Docs.

Bumps [actions/setup-go](https://github.com/actions/setup-go) from 5 to 6.
- [Release notes](https://github.com/actions/setup-go/releases)
- [Commits](https://github.com/actions/setup-go/compare/v5...v6)

---
updated-dependencies:
- dependency-name: actions/setup-go
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/libc.yml

@@ -14,8 +14,8 @@ jobs:
     runs-on: ${{ matrix.os }}
 
     steps:
-    - uses: actions/checkout@v4
-    - uses: actions/setup-go@v5
+    - uses: actions/checkout@v5
+    - uses: actions/setup-go@v6
       with: { go-version: stable }
 
     - name: Benchmark

.github/workflows/repro.yml

@@ -17,13 +17,13 @@ jobs:
 
     steps:
     - uses: ilammy/msvc-dev-cmd@v1
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
 
     - name: Build
       shell: bash
       run: .github/workflows/repro.sh
 
-    - uses: actions/attest-build-provenance@v2
+    - uses: actions/attest-build-provenance@v3
       if: matrix.os == 'ubuntu-latest'
       with:
         subject-path: |

.github/workflows/test.yml

@@ -30,8 +30,8 @@ jobs:
       contents: write
 
     steps:
-    - uses: actions/checkout@v4
-    - uses: actions/setup-go@v5
+    - uses: actions/checkout@v5
+    - uses: actions/setup-go@v6
       with: { go-version: stable }
 
     - name: Format
@@ -98,14 +98,14 @@ jobs:
       matrix:
         os:
           - name: freebsd
-            version: '14.2'
+            version: '14.3'
             flags: '-test.v'
           - name: netbsd
             version: '10.1'
             flags: '-test.v'
           - name: freebsd
             arch: arm64
-            version: '14.2'
+            version: '14.3'
             flags: '-test.v -test.short'
           - name: netbsd
             arch: arm64
@@ -118,7 +118,7 @@ jobs:
     needs: test
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
 
     - name: Build
       env:
@@ -128,7 +128,7 @@ jobs:
       run: .github/workflows/build-test.sh
 
     - name: Test
-      uses: cross-platform-actions/action@v0.28.0
+      uses: cross-platform-actions/action@v0.29.0
       with:
         operating_system: ${{ matrix.os.name }}
         architecture: ${{ matrix.os.arch }}
@@ -155,7 +155,7 @@ jobs:
     needs: test
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
 
     - name: Build
       env:
@@ -174,8 +174,8 @@ jobs:
 
     steps:
     - uses: bytecodealliance/actions/wasmtime/setup@v1
-    - uses: actions/checkout@v4
-    - uses: actions/setup-go@v5
+    - uses: actions/checkout@v5
+    - uses: actions/setup-go@v6
       with: { go-version: stable }
 
     - name: Set path
@@ -195,8 +195,8 @@ jobs:
 
     steps:
     - uses: docker/setup-qemu-action@v3
-    - uses: actions/checkout@v4
-    - uses: actions/setup-go@v5
+    - uses: actions/checkout@v5
+    - uses: actions/setup-go@v6
       with: { go-version: stable }
 
     - name: Test 386 (32-bit)
@@ -216,8 +216,8 @@ jobs:
     needs: test
 
     steps:
-    - uses: actions/checkout@v4
-    - uses: actions/setup-go@v5
+    - uses: actions/checkout@v5
+    - uses: actions/setup-go@v6
       with: { go-version: stable }
 
     - name: Test
@@ -228,8 +228,8 @@ jobs:
     needs: test
 
     steps:
-    - uses: actions/checkout@v4
-    - uses: actions/setup-go@v5
+    - uses: actions/checkout@v5
+    - uses: actions/setup-go@v6
       with: { go-version: stable }
 
     - name: Test

conn.go

@@ -444,20 +444,27 @@ func (c *Conn) Status(op DBStatus, reset bool) (current, highwater int, err erro
 // https://sqlite.org/c3ref/table_column_metadata.html
 func (c *Conn) TableColumnMetadata(schema, table, column string) (declType, collSeq string, notNull, primaryKey, autoInc bool, err error) {
 	defer c.arena.mark()()
-
-	var schemaPtr, columnPtr ptr_t
-	declTypePtr := c.arena.new(ptrlen)
-	collSeqPtr := c.arena.new(ptrlen)
-	notNullPtr := c.arena.new(ptrlen)
-	autoIncPtr := c.arena.new(ptrlen)
-	primaryKeyPtr := c.arena.new(ptrlen)
+	var (
+		declTypePtr   ptr_t
+		collSeqPtr    ptr_t
+		notNullPtr    ptr_t
+		primaryKeyPtr ptr_t
+		autoIncPtr    ptr_t
+		columnPtr     ptr_t
+		schemaPtr     ptr_t
+	)
+	if column != "" {
+		declTypePtr = c.arena.new(ptrlen)
+		collSeqPtr = c.arena.new(ptrlen)
+		notNullPtr = c.arena.new(ptrlen)
+		primaryKeyPtr = c.arena.new(ptrlen)
+		autoIncPtr = c.arena.new(ptrlen)
+		columnPtr = c.arena.string(column)
+	}
 	if schema != "" {
 		schemaPtr = c.arena.string(schema)
 	}
 	tablePtr := c.arena.string(table)
-	if column != "" {
-		columnPtr = c.arena.string(column)
-	}
 
 	rc := res_t(c.call("sqlite3_table_column_metadata", stk_t(c.handle),
 		stk_t(schemaPtr), stk_t(tablePtr), stk_t(columnPtr),

context.go

@@ -1,7 +1,6 @@
 package sqlite3
 
 import (
-	"encoding/json"
 	"errors"
 	"math"
 	"time"
@@ -173,21 +172,6 @@ func (ctx Context) ResultPointer(ptr any) {
 		stk_t(ctx.handle), stk_t(valPtr))
 }
 
-// ResultJSON sets the result of the function to the JSON encoding of value.
-//
-// https://sqlite.org/c3ref/result_blob.html
-func (ctx Context) ResultJSON(value any) {
-	err := json.NewEncoder(callbackWriter(func(p []byte) (int, error) {
-		ctx.ResultRawText(p[:len(p)-1]) // remove the newline
-		return 0, nil
-	})).Encode(value)
-
-	if err != nil {
-		ctx.ResultError(err)
-		return // notest
-	}
-}
-
 // ResultValue sets the result of the function to a copy of [Value].
 //
 // https://sqlite.org/c3ref/result_blob.html

driver/driver.go

@@ -604,26 +604,27 @@ func (r resultRowsAffected) RowsAffected() (int64, error) {
 	return int64(r), nil
 }
 
-type rows struct {
-	ctx context.Context
-	*stmt
-	names []string
-	types []string
-	nulls []bool
-	scans []scantype
-}
-
 type scantype byte
 
 const (
-	_ANY  scantype = iota
-	_INT  scantype = scantype(sqlite3.INTEGER)
-	_REAL scantype = scantype(sqlite3.FLOAT)
-	_TEXT scantype = scantype(sqlite3.TEXT)
-	_BLOB scantype = scantype(sqlite3.BLOB)
-	_NULL scantype = scantype(sqlite3.NULL)
-	_BOOL scantype = iota
+	_ANY scantype = iota
+	_INT
+	_REAL
+	_TEXT
+	_BLOB
+	_NULL
+	_BOOL
 	_TIME
+	_NOT_NULL
+)
+
+var (
+	_ [0]struct{} = [scantype(sqlite3.INTEGER) - _INT]struct{}{}
+	_ [0]struct{} = [scantype(sqlite3.FLOAT) - _REAL]struct{}{}
+	_ [0]struct{} = [scantype(sqlite3.TEXT) - _TEXT]struct{}{}
+	_ [0]struct{} = [scantype(sqlite3.BLOB) - _BLOB]struct{}{}
+	_ [0]struct{} = [scantype(sqlite3.NULL) - _NULL]struct{}{}
+	_ [0]struct{} = [_NOT_NULL & (_NOT_NULL - 1)]struct{}{}
 )
 
 func scanFromDecl(decl string) scantype {
@@ -648,10 +649,20 @@ func scanFromDecl(decl string) scantype {
 	return _ANY
 }
 
+type rows struct {
+	ctx context.Context
+	*stmt
+	names []string
+	types []string
+	scans []scantype
+	dest  []driver.Value
+}
+
 var (
 	// Ensure these interfaces are implemented:
 	_ driver.RowsColumnTypeDatabaseTypeName = &rows{}
 	_ driver.RowsColumnTypeNullable         = &rows{}
+	// _ driver.RowsColumnScanner           = &rows{}
 )
 
 func (r *rows) Close() error {
@@ -674,34 +685,36 @@ func (r *rows) Columns() []string {
 
 func (r *rows) scanType(index int) scantype {
 	if r.scans == nil {
-		count := r.Stmt.ColumnCount()
+		count := len(r.names)
 		scans := make([]scantype, count)
 		for i := range scans {
 			scans[i] = scanFromDecl(strings.ToUpper(r.Stmt.ColumnDeclType(i)))
 		}
 		r.scans = scans
 	}
-	return r.scans[index]
+	return r.scans[index] &^ _NOT_NULL
 }
 
 func (r *rows) loadColumnMetadata() {
-	if r.nulls == nil {
+	if r.types == nil {
 		c := r.Stmt.Conn()
-		count := r.Stmt.ColumnCount()
-		nulls := make([]bool, count)
+		count := len(r.names)
 		types := make([]string, count)
 		scans := make([]scantype, count)
-		for i := range nulls {
+		for i := range types {
+			var notnull bool
 			if col := r.Stmt.ColumnOriginName(i); col != "" {
-				types[i], _, nulls[i], _, _, _ = c.TableColumnMetadata(
+				types[i], _, notnull, _, _, _ = c.TableColumnMetadata(
 					r.Stmt.ColumnDatabaseName(i),
 					r.Stmt.ColumnTableName(i),
 					col)
 				types[i] = strings.ToUpper(types[i])
 				scans[i] = scanFromDecl(types[i])
+				if notnull {
+					scans[i] |= _NOT_NULL
+				}
 			}
 		}
-		r.nulls = nulls
 		r.types = types
 		r.scans = scans
 	}
@@ -720,15 +733,13 @@ func (r *rows) ColumnTypeDatabaseTypeName(index int) string {
 
 func (r *rows) ColumnTypeNullable(index int) (nullable, ok bool) {
 	r.loadColumnMetadata()
-	if r.nulls[index] {
-		return false, true
-	}
-	return true, false
+	nullable = r.scans[index]&^_NOT_NULL == 0
+	return nullable, !nullable
 }
 
 func (r *rows) ColumnTypeScanType(index int) (typ reflect.Type) {
 	r.loadColumnMetadata()
-	scan := r.scans[index]
+	scan := r.scans[index] &^ _NOT_NULL
 
 	if r.Stmt.Busy() {
 		// SQLite is dynamically typed and we now have a row.
@@ -740,7 +751,7 @@ func (r *rows) ColumnTypeScanType(index int) (typ reflect.Type) {
 		switch {
 		case scan == _TIME && val != _BLOB && val != _NULL:
 			t := r.Stmt.ColumnTime(index, r.tmRead)
-			useValType = t == time.Time{}
+			useValType = t.IsZero()
 		case scan == _BOOL && val == _INT:
 			i := r.Stmt.ColumnInt64(index)
 			useValType = i != 0 && i != 1
@@ -771,6 +782,7 @@ func (r *rows) ColumnTypeScanType(index int) (typ reflect.Type) {
 }
 
 func (r *rows) Next(dest []driver.Value) error {
+	r.dest = nil
 	c := r.Stmt.Conn()
 	if old := c.SetInterrupt(r.ctx); old != r.ctx {
 		defer c.SetInterrupt(old)
@@ -789,18 +801,7 @@ func (r *rows) Next(dest []driver.Value) error {
 	}
 	for i := range dest {
 		scan := r.scanType(i)
-		switch v := dest[i].(type) {
-		case int64:
-			if scan == _BOOL {
-				switch v {
-				case 1:
-					dest[i] = true
-				case 0:
-					dest[i] = false
-				}
-				continue
-			}
-		case []byte:
+		if v, ok := dest[i].([]byte); ok {
 			if len(v) == cap(v) { // a BLOB
 				continue
 			}
@@ -815,18 +816,49 @@ func (r *rows) Next(dest []driver.Value) error {
 				}
 			}
 			dest[i] = string(v)
-		case float64:
-			break
-		default:
-			continue
 		}
-		if scan == _TIME {
+		switch scan {
+		case _TIME:
 			t, err := r.tmRead.Decode(dest[i])
 			if err == nil {
 				dest[i] = t
-				continue
+			}
+		case _BOOL:
+			switch dest[i] {
+			case int64(0):
+				dest[i] = false
+			case int64(1):
+				dest[i] = true
 			}
 		}
 	}
+	r.dest = dest
 	return nil
 }
+
+func (r *rows) ScanColumn(dest any, index int) (err error) {
+	// notest // Go 1.26
+	var tm *time.Time
+	var ok *bool
+	switch d := dest.(type) {
+	case *time.Time:
+		tm = d
+	case *sql.NullTime:
+		tm = &d.Time
+		ok = &d.Valid
+	case *sql.Null[time.Time]:
+		tm = &d.V
+		ok = &d.Valid
+	default:
+		return driver.ErrSkip
+	}
+	value := r.dest[index]
+	*tm, err = r.tmRead.Decode(value)
+	if ok != nil {
+		*ok = err == nil
+		if value == nil {
+			return nil
+		}
+	}
+	return err
+}

driver/driver_test.go

@@ -8,6 +8,7 @@ import (
 	"math"
 	"net/url"
 	"reflect"
+	"strings"
 	"testing"
 	"time"
 
@@ -33,7 +34,7 @@ func Test_Open_error(t *testing.T) {
 func Test_Open_dir(t *testing.T) {
 	t.Parallel()
 
-	db, err := sql.Open("sqlite3", ".")
+	db, err := Open(".")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -50,11 +51,11 @@ func Test_Open_dir(t *testing.T) {
 
 func Test_Open_pragma(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t, url.Values{
+	dsn := memdb.TestDB(t, url.Values{
 		"_pragma": {"busy_timeout(1000)"},
 	})
 
-	db, err := sql.Open("sqlite3", tmp)
+	db, err := Open(dsn)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -72,11 +73,11 @@ func Test_Open_pragma(t *testing.T) {
 
 func Test_Open_pragma_invalid(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t, url.Values{
+	dsn := memdb.TestDB(t, url.Values{
 		"_pragma": {"busy_timeout 1000"},
 	})
 
-	db, err := sql.Open("sqlite3", tmp)
+	db, err := Open(dsn)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -100,12 +101,12 @@ func Test_Open_pragma_invalid(t *testing.T) {
 
 func Test_Open_txLock(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t, url.Values{
+	dsn := memdb.TestDB(t, url.Values{
 		"_txlock": {"exclusive"},
 		"_pragma": {"busy_timeout(1000)"},
 	})
 
-	db, err := sql.Open("sqlite3", tmp)
+	db, err := Open(dsn)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -136,11 +137,11 @@ func Test_Open_txLock(t *testing.T) {
 
 func Test_Open_txLock_invalid(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t, url.Values{
+	dsn := memdb.TestDB(t, url.Values{
 		"_txlock": {"xclusive"},
 	})
 
-	_, err := sql.Open("sqlite3", tmp+"_txlock=xclusive")
+	_, err := Open(dsn)
 	if err == nil {
 		t.Fatal("want error")
 	}
@@ -151,31 +152,28 @@ func Test_Open_txLock_invalid(t *testing.T) {
 
 func Test_BeginTx(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t, url.Values{
+	dsn := memdb.TestDB(t, url.Values{
 		"_txlock": {"exclusive"},
 		"_pragma": {"busy_timeout(0)"},
 	})
 
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	db, err := sql.Open("sqlite3", tmp)
+	db, err := Open(dsn)
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer db.Close()
 
-	_, err = db.BeginTx(ctx, &sql.TxOptions{Isolation: sql.LevelReadCommitted})
+	_, err = db.BeginTx(t.Context(), &sql.TxOptions{Isolation: sql.LevelReadCommitted})
 	if err.Error() != string(util.IsolationErr) {
 		t.Error("want isolationErr")
 	}
 
-	tx1, err := db.BeginTx(ctx, &sql.TxOptions{ReadOnly: true})
+	tx1, err := db.BeginTx(t.Context(), &sql.TxOptions{ReadOnly: true})
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	tx2, err := db.BeginTx(ctx, &sql.TxOptions{ReadOnly: true})
+	tx2, err := db.BeginTx(t.Context(), &sql.TxOptions{ReadOnly: true})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -201,9 +199,9 @@ func Test_BeginTx(t *testing.T) {
 
 func Test_nested_context(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	db, err := sql.Open("sqlite3", tmp)
+	db, err := Open(dsn)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -236,7 +234,7 @@ func Test_nested_context(t *testing.T) {
 
 	want(outer, 0)
 
-	ctx, cancel := context.WithCancel(context.Background())
+	ctx, cancel := context.WithCancel(t.Context())
 	defer cancel()
 
 	inner, err := tx.QueryContext(ctx, `SELECT value FROM generate_series(0)`)
@@ -259,9 +257,9 @@ func Test_nested_context(t *testing.T) {
 
 func Test_Prepare(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	db, err := sql.Open("sqlite3", tmp)
+	db, err := Open(dsn)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -300,24 +298,21 @@ func Test_Prepare(t *testing.T) {
 
 func Test_QueryRow_named(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	db, err := sql.Open("sqlite3", tmp)
+	db, err := Open(dsn)
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer db.Close()
 
-	conn, err := db.Conn(ctx)
+	conn, err := db.Conn(t.Context())
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer conn.Close()
 
-	stmt, err := conn.PrepareContext(ctx, `SELECT ?, ?5, :AAA, @AAA, $AAA`)
+	stmt, err := conn.PrepareContext(t.Context(), `SELECT ?, ?5, :AAA, @AAA, $AAA`)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -353,9 +348,9 @@ func Test_QueryRow_named(t *testing.T) {
 
 func Test_QueryRow_blob_null(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	db, err := sql.Open("sqlite3", tmp)
+	db, err := Open(dsn)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -390,11 +385,11 @@ func Test_time(t *testing.T) {
 
 	for _, fmt := range []string{"auto", "sqlite", "rfc3339", time.ANSIC} {
 		t.Run(fmt, func(t *testing.T) {
-			tmp := memdb.TestDB(t, url.Values{
+			dsn := memdb.TestDB(t, url.Values{
 				"_timefmt": {fmt},
 			})
 
-			db, err := sql.Open("sqlite3", tmp)
+			db, err := Open(dsn)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -437,9 +432,9 @@ func Test_ColumnType_ScanType(t *testing.T) {
 	)
 
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	db, err := sql.Open("sqlite3", tmp)
+	db, err := Open(dsn)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -526,6 +521,39 @@ func Test_ColumnType_ScanType(t *testing.T) {
 	}
 }
 
+func Test_rows_ScanColumn(t *testing.T) {
+	t.Parallel()
+	dsn := memdb.TestDB(t)
+
+	db, err := Open(dsn)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+
+	var tm time.Time
+	err = db.QueryRow(`SELECT NULL`).Scan(&tm)
+	if err == nil {
+		t.Error("want error")
+	}
+	// Go 1.26
+	err = db.QueryRow(`SELECT datetime()`).Scan(&tm)
+	if err != nil && !strings.HasPrefix(err.Error(), "sql: Scan error") {
+		t.Error(err)
+	}
+
+	var nt sql.NullTime
+	err = db.QueryRow(`SELECT NULL`).Scan(&nt)
+	if err != nil {
+		t.Error(err)
+	}
+	// Go 1.26
+	err = db.QueryRow(`SELECT datetime()`).Scan(&nt)
+	if err != nil && !strings.HasPrefix(err.Error(), "sql: Scan error") {
+		t.Error(err)
+	}
+}
+
 func Benchmark_loop(b *testing.B) {
 	db, err := Open(":memory:")
 	if err != nil {
@@ -539,12 +567,8 @@ func Benchmark_loop(b *testing.B) {
 		b.Fatal(err)
 	}
 
-	ctx, cancel := context.WithCancel(context.Background())
-	b.Cleanup(cancel)
-
-	b.ResetTimer()
-	for range b.N {
-		_, err := db.ExecContext(ctx,
+	for b.Loop() {
+		_, err := db.ExecContext(b.Context(),
 			`WITH RECURSIVE c(x) AS (VALUES(1) UNION ALL SELECT x+1 FROM c WHERE x < 1000000) SELECT x FROM c;`)
 		if err != nil {
 			b.Fatal(err)

driver/util_test.go

@@ -1,7 +1,6 @@
 package driver
 
 import (
-	"context"
 	"database/sql/driver"
 	"slices"
 	"testing"
@@ -56,7 +55,7 @@ func Fuzz_notWhitespace(f *testing.F) {
 			t.SkipNow()
 		}
 
-		c, err := db.Conn(context.Background())
+		c, err := db.Conn(t.Context())
 		if err != nil {
 			t.Fatal(err)
 		}

embed/README.md

@@ -1,6 +1,6 @@
 # Embeddable Wasm build of SQLite
 
-This folder includes an embeddable Wasm build of SQLite 3.50.2 for use with
+This folder includes an embeddable Wasm build of SQLite 3.50.4 for use with
 [`github.com/ncruces/go-sqlite3`](https://pkg.go.dev/github.com/ncruces/go-sqlite3).
 
 The following optional features are compiled in:

embed/bcw2/build.sh

@@ -7,16 +7,18 @@ ROOT=../../
 BINARYEN="$ROOT/tools/binaryen/bin"
 WASI_SDK="$ROOT/tools/wasi-sdk/bin"
 
-trap 'rm -rf build/ sqlite/ bcw2.tmp' EXIT
+trap 'rm -rf sqlite/ build/ bcw2.tmp' EXIT
 
+mkdir -p sqlite/
 mkdir -p build/ext/
 cp "$ROOT"/sqlite3/*.[ch] build/
 cp "$ROOT"/sqlite3/*.patch build/
+cd sqlite/
 
-# https://sqlite.org/src/info/a6f6fbe6173de8a2
-curl -# https://sqlite.org/src/tarball/sqlite.tar.gz?r=a6f6fbe617 | tar xz
+# https://sqlite.org/src/info/ba2174bdca7d1d1a
+curl -#L https://github.com/sqlite/sqlite/archive/b46738f.tar.gz | tar xz --strip-components=1
+# curl -#L https://sqlite.org/src/tarball/sqlite.tar.gz?r=ba2174bdca | tar xz --strip-components=1
 
-cd sqlite
 if [[ "$OSTYPE" == "msys" || "$OSTYPE" == "cygwin" ]]; then
 	MSYS_NO_PATHCONV=1 nmake /f makefile.msc sqlite3.c "OPTS=-DSQLITE_ENABLE_UPDATE_DELETE_LIMIT -DSQLITE_ENABLE_ORDERED_SET_AGGREGATES"
 else
@@ -49,7 +51,8 @@ cd ~-
 	-mmutable-globals -mnontrapping-fptoint \
 	-msimd128 -mbulk-memory -msign-ext \
 	-mreference-types -mmultivalue \
-	-fno-stack-protector -fno-stack-clash-protection \
+	-mno-extended-const \
+	-fno-stack-protector \
 	-Wl,--stack-first \
 	-Wl,--import-undefined \
 	-Wl,--initial-memory=327680 \
@@ -59,8 +62,9 @@ cd ~-
 	$(awk '{print "-Wl,--export="$0}' ../exports.txt)
 
 "$BINARYEN/wasm-ctor-eval" -g -c _initialize bcw2.wasm -o bcw2.tmp
-"$BINARYEN/wasm-opt" -g --strip --strip-producers -c -O3 \
-	bcw2.tmp -o bcw2.wasm --low-memory-unused \
+"$BINARYEN/wasm-opt" -g bcw2.tmp -o bcw2.wasm \
+	--low-memory-unused --gufa --generate-global-effects --converge -O3 \
 	--enable-mutable-globals --enable-nontrapping-float-to-int \
 	--enable-simd --enable-bulk-memory --enable-sign-ext \
-	--enable-reference-types --enable-multivalue
+	--enable-reference-types --enable-multivalue \
+	--strip --strip-producers

embed/bcw2/go.mod

@@ -1,14 +1,12 @@
 module github.com/ncruces/go-sqlite3/embed/bcw2
 
-go 1.23.0
+go 1.24.0
 
-toolchain go1.24.0
-
-require github.com/ncruces/go-sqlite3 v0.26.3
+require github.com/ncruces/go-sqlite3 v0.29.0
 
 require (
 	github.com/ncruces/julianday v1.0.0 // indirect
 	github.com/ncruces/sort v0.1.5 // indirect
 	github.com/tetratelabs/wazero v1.9.0 // indirect
-	golang.org/x/sys v0.34.0 // indirect
+	golang.org/x/sys v0.36.0 // indirect
 )

embed/bcw2/go.sum

@@ -1,12 +1,12 @@
-github.com/ncruces/go-sqlite3 v0.26.3 h1:WFkQj4KNMhbqiBPGDrVpK74w1DzcxQu3wYpmdWAvfYM=
-github.com/ncruces/go-sqlite3 v0.26.3/go.mod h1:XFTPtFIo1DmGCh+XVP8KGn9b/o2f+z0WZuT09x2N6eo=
+github.com/ncruces/go-sqlite3 v0.29.0 h1:1tsLiagCoqZEfcHDeKsNSv5jvrY/Iu393pAnw2wLNJU=
+github.com/ncruces/go-sqlite3 v0.29.0/go.mod h1:r1hSvYKPNJ+OlUA1O3r8o9LAawzPAlqeZiIdxTBBBJ0=
 github.com/ncruces/julianday v1.0.0 h1:fH0OKwa7NWvniGQtxdJRxAgkBMolni2BjDHaWTxqt7M=
 github.com/ncruces/julianday v1.0.0/go.mod h1:Dusn2KvZrrovOMJuOt0TNXL6tB7U2E8kvza5fFc9G7g=
 github.com/ncruces/sort v0.1.5 h1:fiFWXXAqKI8QckPf/6hu/bGFwcEPrirIOFaJqWujs4k=
 github.com/ncruces/sort v0.1.5/go.mod h1:obJToO4rYr6VWP0Uw5FYymgYGt3Br4RXcs/JdKaXAPk=
 github.com/tetratelabs/wazero v1.9.0 h1:IcZ56OuxrtaEz8UYNRHBrUa9bYeX9oVY93KspZZBf/I=
 github.com/tetratelabs/wazero v1.9.0/go.mod h1:TSbcXCfFP0L2FGkRPxHphadXPjo1T6W+CseNNY7EkjM=
-golang.org/x/sys v0.34.0 h1:H5Y5sJ2L2JRdyv7ROF1he/lPdvFsd0mJHFw2ThKHxLA=
-golang.org/x/sys v0.34.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
-golang.org/x/text v0.26.0 h1:P42AVeLghgTYr4+xUnTRKDMqpar+PtX7KWuNQL21L8M=
-golang.org/x/text v0.26.0/go.mod h1:QK15LZJUUQVJxhz7wXgxSy/CJaTFjd0G+YLonydOVQA=
+golang.org/x/sys v0.36.0 h1:KVRy2GtZBrk1cBYA7MKu5bEZFxQk4NIDV6RLVcC8o0k=
+golang.org/x/sys v0.36.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/text v0.29.0 h1:1neNs90w9YzJ9BocxfsQNHKuAT4pkghyXc4nhZ6sJvk=
+golang.org/x/text v0.29.0/go.mod h1:7MhJOA9CD2qZyOKYazxdYMF85OwPdEr9jTtBpO7ydH4=

embed/build.sh

@@ -17,7 +17,8 @@ trap 'rm -f sqlite3.tmp' EXIT
 	-mmutable-globals -mnontrapping-fptoint \
 	-msimd128 -mbulk-memory -msign-ext \
 	-mreference-types -mmultivalue \
-	-fno-stack-protector -fno-stack-clash-protection \
+	-mno-extended-const \
+	-fno-stack-protector \
 	-Wl,--stack-first \
 	-Wl,--import-undefined \
 	-Wl,--initial-memory=327680 \
@@ -26,8 +27,9 @@ trap 'rm -f sqlite3.tmp' EXIT
 	$(awk '{print "-Wl,--export="$0}' exports.txt)
 
 "$BINARYEN/wasm-ctor-eval" -g -c _initialize sqlite3.wasm -o sqlite3.tmp
-"$BINARYEN/wasm-opt" -g --strip --strip-producers -c -O3 \
-	sqlite3.tmp -o sqlite3.wasm --low-memory-unused \
+"$BINARYEN/wasm-opt" -g sqlite3.tmp -o sqlite3.wasm \
+	--low-memory-unused --gufa --generate-global-effects --converge -O3 \
 	--enable-mutable-globals --enable-nontrapping-float-to-int \
 	--enable-simd --enable-bulk-memory --enable-sign-ext \
-	--enable-reference-types --enable-multivalue
+	--enable-reference-types --enable-multivalue \
+	--strip --strip-producers

embed/init_test.go

@@ -19,7 +19,7 @@ func Test_init(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if version != "3.50.2" {
+	if version != "3.50.4" {
 		t.Error(version)
 	}
 }

ext/README.md

@@ -38,11 +38,11 @@ you can load into your database connections.
 - [`github.com/ncruces/go-sqlite3/ext/zorder`](https://pkg.go.dev/github.com/ncruces/go-sqlite3/ext/zorder)
   maps multidimensional data to one dimension.
 
-### Pakages
+### Packages
 
 These packages may also be useful to work with SQLite:
 
 - [`github.com/ncruces/decimal`](https://pkg.go.dev/github.com/ncruces/decimal)
   decimal arithmetic.
 - [`github.com/ncruces/julianday`](https://pkg.go.dev/github.com/ncruces/julianday)
-  Julian day math.
+  Julian day math.

ext/array/array_test.go

@@ -88,9 +88,9 @@ func Example() {
 
 func Test_cursor_Column(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	db, err := driver.Open(tmp, array.Register)
+	db, err := driver.Open(dsn, array.Register)
 	if err != nil {
 		t.Fatal(err)
 	}

ext/fileio/fileio.go

@@ -18,7 +18,7 @@ func Register(db *sqlite3.Conn) error {
 	return RegisterFS(db, nil)
 }
 
-// Register registers SQL functions readfile, lsmode,
+// RegisterFS registers SQL functions readfile, lsmode,
 // and the table-valued function fsdir;
 // fsys will be used to read files and list directories.
 func RegisterFS(db *sqlite3.Conn, fsys fs.FS) error {

ext/fileio/fileio_test.go

@@ -17,9 +17,9 @@ import (
 
 func Test_lsmode(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	db, err := driver.Open(tmp, fileio.Register)
+	db, err := driver.Open(dsn, fileio.Register)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -53,9 +53,9 @@ func Test_readfile(t *testing.T) {
 
 	for _, fsys := range []fs.FS{nil, os.DirFS(".")} {
 		t.Run("", func(t *testing.T) {
-			tmp := memdb.TestDB(t)
+			dsn := memdb.TestDB(t)
 
-			db, err := driver.Open(tmp, func(c *sqlite3.Conn) error {
+			db, err := driver.Open(dsn, func(c *sqlite3.Conn) error {
 				fileio.RegisterFS(c, fsys)
 				return nil
 			})

ext/fileio/fsdir_test.go

@@ -21,9 +21,9 @@ func Test_fsdir(t *testing.T) {
 
 	for _, fsys := range []fs.FS{nil, os.DirFS(".")} {
 		t.Run("", func(t *testing.T) {
-			tmp := memdb.TestDB(t)
+			dsn := memdb.TestDB(t)
 
-			db, err := driver.Open(tmp, func(c *sqlite3.Conn) error {
+			db, err := driver.Open(dsn, func(c *sqlite3.Conn) error {
 				fileio.RegisterFS(c, fsys)
 				return nil
 			})

ext/fileio/write_test.go

@@ -15,9 +15,9 @@ import (
 
 func Test_writefile(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	db, err := driver.Open(tmp, Register)
+	db, err := driver.Open(dsn, Register)
 	if err != nil {
 		t.Fatal(err)
 	}

ext/hash/hash_test.go

@@ -4,6 +4,7 @@ import (
 	_ "crypto/md5"
 	_ "crypto/sha1"
 	_ "crypto/sha256"
+	_ "crypto/sha3"
 	_ "crypto/sha512"
 	"testing"
 
@@ -11,7 +12,6 @@ import (
 	_ "golang.org/x/crypto/blake2s"
 	_ "golang.org/x/crypto/md4"
 	_ "golang.org/x/crypto/ripemd160"
-	_ "golang.org/x/crypto/sha3"
 
 	"github.com/ncruces/go-sqlite3/driver"
 	_ "github.com/ncruces/go-sqlite3/embed"
@@ -21,7 +21,7 @@ import (
 
 func TestRegister(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
 	tests := []struct {
 		name string
@@ -55,7 +55,7 @@ func TestRegister(t *testing.T) {
 		{"blake2b('', 256)", "0E5751C026E543B2E8AB2EB06099DAA1D1E5DF47778F7787FAAB45CDF12FE3A8"},
 	}
 
-	db, err := driver.Open(tmp, Register)
+	db, err := driver.Open(dsn, Register)
 	if err != nil {
 		t.Fatal(err)
 	}

ext/ipaddr/ipaddr_test.go

@@ -12,9 +12,9 @@ import (
 
 func TestRegister(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	db, err := driver.Open(tmp, ipaddr.Register)
+	db, err := driver.Open(dsn, ipaddr.Register)
 	if err != nil {
 		t.Fatal(err)
 	}

ext/lines/lines_test.go

@@ -67,9 +67,9 @@ func Example() {
 
 func Test_lines(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	db, err := driver.Open(tmp, lines.Register)
+	db, err := driver.Open(dsn, lines.Register)
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -98,9 +98,9 @@ func Test_lines(t *testing.T) {
 
 func Test_lines_error(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	db, err := driver.Open(tmp, lines.Register)
+	db, err := driver.Open(dsn, lines.Register)
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -123,9 +123,9 @@ func Test_lines_error(t *testing.T) {
 
 func Test_lines_read(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	db, err := driver.Open(tmp, lines.Register)
+	db, err := driver.Open(dsn, lines.Register)
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -155,9 +155,9 @@ func Test_lines_read(t *testing.T) {
 
 func Test_lines_test(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	db, err := driver.Open(tmp, lines.Register)
+	db, err := driver.Open(dsn, lines.Register)
 	if err != nil {
 		log.Fatal(err)
 	}

ext/regexp/regexp_test.go

@@ -15,9 +15,9 @@ import (
 
 func TestRegister(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	db, err := driver.Open(tmp, Register)
+	db, err := driver.Open(dsn, Register)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -80,9 +80,9 @@ func TestRegister(t *testing.T) {
 
 func TestRegister_errors(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	db, err := driver.Open(tmp, Register)
+	db, err := driver.Open(dsn, Register)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -107,9 +107,9 @@ func TestRegister_errors(t *testing.T) {
 
 func TestRegister_pointer(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	db, err := driver.Open(tmp, Register)
+	db, err := driver.Open(dsn, Register)
 	if err != nil {
 		t.Fatal(err)
 	}

ext/serdes/serdes.go

@@ -2,9 +2,8 @@
 package serdes
 
 import (
-	"io"
-
 	"github.com/ncruces/go-sqlite3"
+	"github.com/ncruces/go-sqlite3/util/vfsutil"
 	"github.com/ncruces/go-sqlite3/vfs"
 )
 
@@ -14,16 +13,16 @@ func init() {
 	vfs.Register(vfsName, sliceVFS{})
 }
 
-var fileToOpen = make(chan *sliceFile, 1)
+var fileToOpen = make(chan *[]byte, 1)
 
 // Serialize backs up a database into a byte slice.
 //
 // https://sqlite.org/c3ref/serialize.html
 func Serialize(db *sqlite3.Conn, schema string) ([]byte, error) {
-	var file sliceFile
+	var file []byte
 	fileToOpen <- &file
-	err := db.Backup(schema, "file:serdes.db?vfs="+vfsName)
-	return file.data, err
+	err := db.Backup(schema, "file:serdes.db?nolock=1&vfs="+vfsName)
+	return file, err
 }
 
 // Deserialize restores a database from a byte slice,
@@ -41,8 +40,8 @@ func Serialize(db *sqlite3.Conn, schema string) ([]byte, error) {
 // ["memdb"]: https://pkg.go.dev/github.com/ncruces/go-sqlite3/vfs/memdb
 // ["reader"]: https://pkg.go.dev/github.com/ncruces/go-sqlite3/vfs/readervfs
 func Deserialize(db *sqlite3.Conn, schema string, data []byte) error {
-	fileToOpen <- &sliceFile{data}
-	return db.Restore(schema, "file:serdes.db?vfs="+vfsName)
+	fileToOpen <- &data
+	return db.Restore(schema, "file:serdes.db?immutable=1&vfs="+vfsName)
 }
 
 type sliceVFS struct{}
@@ -53,14 +52,14 @@ func (sliceVFS) Open(name string, flags vfs.OpenFlag) (vfs.File, vfs.OpenFlag, e
 	}
 	select {
 	case file := <-fileToOpen:
-		return file, flags | vfs.OPEN_MEMORY, nil
+		return (*vfsutil.SliceFile)(file), flags | vfs.OPEN_MEMORY, nil
 	default:
 		return nil, flags, sqlite3.MISUSE
 	}
 }
 
 func (sliceVFS) Delete(name string, dirSync bool) error {
-	// notest // OPEN_MEMORY
+	// notest // no journals to delete
 	return sqlite3.IOERR_DELETE
 }
 
@@ -71,70 +70,3 @@ func (sliceVFS) Access(name string, flag vfs.AccessFlag) (bool, error) {
 func (sliceVFS) FullPathname(name string) (string, error) {
 	return name, nil
 }
-
-type sliceFile struct{ data []byte }
-
-func (f *sliceFile) ReadAt(b []byte, off int64) (n int, err error) {
-	if d := f.data; off < int64(len(d)) {
-		n = copy(b, d[off:])
-	}
-	if n == 0 {
-		err = io.EOF
-	}
-	return
-}
-
-func (f *sliceFile) WriteAt(b []byte, off int64) (n int, err error) {
-	if d := f.data; off > int64(len(d)) {
-		f.data = append(d, make([]byte, off-int64(len(d)))...)
-	}
-	d := append(f.data[:off], b...)
-	if len(d) > len(f.data) {
-		f.data = d
-	}
-	return len(b), nil
-}
-
-func (f *sliceFile) Size() (int64, error) {
-	return int64(len(f.data)), nil
-}
-
-func (f *sliceFile) Truncate(size int64) error {
-	if d := f.data; size < int64(len(d)) {
-		f.data = d[:size]
-	}
-	return nil
-}
-
-func (f *sliceFile) SizeHint(size int64) error {
-	if d := f.data; size > int64(len(d)) {
-		f.data = append(d, make([]byte, size-int64(len(d)))...)
-	}
-	return nil
-}
-
-func (*sliceFile) Close() error { return nil }
-
-func (*sliceFile) Sync(flag vfs.SyncFlag) error { return nil }
-
-func (*sliceFile) Lock(lock vfs.LockLevel) error { return nil }
-
-func (*sliceFile) Unlock(lock vfs.LockLevel) error { return nil }
-
-func (*sliceFile) CheckReservedLock() (bool, error) {
-	// notest // OPEN_MEMORY
-	return false, nil
-}
-
-func (*sliceFile) SectorSize() int {
-	// notest // IOCAP_POWERSAFE_OVERWRITE
-	return 0
-}
-
-func (*sliceFile) DeviceCharacteristics() vfs.DeviceCharacteristic {
-	return vfs.IOCAP_ATOMIC |
-		vfs.IOCAP_SAFE_APPEND |
-		vfs.IOCAP_SEQUENTIAL |
-		vfs.IOCAP_POWERSAFE_OVERWRITE |
-		vfs.IOCAP_SUBPAGE_READ
-}

ext/serdes/serdes_test.go

@@ -1,6 +1,7 @@
 package serdes_test
 
 import (
+	_ "embed"
 	"errors"
 	"io"
 	"net/http"
@@ -11,7 +12,30 @@ import (
 	"github.com/ncruces/go-sqlite3/ext/serdes"
 )
 
-func TestDeserialize(t *testing.T) {
+//go:embed testdata/wal.db
+var walDB []byte
+
+func Test_wal(t *testing.T) {
+	db, err := sqlite3.Open("testdata/wal.db")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+
+	data, err := serdes.Serialize(db, "main")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	compareDBs(t, data, walDB)
+
+	err = serdes.Deserialize(db, "temp", walDB)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+func Test_northwind(t *testing.T) {
 	if testing.Short() {
 		t.Skip("skipping in short mode")
 	}
@@ -37,10 +61,14 @@ func TestDeserialize(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	if len(input) != len(output) {
+	compareDBs(t, input, output)
+}
+
+func compareDBs(t *testing.T, a, b []byte) {
+	if len(a) != len(b) {
 		t.Fatal("lengths are different")
 	}
-	for i := range input {
+	for i := range a {
 		// These may be different.
 		switch {
 		case 24 <= i && i < 28:
@@ -53,14 +81,14 @@ func TestDeserialize(t *testing.T) {
 			// SQLite version that wrote the file.
 			continue
 		}
-		if input[i] != output[i] {
-			t.Errorf("difference at %d: %d %d", i, input[i], output[i])
+		if a[i] != b[i] {
+			t.Errorf("difference at %d: %d %d", i, a[i], b[i])
 		}
 	}
 }
 
 func httpGet() ([]byte, error) {
-	res, err := http.Get("https://raw.githubusercontent.com/jpwhite3/northwind-SQLite3/refs/heads/main/dist/northwind.db")
+	res, err := http.Get("https://github.com/jpwhite3/northwind-SQLite3/raw/refs/heads/main/dist/northwind.db")
 	if err != nil {
 		return nil, err
 	}

ext/unicode/unicode.go

@@ -43,7 +43,7 @@ import (
 	"github.com/ncruces/go-sqlite3/internal/util"
 )
 
-// Set RegisterLike to false to not register a Unicode aware LIKE operator.
+// RegisterLike must be set to false to not register a Unicode aware LIKE operator.
 // Overriding the built-in LIKE operator disables the [LIKE optimization].
 //
 // [LIKE optimization]: https://sqlite.org/optoverview.html#the_like_optimization

ext/uuid/uuid.go

@@ -194,7 +194,7 @@ func timestamp(ctx sqlite3.Context, arg ...sqlite3.Value) {
 		switch u.Version() {
 		case 1, 2, 6, 7:
 			ctx.ResultTime(
-				time.Unix(u.Time().UnixTime()),
+				time.Unix(u.Time().UnixTime()).UTC(),
 				sqlite3.TimeFormatDefault)
 		}
 	}

ext/uuid/uuid_test.go

@@ -14,9 +14,9 @@ import (
 
 func Test_generate(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	db, err := driver.Open(tmp, Register)
+	db, err := driver.Open(dsn, Register)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -153,9 +153,9 @@ func Test_generate(t *testing.T) {
 
 func Test_convert(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	db, err := driver.Open(tmp, Register)
+	db, err := driver.Open(dsn, Register)
 	if err != nil {
 		t.Fatal(err)
 	}

ext/zorder/zorder.go

@@ -19,9 +19,9 @@ func Register(db *sqlite3.Conn) error {
 }
 
 func zorder(ctx sqlite3.Context, arg ...sqlite3.Value) {
-	var x [63]int64
-	if len(arg) > len(x) {
-		ctx.ResultError(util.ErrorString("zorder: too many parameters"))
+	var x [24]int64
+	if n := len(arg); n < 2 || n > 24 {
+		ctx.ResultError(util.ErrorString("zorder: needs between 2 and 24 dimensions"))
 		return
 	}
 	for i := range arg {
@@ -29,17 +29,15 @@ func zorder(ctx sqlite3.Context, arg ...sqlite3.Value) {
 	}
 
 	var z int64
-	if len(arg) > 0 {
-		for i := range x {
-			j := i % len(arg)
-			z |= (x[j] & 1) << i
-			x[j] >>= 1
-		}
+	for i := range 63 {
+		j := i % len(arg)
+		z |= (x[j] & 1) << i
+		x[j] >>= 1
 	}
 
 	for i := range arg {
 		if x[i] != 0 {
-			ctx.ResultError(util.ErrorString("zorder: parameter too large"))
+			ctx.ResultError(util.ErrorString("zorder: argument out of range"))
 			return
 		}
 	}
@@ -51,6 +49,19 @@ func unzorder(ctx sqlite3.Context, arg ...sqlite3.Value) {
 	n := arg[1].Int64()
 	z := arg[0].Int64()
 
+	if n < 2 || n > 24 {
+		ctx.ResultError(util.ErrorString("unzorder: needs between 2 and 24 dimensions"))
+		return
+	}
+	if i < 0 || i >= n {
+		ctx.ResultError(util.ErrorString("unzorder: index out of range"))
+		return
+	}
+	if z < 0 {
+		ctx.ResultError(util.ErrorString("unzorder: argument out of range"))
+		return
+	}
+
 	var k int
 	var x int64
 	for j := i; j < 63; j += n {

ext/zorder/zorder_test.go

@@ -12,11 +12,11 @@ import (
 	"github.com/ncruces/go-sqlite3/vfs/memdb"
 )
 
-func TestRegister_zorder(t *testing.T) {
+func Test_zorder(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	db, err := driver.Open(tmp, zorder.Register)
+	db, err := driver.Open(dsn, zorder.Register)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -57,11 +57,11 @@ func TestRegister_zorder(t *testing.T) {
 	}
 }
 
-func TestRegister_unzorder(t *testing.T) {
+func Test_unzorder(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	db, err := driver.Open(tmp, zorder.Register)
+	db, err := driver.Open(dsn, zorder.Register)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -85,11 +85,11 @@ func TestRegister_unzorder(t *testing.T) {
 	}
 }
 
-func TestRegister_error(t *testing.T) {
+func Test_zorder_error(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	db, err := driver.Open(tmp, zorder.Register)
+	db, err := driver.Open(dsn, zorder.Register)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -103,7 +103,7 @@ func TestRegister_error(t *testing.T) {
 
 	var buf strings.Builder
 	buf.WriteString("SELECT zorder(0")
-	for i := 1; i < 80; i++ {
+	for i := 1; i < 25; i++ {
 		buf.WriteByte(',')
 		buf.WriteString(strconv.Itoa(0))
 	}
@@ -113,3 +113,30 @@ func TestRegister_error(t *testing.T) {
 		t.Error("want error")
 	}
 }
+
+func Test_unzorder_error(t *testing.T) {
+	t.Parallel()
+	dsn := memdb.TestDB(t)
+
+	db, err := driver.Open(dsn, zorder.Register)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+
+	var got int64
+	err = db.QueryRow(`SELECT unzorder(-1, 2, 0)`).Scan(&got)
+	if err == nil {
+		t.Error("want error")
+	}
+
+	err = db.QueryRow(`SELECT unzorder(0, 2, 2)`).Scan(&got)
+	if err == nil {
+		t.Error("want error")
+	}
+
+	err = db.QueryRow(`SELECT unzorder(0, 25, 2)`).Scan(&got)
+	if err == nil {
+		t.Error("want error")
+	}
+}

func.go

@@ -59,7 +59,7 @@ func (c *Conn) CreateCollation(name string, fn CollatingFunction) error {
 	return c.error(rc)
 }
 
-// Collating function is the type of a collation callback.
+// CollatingFunction is the type of a collation callback.
 // Implementations must not retain a or b.
 type CollatingFunction func(a, b []byte) int
 
@@ -132,7 +132,7 @@ func (c *Conn) CreateWindowFunction(name string, nArg int, flag FunctionFlag, fn
 			if win, ok := agg.(WindowFunction); ok {
 				return win
 			}
-			return windowFunc{agg, name}
+			return agg
 		}))
 	}
 	rc := res_t(c.call("sqlite3_create_window_function_go",
@@ -307,13 +307,3 @@ func (a *aggregateFunc) Close() error {
 	a.stop()
 	return nil
 }
-
-type windowFunc struct {
-	AggregateFunction
-	name string
-}
-
-func (w windowFunc) Inverse(ctx Context, arg ...Value) {
-	// Implementing inverse allows certain queries that don't really need it to succeed.
-	ctx.ResultError(util.ErrorString(w.name + ": may not be used as a window function"))
-}

go.mod

@@ -1,23 +1,22 @@
 module github.com/ncruces/go-sqlite3
 
-go 1.23.0
-
-toolchain go1.24.0
+go 1.24.0
 
 require (
 	github.com/ncruces/julianday v1.0.0
-	github.com/ncruces/sort v0.1.5
+	github.com/ncruces/sort v0.1.6
+	github.com/ncruces/wbt v0.2.0
 	github.com/tetratelabs/wazero v1.9.0
-	golang.org/x/crypto v0.40.0
-	golang.org/x/sys v0.34.0
+	golang.org/x/sys v0.36.0
 )
 
 require (
 	github.com/dchest/siphash v1.2.3 // ext/bloom
 	github.com/google/uuid v1.6.0 // ext/uuid
 	github.com/psanford/httpreadat v0.1.0 // example
-	golang.org/x/sync v0.16.0 // test
-	golang.org/x/text v0.27.0 // ext/unicode
+	golang.org/x/crypto v0.42.0 // vfs/adiantum vfs/xts
+	golang.org/x/sync v0.17.0 // test
+	golang.org/x/text v0.29.0 // ext/unicode
 	lukechampine.com/adiantum v1.1.1 // vfs/adiantum
 )
 

go.sum

@@ -4,19 +4,21 @@ github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/ncruces/julianday v1.0.0 h1:fH0OKwa7NWvniGQtxdJRxAgkBMolni2BjDHaWTxqt7M=
 github.com/ncruces/julianday v1.0.0/go.mod h1:Dusn2KvZrrovOMJuOt0TNXL6tB7U2E8kvza5fFc9G7g=
-github.com/ncruces/sort v0.1.5 h1:fiFWXXAqKI8QckPf/6hu/bGFwcEPrirIOFaJqWujs4k=
-github.com/ncruces/sort v0.1.5/go.mod h1:obJToO4rYr6VWP0Uw5FYymgYGt3Br4RXcs/JdKaXAPk=
+github.com/ncruces/sort v0.1.6 h1:TrsJfGRH1AoWoaeB4/+gCohot9+cA6u/INaH5agIhNk=
+github.com/ncruces/sort v0.1.6/go.mod h1:obJToO4rYr6VWP0Uw5FYymgYGt3Br4RXcs/JdKaXAPk=
+github.com/ncruces/wbt v0.2.0 h1:Q9zlKOBSZc7Yy/R2cGa35g6RKUUE3BjNIW3tfGC4F04=
+github.com/ncruces/wbt v0.2.0/go.mod h1:DtF92amvMxH69EmBFUSFWRDAlo6hOEfoNQnClxj9C/c=
 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 v1.9.0 h1:IcZ56OuxrtaEz8UYNRHBrUa9bYeX9oVY93KspZZBf/I=
 github.com/tetratelabs/wazero v1.9.0/go.mod h1:TSbcXCfFP0L2FGkRPxHphadXPjo1T6W+CseNNY7EkjM=
-golang.org/x/crypto v0.40.0 h1:r4x+VvoG5Fm+eJcxMaY8CQM7Lb0l1lsmjGBQ6s8BfKM=
-golang.org/x/crypto v0.40.0/go.mod h1:Qr1vMER5WyS2dfPHAlsOj01wgLbsyWtFn/aY+5+ZdxY=
-golang.org/x/sync v0.16.0 h1:ycBJEhp9p4vXvUZNszeOq0kGTPghopOL8q0fq3vstxw=
-golang.org/x/sync v0.16.0/go.mod h1:1dzgHSNfp02xaA81J2MS99Qcpr2w7fw1gpm99rleRqA=
-golang.org/x/sys v0.34.0 h1:H5Y5sJ2L2JRdyv7ROF1he/lPdvFsd0mJHFw2ThKHxLA=
-golang.org/x/sys v0.34.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
-golang.org/x/text v0.27.0 h1:4fGWRpyh641NLlecmyl4LOe6yDdfaYNrGb2zdfo4JV4=
-golang.org/x/text v0.27.0/go.mod h1:1D28KMCvyooCX9hBiosv5Tz/+YLxj0j7XhWjpSUF7CU=
+golang.org/x/crypto v0.42.0 h1:chiH31gIWm57EkTXpwnqf8qeuMUi0yekh6mT2AvFlqI=
+golang.org/x/crypto v0.42.0/go.mod h1:4+rDnOTJhQCx2q7/j6rAN5XDw8kPjeaXEUR2eL94ix8=
+golang.org/x/sync v0.17.0 h1:l60nONMj9l5drqw6jlhIELNv9I0A4OFgRsG9k2oT9Ug=
+golang.org/x/sync v0.17.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
+golang.org/x/sys v0.36.0 h1:KVRy2GtZBrk1cBYA7MKu5bEZFxQk4NIDV6RLVcC8o0k=
+golang.org/x/sys v0.36.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/text v0.29.0 h1:1neNs90w9YzJ9BocxfsQNHKuAT4pkghyXc4nhZ6sJvk=
+golang.org/x/text v0.29.0/go.mod h1:7MhJOA9CD2qZyOKYazxdYMF85OwPdEr9jTtBpO7ydH4=
 lukechampine.com/adiantum v1.1.1 h1:4fp6gTxWCqpEbLy40ExiYDDED3oUNWx5cTqBCtPdZqA=
 lukechampine.com/adiantum v1.1.1/go.mod h1:LrAYVnTYLnUtE/yMp5bQr0HstAf060YUF8nM0B6+rUw=

gormlite/go.mod

@@ -1,12 +1,10 @@
 module github.com/ncruces/go-sqlite3/gormlite
 
-go 1.23.0
-
-toolchain go1.24.0
+go 1.24.0
 
 require (
-	github.com/ncruces/go-sqlite3 v0.26.3
-	gorm.io/gorm v1.30.0
+	github.com/ncruces/go-sqlite3 v0.29.0
+	gorm.io/gorm v1.30.5
 )
 
 require (
@@ -14,6 +12,6 @@ require (
 	github.com/jinzhu/now v1.1.5 // indirect
 	github.com/ncruces/julianday v1.0.0 // indirect
 	github.com/tetratelabs/wazero v1.9.0 // indirect
-	golang.org/x/sys v0.34.0 // indirect
-	golang.org/x/text v0.27.0 // indirect
+	golang.org/x/sys v0.36.0 // indirect
+	golang.org/x/text v0.29.0 // indirect
 )

gormlite/go.sum

@@ -2,15 +2,15 @@ github.com/jinzhu/inflection v1.0.0 h1:K317FqzuhWc8YvSVlFMCCUb36O/S9MCKRDI7QkRKD
 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 v0.26.3 h1:WFkQj4KNMhbqiBPGDrVpK74w1DzcxQu3wYpmdWAvfYM=
-github.com/ncruces/go-sqlite3 v0.26.3/go.mod h1:XFTPtFIo1DmGCh+XVP8KGn9b/o2f+z0WZuT09x2N6eo=
+github.com/ncruces/go-sqlite3 v0.29.0 h1:1tsLiagCoqZEfcHDeKsNSv5jvrY/Iu393pAnw2wLNJU=
+github.com/ncruces/go-sqlite3 v0.29.0/go.mod h1:r1hSvYKPNJ+OlUA1O3r8o9LAawzPAlqeZiIdxTBBBJ0=
 github.com/ncruces/julianday v1.0.0 h1:fH0OKwa7NWvniGQtxdJRxAgkBMolni2BjDHaWTxqt7M=
 github.com/ncruces/julianday v1.0.0/go.mod h1:Dusn2KvZrrovOMJuOt0TNXL6tB7U2E8kvza5fFc9G7g=
 github.com/tetratelabs/wazero v1.9.0 h1:IcZ56OuxrtaEz8UYNRHBrUa9bYeX9oVY93KspZZBf/I=
 github.com/tetratelabs/wazero v1.9.0/go.mod h1:TSbcXCfFP0L2FGkRPxHphadXPjo1T6W+CseNNY7EkjM=
-golang.org/x/sys v0.34.0 h1:H5Y5sJ2L2JRdyv7ROF1he/lPdvFsd0mJHFw2ThKHxLA=
-golang.org/x/sys v0.34.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
-golang.org/x/text v0.27.0 h1:4fGWRpyh641NLlecmyl4LOe6yDdfaYNrGb2zdfo4JV4=
-golang.org/x/text v0.27.0/go.mod h1:1D28KMCvyooCX9hBiosv5Tz/+YLxj0j7XhWjpSUF7CU=
-gorm.io/gorm v1.30.0 h1:qbT5aPv1UH8gI99OsRlvDToLxW5zR7FzS9acZDOZcgs=
-gorm.io/gorm v1.30.0/go.mod h1:8Z33v652h4//uMA76KjeDH8mJXPm1QNCYrMeatR0DOE=
+golang.org/x/sys v0.36.0 h1:KVRy2GtZBrk1cBYA7MKu5bEZFxQk4NIDV6RLVcC8o0k=
+golang.org/x/sys v0.36.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/text v0.29.0 h1:1neNs90w9YzJ9BocxfsQNHKuAT4pkghyXc4nhZ6sJvk=
+golang.org/x/text v0.29.0/go.mod h1:7MhJOA9CD2qZyOKYazxdYMF85OwPdEr9jTtBpO7ydH4=
+gorm.io/gorm v1.30.5 h1:dvEfYwxL+i+xgCNSGGBT1lDjCzfELK8fHZxL3Ee9X0s=
+gorm.io/gorm v1.30.5/go.mod h1:8Z33v652h4//uMA76KjeDH8mJXPm1QNCYrMeatR0DOE=

gormlite/sqlite_test.go

@@ -14,10 +14,10 @@ import (
 )
 
 func TestDialector(t *testing.T) {
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
 	// Custom connection with a custom function called "my_custom_function".
-	db, err := driver.Open(tmp, func(conn *sqlite3.Conn) error {
+	db, err := driver.Open(dsn, func(conn *sqlite3.Conn) error {
 		return conn.CreateFunction("my_custom_function", 0, sqlite3.DETERMINISTIC,
 			func(ctx sqlite3.Context, arg ...sqlite3.Value) {
 				ctx.ResultText("my-result")
@@ -36,14 +36,14 @@ func TestDialector(t *testing.T) {
 	}{
 		{
 			description:  "Default driver",
-			dialector:    Open(tmp),
+			dialector:    Open(dsn),
 			openSuccess:  true,
 			query:        "SELECT 1",
 			querySuccess: true,
 		},
 		{
 			description:  "Custom function",
-			dialector:    Open(tmp),
+			dialector:    Open(dsn),
 			openSuccess:  true,
 			query:        "SELECT my_custom_function()",
 			querySuccess: false,

gormlite/test.sh

@@ -7,7 +7,7 @@ rm -rf gorm/ tests/
 go work use -r .
 go test
 
-git clone --branch v1.30.0 --filter=blob:none https://github.com/go-gorm/gorm.git
+git clone --branch v1.30.5 --filter=blob:none https://github.com/go-gorm/gorm.git
 mv gorm/tests tests
 rm -rf gorm/
 

gormlite/tests.patch

@@ -7,13 +7,14 @@ diff --git a/tests/.gitignore b/tests/.gitignore
 diff --git a/tests/tests_test.go b/tests/tests_test.go
 --- a/tests/tests_test.go
 +++ b/tests/tests_test.go
-@@ -7,9 +7,11 @@ import (
+@@ -8,9 +8,11 @@ import (
  	"path/filepath"
  	"time"
  
 +	_ "github.com/ncruces/go-sqlite3/embed"
 +	sqlite "github.com/ncruces/go-sqlite3/gormlite"
 +
+ 	"gorm.io/driver/gaussdb"
  	"gorm.io/driver/mysql"
  	"gorm.io/driver/postgres"
 -	"gorm.io/driver/sqlite"

internal/alloc/alloc_unix.go

@@ -9,24 +9,31 @@ import (
 	"golang.org/x/sys/unix"
 )
 
-func NewMemory(_, max uint64) experimental.LinearMemory {
+func NewMemory(cap, max uint64) experimental.LinearMemory {
 	// Round up to the page size.
 	rnd := uint64(unix.Getpagesize() - 1)
-	max = (max + rnd) &^ rnd
+	res := (max + rnd) &^ rnd
 
-	if max > math.MaxInt {
-		// This ensures int(max) overflows to a negative value,
+	if res > math.MaxInt {
+		// This ensures int(res) overflows to a negative value,
 		// and unix.Mmap returns EINVAL.
-		max = math.MaxUint64
+		res = math.MaxUint64
 	}
 
-	// Reserve max bytes of address space, to ensure we won't need to move it.
+	com := res
+	prot := unix.PROT_READ | unix.PROT_WRITE
+	if cap < max { // Commit memory only if cap=max.
+		com = 0
+		prot = unix.PROT_NONE
+	}
+
+	// Reserve res bytes of address space, to ensure we won't need to move it.
 	// A protected, private, anonymous mapping should not commit memory.
-	b, err := unix.Mmap(-1, 0, int(max), unix.PROT_NONE, unix.MAP_PRIVATE|unix.MAP_ANON)
+	b, err := unix.Mmap(-1, 0, int(res), prot, unix.MAP_PRIVATE|unix.MAP_ANON)
 	if err != nil {
 		panic(err)
 	}
-	return &mmappedMemory{buf: b[:0]}
+	return &mmappedMemory{buf: b[:com]}
 }
 
 // The slice covers the entire mmapped memory:
@@ -40,9 +47,11 @@ func (m *mmappedMemory) Reallocate(size uint64) []byte {
 	com := uint64(len(m.buf))
 	res := uint64(cap(m.buf))
 	if com < size && size <= res {
-		// Round up to the page size.
+		// Grow geometrically, round up to the page size.
 		rnd := uint64(unix.Getpagesize() - 1)
-		new := (size + rnd) &^ rnd
+		new := com + com>>3
+		new = min(max(size, new), res)
+		new = (new + rnd) &^ rnd
 
 		// Commit additional memory up to new bytes.
 		err := unix.Mprotect(m.buf[com:new], unix.PROT_READ|unix.PROT_WRITE)
@@ -50,8 +59,7 @@ func (m *mmappedMemory) Reallocate(size uint64) []byte {
 			return nil
 		}
 
-		// Update committed memory.
-		m.buf = m.buf[:new]
+		m.buf = m.buf[:new] // Update committed memory.
 	}
 	// Limit returned capacity because bytes beyond
 	// len(m.buf) have not yet been committed.

internal/alloc/alloc_windows.go

@@ -9,20 +9,26 @@ import (
 	"golang.org/x/sys/windows"
 )
 
-func NewMemory(_, max uint64) experimental.LinearMemory {
+func NewMemory(cap, max uint64) experimental.LinearMemory {
 	// Round up to the page size.
 	rnd := uint64(windows.Getpagesize() - 1)
-	max = (max + rnd) &^ rnd
+	res := (max + rnd) &^ rnd
 
-	if max > math.MaxInt {
-		// This ensures uintptr(max) overflows to a large value,
+	if res > math.MaxInt {
+		// This ensures uintptr(res) overflows to a large value,
 		// and windows.VirtualAlloc returns an error.
-		max = math.MaxUint64
+		res = math.MaxUint64
 	}
 
-	// Reserve max bytes of address space, to ensure we won't need to move it.
-	// This does not commit memory.
-	r, err := windows.VirtualAlloc(0, uintptr(max), windows.MEM_RESERVE, windows.PAGE_READWRITE)
+	com := res
+	kind := windows.MEM_COMMIT
+	if cap < max { // Commit memory only if cap=max.
+		com = 0
+		kind = windows.MEM_RESERVE
+	}
+
+	// Reserve res bytes of address space, to ensure we won't need to move it.
+	r, err := windows.VirtualAlloc(0, uintptr(res), uint32(kind), windows.PAGE_READWRITE)
 	if err != nil {
 		panic(err)
 	}
@@ -30,8 +36,9 @@ func NewMemory(_, max uint64) experimental.LinearMemory {
 	mem := virtualMemory{addr: r}
 	// SliceHeader, although deprecated, avoids a go vet warning.
 	sh := (*reflect.SliceHeader)(unsafe.Pointer(&mem.buf))
-	sh.Cap = int(max)
 	sh.Data = r
+	sh.Len = int(com)
+	sh.Cap = int(res)
 	return &mem
 }
 
@@ -47,9 +54,11 @@ func (m *virtualMemory) Reallocate(size uint64) []byte {
 	com := uint64(len(m.buf))
 	res := uint64(cap(m.buf))
 	if com < size && size <= res {
-		// Round up to the page size.
+		// Grow geometrically, round up to the page size.
 		rnd := uint64(windows.Getpagesize() - 1)
-		new := (size + rnd) &^ rnd
+		new := com + com>>3
+		new = min(max(size, new), res)
+		new = (new + rnd) &^ rnd
 
 		// Commit additional memory up to new bytes.
 		_, err := windows.VirtualAlloc(m.addr, uintptr(new), windows.MEM_COMMIT, windows.PAGE_READWRITE)
@@ -57,8 +66,7 @@ func (m *virtualMemory) Reallocate(size uint64) []byte {
 			return nil
 		}
 
-		// Update committed memory.
-		m.buf = m.buf[:new]
+		m.buf = m.buf[:new] // Update committed memory.
 	}
 	// Limit returned capacity because bytes beyond
 	// len(m.buf) have not yet been committed.

internal/util/func.go

@@ -20,20 +20,6 @@ func ExportFuncVI[T0 i32](mod wazero.HostModuleBuilder, name string, fn func(con
 		Export(name)
 }
 
-type funcVII[T0, T1 i32] func(context.Context, api.Module, T0, T1)
-
-func (fn funcVII[T0, T1]) Call(ctx context.Context, mod api.Module, stack []uint64) {
-	_ = stack[1] // prevent bounds check on every slice access
-	fn(ctx, mod, T0(stack[0]), T1(stack[1]))
-}
-
-func ExportFuncVII[T0, T1 i32](mod wazero.HostModuleBuilder, name string, fn func(context.Context, api.Module, T0, T1)) {
-	mod.NewFunctionBuilder().
-		WithGoModuleFunction(funcVII[T0, T1](fn),
-			[]api.ValueType{api.ValueTypeI32, api.ValueTypeI32}, nil).
-		Export(name)
-}
-
 type funcVIII[T0, T1, T2 i32] func(context.Context, api.Module, T0, T1, T2)
 
 func (fn funcVIII[T0, T1, T2]) Call(ctx context.Context, mod api.Module, stack []uint64) {

internal/util/json.go

@@ -1,3 +1,5 @@
+//go:build !goexperiment.jsonv2
+
 package util
 
 import (

internal/util/json_v2.go

@@ -0,0 +1,52 @@
+//go:build goexperiment.jsonv2
+
+package util
+
+import (
+	"encoding/json/v2"
+	"math"
+	"strconv"
+	"time"
+	"unsafe"
+)
+
+type JSON struct{ Value any }
+
+func (j JSON) Scan(value any) error {
+	var buf []byte
+
+	switch v := value.(type) {
+	case []byte:
+		buf = v
+	case string:
+		buf = unsafe.Slice(unsafe.StringData(v), len(v))
+	case int64:
+		buf = strconv.AppendInt(nil, v, 10)
+	case float64:
+		buf = AppendNumber(nil, v)
+	case time.Time:
+		buf = append(buf, '"')
+		buf = v.AppendFormat(buf, time.RFC3339Nano)
+		buf = append(buf, '"')
+	case nil:
+		buf = []byte("null")
+	default:
+		panic(AssertErr())
+	}
+
+	return json.Unmarshal(buf, j.Value)
+}
+
+func AppendNumber(dst []byte, f float64) []byte {
+	switch {
+	case math.IsNaN(f):
+		dst = append(dst, "null"...)
+	case math.IsInf(f, 1):
+		dst = append(dst, "9.0e999"...)
+	case math.IsInf(f, -1):
+		dst = append(dst, "-9.0e999"...)
+	default:
+		return strconv.AppendFloat(dst, f, 'g', -1, 64)
+	}
+	return dst
+}

json.go

@@ -1,6 +1,13 @@
+//go:build !goexperiment.jsonv2
+
 package sqlite3
 
-import "github.com/ncruces/go-sqlite3/internal/util"
+import (
+	"encoding/json"
+	"strconv"
+
+	"github.com/ncruces/go-sqlite3/internal/util"
+)
 
 // JSON returns a value that can be used as an argument to
 // [database/sql.DB.Exec], [database/sql.Row.Scan] and similar methods to
@@ -10,3 +17,77 @@ import "github.com/ncruces/go-sqlite3/internal/util"
 func JSON(value any) any {
 	return util.JSON{Value: value}
 }
+
+// ResultJSON sets the result of the function to the JSON encoding of value.
+//
+// https://sqlite.org/c3ref/result_blob.html
+func (ctx Context) ResultJSON(value any) {
+	err := json.NewEncoder(callbackWriter(func(p []byte) (int, error) {
+		ctx.ResultRawText(p[:len(p)-1]) // remove the newline
+		return 0, nil
+	})).Encode(value)
+
+	if err != nil {
+		ctx.ResultError(err)
+		return // notest
+	}
+}
+
+// BindJSON binds the JSON encoding of value to the prepared statement.
+// The leftmost SQL parameter has an index of 1.
+//
+// https://sqlite.org/c3ref/bind_blob.html
+func (s *Stmt) BindJSON(param int, value any) error {
+	return json.NewEncoder(callbackWriter(func(p []byte) (int, error) {
+		return 0, s.BindRawText(param, p[:len(p)-1]) // remove the newline
+	})).Encode(value)
+}
+
+// ColumnJSON parses the JSON-encoded value of the result column
+// and stores it in the value pointed to by ptr.
+// The leftmost column of the result set has the index 0.
+//
+// https://sqlite.org/c3ref/column_blob.html
+func (s *Stmt) ColumnJSON(col int, ptr any) error {
+	var data []byte
+	switch s.ColumnType(col) {
+	case NULL:
+		data = []byte("null")
+	case TEXT:
+		data = s.ColumnRawText(col)
+	case BLOB:
+		data = s.ColumnRawBlob(col)
+	case INTEGER:
+		data = strconv.AppendInt(nil, s.ColumnInt64(col), 10)
+	case FLOAT:
+		data = util.AppendNumber(nil, s.ColumnFloat(col))
+	default:
+		panic(util.AssertErr())
+	}
+	return json.Unmarshal(data, ptr)
+}
+
+// JSON parses a JSON-encoded value
+// and stores the result in the value pointed to by ptr.
+func (v Value) JSON(ptr any) error {
+	var data []byte
+	switch v.Type() {
+	case NULL:
+		data = []byte("null")
+	case TEXT:
+		data = v.RawText()
+	case BLOB:
+		data = v.RawBlob()
+	case INTEGER:
+		data = strconv.AppendInt(nil, v.Int64(), 10)
+	case FLOAT:
+		data = util.AppendNumber(nil, v.Float())
+	default:
+		panic(util.AssertErr())
+	}
+	return json.Unmarshal(data, ptr)
+}
+
+type callbackWriter func(p []byte) (int, error)
+
+func (fn callbackWriter) Write(p []byte) (int, error) { return fn(p) }

json_v2.go

@@ -0,0 +1,113 @@
+//go:build goexperiment.jsonv2
+
+package sqlite3
+
+import (
+	"encoding/json/v2"
+	"strconv"
+
+	"github.com/ncruces/go-sqlite3/internal/util"
+)
+
+// JSON returns a value that can be used as an argument to
+// [database/sql.DB.Exec], [database/sql.Row.Scan] and similar methods to
+// store value as JSON, or decode JSON into value.
+// JSON should NOT be used with [Stmt.BindJSON], [Stmt.ColumnJSON],
+// [Value.JSON], or [Context.ResultJSON].
+func JSON(value any) any {
+	return util.JSON{Value: value}
+}
+
+// ResultJSON sets the result of the function to the JSON encoding of value.
+//
+// https://sqlite.org/c3ref/result_blob.html
+func (ctx Context) ResultJSON(value any) {
+	w := bytesWriter{sqlite: ctx.c.sqlite}
+	if err := json.MarshalWrite(&w, value); err != nil {
+		ctx.c.free(w.ptr)
+		ctx.ResultError(err)
+		return // notest
+	}
+	ctx.c.call("sqlite3_result_text_go",
+		stk_t(ctx.handle), stk_t(w.ptr), stk_t(len(w.buf)))
+}
+
+// BindJSON binds the JSON encoding of value to the prepared statement.
+// The leftmost SQL parameter has an index of 1.
+//
+// https://sqlite.org/c3ref/bind_blob.html
+func (s *Stmt) BindJSON(param int, value any) error {
+	w := bytesWriter{sqlite: s.c.sqlite}
+	if err := json.MarshalWrite(&w, value); err != nil {
+		s.c.free(w.ptr)
+		return err
+	}
+	rc := res_t(s.c.call("sqlite3_bind_text_go",
+		stk_t(s.handle), stk_t(param),
+		stk_t(w.ptr), stk_t(len(w.buf))))
+	return s.c.error(rc)
+}
+
+// ColumnJSON parses the JSON-encoded value of the result column
+// and stores it in the value pointed to by ptr.
+// The leftmost column of the result set has the index 0.
+//
+// https://sqlite.org/c3ref/column_blob.html
+func (s *Stmt) ColumnJSON(col int, ptr any) error {
+	var data []byte
+	switch s.ColumnType(col) {
+	case NULL:
+		data = []byte("null")
+	case TEXT:
+		data = s.ColumnRawText(col)
+	case BLOB:
+		data = s.ColumnRawBlob(col)
+	case INTEGER:
+		data = strconv.AppendInt(nil, s.ColumnInt64(col), 10)
+	case FLOAT:
+		data = util.AppendNumber(nil, s.ColumnFloat(col))
+	default:
+		panic(util.AssertErr())
+	}
+	return json.Unmarshal(data, ptr)
+}
+
+// JSON parses a JSON-encoded value
+// and stores the result in the value pointed to by ptr.
+func (v Value) JSON(ptr any) error {
+	var data []byte
+	switch v.Type() {
+	case NULL:
+		data = []byte("null")
+	case TEXT:
+		data = v.RawText()
+	case BLOB:
+		data = v.RawBlob()
+	case INTEGER:
+		data = strconv.AppendInt(nil, v.Int64(), 10)
+	case FLOAT:
+		data = util.AppendNumber(nil, v.Float())
+	default:
+		panic(util.AssertErr())
+	}
+	return json.Unmarshal(data, ptr)
+}
+
+type bytesWriter struct {
+	*sqlite
+	buf []byte
+	ptr ptr_t
+}
+
+func (b *bytesWriter) Write(p []byte) (n int, err error) {
+	if len(p) > cap(b.buf)-len(b.buf) {
+		want := int64(len(b.buf)) + int64(len(p))
+		grow := int64(cap(b.buf))
+		grow += grow >> 1
+		want = max(want, grow)
+		b.ptr = b.realloc(b.ptr, want)
+		b.buf = util.View(b.mod, b.ptr, want)[:len(b.buf)]
+	}
+	b.buf = append(b.buf, p...)
+	return len(p), nil
+}

sqlite.go

@@ -5,6 +5,7 @@ import (
 	"context"
 	"math/bits"
 	"os"
+	"strings"
 	"sync"
 	"unsafe"
 
@@ -128,11 +129,10 @@ func (sqlt *sqlite) error(rc res_t, handle ptr_t, sql ...string) error {
 		var msg, query string
 		if ptr := ptr_t(sqlt.call("sqlite3_errmsg", stk_t(handle))); ptr != 0 {
 			msg = util.ReadString(sqlt.mod, ptr, _MAX_LENGTH)
-			switch {
-			case msg == "not an error":
-				msg = ""
-			case msg == util.ErrorCodeString(uint32(rc))[len("sqlite3: "):]:
+			if msg == "not an error" {
 				msg = ""
+			} else {
+				msg = strings.TrimPrefix(msg, util.ErrorCodeString(uint32(rc))[len("sqlite3: "):])
 			}
 		}
 

sqlite3/busy_timeout.patch

@@ -2,7 +2,7 @@
 # handle, and interrupt, sqlite3_busy_timeout.
 --- sqlite3.c.orig
 +++ sqlite3.c
-@@ -184433,7 +184433,7 @@
+@@ -184474,7 +184474,7 @@
    if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
  #endif
    if( ms>0 ){

sqlite3/download.sh

@@ -3,7 +3,16 @@ set -euo pipefail
 
 cd -P -- "$(dirname -- "$0")"
 
-curl -#OL "https://sqlite.org/2025/sqlite-amalgamation-3500200.zip"
+curl -#OL "https://sqlite.org/2025/sqlite-amalgamation-3500400.zip"
+
+# Verify download.
+if hash=$(openssl dgst -sha3-256 sqlite-amalgamation-*.zip); then
+  if ! [[ $hash =~ f131b68e6ba5fb891cc13ebb5ff9555054c77294cb92d8d1268bad5dba4fa2a1 ]]; then
+    echo $hash
+    exit 1
+  fi
+fi 2> /dev/null
+
 unzip -d . sqlite-amalgamation-*.zip
 mv sqlite-amalgamation-*/sqlite3.c .
 mv sqlite-amalgamation-*/sqlite3.h .
@@ -19,30 +28,30 @@ rm -rf sqlite-amalgamation-*
 
 mkdir -p ext/
 cd ext/
-curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.2/ext/misc/anycollseq.c"
-curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.2/ext/misc/base64.c"
-curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.2/ext/misc/decimal.c"
-curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.2/ext/misc/ieee754.c"
-curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.2/ext/misc/regexp.c"
-curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.2/ext/misc/series.c"
-curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.2/ext/misc/spellfix.c"
-curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.2/ext/misc/uint.c"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.4/ext/misc/anycollseq.c"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.4/ext/misc/base64.c"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.4/ext/misc/decimal.c"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.4/ext/misc/ieee754.c"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.4/ext/misc/regexp.c"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.4/ext/misc/series.c"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.4/ext/misc/spellfix.c"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.4/ext/misc/uint.c"
 cd ~-
 
 cd ../vfs/tests/mptest/testdata/
-curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.2/mptest/config01.test"
-curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.2/mptest/config02.test"
-curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.2/mptest/crash01.test"
-curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.2/mptest/crash02.subtest"
-curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.2/mptest/multiwrite01.test"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.4/mptest/config01.test"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.4/mptest/config02.test"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.4/mptest/crash01.test"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.4/mptest/crash02.subtest"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.4/mptest/multiwrite01.test"
 cd ~-
 
 cd ../vfs/tests/mptest/wasm/
-curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.2/mptest/mptest.c"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.4/mptest/mptest.c"
 cd ~-
 
 cd ../vfs/tests/speedtest1/wasm/
-curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.2/test/speedtest1.c"
+curl -#OL "https://github.com/sqlite/sqlite/raw/version-3.50.4/test/speedtest1.c"
 cd ~-
 
 cat *.patch | patch -p0 --no-backup-if-mismatch

sqlite3/libc/build.sh

@@ -22,7 +22,8 @@ EOF
 	-mmutable-globals -mnontrapping-fptoint \
 	-msimd128 -mbulk-memory -msign-ext \
 	-mreference-types -mmultivalue \
-	-fno-stack-protector -fno-stack-clash-protection \
+	-mno-extended-const \
+	-fno-stack-protector \
 	-Wl,-z,stack-size=4096 \
 	-Wl,--stack-first \
 	-Wl,--import-undefined \
@@ -42,10 +43,11 @@ EOF
 	-Wl,--export=qsort
 
 "$BINARYEN/wasm-ctor-eval" -g -c _initialize libc.wasm -o libc.tmp
-"$BINARYEN/wasm-opt" -g --strip --strip-producers -c -O3 \
-	libc.tmp -o libc.wasm \
+"$BINARYEN/wasm-opt" -g libc.tmp -o libc.wasm \
+	--low-memory-unused --generate-global-effects --converge -O3 \
 	--enable-mutable-globals --enable-nontrapping-float-to-int \
 	--enable-simd --enable-bulk-memory --enable-sign-ext \
-	--enable-reference-types --enable-multivalue
+	--enable-reference-types --enable-multivalue \
+	--strip --strip-debug --strip-producers
 
 "$BINARYEN/wasm-dis" -o libc.wat libc.wasm

sqlite3/libc/libc_test.go

@@ -8,7 +8,6 @@ import (
 	"os"
 	"strings"
 	"testing"
-	"unicode/utf8"
 
 	"github.com/tetratelabs/wazero"
 	"github.com/tetratelabs/wazero/api"
@@ -76,8 +75,7 @@ func Benchmark_memset(b *testing.B) {
 	clear(memory)
 
 	b.SetBytes(size)
-	b.ResetTimer()
-	for range b.N {
+	for b.Loop() {
 		call(memset, ptr1, 3, size)
 	}
 }
@@ -87,8 +85,7 @@ func Benchmark_memcpy(b *testing.B) {
 	fill(memory[ptr2:ptr2+size], 5)
 
 	b.SetBytes(size)
-	b.ResetTimer()
-	for range b.N {
+	for b.Loop() {
 		call(memcpy, ptr1, ptr2, size)
 	}
 }
@@ -98,8 +95,7 @@ func Benchmark_strlen(b *testing.B) {
 	fill(memory[ptr1:ptr1+size-1], 5)
 
 	b.SetBytes(size)
-	b.ResetTimer()
-	for range b.N {
+	for b.Loop() {
 		call(strlen, ptr1)
 	}
 }
@@ -110,8 +106,7 @@ func Benchmark_memchr(b *testing.B) {
 	fill(memory[ptr1+size/2:ptr1+size], 5)
 
 	b.SetBytes(size/2 + 1)
-	b.ResetTimer()
-	for range b.N {
+	for b.Loop() {
 		call(memchr, ptr1, 5, size)
 	}
 }
@@ -122,8 +117,7 @@ func Benchmark_strchr(b *testing.B) {
 	fill(memory[ptr1+size/2:ptr1+size-1], 5)
 
 	b.SetBytes(size/2 + 1)
-	b.ResetTimer()
-	for range b.N {
+	for b.Loop() {
 		call(strchr, ptr1, 5)
 	}
 }
@@ -134,8 +128,7 @@ func Benchmark_strrchr(b *testing.B) {
 	fill(memory[ptr1+size/2:ptr1+size-1], 7)
 
 	b.SetBytes(size/2 + 1)
-	b.ResetTimer()
-	for range b.N {
+	for b.Loop() {
 		call(strrchr, ptr1, 5)
 	}
 }
@@ -147,8 +140,7 @@ func Benchmark_memcmp(b *testing.B) {
 	fill(memory[ptr2+size/2:ptr2+size], 5)
 
 	b.SetBytes(size/2 + 1)
-	b.ResetTimer()
-	for range b.N {
+	for b.Loop() {
 		call(memcmp, ptr1, ptr2, size)
 	}
 }
@@ -163,8 +155,7 @@ func Benchmark_strspn(b *testing.B) {
 	memory[ptr2+3] = 9
 
 	b.SetBytes(size)
-	b.ResetTimer()
-	for range b.N {
+	for b.Loop() {
 		call(strspn, ptr1, ptr2)
 	}
 }
@@ -177,8 +168,7 @@ func Benchmark_strcspn(b *testing.B) {
 	memory[ptr2+1] = 9
 
 	b.SetBytes(size)
-	b.ResetTimer()
-	for range b.N {
+	for b.Loop() {
 		call(strcspn, ptr1, ptr2)
 	}
 }
@@ -750,15 +740,7 @@ func Fuzz_strspn(f *testing.F) {
 
 		s = term(s)
 		chars = term(chars)
-		want := strings.IndexFunc(s, func(r rune) bool {
-			if uint32(r) >= utf8.RuneSelf {
-				t.Skip()
-			}
-			return strings.IndexByte(chars, byte(r)) < 0
-		})
-		if want < 0 {
-			want = len(s)
-		}
+		want := indexNotByte(s, chars)
 
 		if uint32(got) != uint32(want) {
 			t.Errorf("strspn(%v, %v) = %d, want %d",
@@ -778,11 +760,6 @@ func Fuzz_strcspn(f *testing.F) {
 		if len(s) > 128 || len(chars) > 128 {
 			t.SkipNow()
 		}
-		if strings.ContainsFunc(chars, func(r rune) bool {
-			return uint32(r) >= utf8.RuneSelf
-		}) {
-			t.SkipNow()
-		}
 		copy(memory[ptr1:], s)
 		copy(memory[ptr2:], chars)
 		memory[ptr1+len(s)] = 0
@@ -792,10 +769,7 @@ func Fuzz_strcspn(f *testing.F) {
 
 		s = term(s)
 		chars = term(chars)
-		want := strings.IndexAny(s, chars)
-		if want < 0 {
-			want = len(s)
-		}
+		want := indexAnyByte(s, chars)
 
 		if uint32(got) != uint32(want) {
 			t.Errorf("strcspn(%q, %q) = %d, want %d",
@@ -838,3 +812,21 @@ func term1[T interface{ []byte | string }](s T) T {
 	}
 	return s
 }
+
+func indexNotByte(s, chars string) int {
+	for i, c := range []byte(s) {
+		if strings.IndexByte(chars, c) < 0 {
+			return i
+		}
+	}
+	return len(s)
+}
+
+func indexAnyByte(s, chars string) int {
+	for i, c := range []byte(s) {
+		if strings.IndexByte(chars, c) >= 0 {
+			return i
+		}
+	}
+	return len(s)
+}

sqlite3/libc/string.h

@@ -242,17 +242,21 @@ char *strrchr(const char *s, int c) {
 // SIMDized check which bytes are in a set (Geoff Langdale)
 // http://0x80.pl/notesen/2018-10-18-simd-byte-lookup.html
 
+// This is the same algorithm as truffle from Hyperscan:
+// https://github.com/intel/hyperscan/blob/v5.4.2/src/nfa/truffle.c#L64-L81
+// https://github.com/intel/hyperscan/blob/v5.4.2/src/nfa/trufflecompile.cpp
+
 typedef struct {
   __u8x16 lo;
   __u8x16 hi;
 } __wasm_v128_bitmap256_t;
 
 __attribute__((always_inline))
-static void __wasm_v128_setbit(__wasm_v128_bitmap256_t *bitmap, int i) {
-  uint8_t hi_nibble = (uint8_t)i >> 4;
-  uint8_t lo_nibble = (uint8_t)i & 0xf;
-  bitmap->lo[lo_nibble] |= (uint8_t)((uint32_t)1 << (hi_nibble - 0));
-  bitmap->hi[lo_nibble] |= (uint8_t)((uint32_t)1 << (hi_nibble - 8));
+static void __wasm_v128_setbit(__wasm_v128_bitmap256_t *bitmap, uint8_t i) {
+  uint8_t hi_nibble = i >> 4;
+  uint8_t lo_nibble = i & 0xf;
+  bitmap->lo[lo_nibble] |= (uint8_t)(1u << (hi_nibble - 0));
+  bitmap->hi[lo_nibble] |= (uint8_t)(1u << (hi_nibble - 8));
 }
 
 #ifndef __wasm_relaxed_simd__
@@ -264,18 +268,17 @@ static void __wasm_v128_setbit(__wasm_v128_bitmap256_t *bitmap, int i) {
 __attribute__((always_inline))
 static v128_t __wasm_v128_chkbits(__wasm_v128_bitmap256_t bitmap, v128_t v) {
   v128_t hi_nibbles = wasm_u8x16_shr(v, 4);
-  v128_t bitmask_lookup = wasm_u8x16_const(1, 2, 4, 8, 16, 32, 64, 128,  //
-                                           1, 2, 4, 8, 16, 32, 64, 128);
+  v128_t bitmask_lookup = wasm_u64x2_const_splat(0x8040201008040201);
   v128_t bitmask = wasm_i8x16_relaxed_swizzle(bitmask_lookup, hi_nibbles);
 
   v128_t indices_0_7 = v & wasm_u8x16_const_splat(0x8f);
   v128_t indices_8_15 = indices_0_7 ^ wasm_u8x16_const_splat(0x80);
 
-  v128_t row_0_7 = wasm_i8x16_swizzle(bitmap.lo, indices_0_7);
-  v128_t row_8_15 = wasm_i8x16_swizzle(bitmap.hi, indices_8_15);
+  v128_t row_0_7 = wasm_i8x16_swizzle((v128_t)bitmap.lo, indices_0_7);
+  v128_t row_8_15 = wasm_i8x16_swizzle((v128_t)bitmap.hi, indices_8_15);
 
   v128_t bitsets = row_0_7 | row_8_15;
-  return wasm_i8x16_eq(bitsets & bitmask, bitmask);
+  return bitsets & bitmask;
 }
 
 #undef wasm_i8x16_relaxed_swizzle
@@ -317,17 +320,18 @@ size_t strspn(const char *s, const char *c) {
 
   for (; *c; c++) {
     // Terminator IS NOT on the bitmap.
-    __wasm_v128_setbit(&bitmap, *c);
+    __wasm_v128_setbit(&bitmap, (uint8_t)*c);
   }
 
   for (;;) {
     v128_t v = *(v128_t *)addr;
-    v128_t cmp = __wasm_v128_chkbits(bitmap, v);
+    v128_t found = __wasm_v128_chkbits(bitmap, v);
     // Bitmask is slow on AArch64, all_true is much faster.
-    if (!wasm_i8x16_all_true(cmp)) {
+    if (!wasm_i8x16_all_true(found)) {
+      v128_t cmp = wasm_i8x16_eq(found, (v128_t){});
       // Clear the bits corresponding to align (little-endian)
       // so we can count trailing zeros.
-      int mask = (uint16_t)~wasm_i8x16_bitmask(cmp) >> align << align;
+      int mask = wasm_i8x16_bitmask(cmp) >> align << align;
       // At least one bit will be set, unless align cleared them.
       // Knowing this helps the compiler if it unrolls the loop.
       __builtin_assume(mask || align);
@@ -356,17 +360,18 @@ size_t strcspn(const char *s, const char *c) {
 
   do {
     // Terminator IS on the bitmap.
-    __wasm_v128_setbit(&bitmap, *c);
+    __wasm_v128_setbit(&bitmap, (uint8_t)*c);
   } while (*c++);
 
   for (;;) {
     v128_t v = *(v128_t *)addr;
-    v128_t cmp = __wasm_v128_chkbits(bitmap, v);
+    v128_t found = __wasm_v128_chkbits(bitmap, v);
     // Bitmask is slow on AArch64, any_true is much faster.
-    if (wasm_v128_any_true(cmp)) {
+    if (wasm_v128_any_true(found)) {
+      v128_t cmp = wasm_i8x16_eq(found, (v128_t){});
       // Clear the bits corresponding to align (little-endian)
       // so we can count trailing zeros.
-      int mask = wasm_i8x16_bitmask(cmp) >> align << align;
+      int mask = (uint16_t)~wasm_i8x16_bitmask(cmp) >> align << align;
       // At least one bit will be set, unless align cleared them.
       // Knowing this helps the compiler if it unrolls the loop.
       __builtin_assume(mask || align);

sqlite3/tools.sh

@@ -26,8 +26,8 @@ elif [[ "$OSTYPE" == "darwin"* ]]; then
   fi
 fi
 
-WASI_SDK="https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-25/wasi-sdk-25.0-$WASI_SDK.tar.gz"
-BINARYEN="https://github.com/WebAssembly/binaryen/releases/download/version_123/binaryen-version_123-$BINARYEN.tar.gz"
+WASI_SDK="https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-27/wasi-sdk-27.0-$WASI_SDK.tar.gz"
+BINARYEN="https://github.com/WebAssembly/binaryen/releases/download/version_124/binaryen-version_124-$BINARYEN.tar.gz"
 
 # Download tools
 mkdir -p "$ROOT/tools"

sqlite3/vfs_find.patch

@@ -1,7 +1,7 @@
 # Remove VFS registration. Go handles it.
 --- sqlite3.c.orig
 +++ sqlite3.c
-@@ -26883,7 +26883,7 @@
+@@ -26884,7 +26884,7 @@
    sqlite3_free(p);
    return sqlite3_os_init();
  }
@@ -10,7 +10,7 @@
  /*
  ** The list of all registered VFS implementations.
  */
-@@ -26980,7 +26980,7 @@
+@@ -26981,7 +26981,7 @@
    sqlite3_mutex_leave(mutex);
    return SQLITE_OK;
  }

stmt.go

@@ -1,9 +1,7 @@
 package sqlite3
 
 import (
-	"encoding/json"
 	"math"
-	"strconv"
 	"time"
 
 	"github.com/ncruces/go-sqlite3/internal/util"
@@ -362,16 +360,6 @@ func (s *Stmt) BindPointer(param int, ptr any) error {
 	return s.c.error(rc)
 }
 
-// BindJSON binds the JSON encoding of value to the prepared statement.
-// The leftmost SQL parameter has an index of 1.
-//
-// https://sqlite.org/c3ref/bind_blob.html
-func (s *Stmt) BindJSON(param int, value any) error {
-	return json.NewEncoder(callbackWriter(func(p []byte) (int, error) {
-		return 0, s.BindRawText(param, p[:len(p)-1]) // remove the newline
-	})).Encode(value)
-}
-
 // BindValue binds a copy of value to the prepared statement.
 // The leftmost SQL parameter has an index of 1.
 //
@@ -598,30 +586,6 @@ func (s *Stmt) columnRawBytes(col int, ptr ptr_t, nul int32) []byte {
 	return util.View(s.c.mod, ptr, int64(n+nul))[:n]
 }
 
-// ColumnJSON parses the JSON-encoded value of the result column
-// and stores it in the value pointed to by ptr.
-// The leftmost column of the result set has the index 0.
-//
-// https://sqlite.org/c3ref/column_blob.html
-func (s *Stmt) ColumnJSON(col int, ptr any) error {
-	var data []byte
-	switch s.ColumnType(col) {
-	case NULL:
-		data = []byte("null")
-	case TEXT:
-		data = s.ColumnRawText(col)
-	case BLOB:
-		data = s.ColumnRawBlob(col)
-	case INTEGER:
-		data = strconv.AppendInt(nil, s.ColumnInt64(col), 10)
-	case FLOAT:
-		data = util.AppendNumber(nil, s.ColumnFloat(col))
-	default:
-		panic(util.AssertErr())
-	}
-	return json.Unmarshal(data, ptr)
-}
-
 // ColumnValue returns the unprotected value of the result column.
 // The leftmost column of the result set has the index 0.
 //
@@ -748,7 +712,3 @@ func (s *Stmt) columns(count int64) ([]byte, ptr_t, error) {
 
 	return util.View(s.c.mod, typePtr, count), dataPtr, nil
 }
-
-type callbackWriter func(p []byte) (int, error)
-
-func (fn callbackWriter) Write(p []byte) (int, error) { return fn(p) }

tests/blob_test.go

@@ -45,10 +45,7 @@ func TestBlob(t *testing.T) {
 	}
 
 	var data [1280]byte
-	_, err = rand.Read(data[:])
-	if err != nil {
-		t.Fatal(err)
-	}
+	rand.Read(data[:])
 
 	_, err = blob.Write(data[:size/2])
 	if err != nil {

tests/bradfitz/sql_test.go

@@ -35,7 +35,7 @@ type params struct {
 	*sql.DB
 }
 
-func (t params) mustExec(sql string, args ...interface{}) sql.Result {
+func (t params) mustExec(sql string, args ...any) sql.Result {
 	res, err := t.DB.Exec(sql, args...)
 	if err != nil {
 		t.Fatalf("Error running %q: %v", sql, err)

tests/config_test.go

@@ -388,11 +388,11 @@ func TestConn_Trace(t *testing.T) {
 
 func TestConn_AutoVacuumPages(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t, url.Values{
+	dsn := memdb.TestDB(t, url.Values{
 		"_pragma": {"auto_vacuum(full)"},
 	})
 
-	db, err := sqlite3.Open(tmp)
+	db, err := sqlite3.Open(dsn)
 	if err != nil {
 		t.Fatal(err)
 	}

tests/conn_test.go

@@ -12,7 +12,7 @@ import (
 	"github.com/ncruces/go-sqlite3"
 	_ "github.com/ncruces/go-sqlite3/embed"
 	_ "github.com/ncruces/go-sqlite3/internal/testcfg"
-	_ "github.com/ncruces/go-sqlite3/vfs/memdb"
+	"github.com/ncruces/go-sqlite3/vfs/memdb"
 )
 
 func TestConn_Open_dir(t *testing.T) {
@@ -112,6 +112,48 @@ func TestConn_Close_BUSY(t *testing.T) {
 	}
 }
 
+func TestConn_BusyHandler(t *testing.T) {
+	t.Parallel()
+
+	dsn := memdb.TestDB(t)
+
+	db1, err := sqlite3.Open(dsn)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db1.Close()
+
+	db2, err := sqlite3.Open(dsn)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db2.Close()
+
+	var called bool
+	err = db2.BusyHandler(func(ctx context.Context, count int) (retry bool) {
+		called = true
+		return count < 1
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	tx, err := db1.BeginExclusive()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer tx.End(&err)
+
+	_, err = db2.BeginExclusive()
+	if !errors.Is(err, sqlite3.BUSY) {
+		t.Errorf("got %v, want sqlite3.BUSY", err)
+	}
+
+	if !called {
+		t.Error("busy handler not called")
+	}
+}
+
 func TestConn_SetInterrupt(t *testing.T) {
 	t.Parallel()
 
@@ -121,7 +163,7 @@ func TestConn_SetInterrupt(t *testing.T) {
 	}
 	defer db.Close()
 
-	ctx, cancel := context.WithCancel(context.Background())
+	ctx, cancel := context.WithCancel(t.Context())
 	db.SetInterrupt(ctx)
 
 	// Interrupt doesn't interrupt this.
@@ -160,9 +202,7 @@ func TestConn_SetInterrupt(t *testing.T) {
 		t.Errorf("got %v, want sqlite3.INTERRUPT", err)
 	}
 
-	ctx, cancel = context.WithCancel(context.Background())
-	defer cancel()
-	db.SetInterrupt(ctx)
+	db.SetInterrupt(t.Context())
 
 	// Interrupting can be cleared.
 	err = db.Exec(`SELECT 1`)
@@ -170,9 +210,8 @@ func TestConn_SetInterrupt(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	db.SetInterrupt(ctx)
-	if got := db.GetInterrupt(); got != ctx {
-		t.Errorf("got %v, want %v", got, ctx)
+	if got := db.GetInterrupt(); got != t.Context() {
+		t.Errorf("got %v, want %v", got, t.Context())
 	}
 }
 

tests/driver_test.go

@@ -1,7 +1,6 @@
 package tests
 
 import (
-	"context"
 	"testing"
 
 	"github.com/ncruces/go-sqlite3"
@@ -13,12 +12,9 @@ import (
 
 func TestDriver(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	db, err := driver.Open(tmp, nil, func(c *sqlite3.Conn) error {
+	db, err := driver.Open(dsn, nil, func(c *sqlite3.Conn) error {
 		return c.Exec(`PRAGMA optimize`)
 	})
 	if err != nil {
@@ -26,13 +22,13 @@ func TestDriver(t *testing.T) {
 	}
 	defer db.Close()
 
-	conn, err := db.Conn(ctx)
+	conn, err := db.Conn(t.Context())
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer conn.Close()
 
-	res, err := conn.ExecContext(ctx,
+	res, err := conn.ExecContext(t.Context(),
 		`CREATE TABLE users (id INTEGER PRIMARY KEY NOT NULL, name VARCHAR(10))`)
 	if err != nil {
 		t.Fatal(err)
@@ -52,7 +48,7 @@ func TestDriver(t *testing.T) {
 		t.Errorf("got %d want 0", changes)
 	}
 
-	res, err = conn.ExecContext(ctx,
+	res, err = conn.ExecContext(t.Context(),
 		`INSERT INTO users (id, name) VALUES (0, 'go'), (1, 'zig'), (2, 'whatever')`)
 	if err != nil {
 		t.Fatal(err)
@@ -65,7 +61,7 @@ func TestDriver(t *testing.T) {
 		t.Errorf("got %d want 3", changes)
 	}
 
-	stmt, err := conn.PrepareContext(context.Background(),
+	stmt, err := conn.PrepareContext(t.Context(),
 		`SELECT id, name FROM users`)
 	if err != nil {
 		t.Fatal(err)

tests/json_test.go

@@ -1,7 +1,6 @@
 package tests
 
 import (
-	"context"
 	"encoding/json"
 	"math"
 	"testing"
@@ -17,31 +16,28 @@ import (
 
 func TestJSON(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	db, err := driver.Open(tmp)
+	db, err := driver.Open(dsn)
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer db.Close()
 
-	conn, err := db.Conn(ctx)
+	conn, err := db.Conn(t.Context())
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer conn.Close()
 
-	_, err = conn.ExecContext(ctx, `CREATE TABLE test (col)`)
+	_, err = conn.ExecContext(t.Context(), `CREATE TABLE test (col)`)
 	if err != nil {
 		t.Fatal(err)
 	}
 
 	reference := time.Date(2013, 10, 7, 4, 23, 19, 120_000_000, time.FixedZone("", -4*3600))
 
-	_, err = conn.ExecContext(ctx,
+	_, err = conn.ExecContext(t.Context(),
 		`INSERT INTO test (col) VALUES (?), (?), (?), (?)`,
 		nil, 1, math.Pi, reference,
 	)
@@ -49,7 +45,7 @@ func TestJSON(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	_, err = conn.ExecContext(ctx,
+	_, err = conn.ExecContext(t.Context(),
 		`INSERT INTO test (col) VALUES (?), (?), (?), (?)`,
 		sqlite3.JSON(math.Pi), sqlite3.JSON(false),
 		julianday.Format(reference), sqlite3.JSON([]string{}))
@@ -57,7 +53,7 @@ func TestJSON(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	rows, err := conn.QueryContext(ctx, "SELECT * FROM test")
+	rows, err := conn.QueryContext(t.Context(), "SELECT * FROM test")
 	if err != nil {
 		t.Fatal(err)
 	}

tests/parallel/parallel_test.go

@@ -18,6 +18,7 @@ import (
 	"github.com/ncruces/go-sqlite3/vfs"
 	_ "github.com/ncruces/go-sqlite3/vfs/adiantum"
 	"github.com/ncruces/go-sqlite3/vfs/memdb"
+	"github.com/ncruces/go-sqlite3/vfs/mvcc"
 	_ "github.com/ncruces/go-sqlite3/vfs/xts"
 )
 
@@ -98,6 +99,22 @@ func Test_memdb(t *testing.T) {
 	testIntegrity(t, name)
 }
 
+func Test_mvcc(t *testing.T) {
+	var iter int
+	if testing.Short() {
+		iter = 1000
+	} else {
+		iter = 5000
+	}
+
+	name := mvcc.TestDB(t, mvcc.Snapshot{}, url.Values{
+		"_pragma": {"busy_timeout(10000)"},
+	})
+	createDB(t, name)
+	testParallel(t, name, iter)
+	testIntegrity(t, name)
+}
+
 func Test_adiantum(t *testing.T) {
 	if !vfs.SupportsFileLocking {
 		t.Skip("skipping without locks")
@@ -312,6 +329,16 @@ func Benchmark_memdb(b *testing.B) {
 	testParallel(b, name, b.N)
 }
 
+func Benchmark_mvcc(b *testing.B) {
+	name := mvcc.TestDB(b, mvcc.Snapshot{}, url.Values{
+		"_pragma": {"busy_timeout(10000)"},
+	})
+	createDB(b, name)
+
+	b.ResetTimer()
+	testParallel(b, name, b.N)
+}
+
 func createDB(t testing.TB, name string) {
 	db, err := sqlite3.Open(name)
 	if err != nil {

tests/stmt_test.go

@@ -496,7 +496,7 @@ func TestStmt(t *testing.T) {
 		if got := stmt.ColumnBlob(0, nil); string(got) != "true" {
 			t.Errorf("got %q, want true", got)
 		}
-		var got any = 1
+		var got any
 		if err := stmt.ColumnJSON(0, &got); err != nil {
 			t.Error(err)
 		} else if got != true {

tests/time_test.go

@@ -1,7 +1,6 @@
 package tests
 
 import (
-	"context"
 	"fmt"
 	"reflect"
 	"testing"
@@ -134,37 +133,36 @@ func TestTimeFormat_Decode(t *testing.T) {
 
 func TestTimeFormat_Scanner(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	db, err := driver.Open(tmp)
+	db, err := driver.Open(dsn)
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer db.Close()
 
-	conn, err := db.Conn(ctx)
+	conn, err := db.Conn(t.Context())
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer conn.Close()
 
-	_, err = conn.ExecContext(ctx, `CREATE TABLE test (col)`)
+	_, err = conn.ExecContext(t.Context(), `CREATE TABLE test (col)`)
 	if err != nil {
 		t.Fatal(err)
 	}
 
 	reference := time.Date(2013, 10, 7, 4, 23, 19, 120_000_000, time.FixedZone("", -4*3600))
 
-	_, err = conn.ExecContext(ctx, `INSERT INTO test VALUES (?)`, sqlite3.TimeFormat7TZ.Encode(reference))
+	_, err = conn.ExecContext(t.Context(), `INSERT INTO test VALUES (?)`,
+		sqlite3.TimeFormat7TZ.Encode(reference))
 	if err != nil {
 		t.Fatal(err)
 	}
 
 	var got time.Time
-	err = conn.QueryRowContext(ctx, "SELECT * FROM test").Scan(sqlite3.TimeFormatAuto.Scanner(&got))
+	err = conn.QueryRowContext(t.Context(), "SELECT * FROM test").
+		Scan(sqlite3.TimeFormatAuto.Scanner(&got))
 	if err != nil {
 		t.Fatal(err)
 	}

tests/txn_test.go

@@ -170,7 +170,7 @@ func TestConn_Transaction_interrupt(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	ctx, cancel := context.WithCancel(context.Background())
+	ctx, cancel := context.WithCancel(t.Context())
 	db.SetInterrupt(ctx)
 
 	tx, err = db.BeginExclusive()
@@ -203,7 +203,7 @@ func TestConn_Transaction_interrupt(t *testing.T) {
 		t.Errorf("got %v, want sqlite3.INTERRUPT", err)
 	}
 
-	db.SetInterrupt(context.Background())
+	db.SetInterrupt(t.Context())
 	stmt, _, err := db.Prepare(`SELECT count(*) FROM test`)
 	if err != nil {
 		t.Fatal(err)
@@ -226,7 +226,7 @@ func TestConn_Transaction_interrupted(t *testing.T) {
 	}
 	defer db.Close()
 
-	ctx, cancel := context.WithCancel(context.Background())
+	ctx, cancel := context.WithCancel(t.Context())
 	db.SetInterrupt(ctx)
 	cancel()
 
@@ -246,15 +246,15 @@ func TestConn_Transaction_interrupted(t *testing.T) {
 
 func TestConn_Transaction_busy(t *testing.T) {
 	t.Parallel()
-	tmp := memdb.TestDB(t)
+	dsn := memdb.TestDB(t)
 
-	db1, err := sqlite3.Open(tmp)
+	db1, err := sqlite3.Open(dsn)
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer db1.Close()
 
-	db2, err := sqlite3.Open(tmp + "&_pragma=busy_timeout(10000)")
+	db2, err := sqlite3.Open(dsn + "&_pragma=busy_timeout(10000)")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -274,7 +274,7 @@ func TestConn_Transaction_busy(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	ctx, cancel := context.WithCancel(context.Background())
+	ctx, cancel := context.WithCancel(t.Context())
 	db2.SetInterrupt(ctx)
 	go cancel()
 
@@ -493,7 +493,7 @@ func TestConn_Savepoint_interrupt(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	ctx, cancel := context.WithCancel(context.Background())
+	ctx, cancel := context.WithCancel(t.Context())
 	db.SetInterrupt(ctx)
 
 	savept1 := db.Savepoint()
@@ -530,7 +530,7 @@ func TestConn_Savepoint_interrupt(t *testing.T) {
 		t.Errorf("got %v, want sqlite3.INTERRUPT", err)
 	}
 
-	db.SetInterrupt(context.Background())
+	db.SetInterrupt(t.Context())
 	stmt, _, err := db.Prepare(`SELECT count(*) FROM test`)
 	if err != nil {
 		t.Fatal(err)

time.go

@@ -94,7 +94,7 @@ func (f TimeFormat) Encode(t time.Time) any {
 	case TimeFormatUnix:
 		return t.Unix()
 	case TimeFormatUnixFrac:
-		return float64(t.Unix()) + float64(t.Nanosecond())*1e-9
+		return math.FMA(1e-9, float64(t.Nanosecond()), float64(t.Unix()))
 	case TimeFormatUnixMilli:
 		return t.UnixMilli()
 	case TimeFormatUnixMicro:

util/ioutil/seek.go

@@ -49,7 +49,7 @@ func (s *SeekingReaderAt) Size() (int64, error) {
 	return s.r.Seek(0, io.SeekEnd)
 }
 
-// ReadAt implements [io.Closer].
+// Close implements [io.Closer].
 func (s *SeekingReaderAt) Close() error {
 	s.l.Lock()
 	defer s.l.Unlock()

util/osutil/osfs.go

@@ -23,7 +23,7 @@ func (FS) Open(name string) (fs.File, error) {
 	return os.OpenFile(name, os.O_RDONLY, 0)
 }
 
-// ReadFileFS implements [fs.StatFS].
+// Stat implements [fs.StatFS].
 func (FS) Stat(name string) (fs.FileInfo, error) {
 	return os.Stat(name)
 }

util/sql3util/wasm/build.sh

@@ -17,14 +17,16 @@ trap 'rm -f sql3parse_table.tmp' EXIT
 	-mmutable-globals -mnontrapping-fptoint \
 	-msimd128 -mbulk-memory -msign-ext \
 	-mreference-types -mmultivalue \
-	-fno-stack-protector -fno-stack-clash-protection \
+	-mno-extended-const \
+	-fno-stack-protector \
 	-Wl,--stack-first \
 	-Wl,--import-undefined \
 	-Wl,--export=sql3parse_table
 
 "$BINARYEN/wasm-ctor-eval" -c _initialize sql3parse_table.wasm -o sql3parse_table.tmp
-"$BINARYEN/wasm-opt" --strip --strip-debug --strip-producers -c -Oz \
-	sql3parse_table.tmp -o sql3parse_table.wasm --low-memory-unused \
+"$BINARYEN/wasm-opt" sql3parse_table.tmp -o sql3parse_table.wasm \
+	--low-memory-unused --gufa --generate-global-effects --converge -Oz \
 	--enable-mutable-globals --enable-nontrapping-float-to-int \
 	--enable-simd --enable-bulk-memory --enable-sign-ext \
-	--enable-reference-types --enable-multivalue
+	--enable-reference-types --enable-multivalue \
+	--strip --strip-debug --strip-producers

util/vfsutil/slice.go

@@ -0,0 +1,102 @@
+package vfsutil
+
+import (
+	"io"
+
+	"github.com/ncruces/go-sqlite3"
+	"github.com/ncruces/go-sqlite3/vfs"
+)
+
+// SliceFile implements [vfs.File] with a byte slice.
+// It is suitable for temporary files (such as [vfs.OPEN_TEMP_JOURNAL]),
+// but not concurrency safe.
+type SliceFile []byte
+
+var (
+	// Ensure these interfaces are implemented:
+	_ vfs.FileSizeHint = &SliceFile{}
+)
+
+// ReadAt implements [io.ReaderAt].
+func (f *SliceFile) ReadAt(b []byte, off int64) (n int, err error) {
+	if d := *f; off < int64(len(d)) {
+		n = copy(b, d[off:])
+	}
+	if n < len(b) {
+		err = io.EOF
+	}
+	return
+}
+
+// WriteAt implements [io.WriterAt].
+func (f *SliceFile) WriteAt(b []byte, off int64) (n int, err error) {
+	d := *f
+	if off > int64(len(d)) {
+		d = append(d, make([]byte, off-int64(len(d)))...)
+	}
+	d = append(d[:off], b...)
+	if len(d) > len(*f) {
+		*f = d
+	}
+	return len(b), nil
+}
+
+// Size implements [vfs.File].
+func (f *SliceFile) Size() (int64, error) {
+	return int64(len(*f)), nil
+}
+
+// Truncate implements [vfs.File].
+func (f *SliceFile) Truncate(size int64) error {
+	if d := *f; size < int64(len(d)) {
+		*f = d[:size]
+	}
+	return nil
+}
+
+// SizeHint implements [vfs.FileSizeHint].
+func (f *SliceFile) SizeHint(size int64) error {
+	if d := *f; size > int64(len(d)) {
+		*f = append(d, make([]byte, size-int64(len(d)))...)
+	}
+	return nil
+}
+
+// Close implements [io.Closer].
+func (*SliceFile) Close() error { return nil }
+
+// Sync implements [vfs.File].
+func (*SliceFile) Sync(flags vfs.SyncFlag) error { return nil }
+
+// Lock implements [vfs.File].
+func (*SliceFile) Lock(lock vfs.LockLevel) error {
+	// notest // not concurrency safe
+	return sqlite3.IOERR_LOCK
+}
+
+// Unlock implements [vfs.File].
+func (*SliceFile) Unlock(lock vfs.LockLevel) error {
+	// notest // not concurrency safe
+	return sqlite3.IOERR_UNLOCK
+}
+
+// CheckReservedLock implements [vfs.File].
+func (*SliceFile) CheckReservedLock() (bool, error) {
+	// notest // not concurrency safe
+	return false, sqlite3.IOERR_CHECKRESERVEDLOCK
+}
+
+// SectorSize implements [vfs.File].
+func (*SliceFile) SectorSize() int {
+	// notest // safe default
+	return 0
+}
+
+// DeviceCharacteristics implements [vfs.File].
+func (*SliceFile) DeviceCharacteristics() vfs.DeviceCharacteristic {
+	return vfs.IOCAP_ATOMIC |
+		vfs.IOCAP_SEQUENTIAL |
+		vfs.IOCAP_SAFE_APPEND |
+		vfs.IOCAP_POWERSAFE_OVERWRITE |
+		vfs.IOCAP_SUBPAGE_READ
+}

util/vfsutil/wrap.go

@@ -22,6 +22,14 @@ func UnwrapFile[T vfs.File](f vfs.File) (_ T, _ bool) {
 	}
 }
 
+// WrapOpen helps wrap [vfs.VFS].
+func WrapOpen(f vfs.VFS, name string, flags vfs.OpenFlag) (file vfs.File, _ vfs.OpenFlag, err error) {
+	if f, ok := f.(vfs.VFSFilename); name == "" && ok {
+		return f.OpenFilename(nil, flags)
+	}
+	return f.Open(name, flags)
+}
+
 // WrapOpenFilename helps wrap [vfs.VFSFilename].
 func WrapOpenFilename(f vfs.VFS, name *vfs.Filename, flags vfs.OpenFlag) (file vfs.File, _ vfs.OpenFlag, err error) {
 	if f, ok := f.(vfs.VFSFilename); ok {

util/vfsutil/wrap_test.go

@@ -0,0 +1,330 @@
+// Package vfsutil implements virtual filesystem utilities.
+package vfsutil
+
+import (
+	"testing"
+
+	"github.com/ncruces/go-sqlite3/vfs"
+)
+
+func TestWrapOpen(t *testing.T) {
+	called := 0
+
+	WrapOpen(mockVFS{open: func(name string, flags vfs.OpenFlag) (vfs.File, vfs.OpenFlag, error) {
+		called++
+		return nil, flags, nil
+	}}, "", 0)
+
+	if called != 1 {
+		t.Error("open not called")
+	}
+
+	WrapOpenFilename(mockVFS{open: func(name string, flags vfs.OpenFlag) (vfs.File, vfs.OpenFlag, error) {
+		called++
+		return nil, flags, nil
+	}}, nil, 0)
+
+	if called != 2 {
+		t.Error("open not called")
+	}
+}
+
+func TestWrapOpenFilename(t *testing.T) {
+	called := 0
+
+	WrapOpen(mockVFSFilename{openFilename: func(name *vfs.Filename, flags vfs.OpenFlag) (vfs.File, vfs.OpenFlag, error) {
+		called++
+		return nil, flags, nil
+	}}, "", 0)
+
+	if called != 1 {
+		t.Error("openFilename not called")
+	}
+
+	WrapOpenFilename(mockVFSFilename{openFilename: func(name *vfs.Filename, flags vfs.OpenFlag) (vfs.File, vfs.OpenFlag, error) {
+		called++
+		return nil, flags, nil
+	}}, nil, 0)
+
+	if called != 2 {
+		t.Error("openFilename not called")
+	}
+}
+
+func TestWrapLockState(t *testing.T) {
+	called := 0
+
+	WrapLockState(mockFile{lockState: func() vfs.LockLevel {
+		called++
+		return 0
+	}})
+
+	if called != 1 {
+		t.Error("lockState not called")
+	}
+}
+
+func TestWrapPersistWAL(t *testing.T) {
+	persist := false
+	WrapSetPersistWAL(mockFile{setPersistWAL: func(b bool) { persist = b }}, true)
+	if !persist {
+		t.Error("setPersistWAL not called")
+	}
+
+	called := 0
+	WrapPersistWAL(mockFile{persistWAL: func() bool { called++; return persist }})
+	if !persist {
+		t.Error("persistWAL not called")
+	}
+	if called != 1 {
+	}
+}
+
+func TestWrapPowersafeOverwrite(t *testing.T) {
+	persist := false
+	WrapSetPowersafeOverwrite(mockFile{setPowersafeOverwrite: func(b bool) { persist = b }}, true)
+	if !persist {
+		t.Error("setPowersafeOverwrite not called")
+	}
+
+	called := 0
+	WrapPowersafeOverwrite(mockFile{powersafeOverwrite: func() bool { called++; return persist }})
+	if !persist {
+		t.Error("powersafeOverwrite not called")
+	}
+	if called != 1 {
+	}
+}
+
+func TestWrapChunkSize(t *testing.T) {
+	var chunk int
+
+	WrapChunkSize(mockFile{chunkSize: func(size int) {
+		chunk = size
+	}}, 5)
+
+	if chunk != 5 {
+		t.Error("chunkSize not called")
+	}
+}
+
+func TestWrapSizeHint(t *testing.T) {
+	var hint int64
+
+	WrapSizeHint(mockFile{sizeHint: func(size int64) error {
+		hint = size
+		return nil
+	}}, 5)
+
+	if hint != 5 {
+		t.Error("sizeHint not called")
+	}
+}
+
+func TestWrapHasMoved(t *testing.T) {
+	called := 0
+
+	WrapHasMoved(mockFile{hasMoved: func() (bool, error) {
+		called++
+		return false, nil
+	}})
+
+	if called != 1 {
+		t.Error("hasMoved not called")
+	}
+}
+
+func TestWrapOverwrite(t *testing.T) {
+	called := 0
+
+	WrapOverwrite(mockFile{overwrite: func() error {
+		called++
+		return nil
+	}})
+
+	if called != 1 {
+		t.Error("overwrite not called")
+	}
+}
+
+func TestWrapSyncSuper(t *testing.T) {
+	called := 0
+
+	WrapSyncSuper(mockFile{syncSuper: func(super string) error {
+		called++
+		return nil
+	}}, "")
+
+	if called != 1 {
+		t.Error("syncSuper not called")
+	}
+}
+
+func TestWrapCommitPhaseTwo(t *testing.T) {
+	called := 0
+
+	WrapCommitPhaseTwo(mockFile{commitPhaseTwo: func() error {
+		called++
+		return nil
+	}})
+
+	if called != 1 {
+		t.Error("commitPhaseTwo not called")
+	}
+}
+
+func TestWrapBatchAtomicWrite(t *testing.T) {
+	calledBegin := 0
+	calledCommit := 0
+	calledRollback := 0
+
+	f := mockFile{
+		begin:    func() error { calledBegin++; return nil },
+		commit:   func() error { calledCommit++; return nil },
+		rollback: func() error { calledRollback++; return nil },
+	}
+	WrapBeginAtomicWrite(f)
+	WrapCommitAtomicWrite(f)
+	WrapRollbackAtomicWrite(f)
+
+	if calledBegin != 1 {
+		t.Error("beginAtomicWrite not called")
+	}
+	if calledCommit != 1 {
+		t.Error("commitAtomicWrite not called")
+	}
+	if calledRollback != 1 {
+		t.Error("rollbackAtomicWrite not called")
+	}
+}
+
+func TestWrapCheckpoint(t *testing.T) {
+	calledStart := 0
+	calledDone := 0
+
+	f := mockFile{
+		ckptStart: func() { calledStart++ },
+		ckptDone:  func() { calledDone++ },
+	}
+	WrapCheckpointStart(f)
+	WrapCheckpointDone(f)
+
+	if calledStart != 1 {
+		t.Error("checkpointStart not called")
+	}
+	if calledDone != 1 {
+		t.Error("checkpointDone not called")
+	}
+}
+
+func TestWrapPragma(t *testing.T) {
+	called := 0
+
+	val, err := WrapPragma(mockFile{
+		pragma: func(name, value string) (string, error) {
+			called++
+			if name != "foo" || value != "bar" {
+				t.Error("wrong pragma arguments")
+			}
+			return "baz", nil
+		},
+	}, "foo", "bar")
+
+	if called != 1 {
+		t.Error("pragma not called")
+	}
+	if err != nil {
+		t.Error(err)
+	}
+	if val != "baz" {
+		t.Error("unexpected pragma return value")
+	}
+}
+
+func TestWrapBusyHandler(t *testing.T) {
+	called := 0
+
+	WrapBusyHandler(mockFile{
+		busyHandler: func(handler func() bool) {
+			handler()
+			called++
+		},
+	}, func() bool { return true })
+
+	if called != 1 {
+		t.Error("busyHandler not called")
+	}
+}
+
+type mockVFS struct {
+	open func(name string, flags vfs.OpenFlag) (vfs.File, vfs.OpenFlag, error)
+}
+
+func (m mockVFS) Open(name string, flags vfs.OpenFlag) (vfs.File, vfs.OpenFlag, error) {
+	return m.open(name, flags)
+}
+
+func (m mockVFS) Delete(name string, syncDir bool) error                 { panic("unimplemented") }
+func (m mockVFS) FullPathname(name string) (string, error)               { panic("unimplemented") }
+func (m mockVFS) Access(name string, flags vfs.AccessFlag) (bool, error) { panic("unimplemented") }
+
+type mockVFSFilename struct {
+	mockVFS
+	openFilename func(name *vfs.Filename, flags vfs.OpenFlag) (vfs.File, vfs.OpenFlag, error)
+}
+
+func (m mockVFSFilename) OpenFilename(name *vfs.Filename, flags vfs.OpenFlag) (vfs.File, vfs.OpenFlag, error) {
+	return m.openFilename(name, flags)
+}
+
+type mockFile struct {
+	lockState             func() vfs.LockLevel
+	persistWAL            func() bool
+	setPersistWAL         func(bool)
+	powersafeOverwrite    func() bool
+	setPowersafeOverwrite func(bool)
+	chunkSize             func(int)
+	sizeHint              func(int64) error
+	hasMoved              func() (bool, error)
+	overwrite             func() error
+	syncSuper             func(super string) error
+	commitPhaseTwo        func() error
+	begin                 func() error
+	commit                func() error
+	rollback              func() error
+	ckptStart             func()
+	ckptDone              func()
+	busyHandler           func(func() bool)
+	pragma                func(name, value string) (string, error)
+}
+
+func (m mockFile) LockState() vfs.LockLevel           { return m.lockState() }
+func (m mockFile) PersistWAL() bool                   { return m.persistWAL() }
+func (m mockFile) SetPersistWAL(v bool)               { m.setPersistWAL(v) }
+func (m mockFile) PowersafeOverwrite() bool           { return m.powersafeOverwrite() }
+func (m mockFile) SetPowersafeOverwrite(v bool)       { m.setPowersafeOverwrite(v) }
+func (m mockFile) ChunkSize(s int)                    { m.chunkSize(s) }
+func (m mockFile) SizeHint(s int64) error             { return m.sizeHint(s) }
+func (m mockFile) HasMoved() (bool, error)            { return m.hasMoved() }
+func (m mockFile) Overwrite() error                   { return m.overwrite() }
+func (m mockFile) SyncSuper(s string) error           { return m.syncSuper(s) }
+func (m mockFile) CommitPhaseTwo() error              { return m.commitPhaseTwo() }
+func (m mockFile) BeginAtomicWrite() error            { return m.begin() }
+func (m mockFile) CommitAtomicWrite() error           { return m.commit() }
+func (m mockFile) RollbackAtomicWrite() error         { return m.rollback() }
+func (m mockFile) CheckpointStart()                   { m.ckptStart() }
+func (m mockFile) CheckpointDone()                    { m.ckptDone() }
+func (m mockFile) BusyHandler(f func() bool)          { m.busyHandler(f) }
+func (m mockFile) Pragma(n, v string) (string, error) { return m.pragma(n, v) }
+
+func (m mockFile) Close() error                                    { panic("unimplemented") }
+func (m mockFile) ReadAt(p []byte, off int64) (n int, err error)   { panic("unimplemented") }
+func (m mockFile) WriteAt(p []byte, off int64) (n int, err error)  { panic("unimplemented") }
+func (m mockFile) Truncate(size int64) error                       { panic("unimplemented") }
+func (m mockFile) Sync(flags vfs.SyncFlag) error                   { panic("unimplemented") }
+func (m mockFile) Size() (int64, error)                            { panic("unimplemented") }
+func (m mockFile) Lock(lock vfs.LockLevel) error                   { panic("unimplemented") }
+func (m mockFile) Unlock(lock vfs.LockLevel) error                 { panic("unimplemented") }
+func (m mockFile) CheckReservedLock() (bool, error)                { panic("unimplemented") }
+func (m mockFile) SectorSize() int                                 { panic("unimplemented") }
+func (m mockFile) DeviceCharacteristics() vfs.DeviceCharacteristic { panic("unimplemented") }

value.go

@@ -1,9 +1,7 @@
 package sqlite3
 
 import (
-	"encoding/json"
 	"math"
-	"strconv"
 	"time"
 
 	"github.com/ncruces/go-sqlite3/internal/util"
@@ -31,9 +29,9 @@ func (v Value) Dup() *Value {
 // Close frees an SQL value previously obtained by [Value.Dup].
 //
 // https://sqlite.org/c3ref/value_dup.html
-func (dup *Value) Close() error {
-	dup.c.call("sqlite3_value_free", stk_t(dup.handle))
-	dup.handle = 0
+func (v *Value) Close() error {
+	v.c.call("sqlite3_value_free", stk_t(v.handle))
+	v.handle = 0
 	return nil
 }
 
@@ -162,27 +160,6 @@ func (v Value) Pointer() any {
 	return util.GetHandle(v.c.ctx, ptr)
 }
 
-// JSON parses a JSON-encoded value
-// and stores the result in the value pointed to by ptr.
-func (v Value) JSON(ptr any) error {
-	var data []byte
-	switch v.Type() {
-	case NULL:
-		data = []byte("null")
-	case TEXT:
-		data = v.RawText()
-	case BLOB:
-		data = v.RawBlob()
-	case INTEGER:
-		data = strconv.AppendInt(nil, v.Int64(), 10)
-	case FLOAT:
-		data = util.AppendNumber(nil, v.Float())
-	default:
-		panic(util.AssertErr())
-	}
-	return json.Unmarshal(data, ptr)
-}
-
 // NoChange returns true if and only if the value is unchanged
 // in a virtual table update operatiom.
 //

vfs/adiantum/adiantum.go

@@ -25,8 +25,8 @@ func (adiantumCreator) HBSH(key []byte) *hbsh.HBSH {
 func (adiantumCreator) KDF(text string) []byte {
 	if text == "" {
 		key := make([]byte, 32)
-		n, _ := rand.Read(key)
-		return key[:n]
+		rand.Read(key)
+		return key
 	}
 	return argon2.IDKey([]byte(text), []byte(pepper), 3, 64*1024, 4, 32)
 }

vfs/adiantum/adiantum_test.go

@@ -54,9 +54,8 @@ func Test_fileformat(t *testing.T) {
 func Benchmark_nokey(b *testing.B) {
 	tmp := filepath.Join(b.TempDir(), "test.db")
 	sqlite3.Initialize()
-	b.ResetTimer()
 
-	for range b.N {
+	for b.Loop() {
 		db, err := sqlite3.Open("file:" + filepath.ToSlash(tmp) + "?nolock=1")
 		if err != nil {
 			b.Fatal(err)
@@ -68,9 +67,8 @@ func Benchmark_nokey(b *testing.B) {
 func Benchmark_hexkey(b *testing.B) {
 	tmp := filepath.Join(b.TempDir(), "test.db")
 	sqlite3.Initialize()
-	b.ResetTimer()
 
-	for range b.N {
+	for b.Loop() {
 		db, err := sqlite3.Open("file:" + filepath.ToSlash(tmp) + "?nolock=1" +
 			"&vfs=adiantum&hexkey=e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")
 		if err != nil {
@@ -83,9 +81,8 @@ func Benchmark_hexkey(b *testing.B) {
 func Benchmark_textkey(b *testing.B) {
 	tmp := filepath.Join(b.TempDir(), "test.db")
 	sqlite3.Initialize()
-	b.ResetTimer()
 
-	for range b.N {
+	for b.Loop() {
 		db, err := sqlite3.Open("file:" + filepath.ToSlash(tmp) + "?nolock=1" +
 			"&vfs=adiantum&textkey=correct+horse+battery+staple")
 		if err != nil {

vfs/adiantum/example_test.go

@@ -45,8 +45,8 @@ func (hpolycCreator) KDF(secret string) []byte {
 	if secret == "" {
 		// No secret is given, generate a random key.
 		key := make([]byte, 32)
-		n, _ := rand.Read(key)
-		return key[:n]
+		rand.Read(key)
+		return key
 	}
 	// Hash the secret with a KDF.
 	return argon2.IDKey([]byte(secret), []byte("hpolyc"), 3, 64*1024, 4, 32)

vfs/adiantum/hbsh.go

@@ -20,7 +20,10 @@ type hbshVFS struct {
 
 func (h *hbshVFS) Open(name string, flags vfs.OpenFlag) (vfs.File, vfs.OpenFlag, error) {
 	// notest // OpenFilename is called instead
-	return nil, 0, sqlite3.CANTOPEN
+	if name == "" {
+		return h.OpenFilename(nil, flags)
+	}
+	return nil, flags, sqlite3.CANTOPEN
 }
 
 func (h *hbshVFS) OpenFilename(name *vfs.Filename, flags vfs.OpenFlag) (file vfs.File, _ vfs.OpenFlag, err error) {
@@ -160,10 +163,11 @@ func (h *hbshFile) WriteAt(p []byte, off int64) (n int, err error) {
 		if off > min || len(p[n:]) < blockSize {
 			// Partial block write: read-update-write.
 			m, err := h.File.ReadAt(h.block[:], min)
-			if m != blockSize {
-				if err != io.EOF {
-					return n, err
-				}
+			if m == blockSize {
+				data = h.hbsh.Decrypt(h.block[:], h.tweak[:])
+			} else if err != io.EOF {
+				return n, err
+			} else {
 				// Writing past the EOF.
 				// We're either appending an entirely new block,
 				// or the final block was only partially written.
@@ -171,8 +175,6 @@ func (h *hbshFile) WriteAt(p []byte, off int64) (n int, err error) {
 				// and is as good as corrupt.
 				// Either way, zero pad the file to the next block size.
 				clear(data)
-			} else {
-				data = h.hbsh.Decrypt(h.block[:], h.tweak[:])
 			}
 			if off > min {
 				data = data[off-min:]
@@ -223,16 +225,16 @@ func (h *hbshFile) SizeHint(size int64) error {
 	return vfsutil.WrapSizeHint(h.File, roundUp(size))
 }
 
+// Wrap optional methods.
+
 func (h *hbshFile) Unwrap() vfs.File {
-	return h.File
+	return h.File // notest
 }
 
 func (h *hbshFile) SharedMemory() vfs.SharedMemory {
-	return vfsutil.WrapSharedMemory(h.File)
+	return vfsutil.WrapSharedMemory(h.File) // notest
 }
 
-// Wrap optional methods.
-
 func (h *hbshFile) LockState() vfs.LockLevel {
 	return vfsutil.WrapLockState(h.File) // notest
 }

vfs/api.go

@@ -36,9 +36,9 @@ type VFSFilename interface {
 //
 // https://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)
+	io.Closer
+	io.ReaderAt
+	io.WriterAt
 	Truncate(size int64) error
 	Sync(flags SyncFlag) error
 	Size() (int64, error)

vfs/cksm.go

@@ -5,7 +5,6 @@ import (
 	"context"
 	_ "embed"
 	"encoding/binary"
-	"strconv"
 
 	"github.com/tetratelabs/wazero/api"
 
@@ -13,48 +12,30 @@ import (
 	"github.com/ncruces/go-sqlite3/util/sql3util"
 )
 
-func cksmWrapFile(name *Filename, flags OpenFlag, file File) File {
-	// Checksum only main databases and WALs.
-	if flags&(OPEN_MAIN_DB|OPEN_WAL) == 0 {
+func cksmWrapFile(file File, flags OpenFlag) File {
+	// Checksum only main databases.
+	if flags&OPEN_MAIN_DB == 0 {
 		return file
 	}
-
-	cksm := cksmFile{File: file}
-
-	if flags&OPEN_WAL != 0 {
-		main, _ := name.DatabaseFile().(cksmFile)
-		cksm.cksmFlags = main.cksmFlags
-	} else {
-		cksm.cksmFlags = new(cksmFlags)
-		cksm.isDB = true
-	}
-
-	return cksm
+	return &cksmFile{File: file}
 }
 
 type cksmFile struct {
 	File
-	*cksmFlags
-	isDB bool
-}
-
-type cksmFlags struct {
-	computeCksm bool
 	verifyCksm  bool
-	inCkpt      bool
-	pageSize    int
+	computeCksm bool
 }
 
-func (c cksmFile) ReadAt(p []byte, off int64) (n int, err error) {
+func (c *cksmFile) ReadAt(p []byte, off int64) (n int, err error) {
 	n, err = c.File.ReadAt(p, off)
 	p = p[:n]
 
-	if isHeader(c.isDB, p, off) {
+	if isHeader(p, off) {
 		c.init((*[100]byte)(p))
 	}
 
 	// Verify checksums.
-	if c.verifyCksm && !c.inCkpt && len(p) == c.pageSize {
+	if c.verifyCksm && sql3util.ValidPageSize(len(p)) {
 		cksm1 := cksmCompute(p[:len(p)-8])
 		cksm2 := *(*[8]byte)(p[len(p)-8:])
 		if cksm1 != cksm2 {
@@ -64,20 +45,20 @@ func (c cksmFile) ReadAt(p []byte, off int64) (n int, err error) {
 	return n, err
 }
 
-func (c cksmFile) WriteAt(p []byte, off int64) (n int, err error) {
-	if isHeader(c.isDB, p, off) {
+func (c *cksmFile) WriteAt(p []byte, off int64) (n int, err error) {
+	if isHeader(p, off) {
 		c.init((*[100]byte)(p))
 	}
 
 	// Compute checksums.
-	if c.computeCksm && !c.inCkpt && len(p) == c.pageSize {
+	if c.computeCksm && sql3util.ValidPageSize(len(p)) {
 		*(*[8]byte)(p[len(p)-8:]) = cksmCompute(p[:len(p)-8])
 	}
 
 	return c.File.WriteAt(p, off)
 }
 
-func (c cksmFile) Pragma(name string, value string) (string, error) {
+func (c *cksmFile) Pragma(name string, value string) (string, error) {
 	switch name {
 	case "checksum_verification":
 		b, ok := sql3util.ParseBool(value)
@@ -90,15 +71,15 @@ func (c cksmFile) Pragma(name string, value string) (string, error) {
 		return "1", nil
 
 	case "page_size":
-		if c.computeCksm {
+		if c.computeCksm && value != "" {
 			// Do not allow page size changes on a checksum database.
-			return strconv.Itoa(c.pageSize), nil
+			return "", nil
 		}
 	}
 	return "", _NOTFOUND
 }
 
-func (c cksmFile) DeviceCharacteristics() DeviceCharacteristic {
+func (c *cksmFile) DeviceCharacteristics() DeviceCharacteristic {
 	ret := c.File.DeviceCharacteristics()
 	if c.verifyCksm {
 		ret &^= IOCAP_SUBPAGE_READ
@@ -106,13 +87,8 @@ func (c cksmFile) DeviceCharacteristics() DeviceCharacteristic {
 	return ret
 }
 
-func (c cksmFile) fileControl(ctx context.Context, mod api.Module, op _FcntlOpcode, pArg ptr_t) _ErrorCode {
-	switch op {
-	case _FCNTL_CKPT_START:
-		c.inCkpt = true
-	case _FCNTL_CKPT_DONE:
-		c.inCkpt = false
-	case _FCNTL_PRAGMA:
+func (c *cksmFile) fileControl(ctx context.Context, mod api.Module, op _FcntlOpcode, pArg ptr_t) _ErrorCode {
+	if op == _FCNTL_PRAGMA {
 		rc := vfsFileControlImpl(ctx, mod, c, op, pArg)
 		if rc != _NOTFOUND {
 			return rc
@@ -121,24 +97,26 @@ func (c cksmFile) fileControl(ctx context.Context, mod api.Module, op _FcntlOpco
 	return vfsFileControlImpl(ctx, mod, c.File, op, pArg)
 }
 
-func (f *cksmFlags) init(header *[100]byte) {
-	f.pageSize = 256 * int(binary.LittleEndian.Uint16(header[16:18]))
-	if r := header[20] == 8; r != f.computeCksm {
-		f.computeCksm = r
-		f.verifyCksm = r
-	}
-	if !sql3util.ValidPageSize(f.pageSize) {
-		f.computeCksm = false
-		f.verifyCksm = false
+func (c *cksmFile) init(header *[100]byte) {
+	if r := header[20] == 8; r != c.computeCksm {
+		c.computeCksm = r
+		c.verifyCksm = r
 	}
 }
 
-func isHeader(isDB bool, p []byte, off int64) bool {
-	check := sql3util.ValidPageSize(len(p))
-	if isDB {
-		check = off == 0 && len(p) >= 100
+func (c *cksmFile) SharedMemory() SharedMemory {
+	if f, ok := c.File.(FileSharedMemory); ok {
+		return f.SharedMemory()
 	}
-	return check && bytes.HasPrefix(p, []byte("SQLite format 3\000"))
+	return nil
+}
+
+func (c *cksmFile) Unwrap() File {
+	return c.File
+}
+
+func isHeader(p []byte, off int64) bool {
+	return off == 0 && len(p) >= 100 && bytes.HasPrefix(p, []byte("SQLite format 3\000"))
 }
 
 func cksmCompute(a []byte) (cksm [8]byte) {
@@ -155,14 +133,3 @@ func cksmCompute(a []byte) (cksm [8]byte) {
 	binary.LittleEndian.PutUint32(cksm[4:8], s2)
 	return
 }
-
-func (c cksmFile) SharedMemory() SharedMemory {
-	if f, ok := c.File.(FileSharedMemory); ok {
-		return f.SharedMemory()
-	}
-	return nil
-}
-
-func (c cksmFile) Unwrap() File {
-	return c.File
-}

vfs/const.go

@@ -94,6 +94,10 @@ const (
 	OPEN_PRIVATECACHE  OpenFlag = 0x00040000 /* Ok for sqlite3_open_v2() */
 	OPEN_WAL           OpenFlag = 0x00080000 /* VFS only */
 	OPEN_NOFOLLOW      OpenFlag = 0x01000000 /* Ok for sqlite3_open_v2() */
+	_FLAG_ATOMIC       OpenFlag = 0x10000000
+	_FLAG_KEEP_WAL     OpenFlag = 0x20000000
+	_FLAG_PSOW         OpenFlag = 0x40000000
+	_FLAG_SYNC_DIR     OpenFlag = 0x80000000
 )
 
 // AccessFlag is a flag for the [VFS] Access method.

vfs/file.go

@@ -51,7 +51,7 @@ func (vfsOS) Delete(path string, syncDir bool) error {
 			return _OK
 		}
 		defer f.Close()
-		err = osSync(f, false, false)
+		err = osSync(f, 0, SYNC_FULL)
 		if err != nil {
 			return _IOERR_DIR_FSYNC
 		}
@@ -75,6 +75,9 @@ func (vfsOS) Access(name string, flags AccessFlag) (bool, error) {
 
 func (vfsOS) Open(name string, flags OpenFlag) (File, OpenFlag, error) {
 	// notest // OpenFilename is called instead
+	if name == "" {
+		return vfsOS{}.OpenFilename(nil, flags)
+	}
 	return nil, 0, _CANTOPEN
 }
 
@@ -128,27 +131,24 @@ func (vfsOS) OpenFilename(name *Filename, flags OpenFlag) (File, OpenFlag, error
 	}
 
 	file := vfsFile{
-		File:     f,
-		psow:     true,
-		atomic:   osBatchAtomic(f),
-		readOnly: flags&OPEN_READONLY != 0,
-		syncDir:  isUnix && isCreate && isJournl,
-		delete:   !isUnix && flags&OPEN_DELETEONCLOSE != 0,
-		shm:      NewSharedMemory(name.String()+"-shm", flags),
+		File:  f,
+		flags: flags | _FLAG_PSOW,
+		shm:   NewSharedMemory(name.String()+"-shm", flags),
+	}
+	if osBatchAtomic(f) {
+		file.flags |= _FLAG_ATOMIC
+	}
+	if isUnix && isCreate && isJournl {
+		file.flags |= _FLAG_SYNC_DIR
 	}
 	return &file, flags, nil
 }
 
 type vfsFile struct {
 	*os.File
-	shm      SharedMemory
-	lock     LockLevel
-	readOnly bool
-	keepWAL  bool
-	syncDir  bool
-	atomic   bool
-	delete   bool
-	psow     bool
+	shm   SharedMemory
+	lock  LockLevel
+	flags OpenFlag
 }
 
 var (
@@ -161,7 +161,7 @@ var (
 )
 
 func (f *vfsFile) Close() error {
-	if f.delete {
+	if !isUnix && f.flags&OPEN_DELETEONCLOSE != 0 {
 		defer os.Remove(f.Name())
 	}
 	if f.shm != nil {
@@ -180,21 +180,18 @@ func (f *vfsFile) WriteAt(p []byte, off int64) (n int, err error) {
 }
 
 func (f *vfsFile) Sync(flags SyncFlag) error {
-	dataonly := (flags & SYNC_DATAONLY) != 0
-	fullsync := (flags & 0x0f) == SYNC_FULL
-
-	err := osSync(f.File, fullsync, dataonly)
+	err := osSync(f.File, f.flags, flags)
 	if err != nil {
 		return err
 	}
-	if isUnix && f.syncDir {
-		f.syncDir = false
+	if isUnix && f.flags&_FLAG_SYNC_DIR != 0 {
+		f.flags ^= _FLAG_SYNC_DIR
 		d, err := os.Open(filepath.Dir(f.File.Name()))
 		if err != nil {
 			return nil
 		}
 		defer d.Close()
-		err = osSync(d, false, false)
+		err = osSync(f.File, f.flags, flags)
 		if err != nil {
 			return _IOERR_DIR_FSYNC
 		}
@@ -212,10 +209,10 @@ func (f *vfsFile) SectorSize() int {
 
 func (f *vfsFile) DeviceCharacteristics() DeviceCharacteristic {
 	ret := IOCAP_SUBPAGE_READ
-	if f.atomic {
+	if f.flags&_FLAG_ATOMIC != 0 {
 		ret |= IOCAP_BATCH_ATOMIC
 	}
-	if f.psow {
+	if f.flags&_FLAG_PSOW != 0 {
 		ret |= IOCAP_POWERSAFE_OVERWRITE
 	}
 	if runtime.GOOS == "windows" {
@@ -246,8 +243,20 @@ func (f *vfsFile) HasMoved() (bool, error) {
 	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) PersistWAL() bool                { return f.keepWAL }
-func (f *vfsFile) SetPowersafeOverwrite(psow bool) { f.psow = psow }
-func (f *vfsFile) SetPersistWAL(keepWAL bool)      { f.keepWAL = keepWAL }
+func (f *vfsFile) LockState() LockLevel     { return f.lock }
+func (f *vfsFile) PowersafeOverwrite() bool { return f.flags&_FLAG_PSOW != 0 }
+func (f *vfsFile) PersistWAL() bool         { return f.flags&_FLAG_KEEP_WAL != 0 }
+
+func (f *vfsFile) SetPowersafeOverwrite(psow bool) {
+	f.flags &^= _FLAG_PSOW
+	if psow {
+		f.flags |= _FLAG_PSOW
+	}
+}
+
+func (f *vfsFile) SetPersistWAL(keepWAL bool) {
+	f.flags &^= _FLAG_KEEP_WAL
+	if keepWAL {
+		f.flags |= _FLAG_KEEP_WAL
+	}
+}

vfs/filename.go

@@ -56,7 +56,7 @@ func (n *Filename) Journal() string {
 	return n.path("sqlite3_filename_journal")
 }
 
-// Journal returns the name of the corresponding WAL file.
+// WAL returns the name of the corresponding WAL file.
 //
 // https://sqlite.org/c3ref/filename_database.html
 func (n *Filename) WAL() string {

vfs/lock.go

@@ -41,7 +41,7 @@ func (f *vfsFile) Lock(lock LockLevel) error {
 	}
 
 	// Do not allow any kind of write-lock on a read-only database.
-	if f.readOnly && lock >= LOCK_RESERVED {
+	if lock >= LOCK_RESERVED && f.flags&OPEN_READONLY != 0 {
 		return _IOERR_LOCK
 	}
 

vfs/memdb/README.md

@@ -6,4 +6,7 @@ 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.
+- reader-writer concurrency is slightly improved.
+
+[`memdb.TestDB`](https://pkg.go.dev/github.com/ncruces/go-sqlite3/vfs/memdb#TestDB)
+is the preferred way to setup an in-memory database for testing.

vfs/memdb/api.go

@@ -10,6 +10,7 @@
 package memdb
 
 import (
+	"crypto/rand"
 	"fmt"
 	"net/url"
 	"sync"
@@ -74,11 +75,27 @@ func Delete(name string) {
 
 // TestDB creates an empty shared memory database for the test to use.
 // The database is automatically deleted when the test and all its subtests complete.
+// Returns a URI filename appropriate to call Open with.
 // Each subsequent call to TestDB returns a unique database.
+//
+//	func Test_something(t *testing.T) {
+//		t.Parallel()
+//		dsn := memdb.TestDB(t, url.Values{
+//			"_pragma": {"busy_timeout(1000)"},
+//		})
+//
+//		db, err := sql.Open("sqlite3", dsn)
+//		if err != nil {
+//			t.Fatal(err)
+//		}
+//		defer db.Close()
+//
+//		// ...
+//	}
 func TestDB(tb testing.TB, params ...url.Values) string {
 	tb.Helper()
 
-	name := fmt.Sprintf("%s_%p", tb.Name(), tb)
+	name := fmt.Sprintf("%s_%s", tb.Name(), rand.Text())
 	tb.Cleanup(func() { Delete(name) })
 	Create(name, nil)
 

vfs/memdb/memdb.go

@@ -2,40 +2,39 @@ package memdb
 
 import (
 	"io"
+	"strings"
 	"sync"
 	"time"
 
 	"github.com/ncruces/go-sqlite3"
+	"github.com/ncruces/go-sqlite3/util/vfsutil"
 	"github.com/ncruces/go-sqlite3/vfs"
 )
 
 const sectorSize = 65536
 
-// Ensure sectorSize is a multiple of 64K (the largest page size).
-var _ [0]struct{} = [sectorSize & 65535]struct{}{}
-
 type memVFS struct{}
 
 func (memVFS) Open(name string, flags vfs.OpenFlag) (vfs.File, vfs.OpenFlag, error) {
 	// For simplicity, we do not support reading or writing data
 	// across "sector" boundaries.
-	//
-	// This is not a problem for most SQLite file types:
-	// - databases, which only do page aligned reads/writes;
-	// - temp journals, as used by the sorter, which does the same:
-	//   https://github.com/sqlite/sqlite/blob/b74eb0/src/vdbesort.c#L409-L412
-	//
-	// We refuse to open all other file types,
-	// but returning OPEN_MEMORY means SQLite won't ask us to.
-	const types = vfs.OPEN_MAIN_DB | vfs.OPEN_TEMP_DB |
-		vfs.OPEN_TRANSIENT_DB | vfs.OPEN_TEMP_JOURNAL
-	if flags&types == 0 {
+	// This is not a problem for SQLite database files.
+	const databases = vfs.OPEN_MAIN_DB | vfs.OPEN_TEMP_DB | vfs.OPEN_TRANSIENT_DB
+
+	// Temp journals, as used by the sorter, use SliceFile.
+	if flags&vfs.OPEN_TEMP_JOURNAL != 0 {
+		return &vfsutil.SliceFile{}, flags | vfs.OPEN_MEMORY, nil
+	}
+
+	// Refuse to open all other file types.
+	// Returning OPEN_MEMORY means SQLite won't ask us to.
+	if flags&databases == 0 {
 		// notest // OPEN_MEMORY
 		return nil, flags, sqlite3.CANTOPEN
 	}
 
 	// A shared database has a name that begins with "/".
-	shared := len(name) > 1 && name[0] == '/'
+	shared := strings.HasPrefix(name, "/")
 
 	var db *memDB
 	if shared {
@@ -76,18 +75,16 @@ func (memVFS) FullPathname(name string) (string, error) {
 type memDB struct {
 	name string
 
+	// +checklocks:lockMtx
+	waiter *sync.Cond
 	// +checklocks:dataMtx
 	data []*[sectorSize]byte
-	// +checklocks:dataMtx
-	size int64
 
-	// +checklocks:memoryMtx
-	refs int32
-
-	shared   int32      // +checklocks:lockMtx
-	pending  bool       // +checklocks:lockMtx
-	reserved bool       // +checklocks:lockMtx
-	waiter   *sync.Cond // +checklocks:lockMtx
+	size     int64 // +checklocks:dataMtx
+	refs     int32 // +checklocks:memoryMtx
+	shared   int32 // +checklocks:lockMtx
+	pending  bool  // +checklocks:lockMtx
+	reserved bool  // +checklocks:lockMtx
 
 	lockMtx sync.Mutex
 	dataMtx sync.RWMutex
@@ -129,7 +126,7 @@ func (m *memFile) ReadAt(b []byte, off int64) (n int, err error) {
 	base := off / sectorSize
 	rest := off % sectorSize
 	have := int64(sectorSize)
-	if base == int64(len(m.data))-1 {
+	if m.size < off+int64(len(b)) {
 		have = modRoundUp(m.size, sectorSize)
 	}
 	n = copy(b, (*m.data[base])[rest:have])
@@ -150,22 +147,37 @@ func (m *memFile) WriteAt(b []byte, off int64) (n int, err error) {
 		m.data = append(m.data, new([sectorSize]byte))
 	}
 	n = copy((*m.data[base])[rest:], b)
+	if size := off + int64(n); size > m.size {
+		m.size = size
+	}
 	if n < len(b) {
 		// notest // assume writes are page aligned
 		return n, io.ErrShortWrite
 	}
-	if size := off + int64(len(b)); size > m.size {
-		m.size = size
-	}
 	return n, nil
 }
 
+func (m *memFile) Size() (int64, error) {
+	m.dataMtx.RLock()
+	defer m.dataMtx.RUnlock()
+	return m.size, nil
+}
+
 func (m *memFile) Truncate(size int64) error {
 	m.dataMtx.Lock()
 	defer m.dataMtx.Unlock()
 	return m.truncate(size)
 }
 
+func (m *memFile) SizeHint(size int64) error {
+	m.dataMtx.Lock()
+	defer m.dataMtx.Unlock()
+	if size > m.size {
+		return m.truncate(size)
+	}
+	return nil
+}
+
 // +checklocks:m.dataMtx
 func (m *memFile) truncate(size int64) error {
 	if size < m.size {
@@ -185,16 +197,6 @@ func (m *memFile) truncate(size int64) error {
 	return nil
 }
 
-func (m *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
@@ -278,31 +280,24 @@ func (m *memFile) CheckReservedLock() (bool, error) {
 	return m.reserved, nil
 }
 
-func (m *memFile) SectorSize() int {
+func (m *memFile) LockState() vfs.LockLevel {
+	return m.lock
+}
+
+func (*memFile) Sync(flag vfs.SyncFlag) error { return nil }
+
+func (*memFile) SectorSize() int {
 	// notest // IOCAP_POWERSAFE_OVERWRITE
 	return sectorSize
 }
 
-func (m *memFile) DeviceCharacteristics() vfs.DeviceCharacteristic {
+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
 }

vfs/mvcc/README.md

@@ -0,0 +1,15 @@
+# Go `mvcc` SQLite VFS
+
+This package implements the **EXPERIMENTAL** `"mvcc"` in-memory SQLite VFS.
+
+It has some benefits over the [`"memdb"`](../memdb/README.md) VFS:
+- panics do not corrupt a shared database,
+- single-writer not blocked by readers,
+- readers never block,
+- instant snapshots.
+
+[`mvcc.TestDB`](https://pkg.go.dev/github.com/ncruces/go-sqlite3/vfs/mvcc#TestDB)
+is the preferred way to setup an in-memory database for testing
+when you intend to leverage snapshots,
+e.g. to setup many independent copies of a database,
+such as one for each subtest.

vfs/mvcc/api.go

@@ -0,0 +1,149 @@
+// Package mvcc implements the "mvcc" SQLite VFS.
+//
+// The "mvcc" [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 mvcc registers the VFS:
+//
+//	import _ "github.com/ncruces/go-sqlite3/vfs/mvcc"
+package mvcc
+
+import (
+	"crypto/rand"
+	"fmt"
+	"net/url"
+	"strings"
+	"sync"
+	"testing"
+
+	"github.com/ncruces/go-sqlite3/vfs"
+	"github.com/ncruces/wbt"
+)
+
+func init() {
+	vfs.Register("mvcc", mvccVFS{})
+}
+
+var (
+	memoryMtx sync.Mutex
+	// +checklocks:memoryMtx
+	memoryDBs = map[string]*mvccDB{}
+)
+
+// Create creates a shared memory database,
+// using a snapshot as its initial contents.
+func Create(name string, snapshot Snapshot) {
+	memoryMtx.Lock()
+	defer memoryMtx.Unlock()
+
+	memoryDBs[name] = &mvccDB{
+		refs: 1,
+		name: name,
+		data: snapshot.Tree,
+	}
+}
+
+// Delete deletes a shared memory database.
+func Delete(name string) {
+	name = getName(name)
+
+	memoryMtx.Lock()
+	defer memoryMtx.Unlock()
+	delete(memoryDBs, name)
+}
+
+// Snapshot represents a database snapshot.
+type Snapshot struct {
+	*wbt.Tree[int64, string]
+}
+
+// NewSnapshot creates a snapshot from data.
+func NewSnapshot(data string) Snapshot {
+	var tree *wbt.Tree[int64, string]
+
+	// Convert data from WAL/2 to rollback journal.
+	if len(data) >= 20 && (false ||
+		data[18] == 2 && data[19] == 2 ||
+		data[18] == 3 && data[19] == 3) {
+		tree = tree.
+			Put(0, data[:18]).
+			Put(18, "\001\001").
+			Put(20, data[20:])
+	} else if len(data) > 0 {
+		tree = tree.Put(0, data)
+	}
+
+	return Snapshot{tree}
+}
+
+// TakeSnapshot takes a snapshot of a database.
+// Name may be a URI filename.
+func TakeSnapshot(name string) Snapshot {
+	name = getName(name)
+
+	memoryMtx.Lock()
+	defer memoryMtx.Unlock()
+	db := memoryDBs[name]
+	if db == nil {
+		return Snapshot{}
+	}
+
+	db.mtx.Lock()
+	defer db.mtx.Unlock()
+	return Snapshot{db.data}
+}
+
+// TestDB creates a shared database from a snapshot for the test to use.
+// The database is automatically deleted when the test and all its subtests complete.
+// Returns a URI filename appropriate to call Open with.
+// Each subsequent call to TestDB returns a unique database.
+//
+//	func Test_something(t *testing.T) {
+//		t.Parallel()
+//		dsn := mvcc.TestDB(t, snapshot, url.Values{
+//			"_pragma": {"busy_timeout(1000)"},
+//		})
+//
+//		db, err := sql.Open("sqlite3", dsn)
+//		if err != nil {
+//			t.Fatal(err)
+//		}
+//		defer db.Close()
+//
+//		// ...
+//	}
+func TestDB(tb testing.TB, snapshot Snapshot, params ...url.Values) string {
+	tb.Helper()
+
+	name := fmt.Sprintf("%s_%s", tb.Name(), rand.Text())
+	tb.Cleanup(func() { Delete(name) })
+	Create(name, snapshot)
+
+	p := url.Values{"vfs": {"mvcc"}}
+	for _, v := range params {
+		for k, v := range v {
+			for _, v := range v {
+				p.Add(k, v)
+			}
+		}
+	}
+
+	return (&url.URL{
+		Scheme:   "file",
+		OmitHost: true,
+		Path:     "/" + name,
+		RawQuery: p.Encode(),
+	}).String()
+}
+
+func getName(dsn string) string {
+	u, err := url.Parse(dsn)
+	if err == nil &&
+		u.Scheme == "file" &&
+		strings.HasPrefix(u.Path, "/") &&
+		u.Query().Get("vfs") == "mvcc" {
+		return u.Path[1:]
+	}
+	return dsn
+}

vfs/mvcc/example_test.go

@@ -0,0 +1,50 @@
+package mvcc_test
+
+import (
+	"database/sql"
+	_ "embed"
+	"fmt"
+	"log"
+
+	_ "github.com/ncruces/go-sqlite3/driver"
+	_ "github.com/ncruces/go-sqlite3/embed"
+	"github.com/ncruces/go-sqlite3/vfs/mvcc"
+)
+
+//go:embed testdata/test.db
+var testDB string
+
+func Example() {
+	mvcc.Create("test.db", mvcc.NewSnapshot(testDB))
+
+	db, err := sql.Open("sqlite3", "file:/test.db?vfs=mvcc")
+	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/mvcc/mvcc.go

@@ -0,0 +1,323 @@
+package mvcc
+
+import (
+	"io"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/ncruces/go-sqlite3"
+	"github.com/ncruces/go-sqlite3/util/vfsutil"
+	"github.com/ncruces/go-sqlite3/vfs"
+	"github.com/ncruces/wbt"
+)
+
+type mvccVFS struct{}
+
+func (mvccVFS) Open(name string, flags vfs.OpenFlag) (vfs.File, vfs.OpenFlag, error) {
+	// Temporary files use SliceFile.
+	if name == "" || flags&vfs.OPEN_DELETEONCLOSE != 0 {
+		return &vfsutil.SliceFile{}, flags | vfs.OPEN_MEMORY, nil
+	}
+
+	// Only main databases benefit from multiversion concurrency control.
+	// Refuse to open all other file types.
+	// Returning OPEN_MEMORY means SQLite won't ask us to.
+	if flags&vfs.OPEN_MAIN_DB == 0 {
+		// notest // OPEN_MEMORY
+		return nil, flags, sqlite3.CANTOPEN
+	}
+
+	// A shared database has a name that begins with "/".
+	shared := strings.HasPrefix(name, "/")
+
+	var db *mvccDB
+	if shared {
+		name = name[1:]
+		memoryMtx.Lock()
+		defer memoryMtx.Unlock()
+		db = memoryDBs[name]
+	}
+	if db == nil {
+		if flags&vfs.OPEN_CREATE == 0 {
+			return nil, flags, sqlite3.CANTOPEN
+		}
+		db = &mvccDB{name: name}
+	}
+	if shared {
+		db.refs++ // +checklocksforce: memoryMtx is held
+		memoryDBs[name] = db
+	}
+
+	return &mvccFile{
+		mvccDB:   db,
+		readOnly: flags&vfs.OPEN_READONLY != 0,
+	}, flags | vfs.OPEN_MEMORY, nil
+}
+
+func (mvccVFS) Delete(name string, dirSync bool) error {
+	return sqlite3.IOERR_DELETE_NOENT // used to delete journals
+}
+
+func (mvccVFS) Access(name string, flag vfs.AccessFlag) (bool, error) {
+	return false, nil // used to check for journals
+}
+
+func (mvccVFS) FullPathname(name string) (string, error) {
+	return name, nil
+}
+
+type mvccDB struct {
+	data   *wbt.Tree[int64, string] // +checklocks:mtx
+	owner  *mvccFile                // +checklocks:mtx
+	waiter *sync.Cond               // +checklocks:mtx
+
+	name string
+	refs int // +checklocks:memoryMtx
+	mtx  sync.Mutex
+}
+
+func (m *mvccDB) release() {
+	memoryMtx.Lock()
+	defer memoryMtx.Unlock()
+	if m.refs--; m.refs == 0 && m == memoryDBs[m.name] {
+		delete(memoryDBs, m.name)
+	}
+}
+
+type mvccFile struct {
+	*mvccDB
+	data     *wbt.Tree[int64, string]
+	lock     vfs.LockLevel
+	readOnly bool
+}
+
+var (
+	// Ensure these interfaces are implemented:
+	_ vfs.FileLockState      = &mvccFile{}
+	_ vfs.FileCommitPhaseTwo = &mvccFile{}
+)
+
+func (m *mvccFile) Close() error {
+	// Relase ownership, discard changes.
+	m.release()
+	m.data = nil
+	m.lock = vfs.LOCK_NONE
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+	if m.owner == m {
+		m.owner = nil
+	}
+	return nil
+}
+
+func (m *mvccFile) ReadAt(b []byte, off int64) (n int, err error) {
+	// If unlocked, use a snapshot of the database.
+	data := m.data
+	if m.lock == vfs.LOCK_NONE {
+		m.mtx.Lock()
+		defer m.mtx.Unlock()
+		data = m.mvccDB.data
+	}
+
+	for k, v := range data.AscendFloor(off) {
+		if i := k - off; i >= 0 {
+			if +i > int64(n) {
+				// Missing data.
+				clear(b[n:])
+			}
+			if +i < int64(len(b)) {
+				// Copy prefix.
+				n = copy(b[+i:], v) + int(i)
+			}
+		} else {
+			if -i < int64(len(v)) {
+				// Copy suffix.
+				n = copy(b, v[-i:])
+			}
+		}
+		if n >= len(b) {
+			return n, nil
+		}
+	}
+	return n, io.EOF
+}
+
+func (m *mvccFile) WriteAt(b []byte, off int64) (n int, err error) {
+	// If unlocked, take a snapshot of the database.
+	data := m.data
+	if m.lock == vfs.LOCK_NONE {
+		m.mtx.Lock()
+		defer m.mtx.Unlock()
+		data = m.mvccDB.data
+		m.lock = vfs.LOCK_EXCLUSIVE + 1 // UNKNOWN_LOCK
+	}
+
+	next := off + int64(len(b))
+	for k, v := range data.AscendFloor(off) {
+		if k >= next {
+			break
+		}
+		switch {
+		case k > off:
+			// Delete overlap.
+			data = data.Delete(k)
+		case k < off && off < k+int64(len(v)):
+			// Reinsert prefix.
+			data = data.Put(k, v[:off-k])
+		}
+		if k+int64(len(v)) > next {
+			// Reinsert suffix.
+			data = data.Put(next, v[next-k:])
+		}
+	}
+
+	m.data = data.Put(off, string(b))
+	return len(b), nil
+}
+
+func (m *mvccFile) Size() (int64, error) {
+	// If unlocked, use a snapshot of the database.
+	data := m.data
+	if m.lock == vfs.LOCK_NONE {
+		m.mtx.Lock()
+		defer m.mtx.Unlock()
+		data = m.mvccDB.data
+	}
+
+	if data == nil {
+		return 0, nil
+	}
+	data = data.Max()
+	return data.Key() + int64(len(data.Value())), nil
+}
+
+func (m *mvccFile) Truncate(size int64) error {
+	// If unlocked, take a snapshot of the database.
+	data := m.data
+	if m.lock == vfs.LOCK_NONE {
+		m.mtx.Lock()
+		defer m.mtx.Unlock()
+		data = m.mvccDB.data
+		m.lock = vfs.LOCK_EXCLUSIVE + 1 // UNKNOWN_LOCK
+	}
+
+	for data != nil && data.Key() >= size {
+		data = data.Left()
+	}
+	for k := range data.AscendCeil(size) {
+		data = data.Delete(k)
+	}
+	m.data = data
+	return nil
+}
+
+func (m *mvccFile) Lock(lock vfs.LockLevel) error {
+	if m.lock >= lock {
+		return nil
+	}
+
+	if m.readOnly && lock >= vfs.LOCK_RESERVED {
+		return sqlite3.IOERR_LOCK
+	}
+
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+
+	// Take a snapshot of the database.
+	if lock == vfs.LOCK_SHARED {
+		m.data = m.mvccDB.data
+		m.lock = lock
+		return nil
+	}
+	// We are the owners.
+	if m.owner == m {
+		m.lock = lock
+		return nil
+	}
+	// Someone else is the owner.
+	if m.owner != nil {
+		before := time.Now()
+		if m.waiter == nil {
+			m.waiter = sync.NewCond(&m.mtx)
+		}
+		defer time.AfterFunc(time.Millisecond, m.waiter.Broadcast).Stop()
+		for m.owner != nil {
+			// Our snapshot is invalid.
+			if m.data != m.mvccDB.data {
+				return sqlite3.BUSY_SNAPSHOT
+			}
+			if time.Since(before) > time.Millisecond {
+				return sqlite3.BUSY
+			}
+			m.waiter.Wait()
+		}
+	}
+	// Our snapshot is invalid.
+	if m.data != m.mvccDB.data {
+		return sqlite3.BUSY_SNAPSHOT
+	}
+	// Take ownership.
+	m.lock = lock
+	m.owner = m
+	return nil
+}
+
+func (m *mvccFile) Unlock(lock vfs.LockLevel) error {
+	if m.lock <= lock {
+		return nil
+	}
+
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+
+	// Relase ownership, commit changes.
+	if m.owner == m {
+		m.owner = nil
+		m.mvccDB.data = m.data
+		if m.waiter != nil {
+			m.waiter.Broadcast()
+		}
+	}
+	m.lock = lock
+	return nil
+}
+
+func (m *mvccFile) CheckReservedLock() (bool, error) {
+	// notest // OPEN_MEMORY
+	if m.lock >= vfs.LOCK_RESERVED {
+		return true, nil
+	}
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+	return m.owner != nil, nil
+}
+
+func (m *mvccFile) CommitPhaseTwo() error {
+	// Modified without lock, commit changes.
+	if m.lock > vfs.LOCK_EXCLUSIVE {
+		m.mtx.Lock()
+		defer m.mtx.Unlock()
+		m.mvccDB.data = m.data
+	}
+	return nil
+}
+
+func (m *mvccFile) LockState() vfs.LockLevel {
+	return m.lock
+}
+
+func (*mvccFile) Sync(flag vfs.SyncFlag) error { return nil }
+
+func (*mvccFile) SectorSize() int {
+	// notest // safe default
+	return 0
+}
+
+func (*mvccFile) DeviceCharacteristics() vfs.DeviceCharacteristic {
+	return vfs.IOCAP_ATOMIC |
+		vfs.IOCAP_SEQUENTIAL |
+		vfs.IOCAP_SAFE_APPEND |
+		vfs.IOCAP_POWERSAFE_OVERWRITE |
+		vfs.IOCAP_SUBPAGE_READ
+}

vfs/mvcc/mvcc_test.go

@@ -0,0 +1,29 @@
+package mvcc
+
+import (
+	_ "embed"
+	"testing"
+
+	"github.com/ncruces/go-sqlite3"
+	_ "github.com/ncruces/go-sqlite3/embed"
+	_ "github.com/ncruces/go-sqlite3/internal/testcfg"
+)
+
+//go:embed testdata/wal.db
+var walDB string
+
+func Test_wal(t *testing.T) {
+	t.Parallel()
+	dsn := TestDB(t, NewSnapshot(walDB))
+
+	db, err := sqlite3.Open(dsn)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+
+	err = db.Exec(`CREATE TABLE users (id INT, name VARCHAR(10))`)
+	if err != nil {
+		t.Fatal(err)
+	}
+}

vfs/os_darwin.go

@@ -23,12 +23,26 @@ type flocktimeout_t struct {
 	timeout unix.Timespec
 }
 
-func osSync(file *os.File, fullsync, _ /*dataonly*/ bool) error {
-	if fullsync {
-		return file.Sync()
+func osSync(file *os.File, open OpenFlag, sync SyncFlag) error {
+	var cmd int
+	if sync&SYNC_FULL == SYNC_FULL {
+		// For rollback journals all we really need is a barrier.
+		if open&OPEN_MAIN_JOURNAL != 0 {
+			cmd = unix.F_BARRIERFSYNC
+		} else {
+			cmd = unix.F_FULLFSYNC
+		}
 	}
+
+	fd := file.Fd()
 	for {
-		err := unix.Fsync(int(file.Fd()))
+		err := error(unix.ENOTSUP)
+		if cmd != 0 {
+			_, err = unix.FcntlInt(fd, cmd, 0)
+		}
+		if err == unix.ENOTSUP {
+			err = unix.Fsync(int(fd))
+		}
 		if err != unix.EINTR {
 			return err
 		}