sync/internal_api/public/read_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_INTERNAL_API_PUBLIC_READ_TRANSACTION_H_
   6 #define SYNC_INTERNAL_API_PUBLIC_READ_TRANSACTION_H_
   7
   8 #include "base/compiler_specific.h"
   9 #include "sync/base/sync_export.h"
  10 #include "sync/internal_api/public/base_transaction.h"
  11
  12 namespace tracked_objects {
  13 class Location;
  14 }  // namespace tracked_objects
  15
  16 namespace sync_pb {
  17 class DataTypeContext;
  18 }
  19
  20 namespace syncer {
  21
  22 struct UserShare;
  23
  24 // Sync API's ReadTransaction is a read-only BaseTransaction.  It wraps
  25 // a syncable::ReadTransaction.
  26 class SYNC_EXPORT ReadTransaction : public BaseTransaction {
  27  public:
  28   // Start a new read-only transaction on the specified repository.
  29   ReadTransaction(const tracked_objects::Location& from_here,
  30                   UserShare* share);
  31
  32   // Resume the middle of a transaction. Will not close transaction.
  33   ReadTransaction(UserShare* share, syncable::BaseTransaction* trans);
  34
  35   virtual ~ReadTransaction();
  36
  37   // BaseTransaction override.
  38   virtual syncable::BaseTransaction* GetWrappedTrans() const OVERRIDE;
  39
  40   // Return |transaction_version| of |type| stored in sync directory's
  41   // persisted info.
  42   int64 GetModelVersion(ModelType type) const;
  43
  44   // Fills |context| with the datatype context associated with |type|.
  45   void GetDataTypeContext(ModelType type,
  46                           sync_pb::DataTypeContext* context) const;
  47
  48  private:
  49   void* operator new(size_t size);  // Transaction is meant for stack use only.
  50
  51   // The underlying syncable object which this class wraps.
  52   syncable::BaseTransaction* transaction_;
  53   bool close_transaction_;
  54
  55   DISALLOW_COPY_AND_ASSIGN(ReadTransaction);
  56 };
  57
  58 }  // namespace syncer
  59
  60 #endif  // SYNC_INTERNAL_API_PUBLIC_READ_TRANSACTION_H_