The Tor Browser: dom/xslt/xpath/txPredicateList.cpp@97036ab72558

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.

     1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

     2 /* This Source Code Form is subject to the terms of the Mozilla Public

     3  * License, v. 2.0. If a copy of the MPL was not distributed with this

     4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     6 #include "txExpr.h"

     7 #include "txNodeSet.h"

     8 #include "txNodeSetContext.h"

    10 /*

    11  * Represents an ordered list of Predicates,

    12  * for use with Step and Filter Expressions

    13  */

    15 nsresult

    16 PredicateList::evaluatePredicates(txNodeSet* nodes,

    17                                   txIMatchContext* aContext)

    18 {

    19     NS_ASSERTION(nodes, "called evaluatePredicates with nullptr NodeSet");

    20     nsresult rv = NS_OK;

    22     uint32_t i, len = mPredicates.Length();

    23     for (i = 0; i < len && !nodes->isEmpty(); ++i) {

    24         txNodeSetContext predContext(nodes, aContext);

    25         /*

    26          * add nodes to newNodes that match the expression

    27          * or, if the result is a number, add the node with the right

    28          * position

    29          */

    30         int32_t index = 0;

    31         while (predContext.hasNext()) {

    32             predContext.next();

    33             nsRefPtr<txAExprResult> exprResult;

    34             rv = mPredicates[i]->evaluate(&predContext,

    35                                           getter_AddRefs(exprResult));

    36             NS_ENSURE_SUCCESS(rv, rv);

    38             // handle default, [position() == numberValue()]

    39             if (exprResult->getResultType() == txAExprResult::NUMBER) {

    40                 if ((double)predContext.position() == exprResult->numberValue()) {

    41                     nodes->mark(index);

    42                 }

    43             }

    44             else if (exprResult->booleanValue()) {

    45                 nodes->mark(index);

    46             }

    47             ++index;

    48         }

    49         // sweep the non-marked nodes

    50         nodes->sweep();

    51     }

    53     return NS_OK;

    54 }

    56 bool

    57 PredicateList::isSensitiveTo(Expr::ContextSensitivity aContext)

    58 {

    59     // We're creating a new node/nodeset so we can ignore those bits.

    60     Expr::ContextSensitivity context =

    61         aContext & ~(Expr::NODE_CONTEXT | Expr::NODESET_CONTEXT);

    62     if (context == Expr::NO_CONTEXT) {

    63         return false;

    64     }

    66     uint32_t i, len = mPredicates.Length();

    67     for (i = 0; i < len; ++i) {

    68         if (mPredicates[i]->isSensitiveTo(context)) {

    69             return true;

    70         }

    71     }

    73     return false;

    74 }

    76 #ifdef TX_TO_STRING

    77 void PredicateList::toString(nsAString& dest)

    78 {

    79     for (uint32_t i = 0; i < mPredicates.Length(); ++i) {

    80         dest.Append(char16_t('['));

    81         mPredicates[i]->toString(dest);

    82         dest.Append(char16_t(']'));

    83     }

    84 }

    85 #endif

The Tor Browser / file revision

dom/xslt/xpath/txPredicateList.cpp@97036ab72558

dom/xslt/xpath/txPredicateList.cpp