[Experimental] CSSSerializer Proof-of-concept

third_party/WebKit/Source/core/css/StyleSheetContents.cpp

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2006, 2007, 2012 Apple Inc. All rights reserved.
  *
  * 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
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #include "core/css/StyleSheetContents.h"
 
 #include "core/css/CSSStyleSheet.h"
 #include "core/css/StylePropertySet.h"
 #include "core/css/StyleRule.h"
 #include "core/css/StyleRuleImport.h"
 #include "core/css/StyleRuleNamespace.h"
 #include "core/css/parser/CSSParser.h"
+#include "core/css/serializer/CSSDeserializeStream.h"
+#include "core/css/serializer/CSSSerializeStream.h"
 #include "core/dom/Document.h"
 #include "core/dom/Node.h"
 #include "core/dom/StyleEngine.h"
 #include "core/fetch/CSSStyleSheetResource.h"
 #include "core/frame/UseCounter.h"
 #include "core/inspector/InspectorTraceEvents.h"
 #include "platform/TraceEvent.h"
 #include "platform/weborigin/SecurityOrigin.h"
 #include "wtf/Deque.h"
 
@@ skipping 77 matching lines @@
 bool StyleSheetContents::isCacheable() const
 {
     // This would require dealing with multiple clients for load callbacks.
     if (!loadCompleted())
         return false;
     // FIXME: StyleSheets with media queries can't be cached because their RuleSet
     // is processed differently based off the media queries, which might resolve
     // differently depending on the context of the parent CSSStyleSheet (e.g.
     // if they are in differently sized iframes). Once RuleSets are media query
     // agnostic, we can restore sharing of StyleSheetContents with medea queries.
-    if (m_hasMediaQueries)
-        return false;
+    CSDEBUG("hasMediaQueries: %d, m_importRules not empty %d, m_ownerRule %d\n",
+        m_hasMediaQueries, !m_importRules.isEmpty(), (bool)m_ownerRule);
+    CSDEBUG("loaderr: %d, mutable: %d, css h invalid: %d\n", m_didLoadErrorOccur, m_isMutable, !m_hasSyntacticallyValidCSSHeader);
+    //if (m_hasMediaQueries)
+    //    return false;
     // FIXME: Support copying import rules.
     if (!m_importRules.isEmpty())
         return false;
     // FIXME: Support cached stylesheets in import rules.
     if (m_ownerRule)
         return false;
     if (m_didLoadErrorOccur)
         return false;
     // It is not the original sheet anymore.
     if (m_isMutable)
         return false;
     // If the header is valid we are not going to need to check the SecurityOrigin.
     // FIXME: Valid mime type avoids the check too.
     if (!m_hasSyntacticallyValidCSSHeader)
         return false;
     return true;
 }
 
+void StyleSheetContents::deserialize(CSSDeserializeStream* stream)
+{
+    CSDEBUG("StyleSheetContents::deserialize\n");
+
+    unsigned numChildRules = stream->readUnsigned();
+    for (unsigned i = 0; i < numChildRules; ++i) {
+        parserAppendRule(StyleRuleBase::deserialize(stream));
+    }
+}
+
+void StyleSheetContents::serialize(CSSSerializeStream* stream)
+{
+    CSDEBUG("StyleSheetContents::serialize isCacheable: %d\n", isCacheable());
+
+    stream->writeUnsigned(m_childRules.size());
+    for (auto childRule : m_childRules) {
+        childRule->serialize(stream);
+    }
+}
+
 void StyleSheetContents::parserAppendRule(PassRefPtrWillBeRawPtr<StyleRuleBase> rule)
 {
     if (rule->isImportRule()) {
         // Parser enforces that @import rules come before anything else
         ASSERT(m_childRules.isEmpty());
         StyleRuleImport* importRule = toStyleRuleImport(rule.get());
         if (importRule->mediaQueries())
             setHasMediaQueries();
         m_importRules.append(importRule);
         m_importRules.last()->setParentStyleSheet(this);
@@ skipping 519 matching lines @@
     visitor->trace(m_importRules);
     visitor->trace(m_namespaceRules);
     visitor->trace(m_childRules);
     visitor->trace(m_loadingClients);
     visitor->trace(m_completedClients);
     visitor->trace(m_ruleSet);
 #endif
 }
 
 }