Refactor file handles.

internal/util/handle.go

@@ -0,0 +1,60 @@
+package util
+
+import (
+	"context"
+	"io"
+)
+
+type handleKey struct{}
+type handleState struct {
+	handles []any
+}
+
+func NewContext(ctx context.Context) (context.Context, io.Closer) {
+	state := new(handleState)
+	return context.WithValue(ctx, handleKey{}, state), state
+}
+
+func (s *handleState) Close() (err error) {
+	for _, h := range s.handles {
+		if c, ok := h.(io.Closer); ok {
+			if e := c.Close(); err == nil {
+				err = e
+			}
+		}
+	}
+	s.handles = nil
+	return err
+}
+
+func GetHandle(ctx context.Context, id uint32) any {
+	s := ctx.Value(handleKey{}).(*handleState)
+	return s.handles[id]
+}
+
+func DelHandle(ctx context.Context, id uint32) error {
+	s := ctx.Value(handleKey{}).(*handleState)
+	a := s.handles[id]
+	s.handles[id] = nil
+	if c, ok := a.(io.Closer); ok {
+		return c.Close()
+	}
+	return nil
+
+}
+
+func AddHandle(ctx context.Context, a any) (id uint32) {
+	s := ctx.Value(handleKey{}).(*handleState)
+
+	// Find an empty slot.
+	for id, h := range s.handles {
+		if h == nil {
+			s.handles[id] = a
+			return uint32(id)
+		}
+	}
+
+	// Add a new slot.
+	s.handles = append(s.handles, a)
+	return uint32(len(s.handles) - 1)
+}

module.go

@@ -77,17 +77,17 @@ func compileModule() {
 }
 
 type module struct {
-	ctx context.Context
-	mod api.Module
-	vfs io.Closer
-	api sqliteAPI
-	arg [8]uint64
+	ctx    context.Context
+	mod    api.Module
+	closer io.Closer
+	api    sqliteAPI
+	stack  [8]uint64
 }
 
 func newModule(mod api.Module) (m *module, err error) {
 	m = new(module)
 	m.mod = mod
-	m.ctx, m.vfs = vfs.NewContext(context.Background())
+	m.ctx, m.closer = util.NewContext(context.Background())
 
 	getFun := func(name string) api.Function {
 		f := mod.ExportedFunction(name)
@@ -164,7 +164,7 @@ func newModule(mod api.Module) (m *module, err error) {
 
 func (m *module) close() error {
 	err := m.mod.Close(m.ctx)
-	m.vfs.Close()
+	m.closer.Close()
 	return err
 }
 
@@ -201,14 +201,14 @@ func (m *module) error(rc uint64, handle uint32, sql ...string) error {
 }
 
 func (m *module) call(fn api.Function, params ...uint64) uint64 {
-	copy(m.arg[:], params)
-	err := fn.CallWithStack(m.ctx, m.arg[:])
+	copy(m.stack[:], params)
+	err := fn.CallWithStack(m.ctx, m.stack[:])
 	if err != nil {
 		// The module closed or panicked; release resources.
-		m.vfs.Close()
+		m.closer.Close()
 		panic(err)
 	}
-	return m.arg[0]
+	return m.stack[0]
 }
 
 func (m *module) free(ptr uint32) {

vfs/lock_test.go

@@ -41,8 +41,8 @@ func Test_vfsLock(t *testing.T) {
 		pOutput = 32
 	)
 	mod := wazerotest.NewModule(wazerotest.NewMemory(wazerotest.PageSize))
-	ctx, vfs := NewContext(context.TODO())
-	defer vfs.Close()
+	ctx, closer := util.NewContext(context.TODO())
+	defer closer.Close()
 
 	vfsFileRegister(ctx, mod, pFile1, &vfsFile{File: file1})
 	vfsFileRegister(ctx, mod, pFile2, &vfsFile{File: file2})

vfs/tests/mptest/mptest_test.go

@@ -16,6 +16,7 @@ import (
 	"sync/atomic"
 	"testing"
 
+	"github.com/ncruces/go-sqlite3/internal/util"
 	"github.com/ncruces/go-sqlite3/vfs"
 	_ "github.com/ncruces/go-sqlite3/vfs/memdb"
 	"github.com/tetratelabs/wazero"
@@ -82,16 +83,16 @@ func system(ctx context.Context, mod api.Module, ptr uint32) uint32 {
 
 	cfg := config(ctx).WithArgs(args...)
 	go func() {
-		ctx, vfs := vfs.NewContext(ctx)
+		ctx, closer := util.NewContext(ctx)
 		mod, _ := rt.InstantiateModule(ctx, module, cfg)
 		mod.Close(ctx)
-		vfs.Close()
+		closer.Close()
 	}()
 	return 0
 }
 
 func Test_config01(t *testing.T) {
-	ctx, vfs := vfs.NewContext(newContext(t))
+	ctx, closer := util.NewContext(newContext(t))
 	name := filepath.Join(t.TempDir(), "test.db")
 	cfg := config(ctx).WithArgs("mptest", name, "config01.test")
 	mod, err := rt.InstantiateModule(ctx, module, cfg)
@@ -99,7 +100,7 @@ func Test_config01(t *testing.T) {
 		t.Error(err)
 	}
 	mod.Close(ctx)
-	vfs.Close()
+	closer.Close()
 }
 
 func Test_config02(t *testing.T) {
@@ -110,7 +111,7 @@ func Test_config02(t *testing.T) {
 		t.Skip("skipping in CI")
 	}
 
-	ctx, vfs := vfs.NewContext(newContext(t))
+	ctx, closer := util.NewContext(newContext(t))
 	name := filepath.Join(t.TempDir(), "test.db")
 	cfg := config(ctx).WithArgs("mptest", name, "config02.test")
 	mod, err := rt.InstantiateModule(ctx, module, cfg)
@@ -118,7 +119,7 @@ func Test_config02(t *testing.T) {
 		t.Error(err)
 	}
 	mod.Close(ctx)
-	vfs.Close()
+	closer.Close()
 }
 
 func Test_crash01(t *testing.T) {
@@ -126,7 +127,7 @@ func Test_crash01(t *testing.T) {
 		t.Skip("skipping in short mode")
 	}
 
-	ctx, vfs := vfs.NewContext(newContext(t))
+	ctx, closer := util.NewContext(newContext(t))
 	name := filepath.Join(t.TempDir(), "test.db")
 	cfg := config(ctx).WithArgs("mptest", name, "crash01.test")
 	mod, err := rt.InstantiateModule(ctx, module, cfg)
@@ -134,7 +135,7 @@ func Test_crash01(t *testing.T) {
 		t.Error(err)
 	}
 	mod.Close(ctx)
-	vfs.Close()
+	closer.Close()
 }
 
 func Test_multiwrite01(t *testing.T) {
@@ -142,7 +143,7 @@ func Test_multiwrite01(t *testing.T) {
 		t.Skip("skipping in short mode")
 	}
 
-	ctx, vfs := vfs.NewContext(newContext(t))
+	ctx, closer := util.NewContext(newContext(t))
 	name := filepath.Join(t.TempDir(), "test.db")
 	cfg := config(ctx).WithArgs("mptest", name, "multiwrite01.test")
 	mod, err := rt.InstantiateModule(ctx, module, cfg)
@@ -150,11 +151,11 @@ func Test_multiwrite01(t *testing.T) {
 		t.Error(err)
 	}
 	mod.Close(ctx)
-	vfs.Close()
+	closer.Close()
 }
 
 func Test_config01_memory(t *testing.T) {
-	ctx, vfs := vfs.NewContext(newContext(t))
+	ctx, closer := util.NewContext(newContext(t))
 	cfg := config(ctx).WithArgs("mptest", "test.db",
 		"config01.test",
 		"--vfs", "memdb",
@@ -164,7 +165,7 @@ func Test_config01_memory(t *testing.T) {
 		t.Error(err)
 	}
 	mod.Close(ctx)
-	vfs.Close()
+	closer.Close()
 }
 
 func Test_multiwrite01_memory(t *testing.T) {
@@ -172,7 +173,7 @@ func Test_multiwrite01_memory(t *testing.T) {
 		t.Skip("skipping in short mode")
 	}
 
-	ctx, vfs := vfs.NewContext(newContext(t))
+	ctx, closer := util.NewContext(newContext(t))
 	cfg := config(ctx).WithArgs("mptest", "/test.db",
 		"multiwrite01.test",
 		"--vfs", "memdb",
@@ -182,7 +183,7 @@ func Test_multiwrite01_memory(t *testing.T) {
 		t.Error(err)
 	}
 	mod.Close(ctx)
-	vfs.Close()
+	closer.Close()
 }
 
 func newContext(t *testing.T) context.Context {

vfs/tests/speedtest1/speedtest1_test.go

@@ -18,6 +18,7 @@ import (
 	"github.com/tetratelabs/wazero"
 	"github.com/tetratelabs/wazero/imports/wasi_snapshot_preview1"
 
+	"github.com/ncruces/go-sqlite3/internal/util"
 	"github.com/ncruces/go-sqlite3/vfs"
 	_ "github.com/ncruces/go-sqlite3/vfs/memdb"
 )
@@ -74,7 +75,7 @@ func initFlags() {
 
 func Benchmark_speedtest1(b *testing.B) {
 	output.Reset()
-	ctx, vfs := vfs.NewContext(context.Background())
+	ctx, closer := util.NewContext(context.Background())
 	name := filepath.Join(b.TempDir(), "test.db")
 	args := append(options, "--size", strconv.Itoa(b.N), name)
 	cfg := wazero.NewModuleConfig().
@@ -88,5 +89,5 @@ func Benchmark_speedtest1(b *testing.B) {
 		b.Error(err)
 	}
 	mod.Close(ctx)
-	vfs.Close()
+	closer.Close()
 }

vfs/vfs.go

@@ -44,33 +44,6 @@ func ExportHostFunctions(env wazero.HostModuleBuilder) wazero.HostModuleBuilder
 	return env
 }
 
-type vfsKey struct{}
-type vfsState struct {
-	files []File
-}
-
-// NewContext is an internal API users need not call directly.
-//
-// NewContext creates a new context to hold [api.Module] specific VFS data.
-// The context should be passed to any [api.Function] calls that might
-// generate VFS host callbacks.
-// The returned [io.Closer] should be closed after the [api.Module] is closed,
-// to release any associated resources.
-func NewContext(ctx context.Context) (context.Context, io.Closer) {
-	vfs := new(vfsState)
-	return context.WithValue(ctx, vfsKey{}, vfs), vfs
-}
-
-func (vfs *vfsState) Close() error {
-	for _, f := range vfs.files {
-		if f != nil {
-			f.Close()
-		}
-	}
-	vfs.files = nil
-	return nil
-}
-
 func vfsFind(ctx context.Context, mod api.Module, zVfsName uint32) uint32 {
 	name := util.ReadString(mod, zVfsName, _MAX_STRING)
 	if vfs := Find(name); vfs != nil && vfs != (vfsOS{}) {
@@ -431,40 +404,22 @@ func vfsGet(mod api.Module, pVfs uint32) VFS {
 	panic(util.NoVFSErr + util.ErrorString(name))
 }
 
-func vfsFileNew(vfs *vfsState, file File) uint32 {
-	// Find an empty slot.
-	for id, f := range vfs.files {
-		if f == nil {
-			vfs.files[id] = file
-			return uint32(id)
-		}
-	}
-
-	// Add a new slot.
-	vfs.files = append(vfs.files, file)
-	return uint32(len(vfs.files) - 1)
-}
-
 func vfsFileRegister(ctx context.Context, mod api.Module, pFile uint32, file File) {
 	const fileHandleOffset = 4
-	id := vfsFileNew(ctx.Value(vfsKey{}).(*vfsState), file)
+	id := util.AddHandle(ctx, file)
 	util.WriteUint32(mod, pFile+fileHandleOffset, id)
 }
 
 func vfsFileGet(ctx context.Context, mod api.Module, pFile uint32) File {
 	const fileHandleOffset = 4
-	vfs := ctx.Value(vfsKey{}).(*vfsState)
 	id := util.ReadUint32(mod, pFile+fileHandleOffset)
-	return vfs.files[id]
+	return util.GetHandle(ctx, id).(File)
 }
 
 func vfsFileClose(ctx context.Context, mod api.Module, pFile uint32) error {
 	const fileHandleOffset = 4
-	vfs := ctx.Value(vfsKey{}).(*vfsState)
 	id := util.ReadUint32(mod, pFile+fileHandleOffset)
-	file := vfs.files[id]
-	vfs.files[id] = nil
-	return file.Close()
+	return util.DelHandle(ctx, id)
 }
 
 func vfsErrorCode(err error, def _ErrorCode) _ErrorCode {

vfs/vfs_test.go

@@ -220,8 +220,8 @@ func Test_vfsAccess(t *testing.T) {
 
 func Test_vfsFile(t *testing.T) {
 	mod := wazerotest.NewModule(wazerotest.NewMemory(wazerotest.PageSize))
-	ctx, vfs := NewContext(context.TODO())
-	defer vfs.Close()
+	ctx, closer := util.NewContext(context.TODO())
+	defer closer.Close()
 
 	// Open a temporary file.
 	rc := vfsOpen(ctx, mod, 0, 0, 4, OPEN_CREATE|OPEN_EXCLUSIVE|OPEN_READWRITE|OPEN_DELETEONCLOSE, 0)
@@ -293,8 +293,8 @@ func Test_vfsFile(t *testing.T) {
 
 func Test_vfsFile_psow(t *testing.T) {
 	mod := wazerotest.NewModule(wazerotest.NewMemory(wazerotest.PageSize))
-	ctx, vfs := NewContext(context.TODO())
-	defer vfs.Close()
+	ctx, closer := util.NewContext(context.TODO())
+	defer closer.Close()
 
 	// Open a temporary file.
 	rc := vfsOpen(ctx, mod, 0, 0, 4, OPEN_CREATE|OPEN_EXCLUSIVE|OPEN_READWRITE|OPEN_DELETEONCLOSE, 0)