WIP: Introduce CompressibleString

third_party/WebKit/Source/core/page/Page.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All Rights Reserved.
  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 33 matching lines @@
 #include "core/page/ChromeClient.h"
 #include "core/page/ContextMenuController.h"
 #include "core/page/DragController.h"
 #include "core/page/FocusController.h"
 #include "core/page/PointerLockController.h"
 #include "core/page/ValidationMessageClient.h"
 #include "core/page/scrolling/ScrollingCoordinator.h"
 #include "core/paint/PaintLayer.h"
 #include "platform/graphics/GraphicsLayer.h"
 #include "platform/plugins/PluginData.h"
+#include "platform/text/CompressibleString.h"
 #include "public/platform/Platform.h"
 
 namespace blink {
 
 // static
 WillBePersistentHeapHashSet<RawPtrWillBeWeakMember<Page>>& Page::allPages()
 {
     DEFINE_STATIC_LOCAL(WillBePersistentHeapHashSet<RawPtrWillBeWeakMember<Page>>, allPages, ());
     return allPages;
 }
@@ skipping 469 matching lines @@
             frames.append(toLocalFrame(frame));
     }
 
     for (unsigned i = 0; i < frames.size(); ++i)
         frames[i]->localDOMWindow()->acceptLanguagesChanged();
 }
 
 void Page::purgeMemory(MemoryPurgeMode mode, DeviceKind deviceKind)
 {
     Frame* frame = mainFrame();
-    if (deviceKind != DeviceKind::LowEnd || !frame || !frame->isLocalFrame())
-        return;
-    if (mode == MemoryPurgeMode::InactiveTab) {
-        if (Document* document = toLocalFrame(frame)->document())
-            document->fetcher()->garbageCollectDocumentResources();
-        memoryCache()->pruneAll();
+    if (deviceKind == DeviceKind::LowEnd && frame && frame->isLocalFrame()) {
+        if (mode == MemoryPurgeMode::InactiveTab) {
+            if (Document* document = toLocalFrame(frame)->document())
+                document->fetcher()->garbageCollectDocumentResources();
+            memoryCache()->pruneAll();
+        }
     }
+
+    CompressibleStringImpl::purgeMemory();

[haraken, 2015/11/26 11:50:03]

I'd propose to introduce a separate method for doing the string compression
(e.g., window.compressStrings) to measure the memory impact. If you use
MemoryPurgeController::purgeMemory for the measurement, it will do a bunch of
other reductions at the same time (e.g., memoryCache()->pruneAll()), which will
confuse your measurement.

 }
 
 DEFINE_TRACE(Page)
 {
 #if ENABLE(OILPAN)
     visitor->trace(m_animator);
     visitor->trace(m_autoscrollController);
     visitor->trace(m_chromeClient);
     visitor->trace(m_dragCaretController);
     visitor->trace(m_dragController);
@@ skipping 53 matching lines @@
 {
 }
 
 Page::PageClients::~PageClients()
 {
 }
 
 template class CORE_TEMPLATE_EXPORT WillBeHeapSupplement<Page>;
 
 } // namespace blink