[Sync] Don't commit items with predecessors/parents in conflict.

chrome/browser/sync/engine/get_commit_ids_command.h

 // Copyright (c) 2011 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_ENGINE_GET_COMMIT_IDS_COMMAND_H_
 #define CHROME_BROWSER_SYNC_ENGINE_GET_COMMIT_IDS_COMMAND_H_
 #pragma once
 
 #include <utility>
 #include <vector>
@@ skipping 111 matching lines @@
 
   void AddUncommittedParentsAndTheirPredecessors(
       syncable::BaseTransaction* trans,
       syncable::Id parent_id,
       const ModelSafeRoutingInfo& routes,
       syncable::ModelTypeSet throttled_types);
 
   // OrderedCommitSet helpers for adding predecessors in order.
   // TODO(ncarter): Refactor these so that the |result| parameter goes away,
   // and AddItem doesn't need to consider two OrderedCommitSets.
+
+  // Adds |item| to |result| if it's ready for committing and was not already
+  // present. If |item| was added, returns true. If item already existed,
+  // returns false. If item was not ready for commit, clears |result| and

[akalin, 2011/12/15 01:58:20]

Is there a reason for the 'clear results' action on false?  It seems like the
caller of this function eventually discards the OrderedCommitSet anyway.

+  // returns false.
   bool AddItem(syncable::Entry* item,
                syncable::ModelTypeSet throttled_types,
                sessions::OrderedCommitSet* result);
+  // Adds item and all it's unsynced predecessors to |result| if all that are
+  // unsynced are ready for commit. If either item or any of it's predecessors
+  // are unsynced but not ready for commit, clears |result|.
+  // Return values:
+  //   True: if unsynced items were added to |result| and processing of this set
+  //         should continue.
+  //   False: if processing of the set should not continue, either because not
+  //          all unsynced items were ready for commit or the items are already
+  //          present in |result|.
   bool AddItemThenPredecessors(syncable::BaseTransaction* trans,
                                syncable::ModelTypeSet throttled_types,
                                syncable::Entry* item,
-                               syncable::IndexedBitField inclusion_filter,
                                sessions::OrderedCommitSet* result);
+  // Appends all unsynced predecessors of |item|, followed by |item| iteself,

[akalin, 2011/12/14 03:39:52]

iteself -> itself

+  // to |ordered_commit_set_|, iff item and all its unsynced predecessors
+  // are ready for commit. If |item| or any of it's unsynced predecessors
+  // are unready for commit, does not modify |ordered_commit_set_|.

[akalin, 2011/12/14 03:39:52]

unready -> not ready

   void AddPredecessorsThenItem(syncable::BaseTransaction* trans,
                                syncable::ModelTypeSet throttled_types,
                                syncable::Entry* item,
-                               syncable::IndexedBitField inclusion_filter,
                                const ModelSafeRoutingInfo& routes);
 
   bool IsCommitBatchFull();
 
   void AddCreatesAndMoves(const vector<int64>& unsynced_handles,
                           syncable::WriteTransaction* write_transaction,
                           const ModelSafeRoutingInfo& routes,
                           syncable::ModelTypeSet throttled_types);
 
   void AddDeletes(const vector<int64>& unsynced_handles,
                   syncable::WriteTransaction* write_transaction);
 
   scoped_ptr<sessions::OrderedCommitSet> ordered_commit_set_;
 
   int requested_commit_batch_size_;
   bool passphrase_missing_;
   syncable::ModelTypeSet encrypted_types_;
 
   DISALLOW_COPY_AND_ASSIGN(GetCommitIdsCommand);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_ENGINE_GET_COMMIT_IDS_COMMAND_H_