Experimental CompressibleString UMA

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 32 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 {
 
 // Set of all live pages; includes internal Page objects that are
 // not observable from scripts.
 static Page::PageSet& allPages()
 {
     DEFINE_STATIC_LOCAL(Page::PageSet, allPages, ());
     return allPages;
@@ skipping 66 matching lines @@
     , m_openedByDOM(false)
     , m_tabKeyCyclesThroughElements(true)
     , m_defersLoading(false)
     , m_deviceScaleFactor(1)
     , m_visibilityState(PageVisibilityStateVisible)
     , m_isCursorVisible(true)
 #if ENABLE(ASSERT)
     , m_isPainting(false)
 #endif
     , m_frameHost(FrameHost::create(*this))
+    , m_timerForCompressStrings(this, &Page::compressStrings)
 {
     ASSERT(m_editorClient);
 
     ASSERT(!allPages().contains(this));
     allPages().add(this);
 }
 
 Page::~Page()
 {
 #if !ENABLE(OILPAN)
@@ skipping 207 matching lines @@
     for (const Page* page : ordinaryPages()) {
         for (Frame* frame = page->m_mainFrame; frame; frame = frame->tree().traverseNext()) {
             if (frame->isLocalFrame())
                 toLocalFrame(frame)->document()->visitedLinkState().invalidateStyleForLink(linkHash);
         }
     }
 }
 
 void Page::setVisibilityState(PageVisibilityState visibilityState, bool isInitialState)
 {
+    static const double waitingTimeBeforeCompressingString = 10;
+
+    CompressibleStringImpl::setPageBackground(visibilityState == PageVisibilityStateHidden);
     if (m_visibilityState == visibilityState)
         return;
     m_visibilityState = visibilityState;
 
     if (!isInitialState)
         notifyPageVisibilityChanged();
 
     if (!isInitialState && m_mainFrame && m_mainFrame->isLocalFrame())
         deprecatedLocalMainFrame()->didChangeVisibilityState();
+
+    // Compress CompressibleStrings when 10 seconds have passed since the page
+    // went to background.
+    if (m_visibilityState == PageVisibilityStateHidden && !m_timerForCompressStrings.isActive()) {

[haraken, 2016/01/19 07:43:35]

Shouldn't this be:

  if (m_visibilityState == PageVisibilityStateHidden) {
    if (!m_timer.isActive)
      m_timer.startOneShot();
  } else if (m_timer.isActive()) {
    m_timer.stop();
  }

?

[hajimehoshi, 2016/01/19 10:19:20]

Done.

+        m_timerForCompressStrings.startOneShot(waitingTimeBeforeCompressingString, BLINK_FROM_HERE);
+    } else if (m_timerForCompressStrings.isActive()) {
+        m_timerForCompressStrings.stop();
+    }
 }
 
 PageVisibilityState Page::visibilityState() const
 {
     return m_visibilityState;
 }
 
 bool Page::isCursorVisible() const
 {
     return m_isCursorVisible && settings().deviceSupportsMouse();
@@ skipping 192 matching lines @@
         m_scrollingCoordinator->willBeDestroyed();
 
     chromeClient().chromeDestroyed();
     if (m_validationMessageClient)
         m_validationMessageClient->willBeDestroyed();
     m_mainFrame = nullptr;
 
     PageLifecycleNotifier::notifyContextDestroyed();
 }
 
+void Page::compressStrings(Timer<Page>* timer)
+{
+    ASSERT_UNUSED(timer, timer == &m_timerForCompressStrings);
+    if (m_visibilityState == PageVisibilityStateHidden)
+        CompressibleStringImpl::compressAll();
+}
+
 Page::PageClients::PageClients()
     : chromeClient(nullptr)
     , contextMenuClient(nullptr)
     , editorClient(nullptr)
     , dragClient(nullptr)
     , spellCheckerClient(nullptr)
 {
 }
 
 Page::PageClients::~PageClients()
 {
 }
 
 template class CORE_TEMPLATE_EXPORT WillBeHeapSupplement<Page>;
 
 } // namespace blink