Towards bulk.

bulk.go

@@ -0,0 +1,88 @@
+package sqlite3
+
+import "github.com/ncruces/go-sqlite3/internal/util"
+
+type Bulk struct {
+	c      *Conn
+	prefix string
+	suffix string
+	buffer []byte
+	bufptr uint32
+}
+
+const _BULK_SIZE = 1024 * 1024
+
+func (c *Conn) CreateBulk(prefix, suffix string) (*Bulk, error) {
+	if len(prefix)+len(suffix) > _BULK_SIZE/2 {
+		return nil, TOOBIG
+	}
+	ptr := c.new(_BULK_SIZE)
+	buf := util.View(c.mod, ptr, _BULK_SIZE)
+	copy(buf, prefix)
+	buf = buf[len(prefix):len(prefix)]
+	return &Bulk{
+		c:      c,
+		prefix: prefix,
+		suffix: suffix,
+		buffer: buf,
+		bufptr: ptr,
+	}, nil
+}
+
+func (b *Bulk) Close() error {
+	if b == nil || b.c == nil {
+		return nil
+	}
+
+	err := b.Flush()
+	b.c.free(b.bufptr)
+	b.c = nil
+	return err
+}
+
+func (b *Bulk) Flush() error {
+	if len(b.buffer) == 0 {
+		return nil
+	}
+	if cap(b.buffer)-len(b.buffer) <= len(b.suffix) {
+		return TOOBIG
+	}
+	b.c.checkInterrupt(b.c.handle)
+	b.buffer = append(b.buffer, b.suffix...)
+	b.buffer = append(b.buffer, 0)
+	b.buffer = b.buffer[:0]
+	r := b.c.call("sqlite3_exec", uint64(b.c.handle), uint64(b.bufptr), 0, 0, 0)
+	return b.c.error(r)
+}
+
+func (b *Bulk) AppendRow(args ...any) error {
+	buf := b.buffer
+
+	if off := len(buf); off != 0 {
+		buf = append(buf[off:], ',')
+	}
+
+	buf = append(buf, '(')
+	for i, arg := range args {
+		if i != 0 {
+			buf = append(buf, ',')
+		}
+		buf = append(buf, Quote(arg)...)
+	}
+	buf = append(buf, ')')
+
+	if len(buf)+len(b.suffix) >= cap(b.buffer)-len(b.buffer) {
+		if err := b.Flush(); err != nil {
+			return err
+		}
+		if buf[0] == ',' {
+			buf = buf[1:]
+		}
+	}
+	if len(buf)+len(b.suffix) >= cap(b.buffer)-len(b.buffer) {
+		return TOOBIG
+	}
+
+	b.buffer = append(b.buffer, buf...)
+	return nil
+}

bulk_test.go

@@ -0,0 +1,60 @@
+package sqlite3_test
+
+import (
+	"fmt"
+	"log"
+
+	"github.com/ncruces/go-sqlite3"
+)
+
+func ExampleConn_CreateBulk() {
+	db, err := sqlite3.Open(":memory:")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer db.Close()
+
+	err = db.Exec(`CREATE TABLE users (id INT, name VARCHAR(10))`)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	bulk, err := db.CreateBulk(`INSERT INTO users (id, name) VALUES`, ``)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer bulk.Close()
+
+	for _, row := range [][]any{
+		{0, "go"},
+		{1, "zig"},
+		{2, "whatever"},
+	} {
+		err = bulk.AppendRow(row...)
+		if err != nil {
+			log.Fatal(err)
+		}
+	}
+
+	err = bulk.Flush()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	stmt, _, err := db.Prepare(`SELECT id, name FROM users`)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer stmt.Close()
+
+	for stmt.Step() {
+		fmt.Println(stmt.ColumnInt(0), stmt.ColumnText(1))
+	}
+	if err := stmt.Err(); err != nil {
+		log.Fatal(err)
+	}
+	// Output:
+	// 0 go
+	// 1 zig
+	// 2 whatever
+}

driver/driver.go

@@ -665,7 +665,7 @@ func (r *rows) Next(dest []driver.Value) error {
 	}
 
 	data := unsafe.Slice((*any)(unsafe.SliceData(dest)), len(dest))
-	err := r.Stmt.Columns(data)
+	err := r.Stmt.Columns(data...)
 	for i := range dest {
 		if t, ok := r.decodeTime(i, dest[i]); ok {
 			dest[i] = t

stmt.go

@@ -637,7 +637,7 @@ func (s *Stmt) ColumnValue(col int) Value {
 // [TEXT] as string, and [BLOB] as []byte.
 // Any []byte are owned by SQLite and may be invalidated by
 // subsequent calls to [Stmt] methods.
-func (s *Stmt) Columns(dest []any) error {
+func (s *Stmt) Columns(dest ...any) error {
 	defer s.c.arena.mark()()
 	count := uint64(len(dest))
 	typePtr := s.c.arena.new(count)