[Sync] Speed up Javascript node operations

chrome/browser/sync/engine/syncapi.cc

 // 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.
 
 #include "chrome/browser/sync/engine/syncapi.h"
 
 #include <algorithm>
 #include <bitset>
 #include <iomanip>
 #include <list>
@@ skipping 1530 matching lines @@
   // 'using_explicit_passphrase' in the NigoriSpecifics.
   // TODO(tim): Bug 62103.  Remove this after it has been pushed out to dev
   // channel users.
   void SetUsingExplicitPassphrasePrefForMigration(
       WriteTransaction* const trans);
 
   // Checks for server reachabilty and requests a nudge.
   void OnIPAddressChangedImpl();
 
   // Functions called by ProcessMessage().
-  browser_sync::JsArgList ProcessGetNodeByIdMessage(
+  browser_sync::JsArgList ProcessGetNodesByIdMessage(
+      const browser_sync::JsArgList& args);
+
+  browser_sync::JsArgList ProcessGetChildNodeIdsMessage(
       const browser_sync::JsArgList& args);
 
   browser_sync::JsArgList ProcessFindNodesContainingString(
       const browser_sync::JsArgList& args);
 
   // We couple the DirectoryManager and username together in a UserShare member
   // so we can return a handle to share_ to clients of the API for use when
   // constructing any transaction type.
   UserShare share_;
 
@@ skipping 1143 matching lines @@
       LogNoRouter(name, args);
       return;
     }
     ReadTransaction trans(GetUserShare());
     ReadNode root(&trans);
     root.InitByRootLookup();
     ListValue return_args;
     return_args.Append(root.ToValue());
     parent_router_->RouteJsMessageReply(
         name, browser_sync::JsArgList(&return_args), sender);
-  } else if (name == "getNodeById") {
+  } else if (name == "getNodesById") {
     if (!parent_router_) {
       LogNoRouter(name, args);
       return;
     }
     parent_router_->RouteJsMessageReply(
-        name, ProcessGetNodeByIdMessage(args), sender);
+        name, ProcessGetNodesByIdMessage(args), sender);
+  } else if (name == "getChildNodeIds") {
+    if (!parent_router_) {
+      LogNoRouter(name, args);
+      return;
+    }
+    parent_router_->RouteJsMessageReply(
+        name, ProcessGetChildNodeIdsMessage(args), sender);
   } else if (name == "findNodesContainingString") {
     if (!parent_router_) {
       LogNoRouter(name, args);
       return;
     }
     parent_router_->RouteJsMessageReply(
         name, ProcessFindNodesContainingString(args), sender);
   } else {
     VLOG(1) << "Dropping unknown message " << name
               << " with args " << args.ToString();
@@ skipping 12 matching lines @@
 void SyncManager::SyncInternal::RouteJsMessageReply(
       const std::string& name,
       const browser_sync::JsArgList& args,
       const browser_sync::JsEventHandler* target) {
   if (!parent_router_) {
     return;
   }
   parent_router_->RouteJsMessageReply(name, args, target);
 }
 
-browser_sync::JsArgList SyncManager::SyncInternal::ProcessGetNodeByIdMessage(
+namespace {
+
+bool GetId(const ListValue& ids, int i, int64* id) {
+  std::string id_str;
+  if (!ids.GetString(i, &id_str)) {
+    return false;
+  }
+  if (!base::StringToInt64(id_str, id)) {
+    return false;
+  }
+  if (*id == kInvalidId) {
+    return false;
+  }
+  return true;
+}
+
+}  // namespace
+
+browser_sync::JsArgList SyncManager::SyncInternal::ProcessGetNodesByIdMessage(
     const browser_sync::JsArgList& args) {
-  ListValue null_return_args_list;
-  null_return_args_list.Append(Value::CreateNullValue());
-  browser_sync::JsArgList null_return_args(&null_return_args_list);
-  std::string id_str;
-  if (!args.Get().GetString(0, &id_str)) {
-    return null_return_args;
+  ListValue return_args;
+  ListValue* nodes = new ListValue();
+  return_args.Append(nodes);
+  ListValue* id_list = NULL;
+  ReadTransaction trans(GetUserShare());
+  if (args.Get().GetList(0, &id_list)) {
+    for (size_t i = 0; i < id_list->GetSize(); ++i) {
+      int64 id = kInvalidId;
+      if (!GetId(*id_list, i, &id)) {
+        continue;
+      }
+      ReadNode node(&trans);
+      if (!node.InitByIdLookup(id)) {
+        continue;
+      }
+      nodes->Append(node.ToValue());
+    }
   }
-  int64 id;
-  if (!base::StringToInt64(id_str, &id)) {
-    return null_return_args;
-  }
-  if (id == kInvalidId) {
-    return null_return_args;
-  }
-  ReadTransaction trans(GetUserShare());
-  ReadNode node(&trans);
-  if (!node.InitByIdLookup(id)) {
-    return null_return_args;
-  }
-  ListValue return_args;
-  return_args.Append(node.ToValue());
   return browser_sync::JsArgList(&return_args);
 }
 
+browser_sync::JsArgList SyncManager::SyncInternal::
+    ProcessGetChildNodeIdsMessage(
+        const browser_sync::JsArgList& args) {
+  ListValue return_args;
+  ListValue* child_ids = new ListValue();
+  return_args.Append(child_ids);
+  int64 id = kInvalidId;
+  if (GetId(args.Get(), 0, &id)) {
+    ReadTransaction trans(GetUserShare());
+    ReadNode node(&trans);
+    if (node.InitByIdLookup(id)) {
+      int64 child_id = node.GetFirstChildId();
+      while (child_id != kInvalidId) {
+        ReadNode child_node(&trans);
+        if (!child_node.InitByIdLookup(child_id)) {
+          break;
+        }
+        child_ids->Append(Value::CreateStringValue(
+            base::Int64ToString(child_id)));
+        child_id = child_node.GetSuccessorId();
+      }
+    }
+  }
+  return browser_sync::JsArgList(&return_args);
+}
+
 browser_sync::JsArgList SyncManager::SyncInternal::
     ProcessFindNodesContainingString(
     const browser_sync::JsArgList& args) {
   std::string query;
   ListValue return_args;
   if (!args.Get().GetString(0, &query)) {
     return_args.Append(new ListValue());
     return browser_sync::JsArgList(&return_args);
   }
 
@@ skipping 161 matching lines @@
 void SyncManager::TriggerOnIncomingNotificationForTest(
     const syncable::ModelTypeBitSet& model_types) {
   syncable::ModelTypePayloadMap model_types_with_payloads =
       syncable::ModelTypePayloadMapFromBitSet(model_types,
           std::string());
 
   data_->OnIncomingNotification(model_types_with_payloads);
 }
 
 }  // namespace sync_api