diff options
Diffstat (limited to 'vendor/google.golang.org/appengine/datastore/transaction.go')
| -rw-r--r-- | vendor/google.golang.org/appengine/datastore/transaction.go | 87 |
1 files changed, 0 insertions, 87 deletions
diff --git a/vendor/google.golang.org/appengine/datastore/transaction.go b/vendor/google.golang.org/appengine/datastore/transaction.go deleted file mode 100644 index a7f3f2b28..000000000 --- a/vendor/google.golang.org/appengine/datastore/transaction.go +++ /dev/null @@ -1,87 +0,0 @@ -// Copyright 2011 Google Inc. All rights reserved. -// Use of this source code is governed by the Apache 2.0 -// license that can be found in the LICENSE file. - -package datastore - -import ( - "errors" - - "golang.org/x/net/context" - - "google.golang.org/appengine/internal" - pb "google.golang.org/appengine/internal/datastore" -) - -func init() { - internal.RegisterTransactionSetter(func(x *pb.Query, t *pb.Transaction) { - x.Transaction = t - }) - internal.RegisterTransactionSetter(func(x *pb.GetRequest, t *pb.Transaction) { - x.Transaction = t - }) - internal.RegisterTransactionSetter(func(x *pb.PutRequest, t *pb.Transaction) { - x.Transaction = t - }) - internal.RegisterTransactionSetter(func(x *pb.DeleteRequest, t *pb.Transaction) { - x.Transaction = t - }) -} - -// ErrConcurrentTransaction is returned when a transaction is rolled back due -// to a conflict with a concurrent transaction. -var ErrConcurrentTransaction = errors.New("datastore: concurrent transaction") - -// RunInTransaction runs f in a transaction. It calls f with a transaction -// context tc that f should use for all App Engine operations. -// -// If f returns nil, RunInTransaction attempts to commit the transaction, -// returning nil if it succeeds. If the commit fails due to a conflicting -// transaction, RunInTransaction retries f, each time with a new transaction -// context. It gives up and returns ErrConcurrentTransaction after three -// failed attempts. The number of attempts can be configured by specifying -// TransactionOptions.Attempts. -// -// If f returns non-nil, then any datastore changes will not be applied and -// RunInTransaction returns that same error. The function f is not retried. -// -// Note that when f returns, the transaction is not yet committed. Calling code -// must be careful not to assume that any of f's changes have been committed -// until RunInTransaction returns nil. -// -// Since f may be called multiple times, f should usually be idempotent. -// datastore.Get is not idempotent when unmarshaling slice fields. -// -// Nested transactions are not supported; c may not be a transaction context. -func RunInTransaction(c context.Context, f func(tc context.Context) error, opts *TransactionOptions) error { - xg := false - if opts != nil { - xg = opts.XG - } - attempts := 3 - if opts != nil && opts.Attempts > 0 { - attempts = opts.Attempts - } - for i := 0; i < attempts; i++ { - if err := internal.RunTransactionOnce(c, f, xg); err != internal.ErrConcurrentTransaction { - return err - } - } - return ErrConcurrentTransaction -} - -// TransactionOptions are the options for running a transaction. -type TransactionOptions struct { - // XG is whether the transaction can cross multiple entity groups. In - // comparison, a single group transaction is one where all datastore keys - // used have the same root key. Note that cross group transactions do not - // have the same behavior as single group transactions. In particular, it - // is much more likely to see partially applied transactions in different - // entity groups, in global queries. - // It is valid to set XG to true even if the transaction is within a - // single entity group. - XG bool - // Attempts controls the number of retries to perform when commits fail - // due to a conflicting transaction. If omitted, it defaults to 3. - Attempts int -} |