util.View(b.c.mod, ptr, uint64(want))
+		m, err := r.Read(mem[:want])
+		if m > 0 {
+			r := b.c.call(b.c.api.blobWrite, uint64(b.handle),
+				uint64(ptr), uint64(m), uint64(b.offset))
+			err := b.c.error(r)
+			if err != nil {
+				return n, err
+			}
+			b.offset += int64(m)
+			n += int64(m)
+		}
+		if err == io.EOF {
+			return n, nil
+		}
+		if err != nil {
+			return n, err
+		}
+
+		avail = b.bytes - b.offset
+		if want > avail {
+			want = avail
+		}
+		if want < 1 {
+			want = 1
+		}
+	}
+}
+
 // Seek implements the [io.Seeker] interface.
 func (b *Blob) Seek(offset int64, whence int) (int64, error) {
 	switch whence {
 	default:
-		return 0, whenceErr
+		return 0, util.WhenceErr
 	case io.SeekStart:
 		break
 	case io.SeekCurrent:
@@ -141,7 +230,7 @@ func (b *Blob) Seek(offset int64, whence int) (int64, error) {
 		offset += b.bytes
 	}
 	if offset < 0 {
-		return 0, offsetErr
+		return 0, util.OffsetErr
 	}
 	b.offset = offset
 	return offset, nil
@@ -151,8 +240,8 @@ func (b *Blob) Seek(offset int64, whence int) (int64, error) {
 //
 // https://www.sqlite.org/c3ref/blob_reopen.html
 func (b *Blob) Reopen(row int64) error {
-	r := b.c.call(b.c.api.blobReopen, uint64(b.handle), uint64(row))
-	b.bytes = int64(b.c.call(b.c.api.blobBytes, uint64(b.handle))[0])
+	err := b.c.error(b.c.call(b.c.api.blobReopen, uint64(b.handle), uint64(row)))
+	b.bytes = int64(b.c.call(b.c.api.blobBytes, uint64(b.handle)))
 	b.offset = 0
-	return b.c.error(r[0])
+	return err
 }

conn.go

@@ -3,12 +3,15 @@ package sqlite3
 import (
 	"context"
 	"database/sql/driver"
+	"errors"
 	"fmt"
 	"net/url"
 	"runtime"
 	"strings"
 	"sync/atomic"
 	"unsafe"
+
+	"github.com/ncruces/go-sqlite3/internal/util"
 )
 
 // Conn is a database connection handle.
@@ -18,26 +21,31 @@ import (
 type Conn struct {
 	*module
 
-	handle    uint32
-	arena     arena
 	interrupt context.Context
 	waiter    chan struct{}
 	pending   *Stmt
+	arena     arena
+
+	handle uint32
 }
 
-// Open calls [OpenFlags] with [OPEN_READWRITE], [OPEN_CREATE] and [OPEN_URI].
+// Open calls [OpenFlags] with [OPEN_READWRITE], [OPEN_CREATE], [OPEN_URI] and [OPEN_NOFOLLOW].
 func Open(filename string) (*Conn, error) {
-	return newConn(filename, OPEN_READWRITE|OPEN_CREATE|OPEN_URI)
+	return newConn(filename, OPEN_READWRITE|OPEN_CREATE|OPEN_URI|OPEN_NOFOLLOW)
 }
 
 // OpenFlags opens an SQLite database file as specified by the filename argument.
 //
+// If none of the required flags is used, a combination of [OPEN_READWRITE] and [OPEN_CREATE] is used.
 // If a URI filename is used, PRAGMA statements to execute can be specified using "_pragma":
 //
 //	sqlite3.Open("file:demo.db?_pragma=busy_timeout(10000)&_pragma=locking_mode(normal)")
 //
 // https://www.sqlite.org/c3ref/open.html
 func OpenFlags(filename string, flags OpenFlag) (*Conn, error) {
+	if flags&(OPEN_READONLY|OPEN_READWRITE|OPEN_CREATE) == 0 {
+		flags |= OPEN_READWRITE | OPEN_CREATE
+	}
 	return newConn(filename, flags)
 }
 
@@ -50,7 +58,7 @@ func newConn(filename string, flags OpenFlag) (conn *Conn, err error) {
 		if conn == nil {
 			mod.close()
 		} else {
-			runtime.SetFinalizer(conn, finalizer[Conn](3))
+			runtime.SetFinalizer(conn, util.Finalizer[Conn](3))
 		}
 	}()
 
@@ -68,10 +76,11 @@ func (c *Conn) openDB(filename string, flags OpenFlag) (uint32, error) {
 	connPtr := c.arena.new(ptrlen)
 	namePtr := c.arena.string(filename)
 
+	flags |= OPEN_EXRESCODE
 	r := c.call(c.api.open, uint64(namePtr), uint64(connPtr), uint64(flags), 0)
 
-	handle := c.mem.readUint32(connPtr)
-	if err := c.module.error(r[0], handle); err != nil {
+	handle := util.ReadUint32(c.mod, connPtr)
+	if err := c.module.error(r, handle); err != nil {
 		c.closeDB(handle)
 		return 0, err
 	}
@@ -87,19 +96,24 @@ func (c *Conn) openDB(filename string, flags OpenFlag) (uint32, error) {
 			}
 		}
 
+		c.arena.reset()
 		pragmaPtr := c.arena.string(pragmas.String())
 		r := c.call(c.api.exec, uint64(handle), uint64(pragmaPtr), 0, 0, 0)
-		if err := c.module.error(r[0], handle, pragmas.String()); err != nil {
+		if err := c.module.error(r, handle, pragmas.String()); err != nil {
+			if errors.Is(err, ERROR) {
+				err = fmt.Errorf("sqlite3: invalid _pragma: %w", err)
+			}
 			c.closeDB(handle)
-			return 0, fmt.Errorf("sqlite3: invalid _pragma: %w", err)
+			return 0, err
 		}
 	}
+
 	return handle, nil
 }
 
 func (c *Conn) closeDB(handle uint32) {
 	r := c.call(c.api.closeZombie, uint64(handle))
-	if err := c.module.error(r[0], handle); err != nil {
+	if err := c.module.error(r, handle); err != nil {
 		panic(err)
 	}
 }
@@ -119,9 +133,11 @@ func (c *Conn) Close() error {
 	}
 
 	c.SetInterrupt(context.Background())
+	c.pending.Close()
+	c.pending = nil
 
 	r := c.call(c.api.close, uint64(c.handle))
-	if err := c.error(r[0]); err != nil {
+	if err := c.error(r); err != nil {
 		return err
 	}
 
@@ -140,24 +156,7 @@ func (c *Conn) Exec(sql string) error {
 	sqlPtr := c.arena.string(sql)
 
 	r := c.call(c.api.exec, uint64(c.handle), uint64(sqlPtr), 0, 0, 0)
-	return c.error(r[0])
-}
-
-// MustPrepare calls [Conn.Prepare] and panics on error,
-// a nil Stmt, or a non-empty tail.
-func (c *Conn) MustPrepare(sql string) *Stmt {
-	s, tail, err := c.PrepareFlags(sql, 0)
-	if err != nil {
-		panic(err)
-	}
-	if s == nil {
-		panic(emptyErr)
-	}
-	if !emptyStatement(tail) {
-		s.Close()
-		panic(tailErr)
-	}
-	return s
+	return c.error(r)
 }
 
 // Prepare calls [Conn.PrepareFlags] with no flags.
@@ -186,11 +185,11 @@ func (c *Conn) PrepareFlags(sql string, flags PrepareFlag) (stmt *Stmt, tail str
 		uint64(stmtPtr), uint64(tailPtr))
 
 	stmt = &Stmt{c: c}
-	stmt.handle = c.mem.readUint32(stmtPtr)
-	i := c.mem.readUint32(tailPtr)
+	stmt.handle = util.ReadUint32(c.mod, stmtPtr)
+	i := util.ReadUint32(c.mod, tailPtr)
 	tail = sql[i-sqlPtr:]
 
-	if err := c.error(r[0], sql); err != nil {
+	if err := c.error(r, sql); err != nil {
 		return nil, "", err
 	}
 	if stmt.handle == 0 {
@@ -204,7 +203,7 @@ func (c *Conn) PrepareFlags(sql string, flags PrepareFlag) (stmt *Stmt, tail str
 // https://www.sqlite.org/c3ref/get_autocommit.html
 func (c *Conn) GetAutocommit() bool {
 	r := c.call(c.api.autocommit, uint64(c.handle))
-	return r[0] != 0
+	return r != 0
 }
 
 // LastInsertRowID returns the rowid of the most recent successful INSERT
@@ -213,7 +212,7 @@ func (c *Conn) GetAutocommit() bool {
 // https://www.sqlite.org/c3ref/last_insert_rowid.html
 func (c *Conn) LastInsertRowID() int64 {
 	r := c.call(c.api.lastRowid, uint64(c.handle))
-	return int64(r[0])
+	return int64(r)
 }
 
 // Changes returns the number of rows modified, inserted or deleted
@@ -223,7 +222,7 @@ func (c *Conn) LastInsertRowID() int64 {
 // https://www.sqlite.org/c3ref/changes.html
 func (c *Conn) Changes() int64 {
 	r := c.call(c.api.changes, uint64(c.handle))
-	return int64(r[0])
+	return int64(r)
 }
 
 // SetInterrupt interrupts a long-running query when a context is done.
@@ -247,26 +246,23 @@ func (c *Conn) SetInterrupt(ctx context.Context) (old context.Context) {
 		<-c.waiter             // Wait for it to finish.
 		c.waiter = nil
 	}
+	// Reset the pending statement.
+	if c.pending != nil {
+		c.pending.Reset()
+	}
 
 	old = c.interrupt
 	c.interrupt = ctx
 	if ctx == nil || ctx.Done() == nil {
-		// Finalize the uncompleted SQL statement.
-		if c.pending != nil {
-			c.pending.Close()
-			c.pending = nil
-		}
 		return old
 	}
 
 	// Creating an uncompleted SQL statement prevents SQLite from ignoring
 	// an interrupt that comes before any other statements are started.
 	if c.pending == nil {
-		c.pending = c.MustPrepare(`SELECT 1 UNION ALL SELECT 2`)
-		c.pending.Step()
-	} else {
-		c.pending.Reset()
+		c.pending, _, _ = c.Prepare(`SELECT 1 UNION ALL SELECT 2`)
 	}
+	c.pending.Step()
 
 	// Don't create the goroutine if we're already interrupted.
 	// This happens frequently while restoring to a previously interrupted state.
@@ -282,7 +278,8 @@ func (c *Conn) SetInterrupt(ctx context.Context) (old context.Context) {
 			break
 
 		case <-ctx.Done(): // Done was closed.
-			buf := c.mem.view(c.handle+c.api.interrupt, 4)
+			const isInterruptedOffset = 280
+			buf := util.View(c.mod, c.handle+isInterruptedOffset, 4)
 			(*atomic.Uint32)(unsafe.Pointer(&buf[0])).Store(1)
 			// Wait for the next call to SetInterrupt.
 			<-waiter
@@ -298,7 +295,8 @@ func (c *Conn) checkInterrupt() bool {
 	if c.interrupt == nil || c.interrupt.Err() == nil {
 		return false
 	}
-	buf := c.mem.view(c.handle+c.api.interrupt, 4)
+	const isInterruptedOffset = 280
+	buf := util.View(c.mod, c.handle+isInterruptedOffset, 4)
 	(*atomic.Uint32)(unsafe.Pointer(&buf[0])).Store(1)
 	return true
 }
@@ -306,15 +304,18 @@ func (c *Conn) checkInterrupt() bool {
 // Pragma executes a PRAGMA statement and returns any results.
 //
 // https://www.sqlite.org/pragma.html
-func (c *Conn) Pragma(str string) []string {
-	stmt := c.MustPrepare(`PRAGMA ` + str)
+func (c *Conn) Pragma(str string) ([]string, error) {
+	stmt, _, err := c.Prepare(`PRAGMA ` + str)
+	if err != nil {
+		return nil, err
+	}
 	defer stmt.Close()
 
 	var pragmas []string
 	for stmt.Step() {
 		pragmas = append(pragmas, stmt.ColumnText(0))
 	}
-	return pragmas
+	return pragmas, stmt.Close()
 }
 
 func (c *Conn) error(rc uint64, sql ...string) error {
@@ -324,15 +325,21 @@ func (c *Conn) error(rc uint64, sql ...string) error {
 // DriverConn is implemented by the SQLite [database/sql] driver connection.
 //
 // It can be used to access advanced SQLite features like
-// [savepoints] and [incremental BLOB I/O].
+// [savepoints], [online backup] and [incremental BLOB I/O].
 //
 // [savepoints]: https://www.sqlite.org/lang_savepoint.html
+// [online backup]: https://www.sqlite.org/backup.html
 // [incremental BLOB I/O]: https://www.sqlite.org/c3ref/blob_open.html
 type DriverConn interface {
+	driver.Conn
 	driver.ConnBeginTx
 	driver.ExecerContext
 	driver.ConnPrepareContext
 
-	Savepoint() (release func(*error))
+	SetInterrupt(ctx context.Context) (old context.Context)
+
+	Savepoint() Savepoint
+	Backup(srcDB, dstURI string) error
+	Restore(dstDB, srcURI string) error
 	OpenBlob(db, table, column string, row int64, write bool) (*Blob, error)
 }

const.go

@@ -9,8 +9,7 @@ const (
 
 	_UTF8 = 1
 
-	_MAX_STRING   = 512 // Used for short strings: names, error messages…
-	_MAX_PATHNAME = 512
+	_MAX_STRING = 512 // Used for short strings: names, error messages…
 
 	_MAX_ALLOCATION_SIZE = 0x7ffffeff
 
@@ -133,46 +132,28 @@ const (
 	CONSTRAINT_DATATYPE     ExtendedErrorCode = xErrorCode(CONSTRAINT) | (12 << 8)
 	NOTICE_RECOVER_WAL      ExtendedErrorCode = xErrorCode(NOTICE) | (1 << 8)
 	NOTICE_RECOVER_ROLLBACK ExtendedErrorCode = xErrorCode(NOTICE) | (2 << 8)
+	NOTICE_RBU              ExtendedErrorCode = xErrorCode(NOTICE) | (3 << 8)
 	WARNING_AUTOINDEX       ExtendedErrorCode = xErrorCode(WARNING) | (1 << 8)
 	AUTH_USER               ExtendedErrorCode = xErrorCode(AUTH) | (1 << 8)
 )
 
-// OpenFlag is a flag for a file open operation.
+// OpenFlag is a flag for the [OpenFlags] function.
 //
 // https://www.sqlite.org/c3ref/c_open_autoproxy.html
 type OpenFlag uint32
 
 const (
-	OPEN_READONLY      OpenFlag = 0x00000001 /* Ok for sqlite3_open_v2() */
-	OPEN_READWRITE     OpenFlag = 0x00000002 /* Ok for sqlite3_open_v2() */
-	OPEN_CREATE        OpenFlag = 0x00000004 /* Ok for sqlite3_open_v2() */
-	OPEN_DELETEONCLOSE OpenFlag = 0x00000008 /* VFS only */
-	OPEN_EXCLUSIVE     OpenFlag = 0x00000010 /* VFS only */
-	OPEN_AUTOPROXY     OpenFlag = 0x00000020 /* VFS only */
-	OPEN_URI           OpenFlag = 0x00000040 /* Ok for sqlite3_open_v2() */
-	OPEN_MEMORY        OpenFlag = 0x00000080 /* Ok for sqlite3_open_v2() */
-	OPEN_MAIN_DB       OpenFlag = 0x00000100 /* VFS only */
-	OPEN_TEMP_DB       OpenFlag = 0x00000200 /* VFS only */
-	OPEN_TRANSIENT_DB  OpenFlag = 0x00000400 /* VFS only */
-	OPEN_MAIN_JOURNAL  OpenFlag = 0x00000800 /* VFS only */
-	OPEN_TEMP_JOURNAL  OpenFlag = 0x00001000 /* VFS only */
-	OPEN_SUBJOURNAL    OpenFlag = 0x00002000 /* VFS only */
-	OPEN_SUPER_JOURNAL OpenFlag = 0x00004000 /* VFS only */
-	OPEN_NOMUTEX       OpenFlag = 0x00008000 /* Ok for sqlite3_open_v2() */
-	OPEN_FULLMUTEX     OpenFlag = 0x00010000 /* Ok for sqlite3_open_v2() */
-	OPEN_SHAREDCACHE   OpenFlag = 0x00020000 /* Ok for sqlite3_open_v2() */
-	OPEN_PRIVATECACHE  OpenFlag = 0x00040000 /* Ok for sqlite3_open_v2() */
-	OPEN_WAL           OpenFlag = 0x00080000 /* VFS only */
-	OPEN_NOFOLLOW      OpenFlag = 0x01000000 /* Ok for sqlite3_open_v2() */
-	OPEN_EXRESCODE     OpenFlag = 0x02000000 /* Extended result codes */
-)
-
-type _AccessFlag uint32
-
-const (
-	_ACCESS_EXISTS    _AccessFlag = 0
-	_ACCESS_READWRITE _AccessFlag = 1 /* Used by PRAGMA temp_store_directory */
-	_ACCESS_READ      _AccessFlag = 2 /* Unused */
+	OPEN_READONLY     OpenFlag = 0x00000001 /* Ok for sqlite3_open_v2() */
+	OPEN_READWRITE    OpenFlag = 0x00000002 /* Ok for sqlite3_open_v2() */
+	OPEN_CREATE       OpenFlag = 0x00000004 /* Ok for sqlite3_open_v2() */
+	OPEN_URI          OpenFlag = 0x00000040 /* Ok for sqlite3_open_v2() */
+	OPEN_MEMORY       OpenFlag = 0x00000080 /* Ok for sqlite3_open_v2() */
+	OPEN_NOMUTEX      OpenFlag = 0x00008000 /* Ok for sqlite3_open_v2() */
+	OPEN_FULLMUTEX    OpenFlag = 0x00010000 /* Ok for sqlite3_open_v2() */
+	OPEN_SHAREDCACHE  OpenFlag = 0x00020000 /* Ok for sqlite3_open_v2() */
+	OPEN_PRIVATECACHE OpenFlag = 0x00040000 /* Ok for sqlite3_open_v2() */
+	OPEN_NOFOLLOW     OpenFlag = 0x01000000 /* Ok for sqlite3_open_v2() */
+	OPEN_EXRESCODE    OpenFlag = 0x02000000 /* Extended result codes */
 )
 
 // PrepareFlag is a flag that can be passed to [Conn.PrepareFlags].

driver/driver.go

@@ -16,9 +16,12 @@
 //
 //	sql.Open("sqlite3", "file:demo.db?_pragma=busy_timeout(10000)&_pragma=locking_mode(normal)")
 //
-// If no PRAGMAs are specifed, a busy timeout of 1 minute
+// If no PRAGMAs are specified, a busy timeout of 1 minute
 // and normal locking mode are used.
 //
+// Order matters:
+// busy timeout and locking mode should be the first PRAGMAs set, in that order.
+//
 // [URI]: https://www.sqlite.org/uri.html
 // [PRAGMA]: https://www.sqlite.org/pragma.html
 // [TRANSACTION]: https://www.sqlite.org/lang_transaction.html#deferred_immediate_and_exclusive_transactions
@@ -35,6 +38,7 @@ import (
 	"time"
 
 	"github.com/ncruces/go-sqlite3"
+	"github.com/ncruces/go-sqlite3/internal/util"
 )
 
 func init() {
@@ -44,12 +48,13 @@ func init() {
 type sqlite struct{}
 
 func (sqlite) Open(name string) (_ driver.Conn, err error) {
-	c, err := sqlite3.OpenFlags(name, sqlite3.OPEN_READWRITE|sqlite3.OPEN_CREATE|sqlite3.OPEN_URI|sqlite3.OPEN_EXRESCODE)
+	var c conn
+	c.Conn, err = sqlite3.Open(name)
 	if err != nil {
 		return nil, err
 	}
 
-	var txBegin string
+	c.txBegin = "BEGIN"
 	var pragmas []string
 	if strings.HasPrefix(name, "file:") {
 		if _, after, ok := strings.Cut(name, "?"); ok {
@@ -57,9 +62,9 @@ func (sqlite) Open(name string) (_ driver.Conn, err error) {
 
 			switch s := query.Get("_txlock"); s {
 			case "":
-				txBegin = "BEGIN"
+				c.txBegin = "BEGIN"
 			case "deferred", "immediate", "exclusive":
-				txBegin = "BEGIN " + s
+				c.txBegin = "BEGIN " + s
 			default:
 				c.Close()
 				return nil, fmt.Errorf("sqlite3: invalid _txlock: %s", s)
@@ -69,7 +74,7 @@ func (sqlite) Open(name string) (_ driver.Conn, err error) {
 		}
 	}
 	if len(pragmas) == 0 {
-		err := c.Exec(`
+		err := c.Conn.Exec(`
 			PRAGMA busy_timeout=60000;
 			PRAGMA locking_mode=normal;
 		`)
@@ -77,81 +82,116 @@ func (sqlite) Open(name string) (_ driver.Conn, err error) {
 			c.Close()
 			return nil, err
 		}
+		c.reusable = true
+	} else {
+		s, _, err := c.Conn.Prepare(`
+			SELECT * FROM
+				PRAGMA_locking_mode,
+				PRAGMA_query_only;
+		`)
+		if err != nil {
+			c.Close()
+			return nil, err
+		}
+		if s.Step() {
+			c.reusable = s.ColumnText(0) == "normal"
+			c.readOnly = s.ColumnRawText(1)[0] // 0 or 1
+		}
+		err = s.Close()
+		if err != nil {
+			c.Close()
+			return nil, err
+		}
 	}
-
-	return conn{
-		conn:    c,
-		txBegin: txBegin,
-	}, nil
+	return &c, nil
 }
 
 type conn struct {
-	conn     *sqlite3.Conn
-	txBegin  string
-	txCommit string
+	*sqlite3.Conn
+	txBegin    string
+	txCommit   string
+	txRollback string
+	reusable   bool
+	readOnly   byte
 }
 
 var (
 	// Ensure these interfaces are implemented:
-	_ driver.ExecerContext = conn{}
-	_ driver.ConnBeginTx   = conn{}
-	_ sqlite3.DriverConn   = conn{}
+	_ driver.ExecerContext = &conn{}
+	_ driver.ConnBeginTx   = &conn{}
+	_ driver.Validator     = &conn{}
+	_ sqlite3.DriverConn   = &conn{}
 )
 
-func (c conn) Close() error {
-	return c.conn.Close()
+func (c *conn) IsValid() bool {
+	return c.reusable
 }
 
-func (c conn) Begin() (driver.Tx, error) {
+func (c *conn) Begin() (driver.Tx, error) {
 	return c.BeginTx(context.Background(), driver.TxOptions{})
 }
 
-func (c conn) BeginTx(ctx context.Context, opts driver.TxOptions) (driver.Tx, error) {
-	switch opts.Isolation {
-	default:
-		return nil, isolationErr
-	case driver.IsolationLevel(sql.LevelDefault):
-	case driver.IsolationLevel(sql.LevelSerializable):
-	}
-
+func (c *conn) BeginTx(ctx context.Context, opts driver.TxOptions) (driver.Tx, error) {
 	txBegin := c.txBegin
 	c.txCommit = `COMMIT`
+	c.txRollback = `ROLLBACK`
+
 	if opts.ReadOnly {
-		c.txCommit = `
-			ROLLBACK;
-			PRAGMA query_only=` + c.conn.Pragma("query_only")[0]
 		txBegin = `
 			BEGIN deferred;
 			PRAGMA query_only=on`
+		c.txCommit = `
+			ROLLBACK;
+			PRAGMA query_only=` + string(c.readOnly)
+		c.txRollback = c.txCommit
 	}
 
-	err := c.conn.Exec(txBegin)
+	switch opts.Isolation {
+	default:
+		return nil, util.IsolationErr
+	case
+		driver.IsolationLevel(sql.LevelDefault),
+		driver.IsolationLevel(sql.LevelSerializable):
+		break
+	}
+
+	old := c.Conn.SetInterrupt(ctx)
+	defer c.Conn.SetInterrupt(old)
+
+	err := c.Conn.Exec(txBegin)
 	if err != nil {
 		return nil, err
 	}
 	return c, nil
 }
 
-func (c conn) Commit() error {
-	err := c.conn.Exec(c.txCommit)
-	if err != nil {
+func (c *conn) Commit() error {
+	err := c.Conn.Exec(c.txCommit)
+	if err != nil && !c.GetAutocommit() {
 		c.Rollback()
 	}
 	return err
 }
 
-func (c conn) Rollback() error {
-	return c.conn.Exec(`ROLLBACK`)
+func (c *conn) Rollback() error {
+	return c.Conn.Exec(c.txRollback)
 }
 
-func (c conn) Prepare(query string) (driver.Stmt, error) {
-	s, tail, err := c.conn.Prepare(query)
+func (c *conn) Prepare(query string) (driver.Stmt, error) {
+	return c.PrepareContext(context.Background(), query)
+}
+
+func (c *conn) PrepareContext(ctx context.Context, query string) (driver.Stmt, error) {
+	old := c.Conn.SetInterrupt(ctx)
+	defer c.Conn.SetInterrupt(old)
+
+	s, tail, err := c.Conn.Prepare(query)
 	if err != nil {
 		return nil, err
 	}
 	if tail != "" {
 		// Check if the tail contains any SQL.
-		st, _, err := c.conn.Prepare(tail)
+		st, _, err := c.Conn.Prepare(tail)
 		if err != nil {
 			s.Close()
 			return nil, err
@@ -159,64 +199,49 @@ func (c conn) Prepare(query string) (driver.Stmt, error) {
 		if st != nil {
 			s.Close()
 			st.Close()
-			return nil, tailErr
+			return nil, util.TailErr
 		}
 	}
-	return stmt{s, c.conn}, nil
+	return &stmt{s, c.Conn}, nil
 }
 
-func (c conn) PrepareContext(_ context.Context, query string) (driver.Stmt, error) {
-	return c.Prepare(query)
-}
-
-func (c conn) ExecContext(ctx context.Context, query string, args []driver.NamedValue) (driver.Result, error) {
+func (c *conn) ExecContext(ctx context.Context, query string, args []driver.NamedValue) (driver.Result, error) {
 	if len(args) != 0 {
 		// Slow path.
 		return nil, driver.ErrSkip
 	}
 
-	old := c.conn.SetInterrupt(ctx)
-	defer c.conn.SetInterrupt(old)
+	old := c.Conn.SetInterrupt(ctx)
+	defer c.Conn.SetInterrupt(old)
 
-	err := c.conn.Exec(query)
+	err := c.Conn.Exec(query)
 	if err != nil {
 		return nil, err
 	}
 
-	return result{
-		c.conn.LastInsertRowID(),
-		c.conn.Changes(),
-	}, nil
-}
-
-func (c conn) Savepoint() (release func(*error)) {
-	return c.conn.Savepoint()
-}
-
-func (c conn) OpenBlob(db, table, column string, row int64, write bool) (*sqlite3.Blob, error) {
-	return c.conn.OpenBlob(db, table, column, row, write)
+	return newResult(c.Conn), nil
 }
 
 type stmt struct {
-	stmt *sqlite3.Stmt
-	conn *sqlite3.Conn
+	Stmt *sqlite3.Stmt
+	Conn *sqlite3.Conn
 }
 
 var (
 	// Ensure these interfaces are implemented:
-	_ driver.StmtExecContext   = stmt{}
-	_ driver.StmtQueryContext  = stmt{}
-	_ driver.NamedValueChecker = stmt{}
+	_ driver.StmtExecContext   = &stmt{}
+	_ driver.StmtQueryContext  = &stmt{}
+	_ driver.NamedValueChecker = &stmt{}
 )
 
-func (s stmt) Close() error {
-	return s.stmt.Close()
+func (s *stmt) Close() error {
+	return s.Stmt.Close()
 }
 
-func (s stmt) NumInput() int {
-	n := s.stmt.BindCount()
+func (s *stmt) NumInput() int {
+	n := s.Stmt.BindCount()
 	for i := 1; i <= n; i++ {
-		if s.stmt.BindName(i) != "" {
+		if s.Stmt.BindName(i) != "" {
 			return -1
 		}
 	}
@@ -224,16 +249,16 @@ func (s stmt) NumInput() int {
 }
 
 // Deprecated: use ExecContext instead.
-func (s stmt) Exec(args []driver.Value) (driver.Result, error) {
+func (s *stmt) Exec(args []driver.Value) (driver.Result, error) {
 	return s.ExecContext(context.Background(), namedValues(args))
 }
 
 // Deprecated: use QueryContext instead.
-func (s stmt) Query(args []driver.Value) (driver.Rows, error) {
+func (s *stmt) Query(args []driver.Value) (driver.Rows, error) {
 	return s.QueryContext(context.Background(), namedValues(args))
 }
 
-func (s stmt) ExecContext(ctx context.Context, args []driver.NamedValue) (driver.Result, error) {
+func (s *stmt) ExecContext(ctx context.Context, args []driver.NamedValue) (driver.Result, error) {
 	// Use QueryContext to setup bindings.
 	// No need to close rows: that simply resets the statement, exec does the same.
 	_, err := s.QueryContext(ctx, args)
@@ -241,19 +266,16 @@ func (s stmt) ExecContext(ctx context.Context, args []driver.NamedValue) (driver
 		return nil, err
 	}
 
-	err = s.stmt.Exec()
+	err = s.Stmt.Exec()
 	if err != nil {
 		return nil, err
 	}
 
-	return result{
-		int64(s.conn.LastInsertRowID()),
-		int64(s.conn.Changes()),
-	}, nil
+	return newResult(s.Conn), nil
 }
 
-func (s stmt) QueryContext(ctx context.Context, args []driver.NamedValue) (driver.Rows, error) {
-	err := s.stmt.ClearBindings()
+func (s *stmt) QueryContext(ctx context.Context, args []driver.NamedValue) (driver.Rows, error) {
+	err := s.Stmt.ClearBindings()
 	if err != nil {
 		return nil, err
 	}
@@ -265,7 +287,7 @@ func (s stmt) QueryContext(ctx context.Context, args []driver.NamedValue) (drive
 			ids = append(ids, arg.Ordinal)
 		} else {
 			for _, prefix := range []string{":", "@", "$"} {
-				if id := s.stmt.BindIndex(prefix + arg.Name); id != 0 {
+				if id := s.Stmt.BindIndex(prefix + arg.Name); id != 0 {
 					ids = append(ids, id)
 				}
 			}
@@ -274,25 +296,25 @@ func (s stmt) QueryContext(ctx context.Context, args []driver.NamedValue) (drive
 		for _, id := range ids {
 			switch a := arg.Value.(type) {
 			case bool:
-				err = s.stmt.BindBool(id, a)
+				err = s.Stmt.BindBool(id, a)
 			case int:
-				err = s.stmt.BindInt(id, a)
+				err = s.Stmt.BindInt(id, a)
 			case int64:
-				err = s.stmt.BindInt64(id, a)
+				err = s.Stmt.BindInt64(id, a)
 			case float64:
-				err = s.stmt.BindFloat(id, a)
+				err = s.Stmt.BindFloat(id, a)
 			case string:
-				err = s.stmt.BindText(id, a)
+				err = s.Stmt.BindText(id, a)
 			case []byte:
-				err = s.stmt.BindBlob(id, a)
+				err = s.Stmt.BindBlob(id, a)
 			case sqlite3.ZeroBlob:
-				err = s.stmt.BindZeroBlob(id, int64(a))
+				err = s.Stmt.BindZeroBlob(id, int64(a))
 			case time.Time:
-				err = s.stmt.BindText(id, a.Format(time.RFC3339Nano))
+				err = s.Stmt.BindTime(id, a, sqlite3.TimeFormatDefault)
 			case nil:
-				err = s.stmt.BindNull(id)
+				err = s.Stmt.BindNull(id)
 			default:
-				panic(assertErr)
+				panic(util.AssertErr())
 			}
 		}
 		if err != nil {
@@ -300,10 +322,10 @@ func (s stmt) QueryContext(ctx context.Context, args []driver.NamedValue) (drive
 		}
 	}
 
-	return rows{ctx, s.stmt, s.conn}, nil
+	return &rows{ctx, s.Stmt, s.Conn}, nil
 }
 
-func (s stmt) CheckNamedValue(arg *driver.NamedValue) error {
+func (s *stmt) CheckNamedValue(arg *driver.NamedValue) error {
 	switch arg.Value.(type) {
 	case bool, int, int64, float64, string, []byte,
 		sqlite3.ZeroBlob, time.Time, nil:
@@ -313,6 +335,17 @@ func (s stmt) CheckNamedValue(arg *driver.NamedValue) error {
 	}
 }
 
+func newResult(c *sqlite3.Conn) driver.Result {
+	rows := c.Changes()
+	if rows != 0 {
+		id := c.LastInsertRowID()
+		if id != 0 {
+			return result{id, rows}
+		}
+	}
+	return resultRowsAffected(rows)
+}
+
 type result struct{ lastInsertId, rowsAffected int64 }
 
 func (r result) LastInsertId() (int64, error) {
@@ -323,47 +356,56 @@ func (r result) RowsAffected() (int64, error) {
 	return r.rowsAffected, nil
 }
 
+type resultRowsAffected int64
+
+func (r resultRowsAffected) LastInsertId() (int64, error) {
+	return 0, nil
+}
+
+func (r resultRowsAffected) RowsAffected() (int64, error) {
+	return int64(r), nil
+}
+
 type rows struct {
 	ctx  context.Context
-	stmt *sqlite3.Stmt
-	conn *sqlite3.Conn
+	Stmt *sqlite3.Stmt
+	Conn *sqlite3.Conn
 }
 
-func (r rows) Close() error {
-	return r.stmt.Reset()
+func (r *rows) Close() error {
+	return r.Stmt.Reset()
 }
 
-func (r rows) Columns() []string {
-	count := r.stmt.ColumnCount()
+func (r *rows) Columns() []string {
+	count := r.Stmt.ColumnCount()
 	columns := make([]string, count)
 	for i := range columns {
-		columns[i] = r.stmt.ColumnName(i)
+		columns[i] = r.Stmt.ColumnName(i)
 	}
 	return columns
 }
 
-func (r rows) Next(dest []driver.Value) error {
-	old := r.conn.SetInterrupt(r.ctx)
-	defer r.conn.SetInterrupt(old)
+func (r *rows) Next(dest []driver.Value) error {
+	old := r.Conn.SetInterrupt(r.ctx)
+	defer r.Conn.SetInterrupt(old)
 
-	if !r.stmt.Step() {
-		if err := r.stmt.Err(); err != nil {
+	if !r.Stmt.Step() {
+		if err := r.Stmt.Err(); err != nil {
 			return err
 		}
 		return io.EOF
 	}
 
 	for i := range dest {
-		switch r.stmt.ColumnType(i) {
+		switch r.Stmt.ColumnType(i) {
 		case sqlite3.INTEGER:
-			dest[i] = r.stmt.ColumnInt64(i)
+			dest[i] = r.Stmt.ColumnInt64(i)
 		case sqlite3.FLOAT:
-			dest[i] = r.stmt.ColumnFloat(i)
-		case sqlite3.TEXT:
-			dest[i] = maybeTime(r.stmt.ColumnText(i))
+			dest[i] = r.Stmt.ColumnFloat(i)
 		case sqlite3.BLOB:
-			buf, _ := dest[i].([]byte)
-			dest[i] = r.stmt.ColumnBlob(i, buf)
+			dest[i] = r.Stmt.ColumnRawBlob(i)
+		case sqlite3.TEXT:
+			dest[i] = stringOrTime(r.Stmt.ColumnRawText(i))
 		case sqlite3.NULL:
 			if buf, ok := dest[i].([]byte); ok {
 				dest[i] = buf[0:0]
@@ -371,9 +413,9 @@ func (r rows) Next(dest []driver.Value) error {
 				dest[i] = nil
 			}
 		default:
-			panic(assertErr)
+			panic(util.AssertErr())
 		}
 	}
 
-	return r.stmt.Err()
+	return r.Stmt.Err()
 }

driver/driver_test.go

@@ -1,4 +1,3 @@
-// Package driver provides a database/sql driver for SQLite.
 package driver
 
 import (
@@ -12,6 +11,7 @@ import (
 	"time"
 
 	"github.com/ncruces/go-sqlite3"
+	"github.com/ncruces/go-sqlite3/internal/util"
 )
 
 func Test_Open_dir(t *testing.T) {
@@ -134,14 +134,16 @@ func Test_BeginTx(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	db, err := sql.Open("sqlite3", filepath.Join(t.TempDir(), "test.db"))
+	db, err := sql.Open("sqlite3", "file:"+
+		filepath.ToSlash(filepath.Join(t.TempDir(), "test.db"))+
+		"?_txlock=exclusive&_pragma=busy_timeout(0)")
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer db.Close()
 
 	_, err = db.BeginTx(ctx, &sql.TxOptions{Isolation: sql.LevelReadCommitted})
-	if err.Error() != string(isolationErr) {
+	if err.Error() != string(util.IsolationErr) {
 		t.Error("want isolationErr")
 	}
 
@@ -219,7 +221,7 @@ func Test_Prepare(t *testing.T) {
 	}
 
 	_, err = db.Prepare(`SELECT 1; SELECT 2`)
-	if err.Error() != string(tailErr) {
+	if err.Error() != string(util.TailErr) {
 		t.Error("want tailErr")
 	}
 }
@@ -297,7 +299,7 @@ func Test_QueryRow_blob_null(t *testing.T) {
 
 	want := [][]byte{nil, {0xca, 0xfe}, {0xba, 0xbe}, nil}
 	for i := 0; rows.Next(); i++ {
-		var buf []byte
+		var buf sql.RawBytes
 		err = rows.Scan(&buf)
 		if err != nil {
 			t.Fatal(err)

driver/error.go

@@ -1,11 +0,0 @@
-package driver
-
-type errorString string
-
-func (e errorString) Error() string { return string(e) }
-
-const (
-	assertErr    = errorString("sqlite3: assertion failed")
-	tailErr      = errorString("sqlite3: multiple statements")
-	isolationErr = errorString("sqlite3: unsupported isolation level")
-)

driver/time.go

@@ -9,23 +9,23 @@ import (
 // if it roundtrips back to the same string.
 // This way times can be persisted to, and recovered from, the database,
 // but if a string is needed, [database/sql] will recover the same string.
-func maybeTime(text string) driver.Value {
+func stringOrTime(text []byte) driver.Value {
 	// Weed out (some) values that can't possibly be
 	// [time.RFC3339Nano] timestamps.
 	if len(text) < len("2006-01-02T15:04:05Z") {
-		return text
+		return string(text)
 	}
 	if len(text) > len(time.RFC3339Nano) {
-		return text
+		return string(text)
 	}
 	if text[4] != '-' || text[10] != 'T' || text[16] != ':' {
-		return text
+		return string(text)
 	}
 
 	// Slow path.
-	date, err := time.Parse(time.RFC3339Nano, text)
-	if err == nil && date.Format(time.RFC3339Nano) == text {
+	date, err := time.Parse(time.RFC3339Nano, string(text))
+	if err == nil && date.Format(time.RFC3339Nano) == string(text) {
 		return date
 	}
-	return text
+	return string(text)
 }

driver/time_test.go

@@ -6,7 +6,7 @@ import (
 )
 
 // This checks that any string can be recovered as the same string.
-func Fuzz_maybeTime_1(f *testing.F) {
+func Fuzz_stringOrTime_1(f *testing.F) {
 	f.Add("")
 	f.Add(" ")
 	f.Add("SQLite")
@@ -22,7 +22,7 @@ func Fuzz_maybeTime_1(f *testing.F) {
 	f.Add("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.")
 
 	f.Fuzz(func(t *testing.T, str string) {
-		value := maybeTime(str)
+		value := stringOrTime([]byte(str))
 
 		switch v := value.(type) {
 		case time.Time:
@@ -48,7 +48,7 @@ func Fuzz_maybeTime_1(f *testing.F) {
 
 // This checks that any [time.Time] can be recovered as a [time.Time],
 // with nanosecond accuracy, and preserving any timezone offset.
-func Fuzz_maybeTime_2(f *testing.F) {
+func Fuzz_stringOrTime_2(f *testing.F) {
 	f.Add(0, 0)
 	f.Add(0, 1)
 	f.Add(0, -1)
@@ -59,7 +59,7 @@ func Fuzz_maybeTime_2(f *testing.F) {
 	f.Add(-763421161058, 222_222_222) // twosday, year 22222BC
 
 	checkTime := func(t *testing.T, date time.Time) {
-		value := maybeTime(date.Format(time.RFC3339Nano))
+		value := stringOrTime([]byte(date.Format(time.RFC3339Nano)))
 
 		switch v := value.(type) {
 		case time.Time:

driver_test.go

@@ -48,7 +48,8 @@ func ExampleDriverConn() {
 
 	err = conn.Raw(func(driverConn any) error {
 		conn := driverConn.(sqlite3.DriverConn)
-		defer conn.Savepoint()(&err)
+		savept := conn.Savepoint()
+		defer savept.Release(&err)
 
 		blob, err := conn.OpenBlob("main", "test", "col", id, true)
 		if err != nil {

embed/README.md

@@ -0,0 +1,24 @@
+# Embeddable WASM build of SQLite
+
+This folder includes an embeddable WASM build of SQLite 3.42.0 for use with
+[`github.com/ncruces/go-sqlite3`](https://pkg.go.dev/github.com/ncruces/go-sqlite3).
+
+The following optional features are compiled in:
+- [math functions](https://www.sqlite.org/lang_mathfunc.html)
+- [FTS3/4](https://www.sqlite.org/fts3.html)/[5](https://www.sqlite.org/fts5.html)
+- [JSON](https://www.sqlite.org/json1.html)
+- [R*Tree](https://www.sqlite.org/rtree.html)
+- [GeoPoly](https://www.sqlite.org/geopoly.html)
+- [base64](https://github.com/sqlite/sqlite/blob/master/ext/misc/base64.c)
+- [decimal](https://github.com/sqlite/sqlite/blob/master/ext/misc/decimal.c)
+- [regexp](https://github.com/sqlite/sqlite/blob/master/ext/misc/regexp.c)
+- [series](https://github.com/sqlite/sqlite/blob/master/ext/misc/series.c)
+- [uint](https://github.com/sqlite/sqlite/blob/master/ext/misc/uint.c)
+- [uuid](https://github.com/sqlite/sqlite/blob/master/ext/misc/uuid.c)
+- [time](../sqlite3/time.c)
+
+See the [configuration options](../sqlite3/sqlite_cfg.h),
+and [patches](../sqlite3) applied.
+
+Built using [`wasi-sdk`](https://github.com/WebAssembly/wasi-sdk),
+and [`binaryen`](https://github.com/WebAssembly/binaryen).

embed/build.sh

@@ -1,16 +1,27 @@
 #!/usr/bin/env bash
-set -eo pipefail
+set -euo pipefail
 
 cd -P -- "$(dirname -- "$0")"
 
-# download SQLite
-../sqlite3/download.sh
+ROOT=../
+BINARYEN="$ROOT/tools/binaryen-version_113/bin"
+WASI_SDK="$ROOT/tools/wasi-sdk-20.0/bin"
 
-# build SQLite
-zig cc --target=wasm32-wasi -flto -g0 -Os \
-  -o sqlite3.wasm ../sqlite3/amalg.c \
+"$WASI_SDK/clang" --target=wasm32-wasi -flto -g0 -O2 \
+	-o sqlite3.wasm "$ROOT/sqlite3/main.c" \
+	-I"$ROOT/sqlite3" \
+	-mexec-model=reactor \
 	-mmutable-globals \
 	-mbulk-memory -mreference-types \
 	-mnontrapping-fptoint -msign-ext \
-	-D_HAVE_SQLITE_CONFIG_H \
-	$(awk '{print "-Wl,--export="$0}' ../sqlite3/exports.txt)
+	-Wl,--initial-memory=327680 \
+	-Wl,--stack-first \
+	-Wl,--import-undefined \
+	$(awk '{print "-Wl,--export="$0}' exports.txt)
+
+trap 'rm -f sqlite3.tmp' EXIT
+"$BINARYEN/wasm-ctor-eval" -g -c _initialize sqlite3.wasm -o sqlite3.tmp
+"$BINARYEN/wasm-opt" -g -O2 sqlite3.tmp -o sqlite3.wasm \
+	--enable-multivalue --enable-mutable-globals \
+	--enable-bulk-memory --enable-reference-types \
+	--enable-nontrapping-float-to-int --enable-sign-ext

embed/exports.txt

@@ -37,13 +37,13 @@ sqlite3_blob_bytes
 sqlite3_blob_read
 sqlite3_blob_write
 sqlite3_blob_reopen
-sqlite3_get_autocommit
-sqlite3_last_insert_rowid
-sqlite3_changes64
-sqlite3_unlock_notify
 sqlite3_backup_init
 sqlite3_backup_step
 sqlite3_backup_finish
 sqlite3_backup_remaining
 sqlite3_backup_pagecount
-sqlite3_interrupt_offset
+sqlite3_uri_parameter
+sqlite3_uri_key
+sqlite3_changes64
+sqlite3_last_insert_rowid
+sqlite3_get_autocommit

embed/init.go

@@ -4,9 +4,6 @@
 // with an appropriate build of SQLite:
 //
 //	import _ "github.com/ncruces/go-sqlite3/embed"
-//
-// You can obtain this build of SQLite from:
-// https://github.com/ncruces/go-sqlite3/tree/main/embed
 package embed
 
 import (

error.go

@@ -1,20 +1,20 @@
 package sqlite3
 
 import (
-	"fmt"
-	"runtime"
 	"strconv"
 	"strings"
+
+	"github.com/ncruces/go-sqlite3/internal/util"
 )
 
 // Error wraps an SQLite Error Code.
 //
 // https://www.sqlite.org/c3ref/errcode.html
 type Error struct {
-	code uint64
 	str  string
 	msg  string
 	sql  string
+	code uint64
 }
 
 // Code returns the primary error code for this error.
@@ -85,72 +85,7 @@ func (e *Error) SQL() string {
 
 // Error implements the error interface.
 func (e ErrorCode) Error() string {
-	switch e {
-	case _OK:
-		return "sqlite3: not an error"
-	case _ROW:
-		return "sqlite3: another row available"
-	case _DONE:
-		return "sqlite3: no more rows available"
-
-	case ERROR:
-		return "sqlite3: SQL logic error"
-	case INTERNAL:
-		break
-	case PERM:
-		return "sqlite3: access permission denied"
-	case ABORT:
-		return "sqlite3: query aborted"
-	case BUSY:
-		return "sqlite3: database is locked"
-	case LOCKED:
-		return "sqlite3: database table is locked"
-	case NOMEM:
-		return "sqlite3: out of memory"
-	case READONLY:
-		return "sqlite3: attempt to write a readonly database"
-	case INTERRUPT:
-		return "sqlite3: interrupted"
-	case IOERR:
-		return "sqlite3: disk I/O error"
-	case CORRUPT:
-		return "sqlite3: database disk image is malformed"
-	case NOTFOUND:
-		return "sqlite3: unknown operation"
-	case FULL:
-		return "sqlite3: database or disk is full"
-	case CANTOPEN:
-		return "sqlite3: unable to open database file"
-	case PROTOCOL:
-		return "sqlite3: locking protocol"
-	case FORMAT:
-		break
-	case SCHEMA:
-		return "sqlite3: database schema has changed"
-	case TOOBIG:
-		return "sqlite3: string or blob too big"
-	case CONSTRAINT:
-		return "sqlite3: constraint failed"
-	case MISMATCH:
-		return "sqlite3: datatype mismatch"
-	case MISUSE:
-		return "sqlite3: bad parameter or other API misuse"
-	case NOLFS:
-		break
-	case AUTH:
-		return "sqlite3: authorization denied"
-	case EMPTY:
-		break
-	case RANGE:
-		return "sqlite3: column index out of range"
-	case NOTADB:
-		return "sqlite3: file is not a database"
-	case NOTICE:
-		return "sqlite3: notification message"
-	case WARNING:
-		return "sqlite3: warning message"
-	}
-	return "sqlite3: unknown error"
+	return util.ErrorCodeString(uint32(e))
 }
 
 // Temporary returns true for [BUSY] errors.
@@ -160,17 +95,7 @@ func (e ErrorCode) Temporary() bool {
 
 // Error implements the error interface.
 func (e ExtendedErrorCode) Error() string {
-	switch x := ErrorCode(e); {
-	case e == ABORT_ROLLBACK:
-		return "sqlite3: abort due to ROLLBACK"
-	case x < _ROW:
-		return x.Error()
-	case e == _ROW:
-		return "sqlite3: another row available"
-	case e == _DONE:
-		return "sqlite3: no more rows available"
-	}
-	return "sqlite3: unknown error"
+	return util.ErrorCodeString(uint32(e))
 }
 
 // Is tests whether this error matches a given [ErrorCode].
@@ -188,39 +113,3 @@ func (e ExtendedErrorCode) Temporary() bool {
 func (e ExtendedErrorCode) Timeout() bool {
 	return e == BUSY_TIMEOUT
 }
-
-type errorString string
-
-func (e errorString) Error() string { return string(e) }
-
-const (
-	nilErr      = errorString("sqlite3: invalid memory address or null pointer dereference")
-	oomErr      = errorString("sqlite3: out of memory")
-	rangeErr    = errorString("sqlite3: index out of range")
-	noNulErr    = errorString("sqlite3: missing NUL terminator")
-	noGlobalErr = errorString("sqlite3: could not find global: ")
-	noFuncErr   = errorString("sqlite3: could not find function: ")
-	binaryErr   = errorString("sqlite3: no SQLite binary embed/set/loaded")
-	timeErr     = errorString("sqlite3: invalid time value")
-	emptyErr    = errorString("sqlite3: empty statement")
-	tailErr     = errorString("sqlite3: non-empty tail")
-	notImplErr  = errorString("sqlite3: not implemented")
-	whenceErr   = errorString("sqlite3: invalid whence")
-	offsetErr   = errorString("sqlite3: invalid offset")
-)
-
-func assertErr() errorString {
-	msg := "sqlite3: assertion failed"
-	if _, file, line, ok := runtime.Caller(1); ok {
-		msg += " (" + file + ":" + strconv.Itoa(line) + ")"
-	}
-	return errorString(msg)
-}
-
-func finalizer[T any](skip int) func(*T) {
-	msg := fmt.Sprintf("sqlite3: %T not closed", new(T))
-	if _, file, line, ok := runtime.Caller(skip + 1); ok && skip >= 0 {
-		msg += " (" + file + ":" + strconv.Itoa(line) + ")"
-	}
-	return func(*T) { panic(errorString(msg)) }
-}

error_test.go

@@ -1,15 +1,16 @@
 package sqlite3
 
 import (
-	"context"
 	"errors"
 	"strings"
 	"testing"
+
+	"github.com/ncruces/go-sqlite3/internal/util"
 )
 
 func Test_assertErr(t *testing.T) {
-	err := assertErr()
-	if s := err.Error(); !strings.HasPrefix(s, "sqlite3: assertion failed") || !strings.HasSuffix(s, "error_test.go:11)") {
+	err := util.AssertErr()
+	if s := err.Error(); !strings.HasPrefix(s, "sqlite3: assertion failed") || !strings.HasSuffix(s, "error_test.go:12)") {
 		t.Errorf("got %q", s)
 	}
 }
@@ -120,10 +121,8 @@ func Test_ErrorCode_Error(t *testing.T) {
 	// Test all error codes.
 	for i := 0; i == int(ErrorCode(i)); i++ {
 		want := "sqlite3: "
-		r, _ := db.api.errstr.Call(context.TODO(), uint64(i))
-		if r != nil {
-			want += db.mem.readString(uint32(r[0]), _MAX_STRING)
-		}
+		r := db.call(db.api.errstr, uint64(i))
+		want += util.ReadString(db.mod, uint32(r), _MAX_STRING)
 
 		got := ErrorCode(i).Error()
 		if got != want {
@@ -144,10 +143,8 @@ func Test_ExtendedErrorCode_Error(t *testing.T) {
 	// Test all extended error codes.
 	for i := 0; i == int(ExtendedErrorCode(i)); i++ {
 		want := "sqlite3: "
-		r, _ := db.api.errstr.Call(context.TODO(), uint64(i))
-		if r != nil {
-			want += db.mem.readString(uint32(r[0]), _MAX_STRING)
-		}
+		r := db.call(db.api.errstr, uint64(i))
+		want += util.ReadString(db.mod, uint32(r), _MAX_STRING)
 
 		got := ExtendedErrorCode(i).Error()
 		if got != want {

example_test.go

@@ -26,7 +26,11 @@ func Example() {
 		log.Fatal(err)
 	}
 
-	stmt := db.MustPrepare(`SELECT id, name FROM users`)
+	stmt, _, err := db.Prepare(`SELECT id, name FROM users`)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer stmt.Close()
 
 	for stmt.Step() {
 		fmt.Println(stmt.ColumnInt(0), stmt.ColumnText(1))

go.mod

@@ -4,9 +4,10 @@ go 1.19
 
 require (
 	github.com/ncruces/julianday v0.1.5
-	github.com/tetratelabs/wazero v1.0.0-rc.1
-	golang.org/x/sync v0.1.0
-	golang.org/x/sys v0.6.0
+	github.com/psanford/httpreadat v0.1.0
+	github.com/tetratelabs/wazero v1.2.1
+	golang.org/x/sync v0.3.0
+	golang.org/x/sys v0.9.0
 )
 
 retract v0.4.0 // tagged from the wrong branch

go.sum

@@ -1,8 +1,10 @@
 github.com/ncruces/julianday v0.1.5 h1:hDJ9ejiMp3DHsoZ5KW4c1lwfMjbARS7u/gbYcd0FBZk=
 github.com/ncruces/julianday v0.1.5/go.mod h1:Dusn2KvZrrovOMJuOt0TNXL6tB7U2E8kvza5fFc9G7g=
-github.com/tetratelabs/wazero v1.0.0-rc.1 h1:ytecMV5Ue0BwezjKh/cM5yv1Mo49ep2R2snSsQUyToc=
-github.com/tetratelabs/wazero v1.0.0-rc.1/go.mod h1:wYx2gNRg8/WihJfSDxA1TIL8H+GkfLYm+bIfbblu9VQ=
-golang.org/x/sync v0.1.0 h1:wsuoTGHzEhffawBOhz5CYhcrV4IdKZbEyZjBMuTp12o=
-golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sys v0.6.0 h1:MVltZSvRTcU2ljQOhs94SXPftV6DCNnZViHeQps87pQ=
-golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+github.com/psanford/httpreadat v0.1.0 h1:VleW1HS2zO7/4c7c7zNl33fO6oYACSagjJIyMIwZLUE=
+github.com/psanford/httpreadat v0.1.0/go.mod h1:Zg7P+TlBm3bYbyHTKv/EdtSJZn3qwbPwpfZ/I9GKCRE=
+github.com/tetratelabs/wazero v1.2.1 h1:J4X2hrGzJvt+wqltuvcSjHQ7ujQxA9gb6PeMs4qlUWs=
+github.com/tetratelabs/wazero v1.2.1/go.mod h1:wYx2gNRg8/WihJfSDxA1TIL8H+GkfLYm+bIfbblu9VQ=
+golang.org/x/sync v0.3.0 h1:ftCYgMx6zT/asHUrPw8BLLscYtGznsLAnjq5RH9P66E=
+golang.org/x/sync v0.3.0/go.mod h1:FU7BRWz2tNW+3quACPkgCx/L+uEAv1htQ0V83Z9Rj+Y=
+golang.org/x/sys v0.9.0 h1:KS/R3tvhPqvJvwcKfnBHJwwthS11LRhmM5D59eEXa0s=
+golang.org/x/sys v0.9.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

go.work

@@ -0,0 +1,6 @@
+go 1.19
+
+use (
+	.
+	./gormlite
+)

gormlite/LICENSE

@@ -0,0 +1,22 @@
+MIT License
+
+Copyright (c) 2023 Nuno Cruces
+Copyright (c) 2023 Jinzhu <wosmvp@gmail.com>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

gormlite/README.md

@@ -0,0 +1,26 @@
+# GORM SQLite Driver
+
+[![Go Reference](https://pkg.go.dev/badge/image)](https://pkg.go.dev/github.com/ncruces/go-sqlite3/gormlite)
+
+## Usage
+
+```go
+import (
+	_ "github.com/ncruces/go-sqlite3/embed"
+	"github.com/ncruces/go-sqlite3/gormlite"
+	"gorm.io/gorm"
+)
+
+db, err := gorm.Open(gormlite.Open("gorm.db"), &gorm.Config{})
+```
+
+Checkout [https://gorm.io](https://gorm.io) for details.
+
+### Foreign-key constraint activation
+
+Foreign-key constraint is disabled by default in SQLite. To activate it, use connection URL parameter:
+```go
+db, err := gorm.Open(gormlite.Open(
+	"file:gorm.db?_pragma=busy_timeout(10000)&_pragma=locking_mode(normal)&_pragma=foreign_keys(1)"),
+	&gorm.Config{})
+```

gormlite/ddlmod.go

@@ -0,0 +1,231 @@
+package gormlite
+
+import (
+	"database/sql"
+	"errors"
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"gorm.io/gorm/migrator"
+)
+
+var (
+	sqliteSeparator    = "`|\"|'|\t"
+	indexRegexp        = regexp.MustCompile(fmt.Sprintf(`(?is)CREATE(?: UNIQUE)? INDEX [%v]?[\w\d-]+[%v]? ON (.*)$`, sqliteSeparator, sqliteSeparator))
+	tableRegexp        = regexp.MustCompile(fmt.Sprintf(`(?is)(CREATE TABLE [%v]?[\w\d-]+[%v]?)(?:\s*\((.*)\))?`, sqliteSeparator, sqliteSeparator))
+	separatorRegexp    = regexp.MustCompile(fmt.Sprintf("[%v]", sqliteSeparator))
+	columnsRegexp      = regexp.MustCompile(fmt.Sprintf(`[(,][%v]?(\w+)[%v]?`, sqliteSeparator, sqliteSeparator))
+	columnRegexp       = regexp.MustCompile(fmt.Sprintf(`^[%v]?([\w\d]+)[%v]?\s+([\w\(\)\d]+)(.*)$`, sqliteSeparator, sqliteSeparator))
+	defaultValueRegexp = regexp.MustCompile(`(?i) DEFAULT \(?(.+)?\)?( |COLLATE|GENERATED|$)`)
+	regRealDataType    = regexp.MustCompile(`[^\d](\d+)[^\d]?`)
+)
+
+func getAllColumns(s string) []string {
+	allMatches := columnsRegexp.FindAllStringSubmatch(s, -1)
+	columns := make([]string, 0, len(allMatches))
+	for _, matches := range allMatches {
+		if len(matches) > 1 {
+			columns = append(columns, matches[1])
+		}
+	}
+	return columns
+}
+
+type ddl struct {
+	head    string
+	fields  []string
+	columns []migrator.ColumnType
+}
+
+func parseDDL(strs ...string) (*ddl, error) {
+	var result ddl
+	for _, str := range strs {
+		if sections := tableRegexp.FindStringSubmatch(str); len(sections) > 0 {
+			var (
+				ddlBody      = sections[2]
+				ddlBodyRunes = []rune(ddlBody)
+				bracketLevel int
+				quote        rune
+				buf          string
+			)
+			ddlBodyRunesLen := len(ddlBodyRunes)
+
+			result.head = sections[1]
+
+			for idx := 0; idx < ddlBodyRunesLen; idx++ {
+				var (
+					next rune = 0
+					c         = ddlBodyRunes[idx]
+				)
+				if idx+1 < ddlBodyRunesLen {
+					next = ddlBodyRunes[idx+1]
+				}
+
+				if sc := string(c); separatorRegexp.MatchString(sc) {
+					if c == next {
+						buf += sc // Skip escaped quote
+						idx++
+					} else if quote > 0 {
+						quote = 0
+					} else {
+						quote = c
+					}
+				} else if quote == 0 {
+					if c == '(' {
+						bracketLevel++
+					} else if c == ')' {
+						bracketLevel--
+					} else if bracketLevel == 0 {
+						if c == ',' {
+							result.fields = append(result.fields, strings.TrimSpace(buf))
+							buf = ""
+							continue
+						}
+					}
+				}
+
+				if bracketLevel < 0 {
+					return nil, errors.New("invalid DDL, unbalanced brackets")
+				}
+
+				buf += string(c)
+			}
+
+			if bracketLevel != 0 {
+				return nil, errors.New("invalid DDL, unbalanced brackets")
+			}
+
+			if buf != "" {
+				result.fields = append(result.fields, strings.TrimSpace(buf))
+			}
+
+			for _, f := range result.fields {
+				fUpper := strings.ToUpper(f)
+				if strings.HasPrefix(fUpper, "CHECK") ||
+					strings.HasPrefix(fUpper, "CONSTRAINT") {
+					continue
+				}
+
+				if strings.HasPrefix(fUpper, "PRIMARY KEY") {
+					for _, name := range getAllColumns(f) {
+						for idx, column := range result.columns {
+							if column.NameValue.String == name {
+								column.PrimaryKeyValue = sql.NullBool{Bool: true, Valid: true}
+								result.columns[idx] = column
+								break
+							}
+						}
+					}
+				} else if matches := columnRegexp.FindStringSubmatch(f); len(matches) > 0 {
+					columnType := migrator.ColumnType{
+						NameValue:         sql.NullString{String: matches[1], Valid: true},
+						DataTypeValue:     sql.NullString{String: matches[2], Valid: true},
+						ColumnTypeValue:   sql.NullString{String: matches[2], Valid: true},
+						PrimaryKeyValue:   sql.NullBool{Valid: true},
+						UniqueValue:       sql.NullBool{Valid: true},
+						NullableValue:     sql.NullBool{Valid: true},
+						DefaultValueValue: sql.NullString{Valid: false},
+					}
+
+					matchUpper := strings.ToUpper(matches[3])
+					if strings.Contains(matchUpper, " NOT NULL") {
+						columnType.NullableValue = sql.NullBool{Bool: false, Valid: true}
+					} else if strings.Contains(matchUpper, " NULL") {
+						columnType.NullableValue = sql.NullBool{Bool: true, Valid: true}
+					}
+					if strings.Contains(matchUpper, " UNIQUE") {
+						columnType.UniqueValue = sql.NullBool{Bool: true, Valid: true}
+					}
+					if strings.Contains(matchUpper, " PRIMARY") {
+						columnType.PrimaryKeyValue = sql.NullBool{Bool: true, Valid: true}
+					}
+					if defaultMatches := defaultValueRegexp.FindStringSubmatch(matches[3]); len(defaultMatches) > 1 {
+						if strings.ToLower(defaultMatches[1]) != "null" {
+							columnType.DefaultValueValue = sql.NullString{String: strings.Trim(defaultMatches[1], `"`), Valid: true}
+						}
+					}
+
+					// data type length
+					matches := regRealDataType.FindAllStringSubmatch(columnType.DataTypeValue.String, -1)
+					if len(matches) == 1 && len(matches[0]) == 2 {
+						size, _ := strconv.Atoi(matches[0][1])
+						columnType.LengthValue = sql.NullInt64{Valid: true, Int64: int64(size)}
+						columnType.DataTypeValue.String = strings.TrimSuffix(columnType.DataTypeValue.String, matches[0][0])
+					}
+
+					result.columns = append(result.columns, columnType)
+				}
+			}
+		} else if matches := indexRegexp.FindStringSubmatch(str); len(matches) > 0 {
+			for _, column := range getAllColumns(matches[1]) {
+				for idx, c := range result.columns {
+					if c.NameValue.String == column {
+						c.UniqueValue = sql.NullBool{Bool: strings.ToUpper(strings.Fields(str)[1]) == "UNIQUE", Valid: true}
+						result.columns[idx] = c
+					}
+				}
+			}
+		} else {
+			return nil, errors.New("invalid DDL")
+		}
+	}
+
+	return &result, nil
+}
+
+func (d *ddl) compile() string {
+	if len(d.fields) == 0 {
+		return d.head
+	}
+
+	return fmt.Sprintf("%s (%s)", d.head, strings.Join(d.fields, ","))
+}
+
+func (d *ddl) addConstraint(name string, sql string) {
+	reg := regexp.MustCompile("^CONSTRAINT [\"`]?" + regexp.QuoteMeta(name) + "[\"` ]")
+
+	for i := 0; i < len(d.fields); i++ {
+		if reg.MatchString(d.fields[i]) {
+			d.fields[i] = sql
+			return
+		}
+	}
+
+	d.fields = append(d.fields, sql)
+}
+
+func (d *ddl) removeConstraint(name string) bool {
+	reg := regexp.MustCompile("^CONSTRAINT [\"`]?" + regexp.QuoteMeta(name) + "[\"` ]")
+
+	for i := 0; i < len(d.fields); i++ {
+		if reg.MatchString(d.fields[i]) {
+			d.fields = append(d.fields[:i], d.fields[i+1:]...)
+			return true
+		}
+	}
+	return false
+}
+
+func (d *ddl) getColumns() []string {
+	res := []string{}
+
+	for _, f := range d.fields {
+		fUpper := strings.ToUpper(f)
+		if strings.HasPrefix(fUpper, "PRIMARY KEY") ||
+			strings.HasPrefix(fUpper, "CHECK") ||
+			strings.HasPrefix(fUpper, "CONSTRAINT") ||
+			strings.Contains(fUpper, "GENERATED ALWAYS AS") {
+			continue
+		}
+
+		reg := regexp.MustCompile("^[\"`']?([\\w\\d]+)[\"`']?")
+		match := reg.FindStringSubmatch(f)
+
+		if match != nil {
+			res = append(res, "`"+match[1]+"`")
+		}
+	}
+	return res
+}

gormlite/ddlmod_test.go

@@ -0,0 +1,352 @@
+package gormlite
+
+import (
+	"database/sql"
+	"testing"
+
+	"gorm.io/gorm/migrator"
+	"gorm.io/gorm/utils/tests"
+)
+
+func TestParseDDL(t *testing.T) {
+	params := []struct {
+		name    string
+		sql     []string
+		nFields int
+		columns []migrator.ColumnType
+	}{
+		{"with_fk", []string{
+			"CREATE TABLE `notes` (`id` integer NOT NULL,`text` varchar(500) DEFAULT \"hello\",`age` integer DEFAULT 18,`user_id` integer,PRIMARY KEY (`id`),CONSTRAINT `fk_users_notes` FOREIGN KEY (`user_id`) REFERENCES `users`(`id`))",
+			"CREATE UNIQUE INDEX `idx_profiles_refer` ON `profiles`(`text`)",
+		}, 6, []migrator.ColumnType{
+			{NameValue: sql.NullString{String: "id", Valid: true}, DataTypeValue: sql.NullString{String: "integer", Valid: true}, ColumnTypeValue: sql.NullString{String: "integer", Valid: true}, PrimaryKeyValue: sql.NullBool{Bool: true, Valid: true}, NullableValue: sql.NullBool{Valid: true}, UniqueValue: sql.NullBool{Valid: true}, DefaultValueValue: sql.NullString{Valid: false}},
+			{NameValue: sql.NullString{String: "text", Valid: true}, DataTypeValue: sql.NullString{String: "varchar", Valid: true}, LengthValue: sql.NullInt64{Int64: 500, Valid: true}, ColumnTypeValue: sql.NullString{String: "varchar(500)", Valid: true}, DefaultValueValue: sql.NullString{String: "hello", Valid: true}, NullableValue: sql.NullBool{Valid: true}, UniqueValue: sql.NullBool{Bool: true, Valid: true}, PrimaryKeyValue: sql.NullBool{Valid: true}},
+			{NameValue: sql.NullString{String: "age", Valid: true}, DataTypeValue: sql.NullString{String: "integer", Valid: true}, ColumnTypeValue: sql.NullString{String: "integer", Valid: true}, DefaultValueValue: sql.NullString{String: "18", Valid: true}, NullableValue: sql.NullBool{Valid: true}, UniqueValue: sql.NullBool{Valid: true}, PrimaryKeyValue: sql.NullBool{Valid: true}},
+			{NameValue: sql.NullString{String: "user_id", Valid: true}, DataTypeValue: sql.NullString{String: "integer", Valid: true}, ColumnTypeValue: sql.NullString{String: "integer", Valid: true}, DefaultValueValue: sql.NullString{Valid: false}, NullableValue: sql.NullBool{Valid: true}, UniqueValue: sql.NullBool{Valid: true}, PrimaryKeyValue: sql.NullBool{Valid: true}},
+		},
+		},
+		{"with_check", []string{"CREATE TABLE Persons (ID int NOT NULL,LastName varchar(255) NOT NULL,FirstName varchar(255),Age int,CHECK (Age>=18),CHECK (FirstName<>'John'))"}, 6, []migrator.ColumnType{
+			{NameValue: sql.NullString{String: "ID", Valid: true}, DataTypeValue: sql.NullString{String: "int", Valid: true}, ColumnTypeValue: sql.NullString{String: "int", Valid: true}, NullableValue: sql.NullBool{Valid: true}, DefaultValueValue: sql.NullString{Valid: false}, UniqueValue: sql.NullBool{Valid: true}, PrimaryKeyValue: sql.NullBool{Valid: true}},
+			{NameValue: sql.NullString{String: "LastName", Valid: true}, DataTypeValue: sql.NullString{String: "varchar", Valid: true}, LengthValue: sql.NullInt64{Int64: 255, Valid: true}, ColumnTypeValue: sql.NullString{String: "varchar(255)", Valid: true}, NullableValue: sql.NullBool{Bool: false, Valid: true}, DefaultValueValue: sql.NullString{Valid: false}, UniqueValue: sql.NullBool{Valid: true}, PrimaryKeyValue: sql.NullBool{Valid: true}},
+			{NameValue: sql.NullString{String: "FirstName", Valid: true}, DataTypeValue: sql.NullString{String: "varchar", Valid: true}, LengthValue: sql.NullInt64{Int64: 255, Valid: true}, ColumnTypeValue: sql.NullString{String: "varchar(255)", Valid: true}, DefaultValueValue: sql.NullString{Valid: false}, NullableValue: sql.NullBool{Valid: true}, UniqueValue: sql.NullBool{Valid: true}, PrimaryKeyValue: sql.NullBool{Valid: true}},
+			{NameValue: sql.NullString{String: "Age", Valid: true}, DataTypeValue: sql.NullString{String: "int", Valid: true}, ColumnTypeValue: sql.NullString{String: "int", Valid: true}, DefaultValueValue: sql.NullString{Valid: false}, NullableValue: sql.NullBool{Valid: true}, UniqueValue: sql.NullBool{Valid: true}, PrimaryKeyValue: sql.NullBool{Valid: true}},
+		}},
+		{"lowercase", []string{"create table test (ID int NOT NULL)"}, 1, []migrator.ColumnType{
+			{NameValue: sql.NullString{String: "ID", Valid: true}, DataTypeValue: sql.NullString{String: "int", Valid: true}, ColumnTypeValue: sql.NullString{String: "int", Valid: true}, NullableValue: sql.NullBool{Bool: false, Valid: true}, DefaultValueValue: sql.NullString{Valid: false}, UniqueValue: sql.NullBool{Valid: true}, PrimaryKeyValue: sql.NullBool{Valid: true}},
+		},
+		},
+		{"no brackets", []string{"create table test"}, 0, nil},
+		{"with_special_characters", []string{
+			"CREATE TABLE `test` (`text` varchar(10) DEFAULT \"测试, \")",
+		}, 1, []migrator.ColumnType{
+			{NameValue: sql.NullString{String: "text", Valid: true}, DataTypeValue: sql.NullString{String: "varchar", Valid: true}, LengthValue: sql.NullInt64{Int64: 10, Valid: true}, ColumnTypeValue: sql.NullString{String: "varchar(10)", Valid: true}, DefaultValueValue: sql.NullString{String: "测试, ", Valid: true}, NullableValue: sql.NullBool{Valid: true}, UniqueValue: sql.NullBool{Valid: true}, PrimaryKeyValue: sql.NullBool{Valid: true}},
+		},
+		},
+		{
+			"table_name_with_dash",
+			[]string{
+				"CREATE TABLE `test-a` (`id` int NOT NULL)",
+				"CREATE UNIQUE INDEX `idx_test-a_id` ON `test-a`(`id`)",
+			},
+			1,
+			[]migrator.ColumnType{
+				{
+					NameValue:         sql.NullString{String: "id", Valid: true},
+					DataTypeValue:     sql.NullString{String: "int", Valid: true},
+					ColumnTypeValue:   sql.NullString{String: "int", Valid: true},
+					NullableValue:     sql.NullBool{Bool: false, Valid: true},
+					DefaultValueValue: sql.NullString{Valid: false},
+					UniqueValue:       sql.NullBool{Bool: true, Valid: true},
+					PrimaryKeyValue:   sql.NullBool{Valid: true},
+				},
+			},
+		},
+		{
+			"unique index",
+			[]string{
+				"CREATE TABLE `test-b` (`field` integer NOT NULL)",
+				"CREATE UNIQUE INDEX `idx_uq` ON `test-b`(`field`) WHERE field = 0",
+			},
+			1,
+			[]migrator.ColumnType{
+				{
+					NameValue:       sql.NullString{String: "field", Valid: true},
+					DataTypeValue:   sql.NullString{String: "integer", Valid: true},
+					ColumnTypeValue: sql.NullString{String: "integer", Valid: true},
+					PrimaryKeyValue: sql.NullBool{Bool: false, Valid: true},
+					UniqueValue:     sql.NullBool{Bool: true, Valid: true},
+					NullableValue:   sql.NullBool{Bool: false, Valid: true},
+				},
+			},
+		},
+		{
+			"non-unique index",
+			[]string{
+				"CREATE TABLE `test-c` (`field` integer NOT NULL)",
+				"CREATE INDEX `idx_uq` ON `test-b`(`field`) WHERE field = 0",
+			},
+			1,
+			[]migrator.ColumnType{
+				{
+					NameValue:       sql.NullString{String: "field", Valid: true},
+					DataTypeValue:   sql.NullString{String: "integer", Valid: true},
+					ColumnTypeValue: sql.NullString{String: "integer", Valid: true},
+					PrimaryKeyValue: sql.NullBool{Bool: false, Valid: true},
+					UniqueValue:     sql.NullBool{Bool: false, Valid: true},
+					NullableValue:   sql.NullBool{Bool: false, Valid: true},
+				},
+			},
+		},
+	}
+
+	for _, p := range params {
+		t.Run(p.name, func(t *testing.T) {
+			ddl, err := parseDDL(p.sql...)
+
+			if err != nil {
+				panic(err.Error())
+			}
+
+			tests.AssertEqual(t, p.sql[0], ddl.compile())
+			if len(ddl.fields) != p.nFields {
+				t.Fatalf("fields length doesn't match: expect: %v, got %v", p.nFields, len(ddl.fields))
+			}
+			tests.AssertEqual(t, ddl.columns, p.columns)
+		})
+	}
+}
+
+func TestParseDDL_Whitespaces(t *testing.T) {
+	testColumns := []migrator.ColumnType{
+		{
+			NameValue:         sql.NullString{String: "id", Valid: true},
+			DataTypeValue:     sql.NullString{String: "integer", Valid: true},
+			ColumnTypeValue:   sql.NullString{String: "integer", Valid: true},
+			NullableValue:     sql.NullBool{Bool: false, Valid: true},
+			DefaultValueValue: sql.NullString{Valid: false},
+			UniqueValue:       sql.NullBool{Bool: true, Valid: true},
+			PrimaryKeyValue:   sql.NullBool{Bool: true, Valid: true},
+		},
+		{
+			NameValue:         sql.NullString{String: "dark_mode", Valid: true},
+			DataTypeValue:     sql.NullString{String: "numeric", Valid: true},
+			ColumnTypeValue:   sql.NullString{String: "numeric", Valid: true},
+			NullableValue:     sql.NullBool{Valid: true},
+			DefaultValueValue: sql.NullString{String: "true", Valid: true},
+			UniqueValue:       sql.NullBool{Bool: false, Valid: true},
+			PrimaryKeyValue:   sql.NullBool{Bool: false, Valid: true},
+		},
+	}
+
+	params := []struct {
+		name    string
+		sql     []string
+		nFields int
+		columns []migrator.ColumnType
+	}{
+		{
+			"with_newline",
+			[]string{"CREATE TABLE `users`\n(\nid integer primary key unique,\ndark_mode numeric DEFAULT true)"},
+			2,
+			testColumns,
+		},
+		{
+			"with_newline_2",
+			[]string{"CREATE TABLE `users` (\n\nid integer primary key unique,\ndark_mode numeric DEFAULT true)"},
+			2,
+			testColumns,
+		},
+		{
+			"with_missing_space",
+			[]string{"CREATE TABLE `users`(id integer primary key unique, dark_mode numeric DEFAULT true)"},
+			2,
+			testColumns,
+		},
+		{
+			"with_many_spaces",
+			[]string{"CREATE TABLE `users`       (id    integer   primary key unique,     dark_mode    numeric DEFAULT true)"},
+			2,
+			testColumns,
+		},
+	}
+	for _, p := range params {
+		t.Run(p.name, func(t *testing.T) {
+			ddl, err := parseDDL(p.sql...)
+
+			if err != nil {
+				panic(err.Error())
+			}
+
+			if len(ddl.fields) != p.nFields {
+				t.Fatalf("fields length doesn't match: expect: %v, got %v", p.nFields, len(ddl.fields))
+			}
+			tests.AssertEqual(t, ddl.columns, p.columns)
+		})
+	}
+}
+
+func TestParseDDL_error(t *testing.T) {
+	params := []struct {
+		name string
+		sql  string
+	}{
+		{"invalid_cmd", "CREATE TABLE"},
+		{"unbalanced_brackets", "CREATE TABLE test (ID int NOT NULL,Name varchar(255)"},
+		{"unbalanced_brackets2", "CREATE TABLE test (ID int NOT NULL,Name varchar(255)))"},
+	}
+
+	for _, p := range params {
+		t.Run(p.name, func(t *testing.T) {
+			_, err := parseDDL(p.sql)
+			if err == nil {
+				t.Fail()
+			}
+		})
+	}
+}
+
+func TestAddConstraint(t *testing.T) {
+	params := []struct {
+		name   string
+		fields []string
+		cName  string
+		sql    string
+		expect []string
+	}{
+		{
+			name:   "add_new",
+			fields: []string{"`id` integer NOT NULL"},
+			cName:  "fk_users_notes",
+			sql:    "CONSTRAINT `fk_users_notes` FOREIGN KEY (`user_id`) REFERENCES `users`(`id`))",
+			expect: []string{"`id` integer NOT NULL", "CONSTRAINT `fk_users_notes` FOREIGN KEY (`user_id`) REFERENCES `users`(`id`))"},
+		},
+		{
+			name:   "update",
+			fields: []string{"`id` integer NOT NULL", "CONSTRAINT `fk_users_notes` FOREIGN KEY (`user_id`) REFERENCES `users`(`id`))"},
+			cName:  "fk_users_notes",
+			sql:    "CONSTRAINT `fk_users_notes` FOREIGN KEY (`user_id`) REFERENCES `users`(`id`)) ON UPDATE CASCADE ON DELETE CASCADE",
+			expect: []string{"`id` integer NOT NULL", "CONSTRAINT `fk_users_notes` FOREIGN KEY (`user_id`) REFERENCES `users`(`id`)) ON UPDATE CASCADE ON DELETE CASCADE"},
+		},
+		{
+			name:   "add_check",
+			fields: []string{"`id` integer NOT NULL"},
+			cName:  "name_checker",
+			sql:    "CONSTRAINT `name_checker` CHECK (`name` <> 'jinzhu')",
+			expect: []string{"`id` integer NOT NULL", "CONSTRAINT `name_checker` CHECK (`name` <> 'jinzhu')"},
+		},
+		{
+			name:   "update_check",
+			fields: []string{"`id` integer NOT NULL", "CONSTRAINT `name_checker` CHECK (`name` <> 'thetadev')"},
+			cName:  "name_checker",
+			sql:    "CONSTRAINT `name_checker` CHECK (`name` <> 'jinzhu')",
+			expect: []string{"`id` integer NOT NULL", "CONSTRAINT `name_checker` CHECK (`name` <> 'jinzhu')"},
+		},
+	}
+
+	for _, p := range params {
+		t.Run(p.name, func(t *testing.T) {
+			testDDL := ddl{fields: p.fields}
+
+			testDDL.addConstraint(p.cName, p.sql)
+			tests.AssertEqual(t, p.expect, testDDL.fields)
+		})
+	}
+}
+
+func TestRemoveConstraint(t *testing.T) {
+	params := []struct {
+		name    string
+		fields  []string
+		cName   string
+		success bool
+		expect  []string
+	}{
+		{
+			name:    "fk",
+			fields:  []string{"`id` integer NOT NULL", "CONSTRAINT `fk_users_notes` FOREIGN KEY (`user_id`) REFERENCES `users`(`id`))"},
+			cName:   "fk_users_notes",
+			success: true,
+			expect:  []string{"`id` integer NOT NULL"},
+		},
+		{
+			name:    "check",
+			fields:  []string{"CONSTRAINT `name_checker` CHECK (`name` <> 'thetadev')", "`id` integer NOT NULL"},
+			cName:   "name_checker",
+			success: true,
+			expect:  []string{"`id` integer NOT NULL"},
+		},
+		{
+			name:    "none",
+			fields:  []string{"CONSTRAINT `name_checker` CHECK (`name` <> 'thetadev')", "`id` integer NOT NULL"},
+			cName:   "nothing",
+			success: false,
+			expect:  []string{"CONSTRAINT `name_checker` CHECK (`name` <> 'thetadev')", "`id` integer NOT NULL"},
+		},
+	}
+
+	for _, p := range params {
+		t.Run(p.name, func(t *testing.T) {
+			testDDL := ddl{fields: p.fields}
+
+			success := testDDL.removeConstraint(p.cName)
+
+			tests.AssertEqual(t, p.success, success)
+			tests.AssertEqual(t, p.expect, testDDL.fields)
+		})
+	}
+}
+
+func TestGetColumns(t *testing.T) {
+	params := []struct {
+		name    string
+		ddl     string
+		columns []string
+	}{
+		{
+			name:    "with_fk",
+			ddl:     "CREATE TABLE `notes` (`id` integer NOT NULL,`text` varchar(500),`user_id` integer,PRIMARY KEY (`id`),CONSTRAINT `fk_users_notes` FOREIGN KEY (`user_id`) REFERENCES `users`(`id`))",
+			columns: []string{"`id`", "`text`", "`user_id`"},
+		},
+		{
+			name:    "with_check",
+			ddl:     "CREATE TABLE Persons (ID int NOT NULL,LastName varchar(255) NOT NULL,FirstName varchar(255),Age int,CHECK (Age>=18),CHECK (FirstName!='John'))",
+			columns: []string{"`ID`", "`LastName`", "`FirstName`", "`Age`"},
+		},
+		{
+			name:    "with_escaped_quote",
+			ddl:     "CREATE TABLE Persons (ID int NOT NULL,LastName varchar(255) NOT NULL DEFAULT \"\",FirstName varchar(255))",
+			columns: []string{"`ID`", "`LastName`", "`FirstName`"},
+		},
+		{
+			name:    "with_generated_column",
+			ddl:     "CREATE TABLE Persons (ID int NOT NULL,LastName varchar(255) NOT NULL,FirstName varchar(255),FullName varchar(255) GENERATED ALWAYS AS (FirstName || ' ' || LastName))",
+			columns: []string{"`ID`", "`LastName`", "`FirstName`"},
+		},
+		{
+			name: "with_new_line",
+			ddl: `CREATE TABLE "tb_sys_role_menu__temp" (
+  "id" integer  PRIMARY KEY AUTOINCREMENT,
+  "created_at" datetime NOT NULL,
+  "updated_at" datetime NOT NULL,
+  "created_by" integer NOT NULL DEFAULT 0,
+  "updated_by" integer NOT NULL DEFAULT 0,
+  "role_id" integer NOT NULL,
+  "menu_id" bigint NOT NULL
+)`,
+			columns: []string{"`id`", "`created_at`", "`updated_at`", "`created_by`", "`updated_by`", "`role_id`", "`menu_id`"},
+		},
+	}
+
+	for _, p := range params {
+		t.Run(p.name, func(t *testing.T) {
+			testDDL, err := parseDDL(p.ddl)
+			if err != nil {
+				panic(err.Error())
+			}
+
+			cols := testDDL.getColumns()
+
+			tests.AssertEqual(t, p.columns, cols)
+		})
+	}
+}

gormlite/download.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+cd -P -- "$(dirname -- "$0")"
+
+curl -#OL "https://github.com/go-gorm/sqlite/raw/master/ddlmod.go"
+curl -#OL "https://github.com/go-gorm/sqlite/raw/master/ddlmod_test.go"
+curl -#OL "https://github.com/go-gorm/sqlite/raw/master/error_translator.go"
+curl -#OL "https://github.com/go-gorm/sqlite/raw/master/migrator.go"
+curl -#OL "https://github.com/go-gorm/sqlite/raw/master/sqlite.go"
+curl -#OL "https://github.com/go-gorm/sqlite/raw/master/sqlite_test.go"

gormlite/error_translator.go

@@ -0,0 +1,21 @@
+package gormlite
+
+import (
+	"errors"
+
+	"github.com/ncruces/go-sqlite3"
+	"gorm.io/gorm"
+)
+
+func (dialector Dialector) Translate(err error) error {
+	switch {
+	case
+		errors.Is(err, sqlite3.CONSTRAINT_UNIQUE),
+		errors.Is(err, sqlite3.CONSTRAINT_PRIMARYKEY):
+		return gorm.ErrDuplicatedKey
+	case
+		errors.Is(err, sqlite3.CONSTRAINT_FOREIGNKEY):
+		return err // gorm.ErrForeignKeyViolated (gorm v1.25.2)
+	}
+	return err
+}

gormlite/go.mod

@@ -0,0 +1,16 @@
+module github.com/ncruces/go-sqlite3/gormlite
+
+go 1.19
+
+require (
+	github.com/ncruces/go-sqlite3 v0.7.3
+	gorm.io/gorm v1.25.1
+)
+
+require (
+	github.com/jinzhu/inflection v1.0.0 // indirect
+	github.com/jinzhu/now v1.1.5 // indirect
+	github.com/ncruces/julianday v0.1.5 // indirect
+	github.com/tetratelabs/wazero v1.2.1 // indirect
+	golang.org/x/sys v0.9.0 // indirect
+)

gormlite/go.sum

@@ -0,0 +1,14 @@
+github.com/jinzhu/inflection v1.0.0 h1:K317FqzuhWc8YvSVlFMCCUb36O/S9MCKRDI7QkRKD/E=
+github.com/jinzhu/inflection v1.0.0/go.mod h1:h+uFLlag+Qp1Va5pdKtLDYj+kHp5pxUVkryuEj+Srlc=
+github.com/jinzhu/now v1.1.5 h1:/o9tlHleP7gOFmsnYNz3RGnqzefHA47wQpKrrdTIwXQ=
+github.com/jinzhu/now v1.1.5/go.mod h1:d3SSVoowX0Lcu0IBviAWJpolVfI5UJVZZ7cO71lE/z8=
+github.com/ncruces/go-sqlite3 v0.7.3 h1:yX9GebkDvaf1Z+VnxY77Od7GbWTWFCq9yvNzYJYMsaY=
+github.com/ncruces/go-sqlite3 v0.7.3/go.mod h1:EhHe1qvG6Zc/8ffYMzre8n//rTRs1YNN5dUD1f1mEGc=
+github.com/ncruces/julianday v0.1.5 h1:hDJ9ejiMp3DHsoZ5KW4c1lwfMjbARS7u/gbYcd0FBZk=
+github.com/ncruces/julianday v0.1.5/go.mod h1:Dusn2KvZrrovOMJuOt0TNXL6tB7U2E8kvza5fFc9G7g=
+github.com/tetratelabs/wazero v1.2.1 h1:J4X2hrGzJvt+wqltuvcSjHQ7ujQxA9gb6PeMs4qlUWs=
+github.com/tetratelabs/wazero v1.2.1/go.mod h1:wYx2gNRg8/WihJfSDxA1TIL8H+GkfLYm+bIfbblu9VQ=
+golang.org/x/sys v0.9.0 h1:KS/R3tvhPqvJvwcKfnBHJwwthS11LRhmM5D59eEXa0s=
+golang.org/x/sys v0.9.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+gorm.io/gorm v1.25.1 h1:nsSALe5Pr+cM3V1qwwQ7rOkw+6UeLrX5O4v3llhHa64=
+gorm.io/gorm v1.25.1/go.mod h1:L4uxeKpfBml98NYqVqwAdmV1a2nBtAec/cf3fpucW/k=

gormlite/migrator.go

@@ -0,0 +1,431 @@
+package gormlite
+
+import (
+	"database/sql"
+	"fmt"
+	"regexp"
+	"strings"
+
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+	"gorm.io/gorm/migrator"
+	"gorm.io/gorm/schema"
+)
+
+type Migrator struct {
+	migrator.Migrator
+}
+
+func (m *Migrator) RunWithoutForeignKey(fc func() error) error {
+	var enabled int
+	m.DB.Raw("PRAGMA foreign_keys").Scan(&enabled)
+	if enabled == 1 {
+		m.DB.Exec("PRAGMA foreign_keys = OFF")
+		defer m.DB.Exec("PRAGMA foreign_keys = ON")
+	}
+
+	return fc()
+}
+
+func (m Migrator) HasTable(value interface{}) bool {
+	var count int
+	m.Migrator.RunWithValue(value, func(stmt *gorm.Statement) error {
+		return m.DB.Raw("SELECT count(*) FROM sqlite_master WHERE type='table' AND name=?", stmt.Table).Row().Scan(&count)
+	})
+	return count > 0
+}
+
+func (m Migrator) DropTable(values ...interface{}) error {
+	return m.RunWithoutForeignKey(func() error {
+		values = m.ReorderModels(values, false)
+		tx := m.DB.Session(&gorm.Session{})
+
+		for i := len(values) - 1; i >= 0; i-- {
+			if err := m.RunWithValue(values[i], func(stmt *gorm.Statement) error {
+				return tx.Exec("DROP TABLE IF EXISTS ?", clause.Table{Name: stmt.Table}).Error
+			}); err != nil {
+				return err
+			}
+		}
+
+		return nil
+	})
+}
+
+func (m Migrator) GetTables() (tableList []string, err error) {
+	return tableList, m.DB.Raw("SELECT name FROM sqlite_master where type=?", "table").Scan(&tableList).Error
+}
+
+func (m Migrator) HasColumn(value interface{}, name string) bool {
+	var count int
+	m.Migrator.RunWithValue(value, func(stmt *gorm.Statement) error {
+		if stmt.Schema != nil {
+			if field := stmt.Schema.LookUpField(name); field != nil {
+				name = field.DBName
+			}
+		}
+
+		if name != "" {
+			m.DB.Raw(
+				"SELECT count(*) FROM sqlite_master WHERE type = ? AND tbl_name = ? AND (sql LIKE ? OR sql LIKE ? OR sql LIKE ? OR sql LIKE ? OR sql LIKE ?)",
+				"table", stmt.Table, `%"`+name+`" %`, `%`+name+` %`, "%`"+name+"`%", "%["+name+"]%", "%\t"+name+"\t%",
+			).Row().Scan(&count)
+		}
+		return nil
+	})
+	return count > 0
+}
+
+func (m Migrator) AlterColumn(value interface{}, name string) error {
+	return m.RunWithoutForeignKey(func() error {
+		return m.recreateTable(value, nil, func(rawDDL string, stmt *gorm.Statement) (sql string, sqlArgs []interface{}, err error) {
+			if field := stmt.Schema.LookUpField(name); field != nil {
+				// lookup field from table definition, ddl might looks like `'name' int,` or `'name' int)`
+				reg, err := regexp.Compile("(`|'|\"| )" + field.DBName + "(`|'|\"| ) .*?(,|\\)\\s*$)")
+				if err != nil {
+					return "", nil, err
+				}
+
+				createSQL := reg.ReplaceAllString(rawDDL, fmt.Sprintf("`%v` ?$3", field.DBName))
+
+				if createSQL == rawDDL {
+					return "", nil, fmt.Errorf("failed to look up field %v from DDL %v", field.DBName, rawDDL)
+				}
+
+				return createSQL, []interface{}{m.FullDataTypeOf(field)}, nil
+			}
+			return "", nil, fmt.Errorf("failed to alter field with name %v", name)
+		})
+	})
+}
+
+// ColumnTypes return columnTypes []gorm.ColumnType and execErr error
+func (m Migrator) ColumnTypes(value interface{}) ([]gorm.ColumnType, error) {
+	columnTypes := make([]gorm.ColumnType, 0)
+	execErr := m.RunWithValue(value, func(stmt *gorm.Statement) (err error) {
+		var (
+			sqls   []string
+			sqlDDL *ddl
+		)
+
+		if err := m.DB.Raw("SELECT sql FROM sqlite_master WHERE type IN ? AND tbl_name = ? AND sql IS NOT NULL order by type = ? desc", []string{"table", "index"}, stmt.Table, "table").Scan(&sqls).Error; err != nil {
+			return err
+		}
+
+		if sqlDDL, err = parseDDL(sqls...); err != nil {
+			return err
+		}
+
+		rows, err := m.DB.Session(&gorm.Session{}).Table(stmt.Table).Limit(1).Rows()
+		if err != nil {
+			return err
+		}
+		defer func() {
+			err = rows.Close()
+		}()
+
+		var rawColumnTypes []*sql.ColumnType
+		rawColumnTypes, err = rows.ColumnTypes()
+		if err != nil {
+			return err
+		}
+
+		for _, c := range rawColumnTypes {
+			columnType := migrator.ColumnType{SQLColumnType: c}
+			for _, column := range sqlDDL.columns {
+				if column.NameValue.String == c.Name() {
+					column.SQLColumnType = c
+					columnType = column
+					break
+				}
+			}
+			columnTypes = append(columnTypes, columnType)
+		}
+
+		return err
+	})
+
+	return columnTypes, execErr
+}
+
+func (m Migrator) DropColumn(value interface{}, name string) error {
+	return m.recreateTable(value, nil, func(rawDDL string, stmt *gorm.Statement) (sql string, sqlArgs []interface{}, err error) {
+		if field := stmt.Schema.LookUpField(name); field != nil {
+			name = field.DBName
+		}
+
+		reg, err := regexp.Compile("(`|'|\"| |\\[)" + name + "(`|'|\"| |\\]) .*?,")
+		if err != nil {
+			return "", nil, err
+		}
+
+		createSQL := reg.ReplaceAllString(rawDDL, "")
+
+		return createSQL, nil, nil
+	})
+}
+
+func (m Migrator) CreateConstraint(value interface{}, name string) error {
+	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
+		constraint, chk, table := m.GuessConstraintAndTable(stmt, name)
+
+		return m.recreateTable(value, &table,
+			func(rawDDL string, stmt *gorm.Statement) (sql string, sqlArgs []interface{}, err error) {
+				var (
+					constraintName   string
+					constraintSql    string
+					constraintValues []interface{}
+				)
+
+				if constraint != nil {
+					constraintName = constraint.Name
+					constraintSql, constraintValues = buildConstraint(constraint)
+				} else if chk != nil {
+					constraintName = chk.Name
+					constraintSql = "CONSTRAINT ? CHECK (?)"
+					constraintValues = []interface{}{clause.Column{Name: chk.Name}, clause.Expr{SQL: chk.Constraint}}
+				} else {
+					return "", nil, nil
+				}
+
+				createDDL, err := parseDDL(rawDDL)
+				if err != nil {
+					return "", nil, err
+				}
+				createDDL.addConstraint(constraintName, constraintSql)
+				createSQL := createDDL.compile()
+
+				return createSQL, constraintValues, nil
+			})
+	})
+}
+
+func (m Migrator) DropConstraint(value interface{}, name string) error {
+	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
+		constraint, chk, table := m.GuessConstraintAndTable(stmt, name)
+		if constraint != nil {
+			name = constraint.Name
+		} else if chk != nil {
+			name = chk.Name
+		}
+
+		return m.recreateTable(value, &table,
+			func(rawDDL string, stmt *gorm.Statement) (sql string, sqlArgs []interface{}, err error) {
+				createDDL, err := parseDDL(rawDDL)
+				if err != nil {
+					return "", nil, err
+				}
+				createDDL.removeConstraint(name)
+				createSQL := createDDL.compile()
+
+				return createSQL, nil, nil
+			})
+	})
+}
+
+func (m Migrator) HasConstraint(value interface{}, name string) bool {
+	var count int64
+	m.RunWithValue(value, func(stmt *gorm.Statement) error {
+		constraint, chk, table := m.GuessConstraintAndTable(stmt, name)
+		if constraint != nil {
+			name = constraint.Name
+		} else if chk != nil {
+			name = chk.Name
+		}
+
+		m.DB.Raw(
+			"SELECT count(*) FROM sqlite_master WHERE type = ? AND tbl_name = ? AND (sql LIKE ? OR sql LIKE ? OR sql LIKE ? OR sql LIKE ? OR sql LIKE ?)",
+			"table", table, `%CONSTRAINT "`+name+`" %`, `%CONSTRAINT `+name+` %`, "%CONSTRAINT `"+name+"`%", "%CONSTRAINT ["+name+"]%", "%CONSTRAINT \t"+name+"\t%",
+		).Row().Scan(&count)
+
+		return nil
+	})
+
+	return count > 0
+}
+
+func (m Migrator) CurrentDatabase() (name string) {
+	var null interface{}
+	m.DB.Raw("PRAGMA database_list").Row().Scan(&null, &name, &null)
+	return
+}
+
+func (m Migrator) BuildIndexOptions(opts []schema.IndexOption, stmt *gorm.Statement) (results []interface{}) {
+	for _, opt := range opts {
+		str := stmt.Quote(opt.DBName)
+		if opt.Expression != "" {
+			str = opt.Expression
+		}
+
+		if opt.Collate != "" {
+			str += " COLLATE " + opt.Collate
+		}
+
+		if opt.Sort != "" {
+			str += " " + opt.Sort
+		}
+		results = append(results, clause.Expr{SQL: str})
+	}
+	return
+}
+
+func (m Migrator) CreateIndex(value interface{}, name string) error {
+	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
+		if stmt.Schema != nil {
+			if idx := stmt.Schema.LookIndex(name); idx != nil {
+				opts := m.BuildIndexOptions(idx.Fields, stmt)
+				values := []interface{}{clause.Column{Name: idx.Name}, clause.Table{Name: stmt.Table}, opts}
+
+				createIndexSQL := "CREATE "
+				if idx.Class != "" {
+					createIndexSQL += idx.Class + " "
+				}
+				createIndexSQL += "INDEX ?"
+
+				if idx.Type != "" {
+					createIndexSQL += " USING " + idx.Type
+				}
+				createIndexSQL += " ON ??"
+
+				if idx.Where != "" {
+					createIndexSQL += " WHERE " + idx.Where
+				}
+
+				return m.DB.Exec(createIndexSQL, values...).Error
+			}
+		}
+		return fmt.Errorf("failed to create index with name %v", name)
+	})
+}
+
+func (m Migrator) HasIndex(value interface{}, name string) bool {
+	var count int
+	m.RunWithValue(value, func(stmt *gorm.Statement) error {
+		if stmt.Schema != nil {
+			if idx := stmt.Schema.LookIndex(name); idx != nil {
+				name = idx.Name
+			}
+		}
+
+		if name != "" {
+			m.DB.Raw(
+				"SELECT count(*) FROM sqlite_master WHERE type = ? AND tbl_name = ? AND name = ?", "index", stmt.Table, name,
+			).Row().Scan(&count)
+		}
+		return nil
+	})
+	return count > 0
+}
+
+func (m Migrator) RenameIndex(value interface{}, oldName, newName string) error {
+	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
+		var sql string
+		m.DB.Raw("SELECT sql FROM sqlite_master WHERE type = ? AND tbl_name = ? AND name = ?", "index", stmt.Table, oldName).Row().Scan(&sql)
+		if sql != "" {
+			if err := m.DropIndex(value, oldName); err != nil {
+				return err
+			}
+			return m.DB.Exec(strings.Replace(sql, oldName, newName, 1)).Error
+		}
+		return fmt.Errorf("failed to find index with name %v", oldName)
+	})
+}
+
+func (m Migrator) DropIndex(value interface{}, name string) error {
+	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
+		if stmt.Schema != nil {
+			if idx := stmt.Schema.LookIndex(name); idx != nil {
+				name = idx.Name
+			}
+		}
+
+		return m.DB.Exec("DROP INDEX ?", clause.Column{Name: name}).Error
+	})
+}
+
+func buildConstraint(constraint *schema.Constraint) (sql string, results []interface{}) {
+	sql = "CONSTRAINT ? FOREIGN KEY ? REFERENCES ??"
+	if constraint.OnDelete != "" {
+		sql += " ON DELETE " + constraint.OnDelete
+	}
+
+	if constraint.OnUpdate != "" {
+		sql += " ON UPDATE " + constraint.OnUpdate
+	}
+
+	var foreignKeys, references []interface{}
+	for _, field := range constraint.ForeignKeys {
+		foreignKeys = append(foreignKeys, clause.Column{Name: field.DBName})
+	}
+
+	for _, field := range constraint.References {
+		references = append(references, clause.Column{Name: field.DBName})
+	}
+	results = append(results, clause.Table{Name: constraint.Name}, foreignKeys, clause.Table{Name: constraint.ReferenceSchema.Table}, references)
+	return
+}
+
+func (m Migrator) getRawDDL(table string) (string, error) {
+	var createSQL string
+	m.DB.Raw("SELECT sql FROM sqlite_master WHERE type = ? AND tbl_name = ? AND name = ?", "table", table, table).Row().Scan(&createSQL)
+
+	if m.DB.Error != nil {
+		return "", m.DB.Error
+	}
+	return createSQL, nil
+}
+
+func (m Migrator) recreateTable(value interface{}, tablePtr *string,
+	getCreateSQL func(rawDDL string, stmt *gorm.Statement) (sql string, sqlArgs []interface{}, err error)) error {
+	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
+		table := stmt.Table
+		if tablePtr != nil {
+			table = *tablePtr
+		}
+
+		rawDDL, err := m.getRawDDL(table)
+		if err != nil {
+			return err
+		}
+
+		newTableName := table + "__temp"
+
+		createSQL, sqlArgs, err := getCreateSQL(rawDDL, stmt)
+		if err != nil {
+			return err
+		}
+		if createSQL == "" {
+			return nil
+		}
+
+		tableReg, err := regexp.Compile("\\s*('|`|\")?\\b" + table + "\\b('|`|\")?\\s*")
+		if err != nil {
+			return err
+		}
+		createSQL = tableReg.ReplaceAllString(createSQL, fmt.Sprintf(" `%v` ", newTableName))
+
+		createDDL, err := parseDDL(createSQL)
+		if err != nil {
+			return err
+		}
+		columns := createDDL.getColumns()
+
+		return m.DB.Transaction(func(tx *gorm.DB) error {
+			if err := tx.Exec(createSQL, sqlArgs...).Error; err != nil {
+				return err
+			}
+
+			queries := []string{
+				fmt.Sprintf("INSERT INTO `%v`(%v) SELECT %v FROM `%v`", newTableName, strings.Join(columns, ","), strings.Join(columns, ","), table),
+				fmt.Sprintf("DROP TABLE `%v`", table),
+				fmt.Sprintf("ALTER TABLE `%v` RENAME TO `%v`", newTableName, table),
+			}
+			for _, query := range queries {
+				if err := tx.Exec(query).Error; err != nil {
+					return err
+				}
+			}
+			return nil
+		})
+	})
+}

gormlite/sqlite.go

@@ -0,0 +1,219 @@
+// Package gormlite provides a GORM driver for SQLite.
+package gormlite
+
+import (
+	"context"
+	"database/sql"
+	"strconv"
+	"strings"
+
+	"gorm.io/gorm"
+	"gorm.io/gorm/callbacks"
+	"gorm.io/gorm/clause"
+	"gorm.io/gorm/logger"
+	"gorm.io/gorm/migrator"
+	"gorm.io/gorm/schema"
+
+	_ "github.com/ncruces/go-sqlite3/driver"
+)
+
+type Dialector struct {
+	DSN  string
+	Conn gorm.ConnPool
+}
+
+func Open(dsn string) gorm.Dialector {
+	return &Dialector{DSN: dsn}
+}
+
+func (dialector Dialector) Name() string {
+	return "sqlite"
+}
+
+func (dialector Dialector) Initialize(db *gorm.DB) (err error) {
+	if dialector.Conn != nil {
+		db.ConnPool = dialector.Conn
+	} else {
+		conn, err := sql.Open("sqlite3", dialector.DSN)
+		if err != nil {
+			return err
+		}
+		db.ConnPool = conn
+	}
+
+	var version string
+	if err := db.ConnPool.QueryRowContext(context.Background(), "select sqlite_version()").Scan(&version); err != nil {
+		return err
+	}
+	// https://www.sqlite.org/releaselog/3_35_0.html
+	if compareVersion(version, "3.35.0") >= 0 {
+		callbacks.RegisterDefaultCallbacks(db, &callbacks.Config{
+			CreateClauses:        []string{"INSERT", "VALUES", "ON CONFLICT", "RETURNING"},
+			UpdateClauses:        []string{"UPDATE", "SET", "WHERE", "RETURNING"},
+			DeleteClauses:        []string{"DELETE", "FROM", "WHERE", "RETURNING"},
+			LastInsertIDReversed: true,
+		})
+	} else {
+		callbacks.RegisterDefaultCallbacks(db, &callbacks.Config{
+			LastInsertIDReversed: true,
+		})
+	}
+
+	for k, v := range dialector.ClauseBuilders() {
+		db.ClauseBuilders[k] = v
+	}
+	return
+}
+
+func (dialector Dialector) ClauseBuilders() map[string]clause.ClauseBuilder {
+	return map[string]clause.ClauseBuilder{
+		"INSERT": func(c clause.Clause, builder clause.Builder) {
+			if insert, ok := c.Expression.(clause.Insert); ok {
+				if stmt, ok := builder.(*gorm.Statement); ok {
+					stmt.WriteString("INSERT ")
+					if insert.Modifier != "" {
+						stmt.WriteString(insert.Modifier)
+						stmt.WriteByte(' ')
+					}
+
+					stmt.WriteString("INTO ")
+					if insert.Table.Name == "" {
+						stmt.WriteQuoted(stmt.Table)
+					} else {
+						stmt.WriteQuoted(insert.Table)
+					}
+					return
+				}
+			}
+
+			c.Build(builder)
+		},
+		"LIMIT": func(c clause.Clause, builder clause.Builder) {
+			if limit, ok := c.Expression.(clause.Limit); ok {
+				var lmt = -1
+				if limit.Limit != nil && *limit.Limit >= 0 {
+					lmt = *limit.Limit
+				}
+				if lmt >= 0 || limit.Offset > 0 {
+					builder.WriteString("LIMIT ")
+					builder.WriteString(strconv.Itoa(lmt))
+				}
+				if limit.Offset > 0 {
+					builder.WriteString(" OFFSET ")
+					builder.WriteString(strconv.Itoa(limit.Offset))
+				}
+			}
+		},
+		"FOR": func(c clause.Clause, builder clause.Builder) {
+			if _, ok := c.Expression.(clause.Locking); ok {
+				// SQLite3 does not support row-level locking.
+				return
+			}
+			c.Build(builder)
+		},
+	}
+}
+
+func (dialector Dialector) DefaultValueOf(field *schema.Field) clause.Expression {
+	if field.AutoIncrement {
+		return clause.Expr{SQL: "NULL"}
+	}
+
+	// doesn't work, will raise error
+	return clause.Expr{SQL: "DEFAULT"}
+}
+
+func (dialector Dialector) Migrator(db *gorm.DB) gorm.Migrator {
+	return Migrator{migrator.Migrator{Config: migrator.Config{
+		DB:                          db,
+		Dialector:                   dialector,
+		CreateIndexAfterCreateTable: true,
+	}}}
+}
+
+func (dialector Dialector) BindVarTo(writer clause.Writer, stmt *gorm.Statement, v interface{}) {
+	writer.WriteByte('?')
+}
+
+func (dialector Dialector) QuoteTo(writer clause.Writer, str string) {
+	writer.WriteByte('`')
+	if strings.Contains(str, ".") {
+		for idx, str := range strings.Split(str, ".") {
+			if idx > 0 {
+				writer.WriteString(".`")
+			}
+			writer.WriteString(str)
+			writer.WriteByte('`')
+		}
+	} else {
+		writer.WriteString(str)
+		writer.WriteByte('`')
+	}
+}
+
+func (dialector Dialector) Explain(sql string, vars ...interface{}) string {
+	return logger.ExplainSQL(sql, nil, `"`, vars...)
+}
+
+func (dialector Dialector) DataTypeOf(field *schema.Field) string {
+	switch field.DataType {
+	case schema.Bool:
+		return "numeric"
+	case schema.Int, schema.Uint:
+		if field.AutoIncrement && !field.PrimaryKey {
+			// https://www.sqlite.org/autoinc.html
+			return "integer PRIMARY KEY AUTOINCREMENT"
+		} else {
+			return "integer"
+		}
+	case schema.Float:
+		return "real"
+	case schema.String:
+		return "text"
+	case schema.Time:
+		// Distinguish between schema.Time and tag time
+		if val, ok := field.TagSettings["TYPE"]; ok {
+			return val
+		} else {
+			return "datetime"
+		}
+	case schema.Bytes:
+		return "blob"
+	}
+
+	return string(field.DataType)
+}
+
+func (dialectopr Dialector) SavePoint(tx *gorm.DB, name string) error {
+	tx.Exec("SAVEPOINT " + name)
+	return nil
+}
+
+func (dialectopr Dialector) RollbackTo(tx *gorm.DB, name string) error {
+	tx.Exec("ROLLBACK TO SAVEPOINT " + name)
+	return nil
+}
+
+func compareVersion(version1, version2 string) int {
+	n, m := len(version1), len(version2)
+	i, j := 0, 0
+	for i < n || j < m {
+		x := 0
+		for ; i < n && version1[i] != '.'; i++ {
+			x = x*10 + int(version1[i]-'0')
+		}
+		i++
+		y := 0
+		for ; j < m && version2[j] != '.'; j++ {
+			y = y*10 + int(version2[j]-'0')
+		}
+		j++
+		if x > y {
+			return 1
+		}
+		if x < y {
+			return -1
+		}
+	}
+	return 0
+}

gormlite/sqlite_test.go

@@ -0,0 +1,64 @@
+package gormlite
+
+import (
+	"fmt"
+	"testing"
+
+	"gorm.io/gorm"
+
+	_ "github.com/ncruces/go-sqlite3/embed"
+)
+
+func TestDialector(t *testing.T) {
+	// This is the DSN of the in-memory SQLite database for these tests.
+	const InMemoryDSN = "file:testdatabase?mode=memory&cache=shared"
+
+	rows := []struct {
+		description  string
+		dialector    *Dialector
+		openSuccess  bool
+		query        string
+		querySuccess bool
+	}{
+		{
+			description: "Default driver",
+			dialector: &Dialector{
+				DSN: InMemoryDSN,
+			},
+			openSuccess:  true,
+			query:        "SELECT 1",
+			querySuccess: true,
+		},
+	}
+	for rowIndex, row := range rows {
+		t.Run(fmt.Sprintf("%d/%s", rowIndex, row.description), func(t *testing.T) {
+			db, err := gorm.Open(row.dialector, &gorm.Config{})
+			if !row.openSuccess {
+				if err == nil {
+					t.Errorf("Expected Open to fail.")
+				}
+				return
+			}
+
+			if err != nil {
+				t.Errorf("Expected Open to succeed; got error: %v", err)
+			}
+			if db == nil {
+				t.Errorf("Expected db to be non-nil.")
+			}
+			if row.query != "" {
+				err = db.Exec(row.query).Error
+				if !row.querySuccess {
+					if err == nil {
+						t.Errorf("Expected query to fail.")
+					}
+					return
+				}
+
+				if err != nil {
+					t.Errorf("Expected query to succeed; got error: %v", err)
+				}
+			}
+		})
+	}
+}

gormlite/test.sh

@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+cd -P -- "$(dirname -- "$0")"
+
+rm -rf gorm/ tests/
+git clone --filter=blob:none --branch=v1.25.1 https://github.com/go-gorm/gorm.git
+mv gorm/tests tests
+rm -rf gorm/
+
+patch -p1 -N < tests.patch
+
+cd tests
+go mod tidy && go work use . && go test
+
+cd ..
+rm -rf tests/
+go work use -r .

gormlite/tests.patch

@@ -0,0 +1,63 @@
+diff --git a/tests/.gitignore b/tests/.gitignore
+index 08cb523..72e8ffc 100644
+--- a/tests/.gitignore
++++ b/tests/.gitignore
+@@ -1 +1 @@
+-go.sum
++*
+diff --git a/tests/go.mod b/tests/go.mod
+index f47d175..84b80c2 100644
+--- a/tests/go.mod
++++ b/tests/go.mod
+@@ -7,13 +7,13 @@ require (
+ 	github.com/jackc/pgx/v5 v5.3.1 // indirect
+ 	github.com/jinzhu/now v1.1.5
+ 	github.com/lib/pq v1.10.8
+-	github.com/mattn/go-sqlite3 v1.14.16 // indirect
++	github.com/ncruces/go-sqlite3 v0.7.2
++	github.com/ncruces/go-sqlite3/gormlite v0.0.0
+ 	golang.org/x/crypto v0.8.0 // indirect
+ 	gorm.io/driver/mysql v1.5.0
+ 	gorm.io/driver/postgres v1.5.0
+-	gorm.io/driver/sqlite v1.5.0
+ 	gorm.io/driver/sqlserver v1.4.3
+-	gorm.io/gorm v1.25.0
++	gorm.io/gorm v1.25.1
+ )
+ 
+-replace gorm.io/gorm => ../
++replace github.com/ncruces/go-sqlite3/gormlite => ../
+diff --git a/tests/scanner_valuer_test.go b/tests/scanner_valuer_test.go
+index 1412169..472434b 100644
+--- a/tests/scanner_valuer_test.go
++++ b/tests/scanner_valuer_test.go
+@@ -170,10 +170,10 @@ func (data *EncryptedData) Scan(value interface{}) error {
+ 			return errors.New("Too short")
+ 		}
+ 
+-		*data = b[3:]
++		*data = append((*data)[0:], b[3:]...)
+ 		return nil
+ 	} else if s, ok := value.(string); ok {
+-		*data = []byte(s)[3:]
++		*data = []byte(s[3:])
+ 		return nil
+ 	}
+ 
+diff --git a/tests/tests_test.go b/tests/tests_test.go
+index 90eb847..cd9af43 100644
+--- a/tests/tests_test.go
++++ b/tests/tests_test.go
+@@ -7,9 +7,11 @@ import (
+ 	"path/filepath"
+ 	"time"
+ 
++	_ "github.com/ncruces/go-sqlite3/embed"
++	sqlite "github.com/ncruces/go-sqlite3/gormlite"
++
+ 	"gorm.io/driver/mysql"
+ 	"gorm.io/driver/postgres"
+-	"gorm.io/driver/sqlite"
+ 	"gorm.io/driver/sqlserver"
+ 	"gorm.io/gorm"
+ 	"gorm.io/gorm/logger"

internal/util/bool.go

@@ -0,0 +1,22 @@
+package util
+
+import "strings"
+
+func ParseBool(s string) (b, ok bool) {
+	if len(s) == 0 {
+		return false, false
+	}
+	if s[0] == '0' {
+		return false, true
+	}
+	if '1' <= s[0] && s[0] <= '9' {
+		return true, true
+	}
+	switch strings.ToLower(s) {
+	case "true", "yes", "on":
+		return true, true
+	case "false", "no", "off":
+		return false, true
+	}
+	return false, false
+}

internal/util/bool_test.go

@@ -0,0 +1,28 @@
+package util
+
+import "testing"
+
+func TestParseBool(t *testing.T) {
+	tests := []struct {
+		str string
+		val bool
+		ok  bool
+	}{
+		{"", false, false},
+		{"0", false, true},
+		{"1", true, true},
+		{"9", true, true},
+		{"T", false, false},
+		{"true", true, true},
+		{"FALSE", false, true},
+		{"false?", false, false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.str, func(t *testing.T) {
+			gotVal, gotOK := ParseBool(tt.str)
+			if gotVal != tt.val || gotOK != tt.ok {
+				t.Errorf("ParseBool(%q) = (%v, %v) want (%v, %v)", tt.str, gotVal, gotOK, tt.val, tt.ok)
+			}
+		})
+	}
+}

internal/util/const.go

@@ -0,0 +1,116 @@
+package util
+
+// https://sqlite.com/matrix/rescode.html
+const (
+	OK = 0 /* Successful result */
+
+	ERROR      = 1  /* Generic error */
+	INTERNAL   = 2  /* Internal logic error in SQLite */
+	PERM       = 3  /* Access permission denied */
+	ABORT      = 4  /* Callback routine requested an abort */
+	BUSY       = 5  /* The database file is locked */
+	LOCKED     = 6  /* A table in the database is locked */
+	NOMEM      = 7  /* A malloc() failed */
+	READONLY   = 8  /* Attempt to write a readonly database */
+	INTERRUPT  = 9  /* Operation terminated by sqlite3_interrupt() */
+	IOERR      = 10 /* Some kind of disk I/O error occurred */
+	CORRUPT    = 11 /* The database disk image is malformed */
+	NOTFOUND   = 12 /* Unknown opcode in sqlite3_file_control() */
+	FULL       = 13 /* Insertion failed because database is full */
+	CANTOPEN   = 14 /* Unable to open the database file */
+	PROTOCOL   = 15 /* Database lock protocol error */
+	EMPTY      = 16 /* Internal use only */
+	SCHEMA     = 17 /* The database schema changed */
+	TOOBIG     = 18 /* String or BLOB exceeds size limit */
+	CONSTRAINT = 19 /* Abort due to constraint violation */
+	MISMATCH   = 20 /* Data type mismatch */
+	MISUSE     = 21 /* Library used incorrectly */
+	NOLFS      = 22 /* Uses OS features not supported on host */
+	AUTH       = 23 /* Authorization denied */
+	FORMAT     = 24 /* Not used */
+	RANGE      = 25 /* 2nd parameter to sqlite3_bind out of range */
+	NOTADB     = 26 /* File opened that is not a database file */
+	NOTICE     = 27 /* Notifications from sqlite3_log() */
+	WARNING    = 28 /* Warnings from sqlite3_log() */
+
+	ROW  = 100 /* sqlite3_step() has another row ready */
+	DONE = 101 /* sqlite3_step() has finished executing */
+
+	ERROR_MISSING_COLLSEQ   = ERROR | (1 << 8)
+	ERROR_RETRY             = ERROR | (2 << 8)
+	ERROR_SNAPSHOT          = ERROR | (3 << 8)
+	IOERR_READ              = IOERR | (1 << 8)
+	IOERR_SHORT_READ        = IOERR | (2 << 8)
+	IOERR_WRITE             = IOERR | (3 << 8)
+	IOERR_FSYNC             = IOERR | (4 << 8)
+	IOERR_DIR_FSYNC         = IOERR | (5 << 8)
+	IOERR_TRUNCATE          = IOERR | (6 << 8)
+	IOERR_FSTAT             = IOERR | (7 << 8)
+	IOERR_UNLOCK            = IOERR | (8 << 8)
+	IOERR_RDLOCK            = IOERR | (9 << 8)
+	IOERR_DELETE            = IOERR | (10 << 8)
+	IOERR_BLOCKED           = IOERR | (11 << 8)
+	IOERR_NOMEM             = IOERR | (12 << 8)
+	IOERR_ACCESS            = IOERR | (13 << 8)
+	IOERR_CHECKRESERVEDLOCK = IOERR | (14 << 8)
+	IOERR_LOCK              = IOERR | (15 << 8)
+	IOERR_CLOSE             = IOERR | (16 << 8)
+	IOERR_DIR_CLOSE         = IOERR | (17 << 8)
+	IOERR_SHMOPEN           = IOERR | (18 << 8)
+	IOERR_SHMSIZE           = IOERR | (19 << 8)
+	IOERR_SHMLOCK           = IOERR | (20 << 8)
+	IOERR_SHMMAP            = IOERR | (21 << 8)
+	IOERR_SEEK              = IOERR | (22 << 8)
+	IOERR_DELETE_NOENT      = IOERR | (23 << 8)
+	IOERR_MMAP              = IOERR | (24 << 8)
+	IOERR_GETTEMPPATH       = IOERR | (25 << 8)
+	IOERR_CONVPATH          = IOERR | (26 << 8)
+	IOERR_VNODE             = IOERR | (27 << 8)
+	IOERR_AUTH              = IOERR | (28 << 8)
+	IOERR_BEGIN_ATOMIC      = IOERR | (29 << 8)
+	IOERR_COMMIT_ATOMIC     = IOERR | (30 << 8)
+	IOERR_ROLLBACK_ATOMIC   = IOERR | (31 << 8)
+	IOERR_DATA              = IOERR | (32 << 8)
+	IOERR_CORRUPTFS         = IOERR | (33 << 8)
+	LOCKED_SHAREDCACHE      = LOCKED | (1 << 8)
+	LOCKED_VTAB             = LOCKED | (2 << 8)
+	BUSY_RECOVERY           = BUSY | (1 << 8)
+	BUSY_SNAPSHOT           = BUSY | (2 << 8)
+	BUSY_TIMEOUT            = BUSY | (3 << 8)
+	CANTOPEN_NOTEMPDIR      = CANTOPEN | (1 << 8)
+	CANTOPEN_ISDIR          = CANTOPEN | (2 << 8)
+	CANTOPEN_FULLPATH       = CANTOPEN | (3 << 8)
+	CANTOPEN_CONVPATH       = CANTOPEN | (4 << 8)
+	CANTOPEN_DIRTYWAL       = CANTOPEN | (5 << 8) /* Not Used */
+	CANTOPEN_SYMLINK        = CANTOPEN | (6 << 8)
+	CORRUPT_VTAB            = CORRUPT | (1 << 8)
+	CORRUPT_SEQUENCE        = CORRUPT | (2 << 8)
+	CORRUPT_INDEX           = CORRUPT | (3 << 8)
+	READONLY_RECOVERY       = READONLY | (1 << 8)
+	READONLY_CANTLOCK       = READONLY | (2 << 8)
+	READONLY_ROLLBACK       = READONLY | (3 << 8)
+	READONLY_DBMOVED        = READONLY | (4 << 8)
+	READONLY_CANTINIT       = READONLY | (5 << 8)
+	READONLY_DIRECTORY      = READONLY | (6 << 8)
+	ABORT_ROLLBACK          = ABORT | (2 << 8)
+	CONSTRAINT_CHECK        = CONSTRAINT | (1 << 8)
+	CONSTRAINT_COMMITHOOK   = CONSTRAINT | (2 << 8)
+	CONSTRAINT_FOREIGNKEY   = CONSTRAINT | (3 << 8)
+	CONSTRAINT_FUNCTION     = CONSTRAINT | (4 << 8)
+	CONSTRAINT_NOTNULL      = CONSTRAINT | (5 << 8)
+	CONSTRAINT_PRIMARYKEY   = CONSTRAINT | (6 << 8)
+	CONSTRAINT_TRIGGER      = CONSTRAINT | (7 << 8)
+	CONSTRAINT_UNIQUE       = CONSTRAINT | (8 << 8)
+	CONSTRAINT_VTAB         = CONSTRAINT | (9 << 8)
+	CONSTRAINT_ROWID        = CONSTRAINT | (10 << 8)
+	CONSTRAINT_PINNED       = CONSTRAINT | (11 << 8)
+	CONSTRAINT_DATATYPE     = CONSTRAINT | (12 << 8)
+	NOTICE_RECOVER_WAL      = NOTICE | (1 << 8)
+	NOTICE_RECOVER_ROLLBACK = NOTICE | (2 << 8)
+	NOTICE_RBU              = NOTICE | (3 << 8)
+	WARNING_AUTOINDEX       = WARNING | (1 << 8)
+	AUTH_USER               = AUTH | (1 << 8)
+
+	OK_LOAD_PERMANENTLY = OK | (1 << 8)
+	OK_SYMLINK          = OK | (2 << 8) /* internal use only */
+)

internal/util/error.go

@@ -0,0 +1,115 @@
+package util
+
+import (
+	"fmt"
+	"runtime"
+	"strconv"
+)
+
+type ErrorString string
+
+func (e ErrorString) Error() string { return string(e) }
+
+const (
+	NilErr       = ErrorString("sqlite3: invalid memory address or null pointer dereference")
+	OOMErr       = ErrorString("sqlite3: out of memory")
+	RangeErr     = ErrorString("sqlite3: index out of range")
+	NoNulErr     = ErrorString("sqlite3: missing NUL terminator")
+	NoGlobalErr  = ErrorString("sqlite3: could not find global: ")
+	NoFuncErr    = ErrorString("sqlite3: could not find function: ")
+	BinaryErr    = ErrorString("sqlite3: no SQLite binary embed/set/loaded")
+	TimeErr      = ErrorString("sqlite3: invalid time value")
+	WhenceErr    = ErrorString("sqlite3: invalid whence")
+	OffsetErr    = ErrorString("sqlite3: invalid offset")
+	TailErr      = ErrorString("sqlite3: multiple statements")
+	IsolationErr = ErrorString("sqlite3: unsupported isolation level")
+	NoVFSErr     = ErrorString("sqlite3: no such vfs: ")
+)
+
+func AssertErr() ErrorString {
+	msg := "sqlite3: assertion failed"
+	if _, file, line, ok := runtime.Caller(1); ok {
+		msg += " (" + file + ":" + strconv.Itoa(line) + ")"
+	}
+	return ErrorString(msg)
+}
+
+func Finalizer[T any](skip int) func(*T) {
+	msg := fmt.Sprintf("sqlite3: %T not closed", new(T))
+	if _, file, line, ok := runtime.Caller(skip + 1); ok && skip >= 0 {
+		msg += " (" + file + ":" + strconv.Itoa(line) + ")"
+	}
+	return func(*T) { panic(ErrorString(msg)) }
+}
+
+func ErrorCodeString(rc uint32) string {
+	switch rc {
+	case ABORT_ROLLBACK:
+		return "sqlite3: abort due to ROLLBACK"
+	case ROW:
+		return "sqlite3: another row available"
+	case DONE:
+		return "sqlite3: no more rows available"
+	}
+	switch rc & 0xff {
+	case OK:
+		return "sqlite3: not an error"
+	case ERROR:
+		return "sqlite3: SQL logic error"
+	case INTERNAL:
+		break
+	case PERM:
+		return "sqlite3: access permission denied"
+	case ABORT:
+		return "sqlite3: query aborted"
+	case BUSY:
+		return "sqlite3: database is locked"
+	case LOCKED:
+		return "sqlite3: database table is locked"
+	case NOMEM:
+		return "sqlite3: out of memory"
+	case READONLY:
+		return "sqlite3: attempt to write a readonly database"
+	case INTERRUPT:
+		return "sqlite3: interrupted"
+	case IOERR:
+		return "sqlite3: disk I/O error"
+	case CORRUPT:
+		return "sqlite3: database disk image is malformed"
+	case NOTFOUND:
+		return "sqlite3: unknown operation"
+	case FULL:
+		return "sqlite3: database or disk is full"
+	case CANTOPEN:
+		return "sqlite3: unable to open database file"
+	case PROTOCOL:
+		return "sqlite3: locking protocol"
+	case FORMAT:
+		break
+	case SCHEMA:
+		return "sqlite3: database schema has changed"
+	case TOOBIG:
+		return "sqlite3: string or blob too big"
+	case CONSTRAINT:
+		return "sqlite3: constraint failed"
+	case MISMATCH:
+		return "sqlite3: datatype mismatch"
+	case MISUSE:
+		return "sqlite3: bad parameter or other API misuse"
+	case NOLFS:
+		break
+	case AUTH:
+		return "sqlite3: authorization denied"
+	case EMPTY:
+		break
+	case RANGE:
+		return "sqlite3: column index out of range"
+	case NOTADB:
+		return "sqlite3: file is not a database"
+	case NOTICE:
+		return "sqlite3: notification message"
+	case WARNING:
+		return "sqlite3: warning message"
+	}
+	return "sqlite3: unknown error"
+}

internal/util/func.go

@@ -0,0 +1,102 @@
+package util
+
+import (
+	"context"
+
+	"github.com/tetratelabs/wazero"
+	"github.com/tetratelabs/wazero/api"
+)
+
+type i32 interface{ ~int32 | ~uint32 }
+type i64 interface{ ~int64 | ~uint64 }
+
+type funcII[TR, T0 i32] func(context.Context, api.Module, T0) TR
+
+func (fn funcII[TR, T0]) Call(ctx context.Context, mod api.Module, stack []uint64) {
+	stack[0] = uint64(fn(ctx, mod, T0(stack[0])))
+}
+
+func ExportFuncII[TR, T0 i32](mod wazero.HostModuleBuilder, name string, fn func(context.Context, api.Module, T0) TR) {
+	mod.NewFunctionBuilder().
+		WithGoModuleFunction(funcII[TR, T0](fn),
+			[]api.ValueType{api.ValueTypeI32}, []api.ValueType{api.ValueTypeI32}).
+		Export(name)
+}
+
+type funcIII[TR, T0, T1 i32] func(context.Context, api.Module, T0, T1) TR
+
+func (fn funcIII[TR, T0, T1]) Call(ctx context.Context, mod api.Module, stack []uint64) {
+	stack[0] = uint64(fn(ctx, mod, T0(stack[0]), T1(stack[1])))
+}
+
+func ExportFuncIII[TR, T0, T1 i32](mod wazero.HostModuleBuilder, name string, fn func(context.Context, api.Module, T0, T1) TR) {
+	mod.NewFunctionBuilder().
+		WithGoModuleFunction(funcIII[TR, T0, T1](fn),
+			[]api.ValueType{api.ValueTypeI32, api.ValueTypeI32}, []api.ValueType{api.ValueTypeI32}).
+		Export(name)
+}
+
+type funcIIII[TR, T0, T1, T2 i32] func(context.Context, api.Module, T0, T1, T2) TR
+
+func (fn funcIIII[TR, T0, T1, T2]) Call(ctx context.Context, mod api.Module, stack []uint64) {
+	stack[0] = uint64(fn(ctx, mod, T0(stack[0]), T1(stack[1]), T2(stack[2])))
+}
+
+func ExportFuncIIII[TR, T0, T1, T2 i32](mod wazero.HostModuleBuilder, name string, fn func(context.Context, api.Module, T0, T1, T2) TR) {
+	mod.NewFunctionBuilder().
+		WithGoModuleFunction(funcIIII[TR, T0, T1, T2](fn),
+			[]api.ValueType{api.ValueTypeI32, api.ValueTypeI32, api.ValueTypeI32}, []api.ValueType{api.ValueTypeI32}).
+		Export(name)
+}
+
+type funcIIIII[TR, T0, T1, T2, T3 i32] func(context.Context, api.Module, T0, T1, T2, T3) TR
+
+func (fn funcIIIII[TR, T0, T1, T2, T3]) Call(ctx context.Context, mod api.Module, stack []uint64) {
+	stack[0] = uint64(fn(ctx, mod, T0(stack[0]), T1(stack[1]), T2(stack[2]), T3(stack[3])))
+}
+
+func ExportFuncIIIII[TR, T0, T1, T2, T3 i32](mod wazero.HostModuleBuilder, name string, fn func(context.Context, api.Module, T0, T1, T2, T3) TR) {
+	mod.NewFunctionBuilder().
+		WithGoModuleFunction(funcIIIII[TR, T0, T1, T2, T3](fn),
+			[]api.ValueType{api.ValueTypeI32, api.ValueTypeI32, api.ValueTypeI32, api.ValueTypeI32}, []api.ValueType{api.ValueTypeI32}).
+		Export(name)
+}
+
+type funcIIIIII[TR, T0, T1, T2, T3, T4 i32] func(context.Context, api.Module, T0, T1, T2, T3, T4) TR
+
+func (fn funcIIIIII[TR, T0, T1, T2, T3, T4]) Call(ctx context.Context, mod api.Module, stack []uint64) {
+	stack[0] = uint64(fn(ctx, mod, T0(stack[0]), T1(stack[1]), T2(stack[2]), T3(stack[3]), T4(stack[4])))
+}
+
+func ExportFuncIIIIII[TR, T0, T1, T2, T3, T4 i32](mod wazero.HostModuleBuilder, name string, fn func(context.Context, api.Module, T0, T1, T2, T3, T4) TR) {
+	mod.NewFunctionBuilder().
+		WithGoModuleFunction(funcIIIIII[TR, T0, T1, T2, T3, T4](fn),
+			[]api.ValueType{api.ValueTypeI32, api.ValueTypeI32, api.ValueTypeI32, api.ValueTypeI32, api.ValueTypeI32}, []api.ValueType{api.ValueTypeI32}).
+		Export(name)
+}
+
+type funcIIIIJ[TR, T0, T1, T2 i32, T3 i64] func(context.Context, api.Module, T0, T1, T2, T3) TR
+
+func (fn funcIIIIJ[TR, T0, T1, T2, T3]) Call(ctx context.Context, mod api.Module, stack []uint64) {
+	stack[0] = uint64(fn(ctx, mod, T0(stack[0]), T1(stack[1]), T2(stack[2]), T3(stack[3])))
+}
+
+func ExportFuncIIIIJ[TR, T0, T1, T2 i32, T3 i64](mod wazero.HostModuleBuilder, name string, fn func(context.Context, api.Module, T0, T1, T2, T3) TR) {
+	mod.NewFunctionBuilder().
+		WithGoModuleFunction(funcIIIIJ[TR, T0, T1, T2, T3](fn),
+			[]api.ValueType{api.ValueTypeI32, api.ValueTypeI32, api.ValueTypeI32, api.ValueTypeI64}, []api.ValueType{api.ValueTypeI32}).
+		Export(name)
+}
+
+type funcIIJ[TR, T0 i32, T1 i64] func(context.Context, api.Module, T0, T1) TR
+
+func (fn funcIIJ[TR, T0, T1]) Call(ctx context.Context, mod api.Module, stack []uint64) {
+	stack[0] = uint64(fn(ctx, mod, T0(stack[0]), T1(stack[1])))
+}
+
+func ExportFuncIIJ[TR, T0 i32, T1 i64](mod wazero.HostModuleBuilder, name string, fn func(context.Context, api.Module, T0, T1) TR) {
+	mod.NewFunctionBuilder().
+		WithGoModuleFunction(funcIIJ[TR, T0, T1](fn),
+			[]api.ValueType{api.ValueTypeI32, api.ValueTypeI64}, []api.ValueType{api.ValueTypeI32}).
+		Export(name)
+}

internal/util/mem.go

@@ -0,0 +1,110 @@
+package util
+
+import (
+	"bytes"
+	"math"
+
+	"github.com/tetratelabs/wazero/api"
+)
+
+func View(mod api.Module, ptr uint32, size uint64) []byte {
+	if ptr == 0 {
+		panic(NilErr)
+	}
+	if size > math.MaxUint32 {
+		panic(RangeErr)
+	}
+	buf, ok := mod.Memory().Read(ptr, uint32(size))
+	if !ok {
+		panic(RangeErr)
+	}
+	return buf
+}
+
+func ReadUint32(mod api.Module, ptr uint32) uint32 {
+	if ptr == 0 {
+		panic(NilErr)
+	}
+	v, ok := mod.Memory().ReadUint32Le(ptr)
+	if !ok {
+		panic(RangeErr)
+	}
+	return v
+}
+
+func WriteUint32(mod api.Module, ptr uint32, v uint32) {
+	if ptr == 0 {
+		panic(NilErr)
+	}
+	ok := mod.Memory().WriteUint32Le(ptr, v)
+	if !ok {
+		panic(RangeErr)
+	}
+}
+
+func ReadUint64(mod api.Module, ptr uint32) uint64 {
+	if ptr == 0 {
+		panic(NilErr)
+	}
+	v, ok := mod.Memory().ReadUint64Le(ptr)
+	if !ok {
+		panic(RangeErr)
+	}
+	return v
+}
+
+func WriteUint64(mod api.Module, ptr uint32, v uint64) {
+	if ptr == 0 {
+		panic(NilErr)
+	}
+	ok := mod.Memory().WriteUint64Le(ptr, v)
+	if !ok {
+		panic(RangeErr)
+	}
+}
+
+func ReadFloat64(mod api.Module, ptr uint32) float64 {
+	return math.Float64frombits(ReadUint64(mod, ptr))
+}
+
+func WriteFloat64(mod api.Module, ptr uint32, v float64) {
+	WriteUint64(mod, ptr, math.Float64bits(v))
+}
+
+func ReadString(mod api.Module, ptr, maxlen uint32) string {
+	if ptr == 0 {
+		panic(NilErr)
+	}
+	switch maxlen {
+	case 0:
+		return ""
+	case math.MaxUint32:
+		// avoid overflow
+	default:
+		maxlen = maxlen + 1
+	}
+	mem := mod.Memory()
+	buf, ok := mem.Read(ptr, maxlen)
+	if !ok {
+		buf, ok = mem.Read(ptr, mem.Size()-ptr)
+		if !ok {
+			panic(RangeErr)
+		}
+	}
+	if i := bytes.IndexByte(buf, 0); i < 0 {
+		panic(NoNulErr)
+	} else {
+		return string(buf[:i])
+	}
+}
+
+func WriteBytes(mod api.Module, ptr uint32, b []byte) {
+	buf := View(mod, ptr, uint64(len(b)))
+	copy(buf, b)
+}
+
+func WriteString(mod api.Module, ptr uint32, s string) {
+	buf := View(mod, ptr, uint64(len(s)+1))
+	buf[len(s)] = 0
+	copy(buf, s)
+}

internal/util/mem_test.go

@@ -0,0 +1,92 @@
+package util
+
+import (
+	"math"
+	"testing"
+
+	"github.com/tetratelabs/wazero/experimental/wazerotest"
+)
+
+func TestView_nil(t *testing.T) {
+	defer func() { _ = recover() }()
+	mock := wazerotest.NewModule(wazerotest.NewFixedMemory(wazerotest.PageSize))
+	View(mock, 0, 8)
+	t.Error("want panic")
+}
+
+func TestView_range(t *testing.T) {
+	defer func() { _ = recover() }()
+	mock := wazerotest.NewModule(wazerotest.NewFixedMemory(wazerotest.PageSize))
+	View(mock, wazerotest.PageSize-2, 8)
+	t.Error("want panic")
+}
+
+func TestView_overflow(t *testing.T) {
+	defer func() { _ = recover() }()
+	mock := wazerotest.NewModule(wazerotest.NewFixedMemory(wazerotest.PageSize))
+	View(mock, 1, math.MaxInt64)
+	t.Error("want panic")
+}
+
+func TestReadUint32_nil(t *testing.T) {
+	defer func() { _ = recover() }()
+	mock := wazerotest.NewModule(wazerotest.NewFixedMemory(wazerotest.PageSize))
+	ReadUint32(mock, 0)
+	t.Error("want panic")
+}
+
+func TestReadUint32_range(t *testing.T) {
+	defer func() { _ = recover() }()
+	mock := wazerotest.NewModule(wazerotest.NewFixedMemory(wazerotest.PageSize))
+	ReadUint32(mock, wazerotest.PageSize-2)
+	t.Error("want panic")
+}
+
+func TestReadUint64_nil(t *testing.T) {
+	defer func() { _ = recover() }()
+	mock := wazerotest.NewModule(wazerotest.NewFixedMemory(wazerotest.PageSize))
+	ReadUint64(mock, 0)
+	t.Error("want panic")
+}
+
+func TestReadUint64_range(t *testing.T) {
+	defer func() { _ = recover() }()
+	mock := wazerotest.NewModule(wazerotest.NewFixedMemory(wazerotest.PageSize))
+	ReadUint64(mock, wazerotest.PageSize-2)
+	t.Error("want panic")
+}
+
+func TestWriteUint32_nil(t *testing.T) {
+	defer func() { _ = recover() }()
+	mock := wazerotest.NewModule(wazerotest.NewFixedMemory(wazerotest.PageSize))
+	WriteUint32(mock, 0, 1)
+	t.Error("want panic")
+}
+
+func TestWriteUint32_range(t *testing.T) {
+	defer func() { _ = recover() }()
+	mock := wazerotest.NewModule(wazerotest.NewFixedMemory(wazerotest.PageSize))
+	WriteUint32(mock, wazerotest.PageSize-2, 1)
+	t.Error("want panic")
+}
+
+func TestWriteUint64_nil(t *testing.T) {
+	defer func() { _ = recover() }()
+	mock := wazerotest.NewModule(wazerotest.NewFixedMemory(wazerotest.PageSize))
+	WriteUint64(mock, 0, 1)
+	t.Error("want panic")
+}
+
+func TestWriteUint64_range(t *testing.T) {
+	defer func() { _ = recover() }()
+	mock := wazerotest.NewModule(wazerotest.NewFixedMemory(wazerotest.PageSize))
+	WriteUint64(mock, wazerotest.PageSize-2, 1)
+	t.Error("want panic")
+}
+
+func TestReadString_range(t *testing.T) {
+	defer func() { _ = recover() }()
+	mock := wazerotest.NewModule(wazerotest.NewFixedMemory(wazerotest.PageSize))
+	ReadString(mock, wazerotest.PageSize+2, math.MaxUint32)
+	t.Error("want panic")
+}

mem.go

@@ -1,114 +0,0 @@
-package sqlite3
-
-import (
-	"bytes"
-	"math"
-
-	"github.com/tetratelabs/wazero/api"
-)
-
-type memory struct {
-	mod api.Module
-}
-
-func (m memory) view(ptr uint32, size uint64) []byte {
-	if ptr == 0 {
-		panic(nilErr)
-	}
-	if size > math.MaxUint32 {
-		panic(rangeErr)
-	}
-	buf, ok := m.mod.Memory().Read(ptr, uint32(size))
-	if !ok {
-		panic(rangeErr)
-	}
-	return buf
-}
-
-func (m memory) readUint32(ptr uint32) uint32 {
-	if ptr == 0 {
-		panic(nilErr)
-	}
-	v, ok := m.mod.Memory().ReadUint32Le(ptr)
-	if !ok {
-		panic(rangeErr)
-	}
-	return v
-}
-
-func (m memory) writeUint32(ptr, v uint32) {
-	if ptr == 0 {
-		panic(nilErr)
-	}
-	ok := m.mod.Memory().WriteUint32Le(ptr, v)
-	if !ok {
-		panic(rangeErr)
-	}
-}
-
-func (m memory) readUint64(ptr uint32) uint64 {
-	if ptr == 0 {
-		panic(nilErr)
-	}
-	v, ok := m.mod.Memory().ReadUint64Le(ptr)
-	if !ok {
-		panic(rangeErr)
-	}
-	return v
-}
-
-func (m memory) writeUint64(ptr uint32, v uint64) {
-	if ptr == 0 {
-		panic(nilErr)
-	}
-	ok := m.mod.Memory().WriteUint64Le(ptr, v)
-	if !ok {
-		panic(rangeErr)
-	}
-}
-
-func (m memory) readFloat64(ptr uint32) float64 {
-	return math.Float64frombits(m.readUint64(ptr))
-}
-
-func (m memory) writeFloat64(ptr uint32, v float64) {
-	m.writeUint64(ptr, math.Float64bits(v))
-}
-
-func (m memory) readString(ptr, maxlen uint32) string {
-	if ptr == 0 {
-		panic(nilErr)
-	}
-	switch maxlen {
-	case 0:
-		return ""
-	case math.MaxUint32:
-		// avoid overflow
-	default:
-		maxlen = maxlen + 1
-	}
-	mem := m.mod.Memory()
-	buf, ok := mem.Read(ptr, maxlen)
-	if !ok {
-		buf, ok = mem.Read(ptr, mem.Size()-ptr)
-		if !ok {
-			panic(rangeErr)
-		}
-	}
-	if i := bytes.IndexByte(buf, 0); i < 0 {
-		panic(noNulErr)
-	} else {
-		return string(buf[:i])
-	}
-}
-
-func (m memory) writeBytes(ptr uint32, b []byte) {
-	buf := m.view(ptr, uint64(len(b)))
-	copy(buf, b)
-}
-
-func (m memory) writeString(ptr uint32, s string) {
-	buf := m.view(ptr, uint64(len(s)+1))
-	buf[len(s)] = 0
-	copy(buf, s)
-}

mem_test.go

@@ -1,90 +0,0 @@
-package sqlite3
-
-import (
-	"math"
-	"testing"
-)
-
-func Test_memory_view_nil(t *testing.T) {
-	defer func() { _ = recover() }()
-	mem := newMemory(128)
-	mem.view(0, 8)
-	t.Error("want panic")
-}
-
-func Test_memory_view_range(t *testing.T) {
-	defer func() { _ = recover() }()
-	mem := newMemory(128)
-	mem.view(126, 8)
-	t.Error("want panic")
-}
-
-func Test_memory_view_overflow(t *testing.T) {
-	defer func() { _ = recover() }()
-	mem := newMemory(128)
-	mem.view(1, math.MaxInt64)
-	t.Error("want panic")
-}
-
-func Test_memory_readUint32_nil(t *testing.T) {
-	defer func() { _ = recover() }()
-	mem := newMemory(128)
-	mem.readUint32(0)
-	t.Error("want panic")
-}
-
-func Test_memory_readUint32_range(t *testing.T) {
-	defer func() { _ = recover() }()
-	mem := newMemory(128)
-	mem.readUint32(126)
-	t.Error("want panic")
-}
-
-func Test_memory_readUint64_nil(t *testing.T) {
-	defer func() { _ = recover() }()
-	mem := newMemory(128)
-	mem.readUint64(0)
-	t.Error("want panic")
-}
-
-func Test_memory_readUint64_range(t *testing.T) {
-	defer func() { _ = recover() }()
-	mem := newMemory(128)
-	mem.readUint64(126)
-	t.Error("want panic")
-}
-
-func Test_memory_writeUint32_nil(t *testing.T) {
-	defer func() { _ = recover() }()
-	mem := newMemory(128)
-	mem.writeUint32(0, 1)
-	t.Error("want panic")
-}
-
-func Test_memory_writeUint32_range(t *testing.T) {
-	defer func() { _ = recover() }()
-	mem := newMemory(128)
-	mem.writeUint32(126, 1)
-	t.Error("want panic")
-}
-
-func Test_memory_writeUint64_nil(t *testing.T) {
-	defer func() { _ = recover() }()
-	mem := newMemory(128)
-	mem.writeUint64(0, 1)
-	t.Error("want panic")
-}
-
-func Test_memory_writeUint64_range(t *testing.T) {
-	defer func() { _ = recover() }()
-	mem := newMemory(128)
-	mem.writeUint64(126, 1)
-	t.Error("want panic")
-}
-
-func Test_memory_readString_range(t *testing.T) {
-	defer func() { _ = recover() }()
-	mem := newMemory(128)
-	mem.readString(130, math.MaxUint32)
-	t.Error("want panic")
-}

mock_test.go

@@ -1,161 +0,0 @@
-package sqlite3
-
-import (
-	"context"
-	"encoding/binary"
-	"math"
-
-	"github.com/tetratelabs/wazero/api"
-)
-
-func init() {
-	Path = "./embed/sqlite3.wasm"
-}
-
-func newMemory(size uint32) memory {
-	mem := make(mockMemory, size)
-	return memory{mockModule{&mem}}
-}
-
-type mockModule struct {
-	memory api.Memory
-}
-
-func (m mockModule) Memory() api.Memory { return m.memory }
-func (m mockModule) String() string     { return "mockModule" }
-func (m mockModule) Name() string       { return "mockModule" }
-
-func (m mockModule) ExportedGlobal(name string) api.Global                          { return nil }
-func (m mockModule) ExportedMemory(name string) api.Memory                          { return nil }
-func (m mockModule) ExportedFunction(name string) api.Function                      { return nil }
-func (m mockModule) ExportedMemoryDefinitions() map[string]api.MemoryDefinition     { return nil }
-func (m mockModule) ExportedFunctionDefinitions() map[string]api.FunctionDefinition { return nil }
-func (m mockModule) CloseWithExitCode(ctx context.Context, exitCode uint32) error   { return nil }
-func (m mockModule) Close(context.Context) error                                    { return nil }
-
-type mockMemory []byte
-
-func (m mockMemory) Definition() api.MemoryDefinition { return nil }
-
-func (m mockMemory) Size() uint32 { return uint32(len(m)) }
-
-func (m mockMemory) ReadByte(offset uint32) (byte, bool) {
-	if offset >= m.Size() {
-		return 0, false
-	}
-	return m[offset], true
-}
-
-func (m mockMemory) ReadUint16Le(offset uint32) (uint16, bool) {
-	if !m.hasSize(offset, 2) {
-		return 0, false
-	}
-	return binary.LittleEndian.Uint16(m[offset : offset+2]), true
-}
-
-func (m mockMemory) ReadUint32Le(offset uint32) (uint32, bool) {
-	if !m.hasSize(offset, 4) {
-		return 0, false
-	}
-	return binary.LittleEndian.Uint32(m[offset : offset+4]), true
-}
-
-func (m mockMemory) ReadFloat32Le(offset uint32) (float32, bool) {
-	v, ok := m.ReadUint32Le(offset)
-	if !ok {
-		return 0, false
-	}
-	return math.Float32frombits(v), true
-}
-
-func (m mockMemory) ReadUint64Le(offset uint32) (uint64, bool) {
-	if !m.hasSize(offset, 8) {
-		return 0, false
-	}
-	return binary.LittleEndian.Uint64(m[offset : offset+8]), true
-}
-
-func (m mockMemory) ReadFloat64Le(offset uint32) (float64, bool) {
-	v, ok := m.ReadUint64Le(offset)
-	if !ok {
-		return 0, false
-	}
-	return math.Float64frombits(v), true
-}
-
-func (m mockMemory) Read(offset, byteCount uint32) ([]byte, bool) {
-	if !m.hasSize(offset, byteCount) {
-		return nil, false
-	}
-	return m[offset : offset+byteCount : offset+byteCount], true
-}
-
-func (m mockMemory) WriteByte(offset uint32, v byte) bool {
-	if offset >= m.Size() {
-		return false
-	}
-	m[offset] = v
-	return true
-}
-
-func (m mockMemory) WriteUint16Le(offset uint32, v uint16) bool {
-	if !m.hasSize(offset, 2) {
-		return false
-	}
-	binary.LittleEndian.PutUint16(m[offset:], v)
-	return true
-}
-
-func (m mockMemory) WriteUint32Le(offset, v uint32) bool {
-	if !m.hasSize(offset, 4) {
-		return false
-	}
-	binary.LittleEndian.PutUint32(m[offset:], v)
-	return true
-}
-
-func (m mockMemory) WriteFloat32Le(offset uint32, v float32) bool {
-	return m.WriteUint32Le(offset, math.Float32bits(v))
-}
-
-func (m mockMemory) WriteUint64Le(offset uint32, v uint64) bool {
-	if !m.hasSize(offset, 8) {
-		return false
-	}
-	binary.LittleEndian.PutUint64(m[offset:], v)
-	return true
-}
-
-func (m mockMemory) WriteFloat64Le(offset uint32, v float64) bool {
-	return m.WriteUint64Le(offset, math.Float64bits(v))
-}
-
-func (m mockMemory) Write(offset uint32, val []byte) bool {
-	if !m.hasSize(offset, uint32(len(val))) {
-		return false
-	}
-	copy(m[offset:], val)
-	return true
-}
-
-func (m mockMemory) WriteString(offset uint32, val string) bool {
-	if !m.hasSize(offset, uint32(len(val))) {
-		return false
-	}
-	copy(m[offset:], val)
-	return true
-}
-
-func (m *mockMemory) Grow(delta uint32) (result uint32, ok bool) {
-	prev := (len(*m) + 65535) / 65536
-	*m = append(*m, make([]byte, 65536*delta)...)
-	return uint32(prev), true
-}
-
-func (m mockMemory) PageSize() (result uint32) {
-	return uint32(len(m) / 65536)
-}
-
-func (m mockMemory) hasSize(offset uint32, byteCount uint32) bool {
-	return uint64(offset)+uint64(byteCount) <= uint64(len(m))
-}

module.go

@@ -3,15 +3,13 @@ package sqlite3
 
 import (
 	"context"
-	"crypto/rand"
 	"io"
 	"math"
 	"os"
-	"runtime"
-	"strconv"
 	"sync"
-	"sync/atomic"
 
+	"github.com/ncruces/go-sqlite3/internal/util"
+	"github.com/ncruces/go-sqlite3/vfs"
 	"github.com/tetratelabs/wazero"
 	"github.com/tetratelabs/wazero/api"
 )
@@ -25,14 +23,14 @@ import (
 var (
 	Binary []byte // WASM binary to load.
 	Path   string // Path to load the binary from.
+	Debug  bool   // Whether to enable SQLite debug stack traces.
 )
 
 var sqlite3 struct {
-	once      sync.Once
-	runtime   wazero.Runtime
-	compiled  wazero.CompiledModule
-	instances atomic.Uint64
-	err       error
+	runtime  wazero.Runtime
+	compiled wazero.CompiledModule
+	err      error
+	once     sync.Once
 }
 
 func instantiateModule() (*module, error) {
@@ -43,12 +41,7 @@ func instantiateModule() (*module, error) {
 		return nil, sqlite3.err
 	}
 
-	name := "sqlite3-" + strconv.FormatUint(sqlite3.instances.Add(1), 10)
-
-	cfg := wazero.NewModuleConfig().WithName(name).
-		WithSysWalltime().WithSysNanotime().WithSysNanosleep().
-		WithOsyield(runtime.Gosched).
-		WithRandSource(rand.Reader)
+	cfg := wazero.NewModuleConfig()
 
 	mod, err := sqlite3.runtime.InstantiateModule(ctx, sqlite3.compiled, cfg)
 	if err != nil {
@@ -59,8 +52,13 @@ func instantiateModule() (*module, error) {
 
 func compileModule() {
 	ctx := context.Background()
-	sqlite3.runtime = wazero.NewRuntime(ctx)
-	vfsInstantiate(ctx, sqlite3.runtime)
+	sqlite3.runtime = wazero.NewRuntimeWithConfig(ctx, wazero.NewRuntimeConfig().WithDebugInfoEnabled(Debug))
+
+	env := vfs.ExportHostFunctions(sqlite3.runtime.NewHostModuleBuilder("env"))
+	_, sqlite3.err = env.Instantiate(ctx)
+	if sqlite3.err != nil {
+		return
+	}
 
 	bin := Binary
 	if bin == nil && Path != "" {
@@ -70,7 +68,7 @@ func compileModule() {
 		}
 	}
 	if bin == nil {
-		sqlite3.err = binaryErr
+		sqlite3.err = util.BinaryErr
 		return
 	}
 
@@ -79,38 +77,39 @@ func compileModule() {
 
 type module struct {
 	ctx context.Context
-	mem memory
-	api sqliteAPI
+	mod api.Module
 	vfs io.Closer
+	api sqliteAPI
+	arg [8]uint64
 }
 
 func newModule(mod api.Module) (m *module, err error) {
-	m = &module{}
-	m.mem = memory{mod}
-	m.ctx, m.vfs = vfsContext(context.Background())
+	m = new(module)
+	m.mod = mod
+	m.ctx, m.vfs = vfs.NewContext(context.Background())
 
 	getFun := func(name string) api.Function {
 		f := mod.ExportedFunction(name)
 		if f == nil {
-			err = noFuncErr + errorString(name)
+			err = util.NoFuncErr + util.ErrorString(name)
 			return nil
 		}
 		return f
 	}
 
 	getVal := func(name string) uint32 {
-		global := mod.ExportedGlobal(name)
-		if global == nil {
-			err = noGlobalErr + errorString(name)
+		g := mod.ExportedGlobal(name)
+		if g == nil {
+			err = util.NoGlobalErr + util.ErrorString(name)
 			return 0
 		}
-		return m.mem.readUint32(uint32(global.Get()))
+		return util.ReadUint32(mod, uint32(g.Get()))
 	}
 
 	m.api = sqliteAPI{
 		free:            getFun("free"),
 		malloc:          getFun("malloc"),
-		destructor:      uint64(getVal("malloc_destructor")),
+		destructor:      getVal("malloc_destructor"),
 		errcode:         getFun("sqlite3_errcode"),
 		errstr:          getFun("sqlite3_errstr"),
 		errmsg:          getFun("sqlite3_errmsg"),
@@ -141,9 +140,6 @@ func newModule(mod api.Module) (m *module, err error) {
 		columnText:      getFun("sqlite3_column_text"),
 		columnBlob:      getFun("sqlite3_column_blob"),
 		columnBytes:     getFun("sqlite3_column_bytes"),
-		autocommit:      getFun("sqlite3_get_autocommit"),
-		lastRowid:       getFun("sqlite3_last_insert_rowid"),
-		changes:         getFun("sqlite3_changes64"),
 		blobOpen:        getFun("sqlite3_blob_open"),
 		blobClose:       getFun("sqlite3_blob_close"),
 		blobReopen:      getFun("sqlite3_blob_reopen"),
@@ -155,7 +151,9 @@ func newModule(mod api.Module) (m *module, err error) {
 		backupFinish:    getFun("sqlite3_backup_finish"),
 		backupRemaining: getFun("sqlite3_backup_remaining"),
 		backupPageCount: getFun("sqlite3_backup_pagecount"),
-		interrupt:       getVal("sqlite3_interrupt_offset"),
+		changes:         getFun("sqlite3_changes64"),
+		lastRowid:       getFun("sqlite3_last_insert_rowid"),
+		autocommit:      getFun("sqlite3_get_autocommit"),
 	}
 	if err != nil {
 		return nil, err
@@ -164,7 +162,7 @@ func newModule(mod api.Module) (m *module, err error) {
 }
 
 func (m *module) close() error {
-	err := m.mem.mod.Close(m.ctx)
+	err := m.mod.Close(m.ctx)
 	m.vfs.Close()
 	return err
 }
@@ -177,25 +175,20 @@ func (m *module) error(rc uint64, handle uint32, sql ...string) error {
 	err := Error{code: rc}
 
 	if err.Code() == NOMEM || err.ExtendedCode() == IOERR_NOMEM {
-		panic(oomErr)
+		panic(util.OOMErr)
 	}
 
-	var r []uint64
-
-	r = m.call(m.api.errstr, rc)
-	if r != nil {
-		err.str = m.mem.readString(uint32(r[0]), _MAX_STRING)
+	if r := m.call(m.api.errstr, rc); r != 0 {
+		err.str = util.ReadString(m.mod, uint32(r), _MAX_STRING)
 	}
 
-	r = m.call(m.api.errmsg, uint64(handle))
-	if r != nil {
-		err.msg = m.mem.readString(uint32(r[0]), _MAX_STRING)
+	if r := m.call(m.api.errmsg, uint64(handle)); r != 0 {
+		err.msg = util.ReadString(m.mod, uint32(r), _MAX_STRING)
 	}
 
 	if sql != nil {
-		r = m.call(m.api.erroff, uint64(handle))
-		if r != nil && r[0] != math.MaxUint32 {
-			err.sql = sql[0][r[0]:]
+		if r := m.call(m.api.erroff, uint64(handle)); r != math.MaxUint32 {
+			err.sql = sql[0][r:]
 		}
 	}
 
@@ -206,14 +199,15 @@ func (m *module) error(rc uint64, handle uint32, sql ...string) error {
 	return &err
 }
 
-func (m *module) call(fn api.Function, params ...uint64) []uint64 {
-	r, err := fn.Call(m.ctx, params...)
+func (m *module) call(fn api.Function, params ...uint64) uint64 {
+	copy(m.arg[:], params)
+	err := fn.CallWithStack(m.ctx, m.arg[:])
 	if err != nil {
 		// The module closed or panicked; release resources.
 		m.vfs.Close()
 		panic(err)
 	}
-	return r
+	return m.arg[0]
 }
 
 func (m *module) free(ptr uint32) {
@@ -225,12 +219,11 @@ func (m *module) free(ptr uint32) {
 
 func (m *module) new(size uint64) uint32 {
 	if size > _MAX_ALLOCATION_SIZE {
-		panic(oomErr)
+		panic(util.OOMErr)
 	}
-	r := m.call(m.api.malloc, size)
-	ptr := uint32(r[0])
+	ptr := uint32(m.call(m.api.malloc, size))
 	if ptr == 0 && size != 0 {
-		panic(oomErr)
+		panic(util.OOMErr)
 	}
 	return ptr
 }
@@ -240,13 +233,13 @@ func (m *module) newBytes(b []byte) uint32 {
 		return 0
 	}
 	ptr := m.new(uint64(len(b)))
-	m.mem.writeBytes(ptr, b)
+	util.WriteBytes(m.mod, ptr, b)
 	return ptr
 }
 
 func (m *module) newString(s string) uint32 {
 	ptr := m.new(uint64(len(s) + 1))
-	m.mem.writeString(ptr, s)
+	util.WriteString(m.mod, ptr, s)
 	return ptr
 }
 
@@ -260,10 +253,10 @@ func (m *module) newArena(size uint64) arena {
 
 type arena struct {
 	m    *module
+	ptrs []uint32
 	base uint32
 	next uint32
 	size uint32
-	ptrs []uint32
 }
 
 func (a *arena) free() {
@@ -294,16 +287,24 @@ func (a *arena) new(size uint64) uint32 {
 	return ptr
 }
 
+func (a *arena) bytes(b []byte) uint32 {
+	if b == nil {
+		return 0
+	}
+	ptr := a.new(uint64(len(b)))
+	util.WriteBytes(a.m.mod, ptr, b)
+	return ptr
+}
+
 func (a *arena) string(s string) uint32 {
 	ptr := a.new(uint64(len(s) + 1))
-	a.m.mem.writeString(ptr, s)
+	util.WriteString(a.m.mod, ptr, s)
 	return ptr
 }
 
 type sqliteAPI struct {
 	free            api.Function
 	malloc          api.Function
-	destructor      uint64
 	errcode         api.Function
 	errstr          api.Function
 	errmsg          api.Function
@@ -334,9 +335,6 @@ type sqliteAPI struct {
 	columnText      api.Function
 	columnBlob      api.Function
 	columnBytes     api.Function
-	autocommit      api.Function
-	lastRowid       api.Function
-	changes         api.Function
 	blobOpen        api.Function
 	blobClose       api.Function
 	blobReopen      api.Function
@@ -348,5 +346,8 @@ type sqliteAPI struct {
 	backupFinish    api.Function
 	backupRemaining api.Function
 	backupPageCount api.Function
-	interrupt       uint32
+	changes         api.Function
+	lastRowid       api.Function
+	autocommit      api.Function
+	destructor      uint32
 }

module_test.go

@@ -4,8 +4,14 @@ import (
 	"bytes"
 	"math"
 	"testing"
+
+	"github.com/ncruces/go-sqlite3/internal/util"
 )
 
+func init() {
+	Path = "./embed/sqlite3.wasm"
+}
+
 func TestConn_error_OOM(t *testing.T) {
 	t.Parallel()
 
@@ -20,14 +26,14 @@ func TestConn_error_OOM(t *testing.T) {
 	t.Error("want panic")
 }
 
-func TestConn_call_nil(t *testing.T) {
+func TestConn_call_closed(t *testing.T) {
 	t.Parallel()
 
 	m, err := instantiateModule()
 	if err != nil {
 		t.Fatal(err)
 	}
-	defer m.close()
+	m.close()
 
 	defer func() { _ = recover() }()
 	m.call(m.api.free)
@@ -43,14 +49,18 @@ func TestConn_new(t *testing.T) {
 	}
 	defer m.close()
 
-	testOOM := func(size uint64) {
+	t.Run("MaxUint32", func(t *testing.T) {
 		defer func() { _ = recover() }()
-		m.new(size)
+		m.new(math.MaxUint32)
 		t.Error("want panic")
-	}
+	})
 
-	testOOM(math.MaxUint32)
-	testOOM(_MAX_ALLOCATION_SIZE)
+	t.Run("_MAX_ALLOCATION_SIZE", func(t *testing.T) {
+		defer func() { _ = recover() }()
+		m.new(_MAX_ALLOCATION_SIZE)
+		m.new(_MAX_ALLOCATION_SIZE)
+		t.Error("want panic")
+	})
 }
 
 func TestConn_newArena(t *testing.T) {
@@ -66,12 +76,11 @@ func TestConn_newArena(t *testing.T) {
 	defer arena.free()
 
 	const title = "Lorem ipsum"
-
 	ptr := arena.string(title)
 	if ptr == 0 {
 		t.Fatalf("got nullptr")
 	}
-	if got := m.mem.readString(ptr, math.MaxUint32); got != title {
+	if got := util.ReadString(m.mod, ptr, math.MaxUint32); got != title {
 		t.Errorf("got %q, want %q", got, title)
 	}
 
@@ -80,9 +89,22 @@ func TestConn_newArena(t *testing.T) {
 	if ptr == 0 {
 		t.Fatalf("got nullptr")
 	}
-	if got := m.mem.readString(ptr, math.MaxUint32); got != body {
+	if got := util.ReadString(m.mod, ptr, math.MaxUint32); got != body {
 		t.Errorf("got %q, want %q", got, body)
 	}
+
+	ptr = arena.bytes(nil)
+	if ptr != 0 {
+		t.Errorf("want nullptr")
+	}
+	ptr = arena.bytes([]byte(title))
+	if ptr == 0 {
+		t.Fatalf("got nullptr")
+	}
+	if got := util.View(m.mod, ptr, uint64(len(title))); string(got) != title {
+		t.Errorf("got %q, want %q", got, title)
+	}
+
 	arena.free()
 }
 
@@ -107,7 +129,7 @@ func TestConn_newBytes(t *testing.T) {
 	}
 
 	want := buf
-	if got := m.mem.view(ptr, uint64(len(want))); !bytes.Equal(got, want) {
+	if got := util.View(m.mod, ptr, uint64(len(want))); !bytes.Equal(got, want) {
 		t.Errorf("got %q, want %q", got, want)
 	}
 }
@@ -133,7 +155,7 @@ func TestConn_newString(t *testing.T) {
 	}
 
 	want := str + "\000"
-	if got := m.mem.view(ptr, uint64(len(want))); string(got) != want {
+	if got := util.View(m.mod, ptr, uint64(len(want))); string(got) != want {
 		t.Errorf("got %q, want %q", got, want)
 	}
 }
@@ -159,22 +181,22 @@ func TestConn_getString(t *testing.T) {
 	}
 
 	want := "sqlite3"
-	if got := m.mem.readString(ptr, math.MaxUint32); got != want {
+	if got := util.ReadString(m.mod, ptr, math.MaxUint32); got != want {
 		t.Errorf("got %q, want %q", got, want)
 	}
-	if got := m.mem.readString(ptr, 0); got != "" {
+	if got := util.ReadString(m.mod, ptr, 0); got != "" {
 		t.Errorf("got %q, want empty", got)
 	}
 
 	func() {
 		defer func() { _ = recover() }()
-		m.mem.readString(ptr, uint32(len(want)/2))
+		util.ReadString(m.mod, ptr, uint32(len(want)/2))
 		t.Error("want panic")
 	}()
 
 	func() {
 		defer func() { _ = recover() }()
-		m.mem.readString(0, math.MaxUint32)
+		util.ReadString(m.mod, 0, math.MaxUint32)
 		t.Error("want panic")
 	}()
 }

sqlite3/amalg.c

@@ -1,9 +0,0 @@
-#include <stddef.h>
-
-#include "main.c"
-#include "os.c"
-#include "qsort.c"
-#include "sqlite3.c"
-
-sqlite3_destructor_type malloc_destructor = &free;
-size_t sqlite3_interrupt_offset = offsetof(sqlite3, u1.isInterrupted);

sqlite3/deserialize.patch

@@ -0,0 +1,20 @@
+--- sqlite3.c.orig
++++ sqlite3.c
+@@ -60425,7 +60425,7 @@
+   int rc = SQLITE_OK;      /* Return code */
+   int tempFile = 0;        /* True for temp files (incl. in-memory files) */
+   int memDb = 0;           /* True if this is an in-memory file */
+-#ifndef SQLITE_OMIT_DESERIALIZE
++#if 1
+   int memJM = 0;           /* Memory journal mode */
+ #else
+ # define memJM 0
+@@ -60628,7 +60628,7 @@
+     int fout = 0;                    /* VFS flags returned by xOpen() */
+     rc = sqlite3OsOpen(pVfs, pPager->zFilename, pPager->fd, vfsFlags, &fout);
+     assert( !memDb );
+-#ifndef SQLITE_OMIT_DESERIALIZE
++#if 1
+     pPager->memVfs = memJM = (fout&SQLITE_OPEN_MEMORY)!=0;
+ #endif
+     readOnly = (fout&SQLITE_OPEN_READONLY)!=0;

sqlite3/download.sh

@@ -1,13 +1,34 @@
 #!/usr/bin/env bash
-set -eo pipefail
+set -euo pipefail
 
 cd -P -- "$(dirname -- "$0")"
 
-if [ ! -f "sqlite3.c" ]; then
-	url="https://sqlite.org/2023/sqlite-amalgamation-3410000.zip"
-	curl "$url" > sqlite.zip
-	unzip -d . sqlite.zip
-	mv sqlite-amalgamation-*/sqlite3* .
-	rm -rf sqlite-amalgamation-*
-	rm sqlite.zip
-fi
+curl -#OL "https://sqlite.org/2023/sqlite-amalgamation-3420000.zip"
+unzip -d . sqlite-amalgamation-*.zip
+mv sqlite-amalgamation-*/sqlite3* .
+rm -rf sqlite-amalgamation-*
+
+patch < vfs_find.patch
+patch < deserialize.patch
+
+cd ext/
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.42.0/ext/misc/decimal.c"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.42.0/ext/misc/uint.c"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.42.0/ext/misc/uuid.c"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.42.0/ext/misc/base64.c"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.42.0/ext/misc/regexp.c"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.42.0/ext/misc/series.c"
+cd ~-
+
+cd ../vfs/tests/mptest/testdata/
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.42.0/mptest/mptest.c"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.42.0/mptest/config01.test"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.42.0/mptest/config02.test"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.42.0/mptest/crash01.test"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.42.0/mptest/crash02.subtest"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.42.0/mptest/multiwrite01.test"
+cd ~-
+
+cd ../vfs/tests/speedtest1/testdata/
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.42.0/test/speedtest1.c"
+cd ~-

sqlite3/ext/.gitignore

@@ -0,0 +1 @@
+*.c

sqlite3/format.sh

@@ -1,8 +1,7 @@
 #!/usr/bin/env bash
+set -euo pipefail
+
 cd -P -- "$(dirname -- "$0")"
 
-clang-format -i \
-	main.c \
-	os.c \
-	qsort.c \
-	amalg.c
+shopt -s extglob
+clang-format -i !(sqlite3*).@(c|h)

sqlite3/main.c

@@ -1,14 +1,28 @@
 #include <stdbool.h>
+#include <stddef.h>
 
-#include "sqlite3.h"
+// Configuration
+#include "sqlite_cfg.h"
+// Amalgamation
+#include "sqlite3.c"
+// VFS
+#include "vfs.c"
+// Extensions
+#include "ext/base64.c"
+#include "ext/decimal.c"
+#include "ext/regexp.c"
+#include "ext/series.c"
+#include "ext/uint.c"
+#include "ext/uuid.c"
+#include "time.c"
 
-int main() {
-  int rc = sqlite3_initialize();
-  if (rc != SQLITE_OK) return 1;
-}
-
-sqlite3_vfs *os_vfs();
-
-int sqlite3_os_init() {
-  return sqlite3_vfs_register(os_vfs(), /*default=*/true);
+__attribute__((constructor)) void init() {
+  sqlite3_initialize();
+  sqlite3_auto_extension((void (*)(void))sqlite3_base_init);
+  sqlite3_auto_extension((void (*)(void))sqlite3_decimal_init);
+  sqlite3_auto_extension((void (*)(void))sqlite3_regexp_init);
+  sqlite3_auto_extension((void (*)(void))sqlite3_series_init);
+  sqlite3_auto_extension((void (*)(void))sqlite3_uint_init);
+  sqlite3_auto_extension((void (*)(void))sqlite3_uuid_init);
+  sqlite3_auto_extension((void (*)(void))sqlite3_time_init);
 }

sqlite3/os.c

@@ -1,92 +0,0 @@
-#include <time.h>
-
-#include "sqlite3.h"
-
-int os_localtime(sqlite3_int64, struct tm *);
-
-int os_randomness(sqlite3_vfs *, int nByte, char *zOut);
-int os_sleep(sqlite3_vfs *, int microseconds);
-int os_current_time(sqlite3_vfs *, double *);
-int os_current_time_64(sqlite3_vfs *, sqlite3_int64 *);
-
-int os_open(sqlite3_vfs *, sqlite3_filename zName, sqlite3_file *, int flags,
-            int *pOutFlags);
-int os_delete(sqlite3_vfs *, const char *zName, int syncDir);
-int os_access(sqlite3_vfs *, const char *zName, int flags, int *pResOut);
-int os_full_pathname(sqlite3_vfs *, const char *zName, int nOut, char *zOut);
-
-struct os_file {
-  sqlite3_file base;
-  int id;
-  int lock;
-};
-
-int os_close(sqlite3_file *);
-int os_read(sqlite3_file *, void *, int iAmt, sqlite3_int64 iOfst);
-int os_write(sqlite3_file *, const void *, int iAmt, sqlite3_int64 iOfst);
-int os_truncate(sqlite3_file *, sqlite3_int64 size);
-int os_sync(sqlite3_file *, int flags);
-int os_file_size(sqlite3_file *, sqlite3_int64 *pSize);
-int os_file_control(sqlite3_file *pFile, int op, void *pArg);
-
-int os_lock(sqlite3_file *pFile, int eLock);
-int os_unlock(sqlite3_file *pFile, int eLock);
-int os_check_reserved_lock(sqlite3_file *pFile, int *pResOut);
-
-static int no_lock(sqlite3_file *pFile, int eLock) { return SQLITE_OK; }
-static int no_unlock(sqlite3_file *pFile, int eLock) { return SQLITE_OK; }
-static int no_check_reserved_lock(sqlite3_file *pFile, int *pResOut) {
-  *pResOut = 0;
-  return SQLITE_OK;
-}
-
-static int no_file_control(sqlite3_file *pFile, int op, void *pArg) {
-  return SQLITE_NOTFOUND;
-}
-static int no_sector_size(sqlite3_file *pFile) { return 0; }
-static int no_device_characteristics(sqlite3_file *pFile) { return 0; }
-
-int localtime_s(struct tm *const pTm, time_t const *const pTime) {
-  return os_localtime((sqlite3_int64)*pTime, pTm);
-}
-
-static int os_open_w(sqlite3_vfs *vfs, sqlite3_filename zName,
-                     sqlite3_file *file, int flags, int *pOutFlags) {
-  static const sqlite3_io_methods os_io = {
-      .iVersion = 1,
-      .xClose = os_close,
-      .xRead = os_read,
-      .xWrite = os_write,
-      .xTruncate = os_truncate,
-      .xSync = os_sync,
-      .xFileSize = os_file_size,
-      .xLock = os_lock,
-      .xUnlock = os_unlock,
-      .xCheckReservedLock = os_check_reserved_lock,
-      .xFileControl = no_file_control,
-      .xDeviceCharacteristics = no_device_characteristics,
-  };
-  int rc = os_open(vfs, zName, file, flags, pOutFlags);
-  file->pMethods = (char)rc == SQLITE_OK ? &os_io : NULL;
-  return rc;
-}
-
-sqlite3_vfs *os_vfs() {
-  static sqlite3_vfs os_vfs = {
-      .iVersion = 2,
-      .szOsFile = sizeof(struct os_file),
-      .mxPathname = 512,
-      .zName = "os",
-
-      .xOpen = os_open_w,
-      .xDelete = os_delete,
-      .xAccess = os_access,
-      .xFullPathname = os_full_pathname,
-
-      .xRandomness = os_randomness,
-      .xSleep = os_sleep,
-      .xCurrentTime = os_current_time,
-      .xCurrentTimeInt64 = os_current_time_64,
-  };
-  return &os_vfs;
-}

sqlite3/qsort.c

@@ -1,14 +0,0 @@
-#include <stddef.h>
-
-void qsort_r(void *, size_t, size_t,
-             int (*)(const void *, const void *, void *), void *);
-
-typedef int (*cmpfun)(const void *, const void *);
-
-static int wrapper_cmp(const void *v1, const void *v2, void *cmp) {
-  return ((cmpfun)cmp)(v1, v2);
-}
-
-void qsort(void *base, size_t nel, size_t width, cmpfun cmp) {
-  qsort_r(base, nel, width, wrapper_cmp, cmp);
-}

sqlite3/sqlite_cfg.h

@@ -28,8 +28,14 @@
 #define SQLITE_OMIT_AUTOINIT
 #define SQLITE_USE_ALLOCA
 
+// Other Options
+#define SQLITE_ALLOW_URI_AUTHORITY
+#define SQLITE_ENABLE_BATCH_ATOMIC_WRITE
+#define SQLITE_ENABLE_ATOMIC_WRITE
+#define SQLITE_OMIT_DESERIALIZE
+
 // Because WASM does not support shared memory,
-// SQLite disables it for WASM builds.
+// SQLite disables WAL for WASM builds.
 // We set the default locking mode to EXCLUSIVE instead.
 // https://www.sqlite.org/wal.html#noshm
 #undef SQLITE_OMIT_WAL
@@ -37,7 +43,7 @@
 #define SQLITE_DEFAULT_LOCKING_MODE 1
 #endif
 
-// Recommended Extensions
+// Amalgamated Extensions
 
 #define SQLITE_ENABLE_MATH_FUNCTIONS 1
 #define SQLITE_ENABLE_JSON1 1
@@ -48,15 +54,9 @@
 #define SQLITE_ENABLE_RTREE 1
 #define SQLITE_ENABLE_GEOPOLY 1
 
-// Snapshot
-// #define SQLITE_ENABLE_SNAPSHOT 1
-
 // Session Extension
-// #define SQLITE_ENABLE_SESSION 1
-// #define SQLITE_ENABLE_PREUPDATE_HOOK 1
+// #define SQLITE_ENABLE_SESSION
+// #define SQLITE_ENABLE_PREUPDATE_HOOK
 
-// Resumable Bulk Update Extension
-// #define SQLITE_ENABLE_RBU 1
-
-// Implemented in Go.
+// Implemented in vfs.c.
 int localtime_s(struct tm *const pTm, time_t const *const pTime);

sqlite3/time.c

@@ -0,0 +1,32 @@
+#include <string.h>
+
+#include "sqlite3.h"
+
+static int time_collation(void *pArg, int nKey1, const void *pKey1, int nKey2,
+                          const void *pKey2) {
+  // Remove a Z suffix if one key is no longer than the other.
+  // A Z suffix collates before any character but after the empty string.
+  // This avoids making different keys equal.
+  const int nK1 = nKey1;
+  const int nK2 = nKey2;
+  const char *pK1 = (const char *)pKey1;
+  const char *pK2 = (const char *)pKey2;
+  if (nK1 && nK1 <= nK2 && pK1[nK1 - 1] == 'Z') {
+    nKey1--;
+  }
+  if (nK2 && nK2 <= nK1 && pK2[nK2 - 1] == 'Z') {
+    nKey2--;
+  }
+
+  int n = nKey1 < nKey2 ? nKey1 : nKey2;
+  int rc = memcmp(pKey1, pKey2, n);
+  if (rc == 0) {
+    rc = nKey1 - nKey2;
+  }
+  return rc;
+}
+
+int sqlite3_time_init(sqlite3 *db, char **pzErrMsg,
+                      const sqlite3_api_routines *pApi) {
+  return sqlite3_create_collation(db, "time", SQLITE_UTF8, 0, time_collation);
+}

sqlite3/vfs.c

@@ -0,0 +1,137 @@
+#include <time.h>
+
+#include "sqlite3.h"
+
+int go_localtime(struct tm *, sqlite3_int64);
+int go_vfs_find(const char *zVfsName);
+
+int go_randomness(sqlite3_vfs *, int nByte, char *zOut);
+int go_sleep(sqlite3_vfs *, int microseconds);
+int go_current_time(sqlite3_vfs *, double *);
+int go_current_time_64(sqlite3_vfs *, sqlite3_int64 *);
+
+int go_open(sqlite3_vfs *, sqlite3_filename zName, sqlite3_file *, int flags,
+            int *pOutFlags);
+int go_delete(sqlite3_vfs *, const char *zName, int syncDir);
+int go_access(sqlite3_vfs *, const char *zName, int flags, int *pResOut);
+int go_full_pathname(sqlite3_vfs *, const char *zName, int nOut, char *zOut);
+
+int go_close(sqlite3_file *);
+int go_read(sqlite3_file *, void *, int iAmt, sqlite3_int64 iOfst);
+int go_write(sqlite3_file *, const void *, int iAmt, sqlite3_int64 iOfst);
+int go_truncate(sqlite3_file *, sqlite3_int64 size);
+int go_sync(sqlite3_file *, int flags);
+int go_file_size(sqlite3_file *, sqlite3_int64 *pSize);
+int go_file_control(sqlite3_file *, int op, void *pArg);
+int go_sector_size(sqlite3_file *file);
+int go_device_characteristics(sqlite3_file *file);
+
+int go_lock(sqlite3_file *, int eLock);
+int go_unlock(sqlite3_file *, int eLock);
+int go_check_reserved_lock(sqlite3_file *, int *pResOut);
+
+static int go_open_wrapper(sqlite3_vfs *vfs, sqlite3_filename zName,
+                           sqlite3_file *file, int flags, int *pOutFlags) {
+  static const sqlite3_io_methods os_io = {
+      .iVersion = 1,
+      .xClose = go_close,
+      .xRead = go_read,
+      .xWrite = go_write,
+      .xTruncate = go_truncate,
+      .xSync = go_sync,
+      .xFileSize = go_file_size,
+      .xLock = go_lock,
+      .xUnlock = go_unlock,
+      .xCheckReservedLock = go_check_reserved_lock,
+      .xFileControl = go_file_control,
+      .xSectorSize = go_sector_size,
+      .xDeviceCharacteristics = go_device_characteristics,
+  };
+  memset(file, 0, vfs->szOsFile);
+  int rc = go_open(vfs, zName, file, flags, pOutFlags);
+  if (rc) {
+    return rc;
+  }
+  file->pMethods = &os_io;
+  return SQLITE_OK;
+}
+
+struct go_file {
+  sqlite3_file base;
+  int handle;
+};
+
+int sqlite3_os_init() {
+  static sqlite3_vfs os_vfs = {
+      .iVersion = 2,
+      .szOsFile = sizeof(struct go_file),
+      .mxPathname = 512,
+      .zName = "os",
+
+      .xOpen = go_open_wrapper,
+      .xDelete = go_delete,
+      .xAccess = go_access,
+      .xFullPathname = go_full_pathname,
+
+      .xRandomness = go_randomness,
+      .xSleep = go_sleep,
+      .xCurrentTime = go_current_time,
+      .xCurrentTimeInt64 = go_current_time_64,
+  };
+  return sqlite3_vfs_register(&os_vfs, /*default=*/true);
+}
+
+sqlite3_destructor_type malloc_destructor = &free;
+
+int localtime_s(struct tm *const pTm, time_t const *const pTime) {
+  return go_localtime(pTm, (sqlite3_int64)*pTime);
+}
+
+sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName) {
+  if (zVfsName) {
+    static sqlite3_vfs *go_vfs_list;
+    sqlite3_vfs *found = NULL;
+    for (sqlite3_vfs **next = &go_vfs_list; *next;) {
+      sqlite3_vfs *it = *next;
+      if (go_vfs_find(it->zName)) {
+        if (!strcmp(zVfsName, it->zName)) found = it;
+        next = &it->pNext;
+      } else {
+        *next = it->pNext;
+        free(it);
+      }
+    }
+    if (found) {
+      return found;
+    }
+    if (go_vfs_find(zVfsName)) {
+      sqlite3_vfs *prev = go_vfs_list;
+      go_vfs_list = malloc(sizeof(sqlite3_vfs) + strlen(zVfsName) + 1);
+      char *name = (char *)(go_vfs_list + 1);
+      strcpy(name, zVfsName);
+      *go_vfs_list = (sqlite3_vfs){
+          .iVersion = 2,
+          .szOsFile = sizeof(struct go_file),
+          .mxPathname = 512,
+          .zName = name,
+          .pNext = prev,
+
+          .xOpen = go_open_wrapper,
+          .xDelete = go_delete,
+          .xAccess = go_access,
+          .xFullPathname = go_full_pathname,
+
+          .xRandomness = go_randomness,
+          .xSleep = go_sleep,
+          .xCurrentTime = go_current_time,
+          .xCurrentTimeInt64 = go_current_time_64,
+      };
+      return go_vfs_list;
+    }
+  }
+  return sqlite3_vfs_find_orig(zVfsName);
+}
+
+static_assert(offsetof(struct go_file, handle) == 4, "Unexpected offset");
+static_assert(offsetof(sqlite3_vfs, zName) == 16, "Unexpected offset");
+static_assert(offsetof(sqlite3, u1.isInterrupted) == 280, "Unexpected offset");

sqlite3/vfs_find.patch

@@ -0,0 +1,11 @@
+--- sqlite3.c.orig
++++ sqlite3.c
+@@ -25394,7 +25394,7 @@
+ ** Locate a VFS by name.  If no name is given, simply return the
+ ** first VFS on the list.
+ */
+-SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfs){
++SQLITE_API sqlite3_vfs *sqlite3_vfs_find_orig(const char *zVfs){
+   sqlite3_vfs *pVfs = 0;
+ #if SQLITE_THREADSAFE
+   sqlite3_mutex *mutex;

stmt.go

@@ -3,6 +3,8 @@ package sqlite3
 import (
 	"math"
 	"time"
+
+	"github.com/ncruces/go-sqlite3/internal/util"
 )
 
 // Stmt is a prepared statement object.
@@ -10,8 +12,8 @@ import (
 // https://www.sqlite.org/c3ref/stmt.html
 type Stmt struct {
 	c      *Conn
-	handle uint32
 	err    error
+	handle uint32
 }
 
 // Close destroys the prepared statement object.
@@ -27,7 +29,7 @@ func (s *Stmt) Close() error {
 	r := s.c.call(s.c.api.finalize, uint64(s.handle))
 
 	s.handle = 0
-	return s.c.error(r[0])
+	return s.c.error(r)
 }
 
 // Reset resets the prepared statement object.
@@ -36,7 +38,7 @@ func (s *Stmt) Close() error {
 func (s *Stmt) Reset() error {
 	r := s.c.call(s.c.api.reset, uint64(s.handle))
 	s.err = nil
-	return s.c.error(r[0])
+	return s.c.error(r)
 }
 
 // ClearBindings resets all bindings on the prepared statement.
@@ -44,7 +46,7 @@ func (s *Stmt) Reset() error {
 // https://www.sqlite.org/c3ref/clear_bindings.html
 func (s *Stmt) ClearBindings() error {
 	r := s.c.call(s.c.api.clearBindings, uint64(s.handle))
-	return s.c.error(r[0])
+	return s.c.error(r)
 }
 
 // Step evaluates the SQL statement.
@@ -59,13 +61,13 @@ func (s *Stmt) ClearBindings() error {
 func (s *Stmt) Step() bool {
 	s.c.checkInterrupt()
 	r := s.c.call(s.c.api.step, uint64(s.handle))
-	if r[0] == _ROW {
+	if r == _ROW {
 		return true
 	}
-	if r[0] == _DONE {
+	if r == _DONE {
 		s.err = nil
 	} else {
-		s.err = s.c.error(r[0])
+		s.err = s.c.error(r)
 	}
 	return false
 }
@@ -92,7 +94,7 @@ func (s *Stmt) Exec() error {
 func (s *Stmt) BindCount() int {
 	r := s.c.call(s.c.api.bindCount,
 		uint64(s.handle))
-	return int(r[0])
+	return int(r)
 }
 
 // BindIndex returns the index of a parameter in the prepared statement
@@ -104,7 +106,7 @@ func (s *Stmt) BindIndex(name string) int {
 	namePtr := s.c.arena.string(name)
 	r := s.c.call(s.c.api.bindIndex,
 		uint64(s.handle), uint64(namePtr))
-	return int(r[0])
+	return int(r)
 }
 
 // BindName returns the name of a parameter in the prepared statement.
@@ -115,11 +117,11 @@ func (s *Stmt) BindName(param int) string {
 	r := s.c.call(s.c.api.bindName,
 		uint64(s.handle), uint64(param))
 
-	ptr := uint32(r[0])
+	ptr := uint32(r)
 	if ptr == 0 {
 		return ""
 	}
-	return s.c.mem.readString(ptr, _MAX_STRING)
+	return util.ReadString(s.c.mod, ptr, _MAX_STRING)
 }
 
 // BindBool binds a bool to the prepared statement.
@@ -150,7 +152,7 @@ func (s *Stmt) BindInt(param int, value int) error {
 func (s *Stmt) BindInt64(param int, value int64) error {
 	r := s.c.call(s.c.api.bindInteger,
 		uint64(s.handle), uint64(param), uint64(value))
-	return s.c.error(r[0])
+	return s.c.error(r)
 }
 
 // BindFloat binds a float64 to the prepared statement.
@@ -160,7 +162,7 @@ func (s *Stmt) BindInt64(param int, value int64) error {
 func (s *Stmt) BindFloat(param int, value float64) error {
 	r := s.c.call(s.c.api.bindFloat,
 		uint64(s.handle), uint64(param), math.Float64bits(value))
-	return s.c.error(r[0])
+	return s.c.error(r)
 }
 
 // BindText binds a string to the prepared statement.
@@ -172,8 +174,8 @@ func (s *Stmt) BindText(param int, value string) error {
 	r := s.c.call(s.c.api.bindText,
 		uint64(s.handle), uint64(param),
 		uint64(ptr), uint64(len(value)),
-		s.c.api.destructor, _UTF8)
-	return s.c.error(r[0])
+		uint64(s.c.api.destructor), _UTF8)
+	return s.c.error(r)
 }
 
 // BindBlob binds a []byte to the prepared statement.
@@ -186,8 +188,8 @@ func (s *Stmt) BindBlob(param int, value []byte) error {
 	r := s.c.call(s.c.api.bindBlob,
 		uint64(s.handle), uint64(param),
 		uint64(ptr), uint64(len(value)),
-		s.c.api.destructor)
-	return s.c.error(r[0])
+		uint64(s.c.api.destructor))
+	return s.c.error(r)
 }
 
 // BindZeroBlob binds a zero-filled, length n BLOB to the prepared statement.
@@ -197,7 +199,7 @@ func (s *Stmt) BindBlob(param int, value []byte) error {
 func (s *Stmt) BindZeroBlob(param int, n int64) error {
 	r := s.c.call(s.c.api.bindZeroBlob,
 		uint64(s.handle), uint64(param), uint64(n))
-	return s.c.error(r[0])
+	return s.c.error(r)
 }
 
 // BindNull binds a NULL to the prepared statement.
@@ -207,7 +209,7 @@ func (s *Stmt) BindZeroBlob(param int, n int64) error {
 func (s *Stmt) BindNull(param int) error {
 	r := s.c.call(s.c.api.bindNull,
 		uint64(s.handle), uint64(param))
-	return s.c.error(r[0])
+	return s.c.error(r)
 }
 
 // BindTime binds a [time.Time] to the prepared statement.
@@ -215,6 +217,9 @@ func (s *Stmt) BindNull(param int) error {
 //
 // https://www.sqlite.org/c3ref/bind_blob.html
 func (s *Stmt) BindTime(param int, value time.Time, format TimeFormat) error {
+	if format == TimeFormatDefault {
+		return s.bindRFC3339Nano(param, value)
+	}
 	switch v := format.Encode(value).(type) {
 	case string:
 		s.BindText(param, v)
@@ -223,18 +228,32 @@ func (s *Stmt) BindTime(param int, value time.Time, format TimeFormat) error {
 	case float64:
 		s.BindFloat(param, v)
 	default:
-		panic(assertErr())
+		panic(util.AssertErr())
 	}
 	return nil
 }
 
+func (s *Stmt) bindRFC3339Nano(param int, value time.Time) error {
+	const maxlen = uint64(len(time.RFC3339Nano))
+
+	ptr := s.c.new(maxlen)
+	buf := util.View(s.c.mod, ptr, maxlen)
+	buf = value.AppendFormat(buf[:0], time.RFC3339Nano)
+
+	r := s.c.call(s.c.api.bindText,
+		uint64(s.handle), uint64(param),
+		uint64(ptr), uint64(len(buf)),
+		uint64(s.c.api.destructor), _UTF8)
+	return s.c.error(r)
+}
+
 // ColumnCount returns the number of columns in a result set.
 //
 // https://www.sqlite.org/c3ref/column_count.html
 func (s *Stmt) ColumnCount() int {
 	r := s.c.call(s.c.api.columnCount,
 		uint64(s.handle))
-	return int(r[0])
+	return int(r)
 }
 
 // ColumnName returns the name of the result column.
@@ -245,11 +264,11 @@ func (s *Stmt) ColumnName(col int) string {
 	r := s.c.call(s.c.api.columnName,
 		uint64(s.handle), uint64(col))
 
-	ptr := uint32(r[0])
+	ptr := uint32(r)
 	if ptr == 0 {
-		panic(oomErr)
+		panic(util.OOMErr)
 	}
-	return s.c.mem.readString(ptr, _MAX_STRING)
+	return util.ReadString(s.c.mod, ptr, _MAX_STRING)
 }
 
 // ColumnType returns the initial [Datatype] of the result column.
@@ -259,7 +278,7 @@ func (s *Stmt) ColumnName(col int) string {
 func (s *Stmt) ColumnType(col int) Datatype {
 	r := s.c.call(s.c.api.columnType,
 		uint64(s.handle), uint64(col))
-	return Datatype(r[0])
+	return Datatype(r)
 }
 
 // ColumnBool returns the value of the result column as a bool.
@@ -291,7 +310,7 @@ func (s *Stmt) ColumnInt(col int) int {
 func (s *Stmt) ColumnInt64(col int) int64 {
 	r := s.c.call(s.c.api.columnInteger,
 		uint64(s.handle), uint64(col))
-	return int64(r[0])
+	return int64(r)
 }
 
 // ColumnFloat returns the value of the result column as a float64.
@@ -301,7 +320,7 @@ func (s *Stmt) ColumnInt64(col int) int64 {
 func (s *Stmt) ColumnFloat(col int) float64 {
 	r := s.c.call(s.c.api.columnFloat,
 		uint64(s.handle), uint64(col))
-	return math.Float64frombits(r[0])
+	return math.Float64frombits(r)
 }
 
 // ColumnTime returns the value of the result column as a [time.Time].
@@ -320,7 +339,7 @@ func (s *Stmt) ColumnTime(col int, format TimeFormat) time.Time {
 	case NULL:
 		return time.Time{}
 	default:
-		panic(assertErr())
+		panic(util.AssertErr())
 	}
 	t, err := format.Decode(v)
 	if err != nil {
@@ -334,21 +353,7 @@ func (s *Stmt) ColumnTime(col int, format TimeFormat) time.Time {
 //
 // https://www.sqlite.org/c3ref/column_blob.html
 func (s *Stmt) ColumnText(col int) string {
-	r := s.c.call(s.c.api.columnText,
-		uint64(s.handle), uint64(col))
-
-	ptr := uint32(r[0])
-	if ptr == 0 {
-		r = s.c.call(s.c.api.errcode, uint64(s.c.handle))
-		s.err = s.c.error(r[0])
-		return ""
-	}
-
-	r = s.c.call(s.c.api.columnBytes,
-		uint64(s.handle), uint64(col))
-
-	mem := s.c.mem.view(ptr, r[0])
-	return string(mem)
+	return string(s.ColumnRawText(col))
 }
 
 // ColumnBlob appends to buf and returns
@@ -357,21 +362,53 @@ func (s *Stmt) ColumnText(col int) string {
 //
 // https://www.sqlite.org/c3ref/column_blob.html
 func (s *Stmt) ColumnBlob(col int, buf []byte) []byte {
-	r := s.c.call(s.c.api.columnBlob,
+	return append(buf, s.ColumnRawBlob(col)...)
+}
+
+// ColumnRawText returns the value of the result column as a []byte.
+// The []byte is owned by SQLite and may be invalidated by
+// subsequent calls to [Stmt] methods.
+// The leftmost column of the result set has the index 0.
+//
+// https://www.sqlite.org/c3ref/column_blob.html
+func (s *Stmt) ColumnRawText(col int) []byte {
+	r := s.c.call(s.c.api.columnText,
 		uint64(s.handle), uint64(col))
 
-	ptr := uint32(r[0])
+	ptr := uint32(r)
 	if ptr == 0 {
 		r = s.c.call(s.c.api.errcode, uint64(s.c.handle))
-		s.err = s.c.error(r[0])
-		return buf[0:0]
+		s.err = s.c.error(r)
+		return nil
 	}
 
 	r = s.c.call(s.c.api.columnBytes,
 		uint64(s.handle), uint64(col))
 
-	mem := s.c.mem.view(ptr, r[0])
-	return append(buf[0:0], mem...)
+	return util.View(s.c.mod, ptr, r)
+}
+
+// ColumnRawBlob returns the value of the result column as a []byte.
+// The []byte is owned by SQLite and may be invalidated by
+// subsequent calls to [Stmt] methods.
+// The leftmost column of the result set has the index 0.
+//
+// https://www.sqlite.org/c3ref/column_blob.html
+func (s *Stmt) ColumnRawBlob(col int) []byte {
+	r := s.c.call(s.c.api.columnBlob,
+		uint64(s.handle), uint64(col))
+
+	ptr := uint32(r)
+	if ptr == 0 {
+		r = s.c.call(s.c.api.errcode, uint64(s.c.handle))
+		s.err = s.c.error(r)
+		return nil
+	}
+
+	r = s.c.call(s.c.api.columnBytes,
+		uint64(s.handle), uint64(col))
+
+	return util.View(s.c.mod, ptr, r)
 }
 
 // Return true if stmt is an empty SQL statement.

tests/backup_test.go

@@ -124,4 +124,46 @@ func TestBackup(t *testing.T) {
 			t.Fatal(err)
 		}
 	}()
+
+	func() { // Incremental.
+		db, err := sqlite3.Open(backupName)
+		if err != nil {
+			t.Fatal(err)
+		}
+		defer db.Close()
+
+		b, err := db.BackupInit("main", ":memory:")
+		if err != nil {
+			t.Fatal(err)
+		}
+		defer b.Close()
+
+		done, err := b.Step(1)
+		if done {
+			t.Error("want false")
+		}
+		if err != nil {
+			t.Error(err)
+		}
+
+		n := b.Remaining()
+		if n != 1 {
+			t.Errorf("got %d", n)
+		}
+
+		n = b.PageCount()
+		if n != 2 {
+			t.Errorf("got %d", n)
+		}
+
+		err = b.Close()
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		err = db.Close()
+		if err != nil {
+			t.Fatal(err)
+		}
+	}()
 }

tests/blob_test.go

@@ -5,6 +5,7 @@ import (
 	"crypto/rand"
 	"errors"
 	"fmt"
+	"hash/adler32"
 	"io"
 	"testing"
 
@@ -48,17 +49,17 @@ func TestBlob(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	_, err = io.Copy(blob, bytes.NewReader(data[:size/2]))
+	_, err = blob.Write(data[:size/2])
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	_, err = io.Copy(blob, bytes.NewReader(data[:]))
-	if !errors.Is(err, sqlite3.ERROR) {
-		t.Fatal("want error")
+	n, err := blob.Write(data[:])
+	if n != 0 || !errors.Is(err, sqlite3.ERROR) {
+		t.Fatalf("got (%d, %v), want (0, ERROR)", n, err)
 	}
 
-	_, err = io.Copy(blob, bytes.NewReader(data[size/2:size]))
+	_, err = blob.Write(data[size/2 : size])
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -87,6 +88,126 @@ func TestBlob(t *testing.T) {
 	}
 }
 
+func TestBlob_large(t *testing.T) {
+	t.Parallel()
+
+	db, err := sqlite3.Open(":memory:")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+
+	err = db.Exec(`CREATE TABLE IF NOT EXISTS test (col)`)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = db.Exec(`INSERT INTO test VALUES (zeroblob(1000000))`)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	blob, err := db.OpenBlob("main", "test", "col", db.LastInsertRowID(), true)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer blob.Close()
+
+	size := blob.Size()
+	if size != 1000000 {
+		t.Errorf("got %d, want 1000000", size)
+	}
+
+	hash := adler32.New()
+	_, err = io.CopyN(blob, io.TeeReader(rand.Reader, hash), 1000000)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, err = blob.Seek(0, io.SeekStart)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	want := hash.Sum32()
+	hash.Reset()
+	_, err = io.Copy(hash, blob)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if got := hash.Sum32(); got != want {
+		t.Fatalf("got %d, want %d", got, want)
+	}
+
+	if err := blob.Close(); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := db.Close(); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestBlob_overflow(t *testing.T) {
+	t.Parallel()
+
+	db, err := sqlite3.Open(":memory:")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+
+	err = db.Exec(`CREATE TABLE IF NOT EXISTS test (col)`)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = db.Exec(`INSERT INTO test VALUES (zeroblob(1024))`)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	blob, err := db.OpenBlob("main", "test", "col", db.LastInsertRowID(), true)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer blob.Close()
+
+	n, err := blob.ReadFrom(rand.Reader)
+	if n != 1024 || !errors.Is(err, sqlite3.ERROR) {
+		t.Fatalf("got (%d, %v), want (0, ERROR)", n, err)
+	}
+
+	n, err = blob.ReadFrom(rand.Reader)
+	if n != 0 || !errors.Is(err, sqlite3.ERROR) {
+		t.Fatalf("got (%d, %v), want (0, ERROR)", n, err)
+	}
+
+	_, err = blob.Seek(-128, io.SeekEnd)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	n, err = blob.WriteTo(io.Discard)
+	if n != 128 || err != nil {
+		t.Fatalf("got (%d, %v), want (128, nil)", n, err)
+	}
+
+	n, err = blob.WriteTo(io.Discard)
+	if n != 0 || err != nil {
+		t.Fatalf("got (%d, %v), want (0, nil)", n, err)
+	}
+
+	if err := blob.Close(); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := db.Close(); err != nil {
+		t.Fatal(err)
+	}
+}
+
 func TestBlob_invalid(t *testing.T) {
 	t.Parallel()
 

tests/bradfitz/sql_test.go

@@ -126,7 +126,7 @@ func testTxQuery(t params) {
 		if r.Err() != nil {
 			t.Fatal(err)
 		}
-		t.Fatal("expected one rows")
+		t.Fatal("expected one row")
 	}
 
 	var name string

tests/conn_test.go

@@ -3,6 +3,9 @@ package tests
 import (
 	"context"
 	"errors"
+	"os"
+	"path/filepath"
+	"reflect"
 	"strings"
 	"testing"
 
@@ -13,7 +16,7 @@ import (
 func TestConn_Open_dir(t *testing.T) {
 	t.Parallel()
 
-	_, err := sqlite3.Open(".")
+	_, err := sqlite3.OpenFlags(".", 0)
 	if err == nil {
 		t.Fatal("want error")
 	}
@@ -22,6 +25,55 @@ func TestConn_Open_dir(t *testing.T) {
 	}
 }
 
+func TestConn_Open_notfound(t *testing.T) {
+	t.Parallel()
+
+	_, err := sqlite3.OpenFlags("test.db", sqlite3.OPEN_READONLY)
+	if err == nil {
+		t.Fatal("want error")
+	}
+	if !errors.Is(err, sqlite3.CANTOPEN) {
+		t.Errorf("got %v, want sqlite3.CANTOPEN", err)
+	}
+}
+
+func TestConn_Open_modeof(t *testing.T) {
+	t.Parallel()
+
+	dir := t.TempDir()
+	file := filepath.Join(dir, "test.db")
+	mode := filepath.Join(dir, "modeof.txt")
+
+	fd, err := os.OpenFile(mode, os.O_CREATE, 0624)
+	if err != nil {
+		t.Fatal(err)
+	}
+	fi, err := fd.Stat()
+	if err != nil {
+		t.Fatal(err)
+	}
+	fd.Close()
+
+	db, err := sqlite3.Open("file:" + file + "?modeof=" + mode)
+	if err != nil {
+		t.Fatal(err)
+	}
+	di, err := os.Stat(file)
+	if err != nil {
+		t.Fatal(err)
+	}
+	db.Close()
+
+	if di.Mode() != fi.Mode() {
+		t.Errorf("got %v, want %v", di.Mode(), fi.Mode())
+	}
+
+	_, err = sqlite3.Open("file:" + file + "?modeof=" + mode + "2")
+	if err == nil {
+		t.Fatal("want error")
+	}
+}
+
 func TestConn_Close(t *testing.T) {
 	var conn *sqlite3.Conn
 	conn.Close()
@@ -58,6 +110,41 @@ func TestConn_Close_BUSY(t *testing.T) {
 	}
 }
 
+func TestConn_Pragma(t *testing.T) {
+	t.Parallel()
+
+	db, err := sqlite3.Open("file::memory:?_pragma=busy_timeout(1000)")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+
+	got, err := db.Pragma("busy_timeout")
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := []string{"1000"}
+
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("got %v, want %v", got, want)
+	}
+
+	var serr *sqlite3.Error
+	_, err = db.Pragma("+")
+	if err == nil {
+		t.Error("want: error")
+	}
+	if !errors.As(err, &serr) {
+		t.Fatalf("got %T, want sqlite3.Error", err)
+	}
+	if rc := serr.Code(); rc != sqlite3.ERROR {
+		t.Errorf("got %d, want sqlite3.ERROR", rc)
+	}
+	if got := err.Error(); got != `sqlite3: SQL logic error: near "+": syntax error` {
+		t.Error("got message:", got)
+	}
+}
+
 func TestConn_SetInterrupt(t *testing.T) {
 	t.Parallel()
 
@@ -202,59 +289,3 @@ func TestConn_Prepare_invalid(t *testing.T) {
 		t.Error("got message:", got)
 	}
 }
-
-func TestConn_MustPrepare_empty(t *testing.T) {
-	t.Parallel()
-
-	db, err := sqlite3.Open(":memory:")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer db.Close()
-
-	defer func() { _ = recover() }()
-	_ = db.MustPrepare(``)
-	t.Error("want panic")
-}
-
-func TestConn_MustPrepare_tail(t *testing.T) {
-	t.Parallel()
-
-	db, err := sqlite3.Open(":memory:")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer db.Close()
-
-	defer func() { _ = recover() }()
-	_ = db.MustPrepare(`SELECT 1; -- HERE`)
-	t.Error("want panic")
-}
-
-func TestConn_MustPrepare_invalid(t *testing.T) {
-	t.Parallel()
-
-	db, err := sqlite3.Open(":memory:")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer db.Close()
-
-	defer func() { _ = recover() }()
-	_ = db.MustPrepare(`SELECT`)
-	t.Error("want panic")
-}
-
-func TestConn_Pragma(t *testing.T) {
-	t.Parallel()
-
-	db, err := sqlite3.Open(":memory:")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer db.Close()
-
-	defer func() { _ = recover() }()
-	_ = db.Pragma("encoding=''")
-	t.Error("want panic")
-}

tests/db_test.go

@@ -6,19 +6,24 @@ import (
 
 	"github.com/ncruces/go-sqlite3"
 	_ "github.com/ncruces/go-sqlite3/embed"
+	_ "github.com/ncruces/go-sqlite3/vfs/memdb"
 )
 
 func TestDB_memory(t *testing.T) {
+	t.Parallel()
 	testDB(t, ":memory:")
 }
 
 func TestDB_file(t *testing.T) {
+	t.Parallel()
 	testDB(t, filepath.Join(t.TempDir(), "test.db"))
 }
 
-func testDB(t *testing.T, name string) {
-	t.Parallel()
+func TestDB_vfs(t *testing.T) {
+	testDB(t, "file:test.db?vfs=memdb")
+}
 
+func testDB(t *testing.T, name string) {
 	db, err := sqlite3.Open(name)
 	if err != nil {
 		t.Fatal(err)

tests/driver_test.go

@@ -27,18 +27,32 @@ func TestDriver(t *testing.T) {
 	}
 	defer conn.Close()
 
-	_, err = conn.ExecContext(ctx,
+	res, err := conn.ExecContext(ctx,
 		`CREATE TABLE IF NOT EXISTS users (id INT, name VARCHAR(10))`)
 	if err != nil {
 		t.Fatal(err)
 	}
+	changes, err := res.RowsAffected()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if changes != 0 {
+		t.Errorf("got %d want 0", changes)
+	}
+	id, err := res.LastInsertId()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if id != 0 {
+		t.Errorf("got %d want 0", changes)
+	}
 
-	res, err := conn.ExecContext(ctx,
+	res, err = conn.ExecContext(ctx,
 		`INSERT INTO users (id, name) VALUES (0, 'go'), (1, 'zig'), (2, 'whatever')`)
 	if err != nil {
 		t.Fatal(err)
 	}
-	changes, err := res.RowsAffected()
+	changes, err = res.RowsAffected()
 	if err != nil {
 		t.Fatal(err)
 	}

tests/ext_test.go

@@ -0,0 +1,77 @@
+package tests
+
+import (
+	"testing"
+
+	"github.com/ncruces/go-sqlite3"
+)
+
+func Test_base64(t *testing.T) {
+	t.Parallel()
+
+	db, err := sqlite3.Open(":memory:")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+
+	// base64
+	stmt, _, err := db.Prepare(`SELECT base64('TWFueSBoYW5kcyBtYWtlIGxpZ2h0IHdvcmsu')`)
+	if err != nil {
+		t.Error(err)
+	}
+	defer stmt.Close()
+
+	if !stmt.Step() {
+		t.Fatal("expected one row")
+	}
+	if got := stmt.ColumnText(0); got != "Many hands make light work." {
+		t.Errorf("got %q", got)
+	}
+}
+
+func Test_decimal(t *testing.T) {
+	t.Parallel()
+
+	db, err := sqlite3.Open(":memory:")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+
+	stmt, _, err := db.Prepare(`SELECT decimal_add(decimal('0.1'), decimal('0.2')) = decimal('0.3')`)
+	if err != nil {
+		t.Error(err)
+	}
+	defer stmt.Close()
+
+	if !stmt.Step() {
+		t.Fatal("expected one row")
+	}
+	if !stmt.ColumnBool(0) {
+		t.Error("want true")
+	}
+}
+
+func Test_uint(t *testing.T) {
+	t.Parallel()
+
+	db, err := sqlite3.Open(":memory:")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+
+	stmt, _, err := db.Prepare(`SELECT 'z2' < 'z11' COLLATE UINT`)
+	if err != nil {
+		t.Error(err)
+	}
+	defer stmt.Close()
+
+	if !stmt.Step() {
+		t.Fatal("expected one row")
+	}
+	if !stmt.ColumnBool(0) {
+		t.Error("want true")
+	}
+}

tests/mptest/testdata/build.sh

@@ -1,26 +0,0 @@
-#!/usr/bin/env bash
-set -eo pipefail
-
-cd -P -- "$(dirname -- "$0")"
-
-if [ ! -f "mptest.c" ]; then
-	curl -sOL	"https://github.com/sqlite/sqlite/raw/master/mptest/mptest.c"
-	curl -sOL "https://github.com/sqlite/sqlite/raw/master/mptest/config01.test"
-  curl -sOL "https://github.com/sqlite/sqlite/raw/master/mptest/config02.test"
-  curl -sOL "https://github.com/sqlite/sqlite/raw/master/mptest/crash01.test"
-  curl -sOL "https://github.com/sqlite/sqlite/raw/master/mptest/crash02.subtest"
-  curl -sOL "https://github.com/sqlite/sqlite/raw/master/mptest/multiwrite01.test"
-fi
-
-zig cc --target=wasm32-wasi -flto -g0 -Os \
-  -o mptest.wasm main.c test.c \
-	-I../../../sqlite3 \
-	-mmutable-globals \
-	-mbulk-memory -mreference-types \
-	-mnontrapping-fptoint -msign-ext \
-	-D_HAVE_SQLITE_CONFIG_H \
-	-DSQLITE_DEFAULT_SYNCHRONOUS=0 \
-	-DSQLITE_DEFAULT_LOCKING_MODE=0 \
-	-DHAVE_USLEEP -DSQLITE_NO_SYNC \
-	-DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION \
-	-D_WASI_EMULATED_GETPID -lwasi-emulated-getpid

tests/mptest/testdata/main.c

@@ -1,22 +0,0 @@
-#include <stdbool.h>
-#include <stddef.h>
-
-#include "os.c"
-#include "qsort.c"
-#include "sqlite3.c"
-
-sqlite3_destructor_type malloc_destructor = &free;
-size_t sqlite3_interrupt_offset = offsetof(sqlite3, u1.isInterrupted);
-
-void __attribute__((constructor)) premain() { sqlite3_initialize(); }
-
-int sqlite3_enable_load_extension(sqlite3 *db, int onoff) { return SQLITE_OK; }
-
-void *sqlite3_trace(sqlite3 *db, void (*xTrace)(void *, const char *),
-                    void *pArg) {
-  return NULL;
-}
-
-int sqlite3_os_init() {
-  return sqlite3_vfs_register(os_vfs(), /*default=*/true);
-}

tests/mptest/testdata/mptest.wasm

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:3960b873a7dab969a66f7859d491cec0dd4e6c0c9f83eab449fb15ec5ebdfd8f
-size 1077281

tests/mptest/testdata/test.c

@@ -1,5 +0,0 @@
-#define unlink dont_unlink
-
-#include "mptest.c"
-
-int dont_unlink(const char *pathname) { return 0; }

tests/parallel/parallel_test.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/ncruces/go-sqlite3"
 	_ "github.com/ncruces/go-sqlite3/embed"
+	_ "github.com/ncruces/go-sqlite3/vfs/memdb"
 )
 
 func TestParallel(t *testing.T) {
@@ -21,7 +22,29 @@ func TestParallel(t *testing.T) {
 		iter = 5000
 	}
 
-	name := filepath.Join(t.TempDir(), "test.db")
+	name := "file:" +
+		filepath.Join(t.TempDir(), "test.db") +
+		"?_pragma=busy_timeout(10000)" +
+		"&_pragma=locking_mode(normal)" +
+		"&_pragma=journal_mode(truncate)" +
+		"&_pragma=synchronous(off)"
+	testParallel(t, name, iter)
+	testIntegrity(t, name)
+}
+
+func TestMemory(t *testing.T) {
+	var iter int
+	if testing.Short() {
+		iter = 1000
+	} else {
+		iter = 5000
+	}
+
+	name := "file:/test.db?vfs=memdb" +
+		"&_pragma=busy_timeout(10000)" +
+		"&_pragma=locking_mode(normal)" +
+		"&_pragma=journal_mode(memory)" +
+		"&_pragma=synchronous(off)"
 	testParallel(t, name, iter)
 	testIntegrity(t, name)
 }
@@ -31,8 +54,14 @@ func TestMultiProcess(t *testing.T) {
 		t.Skip("skipping in short mode")
 	}
 
-	name := filepath.Join(t.TempDir(), "test.db")
-	t.Setenv("TestMultiProcess_dbname", name)
+	file := filepath.Join(t.TempDir(), "test.db")
+	t.Setenv("TestMultiProcess_dbfile", file)
+
+	name := "file:" + file +
+		"?_pragma=busy_timeout(10000)" +
+		"&_pragma=locking_mode(normal)" +
+		"&_pragma=journal_mode(truncate)" +
+		"&_pragma=synchronous(off)"
 
 	cmd := exec.Command("go", "test", "-v", "-run", "TestChildProcess")
 	out, err := cmd.StdoutPipe()
@@ -57,11 +86,17 @@ func TestMultiProcess(t *testing.T) {
 }
 
 func TestChildProcess(t *testing.T) {
-	name := os.Getenv("TestMultiProcess_dbname")
-	if name == "" || testing.Short() {
+	file := os.Getenv("TestMultiProcess_dbfile")
+	if file == "" || testing.Short() {
 		t.SkipNow()
 	}
 
+	name := "file:" + file +
+		"?_pragma=busy_timeout(10000)" +
+		"&_pragma=locking_mode(normal)" +
+		"&_pragma=journal_mode(truncate)" +
+		"&_pragma=synchronous(off)"
+
 	testParallel(t, name, 1000)
 }
 
@@ -73,16 +108,6 @@ func testParallel(t *testing.T, name string, n int) {
 		}
 		defer db.Close()
 
-		err = db.Exec(`
-			PRAGMA busy_timeout=10000;
-			PRAGMA synchronous=off;
-			PRAGMA locking_mode=normal;
-			PRAGMA journal_mode=truncate;
-		`)
-		if err != nil {
-			return err
-		}
-
 		err = db.Exec(`CREATE TABLE IF NOT EXISTS users (id INT, name VARCHAR(10))`)
 		if err != nil {
 			return err

tests/time_test.go

@@ -40,7 +40,7 @@ func TestTimeFormat_Decode(t *testing.T) {
 	t.Parallel()
 
 	reference := time.Date(2013, 10, 7, 4, 23, 19, 120_000_000, time.FixedZone("", -4*3600))
-	reftime := time.Date(2000, 1, 1, 4, 23, 19, 120_000_000, time.FixedZone("", -4*3600))
+	refnodate := time.Date(2000, 01, 1, 4, 23, 19, 120_000_000, time.FixedZone("", -4*3600))
 
 	tests := []struct {
 		fmt       sqlite3.TimeFormat
@@ -89,14 +89,14 @@ func TestTimeFormat_Decode(t *testing.T) {
 		{sqlite3.TimeFormatAuto, "1381134199120000", reference, 0, false},
 		{sqlite3.TimeFormatAuto, "1381134199120000000", reference, 0, false},
 		{sqlite3.TimeFormatAuto, "2013-10-07 04:23:19.12-04:00", reference, 0, false},
-		{sqlite3.TimeFormatAuto, "04:23:19.12-04:00", reftime, 0, false},
+		{sqlite3.TimeFormatAuto, "04:23:19.12-04:00", refnodate, 0, false},
 		{sqlite3.TimeFormatAuto, "abc", time.Time{}, 0, true},
 		{sqlite3.TimeFormatAuto, false, time.Time{}, 0, true},
 
 		{sqlite3.TimeFormat3, "2013-10-07 04:23:19.12-04:00", reference, 0, false},
 		{sqlite3.TimeFormat3, "2013-10-07 08:23:19.12", reference, 0, false},
-		{sqlite3.TimeFormat9, "04:23:19.12-04:00", reftime, 0, false},
-		{sqlite3.TimeFormat9, "08:23:19.12", reftime, 0, false},
+		{sqlite3.TimeFormat9, "04:23:19.12-04:00", refnodate, 0, false},
+		{sqlite3.TimeFormat9, "08:23:19.12", refnodate, 0, false},
 		{sqlite3.TimeFormat3, false, time.Time{}, 0, true},
 		{sqlite3.TimeFormat9, false, time.Time{}, 0, true},
 
@@ -118,3 +118,52 @@ func TestTimeFormat_Decode(t *testing.T) {
 		})
 	}
 }
+
+func TestDB_timeCollation(t *testing.T) {
+	t.Parallel()
+
+	db, err := sqlite3.Open(":memory:")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+
+	err = db.Exec(`CREATE TABLE IF NOT EXISTS times (tstamp COLLATE TIME)`)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	stmt, _, err := db.Prepare(`INSERT INTO times VALUES (?), (?), (?)`)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer stmt.Close()
+
+	stmt.BindTime(1, time.Unix(0, 0).UTC(), sqlite3.TimeFormatDefault)
+	stmt.BindTime(2, time.Unix(0, -1).UTC(), sqlite3.TimeFormatDefault)
+	stmt.BindTime(3, time.Unix(0, +1).UTC(), sqlite3.TimeFormatDefault)
+	stmt.Step()
+
+	err = stmt.Close()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	stmt, _, err = db.Prepare(`SELECT tstamp FROM times ORDER BY tstamp`)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var t0 time.Time
+	for stmt.Step() {
+		t1 := stmt.ColumnTime(0, sqlite3.TimeFormatAuto)
+		if t0.After(t1) {
+			t.Errorf("got %v after %v", t0, t1)
+		}
+		t0 = t1
+	}
+	err = stmt.Close()
+	if err != nil {
+		t.Fatal(err)
+	}
+}

tests/tx_test.go

@@ -185,10 +185,10 @@ func TestConn_Transaction_interrupt(t *testing.T) {
 		t.Errorf("got %v, want sqlite3.INTERRUPT", err)
 	}
 
-	var nilErr error
-	tx.End(&nilErr)
-	if !errors.Is(nilErr, sqlite3.INTERRUPT) {
-		t.Errorf("got %v, want sqlite3.INTERRUPT", nilErr)
+	err = nil
+	tx.End(&err)
+	if !errors.Is(err, sqlite3.INTERRUPT) {
+		t.Errorf("got %v, want sqlite3.INTERRUPT", err)
 	}
 
 	db.SetInterrupt(context.Background())
@@ -210,6 +210,33 @@ func TestConn_Transaction_interrupt(t *testing.T) {
 	}
 }
 
+func TestConn_Transaction_interrupted(t *testing.T) {
+	t.Parallel()
+
+	db, err := sqlite3.Open(":memory:")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+
+	ctx, cancel := context.WithCancel(context.Background())
+	db.SetInterrupt(ctx)
+	cancel()
+
+	tx := db.Begin()
+
+	err = tx.Commit()
+	if !errors.Is(err, sqlite3.INTERRUPT) {
+		t.Errorf("got %v, want sqlite3.INTERRUPT", err)
+	}
+
+	err = nil
+	tx.End(&err)
+	if !errors.Is(err, sqlite3.INTERRUPT) {
+		t.Errorf("got %v, want sqlite3.INTERRUPT", err)
+	}
+}
+
 func TestConn_Transaction_rollback(t *testing.T) {
 	t.Parallel()
 
@@ -286,7 +313,7 @@ func TestConn_Savepoint_exec(t *testing.T) {
 	}
 
 	insert := func(succeed bool) (err error) {
-		defer db.Savepoint()(&err)
+		defer db.Savepoint().Release(&err)
 
 		err = db.Exec(`INSERT INTO test VALUES ('hello')`)
 		if err != nil {
@@ -344,7 +371,7 @@ func TestConn_Savepoint_panic(t *testing.T) {
 	}
 
 	panics := func() (err error) {
-		defer db.Savepoint()(&err)
+		defer db.Savepoint().Release(&err)
 
 		err = db.Exec(`INSERT INTO test VALUES ('hello')`)
 		if err != nil {
@@ -395,12 +422,12 @@ func TestConn_Savepoint_interrupt(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	release := db.Savepoint()
+	savept := db.Savepoint()
 	err = db.Exec(`INSERT INTO test VALUES (1)`)
 	if err != nil {
 		t.Fatal(err)
 	}
-	release(&err)
+	savept.Release(&err)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -408,19 +435,19 @@ func TestConn_Savepoint_interrupt(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	db.SetInterrupt(ctx)
 
-	release1 := db.Savepoint()
+	savept1 := db.Savepoint()
 	err = db.Exec(`INSERT INTO test VALUES (2)`)
 	if err != nil {
 		t.Fatal(err)
 	}
-	release2 := db.Savepoint()
+	savept2 := db.Savepoint()
 	err = db.Exec(`INSERT INTO test VALUES (3)`)
 	if err != nil {
 		t.Fatal(err)
 	}
 
 	cancel()
-	db.Savepoint()(&err)
+	db.Savepoint().Release(&err)
 	if !errors.Is(err, sqlite3.INTERRUPT) {
 		t.Errorf("got %v, want sqlite3.INTERRUPT", err)
 	}
@@ -431,15 +458,15 @@ func TestConn_Savepoint_interrupt(t *testing.T) {
 	}
 
 	err = context.Canceled
-	release2(&err)
+	savept2.Release(&err)
 	if err != context.Canceled {
 		t.Fatal(err)
 	}
 
-	var nilErr error
-	release1(&nilErr)
-	if !errors.Is(nilErr, sqlite3.INTERRUPT) {
-		t.Errorf("got %v, want sqlite3.INTERRUPT", nilErr)
+	err = nil
+	savept1.Release(&err)
+	if !errors.Is(err, sqlite3.INTERRUPT) {
+		t.Errorf("got %v, want sqlite3.INTERRUPT", err)
 	}
 
 	db.SetInterrupt(context.Background())
@@ -475,7 +502,7 @@ func TestConn_Savepoint_rollback(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	release := db.Savepoint()
+	savept := db.Savepoint()
 	err = db.Exec(`INSERT INTO test VALUES (1)`)
 	if err != nil {
 		t.Fatal(err)
@@ -484,7 +511,7 @@ func TestConn_Savepoint_rollback(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	release(&err)
+	savept.Release(&err)
 	if err != nil {
 		t.Fatal(err)
 	}

tests/vfs_test.go

@@ -0,0 +1,36 @@
+package tests
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/ncruces/go-sqlite3"
+	_ "github.com/ncruces/go-sqlite3/driver"
+	_ "github.com/ncruces/go-sqlite3/embed"
+	"github.com/ncruces/go-sqlite3/vfs/memdb"
+	"github.com/ncruces/go-sqlite3/vfs/readervfs"
+)
+
+func TestMemoryVFS_Open_notfound(t *testing.T) {
+	memdb.Delete("demo.db")
+
+	_, err := sqlite3.Open("file:/demo.db?vfs=memdb&mode=ro")
+	if err == nil {
+		t.Error("want error")
+	}
+	if !errors.Is(err, sqlite3.CANTOPEN) {
+		t.Errorf("got %v, want sqlite3.CANTOPEN", err)
+	}
+}
+
+func TestReaderVFS_Open_notfound(t *testing.T) {
+	readervfs.Delete("demo.db")
+
+	_, err := sqlite3.Open("file:demo.db?vfs=reader")
+	if err == nil {
+		t.Error("want error")
+	}
+	if !errors.Is(err, sqlite3.CANTOPEN) {
+		t.Errorf("got %v, want sqlite3.CANTOPEN", err)
+	}
+}

time.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/ncruces/go-sqlite3/internal/util"
 	"github.com/ncruces/julianday"
 )
 
@@ -62,13 +63,18 @@ const (
 // [TimeFormatDefault] and [TimeFormatAuto] encode using [time.RFC3339Nano],
 // with nanosecond accuracy, and preserving any timezone offset.
 //
-// This is the format used by the database/sql driver:
-// [database/sql.Row.Scan] is able to decode as [time.Time]
+// This is the format used by the [database/sql] driver:
+// [database/sql.Row.Scan] will decode as [time.Time]
 // values encoded with [time.RFC3339Nano].
 //
 // Time values encoded with [time.RFC3339Nano] cannot be sorted as strings
 // to produce a time-ordered sequence.
-// Use [TimeFormat7] for time-ordered encoding.
+//
+// Assuming that the time zones of the time values are the same (e.g., all in UTC),
+// and expressed using the same string (e.g., all "Z" or all "+00:00"),
+// use the TIME [collating sequence] to produce a time-ordered sequence.
+//
+// Otherwise, use [TimeFormat7] for time-ordered encoding.
 //
 // Formats [TimeFormat1] through [TimeFormat10]
 // convert time values to UTC before encoding.
@@ -78,6 +84,8 @@ const (
 // or an int64 for the other numeric formats.
 //
 // https://www.sqlite.org/lang_datefunc.html
+//
+// [collating sequence]: https://www.sqlite.org/datatype3.html#collating_sequences
 func (f TimeFormat) Encode(t time.Time) any {
 	switch f {
 	// Numeric formats
@@ -123,9 +131,9 @@ func (f TimeFormat) Encode(t time.Time) any {
 // [TimeFormatAuto] implements (and extends) the SQLite auto modifier.
 // Julian day numbers are safe to use for historical dates,
 // from 4712BC through 9999AD.
-// Unix timestamps (expressed in seconds, milliseconds, microseconds, or nanoseconds),
-// are safe to use for current events, from 1980 through at least 2260.
-// Unix timestamps before 1980 may be misinterpreted as julian day numbers,
+// Unix timestamps (expressed in seconds, milliseconds, microseconds, or nanoseconds)
+// are safe to use for current events, from at least 1980 through at least 2260.
+// Unix timestamps before 1980 and after 9999 may be misinterpreted as julian day numbers,
 // or have the wrong time unit.
 //
 // https://www.sqlite.org/lang_datefunc.html
@@ -141,7 +149,7 @@ func (f TimeFormat) Decode(v any) (time.Time, error) {
 		case int64:
 			return julianday.Time(v, 0), nil
 		default:
-			return time.Time{}, timeErr
+			return time.Time{}, util.TimeErr
 		}
 
 	case TimeFormatUnix, TimeFormatUnixFrac:
@@ -160,7 +168,7 @@ func (f TimeFormat) Decode(v any) (time.Time, error) {
 		case int64:
 			return time.Unix(v, 0), nil
 		default:
-			return time.Time{}, timeErr
+			return time.Time{}, util.TimeErr
 		}
 
 	case TimeFormatUnixMilli:
@@ -177,7 +185,7 @@ func (f TimeFormat) Decode(v any) (time.Time, error) {
 		case int64:
 			return time.UnixMilli(int64(v)), nil
 		default:
-			return time.Time{}, timeErr
+			return time.Time{}, util.TimeErr
 		}
 
 	case TimeFormatUnixMicro:
@@ -194,14 +202,14 @@ func (f TimeFormat) Decode(v any) (time.Time, error) {
 		case int64:
 			return time.UnixMicro(int64(v)), nil
 		default:
-			return time.Time{}, timeErr
+			return time.Time{}, util.TimeErr
 		}
 
 	case TimeFormatUnixNano:
 		if s, ok := v.(string); ok {
 			i, err := strconv.ParseInt(s, 10, 64)
 			if err != nil {
-				return time.Time{}, timeErr
+				return time.Time{}, util.TimeErr
 			}
 			v = i
 		}
@@ -211,7 +219,7 @@ func (f TimeFormat) Decode(v any) (time.Time, error) {
 		case int64:
 			return time.Unix(0, int64(v)), nil
 		default:
-			return time.Time{}, timeErr
+			return time.Time{}, util.TimeErr
 		}
 
 	// Special formats
@@ -281,7 +289,7 @@ func (f TimeFormat) Decode(v any) (time.Time, error) {
 			}
 			return TimeFormatUnixNano.Decode(v)
 		default:
-			return time.Time{}, timeErr
+			return time.Time{}, util.TimeErr
 		}
 
 	case
@@ -293,7 +301,7 @@ func (f TimeFormat) Decode(v any) (time.Time, error) {
 		TimeFormat7, TimeFormat7TZ:
 		s, ok := v.(string)
 		if !ok {
-			return time.Time{}, timeErr
+			return time.Time{}, util.TimeErr
 		}
 		return f.parseRelaxed(s)
 
@@ -303,7 +311,7 @@ func (f TimeFormat) Decode(v any) (time.Time, error) {
 		TimeFormat10, TimeFormat10TZ:
 		s, ok := v.(string)
 		if !ok {
-			return time.Time{}, timeErr
+			return time.Time{}, util.TimeErr
 		}
 		t, err := f.parseRelaxed(s)
 		return t.AddDate(2000, 0, 0), err
@@ -311,7 +319,7 @@ func (f TimeFormat) Decode(v any) (time.Time, error) {
 	default:
 		s, ok := v.(string)
 		if !ok {
-			return time.Time{}, timeErr
+			return time.Time{}, util.TimeErr
 		}
 		if f == "" {
 			f = time.RFC3339Nano

tx.go

@@ -4,10 +4,14 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"math/rand"
 	"runtime"
+	"strconv"
 )
 
 // Tx is an in-progress database transaction.
+//
+// https://www.sqlite.org/lang_transaction.html
 type Tx struct {
 	c *Conn
 }
@@ -16,8 +20,9 @@ type Tx struct {
 //
 // https://www.sqlite.org/lang_transaction.html
 func (c *Conn) Begin() Tx {
-	err := c.Exec(`BEGIN DEFERRED`)
-	if err != nil && !errors.Is(err, INTERRUPT) {
+	// BEGIN even if interrupted.
+	err := c.txExecInterrupted(`BEGIN DEFERRED`)
+	if err != nil {
 		panic(err)
 	}
 	return Tx{c}
@@ -64,21 +69,22 @@ func (tx Tx) End(errp *error) {
 		defer panic(recovered)
 	}
 
-	if tx.c.GetAutocommit() {
-		// There is nothing to commit/rollback.
-		return
-	}
-
 	if *errp == nil && recovered == nil {
 		// Success path.
+		if tx.c.GetAutocommit() { // There is nothing to commit.
+			return
+		}
 		*errp = tx.Commit()
 		if *errp == nil {
 			return
 		}
-		// Possible interrupt, fall through to the error path.
+		// Fall through to the error path.
 	}
 
 	// Error path.
+	if tx.c.GetAutocommit() { // There is nothing to rollback.
+		return
+	}
 	err := tx.Rollback()
 	if err != nil {
 		panic(err)
@@ -92,33 +98,28 @@ func (tx Tx) Commit() error {
 	return tx.c.Exec(`COMMIT`)
 }
 
-// Rollback rollsback the transaction.
+// Rollback rolls back the transaction,
+// even if the connection has been interrupted.
 //
 // https://www.sqlite.org/lang_transaction.html
 func (tx Tx) Rollback() error {
-	// ROLLBACK even if the connection has been interrupted.
-	old := tx.c.SetInterrupt(context.Background())
-	defer tx.c.SetInterrupt(old)
-	return tx.c.Exec(`ROLLBACK`)
+	return tx.c.txExecInterrupted(`ROLLBACK`)
 }
 
-// Savepoint creates a named SQLite transaction using SAVEPOINT.
-//
-// On success Savepoint returns a release func that will call either
-// RELEASE or ROLLBACK depending on whether the parameter *error
-// points to a nil or non-nil error.
-//
-// This is meant to be deferred:
-//
-//	func doWork(conn *sqlite3.Conn) (err error) {
-//		defer conn.Savepoint()(&err)
-//
-//		// ... do work in the transaction
-//	}
+// Savepoint is a marker within a transaction
+// that allows for partial rollback.
 //
 // https://www.sqlite.org/lang_savepoint.html
-func (c *Conn) Savepoint() (release func(*error)) {
-	name := "sqlite3.Savepoint" // names can be reused
+type Savepoint struct {
+	c    *Conn
+	name string
+}
+
+// Savepoint establishes a new transaction savepoint.
+//
+// https://www.sqlite.org/lang_savepoint.html
+func (c *Conn) Savepoint() Savepoint {
+	name := "sqlite3.Savepoint"
 	var pc [1]uintptr
 	if n := runtime.Callers(2, pc[:]); n > 0 {
 		frames := runtime.CallersFrames(pc[:n])
@@ -127,52 +128,75 @@ func (c *Conn) Savepoint() (release func(*error)) {
 			name = frame.Function
 		}
 	}
+	// Names can be reused; this makes catching bugs more likely.
+	name += "#" + strconv.Itoa(int(rand.Int31()))
 
-	err := c.Exec(fmt.Sprintf("SAVEPOINT %q;", name))
+	err := c.txExecInterrupted(fmt.Sprintf("SAVEPOINT %q;", name))
 	if err != nil {
-		if errors.Is(err, INTERRUPT) {
-			return func(errp *error) {
-				if *errp == nil {
-					*errp = err
-				}
-			}
-		}
 		panic(err)
 	}
+	return Savepoint{c: c, name: name}
+}
 
-	return func(errp *error) {
-		recovered := recover()
-		if recovered != nil {
-			defer panic(recovered)
-		}
+// Release releases the savepoint rolling back any changes
+// if *error points to a non-nil error.
+//
+// This is meant to be deferred:
+//
+//	func doWork(conn *sqlite3.Conn) (err error) {
+//		savept := conn.Savepoint()
+//		defer savept.Release(&err)
+//
+//		// ... do work in the transaction
+//	}
+func (s Savepoint) Release(errp *error) {
+	recovered := recover()
+	if recovered != nil {
+		defer panic(recovered)
+	}
 
-		if c.GetAutocommit() {
-			// There is nothing to commit/rollback.
+	if *errp == nil && recovered == nil {
+		// Success path.
+		if s.c.GetAutocommit() { // There is nothing to commit.
 			return
 		}
-
-		if *errp == nil && recovered == nil {
-			// Success path.
-			// RELEASE the savepoint successfully.
-			*errp = c.Exec(fmt.Sprintf("RELEASE %q;", name))
-			if *errp == nil {
-				return
-			}
-			// Possible interrupt, fall through to the error path.
+		*errp = s.c.Exec(fmt.Sprintf("RELEASE %q;", s.name))
+		if *errp == nil {
+			return
 		}
+		// Fall through to the error path.
+	}
 
-		// Error path.
-		// Always ROLLBACK even if the connection has been interrupted.
-		old := c.SetInterrupt(context.Background())
-		defer c.SetInterrupt(old)
-
-		err := c.Exec(fmt.Sprintf("ROLLBACK TO %q;", name))
-		if err != nil {
-			panic(err)
-		}
-		err = c.Exec(fmt.Sprintf("RELEASE %q;", name))
-		if err != nil {
-			panic(err)
-		}
+	// Error path.
+	if s.c.GetAutocommit() { // There is nothing to rollback.
+		return
+	}
+	// ROLLBACK and RELEASE even if interrupted.
+	err := s.c.txExecInterrupted(fmt.Sprintf(`
+		ROLLBACK TO %[1]q;
+		RELEASE %[1]q;
+	`, s.name))
+	if err != nil {
+		panic(err)
 	}
 }
+
+// Rollback rolls the transaction back to the savepoint,
+// even if the connection has been interrupted.
+// Rollback does not release the savepoint.
+//
+// https://www.sqlite.org/lang_transaction.html
+func (s Savepoint) Rollback() error {
+	// ROLLBACK even if interrupted.
+	return s.c.txExecInterrupted(fmt.Sprintf("ROLLBACK TO %q;", s.name))
+}
+
+func (c *Conn) txExecInterrupted(sql string) error {
+	err := c.Exec(sql)
+	if errors.Is(err, INTERRUPT) {
+		old := c.SetInterrupt(context.Background())
+		defer c.SetInterrupt(old)
+		err = c.Exec(sql)
+	}
+	return err
+}

vfs.go

@@ -1,348 +0,0 @@
-package sqlite3
-
-import (
-	"context"
-	"crypto/rand"
-	"errors"
-	"io"
-	"io/fs"
-	"os"
-	"path/filepath"
-	"runtime"
-	"syscall"
-	"time"
-
-	"github.com/ncruces/julianday"
-	"github.com/tetratelabs/wazero"
-	"github.com/tetratelabs/wazero/api"
-	"github.com/tetratelabs/wazero/sys"
-)
-
-func vfsInstantiate(ctx context.Context, r wazero.Runtime) {
-	wasi := r.NewHostModuleBuilder("wasi_snapshot_preview1")
-	wasi.NewFunctionBuilder().WithFunc(vfsExit).Export("proc_exit")
-	_, err := wasi.Instantiate(ctx)
-	if err != nil {
-		panic(err)
-	}
-
-	env := vfsNewEnvModuleBuilder(r)
-	_, err = env.Instantiate(ctx)
-	if err != nil {
-		panic(err)
-	}
-}
-
-func vfsNewEnvModuleBuilder(r wazero.Runtime) wazero.HostModuleBuilder {
-	env := r.NewHostModuleBuilder("env")
-	env.NewFunctionBuilder().WithFunc(vfsLocaltime).Export("os_localtime")
-	env.NewFunctionBuilder().WithFunc(vfsRandomness).Export("os_randomness")
-	env.NewFunctionBuilder().WithFunc(vfsSleep).Export("os_sleep")
-	env.NewFunctionBuilder().WithFunc(vfsCurrentTime).Export("os_current_time")
-	env.NewFunctionBuilder().WithFunc(vfsCurrentTime64).Export("os_current_time_64")
-	env.NewFunctionBuilder().WithFunc(vfsFullPathname).Export("os_full_pathname")
-	env.NewFunctionBuilder().WithFunc(vfsDelete).Export("os_delete")
-	env.NewFunctionBuilder().WithFunc(vfsAccess).Export("os_access")
-	env.NewFunctionBuilder().WithFunc(vfsOpen).Export("os_open")
-	env.NewFunctionBuilder().WithFunc(vfsClose).Export("os_close")
-	env.NewFunctionBuilder().WithFunc(vfsRead).Export("os_read")
-	env.NewFunctionBuilder().WithFunc(vfsWrite).Export("os_write")
-	env.NewFunctionBuilder().WithFunc(vfsTruncate).Export("os_truncate")
-	env.NewFunctionBuilder().WithFunc(vfsSync).Export("os_sync")
-	env.NewFunctionBuilder().WithFunc(vfsFileSize).Export("os_file_size")
-	env.NewFunctionBuilder().WithFunc(vfsLock).Export("os_lock")
-	env.NewFunctionBuilder().WithFunc(vfsUnlock).Export("os_unlock")
-	env.NewFunctionBuilder().WithFunc(vfsCheckReservedLock).Export("os_check_reserved_lock")
-	env.NewFunctionBuilder().WithFunc(vfsFileControl).Export("os_file_control")
-	return env
-}
-
-// Poor man's namespaces.
-const (
-	vfsOS   vfsOSMethods   = false
-	vfsFile vfsFileMethods = false
-)
-
-type (
-	vfsOSMethods   bool
-	vfsFileMethods bool
-)
-
-type vfsKey struct{}
-type vfsState struct {
-	files []*os.File
-}
-
-func vfsContext(ctx context.Context) (context.Context, io.Closer) {
-	vfs := &vfsState{}
-	return context.WithValue(ctx, vfsKey{}, vfs), vfs
-}
-
-func (vfs *vfsState) Close() error {
-	for _, f := range vfs.files {
-		if f != nil {
-			f.Close()
-		}
-	}
-	vfs.files = nil
-	return nil
-}
-
-func vfsExit(ctx context.Context, mod api.Module, exitCode uint32) {
-	// Ensure other callers see the exit code.
-	_ = mod.CloseWithExitCode(ctx, exitCode)
-	// Prevent any code from executing after this function.
-	panic(sys.NewExitError(mod.Name(), exitCode))
-}
-
-func vfsLocaltime(ctx context.Context, mod api.Module, t uint64, pTm uint32) uint32 {
-	tm := time.Unix(int64(t), 0)
-	var isdst int
-	if tm.IsDST() {
-		isdst = 1
-	}
-
-	// https://pubs.opengroup.org/onlinepubs/7908799/xsh/time.h.html
-	mem := memory{mod}
-	mem.writeUint32(pTm+0*ptrlen, uint32(tm.Second()))
-	mem.writeUint32(pTm+1*ptrlen, uint32(tm.Minute()))
-	mem.writeUint32(pTm+2*ptrlen, uint32(tm.Hour()))
-	mem.writeUint32(pTm+3*ptrlen, uint32(tm.Day()))
-	mem.writeUint32(pTm+4*ptrlen, uint32(tm.Month()-time.January))
-	mem.writeUint32(pTm+5*ptrlen, uint32(tm.Year()-1900))
-	mem.writeUint32(pTm+6*ptrlen, uint32(tm.Weekday()-time.Sunday))
-	mem.writeUint32(pTm+7*ptrlen, uint32(tm.YearDay()-1))
-	mem.writeUint32(pTm+8*ptrlen, uint32(isdst))
-	return _OK
-}
-
-func vfsRandomness(ctx context.Context, mod api.Module, pVfs, nByte, zByte uint32) uint32 {
-	mem := memory{mod}.view(zByte, uint64(nByte))
-	n, _ := rand.Reader.Read(mem)
-	return uint32(n)
-}
-
-func vfsSleep(ctx context.Context, pVfs, nMicro uint32) uint32 {
-	time.Sleep(time.Duration(nMicro) * time.Microsecond)
-	return _OK
-}
-
-func vfsCurrentTime(ctx context.Context, mod api.Module, pVfs, prNow uint32) uint32 {
-	day := julianday.Float(time.Now())
-	memory{mod}.writeFloat64(prNow, day)
-	return _OK
-}
-
-func vfsCurrentTime64(ctx context.Context, mod api.Module, pVfs, piNow uint32) uint32 {
-	day, nsec := julianday.Date(time.Now())
-	msec := day*86_400_000 + nsec/1_000_000
-	memory{mod}.writeUint64(piNow, uint64(msec))
-	return _OK
-}
-
-func vfsFullPathname(ctx context.Context, mod api.Module, pVfs, zRelative, nFull, zFull uint32) uint32 {
-	rel := memory{mod}.readString(zRelative, _MAX_PATHNAME)
-	abs, err := filepath.Abs(rel)
-	if err != nil {
-		return uint32(IOERR)
-	}
-
-	// Consider either using [filepath.EvalSymlinks] to canonicalize the path (as the Unix VFS does).
-	// Or using [os.Readlink] to resolve a symbolic link (as the Unix VFS did).
-	// This might be buggy on Windows (the Windows VFS doesn't try).
-
-	size := uint64(len(abs) + 1)
-	if size > uint64(nFull) {
-		return uint32(CANTOPEN_FULLPATH)
-	}
-	mem := memory{mod}.view(zFull, size)
-
-	mem[len(abs)] = 0
-	copy(mem, abs)
-	return _OK
-}
-
-func vfsDelete(ctx context.Context, mod api.Module, pVfs, zPath, syncDir uint32) uint32 {
-	path := memory{mod}.readString(zPath, _MAX_PATHNAME)
-	err := os.Remove(path)
-	if errors.Is(err, fs.ErrNotExist) {
-		return _OK
-	}
-	if err != nil {
-		return uint32(IOERR_DELETE)
-	}
-	if runtime.GOOS != "windows" && syncDir != 0 {
-		f, err := os.Open(filepath.Dir(path))
-		if err == nil {
-			err = f.Sync()
-			f.Close()
-		}
-		if err != nil {
-			return uint32(IOERR_DELETE)
-		}
-	}
-	return _OK
-}
-
-func vfsAccess(ctx context.Context, mod api.Module, pVfs, zPath uint32, flags _AccessFlag, pResOut uint32) uint32 {
-	// Consider using [syscall.Access] for [ACCESS_READWRITE]/[ACCESS_READ]
-	// (as the Unix VFS does).
-
-	path := memory{mod}.readString(zPath, _MAX_PATHNAME)
-	fi, err := os.Stat(path)
-
-	var res uint32
-	switch {
-	case flags == _ACCESS_EXISTS:
-		switch {
-		case err == nil:
-			res = 1
-		case errors.Is(err, fs.ErrNotExist):
-			res = 0
-		default:
-			return uint32(IOERR_ACCESS)
-		}
-
-	case err == nil:
-		var want fs.FileMode = syscall.S_IRUSR
-		if flags == _ACCESS_READWRITE {
-			want |= syscall.S_IWUSR
-		}
-		if fi.IsDir() {
-			want |= syscall.S_IXUSR
-		}
-		if fi.Mode()&want == want {
-			res = 1
-		} else {
-			res = 0
-		}
-
-	case errors.Is(err, fs.ErrPermission):
-		res = 0
-
-	default:
-		return uint32(IOERR_ACCESS)
-	}
-
-	memory{mod}.writeUint32(pResOut, res)
-	return _OK
-}
-
-func vfsOpen(ctx context.Context, mod api.Module, pVfs, zName, pFile uint32, flags OpenFlag, pOutFlags uint32) uint32 {
-	var oflags int
-	if flags&OPEN_EXCLUSIVE != 0 {
-		oflags |= os.O_EXCL
-	}
-	if flags&OPEN_CREATE != 0 {
-		oflags |= os.O_CREATE
-	}
-	if flags&OPEN_READONLY != 0 {
-		oflags |= os.O_RDONLY
-	}
-	if flags&OPEN_READWRITE != 0 {
-		oflags |= os.O_RDWR
-	}
-
-	var err error
-	var file *os.File
-	if zName == 0 {
-		file, err = os.CreateTemp("", "*.db")
-	} else {
-		name := memory{mod}.readString(zName, _MAX_PATHNAME)
-		file, err = os.OpenFile(name, oflags, 0600)
-	}
-	if err != nil {
-		return uint32(CANTOPEN)
-	}
-
-	if flags&OPEN_DELETEONCLOSE != 0 {
-		vfsOS.DeleteOnClose(file)
-	}
-
-	vfsFile.Open(ctx, mod, pFile, file)
-
-	if pOutFlags != 0 {
-		memory{mod}.writeUint32(pOutFlags, uint32(flags))
-	}
-	return _OK
-}
-
-func vfsClose(ctx context.Context, mod api.Module, pFile uint32) uint32 {
-	err := vfsFile.Close(ctx, mod, pFile)
-	if err != nil {
-		return uint32(IOERR_CLOSE)
-	}
-	return _OK
-}
-
-func vfsRead(ctx context.Context, mod api.Module, pFile, zBuf, iAmt uint32, iOfst uint64) uint32 {
-	buf := memory{mod}.view(zBuf, uint64(iAmt))
-
-	file := vfsFile.GetOS(ctx, mod, pFile)
-	n, err := file.ReadAt(buf, int64(iOfst))
-	if n == int(iAmt) {
-		return _OK
-	}
-	if n == 0 && err != io.EOF {
-		return uint32(IOERR_READ)
-	}
-	for i := range buf[n:] {
-		buf[n+i] = 0
-	}
-	return uint32(IOERR_SHORT_READ)
-}
-
-func vfsWrite(ctx context.Context, mod api.Module, pFile, zBuf, iAmt uint32, iOfst uint64) uint32 {
-	buf := memory{mod}.view(zBuf, uint64(iAmt))
-
-	file := vfsFile.GetOS(ctx, mod, pFile)
-	_, err := file.WriteAt(buf, int64(iOfst))
-	if err != nil {
-		return uint32(IOERR_WRITE)
-	}
-	return _OK
-}
-
-func vfsTruncate(ctx context.Context, mod api.Module, pFile uint32, nByte uint64) uint32 {
-	file := vfsFile.GetOS(ctx, mod, pFile)
-	err := file.Truncate(int64(nByte))
-	if err != nil {
-		return uint32(IOERR_TRUNCATE)
-	}
-	return _OK
-}
-
-func vfsSync(ctx context.Context, mod api.Module, pFile, flags uint32) uint32 {
-	file := vfsFile.GetOS(ctx, mod, pFile)
-	err := file.Sync()
-	if err != nil {
-		return uint32(IOERR_FSYNC)
-	}
-	return _OK
-}
-
-func vfsFileSize(ctx context.Context, mod api.Module, pFile, pSize uint32) uint32 {
-	// This uses [os.File.Seek] because we don't care about the offset for reading/writing.
-	// But consider using [os.File.Stat] instead (as other VFSes do).
-
-	file := vfsFile.GetOS(ctx, mod, pFile)
-	off, err := file.Seek(0, io.SeekEnd)
-	if err != nil {
-		return uint32(IOERR_SEEK)
-	}
-
-	memory{mod}.writeUint64(pSize, uint64(off))
-	return _OK
-}
-
-func vfsFileControl(ctx context.Context, pFile, op, pArg uint32) uint32 {
-	// SQLite calls vfsFileControl with these opcodes:
-	//  SQLITE_FCNTL_SIZE_HINT
-	//  SQLITE_FCNTL_PRAGMA
-	//  SQLITE_FCNTL_BUSYHANDLER
-	//  SQLITE_FCNTL_HAS_MOVED
-	//  SQLITE_FCNTL_SYNC
-	//  SQLITE_FCNTL_COMMIT_PHASETWO
-	//  SQLITE_FCNTL_PDB
-	return uint32(NOTFOUND)
-}

vfs/README.md

@@ -0,0 +1,9 @@
+# Go SQLite VFS API
+
+This package implements the SQLite [OS Interface](https://www.sqlite.org/vfs.html) (aka VFS).
+
+It replaces the default VFS with a pure Go implementation,
+that is tested on Linux, macOS and Windows,
+but which should also work on illumos and the various BSDs.
+
+It also exposes interfaces that should allow you to implement your own custom VFSes.

vfs/api.go

@@ -0,0 +1,103 @@
+// Package vfs wraps the C SQLite VFS API.
+package vfs
+
+import "net/url"
+
+// A VFS defines the interface between the SQLite core and the underlying operating system.
+//
+// Use sqlite3.ErrorCode or sqlite3.ExtendedErrorCode to return specific error codes to SQLite.
+//
+// https://www.sqlite.org/c3ref/vfs.html
+type VFS interface {
+	Open(name string, flags OpenFlag) (File, OpenFlag, error)
+	Delete(name string, syncDir bool) error
+	Access(name string, flags AccessFlag) (bool, error)
+	FullPathname(name string) (string, error)
+}
+
+// VFSParams extends VFS to with the ability to handle URI parameters
+// through the OpenParams method.
+//
+// https://www.sqlite.org/c3ref/uri_boolean.html
+type VFSParams interface {
+	VFS
+	OpenParams(name string, flags OpenFlag, params url.Values) (File, OpenFlag, error)
+}
+
+// A File represents an open file in the OS interface layer.
+//
+// Use sqlite3.ErrorCode or sqlite3.ExtendedErrorCode to return specific error codes to SQLite.
+// In particular, sqlite3.BUSY is necessary to correctly implement lock methods.
+//
+// https://www.sqlite.org/c3ref/io_methods.html
+type File interface {
+	Close() error
+	ReadAt(p []byte, off int64) (n int, err error)
+	WriteAt(p []byte, off int64) (n int, err error)
+	Truncate(size int64) error
+	Sync(flags SyncFlag) error
+	Size() (int64, error)
+	Lock(lock LockLevel) error
+	Unlock(lock LockLevel) error
+	CheckReservedLock() (bool, error)
+	SectorSize() int
+	DeviceCharacteristics() DeviceCharacteristic
+}
+
+// FileLockState extends File to implement the
+// SQLITE_FCNTL_LOCKSTATE file control opcode.
+//
+// https://www.sqlite.org/c3ref/c_fcntl_begin_atomic_write.html
+type FileLockState interface {
+	File
+	LockState() LockLevel
+}
+
+// FileSizeHint extends File to implement the
+// SQLITE_FCNTL_SIZE_HINT file control opcode.
+//
+// https://www.sqlite.org/c3ref/c_fcntl_begin_atomic_write.html
+type FileSizeHint interface {
+	File
+	SizeHint(size int64) error
+}
+
+// FileHasMoved extends File to implement the
+// SQLITE_FCNTL_HAS_MOVED file control opcode.
+//
+// https://www.sqlite.org/c3ref/c_fcntl_begin_atomic_write.html
+type FileHasMoved interface {
+	File
+	HasMoved() (bool, error)
+}
+
+// FilePowersafeOverwrite extends File to implement the
+// SQLITE_FCNTL_POWERSAFE_OVERWRITE file control opcode.
+//
+// https://www.sqlite.org/c3ref/c_fcntl_begin_atomic_write.html
+type FilePowersafeOverwrite interface {
+	File
+	PowersafeOverwrite() bool
+	SetPowersafeOverwrite(bool)
+}
+
+// FilePowersafeOverwrite extends File to implement the
+// SQLITE_FCNTL_COMMIT_PHASETWO file control opcode.
+//
+// https://www.sqlite.org/c3ref/c_fcntl_begin_atomic_write.html
+type FileCommitPhaseTwo interface {
+	File
+	CommitPhaseTwo() error
+}
+
+// FileBatchAtomicWrite extends File to implement the
+// SQLITE_FCNTL_BEGIN_ATOMIC_WRITE, SQLITE_FCNTL_COMMIT_ATOMIC_WRITE
+// and SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE file control opcodes.
+//
+// https://www.sqlite.org/c3ref/c_fcntl_begin_atomic_write.html
+type FileBatchAtomicWrite interface {
+	File
+	BeginAtomicWrite() error
+	CommitAtomicWrite() error
+	RollbackAtomicWrite() error
+}

vfs/const.go

@@ -0,0 +1,215 @@
+package vfs
+
+import "github.com/ncruces/go-sqlite3/internal/util"
+
+const (
+	_MAX_STRING          = 512 // Used for short strings: names, error messages…
+	_MAX_PATHNAME        = 512
+	_DEFAULT_SECTOR_SIZE = 4096
+)
+
+// https://www.sqlite.org/rescode.html
+type _ErrorCode uint32
+
+func (e _ErrorCode) Error() string {
+	return util.ErrorCodeString(uint32(e))
+}
+
+const (
+	_OK                      _ErrorCode = util.OK
+	_PERM                    _ErrorCode = util.PERM
+	_BUSY                    _ErrorCode = util.BUSY
+	_READONLY                _ErrorCode = util.READONLY
+	_IOERR                   _ErrorCode = util.IOERR
+	_NOTFOUND                _ErrorCode = util.NOTFOUND
+	_CANTOPEN                _ErrorCode = util.CANTOPEN
+	_IOERR_READ              _ErrorCode = util.IOERR_READ
+	_IOERR_SHORT_READ        _ErrorCode = util.IOERR_SHORT_READ
+	_IOERR_WRITE             _ErrorCode = util.IOERR_WRITE
+	_IOERR_FSYNC             _ErrorCode = util.IOERR_FSYNC
+	_IOERR_DIR_FSYNC         _ErrorCode = util.IOERR_DIR_FSYNC
+	_IOERR_TRUNCATE          _ErrorCode = util.IOERR_TRUNCATE
+	_IOERR_FSTAT             _ErrorCode = util.IOERR_FSTAT
+	_IOERR_UNLOCK            _ErrorCode = util.IOERR_UNLOCK
+	_IOERR_RDLOCK            _ErrorCode = util.IOERR_RDLOCK
+	_IOERR_DELETE            _ErrorCode = util.IOERR_DELETE
+	_IOERR_ACCESS            _ErrorCode = util.IOERR_ACCESS
+	_IOERR_CHECKRESERVEDLOCK _ErrorCode = util.IOERR_CHECKRESERVEDLOCK
+	_IOERR_LOCK              _ErrorCode = util.IOERR_LOCK
+	_IOERR_CLOSE             _ErrorCode = util.IOERR_CLOSE
+	_IOERR_SEEK              _ErrorCode = util.IOERR_SEEK
+	_IOERR_DELETE_NOENT      _ErrorCode = util.IOERR_DELETE_NOENT
+	_IOERR_BEGIN_ATOMIC      _ErrorCode = util.IOERR_BEGIN_ATOMIC
+	_IOERR_COMMIT_ATOMIC     _ErrorCode = util.IOERR_COMMIT_ATOMIC
+	_IOERR_ROLLBACK_ATOMIC   _ErrorCode = util.IOERR_ROLLBACK_ATOMIC
+	_CANTOPEN_FULLPATH       _ErrorCode = util.CANTOPEN_FULLPATH
+	_CANTOPEN_ISDIR          _ErrorCode = util.CANTOPEN_ISDIR
+	_OK_SYMLINK              _ErrorCode = util.OK_SYMLINK
+)
+
+// OpenFlag is a flag for the [VFS] Open method.
+//
+// https://www.sqlite.org/c3ref/c_open_autoproxy.html
+type OpenFlag uint32
+
+const (
+	OPEN_READONLY      OpenFlag = 0x00000001 /* Ok for sqlite3_open_v2() */
+	OPEN_READWRITE     OpenFlag = 0x00000002 /* Ok for sqlite3_open_v2() */
+	OPEN_CREATE        OpenFlag = 0x00000004 /* Ok for sqlite3_open_v2() */
+	OPEN_DELETEONCLOSE OpenFlag = 0x00000008 /* VFS only */
+	OPEN_EXCLUSIVE     OpenFlag = 0x00000010 /* VFS only */
+	OPEN_AUTOPROXY     OpenFlag = 0x00000020 /* VFS only */
+	OPEN_URI           OpenFlag = 0x00000040 /* Ok for sqlite3_open_v2() */
+	OPEN_MEMORY        OpenFlag = 0x00000080 /* Ok for sqlite3_open_v2() */
+	OPEN_MAIN_DB       OpenFlag = 0x00000100 /* VFS only */
+	OPEN_TEMP_DB       OpenFlag = 0x00000200 /* VFS only */
+	OPEN_TRANSIENT_DB  OpenFlag = 0x00000400 /* VFS only */
+	OPEN_MAIN_JOURNAL  OpenFlag = 0x00000800 /* VFS only */
+	OPEN_TEMP_JOURNAL  OpenFlag = 0x00001000 /* VFS only */
+	OPEN_SUBJOURNAL    OpenFlag = 0x00002000 /* VFS only */
+	OPEN_SUPER_JOURNAL OpenFlag = 0x00004000 /* VFS only */
+	OPEN_NOMUTEX       OpenFlag = 0x00008000 /* Ok for sqlite3_open_v2() */
+	OPEN_FULLMUTEX     OpenFlag = 0x00010000 /* Ok for sqlite3_open_v2() */
+	OPEN_SHAREDCACHE   OpenFlag = 0x00020000 /* Ok for sqlite3_open_v2() */
+	OPEN_PRIVATECACHE  OpenFlag = 0x00040000 /* Ok for sqlite3_open_v2() */
+	OPEN_WAL           OpenFlag = 0x00080000 /* VFS only */
+	OPEN_NOFOLLOW      OpenFlag = 0x01000000 /* Ok for sqlite3_open_v2() */
+)
+
+// AccessFlag is a flag for the [VFS] Access method.
+//
+// https://www.sqlite.org/c3ref/c_access_exists.html
+type AccessFlag uint32
+
+const (
+	ACCESS_EXISTS    AccessFlag = 0
+	ACCESS_READWRITE AccessFlag = 1 /* Used by PRAGMA temp_store_directory */
+	ACCESS_READ      AccessFlag = 2 /* Unused */
+)
+
+// SyncFlag is a flag for the [File] Sync method.
+//
+// https://www.sqlite.org/c3ref/c_sync_dataonly.html
+type SyncFlag uint32
+
+const (
+	SYNC_NORMAL   SyncFlag = 0x00002
+	SYNC_FULL     SyncFlag = 0x00003
+	SYNC_DATAONLY SyncFlag = 0x00010
+)
+
+// LockLevel is a value used with [File] Lock and Unlock methods.
+//
+// https://www.sqlite.org/c3ref/c_lock_exclusive.html
+type LockLevel uint32
+
+const (
+	// No locks are held on the database.
+	// The database may be neither read nor written.
+	// Any internally cached data is considered suspect and subject to
+	// verification against the database file before being used.
+	// Other processes can read or write the database as their own locking
+	// states permit.
+	// This is the default state.
+	LOCK_NONE LockLevel = 0 /* xUnlock() only */
+
+	// The database may be read but not written.
+	// Any number of processes can hold SHARED locks at the same time,
+	// hence there can be many simultaneous readers.
+	// But no other thread or process is allowed to write to the database file
+	// while one or more SHARED locks are active.
+	LOCK_SHARED LockLevel = 1 /* xLock() or xUnlock() */
+
+	// A RESERVED lock means that the process is planning on writing to the
+	// database file at some point in the future but that it is currently just
+	// reading from the file.
+	// Only a single RESERVED lock may be active at one time,
+	// though multiple SHARED locks can coexist with a single RESERVED lock.
+	// RESERVED differs from PENDING in that new SHARED locks can be acquired
+	// while there is a RESERVED lock.
+	LOCK_RESERVED LockLevel = 2 /* xLock() only */
+
+	// A PENDING lock means that the process holding the lock wants to write to
+	// the database as soon as possible and is just waiting on all current
+	// SHARED locks to clear so that it can get an EXCLUSIVE lock.
+	// No new SHARED locks are permitted against the database if a PENDING lock
+	// is active, though existing SHARED locks are allowed to continue.
+	LOCK_PENDING LockLevel = 3 /* internal use only */
+
+	// An EXCLUSIVE lock is needed in order to write to the database file.
+	// Only one EXCLUSIVE lock is allowed on the file and no other locks of any
+	// kind are allowed to coexist with an EXCLUSIVE lock.
+	// In order to maximize concurrency, SQLite works to minimize the amount of
+	// time that EXCLUSIVE locks are held.
+	LOCK_EXCLUSIVE LockLevel = 4 /* xLock() only */
+)
+
+// DeviceCharacteristic is a flag retuned by the [File] DeviceCharacteristics method.
+//
+// https://www.sqlite.org/c3ref/c_iocap_atomic.html
+type DeviceCharacteristic uint32
+
+const (
+	IOCAP_ATOMIC                DeviceCharacteristic = 0x00000001
+	IOCAP_ATOMIC512             DeviceCharacteristic = 0x00000002
+	IOCAP_ATOMIC1K              DeviceCharacteristic = 0x00000004
+	IOCAP_ATOMIC2K              DeviceCharacteristic = 0x00000008
+	IOCAP_ATOMIC4K              DeviceCharacteristic = 0x00000010
+	IOCAP_ATOMIC8K              DeviceCharacteristic = 0x00000020
+	IOCAP_ATOMIC16K             DeviceCharacteristic = 0x00000040
+	IOCAP_ATOMIC32K             DeviceCharacteristic = 0x00000080
+	IOCAP_ATOMIC64K             DeviceCharacteristic = 0x00000100
+	IOCAP_SAFE_APPEND           DeviceCharacteristic = 0x00000200
+	IOCAP_SEQUENTIAL            DeviceCharacteristic = 0x00000400
+	IOCAP_UNDELETABLE_WHEN_OPEN DeviceCharacteristic = 0x00000800
+	IOCAP_POWERSAFE_OVERWRITE   DeviceCharacteristic = 0x00001000
+	IOCAP_IMMUTABLE             DeviceCharacteristic = 0x00002000
+	IOCAP_BATCH_ATOMIC          DeviceCharacteristic = 0x00004000
+)
+
+// https://www.sqlite.org/c3ref/c_fcntl_begin_atomic_write.html
+type _FcntlOpcode uint32
+
+const (
+	_FCNTL_LOCKSTATE             _FcntlOpcode = 1
+	_FCNTL_GET_LOCKPROXYFILE     _FcntlOpcode = 2
+	_FCNTL_SET_LOCKPROXYFILE     _FcntlOpcode = 3
+	_FCNTL_LAST_ERRNO            _FcntlOpcode = 4
+	_FCNTL_SIZE_HINT             _FcntlOpcode = 5
+	_FCNTL_CHUNK_SIZE            _FcntlOpcode = 6
+	_FCNTL_FILE_POINTER          _FcntlOpcode = 7
+	_FCNTL_SYNC_OMITTED          _FcntlOpcode = 8
+	_FCNTL_WIN32_AV_RETRY        _FcntlOpcode = 9
+	_FCNTL_PERSIST_WAL           _FcntlOpcode = 10
+	_FCNTL_OVERWRITE             _FcntlOpcode = 11
+	_FCNTL_VFSNAME               _FcntlOpcode = 12
+	_FCNTL_POWERSAFE_OVERWRITE   _FcntlOpcode = 13
+	_FCNTL_PRAGMA                _FcntlOpcode = 14
+	_FCNTL_BUSYHANDLER           _FcntlOpcode = 15
+	_FCNTL_TEMPFILENAME          _FcntlOpcode = 16
+	_FCNTL_MMAP_SIZE             _FcntlOpcode = 18
+	_FCNTL_TRACE                 _FcntlOpcode = 19
+	_FCNTL_HAS_MOVED             _FcntlOpcode = 20
+	_FCNTL_SYNC                  _FcntlOpcode = 21
+	_FCNTL_COMMIT_PHASETWO       _FcntlOpcode = 22
+	_FCNTL_WIN32_SET_HANDLE      _FcntlOpcode = 23
+	_FCNTL_WAL_BLOCK             _FcntlOpcode = 24
+	_FCNTL_ZIPVFS                _FcntlOpcode = 25
+	_FCNTL_RBU                   _FcntlOpcode = 26
+	_FCNTL_VFS_POINTER           _FcntlOpcode = 27
+	_FCNTL_JOURNAL_POINTER       _FcntlOpcode = 28
+	_FCNTL_WIN32_GET_HANDLE      _FcntlOpcode = 29
+	_FCNTL_PDB                   _FcntlOpcode = 30
+	_FCNTL_BEGIN_ATOMIC_WRITE    _FcntlOpcode = 31
+	_FCNTL_COMMIT_ATOMIC_WRITE   _FcntlOpcode = 32
+	_FCNTL_ROLLBACK_ATOMIC_WRITE _FcntlOpcode = 33
+	_FCNTL_LOCK_TIMEOUT          _FcntlOpcode = 34
+	_FCNTL_DATA_VERSION          _FcntlOpcode = 35
+	_FCNTL_SIZE_LIMIT            _FcntlOpcode = 36
+	_FCNTL_CKPT_DONE             _FcntlOpcode = 37
+	_FCNTL_RESERVE_BYTES         _FcntlOpcode = 38
+	_FCNTL_CKPT_START            _FcntlOpcode = 39
+	_FCNTL_EXTERNAL_READER       _FcntlOpcode = 40
+	_FCNTL_CKSM_FILE             _FcntlOpcode = 41
+	_FCNTL_RESET_CACHE           _FcntlOpcode = 42
+)

vfs/file.go

@@ -0,0 +1,201 @@
+package vfs
+
+import (
+	"errors"
+	"io"
+	"io/fs"
+	"net/url"
+	"os"
+	"path/filepath"
+	"runtime"
+	"syscall"
+	"time"
+)
+
+type vfsOS struct{}
+
+func (vfsOS) FullPathname(path string) (string, error) {
+	path, err := filepath.Abs(path)
+	if err != nil {
+		return "", err
+	}
+	fi, err := os.Lstat(path)
+	if err != nil {
+		if errors.Is(err, fs.ErrNotExist) {
+			return path, nil
+		}
+		return "", err
+	}
+	if fi.Mode()&fs.ModeSymlink != 0 {
+		err = _OK_SYMLINK
+	}
+	return path, err
+}
+
+func (vfsOS) Delete(path string, syncDir bool) error {
+	err := os.Remove(path)
+	if err != nil {
+		if errors.Is(err, fs.ErrNotExist) {
+			return _IOERR_DELETE_NOENT
+		}
+		return err
+	}
+	if runtime.GOOS != "windows" && syncDir {
+		f, err := os.Open(filepath.Dir(path))
+		if err != nil {
+			return _OK
+		}
+		defer f.Close()
+		err = osSync(f, false, false)
+		if err != nil {
+			return _IOERR_DIR_FSYNC
+		}
+	}
+	return nil
+}
+
+func (vfsOS) Access(name string, flags AccessFlag) (bool, error) {
+	err := osAccess(name, flags)
+	if flags == ACCESS_EXISTS {
+		if errors.Is(err, fs.ErrNotExist) {
+			return false, nil
+		}
+	} else {
+		if errors.Is(err, fs.ErrPermission) {
+			return false, nil
+		}
+	}
+	return err == nil, err
+}
+
+func (vfsOS) Open(name string, flags OpenFlag) (File, OpenFlag, error) {
+	return vfsOS{}.OpenParams(name, flags, nil)
+}
+
+func (vfsOS) OpenParams(name string, flags OpenFlag, params url.Values) (File, OpenFlag, error) {
+	var oflags int
+	if flags&OPEN_EXCLUSIVE != 0 {
+		oflags |= os.O_EXCL
+	}
+	if flags&OPEN_CREATE != 0 {
+		oflags |= os.O_CREATE
+	}
+	if flags&OPEN_READONLY != 0 {
+		oflags |= os.O_RDONLY
+	}
+	if flags&OPEN_READWRITE != 0 {
+		oflags |= os.O_RDWR
+	}
+
+	var err error
+	var f *os.File
+	if name == "" {
+		f, err = os.CreateTemp("", "*.db")
+	} else {
+		f, err = osOpenFile(name, oflags, 0666)
+	}
+	if err != nil {
+		if errors.Is(err, syscall.EISDIR) {
+			return nil, flags, _CANTOPEN_ISDIR
+		}
+		return nil, flags, err
+	}
+
+	if modeof := params.Get("modeof"); modeof != "" {
+		if err = osSetMode(f, modeof); err != nil {
+			f.Close()
+			return nil, flags, _IOERR_FSTAT
+		}
+	}
+	if flags&OPEN_DELETEONCLOSE != 0 {
+		os.Remove(f.Name())
+	}
+
+	file := vfsFile{
+		File:     f,
+		psow:     true,
+		readOnly: flags&OPEN_READONLY != 0,
+		syncDir: runtime.GOOS != "windows" &&
+			flags&(OPEN_CREATE) != 0 &&
+			flags&(OPEN_MAIN_JOURNAL|OPEN_SUPER_JOURNAL|OPEN_WAL) != 0,
+	}
+	return &file, flags, nil
+}
+
+type vfsFile struct {
+	*os.File
+	lockTimeout time.Duration
+	lock        LockLevel
+	psow        bool
+	syncDir     bool
+	readOnly    bool
+}
+
+var (
+	// Ensure these interfaces are implemented:
+	_ FileLockState          = &vfsFile{}
+	_ FileHasMoved           = &vfsFile{}
+	_ FileSizeHint           = &vfsFile{}
+	_ FilePowersafeOverwrite = &vfsFile{}
+)
+
+func (f *vfsFile) Sync(flags SyncFlag) error {
+	dataonly := (flags & SYNC_DATAONLY) != 0
+	fullsync := (flags & 0x0f) == SYNC_FULL
+
+	err := osSync(f.File, fullsync, dataonly)
+	if err != nil {
+		return err
+	}
+	if runtime.GOOS != "windows" && f.syncDir {
+		f.syncDir = false
+		d, err := os.Open(filepath.Dir(f.File.Name()))
+		if err != nil {
+			return nil
+		}
+		defer d.Close()
+		err = osSync(d, false, false)
+		if err != nil {
+			return _IOERR_DIR_FSYNC
+		}
+	}
+	return nil
+}
+
+func (f *vfsFile) Size() (int64, error) {
+	return f.Seek(0, io.SeekEnd)
+}
+
+func (*vfsFile) SectorSize() int {
+	return _DEFAULT_SECTOR_SIZE
+}
+
+func (f *vfsFile) DeviceCharacteristics() DeviceCharacteristic {
+	if f.psow {
+		return IOCAP_POWERSAFE_OVERWRITE
+	}
+	return 0
+}
+
+func (f *vfsFile) SizeHint(size int64) error {
+	return osAllocate(f.File, size)
+}
+
+func (f *vfsFile) HasMoved() (bool, error) {
+	fi, err := f.Stat()
+	if err != nil {
+		return false, err
+	}
+	pi, err := os.Stat(f.Name())
+	if err != nil {
+		if errors.Is(err, fs.ErrNotExist) {
+			return true, nil
+		}
+		return false, err
+	}
+	return !os.SameFile(fi, pi), nil
+}
+
+func (f *vfsFile) LockState() LockLevel            { return f.lock }
+func (f *vfsFile) PowersafeOverwrite() bool        { return f.psow }
+func (f *vfsFile) SetPowersafeOverwrite(psow bool) { f.psow = psow }

vfs/lock.go

@@ -0,0 +1,150 @@
+package vfs
+
+import (
+	"os"
+	"time"
+
+	"github.com/ncruces/go-sqlite3/internal/util"
+)
+
+const (
+	_PENDING_BYTE  = 0x40000000
+	_RESERVED_BYTE = (_PENDING_BYTE + 1)
+	_SHARED_FIRST  = (_PENDING_BYTE + 2)
+	_SHARED_SIZE   = 510
+)
+
+func (f *vfsFile) Lock(lock LockLevel) error {
+	// Argument check. SQLite never explicitly requests a pending lock.
+	if lock != LOCK_SHARED && lock != LOCK_RESERVED && lock != LOCK_EXCLUSIVE {
+		panic(util.AssertErr())
+	}
+
+	switch {
+	case f.lock < LOCK_NONE || f.lock > LOCK_EXCLUSIVE:
+		// Connection state check.
+		panic(util.AssertErr())
+	case f.lock == LOCK_NONE && lock > LOCK_SHARED:
+		// We never move from unlocked to anything higher than a shared lock.
+		panic(util.AssertErr())
+	case f.lock != LOCK_SHARED && lock == LOCK_RESERVED:
+		// A shared lock is always held when a reserved lock is requested.
+		panic(util.AssertErr())
+	}
+
+	// If we already have an equal or more restrictive lock, do nothing.
+	if f.lock >= lock {
+		return nil
+	}
+
+	// Do not allow any kind of write-lock on a read-only database.
+	if f.readOnly && lock >= LOCK_RESERVED {
+		return _IOERR_LOCK
+	}
+
+	switch lock {
+	case LOCK_SHARED:
+		// Must be unlocked to get SHARED.
+		if f.lock != LOCK_NONE {
+			panic(util.AssertErr())
+		}
+		if rc := osGetSharedLock(f.File, f.lockTimeout); rc != _OK {
+			return rc
+		}
+		f.lock = LOCK_SHARED
+		return nil
+
+	case LOCK_RESERVED:
+		// Must be SHARED to get RESERVED.
+		if f.lock != LOCK_SHARED {
+			panic(util.AssertErr())
+		}
+		if rc := osGetReservedLock(f.File, f.lockTimeout); rc != _OK {
+			return rc
+		}
+		f.lock = LOCK_RESERVED
+		return nil
+
+	case LOCK_EXCLUSIVE:
+		// Must be SHARED, RESERVED or PENDING to get EXCLUSIVE.
+		if f.lock <= LOCK_NONE || f.lock >= LOCK_EXCLUSIVE {
+			panic(util.AssertErr())
+		}
+		// A PENDING lock is needed before acquiring an EXCLUSIVE lock.
+		if f.lock < LOCK_PENDING {
+			if rc := osGetPendingLock(f.File); rc != _OK {
+				return rc
+			}
+			f.lock = LOCK_PENDING
+		}
+		if rc := osGetExclusiveLock(f.File, f.lockTimeout); rc != _OK {
+			return rc
+		}
+		f.lock = LOCK_EXCLUSIVE
+		return nil
+
+	default:
+		panic(util.AssertErr())
+	}
+}
+
+func (f *vfsFile) Unlock(lock LockLevel) error {
+	// Argument check.
+	if lock != LOCK_NONE && lock != LOCK_SHARED {
+		panic(util.AssertErr())
+	}
+
+	// Connection state check.
+	if f.lock < LOCK_NONE || f.lock > LOCK_EXCLUSIVE {
+		panic(util.AssertErr())
+	}
+
+	// If we don't have a more restrictive lock, do nothing.
+	if f.lock <= lock {
+		return nil
+	}
+
+	switch lock {
+	case LOCK_SHARED:
+		if rc := osDowngradeLock(f.File, f.lock); rc != _OK {
+			return rc
+		}
+		f.lock = LOCK_SHARED
+		return nil
+
+	case LOCK_NONE:
+		rc := osReleaseLock(f.File, f.lock)
+		f.lock = LOCK_NONE
+		return rc
+
+	default:
+		panic(util.AssertErr())
+	}
+}
+
+func (f *vfsFile) CheckReservedLock() (bool, error) {
+	// Connection state check.
+	if f.lock < LOCK_NONE || f.lock > LOCK_EXCLUSIVE {
+		panic(util.AssertErr())
+	}
+
+	if f.lock >= LOCK_RESERVED {
+		return true, nil
+	}
+	return osCheckReservedLock(f.File)
+}
+
+func osGetReservedLock(file *os.File, timeout time.Duration) _ErrorCode {
+	// Acquire the RESERVED lock.
+	return osWriteLock(file, _RESERVED_BYTE, 1, timeout)
+}
+
+func osGetPendingLock(file *os.File) _ErrorCode {
+	// Acquire the PENDING lock.
+	return osWriteLock(file, _PENDING_BYTE, 1, 0)
+}
+
+func osCheckReservedLock(file *os.File) (bool, _ErrorCode) {
+	// Test the RESERVED lock.
+	return osCheckLock(file, _RESERVED_BYTE, 1)
+}

vfs/lock_test.go

@@ -0,0 +1,220 @@
+package vfs
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"runtime"
+	"testing"
+
+	"github.com/ncruces/go-sqlite3/internal/util"
+	"github.com/tetratelabs/wazero/experimental/wazerotest"
+)
+
+func Test_vfsLock(t *testing.T) {
+	switch runtime.GOOS {
+	case "linux", "darwin", "windows":
+		break
+	default:
+		t.Skip("OS lacks OFD locks")
+	}
+
+	name := filepath.Join(t.TempDir(), "test.db")
+
+	// Create a temporary file.
+	file1, err := os.OpenFile(name, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0666)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer file1.Close()
+
+	// Open the temporary file again.
+	file2, err := os.OpenFile(name, os.O_RDWR, 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer file2.Close()
+
+	const (
+		pFile1  = 4
+		pFile2  = 16
+		pOutput = 32
+	)
+	mod := wazerotest.NewModule(wazerotest.NewMemory(wazerotest.PageSize))
+	ctx, vfs := NewContext(context.TODO())
+	defer vfs.Close()
+
+	vfsFileRegister(ctx, mod, pFile1, &vfsFile{File: file1})
+	vfsFileRegister(ctx, mod, pFile2, &vfsFile{File: file2})
+
+	rc := vfsCheckReservedLock(ctx, mod, pFile1, pOutput)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+	if got := util.ReadUint32(mod, pOutput); got != 0 {
+		t.Error("file was locked")
+	}
+	rc = vfsCheckReservedLock(ctx, mod, pFile2, pOutput)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+	if got := util.ReadUint32(mod, pOutput); got != 0 {
+		t.Error("file was locked")
+	}
+	rc = vfsFileControl(ctx, mod, pFile2, _FCNTL_LOCKSTATE, pOutput)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+	if got := util.ReadUint32(mod, pOutput); got != uint32(LOCK_NONE) {
+		t.Error("invalid lock state", got)
+	}
+
+	rc = vfsLock(ctx, mod, pFile2, LOCK_SHARED)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+
+	rc = vfsCheckReservedLock(ctx, mod, pFile1, pOutput)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+	if got := util.ReadUint32(mod, pOutput); got != 0 {
+		t.Error("file was locked")
+	}
+	rc = vfsCheckReservedLock(ctx, mod, pFile2, pOutput)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+	if got := util.ReadUint32(mod, pOutput); got != 0 {
+		t.Error("file was locked")
+	}
+	rc = vfsFileControl(ctx, mod, pFile2, _FCNTL_LOCKSTATE, pOutput)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+	if got := util.ReadUint32(mod, pOutput); got != uint32(LOCK_SHARED) {
+		t.Error("invalid lock state", got)
+	}
+
+	rc = vfsLock(ctx, mod, pFile2, LOCK_RESERVED)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+	rc = vfsLock(ctx, mod, pFile2, LOCK_SHARED)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+
+	rc = vfsCheckReservedLock(ctx, mod, pFile1, pOutput)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+	if got := util.ReadUint32(mod, pOutput); got == 0 {
+		t.Error("file wasn't locked")
+	}
+	rc = vfsCheckReservedLock(ctx, mod, pFile2, pOutput)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+	if got := util.ReadUint32(mod, pOutput); got == 0 {
+		t.Error("file wasn't locked")
+	}
+	rc = vfsFileControl(ctx, mod, pFile2, _FCNTL_LOCKSTATE, pOutput)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+	if got := util.ReadUint32(mod, pOutput); got != uint32(LOCK_RESERVED) {
+		t.Error("invalid lock state", got)
+	}
+
+	rc = vfsLock(ctx, mod, pFile2, LOCK_EXCLUSIVE)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+
+	rc = vfsCheckReservedLock(ctx, mod, pFile1, pOutput)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+	if got := util.ReadUint32(mod, pOutput); got == 0 {
+		t.Error("file wasn't locked")
+	}
+	rc = vfsCheckReservedLock(ctx, mod, pFile2, pOutput)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+	if got := util.ReadUint32(mod, pOutput); got == 0 {
+		t.Error("file wasn't locked")
+	}
+	rc = vfsFileControl(ctx, mod, pFile2, _FCNTL_LOCKSTATE, pOutput)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+	if got := util.ReadUint32(mod, pOutput); got != uint32(LOCK_EXCLUSIVE) {
+		t.Error("invalid lock state", got)
+	}
+
+	rc = vfsLock(ctx, mod, pFile1, LOCK_SHARED)
+	if rc == _OK {
+		t.Fatal("returned", rc)
+	}
+
+	rc = vfsCheckReservedLock(ctx, mod, pFile1, pOutput)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+	if got := util.ReadUint32(mod, pOutput); got == 0 {
+		t.Error("file wasn't locked")
+	}
+	rc = vfsCheckReservedLock(ctx, mod, pFile2, pOutput)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+	if got := util.ReadUint32(mod, pOutput); got == 0 {
+		t.Error("file wasn't locked")
+	}
+	rc = vfsFileControl(ctx, mod, pFile1, _FCNTL_LOCKSTATE, pOutput)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+	if got := util.ReadUint32(mod, pOutput); got != uint32(LOCK_NONE) {
+		t.Error("invalid lock state", got)
+	}
+
+	rc = vfsUnlock(ctx, mod, pFile2, LOCK_SHARED)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+
+	rc = vfsCheckReservedLock(ctx, mod, pFile1, pOutput)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+	if got := util.ReadUint32(mod, pOutput); got != 0 {
+		t.Error("file was locked")
+	}
+	rc = vfsCheckReservedLock(ctx, mod, pFile2, pOutput)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+	if got := util.ReadUint32(mod, pOutput); got != 0 {
+		t.Error("file was locked")
+	}
+
+	rc = vfsLock(ctx, mod, pFile1, LOCK_SHARED)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+	rc = vfsFileControl(ctx, mod, pFile1, _FCNTL_LOCKSTATE, pOutput)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+	if got := util.ReadUint32(mod, pOutput); got != uint32(LOCK_SHARED) {
+		t.Error("invalid lock state", got)
+	}
+
+	rc = vfsFileControl(ctx, mod, pFile1, _FCNTL_LOCK_TIMEOUT, 1)
+	if rc != _OK {
+		t.Fatal("returned", rc)
+	}
+}

vfs/memdb/README.md

@@ -0,0 +1,9 @@
+# Go `"memdb"` SQLite VFS
+
+This package implements the [`"memdb"`](https://www.sqlite.org/src/file/src/memdb.c)
+SQLite VFS in pure Go.
+
+It has some benefits over the C version:
+- the memory backing the database needs not be contiguous,
+- the database can grow/shrink incrementally without copying,
+- reader-writer concurrency is slightly improved.

vfs/memdb/api.go

@@ -0,0 +1,59 @@
+// Package memdb implements the "memdb" SQLite VFS.
+//
+// The "memdb" [vfs.VFS] allows the same in-memory database to be shared
+// among multiple database connections in the same process,
+// as long as the database name begins with "/".
+//
+// Importing package memdb registers the VFS.
+//
+//	import _ "github.com/ncruces/go-sqlite3/vfs/memdb"
+package memdb
+
+import (
+	"sync"
+
+	"github.com/ncruces/go-sqlite3/vfs"
+)
+
+func init() {
+	vfs.Register("memdb", memVFS{})
+}
+
+var (
+	memoryMtx sync.Mutex
+	// +checklocks:memoryMtx
+	memoryDBs = map[string]*memDB{}
+)
+
+// Create creates a shared memory database,
+// using data as its initial contents.
+// The new database takes ownership of data,
+// and the caller should not use data after this call.
+func Create(name string, data []byte) {
+	memoryMtx.Lock()
+	defer memoryMtx.Unlock()
+
+	db := new(memDB)
+	db.size = int64(len(data))
+
+	sectors := divRoundUp(db.size, sectorSize)
+	db.data = make([]*[sectorSize]byte, sectors)
+	for i := range db.data {
+		sector := data[i*sectorSize:]
+		if len(sector) >= sectorSize {
+			db.data[i] = (*[sectorSize]byte)(sector)
+		} else {
+			db.data[i] = new([sectorSize]byte)
+			copy((*db.data[i])[:], sector)
+		}
+	}
+
+	memoryDBs[name] = db
+}
+
+// Delete deletes a shared memory database.
+func Delete(name string) {
+	memoryMtx.Lock()
+	defer memoryMtx.Unlock()
+	delete(memoryDBs, name)
+}

vfs/memdb/example_test.go

@@ -0,0 +1,51 @@
+package memdb_test
+
+import (
+	"database/sql"
+	"fmt"
+	"log"
+
+	_ "embed"
+
+	_ "github.com/ncruces/go-sqlite3/driver"
+	_ "github.com/ncruces/go-sqlite3/embed"
+	"github.com/ncruces/go-sqlite3/vfs/memdb"
+)
+
+//go:embed testdata/test.db
+var testDB []byte
+
+func Example() {
+	memdb.Create("test.db", testDB)
+
+	db, err := sql.Open("sqlite3", "file:/test.db?vfs=memdb")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer db.Close()
+
+	_, err = db.Exec(`INSERT INTO users (id, name) VALUES (3, 'rust')`)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	rows, err := db.Query(`SELECT id, name FROM users`)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer rows.Close()
+
+	for rows.Next() {
+		var id, name string
+		err = rows.Scan(&id, &name)
+		if err != nil {
+			log.Fatal(err)
+		}
+		fmt.Printf("%s %s\n", id, name)
+	}
+	// Output:
+	// 0 go
+	// 1 zig
+	// 2 whatever
+	// 3 rust
+}

vfs/memdb/memdb.go

@@ -0,0 +1,294 @@
+package memdb
+
+import (
+	"io"
+	"runtime"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/ncruces/go-sqlite3"
+	"github.com/ncruces/go-sqlite3/vfs"
+)
+
+type memVFS struct{}
+
+func (memVFS) Open(name string, flags vfs.OpenFlag) (vfs.File, vfs.OpenFlag, error) {
+	// Allowed file types:
+	// - databases, which only do page aligned reads/writes;
+	// - temp journals, used by the sorter, which does the same.
+	const types = vfs.OPEN_MAIN_DB |
+		vfs.OPEN_TRANSIENT_DB |
+		vfs.OPEN_TEMP_DB |
+		vfs.OPEN_TEMP_JOURNAL
+	if flags&types == 0 {
+		return nil, flags, sqlite3.CANTOPEN
+	}
+
+	var db *memDB
+
+	shared := strings.HasPrefix(name, "/")
+	if shared {
+		memoryMtx.Lock()
+		defer memoryMtx.Unlock()
+		db = memoryDBs[name[1:]]
+	}
+	if db == nil {
+		if flags&vfs.OPEN_CREATE == 0 {
+			return nil, flags, sqlite3.CANTOPEN
+		}
+		db = new(memDB)
+	}
+	if shared {
+		memoryDBs[name[1:]] = db // +checklocksignore: lock is held
+	}
+
+	return &memFile{
+		memDB:    db,
+		readOnly: flags&vfs.OPEN_READONLY != 0,
+	}, flags | vfs.OPEN_MEMORY, nil
+}
+
+func (memVFS) Delete(name string, dirSync bool) error {
+	return sqlite3.IOERR_DELETE
+}
+
+func (memVFS) Access(name string, flag vfs.AccessFlag) (bool, error) {
+	return false, nil
+}
+
+func (memVFS) FullPathname(name string) (string, error) {
+	return name, nil
+}
+
+// Must be a multiple of 64K (the largest page size).
+const sectorSize = 65536
+
+type memDB struct {
+	// +checklocks:lockMtx
+	pending *memFile
+	// +checklocks:lockMtx
+	reserved *memFile
+
+	// +checklocks:dataMtx
+	data []*[sectorSize]byte
+
+	// +checklocks:dataMtx
+	size int64
+
+	// +checklocks:lockMtx
+	shared int
+
+	lockMtx sync.Mutex
+	dataMtx sync.RWMutex
+}
+
+type memFile struct {
+	*memDB
+	lock     vfs.LockLevel
+	readOnly bool
+}
+
+var (
+	// Ensure these interfaces are implemented:
+	_ vfs.FileLockState = &memFile{}
+	_ vfs.FileSizeHint  = &memFile{}
+)
+
+func (m *memFile) Close() error {
+	return m.Unlock(vfs.LOCK_NONE)
+}
+
+func (m *memFile) ReadAt(b []byte, off int64) (n int, err error) {
+	m.dataMtx.RLock()
+	defer m.dataMtx.RUnlock()
+
+	if off >= m.size {
+		return 0, io.EOF
+	}
+
+	base := off / sectorSize
+	rest := off % sectorSize
+	have := int64(sectorSize)
+	if base == int64(len(m.data))-1 {
+		have = modRoundUp(m.size, sectorSize)
+	}
+	n = copy(b, (*m.data[base])[rest:have])
+	if n < len(b) {
+		// Assume reads are page aligned.
+		return 0, io.ErrNoProgress
+	}
+	return n, nil
+}
+
+func (m *memFile) WriteAt(b []byte, off int64) (n int, err error) {
+	m.dataMtx.Lock()
+	defer m.dataMtx.Unlock()
+
+	base := off / sectorSize
+	rest := off % sectorSize
+	for base >= int64(len(m.data)) {
+		m.data = append(m.data, new([sectorSize]byte))
+	}
+	n = copy((*m.data[base])[rest:], b)
+	if n < len(b) {
+		// Assume writes are page aligned.
+		return 0, io.ErrShortWrite
+	}
+	if size := off + int64(len(b)); size > m.size {
+		m.size = size
+	}
+	return n, nil
+}
+
+func (m *memFile) Truncate(size int64) error {
+	m.dataMtx.Lock()
+	defer m.dataMtx.Unlock()
+	return m.truncate(size)
+}
+
+// +checklocks:m.dataMtx
+func (m *memFile) truncate(size int64) error {
+	if size < m.size {
+		base := size / sectorSize
+		rest := size % sectorSize
+		if rest != 0 {
+			clear((*m.data[base])[rest:])
+		}
+	}
+	sectors := divRoundUp(size, sectorSize)
+	for sectors > int64(len(m.data)) {
+		m.data = append(m.data, new([sectorSize]byte))
+	}
+	clear(m.data[sectors:])
+	m.data = m.data[:sectors]
+	m.size = size
+	return nil
+}
+
+func (*memFile) Sync(flag vfs.SyncFlag) error {
+	return nil
+}
+
+func (m *memFile) Size() (int64, error) {
+	m.dataMtx.RLock()
+	defer m.dataMtx.RUnlock()
+	return m.size, nil
+}
+
+func (m *memFile) Lock(lock vfs.LockLevel) error {
+	if m.lock >= lock {
+		return nil
+	}
+
+	if m.readOnly && lock >= vfs.LOCK_RESERVED {
+		return sqlite3.IOERR_LOCK
+	}
+
+	m.lockMtx.Lock()
+	defer m.lockMtx.Unlock()
+
+	switch lock {
+	case vfs.LOCK_SHARED:
+		if m.pending != nil {
+			return sqlite3.BUSY
+		}
+		m.shared++
+
+	case vfs.LOCK_RESERVED:
+		if m.reserved != nil {
+			return sqlite3.BUSY
+		}
+		m.reserved = m
+
+	case vfs.LOCK_EXCLUSIVE:
+		if m.lock < vfs.LOCK_PENDING {
+			if m.pending != nil {
+				return sqlite3.BUSY
+			}
+			m.lock = vfs.LOCK_PENDING
+			m.pending = m
+		}
+
+		for start := time.Now(); m.shared > 1; {
+			if time.Since(start) > time.Millisecond {
+				return sqlite3.BUSY
+			}
+			m.lockMtx.Unlock()
+			runtime.Gosched()
+			m.lockMtx.Lock()
+		}
+	}
+
+	m.lock = lock
+	return nil
+}
+
+func (m *memFile) Unlock(lock vfs.LockLevel) error {
+	if m.lock <= lock {
+		return nil
+	}
+
+	m.lockMtx.Lock()
+	defer m.lockMtx.Unlock()
+
+	if m.pending == m {
+		m.pending = nil
+	}
+	if m.reserved == m {
+		m.reserved = nil
+	}
+	if lock < vfs.LOCK_SHARED {
+		m.shared--
+	}
+	m.lock = lock
+	return nil
+}
+
+func (m *memFile) CheckReservedLock() (bool, error) {
+	if m.lock >= vfs.LOCK_RESERVED {
+		return true, nil
+	}
+	m.lockMtx.Lock()
+	defer m.lockMtx.Unlock()
+	return m.reserved != nil, nil
+}
+
+func (*memFile) SectorSize() int {
+	return sectorSize
+}
+
+func (*memFile) DeviceCharacteristics() vfs.DeviceCharacteristic {
+	return vfs.IOCAP_ATOMIC |
+		vfs.IOCAP_SEQUENTIAL |
+		vfs.IOCAP_SAFE_APPEND |
+		vfs.IOCAP_POWERSAFE_OVERWRITE
+}
+
+func (m *memFile) SizeHint(size int64) error {
+	m.dataMtx.Lock()
+	defer m.dataMtx.Unlock()
+	if size > m.size {
+		return m.truncate(size)
+	}
+	return nil
+}
+
+func (m *memFile) LockState() vfs.LockLevel {
+	return m.lock
+}
+
+func divRoundUp(a, b int64) int64 {
+	return (a + b - 1) / b
+}
+
+func modRoundUp(a, b int64) int64 {
+	return b - (b-a%b)%b
+}
+
+func clear[T any](b []T) {
+	var zero T
+	for i := range b {
+		b[i] = zero
+	}
+}

vfs/os_bsd.go

@@ -0,0 +1,56 @@
+//go:build freebsd || openbsd || netbsd || dragonfly || (darwin && sqlite3_bsd)
+
+package vfs
+
+import (
+	"os"
+	"time"
+
+	"golang.org/x/sys/unix"
+)
+
+func osUnlock(file *os.File, start, len int64) _ErrorCode {
+	if start == 0 && len == 0 {
+		err := unix.Flock(int(file.Fd()), unix.LOCK_UN)
+		if err != nil {
+			return _IOERR_UNLOCK
+		}
+	}
+	return _OK
+}
+
+func osLock(file *os.File, how int, timeout time.Duration, def _ErrorCode) _ErrorCode {
+	var err error
+	for {
+		err = unix.Flock(int(file.Fd()), how)
+		if errno, _ := err.(unix.Errno); errno != unix.EAGAIN {
+			break
+		}
+		if timeout < time.Millisecond {
+			break
+		}
+		timeout -= time.Millisecond
+		time.Sleep(time.Millisecond)
+	}
+	return osLockErrorCode(err, def)
+}
+
+func osReadLock(file *os.File, start, len int64, timeout time.Duration) _ErrorCode {
+	return osLock(file, unix.LOCK_SH|unix.LOCK_NB, timeout, _IOERR_RDLOCK)
+}
+
+func osWriteLock(file *os.File, start, len int64, timeout time.Duration) _ErrorCode {
+	return osLock(file, unix.LOCK_EX|unix.LOCK_NB, timeout, _IOERR_LOCK)
+}
+
+func osCheckLock(file *os.File, start, len int64) (bool, _ErrorCode) {
+	lock := unix.Flock_t{
+		Type:  unix.F_RDLCK,
+		Start: start,
+		Len:   len,
+	}
+	if unix.FcntlFlock(file.Fd(), unix.F_GETLK, &lock) != nil {
+		return false, _IOERR_CHECKRESERVEDLOCK
+	}
+	return lock.Type != unix.F_UNLCK, _OK
+}

vfs/os_darwin.go

@@ -0,0 +1,106 @@
+//go:build !sqlite3_bsd
+
+package vfs
+
+import (
+	"io"
+	"os"
+	"time"
+
+	"golang.org/x/sys/unix"
+)
+
+const (
+	// https://github.com/apple/darwin-xnu/blob/main/bsd/sys/fcntl.h
+	_F_OFD_SETLK         = 90
+	_F_OFD_SETLKW        = 91
+	_F_OFD_GETLK         = 92
+	_F_OFD_SETLKWTIMEOUT = 93
+)
+
+type flocktimeout_t struct {
+	fl      unix.Flock_t
+	timeout unix.Timespec
+}
+
+func osSync(file *os.File, fullsync, dataonly bool) error {
+	if fullsync {
+		return file.Sync()
+	}
+	return unix.Fsync(int(file.Fd()))
+}
+
+func osAllocate(file *os.File, size int64) error {
+	off, err := file.Seek(0, io.SeekEnd)
+	if err != nil {
+		return err
+	}
+	if size <= off {
+		return nil
+	}
+
+	// https://stackoverflow.com/a/11497568/867786
+	store := unix.Fstore_t{
+		Flags:   unix.F_ALLOCATECONTIG,
+		Posmode: unix.F_PEOFPOSMODE,
+		Offset:  0,
+		Length:  size,
+	}
+
+	// Try to get a continuous chunk of disk space.
+	err = unix.FcntlFstore(file.Fd(), unix.F_PREALLOCATE, &store)
+	if err != nil {
+		// OK, perhaps we are too fragmented, allocate non-continuous.
+		store.Flags = unix.F_ALLOCATEALL
+		unix.FcntlFstore(file.Fd(), unix.F_PREALLOCATE, &store)
+	}
+	return file.Truncate(size)
+}
+
+func osUnlock(file *os.File, start, len int64) _ErrorCode {
+	err := unix.FcntlFlock(file.Fd(), _F_OFD_SETLK, &unix.Flock_t{
+		Type:  unix.F_UNLCK,
+		Start: start,
+		Len:   len,
+	})
+	if err != nil {
+		return _IOERR_UNLOCK
+	}
+	return _OK
+}
+
+func osLock(file *os.File, typ int16, start, len int64, timeout time.Duration, def _ErrorCode) _ErrorCode {
+	lock := flocktimeout_t{fl: unix.Flock_t{
+		Type:  typ,
+		Start: start,
+		Len:   len,
+	}}
+	var err error
+	if timeout == 0 {
+		err = unix.FcntlFlock(file.Fd(), _F_OFD_SETLK, &lock.fl)
+	} else {
+		lock.timeout = unix.NsecToTimespec(int64(timeout / time.Nanosecond))
+		err = unix.FcntlFlock(file.Fd(), _F_OFD_SETLKWTIMEOUT, &lock.fl)
+	}
+	return osLockErrorCode(err, def)
+}
+
+func osReadLock(file *os.File, start, len int64, timeout time.Duration) _ErrorCode {
+	return osLock(file, unix.F_RDLCK, start, len, timeout, _IOERR_RDLOCK)
+}
+
+func osWriteLock(file *os.File, start, len int64, timeout time.Duration) _ErrorCode {
+	return osLock(file, unix.F_WRLCK, start, len, timeout, _IOERR_LOCK)
+}
+
+func osCheckLock(file *os.File, start, len int64) (bool, _ErrorCode) {
+	lock := unix.Flock_t{
+		Type:  unix.F_RDLCK,
+		Start: start,
+		Len:   len,
+	}
+	if unix.FcntlFlock(file.Fd(), _F_OFD_GETLK, &lock) != nil {
+		return false, _IOERR_CHECKRESERVEDLOCK
+	}
+	return lock.Type != unix.F_UNLCK, _OK
+}

vfs/os_linux.go

@@ -0,0 +1,25 @@
+package vfs
+
+import (
+	"os"
+
+	"golang.org/x/sys/unix"
+)
+
+func osSync(file *os.File, fullsync, dataonly bool) error {
+	if dataonly {
+		_, _, err := unix.Syscall(unix.SYS_FDATASYNC, file.Fd(), 0, 0)
+		if err != 0 {
+			return err
+		}
+		return nil
+	}
+	return file.Sync()
+}
+
+func osAllocate(file *os.File, size int64) error {
+	if size == 0 {
+		return nil
+	}
+	return unix.Fallocate(int(file.Fd()), 0, 0, size)
+}

vfs/os_ofd.go

@@ -0,0 +1,63 @@
+//go:build linux || illumos
+
+package vfs
+
+import (
+	"os"
+	"time"
+
+	"golang.org/x/sys/unix"
+)
+
+func osUnlock(file *os.File, start, len int64) _ErrorCode {
+	err := unix.FcntlFlock(file.Fd(), unix.F_OFD_SETLK, &unix.Flock_t{
+		Type:  unix.F_UNLCK,
+		Start: start,
+		Len:   len,
+	})
+	if err != nil {
+		return _IOERR_UNLOCK
+	}
+	return _OK
+}
+
+func osLock(file *os.File, typ int16, start, len int64, timeout time.Duration, def _ErrorCode) _ErrorCode {
+	lock := unix.Flock_t{
+		Type:  typ,
+		Start: start,
+		Len:   len,
+	}
+	var err error
+	for {
+		err = unix.FcntlFlock(file.Fd(), unix.F_OFD_SETLK, &lock)
+		if errno, _ := err.(unix.Errno); errno != unix.EAGAIN {
+			break
+		}
+		if timeout < time.Millisecond {
+			break
+		}
+		timeout -= time.Millisecond
+		time.Sleep(time.Millisecond)
+	}
+	return osLockErrorCode(err, def)
+}
+
+func osReadLock(file *os.File, start, len int64, timeout time.Duration) _ErrorCode {
+	return osLock(file, unix.F_RDLCK, start, len, timeout, _IOERR_RDLOCK)
+}
+
+func osWriteLock(file *os.File, start, len int64, timeout time.Duration) _ErrorCode {
+	return osLock(file, unix.F_WRLCK, start, len, timeout, _IOERR_LOCK)
+}
+
+func osCheckLock(file *os.File, start, len int64) (bool, _ErrorCode) {
+	lock := unix.Flock_t{
+		Type:  unix.F_RDLCK,
+		Start: start,
+		Len:   len,
+	}
+	if unix.FcntlFlock(file.Fd(), unix.F_OFD_GETLK, &lock) != nil {
+		return false, _IOERR_CHECKRESERVEDLOCK
+	}
+	return lock.Type != unix.F_UNLCK, _OK
+}

vfs/os_other.go

@@ -0,0 +1,23 @@
+//go:build !linux && (!darwin || sqlite3_bsd)
+
+package vfs
+
+import (
+	"io"
+	"os"
+)
+
+func osSync(file *os.File, fullsync, dataonly bool) error {
+	return file.Sync()
+}
+
+func osAllocate(file *os.File, size int64) error {
+	off, err := file.Seek(0, io.SeekEnd)
+	if err != nil {
+		return err
+	}
+	if size <= off {
+		return nil
+	}
+	return file.Truncate(size)
+}

vfs/os_unix.go

@@ -0,0 +1,100 @@
+//go:build unix
+
+package vfs
+
+import (
+	"io/fs"
+	"os"
+	"syscall"
+	"time"
+
+	"golang.org/x/sys/unix"
+)
+
+func osOpenFile(name string, flag int, perm fs.FileMode) (*os.File, error) {
+	return os.OpenFile(name, flag, perm)
+}
+
+func osAccess(path string, flags AccessFlag) error {
+	var access uint32 // unix.F_OK
+	switch flags {
+	case ACCESS_READWRITE:
+		access = unix.R_OK | unix.W_OK
+	case ACCESS_READ:
+		access = unix.R_OK
+	}
+	return unix.Access(path, access)
+}
+
+func osSetMode(file *os.File, modeof string) error {
+	fi, err := os.Stat(modeof)
+	if err != nil {
+		return err
+	}
+	file.Chmod(fi.Mode())
+	if sys, ok := fi.Sys().(*syscall.Stat_t); ok {
+		file.Chown(int(sys.Uid), int(sys.Gid))
+	}
+	return nil
+}
+
+func osGetSharedLock(file *os.File, timeout time.Duration) _ErrorCode {
+	// Test the PENDING lock before acquiring a new SHARED lock.
+	if pending, _ := osCheckLock(file, _PENDING_BYTE, 1); pending {
+		return _BUSY
+	}
+	// Acquire the SHARED lock.
+	return osReadLock(file, _SHARED_FIRST, _SHARED_SIZE, timeout)
+}
+
+func osGetExclusiveLock(file *os.File, timeout time.Duration) _ErrorCode {
+	if timeout == 0 {
+		timeout = time.Millisecond
+	}
+
+	// Acquire the EXCLUSIVE lock.
+	return osWriteLock(file, _SHARED_FIRST, _SHARED_SIZE, timeout)
+}
+
+func osDowngradeLock(file *os.File, state LockLevel) _ErrorCode {
+	if state >= LOCK_EXCLUSIVE {
+		// Downgrade to a SHARED lock.
+		if rc := osReadLock(file, _SHARED_FIRST, _SHARED_SIZE, 0); rc != _OK {
+			// In theory, the downgrade to a SHARED cannot fail because another
+			// process is holding an incompatible lock. If it does, this
+			// indicates that the other process is not following the locking
+			// protocol. If this happens, return _IOERR_RDLOCK. Returning
+			// BUSY would confuse the upper layer.
+			return _IOERR_RDLOCK
+		}
+	}
+	// Release the PENDING and RESERVED locks.
+	return osUnlock(file, _PENDING_BYTE, 2)
+}
+
+func osReleaseLock(file *os.File, _ LockLevel) _ErrorCode {
+	// Release all locks.
+	return osUnlock(file, 0, 0)
+}
+
+func osLockErrorCode(err error, def _ErrorCode) _ErrorCode {
+	if err == nil {
+		return _OK
+	}
+	if errno, ok := err.(unix.Errno); ok {
+		switch errno {
+		case
+			unix.EACCES,
+			unix.EAGAIN,
+			unix.EBUSY,
+			unix.EINTR,
+			unix.ENOLCK,
+			unix.EDEADLK,
+			unix.ETIMEDOUT:
+			return _BUSY
+		case unix.EPERM:
+			return _PERM
+		}
+	}
+	return def
+}

vfs/os_windows.go

@@ -0,0 +1,249 @@
+package vfs
+
+import (
+	"io/fs"
+	"os"
+	"syscall"
+	"time"
+
+	"golang.org/x/sys/windows"
+)
+
+// osOpenFile is a simplified copy of [os.openFileNolog]
+// that uses syscall.FILE_SHARE_DELETE.
+// https://go.dev/src/os/file_windows.go
+//
+// See: https://go.dev/issue/32088
+func osOpenFile(name string, flag int, perm fs.FileMode) (*os.File, error) {
+	if name == "" {
+		return nil, &os.PathError{Op: "open", Path: name, Err: syscall.ENOENT}
+	}
+	r, e := syscallOpen(name, flag, uint32(perm.Perm()))
+	if e != nil {
+		return nil, &os.PathError{Op: "open", Path: name, Err: e}
+	}
+	return os.NewFile(uintptr(r), name), nil
+}
+
+func osAccess(path string, flags AccessFlag) error {
+	fi, err := os.Stat(path)
+	if err != nil {
+		return err
+	}
+	if flags == ACCESS_EXISTS {
+		return nil
+	}
+
+	var want fs.FileMode = windows.S_IRUSR
+	if flags == ACCESS_READWRITE {
+		want |= windows.S_IWUSR
+	}
+	if fi.IsDir() {
+		want |= windows.S_IXUSR
+	}
+	if fi.Mode()&want != want {
+		return fs.ErrPermission
+	}
+	return nil
+}
+
+func osSetMode(file *os.File, modeof string) error {
+	fi, err := os.Stat(modeof)
+	if err != nil {
+		return err
+	}
+	file.Chmod(fi.Mode())
+	return nil
+}
+
+func osGetSharedLock(file *os.File, timeout time.Duration) _ErrorCode {
+	// Acquire the PENDING lock temporarily before acquiring a new SHARED lock.
+	rc := osReadLock(file, _PENDING_BYTE, 1, timeout)
+
+	if rc == _OK {
+		// Acquire the SHARED lock.
+		rc = osReadLock(file, _SHARED_FIRST, _SHARED_SIZE, 0)
+
+		// Release the PENDING lock.
+		osUnlock(file, _PENDING_BYTE, 1)
+	}
+	return rc
+}
+
+func osGetExclusiveLock(file *os.File, timeout time.Duration) _ErrorCode {
+	if timeout == 0 {
+		timeout = time.Millisecond
+	}
+
+	// Release the SHARED lock.
+	osUnlock(file, _SHARED_FIRST, _SHARED_SIZE)
+
+	// Acquire the EXCLUSIVE lock.
+	rc := osWriteLock(file, _SHARED_FIRST, _SHARED_SIZE, timeout)
+
+	if rc != _OK {
+		// Reacquire the SHARED lock.
+		osReadLock(file, _SHARED_FIRST, _SHARED_SIZE, 0)
+	}
+	return rc
+}
+
+func osDowngradeLock(file *os.File, state LockLevel) _ErrorCode {
+	if state >= LOCK_EXCLUSIVE {
+		// Release the SHARED lock.
+		osUnlock(file, _SHARED_FIRST, _SHARED_SIZE)
+
+		// Reacquire the SHARED lock.
+		if rc := osReadLock(file, _SHARED_FIRST, _SHARED_SIZE, 0); rc != _OK {
+			// This should never happen.
+			// We should always be able to reacquire the read lock.
+			return _IOERR_RDLOCK
+		}
+	}
+
+	// Release the PENDING and RESERVED locks.
+	if state >= LOCK_RESERVED {
+		osUnlock(file, _RESERVED_BYTE, 1)
+	}
+	if state >= LOCK_PENDING {
+		osUnlock(file, _PENDING_BYTE, 1)
+	}
+	return _OK
+}
+
+func osReleaseLock(file *os.File, state LockLevel) _ErrorCode {
+	// Release all locks.
+	if state >= LOCK_RESERVED {
+		osUnlock(file, _RESERVED_BYTE, 1)
+	}
+	if state >= LOCK_SHARED {
+		osUnlock(file, _SHARED_FIRST, _SHARED_SIZE)
+	}
+	if state >= LOCK_PENDING {
+		osUnlock(file, _PENDING_BYTE, 1)
+	}
+	return _OK
+}
+
+func osUnlock(file *os.File, start, len uint32) _ErrorCode {
+	err := windows.UnlockFileEx(windows.Handle(file.Fd()),
+		0, len, 0, &windows.Overlapped{Offset: start})
+	if err == windows.ERROR_NOT_LOCKED {
+		return _OK
+	}
+	if err != nil {
+		return _IOERR_UNLOCK
+	}
+	return _OK
+}
+
+func osLock(file *os.File, flags, start, len uint32, timeout time.Duration, def _ErrorCode) _ErrorCode {
+	var err error
+	for {
+		err = windows.LockFileEx(windows.Handle(file.Fd()), flags,
+			0, len, 0, &windows.Overlapped{Offset: start})
+		if errno, _ := err.(windows.Errno); errno != windows.ERROR_LOCK_VIOLATION {
+			break
+		}
+		if timeout < time.Millisecond {
+			break
+		}
+		timeout -= time.Millisecond
+		time.Sleep(time.Millisecond)
+	}
+	return osLockErrorCode(err, def)
+}
+
+func osReadLock(file *os.File, start, len uint32, timeout time.Duration) _ErrorCode {
+	return osLock(file,
+		windows.LOCKFILE_FAIL_IMMEDIATELY,
+		start, len, timeout, _IOERR_RDLOCK)
+}
+
+func osWriteLock(file *os.File, start, len uint32, timeout time.Duration) _ErrorCode {
+	return osLock(file,
+		windows.LOCKFILE_FAIL_IMMEDIATELY|windows.LOCKFILE_EXCLUSIVE_LOCK,
+		start, len, timeout, _IOERR_LOCK)
+}
+
+func osCheckLock(file *os.File, start, len uint32) (bool, _ErrorCode) {
+	rc := osLock(file,
+		windows.LOCKFILE_FAIL_IMMEDIATELY,
+		start, len, 0, _IOERR_CHECKRESERVEDLOCK)
+	if rc == _BUSY {
+		return true, _OK
+	}
+	if rc == _OK {
+		osUnlock(file, start, len)
+	}
+	return false, rc
+}
+
+func osLockErrorCode(err error, def _ErrorCode) _ErrorCode {
+	if err == nil {
+		return _OK
+	}
+	if errno, ok := err.(windows.Errno); ok {
+		// https://devblogs.microsoft.com/oldnewthing/20140905-00/?p=63
+		switch errno {
+		case
+			windows.ERROR_LOCK_VIOLATION,
+			windows.ERROR_IO_PENDING,
+			windows.ERROR_OPERATION_ABORTED:
+			return _BUSY
+		}
+	}
+	return def
+}
+
+// syscallOpen is a simplified copy of [syscall.Open]
+// that uses syscall.FILE_SHARE_DELETE.
+// https://go.dev/src/syscall/syscall_windows.go
+func syscallOpen(path string, mode int, perm uint32) (fd syscall.Handle, err error) {
+	if len(path) == 0 {
+		return syscall.InvalidHandle, syscall.ERROR_FILE_NOT_FOUND
+	}
+	pathp, err := syscall.UTF16PtrFromString(path)
+	if err != nil {
+		return syscall.InvalidHandle, err
+	}
+	var access uint32
+	switch mode & (syscall.O_RDONLY | syscall.O_WRONLY | syscall.O_RDWR) {
+	case syscall.O_RDONLY:
+		access = syscall.GENERIC_READ
+	case syscall.O_WRONLY:
+		access = syscall.GENERIC_WRITE
+	case syscall.O_RDWR:
+		access = syscall.GENERIC_READ | syscall.GENERIC_WRITE
+	}
+	if mode&syscall.O_CREAT != 0 {
+		access |= syscall.GENERIC_WRITE
+	}
+	if mode&syscall.O_APPEND != 0 {
+		access &^= syscall.GENERIC_WRITE
+		access |= syscall.FILE_APPEND_DATA
+	}
+	sharemode := uint32(syscall.FILE_SHARE_READ | syscall.FILE_SHARE_WRITE | syscall.FILE_SHARE_DELETE)
+	var createmode uint32
+	switch {
+	case mode&(syscall.O_CREAT|syscall.O_EXCL) == (syscall.O_CREAT | syscall.O_EXCL):
+		createmode = syscall.CREATE_NEW
+	case mode&(syscall.O_CREAT|syscall.O_TRUNC) == (syscall.O_CREAT | syscall.O_TRUNC):
+		createmode = syscall.CREATE_ALWAYS
+	case mode&syscall.O_CREAT == syscall.O_CREAT:
+		createmode = syscall.OPEN_ALWAYS
+	case mode&syscall.O_TRUNC == syscall.O_TRUNC:
+		createmode = syscall.TRUNCATE_EXISTING
+	default:
+		createmode = syscall.OPEN_EXISTING
+	}
+	var attrs uint32 = syscall.FILE_ATTRIBUTE_NORMAL
+	if perm&syscall.S_IWRITE == 0 {
+		attrs = syscall.FILE_ATTRIBUTE_READONLY
+	}
+	if createmode == syscall.OPEN_EXISTING && access == syscall.GENERIC_READ {
+		// Necessary for opening directory handles.
+		attrs |= syscall.FILE_FLAG_BACKUP_SEMANTICS
+	}
+	return syscall.CreateFile(pathp, access, sharemode, nil, createmode, attrs, 0)
+}

vfs/readervfs/README.md

@@ -0,0 +1,5 @@
+# Go `"reader"` SQLite VFS
+
+This package implements a `"reader"` SQLite VFS
+that allows accessing any [`io.ReaderAt`](https://pkg.go.dev/io#ReaderAt)
+as an immutable SQLite database.

vfs/readervfs/api.go

@@ -0,0 +1,84 @@
+// Package readervfs implements an SQLite VFS for immutable databases.
+//
+// The "reader" [vfs.VFS] permits accessing any [io.ReaderAt]
+// as an immutable SQLite database.
+//
+// Importing package readervfs registers the VFS.
+//
+//	import _ "github.com/ncruces/go-sqlite3/vfs/readervfs"
+package readervfs
+
+import (
+	"io"
+	"io/fs"
+	"sync"
+
+	"github.com/ncruces/go-sqlite3"
+	"github.com/ncruces/go-sqlite3/vfs"
+)
+
+func init() {
+	vfs.Register("reader", readerVFS{})
+}
+
+var (
+	readerMtx sync.RWMutex
+	// +checklocks:readerMtx
+	readerDBs = map[string]SizeReaderAt{}
+)
+
+// Create creates an immutable database from reader.
+// The caller should ensure that data from reader does not mutate,
+// otherwise SQLite might return incorrect query results and/or [sqlite3.CORRUPT] errors.
+func Create(name string, reader SizeReaderAt) {
+	readerMtx.Lock()
+	defer readerMtx.Unlock()
+	readerDBs[name] = reader
+}
+
+// Delete deletes a shared memory database.
+func Delete(name string) {
+	readerMtx.Lock()
+	defer readerMtx.Unlock()
+	delete(readerDBs, name)
+}
+
+// A SizeReaderAt is a ReaderAt with a Size method.
+// Use [NewSizeReaderAt] to adapt different Size interfaces.
+type SizeReaderAt interface {
+	Size() (int64, error)
+	io.ReaderAt
+}
+
+// NewSizeReaderAt returns a SizeReaderAt given an io.ReaderAt
+// that implements one of:
+//   - Size() (int64, error)
+//   - Size() int64
+//   - Len() int
+//   - Stat() (fs.FileInfo, error)
+//   - Seek(offset int64, whence int) (int64, error)
+func NewSizeReaderAt(r io.ReaderAt) SizeReaderAt {
+	return sizer{r}
+}
+
+type sizer struct{ io.ReaderAt }
+
+func (s sizer) Size() (int64, error) {
+	switch s := s.ReaderAt.(type) {
+	case interface{ Size() (int64, error) }:
+		return s.Size()
+	case interface{ Size() int64 }:
+		return s.Size(), nil
+	case interface{ Len() int }:
+		return int64(s.Len()), nil
+	case interface{ Stat() (fs.FileInfo, error) }:
+		fi, err := s.Stat()
+		if err != nil {
+			return 0, err
+		}
+		return fi.Size(), nil
+	case io.Seeker:
+		return s.Seek(0, io.SeekEnd)
+	}
+	return 0, sqlite3.IOERR_SEEK
+}