The Tor Browser: dom/xslt/xpath/txResultRecycler.cpp@97036ab72558 (annotated)

dom/xslt/xpath/txResultRecycler.cpp@97036ab72558 (annotated)

dom/xslt/xpath/txResultRecycler.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: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 /* 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/. */
 #include "txResultRecycler.h"
 #include "txExprResult.h"
 #include "txNodeSet.h"
 txResultRecycler::txResultRecycler()
     : mEmptyStringResult(nullptr),
       mTrueResult(nullptr),
       mFalseResult(nullptr)
 {
 }
 txResultRecycler::~txResultRecycler()
 {
     txStackIterator stringIter(&mStringResults);
     while (stringIter.hasNext()) {
         delete static_cast<StringResult*>(stringIter.next());
     }
     txStackIterator nodesetIter(&mNodeSetResults);
     while (nodesetIter.hasNext()) {
         delete static_cast<txNodeSet*>(nodesetIter.next());
     }
     txStackIterator numberIter(&mNumberResults);
     while (numberIter.hasNext()) {
         delete static_cast<NumberResult*>(numberIter.next());
     }
     NS_IF_RELEASE(mEmptyStringResult);
     NS_IF_RELEASE(mTrueResult);
     NS_IF_RELEASE(mFalseResult);
 }
 nsresult
 txResultRecycler::init()
 {
     NS_ASSERTION(!mEmptyStringResult && !mTrueResult && !mFalseResult,
                  "Already inited");
     mEmptyStringResult = new StringResult(nullptr);
     NS_ENSURE_TRUE(mEmptyStringResult, NS_ERROR_OUT_OF_MEMORY);
     NS_ADDREF(mEmptyStringResult);
     mTrueResult = new BooleanResult(true);
     NS_ENSURE_TRUE(mTrueResult, NS_ERROR_OUT_OF_MEMORY);
     NS_ADDREF(mTrueResult);
     mFalseResult = new BooleanResult(false);
     NS_ENSURE_TRUE(mFalseResult, NS_ERROR_OUT_OF_MEMORY);
     NS_ADDREF(mFalseResult);
     return NS_OK;
 }
 void
 txResultRecycler::recycle(txAExprResult* aResult)
 {
     NS_ASSERTION(aResult->mRefCnt == 0, "In-use txAExprResult recycled");
     nsRefPtr<txResultRecycler> kungFuDeathGrip;
     aResult->mRecycler.swap(kungFuDeathGrip);
     nsresult rv = NS_OK;
     switch (aResult->getResultType()) {
         case txAExprResult::STRING:
         {
             rv = mStringResults.push(static_cast<StringResult*>(aResult));
             if (NS_FAILED(rv)) {
                 delete aResult;
             }
             return;
         }
         case txAExprResult::NODESET:
         {
             static_cast<txNodeSet*>(aResult)->clear();
             rv = mNodeSetResults.push(static_cast<txNodeSet*>(aResult));
             if (NS_FAILED(rv)) {
                 delete aResult;
             }
             return;
         }
         case txAExprResult::NUMBER:
         {
             rv = mNumberResults.push(static_cast<NumberResult*>(aResult));
             if (NS_FAILED(rv)) {
                 delete aResult;
             }
             return;
         }
         default:
         {
             delete aResult;
         }
     }
 }
 nsresult
 txResultRecycler::getStringResult(StringResult** aResult)
 {
     if (mStringResults.isEmpty()) {
         *aResult = new StringResult(this);
         NS_ENSURE_TRUE(*aResult, NS_ERROR_OUT_OF_MEMORY);
     }
     else {
         *aResult = static_cast<StringResult*>(mStringResults.pop());
         (*aResult)->mValue.Truncate();
         (*aResult)->mRecycler = this;
     }
     NS_ADDREF(*aResult);
     return NS_OK;
 }
 nsresult
 txResultRecycler::getStringResult(const nsAString& aValue,
                                   txAExprResult** aResult)
 {
     if (mStringResults.isEmpty()) {
         *aResult = new StringResult(aValue, this);
         NS_ENSURE_TRUE(*aResult, NS_ERROR_OUT_OF_MEMORY);
     }
     else {
         StringResult* strRes =
             static_cast<StringResult*>(mStringResults.pop());
         strRes->mValue = aValue;
         strRes->mRecycler = this;
         *aResult = strRes;
     }
     NS_ADDREF(*aResult);
     return NS_OK;
 }
 void
 txResultRecycler::getEmptyStringResult(txAExprResult** aResult)
 {
     *aResult = mEmptyStringResult;
     NS_ADDREF(*aResult);
 }
 nsresult
 txResultRecycler::getNodeSet(txNodeSet** aResult)
 {
     if (mNodeSetResults.isEmpty()) {
         *aResult = new txNodeSet(this);
         NS_ENSURE_TRUE(*aResult, NS_ERROR_OUT_OF_MEMORY);
     }
     else {
         *aResult = static_cast<txNodeSet*>(mNodeSetResults.pop());
         (*aResult)->mRecycler = this;
     }
     NS_ADDREF(*aResult);
     return NS_OK;
 }
 nsresult
 txResultRecycler::getNodeSet(txNodeSet* aNodeSet, txNodeSet** aResult)
 {
     if (mNodeSetResults.isEmpty()) {
         *aResult = new txNodeSet(*aNodeSet, this);
         NS_ENSURE_TRUE(*aResult, NS_ERROR_OUT_OF_MEMORY);
     }
     else {
         *aResult = static_cast<txNodeSet*>(mNodeSetResults.pop());
         (*aResult)->append(*aNodeSet);
         (*aResult)->mRecycler = this;
     }
     NS_ADDREF(*aResult);
     return NS_OK;
 }
 nsresult
 txResultRecycler::getNodeSet(const txXPathNode& aNode, txAExprResult** aResult)
 {
     if (mNodeSetResults.isEmpty()) {
         *aResult = new txNodeSet(aNode, this);
         NS_ENSURE_TRUE(*aResult, NS_ERROR_OUT_OF_MEMORY);
     }
     else {
         txNodeSet* nodes = static_cast<txNodeSet*>(mNodeSetResults.pop());
         nodes->append(aNode);
         nodes->mRecycler = this;
         *aResult = nodes;
     }
     NS_ADDREF(*aResult);
     return NS_OK;
 }
 nsresult
 txResultRecycler::getNumberResult(double aValue, txAExprResult** aResult)
 {
     if (mNumberResults.isEmpty()) {
         *aResult = new NumberResult(aValue, this);
         NS_ENSURE_TRUE(*aResult, NS_ERROR_OUT_OF_MEMORY);
     }
     else {
         NumberResult* numRes =
             static_cast<NumberResult*>(mNumberResults.pop());
         numRes->value = aValue;
         numRes->mRecycler = this;
         *aResult = numRes;
     }
     NS_ADDREF(*aResult);
     return NS_OK;
 }
 void
 txResultRecycler::getBoolResult(bool aValue, txAExprResult** aResult)
 {
     *aResult = aValue ? mTrueResult : mFalseResult;
     NS_ADDREF(*aResult);
 }
 nsresult
 txResultRecycler::getNonSharedNodeSet(txNodeSet* aNodeSet, txNodeSet** aResult)
 {
     if (aNodeSet->mRefCnt > 1) {
         return getNodeSet(aNodeSet, aResult);
     }
     *aResult = aNodeSet;
     NS_ADDREF(*aResult);
     return NS_OK;
 }
 void
 txAExprResult::Release()
 {
     --mRefCnt;
     NS_LOG_RELEASE(this, mRefCnt, "txAExprResult");
     if (mRefCnt == 0) {
         if (mRecycler) {
             mRecycler->recycle(this);
         }
         else {
             delete this;
         }
     }
 }

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dom/xslt/xpath/txResultRecycler.cpp@97036ab72558 (annotated)

dom/xslt/xpath/txResultRecycler.cpp