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

sync/syncable/syncable_delete_journal.h

-// Copyright 2013 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_SYNCABLE_SYNCABLE_DELETE_JOURNAL_H_
-#define SYNC_SYNCABLE_SYNCABLE_DELETE_JOURNAL_H_
-
-#include <stddef.h>
-
-#include <set>
-
-#include "base/gtest_prod_util.h"
-#include "base/macros.h"
-#include "base/synchronization/lock.h"
-#include "sync/base/sync_export.h"
-#include "sync/syncable/metahandle_set.h"
-#include "sync/syncable/syncable-inl.h"
-
-namespace syncer {
-namespace syncable {
-
-class BaseTransaction;
-struct EntryKernel;
-
-typedef std::set<const EntryKernel*, LessField<IdField, ID> > JournalIndex;
-
-// DeleteJournal manages deleted entries that are not in sync directory until
-// it's safe to drop them after the deletion is confirmed with native models.
-// DeleteJournal is thread-safe and can be accessed on any thread. Has to hold
-// a valid transaction object when calling methods of DeleteJournal, thus each
-// method requires a non-null |trans| parameter.
-class SYNC_EXPORT DeleteJournal {
- public:
-  // Initialize |delete_journals_| using |intitial_journal|, whose content is
-  // destroyed during initialization.
-  explicit DeleteJournal(JournalIndex* initial_journal);
-  ~DeleteJournal();
-
-  // For testing only.
-  size_t GetDeleteJournalSize(BaseTransaction* trans) const;
-
-  // Add/remove |entry| to/from |delete_journals_| according to its
-  // SERVER_IS_DEL field and |was_deleted|. Called on sync thread.
-  void UpdateDeleteJournalForServerDelete(BaseTransaction* trans,
-                                          bool was_deleted,
-                                          const EntryKernel& entry);
-
-  // Return entries of specified type in |delete_journals_|. This should be
-  // called ONCE in model association. |deleted_entries| can be used to
-  // detect deleted sync data that's not persisted in native model to
-  // prevent back-from-dead problem. |deleted_entries| are only valid during
-  // lifetime of |trans|. |type| is added to |passive_delete_journal_types_| to
-  // enable periodically saving/clearing of delete journals of |type| because
-  // new journals added later are not needed until next model association.
-  // Can be called on any thread.
-  void GetDeleteJournals(BaseTransaction* trans, ModelType type,
-                         EntryKernelSet* deleted_entries);
-
-  // Purge entries of specified type in |delete_journals_| if their handles are
-  // in |to_purge|. This should be called after model association and
-  // |to_purge| should contain handles of the entries whose deletions are
-  // confirmed in native model. Can be called on any thread.
-  void PurgeDeleteJournals(BaseTransaction* trans,
-                           const MetahandleSet& to_purge);
-
-  // Move entries in |delete_journals_| whose types are in
-  // |passive_delete_journal_types_| to |journal_entries|. Move handles in
-  // |delete_journals_to_purge_| to |journals_to_purge|. Called on sync thread.
-  void TakeSnapshotAndClear(BaseTransaction* trans,
-                            EntryKernelSet* journal_entries,
-                            MetahandleSet* journals_to_purge);
-
-  // Add |entries| to |delete_journals_| regardless of their SERVER_IS_DEL
-  // value. This is used to:
-  // * restore delete journals from snapshot if snapshot failed to save.
-  // * batch add entries of a data type with unrecoverable error to delete
-  //   journal before purging them.
-  // Called on sync thread.
-  void AddJournalBatch(BaseTransaction* trans, const EntryKernelSet& entries);
-
-  // Return true if delete journals of |type| are maintained.
-  static bool IsDeleteJournalEnabled(ModelType type);
-
- private:
-  FRIEND_TEST_ALL_PREFIXES(SyncableDirectoryTest, ManageDeleteJournals);
-
-  // Contains deleted entries that may not be persisted in native models. And
-  // in case of unrecoverable error, all purged entries are moved here for
-  // bookkeeping to prevent back-from-dead entries that are deleted elsewhere
-  // when sync's down.
-  JournalIndex delete_journals_;
-
-  // Contains meta handles of deleted entries that have been persisted or
-  // undeleted, thus can be removed from database.
-  MetahandleSet delete_journals_to_purge_;
-
-  // Delete journals of these types can be cleared from memory after being
-  // saved to database.
-  ModelTypeSet passive_delete_journal_types_;
-
-  DISALLOW_COPY_AND_ASSIGN(DeleteJournal);
-};
-
-}  // namespace syncable
-}  // namespace syncer
-
-#endif  // SYNC_SYNCABLE_SYNCABLE_DELETE_JOURNAL_H_