| // Copyright 2015 The Vanadium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package store |
| |
| // TODO(sadovsky): Add retry loop. |
| func RunInTransaction(st Store, fn func(st StoreReadWriter) error) error { |
| tx := st.NewTransaction() |
| if err := fn(tx); err != nil { |
| tx.Abort() |
| return err |
| } |
| if err := tx.Commit(); err != nil { |
| // TODO(sadovsky): Commit() can fail for a number of reasons, e.g. RPC |
| // failure or ErrConcurrentTransaction. Depending on the cause of failure, |
| // it may be desirable to retry the Commit() and/or to call Abort(). For |
| // now, we always abort on a failed commit. |
| tx.Abort() |
| return err |
| } |
| return nil |
| } |
| |
| // CopyBytes copies elements from a source slice into a destination slice. |
| // The returned slice may be a sub-slice of dst if dst was large enough to hold |
| // src. Otherwise, a newly allocated slice will be returned. |
| func CopyBytes(dst, src []byte) []byte { |
| if cap(dst) < len(src) { |
| newlen := cap(dst)*2 + 2 |
| if newlen < len(src) { |
| newlen = len(src) |
| } |
| dst = make([]byte, newlen) |
| } |
| copy(dst, src) |
| return dst[:len(src)] |
| } |