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Virtual tables fixes.
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@ncruces
ncruces committed Nov 20, 2023
1 parent 5992403 commit ae1d696
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Showing 5 changed files with 108 additions and 85 deletions.
8 changes: 4 additions & 4 deletions blob.go
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Original file line number Diff line number Diff line change
Expand Up @@ -92,8 +92,8 @@ func (b *Blob) Read(p []byte) (n int, err error) {
want = avail
}

defer b.c.arena.reset()
ptr := b.c.arena.new(uint64(want))
ptr := b.c.new(uint64(want))
defer b.c.free(ptr)

r := b.c.call(b.c.api.blobRead, uint64(b.handle),
uint64(ptr), uint64(want), uint64(b.offset))
Expand Down Expand Up @@ -158,8 +158,8 @@ func (b *Blob) WriteTo(w io.Writer) (n int64, err error) {
//
// https://sqlite.org/c3ref/blob_write.html
func (b *Blob) Write(p []byte) (n int, err error) {
defer b.c.arena.reset()
ptr := b.c.arena.bytes(p)
ptr := b.c.newBytes(p)
defer b.c.free(ptr)

r := b.c.call(b.c.api.blobWrite, uint64(b.handle),
uint64(ptr), uint64(len(p)), uint64(b.offset))
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2 changes: 2 additions & 0 deletions sqlite.go
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Original file line number Diff line number Diff line change
Expand Up @@ -185,6 +185,7 @@ func instantiateSQLite() (sqlt *sqlite, err error) {
resultErrorBig: getFun("sqlite3_result_error_toobig"),
createModule: getFun("sqlite3_create_module_go"),
declareVTab: getFun("sqlite3_declare_vtab"),
vtabRHSValue: getFun("sqlite3_vtab_rhs_value"),
}
if err != nil {
return nil, err
Expand Down Expand Up @@ -411,6 +412,7 @@ type sqliteAPI struct {
resultErrorBig api.Function
createModule api.Function
declareVTab api.Function
vtabRHSValue api.Function
destructor uint32
}

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1 change: 1 addition & 0 deletions stmt.go
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Original file line number Diff line number Diff line change
Expand Up @@ -266,6 +266,7 @@ func (s *Stmt) bindRFC3339Nano(param int, value time.Time) error {
// BindPointer binds a NULL to the prepared statement, just like [Stmt.BindNull],
// but it also associates ptr with that NULL value such that it can be retrieved
// within an application-defined SQL function using [Value.Pointer].
// The leftmost SQL parameter has an index of 1.
//
// https://sqlite.org/c3ref/bind_blob.html
func (s *Stmt) BindPointer(param int, ptr any) error {
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109 changes: 70 additions & 39 deletions vtab.go
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Original file line number Diff line number Diff line change
Expand Up @@ -66,7 +66,7 @@ func implements[T any](typ reflect.Type) bool {
}

func (c *Conn) DeclareVtab(sql string) error {
defer c.arena.reset()
// defer c.arena.reset()
sqlPtr := c.arena.string(sql)
r := c.call(c.api.declareVTab, uint64(c.handle), uint64(sqlPtr))
return c.error(r)
Expand Down Expand Up @@ -193,18 +193,21 @@ type VTabCursor interface {
//
// https://sqlite.org/c3ref/index_info.html
type IndexInfo struct {
/* Inputs */
Constraint []IndexConstraint
OrderBy []IndexOrderBy
/* Outputs */
// Inputs
Constraint []IndexConstraint
OrderBy []IndexOrderBy
ColumnsUsed int64
// Outputs
ConstraintUsage []IndexConstraintUsage
IdxNum int
IdxStr string
IdxFlags IndexScanFlag
OrderByConsumed bool
EstimatedCost float64
EstimatedRows int64
ColumnsUsed int64
// Internal
c *Conn
handle uint32
}

// An IndexConstraint describes virtual table indexing constraint information.
Expand Down Expand Up @@ -232,8 +235,28 @@ type IndexConstraintUsage struct {
Omit bool
}

func (idx *IndexInfo) load(ctx context.Context, mod api.Module, ptr uint32) {
// RHSValue returns the value of the right-hand operand of a constraint
// if the right-hand operand is known.
//
// https://sqlite.org/c3ref/vtab_rhs_value.html
func (idx *IndexInfo) RHSValue(column int) (*Value, error) {
// defer idx.c.arena.reset()
valPtr := idx.c.arena.new(ptrlen)
r := idx.c.call(idx.c.api.vtabRHSValue,
uint64(idx.handle), uint64(column), uint64(valPtr))
if err := idx.c.error(r); err != nil {
return nil, err
}
return &Value{
sqlite: idx.c.sqlite,
handle: util.ReadUint32(idx.c.mod, valPtr),
}, nil
}

func (idx *IndexInfo) load() {
// https://sqlite.org/c3ref/index_info.html
mod := idx.c.mod
ptr := idx.handle

idx.Constraint = make([]IndexConstraint, util.ReadUint32(mod, ptr+0))
idx.ConstraintUsage = make([]IndexConstraintUsage, util.ReadUint32(mod, ptr+0))
Expand All @@ -242,25 +265,31 @@ func (idx *IndexInfo) load(ctx context.Context, mod api.Module, ptr uint32) {
constraintPtr := util.ReadUint32(mod, ptr+4)
for i := range idx.Constraint {
idx.Constraint[i] = IndexConstraint{
Column: int(util.ReadUint32(mod, constraintPtr+0)),
Column: int(int32(util.ReadUint32(mod, constraintPtr+0))),
Op: IndexConstraintOp(util.ReadUint8(mod, constraintPtr+4)),
Usable: util.ReadUint8(mod, constraintPtr+8) != 0,
Usable: util.ReadUint8(mod, constraintPtr+5) != 0,
}
constraintPtr += 12
}

orderByPtr := util.ReadUint32(mod, ptr+12)
for i := range idx.OrderBy {
idx.OrderBy[i] = IndexOrderBy{
Column: int(util.ReadUint32(mod, orderByPtr+0)),
Column: int(int32(util.ReadUint32(mod, orderByPtr+0))),
Desc: util.ReadUint8(mod, orderByPtr+4) != 0,
}
orderByPtr += 8
}

idx.EstimatedCost = util.ReadFloat64(mod, ptr+40)
idx.EstimatedRows = int64(util.ReadUint64(mod, ptr+48))
idx.ColumnsUsed = int64(util.ReadUint64(mod, ptr+64))
}

func (idx *IndexInfo) save(ctx context.Context, mod api.Module, ptr uint32) {
func (idx *IndexInfo) save() {
// https://sqlite.org/c3ref/index_info.html
mod := idx.c.mod
ptr := idx.handle

usagePtr := util.ReadUint32(mod, ptr+16)
for _, usage := range idx.ConstraintUsage {
Expand All @@ -273,8 +302,7 @@ func (idx *IndexInfo) save(ctx context.Context, mod api.Module, ptr uint32) {

util.WriteUint32(mod, ptr+20, uint32(idx.IdxNum))
if idx.IdxStr != "" {
db := ctx.Value(connKey{}).(*Conn)
util.WriteUint32(mod, ptr+24, db.newString(idx.IdxStr))
util.WriteUint32(mod, ptr+24, idx.c.newString(idx.IdxStr))
util.WriteUint32(mod, ptr+28, 1)
}
if idx.OrderByConsumed {
Expand All @@ -283,7 +311,6 @@ func (idx *IndexInfo) save(ctx context.Context, mod api.Module, ptr uint32) {
util.WriteFloat64(mod, ptr+40, idx.EstimatedCost)
util.WriteUint64(mod, ptr+48, uint64(idx.EstimatedRows))
util.WriteUint32(mod, ptr+56, uint32(idx.IdxFlags))
util.WriteUint64(mod, ptr+64, uint64(idx.ColumnsUsed))
}

// IndexConstraintOp is a virtual table constraint operator code.
Expand All @@ -292,23 +319,23 @@ func (idx *IndexInfo) save(ctx context.Context, mod api.Module, ptr uint32) {
type IndexConstraintOp uint8

const (
Eq IndexConstraintOp = 2
Gt IndexConstraintOp = 4
Le IndexConstraintOp = 8
Lt IndexConstraintOp = 16
Ge IndexConstraintOp = 32
Match IndexConstraintOp = 64
Like IndexConstraintOp = 65 /* 3.10.0 and later */
Glob IndexConstraintOp = 66 /* 3.10.0 and later */
Regexp IndexConstraintOp = 67 /* 3.10.0 and later */
Ne IndexConstraintOp = 68 /* 3.21.0 and later */
IsNot IndexConstraintOp = 69 /* 3.21.0 and later */
IsNotNull IndexConstraintOp = 70 /* 3.21.0 and later */
IsNull IndexConstraintOp = 71 /* 3.21.0 and later */
Is IndexConstraintOp = 72 /* 3.21.0 and later */
Limit IndexConstraintOp = 73 /* 3.38.0 and later */
Offset IndexConstraintOp = 74 /* 3.38.0 and later */
Function IndexConstraintOp = 150 /* 3.25.0 and later */
INDEX_CONSTRAINT_EQ IndexConstraintOp = 2
INDEX_CONSTRAINT_GT IndexConstraintOp = 4
INDEX_CONSTRAINT_LE IndexConstraintOp = 8
INDEX_CONSTRAINT_LT IndexConstraintOp = 16
INDEX_CONSTRAINT_GE IndexConstraintOp = 32
INDEX_CONSTRAINT_MATCH IndexConstraintOp = 64
INDEX_CONSTRAINT_LIKE IndexConstraintOp = 65
INDEX_CONSTRAINT_GLOB IndexConstraintOp = 66
INDEX_CONSTRAINT_REGEXP IndexConstraintOp = 67
INDEX_CONSTRAINT_NE IndexConstraintOp = 68
INDEX_CONSTRAINT_ISNOT IndexConstraintOp = 69
INDEX_CONSTRAINT_ISNOTNULL IndexConstraintOp = 70
INDEX_CONSTRAINT_ISNULL IndexConstraintOp = 71
INDEX_CONSTRAINT_IS IndexConstraintOp = 72
INDEX_CONSTRAINT_LIMIT IndexConstraintOp = 73
INDEX_CONSTRAINT_OFFSET IndexConstraintOp = 74
INDEX_CONSTRAINT_FUNCTION IndexConstraintOp = 150
)

// IndexScanFlag is a virtual table scan flag.
Expand All @@ -317,22 +344,20 @@ const (
type IndexScanFlag uint32

const (
Unique IndexScanFlag = 1
INDEX_SCAN_UNIQUE IndexScanFlag = 1
)

func vtabReflectCallback(name string) func(_ context.Context, _ api.Module, _, _, _, _, _ uint32) uint32 {
return func(ctx context.Context, mod api.Module, pMod, argc, argv, ppVTab, pzErr uint32) uint32 {
module := vtabGetHandle(ctx, mod, pMod)
db := ctx.Value(connKey{}).(*Conn)

arg := make([]reflect.Value, 1+argc)
arg[0] = reflect.ValueOf(db)
arg[0] = reflect.ValueOf(ctx.Value(connKey{}))

for i := uint32(0); i < argc; i++ {
ptr := util.ReadUint32(mod, argv+i*ptrlen)
arg[i+1] = reflect.ValueOf(util.ReadString(mod, ptr, _MAX_STRING))
}

module := vtabGetHandle(ctx, mod, pMod)
res := reflect.ValueOf(module).MethodByName(name).Call(arg)
err, _ := res[1].Interface().(error)
if err == nil {
Expand All @@ -359,12 +384,14 @@ func vtabDestroyCallback(ctx context.Context, mod api.Module, pVTab uint32) uint

func vtabBestIndexCallback(ctx context.Context, mod api.Module, pVTab, pIdxInfo uint32) uint32 {
var info IndexInfo
info.load(ctx, mod, pIdxInfo)
info.handle = pIdxInfo
info.c = ctx.Value(connKey{}).(*Conn)
info.load()

vtab := vtabGetHandle(ctx, mod, pVTab).(VTab)
err := vtab.BestIndex(&info)

info.save(ctx, mod, pIdxInfo)
info.save()
return vtabError(ctx, mod, pVTab, _VTAB_ERROR, err)
}

Expand Down Expand Up @@ -473,7 +500,11 @@ func cursorFilterCallback(ctx context.Context, mod api.Module, pCur, idxNum, idx
cursor := vtabGetHandle(ctx, mod, pCur).(VTabCursor)
db := ctx.Value(connKey{}).(*Conn)
args := callbackArgs(db, argc, argv)
err := cursor.Filter(int(idxNum), util.ReadString(mod, idxStr, _MAX_STRING), args...)
var idxName string
if idxStr != 0 {
idxName = util.ReadString(mod, idxStr, _MAX_STRING)
}
err := cursor.Filter(int(idxNum), idxName, args...)
return vtabError(ctx, mod, pCur, _CURSOR_ERROR, err)
}

Expand Down
73 changes: 31 additions & 42 deletions vtab_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -15,7 +15,7 @@ func ExampleCreateModule() {
}
defer db.Close()

err = sqlite3.CreateModule(db, "generate_series", seriesModule{})
err = sqlite3.CreateModule(db, "generate_series", seriesTable{})
if err != nil {
log.Fatal(err)
}
Expand All @@ -38,68 +38,57 @@ func ExampleCreateModule() {
// 8 8
}

type seriesModule struct{}
type seriesTable struct{}

func (seriesModule) Connect(c *sqlite3.Conn, arg ...string) (*seriesTable, error) {
err := c.DeclareVtab(`CREATE TABLE x(value, start HIDDEN, stop HIDDEN, step HIDDEN)`)
if err != nil {
return nil, err
}
return &seriesTable{0, 0, 1}, nil
}

type seriesTable struct {
start int64
stop int64
step int64
func (seriesTable) Connect(c *sqlite3.Conn, arg ...string) (_ seriesTable, err error) {
err = c.DeclareVtab(`CREATE TABLE x(value, start HIDDEN, stop HIDDEN, step HIDDEN)`)
return
}

func (*seriesTable) Disconnect() error {
func (seriesTable) Disconnect() error {
return nil
}

func (*seriesTable) BestIndex(idx *sqlite3.IndexInfo) error {
idx.IdxNum = 0
idx.IdxStr = "default"
argv := 1
func (seriesTable) BestIndex(idx *sqlite3.IndexInfo) error {
for i, cst := range idx.Constraint {
if cst.Op == sqlite3.Eq {
idx.ConstraintUsage[i] = sqlite3.IndexConstraintUsage{
ArgvIndex: argv,
Omit: true,
switch cst.Column {
case 1, 2, 3: // start, stop, step
if cst.Op == sqlite3.INDEX_CONSTRAINT_EQ && cst.Usable {
idx.ConstraintUsage[i] = sqlite3.IndexConstraintUsage{
ArgvIndex: cst.Column,
Omit: true,
}
}
argv++
}
}
return nil
}

func (tab *seriesTable) Open() (sqlite3.VTabCursor, error) {
return &seriesCursor{tab, 0}, nil
func (seriesTable) Open() (sqlite3.VTabCursor, error) {
return &seriesCursor{}, nil
}

type seriesCursor struct {
*seriesTable
start int64
stop int64
step int64
value int64
}

func (cur *seriesCursor) Filter(idxNum int, idxStr string, arg ...sqlite3.Value) error {
switch len(arg) {
case 0:
cur.seriesTable.start = 0
cur.seriesTable.stop = 1000
case 1:
cur.seriesTable.start = arg[0].Int64()
cur.seriesTable.stop = 1000
case 2:
cur.seriesTable.start = arg[0].Int64()
cur.seriesTable.stop = arg[1].Int64()
case 3:
cur.seriesTable.start = arg[0].Int64()
cur.seriesTable.stop = arg[1].Int64()
cur.seriesTable.step = arg[2].Int64()
cur.start = 0
cur.stop = 1000
cur.step = 1
if len(arg) > 0 {
cur.start = arg[0].Int64()
}
if len(arg) > 1 {
cur.stop = arg[1].Int64()
}
if len(arg) > 2 {
cur.step = arg[2].Int64()
}
cur.value = cur.seriesTable.start
cur.value = cur.start
return nil
}

Expand Down

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