The Tor Browser: layout/style/nsHTMLCSSStyleSheet.cpp@97036ab72558 (annotated)

layout/style/nsHTMLCSSStyleSheet.cpp@97036ab72558 (annotated)

layout/style/nsHTMLCSSStyleSheet.cpp

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 /*
  * style sheet and style rule processor representing style attributes
  */
 #include "nsHTMLCSSStyleSheet.h"
 #include "mozilla/MemoryReporting.h"
 #include "mozilla/css/StyleRule.h"
 #include "nsIStyleRuleProcessor.h"
 #include "nsPresContext.h"
 #include "nsRuleWalker.h"
 #include "nsRuleProcessorData.h"
 #include "mozilla/dom/Element.h"
 #include "nsAttrValue.h"
 #include "nsAttrValueInlines.h"
 using namespace mozilla;
 using namespace mozilla::dom;
 namespace {
 PLDHashOperator
 ClearAttrCache(const nsAString& aKey, MiscContainer*& aValue, void*)
 {
   // Ideally we'd just call MiscContainer::Evict, but we can't do that since
   // we're iterating the hashtable.
   MOZ_ASSERT(aValue->mType == nsAttrValue::eCSSStyleRule);
   aValue->mValue.mCSSStyleRule->SetHTMLCSSStyleSheet(nullptr);
   aValue->mValue.mCached = 0;
   return PL_DHASH_REMOVE;
 }
 } // anonymous namespace
 nsHTMLCSSStyleSheet::nsHTMLCSSStyleSheet()
 {
 }
 nsHTMLCSSStyleSheet::~nsHTMLCSSStyleSheet()
 {
   // We may go away before all of our cached style attributes do,
   // so clean up any that are left.
   mCachedStyleAttrs.Enumerate(ClearAttrCache, nullptr);
 }
 NS_IMPL_ISUPPORTS(nsHTMLCSSStyleSheet, nsIStyleRuleProcessor)
 /* virtual */ void
 nsHTMLCSSStyleSheet::RulesMatching(ElementRuleProcessorData* aData)
 {
   Element* element = aData->mElement;
   // just get the one and only style rule from the content's STYLE attribute
   css::StyleRule* rule = element->GetInlineStyleRule();
   if (rule) {
     rule->RuleMatched();
     aData->mRuleWalker->Forward(rule);
   }
   rule = element->GetSMILOverrideStyleRule();
   if (rule) {
     if (aData->mPresContext->IsProcessingRestyles() &&
         !aData->mPresContext->IsProcessingAnimationStyleChange()) {
       // Non-animation restyle -- don't process SMIL override style, because we
       // don't want SMIL animation to trigger new CSS transitions. Instead,
       // request an Animation restyle, so we still get noticed.
       aData->mPresContext->PresShell()->RestyleForAnimation(element,
                                                             eRestyle_Self);
     } else {
       // Animation restyle (or non-restyle traversal of rules)
       // Now we can walk SMIL overrride style, without triggering transitions.
       rule->RuleMatched();
       aData->mRuleWalker->Forward(rule);
     }
   }
 }
 /* virtual */ void
 nsHTMLCSSStyleSheet::RulesMatching(PseudoElementRuleProcessorData* aData)
 {
   if (nsCSSPseudoElements::PseudoElementSupportsStyleAttribute(aData->mPseudoType)) {
     MOZ_ASSERT(aData->mPseudoElement,
         "If pseudo element is supposed to support style attribute, it must "
         "have a pseudo element set");
     // just get the one and only style rule from the content's STYLE attribute
     css::StyleRule* rule = aData->mPseudoElement->GetInlineStyleRule();
     if (rule) {
       rule->RuleMatched();
       aData->mRuleWalker->Forward(rule);
     }
   }
 }
 /* virtual */ void
 nsHTMLCSSStyleSheet::RulesMatching(AnonBoxRuleProcessorData* aData)
 {
 }
 #ifdef MOZ_XUL
 /* virtual */ void
 nsHTMLCSSStyleSheet::RulesMatching(XULTreeRuleProcessorData* aData)
 {
 }
 #endif
 // Test if style is dependent on content state
 /* virtual */ nsRestyleHint
 nsHTMLCSSStyleSheet::HasStateDependentStyle(StateRuleProcessorData* aData)
 {
   return nsRestyleHint(0);
 }
 /* virtual */ nsRestyleHint
 nsHTMLCSSStyleSheet::HasStateDependentStyle(PseudoElementStateRuleProcessorData* aData)
 {
   return nsRestyleHint(0);
 }
 /* virtual */ bool
 nsHTMLCSSStyleSheet::HasDocumentStateDependentStyle(StateRuleProcessorData* aData)
 {
   return false;
 }
 // Test if style is dependent on attribute
 /* virtual */ nsRestyleHint
 nsHTMLCSSStyleSheet::HasAttributeDependentStyle(AttributeRuleProcessorData* aData)
 {
   // Perhaps should check that it's XUL, SVG, (or HTML) namespace, but
   // it doesn't really matter.
   if (aData->mAttrHasChanged && aData->mAttribute == nsGkAtoms::style) {
     return eRestyle_Self;
   }
   return nsRestyleHint(0);
 }
 /* virtual */ bool
 nsHTMLCSSStyleSheet::MediumFeaturesChanged(nsPresContext* aPresContext)
 {
   return false;
 }
 /* virtual */ size_t
 nsHTMLCSSStyleSheet::SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
 {
   return 0;
 }
 /* virtual */ size_t
 nsHTMLCSSStyleSheet::SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
 {
   return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
 }
 void
 nsHTMLCSSStyleSheet::CacheStyleAttr(const nsAString& aSerialized,
                                     MiscContainer* aValue)
 {
   mCachedStyleAttrs.Put(aSerialized, aValue);
 }
 void
 nsHTMLCSSStyleSheet::EvictStyleAttr(const nsAString& aSerialized,
                                     MiscContainer* aValue)
 {
 #ifdef DEBUG
   {
     NS_ASSERTION(aValue = mCachedStyleAttrs.Get(aSerialized),
                  "Cached value does not match?!");
   }
 #endif
   mCachedStyleAttrs.Remove(aSerialized);
 }
 MiscContainer*
 nsHTMLCSSStyleSheet::LookupStyleAttr(const nsAString& aSerialized)
 {
   return mCachedStyleAttrs.Get(aSerialized);
 }

The Tor Browser / annotate

layout/style/nsHTMLCSSStyleSheet.cpp@97036ab72558 (annotated)

layout/style/nsHTMLCSSStyleSheet.cpp