Updated dependencies.

binaryen-version_124.
Bump actions/setup-go from 5 to 6 (#318 )
2026-01-19 09:04:16 +00:00 · 2025-09-08 13:59:41 +01:00 · 2025-09-08 12:23:58 +01:00 · 2025-09-05 00:25:35 +02:00 · 2025-09-03 09:03:59 +02:00 · 2025-09-01 12:57:33 +02:00
72 changed files with 1883 additions and 863 deletions
--- a/.github/workflows/libc.yml
+++ b/.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
--- a/.github/workflows/repro.yml
+++ b/.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: |
--- a/.github/workflows/test.yml
+++ b/.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
--- a/driver/driver.go
+++ b/driver/driver.go
@@ -604,15 +604,6 @@ 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 (
@@ -648,10 +639,20 @@ func scanFromDecl(decl string) scantype {
 	return _ANY
 }

+type rows struct {
+	ctx context.Context
+	*stmt
+	names []string
+	types []string
+	nulls []bool
+	scans []scantype
+}
+
 var (
 	// Ensure these interfaces are implemented:
 	_ driver.RowsColumnTypeDatabaseTypeName = &rows{}
 	_ driver.RowsColumnTypeNullable         = &rows{}
+	// _ driver.RowsColumnScanner           = &rows{}
 )

 func (r *rows) Close() error {
@@ -740,7 +741,7 @@ 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
@@ -830,3 +831,23 @@ func (r *rows) Next(dest []driver.Value) error {
 	}
 	return nil
 }
+
+func (r *rows) ScanColumn(dest any, index int) error {
+	// notest // Go 1.26
+	var ptr *time.Time
+	switch d := dest.(type) {
+	case *time.Time:
+		ptr = d
+	case *sql.NullTime:
+		ptr = &d.Time
+	case *sql.Null[time.Time]:
+		ptr = &d.V
+	default:
+		return driver.ErrSkip
+	}
+	if t := r.Stmt.ColumnTime(index, r.tmRead); !t.IsZero() {
+		*ptr = t
+		return nil
+	}
+	return driver.ErrSkip
+}
--- a/embed/README.md
+++ b/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:
--- a/embed/bcw2/bcw2.wasm
+++ b/embed/bcw2/bcw2.wasm
--- a/embed/bcw2/build.sh
+++ b/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
--- a/embed/bcw2/go.mod
+++ b/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 v0.28.0

 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
 )
--- a/embed/bcw2/go.sum
+++ b/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 v0.28.0 h1:AQVTUPgfamONl09LS+4rGFbHmLKM8/QrJJJi1UukjEQ=
+github.com/ncruces/go-sqlite3 v0.28.0/go.mod h1:WqvLhYwtEiZzg1H8BIeahUv/DxbmR+3xG5jDHDiBAGk=
 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 v0.28.0 h1:rhazDwis8INMIwQ4tpjLDzUhx6RlXqZNPEM0huQojng=
+golang.org/x/text v0.28.0/go.mod h1:U8nCwOR8jO/marOQ0QbDiOngZVEBB7MAiitBuMjXiNU=
--- a/embed/build.sh
+++ b/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
--- a/embed/init_test.go
+++ b/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)
 	}
 }
--- a/embed/sqlite3.wasm
+++ b/embed/sqlite3.wasm
--- a/ext/README.md
+++ b/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.
--- a/ext/fileio/fileio.go
+++ b/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 {
--- a/ext/serdes/serdes.go
+++ b/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
-}
--- a/ext/serdes/serdes_test.go
+++ b/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
 	}
--- a/ext/serdes/testdata/wal.db
+++ b/ext/serdes/testdata/wal.db
--- a/ext/unicode/unicode.go
+++ b/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
--- a/ext/zorder/zorder.go
+++ b/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 {
--- a/ext/zorder/zorder_test.go
+++ b/ext/zorder/zorder_test.go
@@ -12,7 +12,7 @@ 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)

@@ -57,7 +57,7 @@ func TestRegister_zorder(t *testing.T) {
 	}
 }

-func TestRegister_unzorder(t *testing.T) {
+func Test_unzorder(t *testing.T) {
 	t.Parallel()
 	tmp := memdb.TestDB(t)

@@ -85,7 +85,7 @@ 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)

@@ -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()
+	tmp := memdb.TestDB(t)
+
+	db, err := driver.Open(tmp, 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")
+	}
+}
--- a/func.go
+++ b/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"))
-}
--- a/go.mod
+++ b/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/aa v0.3.3
 	github.com/ncruces/julianday v1.0.0
 	github.com/ncruces/sort v0.1.5
 	github.com/tetratelabs/wazero v1.9.0
-	golang.org/x/crypto v0.40.0
-	golang.org/x/sys v0.34.0
+	golang.org/x/crypto v0.41.0
+	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/sync v0.17.0 // test
+	golang.org/x/text v0.29.0 // ext/unicode
 	lukechampine.com/adiantum v1.1.1 // vfs/adiantum
 )

--- a/go.sum
+++ b/go.sum
@@ -2,6 +2,8 @@ github.com/dchest/siphash v1.2.3 h1:QXwFc8cFOR2dSa/gE6o/HokBMWtLUaNDVd+22aKHeEA=
 github.com/dchest/siphash v1.2.3/go.mod h1:0NvQU092bT0ipiFN++/rXm69QG9tVxLAlQHIXMPAkHc=
 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/aa v0.3.3 h1:f5Y9nQcbKHEaBks7kIcLmUgsDbokRPRCzNCx6XVGEr0=
+github.com/ncruces/aa v0.3.3/go.mod h1:ctOw1LVqfuqzqg2S9LlR045bLAiXtaTiPMCL3zzl7Ik=
 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=
@@ -10,13 +12,13 @@ github.com/psanford/httpreadat v0.1.0 h1:VleW1HS2zO7/4c7c7zNl33fO6oYACSagjJIyMIw
 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 v0.41.0 h1:WKYxWedPGCTVVl5+WHSSrOBT0O8lx32+zxmHxijgXp4=
+golang.org/x/crypto v0.41.0/go.mod h1:pO5AFd7FA68rFak7rOAGVuygIISepHftHnr8dr6+sUc=
+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=
--- a/gormlite/go.mod
+++ b/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 v0.28.0
+	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
 )
--- a/gormlite/go.sum
+++ b/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 v0.28.0 h1:AQVTUPgfamONl09LS+4rGFbHmLKM8/QrJJJi1UukjEQ=
+github.com/ncruces/go-sqlite3 v0.28.0/go.mod h1:WqvLhYwtEiZzg1H8BIeahUv/DxbmR+3xG5jDHDiBAGk=
 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=
--- a/gormlite/test.sh
+++ b/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/

--- a/gormlite/tests.patch
+++ b/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"
--- a/internal/alloc/alloc_unix.go
+++ b/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.
--- a/internal/alloc/alloc_windows.go
+++ b/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.
--- a/internal/util/func.go
+++ b/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) {
--- a/sqlite3/busy_timeout.patch
+++ b/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 ){
--- a/sqlite3/download.sh
+++ b/sqlite3/download.sh
@@ -3,7 +3,7 @@ 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"
 unzip -d . sqlite-amalgamation-*.zip
 mv sqlite-amalgamation-*/sqlite3.c .
 mv sqlite-amalgamation-*/sqlite3.h .
@@ -19,30 +19,30 @@ 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
--- a/sqlite3/libc/build.sh
+++ b/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
--- a/sqlite3/libc/libc.wasm
+++ b/sqlite3/libc/libc.wasm
--- a/sqlite3/libc/libc.wat
+++ b/sqlite3/libc/libc.wat
--- a/sqlite3/libc/libc_test.go
+++ b/sqlite3/libc/libc_test.go
@@ -8,7 +8,6 @@ import (
 	"os"
 	"strings"
 	"testing"
-	"unicode/utf8"

 	"github.com/tetratelabs/wazero"
 	"github.com/tetratelabs/wazero/api"
@@ -750,15 +749,7 @@ 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 +769,6 @@ 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 +778,7 @@ 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 +821,21 @@ 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)
+}
--- a/sqlite3/libc/string.h
+++ b/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);
--- a/sqlite3/tools.sh
+++ b/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"
--- a/sqlite3/vfs_find.patch
+++ b/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;
 }
--- a/tests/bradfitz/sql_test.go
+++ b/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)
--- a/tests/conn_test.go
+++ b/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()

--- a/tests/parallel/parallel_test.go
+++ b/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
+	}
+
+	mvcc.Create("test.db", "")
+	name := "file:/test.db?vfs=mvcc" +
+		"&_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) {
+	mvcc.Create("test.db", "")
+	name := "file:/test.db?vfs=mvcc" +
+		"&_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 {
--- a/util/ioutil/seek.go
+++ b/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()
--- a/util/osutil/osfs.go
+++ b/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)
 }
--- a/util/sql3util/wasm/build.sh
+++ b/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
--- a/util/sql3util/wasm/sql3parse_table.wasm
+++ b/util/sql3util/wasm/sql3parse_table.wasm
--- a/util/vfsutil/slice.go
+++ b/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
+}
--- a/util/vfsutil/wrap.go
+++ b/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 {
--- a/util/vfsutil/wrap_test.go
+++ b/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") }
--- a/value.go
+++ b/value.go
@@ -31,9 +31,9 @@ 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
 }

--- a/vfs/adiantum/hbsh.go
+++ b/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
 }
--- a/vfs/api.go
+++ b/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)
--- a/vfs/cksm.go
+++ b/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
-}
--- a/vfs/file.go
+++ b/vfs/file.go
@@ -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
 }

--- a/vfs/filename.go
+++ b/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 {
--- a/vfs/memdb/memdb.go
+++ b/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
 }
--- a/vfs/mvcc/README.md
+++ b/vfs/mvcc/README.md
@@ -0,0 +1,9 @@
+# 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.
--- a/vfs/mvcc/api.go
+++ b/vfs/mvcc/api.go
@@ -0,0 +1,67 @@
+// 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 (
+	"sync"
+
+	"github.com/ncruces/go-sqlite3/vfs"
+)
+
+func init() {
+	vfs.Register("mvcc", mvccVFS{})
+}
+
+var (
+	memoryMtx sync.Mutex
+	// +checklocks:memoryMtx
+	memoryDBs = map[string]*mvccDB{}
+)
+
+// Create creates a shared memory database,
+// using data as its initial contents.
+func Create(name string, data string) {
+	memoryMtx.Lock()
+	defer memoryMtx.Unlock()
+
+	db := &mvccDB{
+		refs: 1,
+		name: name,
+	}
+	memoryDBs[name] = db
+	if len(data) == 0 {
+		return
+	}
+	// 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) {
+		db.data = db.data.
+			Put(0, data[:18]).
+			Put(18, "\001\001").
+			Put(20, data[20:])
+	} else {
+		db.data = db.data.Put(0, data)
+	}
+}
+
+// Delete deletes a shared memory database.
+func Delete(name string) {
+	memoryMtx.Lock()
+	defer memoryMtx.Unlock()
+	delete(memoryDBs, name)
+}
+
+// Snapshot stores a snapshot of database src into dst.
+func Snapshot(dst, src string) {
+	memoryMtx.Lock()
+	defer memoryMtx.Unlock()
+	memoryDBs[dst] = memoryDBs[src].fork()
+}
--- a/vfs/mvcc/example_test.go
+++ b/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", 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
+}
--- a/vfs/mvcc/mvcc.go
+++ b/vfs/mvcc/mvcc.go
@@ -0,0 +1,333 @@
+package mvcc
+
+import (
+	"io"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/ncruces/aa"
+	"github.com/ncruces/go-sqlite3"
+	"github.com/ncruces/go-sqlite3/util/vfsutil"
+	"github.com/ncruces/go-sqlite3/vfs"
+)
+
+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   *aa.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)
+	}
+}
+
+func (m *mvccDB) fork() *mvccDB {
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+	return &mvccDB{
+		refs: 1,
+		name: m.name,
+		data: m.data,
+	}
+}
+
+type mvccFile struct {
+	*mvccDB
+	data     *aa.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
+}
--- a/vfs/mvcc/mvcc_test.go
+++ b/vfs/mvcc/mvcc_test.go
@@ -0,0 +1,30 @@
+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()
+
+	Create("test.db", walDB)
+
+	db, err := sqlite3.Open("file:/test.db?vfs=mvcc")
+	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)
+	}
+}
--- a/vfs/mvcc/testdata/test.db
+++ b/vfs/mvcc/testdata/test.db
--- a/vfs/mvcc/testdata/wal.db
+++ b/vfs/mvcc/testdata/wal.db
--- a/vfs/readervfs/reader.go
+++ b/vfs/readervfs/reader.go
@@ -3,14 +3,19 @@ package readervfs
 import (
 	"github.com/ncruces/go-sqlite3"
 	"github.com/ncruces/go-sqlite3/util/ioutil"
+	"github.com/ncruces/go-sqlite3/util/vfsutil"
 	"github.com/ncruces/go-sqlite3/vfs"
 )

 type readerVFS struct{}

 func (readerVFS) Open(name string, flags vfs.OpenFlag) (vfs.File, vfs.OpenFlag, error) {
+	// 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.
 	if flags&vfs.OPEN_MAIN_DB == 0 {
-		// notest
 		return nil, flags, sqlite3.CANTOPEN
 	}
 	readerMtx.RLock()
@@ -22,13 +27,13 @@ func (readerVFS) Open(name string, flags vfs.OpenFlag) (vfs.File, vfs.OpenFlag,
 }

 func (readerVFS) Delete(name string, dirSync bool) error {
-	// notest
+	// notest // IOCAP_IMMUTABLE
 	return sqlite3.IOERR_DELETE
 }

 func (readerVFS) Access(name string, flag vfs.AccessFlag) (bool, error) {
-	// notest
-	return false, nil
+	// notest // IOCAP_IMMUTABLE
+	return false, sqlite3.IOERR_ACCESS
 }

 func (readerVFS) FullPathname(name string) (string, error) {
@@ -42,37 +47,37 @@ func (readerFile) Close() error {
 }

 func (readerFile) WriteAt(b []byte, off int64) (n int, err error) {
-	// notest
-	return 0, sqlite3.READONLY
+	// notest // IOCAP_IMMUTABLE
+	return 0, sqlite3.IOERR_WRITE
 }

 func (readerFile) Truncate(size int64) error {
-	// notest
-	return sqlite3.READONLY
+	// notest // IOCAP_IMMUTABLE
+	return sqlite3.IOERR_TRUNCATE
 }

 func (readerFile) Sync(flag vfs.SyncFlag) error {
-	// notest
-	return nil
+	// notest // IOCAP_IMMUTABLE
+	return sqlite3.IOERR_FSYNC
 }

 func (readerFile) Lock(lock vfs.LockLevel) error {
-	// notest
-	return nil
+	// notest // IOCAP_IMMUTABLE
+	return sqlite3.IOERR_LOCK
 }

 func (readerFile) Unlock(lock vfs.LockLevel) error {
-	// notest
-	return nil
+	// notest // IOCAP_IMMUTABLE
+	return sqlite3.IOERR_UNLOCK
 }

 func (readerFile) CheckReservedLock() (bool, error) {
-	// notest
-	return false, nil
+	// notest // IOCAP_IMMUTABLE
+	return false, sqlite3.IOERR_CHECKRESERVEDLOCK
 }

 func (readerFile) SectorSize() int {
-	// notest
+	// notest // IOCAP_IMMUTABLE
 	return 0
 }

--- a/vfs/tests/mptest/mptest_test.go
+++ b/vfs/tests/mptest/mptest_test.go
@@ -24,6 +24,7 @@ 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"
 )

@@ -195,6 +196,50 @@ func Test_multiwrite01_memory(t *testing.T) {
 	mod.Close(ctx)
 }

+func Test_config01_mvcc(t *testing.T) {
+	mvcc.Create("test.db", "")
+	ctx := util.NewContext(newContext(t))
+	cfg := config(ctx).WithArgs("mptest", "/test.db", "config01.test",
+		"--vfs", "mvcc")
+	mod, err := rt.InstantiateModule(ctx, module, cfg)
+	if err != nil {
+		t.Fatal(err)
+	}
+	mod.Close(ctx)
+}
+
+func Test_crash01_mvcc(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping in short mode")
+	}
+
+	mvcc.Create("test.db", "")
+	ctx := util.NewContext(newContext(t))
+	cfg := config(ctx).WithArgs("mptest", "/test.db", "crash01.test",
+		"--vfs", "mvcc")
+	mod, err := rt.InstantiateModule(ctx, module, cfg)
+	if err != nil {
+		t.Fatal(err)
+	}
+	mod.Close(ctx)
+}
+
+func Test_multiwrite01_mvcc(t *testing.T) {
+	if testing.Short() && os.Getenv("CI") != "" {
+		t.Skip("skipping in slow CI")
+	}
+
+	mvcc.Create("test.db", "")
+	ctx := util.NewContext(newContext(t))
+	cfg := config(ctx).WithArgs("mptest", "/test.db", "multiwrite01.test",
+		"--vfs", "mvcc")
+	mod, err := rt.InstantiateModule(ctx, module, cfg)
+	if err != nil {
+		t.Fatal(err)
+	}
+	mod.Close(ctx)
+}
+
 func Test_crash01_wal(t *testing.T) {
 	if testing.Short() {
 		t.Skip("skipping in short mode")
--- a/vfs/tests/mptest/wasm/build.sh
+++ b/vfs/tests/mptest/wasm/build.sh
@@ -13,7 +13,8 @@ WASI_SDK="$ROOT/tools/wasi-sdk/bin"
 	-mmutable-globals -mnontrapping-fptoint \
 	-msimd128 -mbulk-memory -msign-ext \
 	-mreference-types -mmultivalue \
-	-fno-stack-protector -fno-stack-clash-protection \
+	-mno-extended-const \
+	-fno-stack-protector \
 	-Wl,--stack-first \
 	-Wl,--import-undefined \
 	-D_HAVE_SQLITE_CONFIG_H -DSQLITE_USE_URI \
@@ -25,9 +26,10 @@ WASI_SDK="$ROOT/tools/wasi-sdk/bin"
 	-D_WASI_EMULATED_GETPID -lwasi-emulated-getpid \
 	$(awk '{print "-Wl,--export="$0}' exports.txt)

-"$BINARYEN/wasm-opt" -g --strip --strip-producers -c -O3 \
-	mptest.wasm -o mptest.tmp --low-memory-unused \
+"$BINARYEN/wasm-opt" -g mptest.wasm -o mptest.tmp \
+	--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
 mv mptest.tmp mptest.wasm
--- a/vfs/tests/mptest/wasm/mptest.wasm
+++ b/vfs/tests/mptest/wasm/mptest.wasm
--- a/vfs/tests/speedtest1/speedtest1_test.go
+++ b/vfs/tests/speedtest1/speedtest1_test.go
@@ -21,6 +21,7 @@ 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"
 )

@@ -35,7 +36,7 @@ func TestMain(m *testing.M) {
 	initFlags()

 	ctx := context.Background()
-	cfg := wazero.NewRuntimeConfig().WithMemoryLimitPages(512)
+	cfg := wazero.NewRuntimeConfig().WithMemoryLimitPages(2048)
 	rt = wazero.NewRuntimeWithConfig(ctx, cfg)
 	wasi_snapshot_preview1.MustInstantiate(ctx, rt)
 	env := vfs.ExportHostFunctions(rt.NewHostModuleBuilder("env"))
--- a/vfs/tests/speedtest1/wasm/build.sh
+++ b/vfs/tests/speedtest1/wasm/build.sh
@@ -13,16 +13,18 @@ WASI_SDK="$ROOT/tools/wasi-sdk/bin"
 	-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 \
 	-D_HAVE_SQLITE_CONFIG_H -DSQLITE_USE_URI \
 	-DSQLITE_CUSTOM_INCLUDE=sqlite_opt.h \
 	$(awk '{print "-Wl,--export="$0}' exports.txt)

-"$BINARYEN/wasm-opt" -g --strip --strip-producers -c -O3 \
-	speedtest1.wasm -o speedtest1.tmp --low-memory-unused \
+"$BINARYEN/wasm-opt" -g speedtest1.wasm -o speedtest1.tmp \
+	--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
 mv speedtest1.tmp speedtest1.wasm
--- a/vfs/tests/speedtest1/wasm/speedtest1.wasm
+++ b/vfs/tests/speedtest1/wasm/speedtest1.wasm
--- a/vfs/vfs.go
+++ b/vfs/vfs.go
@@ -148,7 +148,7 @@ func vfsOpen(ctx context.Context, mod api.Module, pVfs, zPath, pFile ptr_t, flag
 	if pOutFlags != 0 {
 		util.Write32(mod, pOutFlags, flags)
 	}
-	file = cksmWrapFile(name, flags, file)
+	file = cksmWrapFile(file, flags)
 	vfsFileRegister(ctx, mod, pFile, file)
 	return _OK
 }
--- a/vfs/xts/xts.go
+++ b/vfs/xts/xts.go
@@ -19,7 +19,10 @@ type xtsVFS struct {

 func (x *xtsVFS) Open(name string, flags vfs.OpenFlag) (vfs.File, vfs.OpenFlag, error) {
 	// notest // OpenFilename is called instead
-	return nil, 0, sqlite3.CANTOPEN
+	if name == "" {
+		return x.OpenFilename(nil, flags)
+	}
+	return nil, flags, sqlite3.CANTOPEN
 }

 func (x *xtsVFS) OpenFilename(name *vfs.Filename, flags vfs.OpenFlag) (file vfs.File, _ vfs.OpenFlag, err error) {
@@ -124,10 +127,10 @@ func (x *xtsFile) ReadAt(p []byte, off int64) (n int, err error) {
 			return n, err
 		}

-		sectorNum := uint64(min / sectorSize)
-		x.cipher.Decrypt(x.sector[:], x.sector[:], sectorNum)
-
 		data := x.sector[:]
+		sectorNum := uint64(min / sectorSize)
+		x.cipher.Decrypt(data, x.sector[:], sectorNum)
+
 		if off > min {
 			data = data[off-min:]
 		}
@@ -150,16 +153,17 @@ func (x *xtsFile) WriteAt(p []byte, off int64) (n int, err error) {

 	// Write one block at a time.
 	for ; min < max; min += sectorSize {
-		sectorNum := uint64(min / sectorSize)
 		data := x.sector[:]
+		sectorNum := uint64(min / sectorSize)

 		if off > min || len(p[n:]) < sectorSize {
 			// Partial block write: read-update-write.
 			m, err := x.File.ReadAt(x.sector[:], min)
-			if m != sectorSize {
-				if err != io.EOF {
-					return n, err
-				}
+			if m == sectorSize {
+				x.cipher.Decrypt(data, x.sector[:], sectorNum)
+			} 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.
@@ -167,8 +171,6 @@ func (x *xtsFile) 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 {
-				x.cipher.Decrypt(data, data, sectorNum)
 			}
 			if off > min {
 				data = data[off-min:]
@@ -219,16 +221,16 @@ func (x *xtsFile) SizeHint(size int64) error {
 	return vfsutil.WrapSizeHint(x.File, roundUp(size))
 }

+// Wrap optional methods.
+
 func (x *xtsFile) Unwrap() vfs.File {
-	return x.File
+	return x.File // notest
 }

 func (x *xtsFile) SharedMemory() vfs.SharedMemory {
-	return vfsutil.WrapSharedMemory(x.File)
+	return vfsutil.WrapSharedMemory(x.File) // notest
 }

-// Wrap optional methods.
-
 func (x *xtsFile) LockState() vfs.LockLevel {
 	return vfsutil.WrapLockState(x.File) // notest
 }
Author	SHA1	Message	Date
Nuno Cruces	62f69011f1	Updated dependencies.	2025-09-08 13:59:41 +01:00
Nuno Cruces	4f9e3f900b	binaryen-version_124.	2025-09-08 12:23:58 +01:00
dependabot[bot]	4e90618350	Bump actions/setup-go from 5 to 6 (#318 ) 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>	2025-09-05 00:25:35 +02:00
Nuno Cruces	54bb94ce58	Improve WithMemoryCapacityFromMax (#317 ).	2025-09-03 09:03:59 +02:00
Nuno Cruces	07fec784e1	Grow memory geometrically. (#316 )	2025-09-01 12:57:33 +02:00
dependabot[bot]	da4638cbff	Bump actions/attest-build-provenance from 2 to 3 (#313 ) Bumps [actions/attest-build-provenance](https://github.com/actions/attest-build-provenance) from 2 to 3. - [Release notes](https://github.com/actions/attest-build-provenance/releases) - [Changelog](https://github.com/actions/attest-build-provenance/blob/main/RELEASE.md) - [Commits](https://github.com/actions/attest-build-provenance/compare/v2...v3) --- updated-dependencies: - dependency-name: actions/attest-build-provenance dependency-version: '3' 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>	2025-08-29 00:19:53 +02:00
dependabot[bot]	085872c2f3	Bump github.com/ncruces/aa from 0.3.1 to 0.3.2 (#311 ) Bumps [github.com/ncruces/aa](https://github.com/ncruces/aa) from 0.3.1 to 0.3.2. - [Commits](https://github.com/ncruces/aa/compare/v0.3.1...v0.3.2) --- updated-dependencies: - dependency-name: github.com/ncruces/aa dependency-version: 0.3.2 dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>	2025-08-26 17:20:13 +02:00
dependabot[bot]	de49aa2b06	Bump github.com/ncruces/aa from 0.3.0 to 0.3.1 (#310 ) Bumps [github.com/ncruces/aa](https://github.com/ncruces/aa) from 0.3.0 to 0.3.1. - [Commits](https://github.com/ncruces/aa/compare/v0.3.0...v0.3.1) --- updated-dependencies: - dependency-name: github.com/ncruces/aa dependency-version: 0.3.1 dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>	2025-08-23 05:21:11 +01:00
Nuno Cruces	1f3ad0165e	SQLite 3.50.4.	2025-08-21 19:05:44 +01:00
Nuno Cruces	0bda48d1d9	Gorm v1.30.1.	2025-08-21 18:56:05 +01:00
Nuno Cruces	0026bc91aa	MVCC memory VFS. (#309 )	2025-08-21 18:44:40 +01:00
Nuno Cruces	d84ca9d627	Fix #308 .	2025-08-16 19:45:10 +01:00
Nuno Cruces	5d14e01f94	Fix #304 .	2025-08-16 19:27:00 +01:00
Nuno Cruces	342df983d4	Fix #305 .	2025-08-14 23:46:48 +01:00
Nuno Cruces	00476fb1e2	Tests.	2025-08-14 15:04:10 +01:00
Nuno Cruces	8a64ee6eaa	Implement RowsColumnScanner.	2025-08-14 01:42:00 +01:00
Nuno Cruces	8f9a8e2752	Learnings from truffle.	2025-08-13 13:10:50 +01:00
Nuno Cruces	d8880e4cee	Fixes.	2025-08-13 03:34:21 +01:00
dependabot[bot]	4b154a842c	Bump actions/checkout from 4 to 5 (#303 ) Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 5. - [Release notes](https://github.com/actions/checkout/releases) - [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md) - [Commits](https://github.com/actions/checkout/compare/v4...v5) --- updated-dependencies: - dependency-name: actions/checkout dependency-version: '5' 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>	2025-08-12 08:47:41 +01:00
dependabot[bot]	758a53e9bf	Bump golang.org/x/crypto from 0.40.0 to 0.41.0 (#300 ) Bumps [golang.org/x/crypto](https://github.com/golang/crypto) from 0.40.0 to 0.41.0. - [Commits](https://github.com/golang/crypto/compare/v0.40.0...v0.41.0) --- updated-dependencies: - dependency-name: golang.org/x/crypto dependency-version: 0.41.0 dependency-type: direct:production update-type: version-update:semver-minor ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>	2025-08-08 00:30:25 +01:00
Nuno Cruces	1a42b4c590	Better fuzzing.	2025-08-07 16:27:45 +01:00
Nuno Cruces	7e4ec1df1c	Fix #299 .	2025-08-07 01:52:01 +01:00
Nuno Cruces	2c582a1d66	VFS improvements.	2025-08-05 14:15:21 +01:00
Nuno Cruces	20a67ca669	WAL mode serdes.	2025-08-02 11:48:37 +01:00
Nuno Cruces	789e2dc136	wasi-sdk-27.	2025-07-29 16:50:07 +01:00
Nuno Cruces	0399f10c06	VFS improvements.	2025-07-23 09:57:53 +01:00
Nuno Cruces	75c6744b5b	FreeBSD 14.3.	2025-07-22 23:47:22 +01:00
Nuno Cruces	754e806164	Tests.	2025-07-22 10:34:30 +01:00
Nuno Cruces	2640c9fb54	SQLite 3.50.3.	2025-07-17 19:42:01 +01:00