Driver savepoints.

driver/driver.go

@@ -269,6 +269,12 @@ func (c *conn) ExecContext(ctx context.Context, query string, args []driver.Name
 		return nil, driver.ErrSkip
 	}
 
+	if savept, ok := ctx.(*saveptCtx); ok {
+		// Called from driver.Savepoint.
+		savept.Savepoint = c.Savepoint()
+		return resultRowsAffected(-1), nil
+	}
+
 	old := c.Conn.SetInterrupt(ctx)
 	defer c.Conn.SetInterrupt(old)
 

driver/savepoint.go

@@ -0,0 +1,27 @@
+package driver
+
+import (
+	"database/sql"
+	"time"
+
+	"github.com/ncruces/go-sqlite3"
+)
+
+// Savepoint establishes a new transaction savepoint.
+//
+// https://www.sqlite.org/lang_savepoint.html
+func Savepoint(tx *sql.Tx) sqlite3.Savepoint {
+	var ctx saveptCtx
+	tx.ExecContext(&ctx, "")
+	return ctx.Savepoint
+}
+
+type saveptCtx struct{ sqlite3.Savepoint }
+
+func (*saveptCtx) Deadline() (deadline time.Time, ok bool) { return }
+
+func (*saveptCtx) Done() <-chan struct{} { return nil }
+
+func (*saveptCtx) Err() error { return nil }
+
+func (*saveptCtx) Value(key any) any { return nil }

ext/blob/blob_test.go

@@ -21,7 +21,6 @@ func Example() {
 	if err != nil {
 		log.Fatal(err)
 	}
-	defer os.Remove("demo.db")
 	defer db.Close()
 
 	_, err = db.Exec(`CREATE TABLE IF NOT EXISTS test (col)`)

tx.go

@@ -7,6 +7,7 @@ import (
 	"math/rand"
 	"runtime"
 	"strconv"
+	"strings"
 )
 
 // Tx is an in-progress database transaction.
@@ -119,17 +120,8 @@ type Savepoint struct {
 //
 // https://www.sqlite.org/lang_savepoint.html
 func (c *Conn) Savepoint() Savepoint {
-	name := "sqlite3.Savepoint"
-	var pc [1]uintptr
-	if n := runtime.Callers(2, pc[:]); n > 0 {
-		frames := runtime.CallersFrames(pc[:n])
-		frame, _ := frames.Next()
-		if frame.Function != "" {
-			name = frame.Function
-		}
-	}
 	// Names can be reused; this makes catching bugs more likely.
-	name += "#" + strconv.Itoa(int(rand.Int31()))
+	name := saveptName() + "_" + strconv.Itoa(int(rand.Int31()))
 
 	err := c.txExecInterrupted(fmt.Sprintf("SAVEPOINT %q;", name))
 	if err != nil {
@@ -138,6 +130,27 @@ func (c *Conn) Savepoint() Savepoint {
 	return Savepoint{c: c, name: name}
 }
 
+func saveptName() (name string) {
+	defer func() {
+		if name == "" {
+			name = "sqlite3.Savepoint"
+		}
+	}()
+
+	var pc [8]uintptr
+	n := runtime.Callers(3, pc[:])
+	if n <= 0 {
+		return ""
+	}
+	frames := runtime.CallersFrames(pc[:n])
+	frame, more := frames.Next()
+	for more && (strings.HasPrefix(frame.Function, "database/sql.") ||
+		strings.HasPrefix(frame.Function, "github.com/ncruces/go-sqlite3/driver.")) {
+		frame, more = frames.Next()
+	}
+	return frame.Function
+}
+
 // Release releases the savepoint rolling back any changes
 // if *error points to a non-nil error.
 //