update go-sqlite3 => v0.20.0 (#3483)

vendor/github.com/ncruces/go-sqlite3/util/sql3util/parse.go

@@ -0,0 +1,210 @@
+package sql3util
+
+import (
+	"context"
+	_ "embed"
+	"sync"
+
+	"github.com/tetratelabs/wazero"
+	"github.com/tetratelabs/wazero/api"
+
+	"github.com/ncruces/go-sqlite3/internal/util"
+)
+
+const (
+	errp = 4
+	sqlp = 8
+)
+
+var (
+	//go:embed parse/sql3parse_table.wasm
+	binary   []byte
+	once     sync.Once
+	runtime  wazero.Runtime
+	compiled wazero.CompiledModule
+)
+
+// ParseTable parses a [CREATE] or [ALTER TABLE] command.
+//
+// [CREATE]: https://sqlite.org/lang_createtable.html
+// [ALTER TABLE]: https://sqlite.org/lang_altertable.html
+func ParseTable(sql string) (_ *Table, err error) {
+	once.Do(func() {
+		ctx := context.Background()
+		cfg := wazero.NewRuntimeConfigInterpreter()
+		runtime = wazero.NewRuntimeWithConfig(ctx, cfg)
+		compiled, err = runtime.CompileModule(ctx, binary)
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	ctx := context.Background()
+	mod, err := runtime.InstantiateModule(ctx, compiled, wazero.NewModuleConfig().WithName(""))
+	if err != nil {
+		return nil, err
+	}
+	defer mod.Close(ctx)
+
+	if buf, ok := mod.Memory().Read(sqlp, uint32(len(sql))); ok {
+		copy(buf, sql)
+	}
+
+	stack := [...]uint64{sqlp, uint64(len(sql)), errp}
+	err = mod.ExportedFunction("sql3parse_table").CallWithStack(ctx, stack[:])
+	if err != nil {
+		return nil, err
+	}
+
+	c, _ := mod.Memory().ReadUint32Le(errp)
+	switch c {
+	case _MEMORY:
+		panic(util.OOMErr)
+	case _SYNTAX:
+		return nil, util.ErrorString("sql3parse: invalid syntax")
+	case _UNSUPPORTEDSQL:
+		return nil, util.ErrorString("sql3parse: unsupported SQL")
+	}
+
+	var tab Table
+	tab.load(mod, uint32(stack[0]), sql)
+	return &tab, nil
+}
+
+// Table holds metadata about a table.
+type Table struct {
+	Name           string
+	Schema         string
+	Comment        string
+	IsTemporary    bool
+	IsIfNotExists  bool
+	IsWithoutRowID bool
+	IsStrict       bool
+	Columns        []Column
+	Type           StatementType
+	CurrentName    string
+	NewName        string
+}
+
+func (t *Table) load(mod api.Module, ptr uint32, sql string) {
+	t.Name = loadString(mod, ptr+0, sql)
+	t.Schema = loadString(mod, ptr+8, sql)
+	t.Comment = loadString(mod, ptr+16, sql)
+
+	t.IsTemporary = loadBool(mod, ptr+24)
+	t.IsIfNotExists = loadBool(mod, ptr+25)
+	t.IsWithoutRowID = loadBool(mod, ptr+26)
+	t.IsStrict = loadBool(mod, ptr+27)
+
+	t.Columns = loadSlice(mod, ptr+28, func(ptr uint32, res *Column) {
+		p, _ := mod.Memory().ReadUint32Le(ptr)
+		res.load(mod, p, sql)
+	})
+
+	t.Type = loadEnum[StatementType](mod, ptr+44)
+	t.CurrentName = loadString(mod, ptr+48, sql)
+	t.NewName = loadString(mod, ptr+56, sql)
+}
+
+// Column holds metadata about a column.
+type Column struct {
+	Name                  string
+	Type                  string
+	Length                string
+	ConstraintName        string
+	Comment               string
+	IsPrimaryKey          bool
+	IsAutoIncrement       bool
+	IsNotNull             bool
+	IsUnique              bool
+	PKOrder               OrderClause
+	PKConflictClause      ConflictClause
+	NotNullConflictClause ConflictClause
+	UniqueConflictClause  ConflictClause
+	CheckExpr             string
+	DefaultExpr           string
+	CollateName           string
+	ForeignKeyClause      *ForeignKey
+}
+
+func (c *Column) load(mod api.Module, ptr uint32, sql string) {
+	c.Name = loadString(mod, ptr+0, sql)
+	c.Type = loadString(mod, ptr+8, sql)
+	c.Length = loadString(mod, ptr+16, sql)
+	c.ConstraintName = loadString(mod, ptr+24, sql)
+	c.Comment = loadString(mod, ptr+32, sql)
+
+	c.IsPrimaryKey = loadBool(mod, ptr+40)
+	c.IsAutoIncrement = loadBool(mod, ptr+41)
+	c.IsNotNull = loadBool(mod, ptr+42)
+	c.IsUnique = loadBool(mod, ptr+43)
+
+	c.PKOrder = loadEnum[OrderClause](mod, ptr+44)
+	c.PKConflictClause = loadEnum[ConflictClause](mod, ptr+48)
+	c.NotNullConflictClause = loadEnum[ConflictClause](mod, ptr+52)
+	c.UniqueConflictClause = loadEnum[ConflictClause](mod, ptr+56)
+
+	c.CheckExpr = loadString(mod, ptr+60, sql)
+	c.DefaultExpr = loadString(mod, ptr+68, sql)
+	c.CollateName = loadString(mod, ptr+76, sql)
+
+	if ptr, _ := mod.Memory().ReadUint32Le(ptr + 84); ptr != 0 {
+		c.ForeignKeyClause = &ForeignKey{}
+		c.ForeignKeyClause.load(mod, ptr, sql)
+	}
+}
+
+type ForeignKey struct {
+	Table      string
+	Columns    []string
+	OnDelete   FKAction
+	OnUpdate   FKAction
+	Match      string
+	Deferrable FKDefType
+}
+
+func (f *ForeignKey) load(mod api.Module, ptr uint32, sql string) {
+	f.Table = loadString(mod, ptr+0, sql)
+
+	f.Columns = loadSlice(mod, ptr+8, func(ptr uint32, res *string) {
+		*res = loadString(mod, ptr, sql)
+	})
+
+	f.OnDelete = loadEnum[FKAction](mod, ptr+16)
+	f.OnUpdate = loadEnum[FKAction](mod, ptr+20)
+	f.Match = loadString(mod, ptr+24, sql)
+	f.Deferrable = loadEnum[FKDefType](mod, ptr+32)
+}
+
+func loadString(mod api.Module, ptr uint32, sql string) string {
+	off, _ := mod.Memory().ReadUint32Le(ptr + 0)
+	if off == 0 {
+		return ""
+	}
+	len, _ := mod.Memory().ReadUint32Le(ptr + 4)
+	return sql[off-sqlp : off+len-sqlp]
+}
+
+func loadSlice[T any](mod api.Module, ptr uint32, fn func(uint32, *T)) []T {
+	ref, _ := mod.Memory().ReadUint32Le(ptr + 4)
+	if ref == 0 {
+		return nil
+	}
+	len, _ := mod.Memory().ReadUint32Le(ptr + 0)
+	res := make([]T, len)
+	for i := range res {
+		fn(ref, &res[i])
+		ref += 4
+	}
+	return res
+}
+
+func loadEnum[T ~uint32](mod api.Module, ptr uint32) T {
+	val, _ := mod.Memory().ReadUint32Le(ptr)
+	return T(val)
+}
+
+func loadBool(mod api.Module, ptr uint32) bool {
+	val, _ := mod.Memory().ReadByte(ptr)
+	return val != 0
+}