sync/syncable/syncable_write_transaction.h

   1 // Copyright 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef SYNC_SYNCABLE_SYNCABLE_WRITE_TRANSACTION_H_
   6 #define SYNC_SYNCABLE_SYNCABLE_WRITE_TRANSACTION_H_
   7
   8 #include "sync/base/sync_export.h"
   9 #include "sync/syncable/entry_kernel.h"
  10 #include "sync/syncable/syncable_base_write_transaction.h"
  11
  12 namespace syncer {
  13 namespace syncable {
  14
  15 SYNC_EXPORT extern const int64 kInvalidTransactionVersion;
  16
  17 // Locks db in constructor, unlocks in destructor.
  18 class SYNC_EXPORT WriteTransaction : public BaseWriteTransaction {
  19  public:
  20   WriteTransaction(const tracked_objects::Location& from_here,
  21                    WriterTag writer, Directory* directory);
  22
  23   // Constructor used for getting back transaction version after making sync
  24   // API changes to one model. If model is changed by the transaction,
  25   // the new transaction version of the model and modified nodes will be saved
  26   // in |transaction_version| upon destruction of the transaction. If model is
  27   // not changed,  |transaction_version| will be kInvalidTransactionVersion.
  28   WriteTransaction(const tracked_objects::Location& from_here,
  29                    Directory* directory, int64* transaction_version);
  30
  31   virtual ~WriteTransaction();
  32
  33   virtual void TrackChangesTo(const EntryKernel* entry) OVERRIDE;
  34
  35  protected:
  36   // Overridden by tests.
  37   virtual void NotifyTransactionComplete(ModelTypeSet models_with_changes);
  38
  39  private:
  40   friend class MutableEntry;
  41
  42   // Clears |mutations_|.
  43   ImmutableEntryKernelMutationMap RecordMutations();
  44
  45   void UnlockAndNotify(const ImmutableEntryKernelMutationMap& mutations);
  46
  47   ModelTypeSet NotifyTransactionChangingAndEnding(
  48       const ImmutableEntryKernelMutationMap& mutations);
  49
  50   // Increment versions of the models whose entries are modified and set the
  51   // version on the changed entries.
  52   void UpdateTransactionVersion(const std::vector<int64>& entry_changed);
  53
  54   // Only the original fields are filled in until |RecordMutations()|.
  55   // We use a mutation map instead of a kernel set to avoid copying.
  56   EntryKernelMutationMap mutations_;
  57
  58   // Stores new transaction version of changed model and nodes if model is
  59   // indeed changed. kInvalidTransactionVersion otherwise. Not owned.
  60   int64* transaction_version_;
  61
  62   DISALLOW_COPY_AND_ASSIGN(WriteTransaction);
  63 };
  64
  65 }  // namespace syncable
  66 }  // namespace syncer
  67
  68 #endif //  SYNC_SYNCABLE_SYNCABLE_WRITE_TRANSACTION_H_