sync/internal_api/sync_core_proxy_impl.h

   1 // Copyright 2014 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_SYNC_CORE_PROXY_IMPL_H_
   6 #define SYNC_INTERNAL_API_SYNC_CORE_PROXY_IMPL_H_
   7
   8 #include "base/memory/scoped_ptr.h"
   9 #include "base/memory/weak_ptr.h"
  10 #include "base/sequenced_task_runner.h"
  11 #include "sync/base/sync_export.h"
  12 #include "sync/internal_api/public/base/model_type.h"
  13 #include "sync/internal_api/public/sync_core_proxy.h"
  14
  15 namespace syncer {
  16
  17 class SyncCore;
  18 class NonBlockingTypeProcessor;
  19
  20 // Encapsulates a reference to the sync core and the thread it's running on.
  21 // Used by sync's data types to connect with the sync core.
  22 //
  23 // It is epxected that this object will be copied to and used on many different
  24 // threads.  It is small and safe to pass by value.
  25 class SYNC_EXPORT_PRIVATE SyncCoreProxyImpl : public SyncCoreProxy {
  26  public:
  27   SyncCoreProxyImpl(
  28       scoped_refptr<base::SequencedTaskRunner> sync_task_runner,
  29       base::WeakPtr<SyncCore> sync_core);
  30   virtual ~SyncCoreProxyImpl();
  31
  32   // Attempts to connect a non-blocking type to the sync core.
  33   //
  34   // This may fail under some unusual circumstances, like shutdown.  Due to the
  35   // nature of WeakPtrs and cross-thread communication, the caller will be
  36   // unable to distinguish a slow success from failure.
  37   //
  38   // Must be called from the thread where the data type lives.
  39   virtual void ConnectTypeToCore(
  40       syncer::ModelType type,
  41       base::WeakPtr<NonBlockingTypeProcessor> type_processor) OVERRIDE;
  42
  43   virtual scoped_ptr<SyncCoreProxy> Clone() const OVERRIDE;
  44
  45  private:
  46   // A SequencedTaskRunner representing the thread where the SyncCore lives.
  47   scoped_refptr<base::SequencedTaskRunner> sync_task_runner_;
  48
  49   // The SyncCore this object is wrapping.
  50   base::WeakPtr<SyncCore> sync_core_;
  51 };
  52
  53 }  // namespace syncer
  54
  55 #endif  // SYNC_INTERNAL_API_SYNC_CORE_PROXY_IMPL_H_