| // Copyright (c) 2012 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 COMPONENTS_SYNC_ENGINE_IMPL_SYNCER_H_ |
| #define COMPONENTS_SYNC_ENGINE_IMPL_SYNCER_H_ |
| |
| #include <stdint.h> |
| |
| #include <vector> |
| |
| #include "base/gtest_prod_util.h" |
| #include "base/macros.h" |
| #include "components/sync/base/model_type.h" |
| #include "components/sync/base/syncer_error.h" |
| #include "components/sync/protocol/sync.pb.h" |
| |
| namespace syncer { |
| |
| class CancelationSignal; |
| class GetUpdatesDelegate; |
| class NudgeTracker; |
| class SyncCycle; |
| |
| // A Syncer provides a control interface for driving the sync cycle. These |
| // cycles consist of downloading updates, parsing the response (aka. process |
| // updates), applying updates while resolving conflicts, and committing local |
| // changes. Some of these steps may be skipped if they're deemed to be |
| // unnecessary. |
| // |
| // A Syncer instance expects to run on a dedicated thread. Calls to SyncShare() |
| // may take an unbounded amount of time because it may block on network I/O, on |
| // lock contention, or on tasks posted to other threads. |
| class Syncer { |
| public: |
| explicit Syncer(CancelationSignal* cancelation_signal); |
| virtual ~Syncer(); |
| |
| // Whether the syncer is in the middle of a sync cycle. |
| bool IsSyncing() const; |
| |
| // Fetches and applies updates, resolves conflicts and commits local changes |
| // for |request_types| as necessary until client and server states are in |
| // sync. The |nudge_tracker| contains state that describes why the client is |
| // out of sync and what must be done to bring it back into sync. |
| // Returns: false if an error occurred and retries should backoff, true |
| // otherwise. |
| virtual bool NormalSyncShare(ModelTypeSet request_types, |
| NudgeTracker* nudge_tracker, |
| SyncCycle* cycle); |
| |
| // Performs an initial download for the |request_types|. It is assumed that |
| // the specified types have no local state, and that their associated change |
| // processors are in "passive" mode, so none of the downloaded updates will be |
| // applied to the model. The |source| is sent up to the server for debug |
| // purposes. It describes the reson for performing this initial download. |
| // Returns: false if an error occurred and retries should backoff, true |
| // otherwise. |
| virtual bool ConfigureSyncShare(const ModelTypeSet& request_types, |
| sync_pb::SyncEnums::GetUpdatesOrigin origin, |
| SyncCycle* cycle); |
| |
| // Requests to download updates for the |request_types|. For a well-behaved |
| // client with a working connection to the invalidations server, this should |
| // be unnecessary. It may be invoked periodically to try to keep the client |
| // in sync despite bugs or transient failures. |
| // Returns: false if an error occurred and retries should backoff, true |
| // otherwise. |
| virtual bool PollSyncShare(ModelTypeSet request_types, SyncCycle* cycle); |
| |
| private: |
| bool DownloadAndApplyUpdates(ModelTypeSet* request_types, |
| SyncCycle* cycle, |
| const GetUpdatesDelegate& delegate); |
| |
| // This function will commit batches of unsynced items to the server until the |
| // number of unsynced and ready to commit items reaches zero or an error is |
| // encountered. A request to exit early will be treated as an error and will |
| // abort any blocking operations. |
| SyncerError BuildAndPostCommits(const ModelTypeSet& request_types, |
| NudgeTracker* nudge_tracker, |
| SyncCycle* cycle); |
| |
| // Whether an early exist was requested due to a cancelation signal. |
| bool ExitRequested(); |
| |
| bool HandleCycleEnd(SyncCycle* cycle, |
| sync_pb::SyncEnums::GetUpdatesOrigin origin); |
| |
| CancelationSignal* const cancelation_signal_; |
| |
| // Whether the syncer is in the middle of a sync attempt. |
| bool is_syncing_; |
| |
| DISALLOW_COPY_AND_ASSIGN(Syncer); |
| }; |
| |
| } // namespace syncer |
| |
| #endif // COMPONENTS_SYNC_ENGINE_IMPL_SYNCER_H_ |