Purge in-memory localStorage areas if the # of areas exceeds the limit

webkit/dom_storage/dom_storage_context.cc

Index: webkit/dom_storage/dom_storage_context.cc
diff --git a/webkit/dom_storage/dom_storage_context.cc b/webkit/dom_storage/dom_storage_context.cc
index 45aae747639668a2513e63450d27ca46a8f0064e..170c58383258c98523f8b35a7d7e724355d5b48a 100644
--- a/webkit/dom_storage/dom_storage_context.cc
+++ b/webkit/dom_storage/dom_storage_context.cc
@@ -352,6 +352,28 @@ void DomStorageContext::StartScavengingUnusedSessionStorage() {
   }
 }
 
+int64 DomStorageContext::GetInMemoryStorageSize() const {
+  // TODO(kinuko): Cache this!!
+  int64 total_size = 0;
+  // Naively add-up the area size for each connection.
+  std::set<DomStorageArea*> visited_areas;
+  for (StorageNamespaceMap::const_iterator itr = namespaces_.begin();
+       itr != namespaces_.end(); ++itr) {
+    const DomStorageNamespace::AreaMap& map = itr->second->GetAreaMap();
+    for (DomStorageNamespace::AreaMap::const_iterator map_itr = map.begin();
+         map_itr != map.end(); ++map_itr) {
+      // We don't care open_count_ here, since we want to limit the
+      // memory usage.
+      DomStorageArea* area = map_itr->second.area_;
+      DCHECK(area);
+      if (visited_areas.insert(area).second) {
+        total_size += area->GetMapSize();
+      }
+    }
+  }
+  return total_size;
+}
+
 void DomStorageContext::FindUnusedNamespaces() {
   DCHECK(session_storage_database_.get());
   if (scavenging_started_)