| // 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 |
| |
| import ( |
| "v.io/v23/verror" |
| ) |
| |
| func RunInTransaction(st Store, fn func(st StoreReadWriter) error) error { |
| // TODO(rogulenko): We should eventually give up with |
| // ErrConcurrentTransaction. |
| // TODO(rogulenko): Fail on RPC errors. |
| for { |
| tx := st.NewTransaction() |
| if err := fn(tx); err != nil { |
| tx.Abort() |
| return err |
| } |
| err := tx.Commit() |
| if err == nil { |
| return nil |
| } |
| if verror.ErrorID(err) == ErrConcurrentTransaction.ID { |
| continue |
| } |
| return err |
| } |
| } |
| |
| // 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. |
| // TODO(rogulenko): add some tests. |
| 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) |
| } |
| dst = dst[:len(src)] |
| copy(dst, src) |
| return dst |
| } |
| |
| ////////////////////////////////////////////////////////////// |
| // Read and Write types used for storing transcation reads |
| // and uncommitted writes. |
| |
| type ScanRange struct { |
| Start, Limit []byte |
| } |
| |
| type ReadSet struct { |
| Keys [][]byte |
| Ranges []ScanRange |
| } |
| |
| type WriteType int |
| |
| const ( |
| PutOp WriteType = iota |
| DeleteOp |
| ) |
| |
| type WriteOp struct { |
| T WriteType |
| Key []byte |
| Value []byte |
| } |
| |
| type WriteOpArray []WriteOp |
| |
| func (a WriteOpArray) Len() int { |
| return len(a) |
| } |
| |
| func (a WriteOpArray) Less(i, j int) bool { |
| return string(a[i].Key) < string(a[j].Key) |
| } |
| |
| func (a WriteOpArray) Swap(i, j int) { |
| a[i], a[j] = a[j], a[i] |
| } |