sync: Loop committing items without downloading updates (v2)

sync/engine/get_commit_ids_command.cc

Index: sync/engine/get_commit_ids_command.cc
diff --git a/sync/engine/get_commit_ids_command.cc b/sync/engine/get_commit_ids_command.cc
index 55d7e232b12941228f9e9108bdae0f58148da53e..1b0129cd2621f5c9b1e17dd158546db1958fad63 100644
--- a/sync/engine/get_commit_ids_command.cc
+++ b/sync/engine/get_commit_ids_command.cc
@@ -22,8 +22,12 @@ using sessions::OrderedCommitSet;
 using sessions::SyncSession;
 using sessions::StatusController;
 
-GetCommitIdsCommand::GetCommitIdsCommand(int commit_batch_size)
-    : requested_commit_batch_size_(commit_batch_size) {}
+GetCommitIdsCommand::GetCommitIdsCommand(
+    const size_t commit_batch_size,
+    sessions::OrderedCommitSet* commit_set)
+    : requested_commit_batch_size_(commit_batch_size),
+      commit_set_(commit_set) {
+}
 
 GetCommitIdsCommand::~GetCommitIdsCommand() {}
 
@@ -61,17 +65,12 @@ SyncerError GetCommitIdsCommand::ExecuteImpl(SyncSession* session) {
                  session->routing_info(),
                  ready_unsynced_set);
 
-  StatusController* status = session->mutable_status_controller();
-  syncable::Directory::UnsyncedMetaHandles ready_unsynced_vector(
-      ready_unsynced_set.begin(), ready_unsynced_set.end());
-  status->set_unsynced_handles(ready_unsynced_vector);
   const vector<syncable::Id>& verified_commit_ids =
-      ordered_commit_set_->GetAllCommitIds();
+      commit_set_->GetAllCommitIds();
 
   for (size_t i = 0; i < verified_commit_ids.size(); i++)
     DVLOG(1) << "Debug commit batch result:" << verified_commit_ids[i];
 
-  status->set_commit_set(*ordered_commit_set_.get());
   return SYNCER_OK;
 }
 
@@ -188,7 +187,7 @@ bool GetCommitIdsCommand::AddUncommittedParentsAndTheirPredecessors(
     syncable::Entry parent(trans, syncable::GET_BY_ID, parent_id);
     CHECK(parent.good()) << "Bad user-only parent in item path.";
     int64 handle = parent.Get(syncable::META_HANDLE);
-    if (ordered_commit_set_->HaveCommitItem(handle)) {
+    if (commit_set_->HaveCommitItem(handle)) {
       // We've already added this parent (and therefore all of its parents).
       // We can return early.
       break;
@@ -196,7 +195,7 @@ bool GetCommitIdsCommand::AddUncommittedParentsAndTheirPredecessors(
     if (!AddItemThenPredecessors(trans, ready_unsynced_set, parent,
                                  &item_dependencies)) {
       // There was a parent/predecessor in conflict. We return without adding
-      // anything to |ordered_commit_set_|.
+      // anything to |commit_set|.
       DVLOG(1) << "Parent or parent's predecessor was in conflict, omitting "
                << item;
       return false;
@@ -234,7 +233,7 @@ bool GetCommitIdsCommand::AddItemThenPredecessors(
     const syncable::Entry& item,
     OrderedCommitSet* result) const {
   int64 item_handle = item.Get(syncable::META_HANDLE);
-  if (ordered_commit_set_->HaveCommitItem(item_handle)) {
+  if (commit_set_->HaveCommitItem(item_handle)) {
     // We've already added this item to the commit set, and so must have
     // already added the predecessors as well.
     return true;
@@ -251,7 +250,7 @@ bool GetCommitIdsCommand::AddItemThenPredecessors(
     if (!prev.Get(syncable::IS_UNSYNCED))
       break;
     int64 handle = prev.Get(syncable::META_HANDLE);
-    if (ordered_commit_set_->HaveCommitItem(handle)) {
+    if (commit_set_->HaveCommitItem(handle)) {
       // We've already added this item to the commit set, and so must have
       // already added the predecessors as well.
       return true;
@@ -284,7 +283,7 @@ bool GetCommitIdsCommand::AddPredecessorsThenItem(
 }
 
 bool GetCommitIdsCommand::IsCommitBatchFull() const {
-  return ordered_commit_set_->Size() >= requested_commit_batch_size_;
+  return commit_set_->Size() >= requested_commit_batch_size_;
 }
 
 void GetCommitIdsCommand::AddCreatesAndMoves(
@@ -295,7 +294,7 @@ void GetCommitIdsCommand::AddCreatesAndMoves(
   for (std::set<int64>::const_iterator iter = ready_unsynced_set.begin();
        !IsCommitBatchFull() && iter != ready_unsynced_set.end(); ++iter) {
     int64 metahandle = *iter;
-    if (ordered_commit_set_->HaveCommitItem(metahandle))
+    if (commit_set_->HaveCommitItem(metahandle))
       continue;
 
     syncable::Entry entry(write_transaction,
@@ -316,14 +315,14 @@ void GetCommitIdsCommand::AddCreatesAndMoves(
                                   ready_unsynced_set,
                                   entry,
                                   &item_dependencies)) {
-        ordered_commit_set_->Append(item_dependencies);
+        commit_set_->Append(item_dependencies);
       }
     }
   }
 
   // It's possible that we overcommitted while trying to expand dependent
   // items.  If so, truncate the set down to the allowed size.
-  ordered_commit_set_->Truncate(requested_commit_batch_size_);
+  commit_set_->Truncate(requested_commit_batch_size_);
 }
 
 void GetCommitIdsCommand::AddDeletes(
@@ -334,7 +333,7 @@ void GetCommitIdsCommand::AddDeletes(
   for (std::set<int64>::const_iterator iter = ready_unsynced_set.begin();
        !IsCommitBatchFull() && iter != ready_unsynced_set.end(); ++iter) {
     int64 metahandle = *iter;
-    if (ordered_commit_set_->HaveCommitItem(metahandle))
+    if (commit_set_->HaveCommitItem(metahandle))
       continue;
 
     syncable::Entry entry(write_transaction, syncable::GET_BY_HANDLE,
@@ -365,7 +364,7 @@ void GetCommitIdsCommand::AddDeletes(
           DVLOG(1) << "Inserting moved and deleted entry, will be missed by "
                    << "delete roll." << entry.Get(syncable::ID);
 
-          ordered_commit_set_->AddCommitItem(metahandle,
+          commit_set_->AddCommitItem(metahandle,
               entry.Get(syncable::ID),
               entry.GetModelType());
         }
@@ -396,14 +395,14 @@ void GetCommitIdsCommand::AddDeletes(
   for (std::set<int64>::const_iterator iter = ready_unsynced_set.begin();
        !IsCommitBatchFull() && iter != ready_unsynced_set.end(); ++iter) {
     int64 metahandle = *iter;
-    if (ordered_commit_set_->HaveCommitItem(metahandle))
+    if (commit_set_->HaveCommitItem(metahandle))
       continue;
     syncable::MutableEntry entry(write_transaction, syncable::GET_BY_HANDLE,
                                  metahandle);
     if (entry.Get(syncable::IS_DEL)) {
       syncable::Id parent_id = entry.Get(syncable::PARENT_ID);
       if (legal_delete_parents.count(parent_id)) {
-        ordered_commit_set_->AddCommitItem(metahandle, entry.Get(syncable::ID),
+        commit_set_->AddCommitItem(metahandle, entry.Get(syncable::ID),
             entry.GetModelType());
       }
     }
@@ -414,7 +413,6 @@ void GetCommitIdsCommand::BuildCommitIds(
     syncable::WriteTransaction* write_transaction,
     const ModelSafeRoutingInfo& routes,
     const std::set<int64>& ready_unsynced_set) {
-  ordered_commit_set_.reset(new OrderedCommitSet(routes));
   // Commits follow these rules:
   // 1. Moves or creates are preceded by needed folder creates, from
   //    root to leaf.  For folders whose contents are ordered, moves