First-time sync: asymptotic running time improvement

chrome/browser/sync/engine/syncer_util.h

 // 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_
 #pragma once
@@ skipping 83 matching lines @@
                                               const bool deleted,
                                               const bool is_directory,
                                               syncable::ModelType model_type);
 
   // Assumes we have an existing entry; verify an update that seems to be
   // expressing an 'undelete'
   static VerifyResult VerifyUndelete(syncable::WriteTransaction* trans,
                                      const SyncEntity& update,
                                      syncable::MutableEntry* target);
 
-  // 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(
@@ skipping 65 matching lines @@
 
 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_