| // Copyright 2014 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef SYNC_ENGINE_MODEL_TYPE_SYNC_WORKER_IMPL_H_ |
| #define SYNC_ENGINE_MODEL_TYPE_SYNC_WORKER_IMPL_H_ |
| |
| #include "base/memory/weak_ptr.h" |
| #include "base/stl_util.h" |
| #include "base/threading/non_thread_safe.h" |
| #include "sync/base/sync_export.h" |
| #include "sync/engine/commit_contributor.h" |
| #include "sync/engine/model_type_sync_worker.h" |
| #include "sync/engine/non_blocking_sync_common.h" |
| #include "sync/engine/nudge_handler.h" |
| #include "sync/engine/update_handler.h" |
| #include "sync/internal_api/public/base/model_type.h" |
| #include "sync/protocol/sync.pb.h" |
| |
| namespace base { |
| class SingleThreadTaskRunner; |
| } |
| |
| namespace syncer { |
| |
| class ModelTypeSyncProxy; |
| class EntityTracker; |
| |
| // A smart cache for sync types that use message passing (rather than |
| // transactions and the syncable::Directory) to communicate with the sync |
| // thread. |
| // |
| // When the non-blocking sync type wants to talk with the sync server, it will |
| // send a message from its thread to this object on the sync thread. This |
| // object ensures the appropriate sync server communication gets scheduled and |
| // executed. The response, if any, will be returned to the non-blocking sync |
| // type's thread eventually. |
| // |
| // This object also has a role to play in communications in the opposite |
| // direction. Sometimes the sync thread will receive changes from the sync |
| // server and deliver them here. This object will post this information back to |
| // the appropriate component on the model type's thread. |
| // |
| // This object does more than just pass along messages. It understands the sync |
| // protocol, and it can make decisions when it sees conflicting messages. For |
| // example, if the sync server sends down an update for a sync entity that is |
| // currently pending for commit, this object will detect this condition and |
| // cancel the pending commit. |
| class SYNC_EXPORT ModelTypeSyncWorkerImpl : public UpdateHandler, |
| public CommitContributor, |
| public ModelTypeSyncWorker, |
| public base::NonThreadSafe { |
| public: |
| ModelTypeSyncWorkerImpl(ModelType type, |
| const DataTypeState& initial_state, |
| NudgeHandler* nudge_handler, |
| scoped_ptr<ModelTypeSyncProxy> type_sync_proxy); |
| virtual ~ModelTypeSyncWorkerImpl(); |
| |
| ModelType GetModelType() const; |
| |
| // UpdateHandler implementation. |
| virtual void GetDownloadProgress( |
| sync_pb::DataTypeProgressMarker* progress_marker) const OVERRIDE; |
| virtual void GetDataTypeContext( |
| sync_pb::DataTypeContext* context) const OVERRIDE; |
| virtual SyncerError ProcessGetUpdatesResponse( |
| const sync_pb::DataTypeProgressMarker& progress_marker, |
| const sync_pb::DataTypeContext& mutated_context, |
| const SyncEntityList& applicable_updates, |
| sessions::StatusController* status) OVERRIDE; |
| virtual void ApplyUpdates(sessions::StatusController* status) OVERRIDE; |
| virtual void PassiveApplyUpdates(sessions::StatusController* status) OVERRIDE; |
| |
| // ModelTypeSyncWorker implementation. |
| virtual void EnqueueForCommit( |
| const CommitRequestDataList& request_list) OVERRIDE; |
| |
| // CommitContributor implementation. |
| virtual scoped_ptr<CommitContribution> GetContribution( |
| size_t max_entries) OVERRIDE; |
| |
| // Callback for when our contribution gets a response. |
| void OnCommitResponse(const CommitResponseDataList& response_list); |
| |
| base::WeakPtr<ModelTypeSyncWorkerImpl> AsWeakPtr(); |
| |
| private: |
| typedef std::map<std::string, EntityTracker*> EntityMap; |
| |
| // Stores a single commit request in this object's internal state. |
| void StorePendingCommit(const CommitRequestData& request); |
| |
| // Returns true if all data type state required for commits is available. In |
| // practice, this means that it returns true from the time this object first |
| // receives notice of a successful update fetch from the server. |
| bool CanCommitItems() const; |
| |
| // Initializes the parts of a commit entity that are the responsibility of |
| // this class, and not the EntityTracker. Some fields, like the |
| // client-assigned ID, can only be set by an entity with knowledge of the |
| // entire data type's state. |
| void HelpInitializeCommitEntity(sync_pb::SyncEntity* commit_entity); |
| |
| ModelType type_; |
| |
| // State that applies to the entire model type. |
| DataTypeState data_type_state_; |
| |
| // Pointer to the ModelTypeSyncProxy associated with this worker. |
| // This is NULL when no proxy is connected.. |
| scoped_ptr<ModelTypeSyncProxy> type_sync_proxy_; |
| |
| // Interface used to access and send nudges to the sync scheduler. Not owned. |
| NudgeHandler* nudge_handler_; |
| |
| // A map of per-entity information known to this object. |
| // |
| // When commits are pending, their information is stored here. This |
| // information is dropped from memory when the commit succeeds or gets |
| // cancelled. |
| // |
| // This also stores some information related to received server state in |
| // order to implement reflection blocking and conflict detection. This |
| // information is kept in memory indefinitely. With a bit more coordination |
| // with the model thread, we could optimize this to reduce memory usage in |
| // the steady state. |
| EntityMap entities_; |
| STLValueDeleter<EntityMap> entities_deleter_; |
| |
| base::WeakPtrFactory<ModelTypeSyncWorkerImpl> weak_ptr_factory_; |
| }; |
| |
| } // namespace syncer |
| |
| #endif // SYNC_ENGINE_MODEL_TYPE_SYNC_WORKER_IMPL_H_ |