tor-browser

The Tor Browser
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txFilterExpr.cpp (2470B)

      1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      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/. */
      5 
      6 #include "txExpr.h"
      7 #include "txIXPathContext.h"
      8 #include "txNodeSet.h"
      9 
     10 using mozilla::WrapUnique;
     11 
     12 //-- Implementation of FilterExpr --/
     13 
     14 //-----------------------------/
     15 //- Virtual methods from Expr -/
     16 //-----------------------------/
     17 
     18 /**
     19 * Evaluates this Expr based on the given context node and processor state
     20 * @param context the context node for evaluation of this Expr
     21 * @param ps the ProcessorState containing the stack information needed
     22 * for evaluation
     23 * @return the result of the evaluation
     24 * @see Expr
     25 **/
     26 nsresult FilterExpr::evaluate(txIEvalContext* aContext,
     27                              txAExprResult** aResult) {
     28  *aResult = nullptr;
     29 
     30  RefPtr<txAExprResult> exprRes;
     31  nsresult rv = expr->evaluate(aContext, getter_AddRefs(exprRes));
     32  NS_ENSURE_SUCCESS(rv, rv);
     33 
     34  NS_ENSURE_TRUE(exprRes->getResultType() == txAExprResult::NODESET,
     35                 NS_ERROR_XSLT_NODESET_EXPECTED);
     36 
     37  RefPtr<txNodeSet> nodes =
     38      static_cast<txNodeSet*>(static_cast<txAExprResult*>(exprRes));
     39  // null out exprRes so that we can test for shared-ness
     40  exprRes = nullptr;
     41 
     42  RefPtr<txNodeSet> nonShared;
     43  rv = aContext->recycler()->getNonSharedNodeSet(nodes,
     44                                                 getter_AddRefs(nonShared));
     45  NS_ENSURE_SUCCESS(rv, rv);
     46 
     47  rv = evaluatePredicates(nonShared, aContext);
     48  NS_ENSURE_SUCCESS(rv, rv);
     49 
     50  *aResult = nonShared;
     51  NS_ADDREF(*aResult);
     52 
     53  return NS_OK;
     54 }  //-- evaluate
     55 
     56 TX_IMPL_EXPR_STUBS_BASE(FilterExpr, NODESET_RESULT)
     57 
     58 Expr* FilterExpr::getSubExprAt(uint32_t aPos) {
     59  if (aPos == 0) {
     60    return expr.get();
     61  }
     62  return PredicateList::getSubExprAt(aPos - 1);
     63 }
     64 
     65 void FilterExpr::setSubExprAt(uint32_t aPos, Expr* aExpr) {
     66  if (aPos == 0) {
     67    (void)expr.release();
     68    expr = WrapUnique(aExpr);
     69  } else {
     70    PredicateList::setSubExprAt(aPos - 1, aExpr);
     71  }
     72 }
     73 
     74 bool FilterExpr::isSensitiveTo(ContextSensitivity aContext) {
     75  return expr->isSensitiveTo(aContext) ||
     76         PredicateList::isSensitiveTo(aContext);
     77 }
     78 
     79 #ifdef TX_TO_STRING
     80 void FilterExpr::toString(nsAString& str) {
     81  if (expr)
     82    expr->toString(str);
     83  else
     84    str.AppendLiteral("null");
     85  PredicateList::toString(str);
     86 }
     87 #endif