Switch to using the async DomStorage IPC messages and add a caching layer …

content/renderer/dom_storage/webstoragearea_impl.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 "content/renderer/dom_storage/webstoragearea_impl.h"
 
 #include "base/lazy_instance.h"
 #include "base/metrics/histogram.h"
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
 #include "content/common/dom_storage_messages.h"
+#include "content/renderer/dom_storage/dom_storage_dispatcher.h"
 #include "content/renderer/render_thread_impl.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebURL.h"
-#include "webkit/dom_storage/dom_storage_types.h"
+#include "webkit/dom_storage/dom_storage_cached_area.h"
 
+using dom_storage::DomStorageCachedArea;
 using WebKit::WebString;
 using WebKit::WebURL;
 
+namespace {
 typedef IDMap<WebStorageAreaImpl> AreaImplMap;
-
-static base::LazyInstance<AreaImplMap>::Leaky
+base::LazyInstance<AreaImplMap>::Leaky
     g_all_areas_map = LAZY_INSTANCE_INITIALIZER;
 
+DomStorageDispatcher* dispatcher() {
+  return RenderThreadImpl::current()->dom_storage_dispatcher();
+}
+}  // namespace
+
 // static
-WebStorageAreaImpl* WebStorageAreaImpl::FromConnectionId(
-    int id) {
+WebStorageAreaImpl* WebStorageAreaImpl::FromConnectionId(int id) {
   return g_all_areas_map.Pointer()->Lookup(id);
 }
 
 WebStorageAreaImpl::WebStorageAreaImpl(
     int64 namespace_id, const GURL& origin)
     : ALLOW_THIS_IN_INITIALIZER_LIST(
-          connection_id_(g_all_areas_map.Pointer()->Add(this))) {
-  DCHECK(connection_id_);
-  RenderThreadImpl::current()->Send(
-      new DOMStorageHostMsg_OpenStorageArea(
-          connection_id_, namespace_id, origin));
+          connection_id_(g_all_areas_map.Pointer()->Add(this))),
+      cached_area_(dispatcher()->
+          OpenCachedArea(connection_id_, namespace_id, origin)) {
 }
 
 WebStorageAreaImpl::~WebStorageAreaImpl() {
   g_all_areas_map.Pointer()->Remove(connection_id_);
-  RenderThreadImpl::current()->Send(
-      new DOMStorageHostMsg_CloseStorageArea(connection_id_));
+  if (dispatcher())
+    dispatcher()->CloseCachedArea(connection_id_, cached_area_);
 }
 
-// In November 2011 stats were recorded about performance of each of the
-// DOMStorage operations. Results of median, 99% quantile, and 99.9% quantile
-// are provided in milliseconds. The ratio of number of calls for each operation
-// relative to the number of calls to getItem is also provided.
-//
-// Operation    Freq     50%     99%     99.9%
-// -------------------------------------------
-// getItem      1.00     0.6     2.0     27.9
-// setItem      .029     0.7     13.6    114.9
-// removeItem   .003     0.9     11.8    90.7
-// length       .017     0.6     2.0     12.0
-// key          .591     0.6     2.0     29.9
-// clear        1e-6     1.0     32.4    605.2
-
 unsigned WebStorageAreaImpl::length() {
-  unsigned length;
-  RenderThreadImpl::current()->Send(
-      new DOMStorageHostMsg_Length(connection_id_, &length));
-  return length;
+  return cached_area_->GetLength(connection_id_);
 }
 
 WebString WebStorageAreaImpl::key(unsigned index) {
-  NullableString16 key;
-  RenderThreadImpl::current()->Send(
-      new DOMStorageHostMsg_Key(connection_id_, index, &key));
-  return key;
+  return cached_area_->GetKey(connection_id_, index);
 }
 
 WebString WebStorageAreaImpl::getItem(const WebString& key) {
-  NullableString16 value;
-  RenderThreadImpl::current()->Send(
-      new DOMStorageHostMsg_GetItem(connection_id_, key, &value));
-  return value;
+  return cached_area_->GetItem(connection_id_, key);
 }
 
 void WebStorageAreaImpl::setItem(
-    const WebString& key, const WebString& value, const WebURL& url,
-    WebStorageArea::Result& result, WebString& old_value_webkit) {
-  if (key.length() + value.length() > dom_storage::kPerAreaQuota) {
+    const WebString& key, const WebString& value, const WebURL& page_url,
+    WebStorageArea::Result& result) {
+  if (!cached_area_->SetItem(connection_id_, key, value, page_url))
     result = ResultBlockedByQuota;
-    return;
-  }
-  NullableString16 old_value;
-  RenderThreadImpl::current()->Send(new DOMStorageHostMsg_SetItem(
-      connection_id_, key, value, url, &result, &old_value));
-  old_value_webkit = old_value;
+  else
+    result = ResultOK;
 }
 
 void WebStorageAreaImpl::removeItem(
-    const WebString& key, const WebURL& url, WebString& old_value_webkit) {
-  NullableString16 old_value;
-  RenderThreadImpl::current()->Send(
-      new DOMStorageHostMsg_RemoveItem(connection_id_, key, url, &old_value));
-  old_value_webkit = old_value;
+    const WebString& key, const WebURL& page_url) {
+  cached_area_->RemoveItem(connection_id_, key, page_url);
 }
 
-void WebStorageAreaImpl::clear(
-    const WebURL& url, bool& cleared_something) {
-  RenderThreadImpl::current()->Send(
-      new DOMStorageHostMsg_Clear(connection_id_, url, &cleared_something));
+void WebStorageAreaImpl::clear(const WebURL& page_url) {
+  cached_area_->Clear(connection_id_, page_url);
 }