/* -*- 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/. */ /* Implementation of an XPath LocationStep */ #include "txExpr.h" #include "txIXPathContext.h" #include "txNodeSet.h" #include "txXPathTreeWalker.h" //-----------------------------/ //- Virtual methods from Expr -/ //-----------------------------/ /** * Evaluates this Expr based on the given context node and processor state * @param context the context node for evaluation of this Expr * @param ps the ProcessorState containing the stack information needed * for evaluation * @return the result of the evaluation * @see Expr **/ nsresult LocationStep::evaluate(txIEvalContext* aContext, txAExprResult** aResult) { NS_ASSERTION(aContext, "internal error"); *aResult = nullptr; RefPtr nodes; nsresult rv = aContext->recycler()->getNodeSet(getter_AddRefs(nodes)); NS_ENSURE_SUCCESS(rv, rv); txXPathTreeWalker walker(aContext->getContextNode()); switch (mAxisIdentifier) { case ANCESTOR_AXIS: { if (!walker.moveToParent()) { break; } MOZ_FALLTHROUGH; } case ANCESTOR_OR_SELF_AXIS: { nodes->setReverse(); do { if (mNodeTest->matches(walker.getCurrentPosition(), aContext)) { nodes->append(walker.getCurrentPosition()); } } while (walker.moveToParent()); break; } case ATTRIBUTE_AXIS: { if (!walker.moveToFirstAttribute()) { break; } do { if (mNodeTest->matches(walker.getCurrentPosition(), aContext)) { nodes->append(walker.getCurrentPosition()); } } while (walker.moveToNextAttribute()); break; } case DESCENDANT_OR_SELF_AXIS: { if (mNodeTest->matches(walker.getCurrentPosition(), aContext)) { nodes->append(walker.getCurrentPosition()); } MOZ_FALLTHROUGH; } case DESCENDANT_AXIS: { fromDescendants(walker.getCurrentPosition(), aContext, nodes); break; } case FOLLOWING_AXIS: { if (txXPathNodeUtils::isAttribute(walker.getCurrentPosition())) { walker.moveToParent(); fromDescendants(walker.getCurrentPosition(), aContext, nodes); } bool cont = true; while (!walker.moveToNextSibling()) { if (!walker.moveToParent()) { cont = false; break; } } while (cont) { if (mNodeTest->matches(walker.getCurrentPosition(), aContext)) { nodes->append(walker.getCurrentPosition()); } fromDescendants(walker.getCurrentPosition(), aContext, nodes); while (!walker.moveToNextSibling()) { if (!walker.moveToParent()) { cont = false; break; } } } break; } case FOLLOWING_SIBLING_AXIS: { while (walker.moveToNextSibling()) { if (mNodeTest->matches(walker.getCurrentPosition(), aContext)) { nodes->append(walker.getCurrentPosition()); } } break; } case NAMESPACE_AXIS: //-- not yet implemented #if 0 // XXX DEBUG OUTPUT cout << "namespace axis not yet implemented"<matches(walker.getCurrentPosition(), aContext)) { nodes->append(walker.getCurrentPosition()); } break; } case PRECEDING_AXIS: { nodes->setReverse(); bool cont = true; while (!walker.moveToPreviousSibling()) { if (!walker.moveToParent()) { cont = false; break; } } while (cont) { fromDescendantsRev(walker.getCurrentPosition(), aContext, nodes); if (mNodeTest->matches(walker.getCurrentPosition(), aContext)) { nodes->append(walker.getCurrentPosition()); } while (!walker.moveToPreviousSibling()) { if (!walker.moveToParent()) { cont = false; break; } } } break; } case PRECEDING_SIBLING_AXIS: { nodes->setReverse(); while (walker.moveToPreviousSibling()) { if (mNodeTest->matches(walker.getCurrentPosition(), aContext)) { nodes->append(walker.getCurrentPosition()); } } break; } case SELF_AXIS: { if (mNodeTest->matches(walker.getCurrentPosition(), aContext)) { nodes->append(walker.getCurrentPosition()); } break; } default: // Children Axis { if (!walker.moveToFirstChild()) { break; } do { if (mNodeTest->matches(walker.getCurrentPosition(), aContext)) { nodes->append(walker.getCurrentPosition()); } } while (walker.moveToNextSibling()); break; } } // Apply predicates if (!isEmpty()) { rv = evaluatePredicates(nodes, aContext); NS_ENSURE_SUCCESS(rv, rv); } nodes->unsetReverse(); NS_ADDREF(*aResult = nodes); return NS_OK; } void LocationStep::fromDescendants(const txXPathNode& aNode, txIMatchContext* aCs, txNodeSet* aNodes) { txXPathTreeWalker walker(aNode); if (!walker.moveToFirstChild()) { return; } do { const txXPathNode& child = walker.getCurrentPosition(); if (mNodeTest->matches(child, aCs)) { aNodes->append(child); } fromDescendants(child, aCs, aNodes); } while (walker.moveToNextSibling()); } void LocationStep::fromDescendantsRev(const txXPathNode& aNode, txIMatchContext* aCs, txNodeSet* aNodes) { txXPathTreeWalker walker(aNode); if (!walker.moveToLastChild()) { return; } do { const txXPathNode& child = walker.getCurrentPosition(); fromDescendantsRev(child, aCs, aNodes); if (mNodeTest->matches(child, aCs)) { aNodes->append(child); } } while (walker.moveToPreviousSibling()); } Expr::ExprType LocationStep::getType() { return LOCATIONSTEP_EXPR; } TX_IMPL_EXPR_STUBS_BASE(LocationStep, NODESET_RESULT) Expr* LocationStep::getSubExprAt(uint32_t aPos) { return PredicateList::getSubExprAt(aPos); } void LocationStep::setSubExprAt(uint32_t aPos, Expr* aExpr) { PredicateList::setSubExprAt(aPos, aExpr); } bool LocationStep::isSensitiveTo(ContextSensitivity aContext) { return (aContext & NODE_CONTEXT) || mNodeTest->isSensitiveTo(aContext) || PredicateList::isSensitiveTo(aContext); } #ifdef TX_TO_STRING void LocationStep::toString(nsAString& str) { switch (mAxisIdentifier) { case ANCESTOR_AXIS : str.AppendLiteral("ancestor::"); break; case ANCESTOR_OR_SELF_AXIS : str.AppendLiteral("ancestor-or-self::"); break; case ATTRIBUTE_AXIS: str.Append(char16_t('@')); break; case DESCENDANT_AXIS: str.AppendLiteral("descendant::"); break; case DESCENDANT_OR_SELF_AXIS: str.AppendLiteral("descendant-or-self::"); break; case FOLLOWING_AXIS : str.AppendLiteral("following::"); break; case FOLLOWING_SIBLING_AXIS: str.AppendLiteral("following-sibling::"); break; case NAMESPACE_AXIS: str.AppendLiteral("namespace::"); break; case PARENT_AXIS : str.AppendLiteral("parent::"); break; case PRECEDING_AXIS : str.AppendLiteral("preceding::"); break; case PRECEDING_SIBLING_AXIS : str.AppendLiteral("preceding-sibling::"); break; case SELF_AXIS : str.AppendLiteral("self::"); break; default: break; } NS_ASSERTION(mNodeTest, "mNodeTest is null, that's verboten"); mNodeTest->toString(str); PredicateList::toString(str); } #endif