sync/engine/conflict_util.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "sync/engine/conflict_util.h"
   6
   7 #include "sync/syncable/mutable_entry.h"
   8
   9 namespace syncer {
  10
  11 using syncable::BASE_VERSION;
  12 using syncable::IS_UNAPPLIED_UPDATE;
  13 using syncable::IS_UNSYNCED;
  14 using syncable::SERVER_VERSION;
  15
  16 using syncable::MutableEntry;
  17
  18 // Allow the server's changes to take precedence.
  19 // This will take effect during the next ApplyUpdates step.
  20 void IgnoreLocalChanges(MutableEntry* entry) {
  21   DCHECK(entry->Get(IS_UNSYNCED));
  22   DCHECK(entry->Get(IS_UNAPPLIED_UPDATE));
  23   entry->Put(IS_UNSYNCED, false);
  24 }
  25
  26 // Overwrite the server with our own value.
  27 // We will commit our local data, overwriting the server, at the next
  28 // opportunity.
  29 void OverwriteServerChanges(MutableEntry* entry) {
  30   DCHECK(entry->Get(IS_UNSYNCED));
  31   DCHECK(entry->Get(IS_UNAPPLIED_UPDATE));
  32   entry->Put(BASE_VERSION, entry->Get(SERVER_VERSION));
  33   entry->Put(IS_UNAPPLIED_UPDATE, false);
  34 }
  35
  36 // Having determined that everything matches, we ignore the non-conflict.
  37 void IgnoreConflict(MutableEntry* entry) {
  38   // If we didn't also unset IS_UNAPPLIED_UPDATE, then we would lose unsynced
  39   // positional data from adjacent entries when the server update gets applied
  40   // and the item is re-inserted into the PREV_ID/NEXT_ID linked list. This is
  41   // primarily an issue because we commit after applying updates, and is most
  42   // commonly seen when positional changes are made while a passphrase is
  43   // required (and hence there will be many encryption conflicts).
  44   DCHECK(entry->Get(IS_UNSYNCED));
  45   DCHECK(entry->Get(IS_UNAPPLIED_UPDATE));
  46   entry->Put(BASE_VERSION, entry->Get(SERVER_VERSION));
  47   entry->Put(IS_UNAPPLIED_UPDATE, false);
  48   entry->Put(IS_UNSYNCED, false);
  49 }
  50
  51 }  // namespace syncer