[Sync] Move 'sync' target to sync/

chrome/browser/sync/syncable/directory_backing_store.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 CHROME_BROWSER_SYNC_SYNCABLE_DIRECTORY_BACKING_STORE_H_
-#define CHROME_BROWSER_SYNC_SYNCABLE_DIRECTORY_BACKING_STORE_H_
-#pragma once
-
-#include <string>
-
-#include "base/memory/scoped_ptr.h"
-#include "base/threading/non_thread_safe.h"
-#include "chrome/browser/sync/syncable/dir_open_result.h"
-#include "chrome/browser/sync/syncable/model_type.h"
-#include "chrome/browser/sync/syncable/syncable.h"
-#include "sql/connection.h"
-#include "sql/statement.h"
-
-namespace sync_pb {
-class EntitySpecifics;
-}
-
-namespace syncable {
-
-struct ColumnSpec;
-typedef Directory::MetahandlesIndex MetahandlesIndex;
-
-// Interface that provides persistence for a syncable::Directory object. You can
-// load all the persisted data to prime a syncable::Directory on startup by
-// invoking Load.  The only other thing you (or more correctly, a Directory) can
-// do here is save any changes that have occurred since calling Load, which can
-// be done periodically as often as desired.
-//
-// The DirectoryBackingStore will own an sqlite lock on its database for most of
-// its lifetime.  You must not have two DirectoryBackingStore objects accessing
-// the database simultaneously.  Because the lock exists at the database level,
-// not even two separate browser instances would be able to acquire it
-// simultaneously.
-//
-// This class is abstract so that we can extend it in interesting ways for use
-// in tests.  The concrete class used in non-test scenarios is
-// OnDiskDirectoryBackingStore.
-class DirectoryBackingStore : public base::NonThreadSafe {
- public:
-  explicit DirectoryBackingStore(const std::string& dir_name);
-  virtual ~DirectoryBackingStore();
-
-  // Loads and drops all currently persisted meta entries into |entry_bucket|
-  // and loads appropriate persisted kernel info into |info_bucket|.
-  //
-  // This function can perform some cleanup tasks behind the scenes.  It will
-  // clean up unused entries from the database and migrate to the latest
-  // database version.  The caller can safely ignore these details.
-  //
-  // NOTE: On success (return value of OPENED), the buckets are populated with
-  // newly allocated items, meaning ownership is bestowed upon the caller.
-  virtual DirOpenResult Load(MetahandlesIndex* entry_bucket,
-                             Directory::KernelLoadInfo* kernel_load_info) = 0;
-
-  // Updates the on-disk store with the input |snapshot| as a database
-  // transaction.  Does NOT open any syncable transactions as this would cause
-  // opening transactions elsewhere to block on synchronous I/O.
-  // DO NOT CALL THIS FROM MORE THAN ONE THREAD EVER.  Also, whichever thread
-  // calls SaveChanges *must* be the thread that owns/destroys |this|.
-  virtual bool SaveChanges(const Directory::SaveChangesSnapshot& snapshot);
-
- protected:
-  // For test classes.
-  DirectoryBackingStore(const std::string& dir_name,
-                        sql::Connection* connection);
-
-  // General Directory initialization and load helpers.
-  bool InitializeTables();
-  bool CreateTables();
-
-  // Create 'share_info' or 'temp_share_info' depending on value of
-  // is_temporary. Returns an sqlite
-  bool CreateShareInfoTable(bool is_temporary);
-
-  bool CreateShareInfoTableVersion71(bool is_temporary);
-  // Create 'metas' or 'temp_metas' depending on value of is_temporary.
-  bool CreateMetasTable(bool is_temporary);
-  bool CreateModelsTable();
-  bool CreateV71ModelsTable();
-
-  // We don't need to load any synced and applied deleted entries, we can
-  // in fact just purge them forever on startup.
-  bool DropDeletedEntries();
-  // Drops a table if it exists, harmless if the table did not already exist.
-  bool SafeDropTable(const char* table_name);
-
-  // Load helpers for entries and attributes.
-  bool LoadEntries(MetahandlesIndex* entry_bucket);
-  bool LoadInfo(Directory::KernelLoadInfo* info);
-
-  // Save/update helpers for entries.  Return false if sqlite commit fails.
-  bool SaveEntryToDB(const EntryKernel& entry);
-  bool SaveNewEntryToDB(const EntryKernel& entry);
-  bool UpdateEntryToDB(const EntryKernel& entry);
-
-  DirOpenResult DoLoad(MetahandlesIndex* entry_bucket,
-      Directory::KernelLoadInfo* kernel_load_info);
-
-  // Close save_dbhandle_.  Broken out for testing.
-  void EndSave();
-
-  // Removes each entry whose metahandle is in |handles| from the database.
-  // Does synchronous I/O.  Returns false on error.
-  bool DeleteEntries(const MetahandleSet& handles);
-
-  // Drop all tables in preparation for reinitialization.
-  void DropAllTables();
-
-  // Serialization helpers for syncable::ModelType.  These convert between
-  // the ModelType enum and the values we persist in the database to identify
-  // a model.  We persist a default instance of the specifics protobuf as the
-  // ID, rather than the enum value.
-  static ModelType ModelIdToModelTypeEnum(const void* data, int length);
-  static std::string ModelTypeEnumToModelId(ModelType model_type);
-
-  static std::string GenerateCacheGUID();
-
-  // Runs an integrity check on the current database.  If the
-  // integrity check fails, false is returned and error is populated
-  // with an error message.
-  bool CheckIntegrity(sqlite3* handle, std::string* error) const;
-
-  // Migration utilities.
-  bool RefreshColumns();
-  bool SetVersion(int version);
-  int GetVersion();
-
-  bool MigrateToSpecifics(const char* old_columns,
-                          const char* specifics_column,
-                          void(*handler_function) (
-                              sql::Statement* old_value_query,
-                              int old_value_column,
-                              sync_pb::EntitySpecifics* mutable_new_value));
-
-  // Individual version migrations.
-  bool MigrateVersion67To68();
-  bool MigrateVersion68To69();
-  bool MigrateVersion69To70();
-  bool MigrateVersion70To71();
-  bool MigrateVersion71To72();
-  bool MigrateVersion72To73();
-  bool MigrateVersion73To74();
-  bool MigrateVersion74To75();
-  bool MigrateVersion75To76();
-  bool MigrateVersion76To77();
-  bool MigrateVersion77To78();
-
-  scoped_ptr<sql::Connection> db_;
-  sql::Statement save_entry_statement_;
-  std::string dir_name_;
-
-  // Set to true if migration left some old columns around that need to be
-  // discarded.
-  bool needs_column_refresh_;
-
-  DISALLOW_COPY_AND_ASSIGN(DirectoryBackingStore);
-};
-
-}  // namespace syncable
-
-#endif  // CHROME_BROWSER_SYNC_SYNCABLE_DIRECTORY_BACKING_STORE_H_