[Sync] Move //sync to //components/sync.

sync/engine/syncer.h

-// 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 SYNC_ENGINE_SYNCER_H_
-#define SYNC_ENGINE_SYNCER_H_
-
-#include <stdint.h>
-
-#include <utility>
-#include <vector>
-
-#include "base/callback.h"
-#include "base/gtest_prod_util.h"
-#include "base/macros.h"
-#include "base/synchronization/lock.h"
-#include "sync/base/sync_export.h"
-#include "sync/engine/conflict_resolver.h"
-#include "sync/engine/syncer_types.h"
-#include "sync/internal_api/public/base/model_type.h"
-#include "sync/sessions/sync_session.h"
-#include "sync/util/extensions_activity.h"
-
-namespace syncer {
-
-class CancelationSignal;
-class CommitProcessor;
-class GetUpdatesProcessor;
-
-// 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 SYNC_EXPORT Syncer {
- public:
-  typedef std::vector<int64_t> UnsyncedMetaHandles;
-
-  explicit Syncer(CancelationSignal* cancelation_signal);
-  virtual ~Syncer();
-
-  // Whether an early exist was requested due to a cancelation signal.
-  bool ExitRequested();
-
-  // 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,
-                               sessions::NudgeTracker* nudge_tracker,
-                               sessions::SyncSession* session);
-
-  // 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(
-      ModelTypeSet request_types,
-      sync_pb::GetUpdatesCallerInfo::GetUpdatesSource source,
-      sessions::SyncSession* session);
-
-  // 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,
-                             sessions::SyncSession* session);
-
-  // Posts a ClearServerData command.
-  // Returns: false if an error occurred and retries should backoff, true
-  // otherwise.
-  virtual bool PostClearServerData(sessions::SyncSession* session);
-
- private:
-  friend class SyncerTest;
-  FRIEND_TEST_ALL_PREFIXES(SyncerTest, NameClashWithResolver);
-  FRIEND_TEST_ALL_PREFIXES(SyncerTest, IllegalAndLegalUpdates);
-  FRIEND_TEST_ALL_PREFIXES(SyncerTest, TestCommitListOrderingAndNewParent);
-  FRIEND_TEST_ALL_PREFIXES(SyncerTest,
-                           TestCommitListOrderingAndNewParentAndChild);
-  FRIEND_TEST_ALL_PREFIXES(SyncerTest, TestCommitListOrderingCounterexample);
-  FRIEND_TEST_ALL_PREFIXES(SyncerTest, TestCommitListOrderingWithNesting);
-  FRIEND_TEST_ALL_PREFIXES(SyncerTest, TestCommitListOrderingWithNewItems);
-  FRIEND_TEST_ALL_PREFIXES(SyncerTest, TestGetUnsyncedAndSimpleCommit);
-  FRIEND_TEST_ALL_PREFIXES(SyncerTest, TestPurgeWhileUnsynced);
-  FRIEND_TEST_ALL_PREFIXES(SyncerTest, TestPurgeWhileUnapplied);
-  FRIEND_TEST_ALL_PREFIXES(SyncerTest, UnappliedUpdateDuringCommit);
-  FRIEND_TEST_ALL_PREFIXES(SyncerTest, DeletingEntryInFolder);
-  FRIEND_TEST_ALL_PREFIXES(SyncerTest,
-                           LongChangelistCreatesFakeOrphanedEntries);
-  FRIEND_TEST_ALL_PREFIXES(SyncerTest, QuicklyMergeDualCreatedHierarchy);
-  FRIEND_TEST_ALL_PREFIXES(SyncerTest, LongChangelistWithApplicationConflict);
-  FRIEND_TEST_ALL_PREFIXES(SyncerTest, DeletingEntryWithLocalEdits);
-  FRIEND_TEST_ALL_PREFIXES(EntryCreatedInNewFolderTest,
-                           EntryCreatedInNewFolderMidSync);
-
-  bool DownloadAndApplyUpdates(
-      ModelTypeSet* request_types,
-      sessions::SyncSession* session,
-      GetUpdatesProcessor* get_updates_processor,
-      bool create_mobile_bookmarks_folder);
-
-  // 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(ModelTypeSet request_types,
-                                  sessions::NudgeTracker* nudge_tracker,
-                                  sessions::SyncSession* session,
-                                  CommitProcessor* commit_processor);
-
-  void HandleCycleBegin(sessions::SyncSession* session);
-  bool HandleCycleEnd(
-      sessions::SyncSession* session,
-      sync_pb::GetUpdatesCallerInfo::GetUpdatesSource source);
-
-  syncer::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  // SYNC_ENGINE_SYNCER_H_