Initial commit of sync engine code to browser/sync.

The code is not built on any platform yet.  That will arrive
as a subsequent checkin.

This is an implementation of the interface exposed earlier
through syncapi.h.  It is the client side of a sync
protocol that lets users sync their browser data
(currently, just bookmarks) with their Google Account.

Table of contents:

browser/sync/
  protocol - The protocol definition, and
             other definitions necessary to connect to
             the service.
  syncable/ - defines a data model for syncable objects,
              and provides a sqlite-based backing store
              for this model.
  engine/ - includes the core sync logic, including commiting
            changes to the server, downloading changes from
            the server, resolving conflicts, other parts of
            the sync algorithm.
  engine/net - parts of the sync engine focused on the
               business of talking to the server.  Some of
               this is binds a generic "server connection"
               interface to a concrete implementation
               provided by Chromium.
  notifier - the part of the syncer focused on the business
             of sending and receiving xmpp notifications.
             Notifications are used instead of polling to
             achieve very low latency change propagation.
  util - not necessarily sync specific utility code.  Much
         of this is scaffolding which should either be
         replaced by, or merged with, the utility code
         in base/.

BUG=none
TEST=this code includes its own suite of unit tests.

Review URL: http://codereview.chromium.org/194065

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@25850 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 206 insertions, 0 deletions

diff --git a/chrome/browser/sync/engine/syncer_util.h b/chrome/browser/sync/engine/syncer_util.h
new file mode 100644
index 0000000..91e0c814
--- /dev/null
+++ b/chrome/browser/sync/engine/syncer_util.h
@@ -0,0 +1,206 @@
+// Copyright (c) 2006-2008 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.
+
+// Utility functions manipulating syncable::Entries, intended for use by
+// the syncer.
+
+#ifndef CHROME_BROWSER_SYNC_ENGINE_SYNCER_UTIL_H_
+#define CHROME_BROWSER_SYNC_ENGINE_SYNCER_UTIL_H_
+
+#include <set>
+#include <string>
+#include <vector>
+
+#include "chrome/browser/sync/engine/syncer.h"
+#include "chrome/browser/sync/engine/syncer_types.h"
+#include "chrome/browser/sync/syncable/syncable_id.h"
+#include "chrome/browser/sync/syncable/syncable.h"
+#include "chrome/browser/sync/util/path_helpers.h"
+#include "chrome/browser/sync/util/sync_types.h"
+
+namespace browser_sync {
+
+class SyncerSession;
+class SyncEntity;
+
+
+class SyncerUtil {
+ public:
+  // TODO(ncarter): Remove unique-in-parent title support and name conflicts.
+  static syncable::Id GetNameConflictingItemId(
+      syncable::BaseTransaction* trans,
+      const syncable::Id& parent_id,
+      const PathString& server_name);
+
+  static void ChangeEntryIDAndUpdateChildren(
+      syncable::WriteTransaction* trans,
+      syncable::MutableEntry* entry,
+      const syncable::Id& new_id,
+      syncable::Directory::ChildHandles* children);
+
+  // Returns the number of unsynced entries.
+  static int GetUnsyncedEntries(syncable::BaseTransaction* trans,
+                                std::vector<int64> *handles);
+
+  static void ChangeEntryIDAndUpdateChildren(syncable::WriteTransaction* trans,
+                                             syncable::MutableEntry* entry,
+                                             const syncable::Id& new_id);
+
+  static void AttemptReuniteLostCommitResponses(
+      syncable::WriteTransaction* trans,
+      const SyncEntity& server_entry,
+      const std::string& client_id);
+
+  static UpdateAttemptResponse AttemptToUpdateEntry(
+      syncable::WriteTransaction* const trans,
+      syncable::MutableEntry* const entry,
+      SyncerSession* const session);
+
+  static UpdateAttemptResponse AttemptToUpdateEntryWithoutMerge(
+      syncable::WriteTransaction* const trans,
+      syncable::MutableEntry* const entry,
+      SyncerSession* const session, syncable::Id* const conflicting_id);
+
+  // Pass in name to avoid redundant UTF8 conversion.
+  static void UpdateServerFieldsFromUpdate(
+      syncable::MutableEntry* local_entry,
+      const SyncEntity& server_entry,
+      const syncable::SyncName& name);
+
+  static void ApplyExtendedAttributes(
+      syncable::MutableEntry* local_entry,
+      const SyncEntity& server_entry);
+
+  // Creates a new Entry iff no Entry exists with the given id.
+  static void CreateNewEntry(syncable::WriteTransaction *trans,
+                             const syncable::Id& id);
+
+  static bool ServerAndLocalEntriesMatch(syncable::Entry* entry);
+
+  static void SplitServerInformationIntoNewEntry(
+      syncable::WriteTransaction* trans,
+      syncable::MutableEntry* entry);
+
+  // This function is called on an entry when we can update the user-facing data
+  // from the server data.
+  static void UpdateLocalDataFromServerData(syncable::WriteTransaction* trans,
+                                            syncable::MutableEntry* entry);
+
+  static VerifyCommitResult ValidateCommitEntry(syncable::MutableEntry* entry);
+
+  static VerifyResult VerifyNewEntry(const SyncEntity& entry,
+                                     syncable::MutableEntry* same_id,
+                                     const bool deleted);
+
+  // Assumes we have an existing entry; check here for updates that break
+  // consistency rules.
+  static VerifyResult VerifyUpdateConsistency(syncable::WriteTransaction* trans,
+                                              const SyncEntity& entry,
+                                              syncable::MutableEntry* same_id,
+                                              const bool deleted,
+                                              const bool is_directory,
+                                              const bool is_bookmark);
+
+  // Assumes we have an existing entry; verify an update that seems to be
+  // expressing an 'undelete'
+  static VerifyResult VerifyUndelete(syncable::WriteTransaction* trans,
+                                     const SyncEntity& entry,
+                                     syncable::MutableEntry* same_id);
+
+  // Compute a local predecessor position for |update_item|.  The position
+  // is determined by the SERVER_POSITION_IN_PARENT value of |update_item|,
+  // as well as the SERVER_POSITION_IN_PARENT values of any up-to-date
+  // children of |parent_id|.
+  static syncable::Id ComputePrevIdFromServerPosition(
+      syncable::BaseTransaction* trans,
+      syncable::Entry* update_item,
+      const syncable::Id& parent_id);
+
+  // Append |item|, followed by a chain of its predecessors selected by
+  // |inclusion_filter|, to the |commit_ids| vector and tag them as included by
+  // storing in the set |inserted_items|.  |inclusion_filter| (typically one of
+  // IS_UNAPPLIED_UPDATE or IS_UNSYNCED) selects which type of predecessors to
+  // include.  Returns true if |item| was added, and false if it was already in
+  // the list.
+  //
+  // Use AddPredecessorsThenItem instead of this method if you want the
+  // item to be the last, rather than first, item appended.
+  static bool AddItemThenPredecessors(
+      syncable::BaseTransaction* trans,
+      syncable::Entry* item,
+      syncable::IndexedBitField inclusion_filter,
+      syncable::MetahandleSet* inserted_items,
+      std::vector<syncable::Id>* commit_ids);
+
+  // Exactly like AddItemThenPredecessors, except items are appended in the
+  // reverse (and generally more useful) order: a chain of predecessors from
+  // far to near, and finally the item.
+  static void AddPredecessorsThenItem(
+      syncable::BaseTransaction* trans,
+      syncable::Entry* item,
+      syncable::IndexedBitField inclusion_filter,
+      syncable::MetahandleSet* inserted_items,
+      std::vector<syncable::Id>* commit_ids);
+
+  static void AddUncommittedParentsAndTheirPredecessors(
+      syncable::BaseTransaction* trans,
+      syncable::MetahandleSet* inserted_items,
+      std::vector<syncable::Id>* commit_ids,
+      syncable::Id parent_id);
+
+  static void MarkDeletedChildrenSynced(
+      const syncable::ScopedDirLookup &dir,
+      std::set<syncable::Id>* deleted_folders);
+
+  // Examine the up-to-date predecessors of this item according to the server
+  // position, and then again according to the local position.  Return true
+  // if they match.  For an up-to-date item, this should be the case.
+  static bool ServerAndLocalOrdersMatch(syncable::Entry* entry);
+
+ private:
+  // Private ctor/dtor since this class shouldn't be instantiated.
+  SyncerUtil() {}
+  virtual ~SyncerUtil() {}
+  DISALLOW_COPY_AND_ASSIGN(SyncerUtil);
+};
+
+#ifndef OS_WINDOWS
+
+// time.h on Linux and Mac both return seconds since the epoch, this should
+// be converted to milliseconds.
+inline int64 ServerTimeToClientTime(int64 server_time) {
+  return server_time / GG_LONGLONG(1000);
+}
+
+inline int64 ClientTimeToServerTime(int64 client_time) {
+  return client_time * GG_LONGLONG(1000);
+}
+
+// As we truncate server times on the client for posix and on the server for
+// windows we need two ClientAndServerTimeMatch fucntions.
+inline bool ClientAndServerTimeMatch(int64 client_time, int64 server_time) {
+  // Compare at the coarser timescale (client)
+  return client_time == ServerTimeToClientTime(server_time);
+}
+#else
+// The sync server uses Java Times (ms since 1970)
+// and the client uses FILETIMEs (ns since 1601) so we need to convert
+// between the timescales.
+inline int64 ServerTimeToClientTime(int64 server_time) {
+  return server_time * GG_LONGLONG(10000) + GG_LONGLONG(116444736000000000);
+}
+
+inline int64 ClientTimeToServerTime(int64 client_time) {
+  return (client_time - GG_LONGLONG(116444736000000000)) / GG_LONGLONG(10000);
+}
+
+inline bool ClientAndServerTimeMatch(int64 client_time, int64 server_time) {
+  // Compare at the coarser timescale (server)
+  return ClientTimeToServerTime(client_time) == server_time;
+}
+#endif
+
+}  // namespace browser_sync
+
+#endif  // CHROME_BROWSER_SYNC_ENGINE_SYNCER_UTIL_H_