Merge pull request #63 from Icinga/run-in-tx-method

Introduce `DB#ExecTx()` method

database/db.go

@@ -769,6 +769,31 @@ func (db *DB) Delete(
 	return db.DeleteStreamed(ctx, entityType, idsCh, onSuccess...)
 }
 
+// ExecTx executes the provided function within a database transaction.
+//
+// Starts a new transaction, executes the provided function, and commits the transaction
+// if the function succeeds. If the function returns an error, the transaction is rolled back.
+//
+// Returns an error if starting the transaction, executing the function, or committing the transaction fails.
+func (db *DB) ExecTx(ctx context.Context, fn func(context.Context, *sqlx.Tx) error) error {
+	tx, err := db.BeginTxx(ctx, nil)
+	if err != nil {
+		return errors.Wrap(err, "can't start transaction")
+	}
+	// We don't expect meaningful errors from rolling back the tx other than the sql.ErrTxDone, so just ignore it.
+	defer func() { _ = tx.Rollback() }()
+
+	if err := fn(ctx, tx); err != nil {
+		return errors.WithStack(err)
+	}
+
+	if err := tx.Commit(); err != nil {
+		return errors.Wrap(err, "can't commit transaction")
+	}
+
+	return nil
+}
+
 func (db *DB) GetSemaphoreForTable(table string) *semaphore.Weighted {
 	db.tableSemaphoresMu.Lock()
 	defer db.tableSemaphoresMu.Unlock()