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

webkit/dom_storage/dom_storage_host.cc

 // Copyright (c) 2012 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 "webkit/dom_storage/dom_storage_host.h"
 
 #include "googleurl/src/gurl.h"
 #include "webkit/dom_storage/dom_storage_area.h"
 #include "webkit/dom_storage/dom_storage_context.h"
 #include "webkit/dom_storage/dom_storage_namespace.h"
@@ skipping 43 matching lines @@
 bool DomStorageHost::ExtractAreaValues(
     int connection_id, ValuesMap* map) {
   map->clear();
   DomStorageArea* area = GetOpenArea(connection_id);
   if (!area) {
     // TODO(michaeln): Fix crbug/134003 and return false here.
     // Until then return true to avoid crashing the renderer
     // for sending a bad message.
     return true;
   }
+  if (!area->IsLoadedInMemory()) {
+    DomStorageNamespace* ns = GetNamespace(connection_id);
+    DCHECK(ns);
+    if (ns->CountInMemoryAreas() > kMaxInMemoryAreas) {
+      ns->PurgeMemory(DomStorageNamespace::PURGE_UNOPENED);
+      if (ns->CountInMemoryAreas() > kMaxInMemoryAreas)
+        ns->PurgeMemory(DomStorageNamespace::PURGE_AGGRESSIVE);
+    }
+  }
   area->ExtractValues(map);
   return true;
 }
 
 unsigned DomStorageHost::GetAreaLength(int connection_id) {
   DomStorageArea* area = GetOpenArea(connection_id);
   if (!area)
     return 0;
   return area->Length();
 }
@@ skipping 65 matching lines @@
   return false;
 }
 
 DomStorageArea* DomStorageHost::GetOpenArea(int connection_id) {
   AreaMap::iterator found = connections_.find(connection_id);
   if (found == connections_.end())
     return NULL;
   return found->second.area_;
 }
 
+DomStorageNamespace* DomStorageHost::GetNamespace(int connection_id) {
+  AreaMap::iterator found = connections_.find(connection_id);
+  if (found == connections_.end())
+    return NULL;
+  return found->second.namespace_;
+}
+
 // NamespaceAndArea
 
 DomStorageHost::NamespaceAndArea::NamespaceAndArea() {}
 DomStorageHost::NamespaceAndArea::~NamespaceAndArea() {}
 
 }  // namespace dom_storage