sync/engine/syncer_command.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_ENGINE_SYNCER_COMMAND_H_
   6 #define SYNC_ENGINE_SYNCER_COMMAND_H_
   7
   8 #include "base/basictypes.h"
   9
  10 #include "sync/base/sync_export.h"
  11 #include "sync/internal_api/public/util/syncer_error.h"
  12
  13 namespace syncer {
  14
  15 namespace sessions {
  16 class SyncSession;
  17 }
  18
  19 // Implementation of a simple command pattern intended to be driven by the
  20 // Syncer. SyncerCommand is abstract and all subclasses must implement
  21 // ExecuteImpl(). This is done so that chunks of syncer operation can be unit
  22 // tested.
  23 //
  24 // Example Usage:
  25 //
  26 //   SyncSession session = ...;
  27 //   SyncerCommand *cmd = SomeCommandFactory.createCommand(...);
  28 //   cmd->Execute(session);
  29 //   delete cmd;
  30
  31 class SYNC_EXPORT_PRIVATE SyncerCommand {
  32  public:
  33   SyncerCommand();
  34   virtual ~SyncerCommand();
  35
  36   // Execute dispatches to a derived class's ExecuteImpl.
  37   SyncerError Execute(sessions::SyncSession* session);
  38
  39   // ExecuteImpl is where derived classes actually do work.
  40   virtual SyncerError ExecuteImpl(sessions::SyncSession* session) = 0;
  41  private:
  42   DISALLOW_COPY_AND_ASSIGN(SyncerCommand);
  43 };
  44
  45 }  // namespace syncer
  46
  47 #endif  // SYNC_ENGINE_SYNCER_COMMAND_H_