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Diffstat (limited to 'dom/xslt/xpath/txPathExpr.cpp')
| -rw-r--r-- | dom/xslt/xpath/txPathExpr.cpp | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/dom/xslt/xpath/txPathExpr.cpp b/dom/xslt/xpath/txPathExpr.cpp new file mode 100644 index 000000000..bcff47e9f --- /dev/null +++ b/dom/xslt/xpath/txPathExpr.cpp @@ -0,0 +1,253 @@ +/* -*- 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 "txExpr.h" +#include "txNodeSet.h" +#include "txNodeSetContext.h" +#include "txSingleNodeContext.h" +#include "txXMLUtils.h" +#include "txXPathTreeWalker.h" + + //------------/ + //- PathExpr -/ +//------------/ + +/** + * Adds the Expr to this PathExpr + * @param expr the Expr to add to this PathExpr +**/ +nsresult +PathExpr::addExpr(Expr* aExpr, PathOperator aPathOp) +{ + NS_ASSERTION(!mItems.IsEmpty() || aPathOp == RELATIVE_OP, + "First step has to be relative in PathExpr"); + PathExprItem* pxi = mItems.AppendElement(); + if (!pxi) { + return NS_ERROR_OUT_OF_MEMORY; + } + pxi->expr = aExpr; + pxi->pathOp = aPathOp; + + return NS_OK; +} + + //-----------------------------/ + //- 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 ContextState containing the stack information needed + * for evaluation + * @return the result of the evaluation +**/ +nsresult +PathExpr::evaluate(txIEvalContext* aContext, txAExprResult** aResult) +{ + *aResult = nullptr; + + // We need to evaluate the first step with the current context since it + // can depend on the context size and position. For example: + // key('books', concat('book', position())) + RefPtr<txAExprResult> res; + nsresult rv = mItems[0].expr->evaluate(aContext, getter_AddRefs(res)); + NS_ENSURE_SUCCESS(rv, rv); + + NS_ENSURE_TRUE(res->getResultType() == txAExprResult::NODESET, + NS_ERROR_XSLT_NODESET_EXPECTED); + + RefPtr<txNodeSet> nodes = static_cast<txNodeSet*> + (static_cast<txAExprResult*> + (res)); + if (nodes->isEmpty()) { + res.forget(aResult); + + return NS_OK; + } + res = nullptr; // To allow recycling + + // Evaluate remaining steps + uint32_t i, len = mItems.Length(); + for (i = 1; i < len; ++i) { + PathExprItem& pxi = mItems[i]; + RefPtr<txNodeSet> tmpNodes; + txNodeSetContext eContext(nodes, aContext); + while (eContext.hasNext()) { + eContext.next(); + + RefPtr<txNodeSet> resNodes; + if (pxi.pathOp == DESCENDANT_OP) { + rv = aContext->recycler()->getNodeSet(getter_AddRefs(resNodes)); + NS_ENSURE_SUCCESS(rv, rv); + + rv = evalDescendants(pxi.expr, eContext.getContextNode(), + &eContext, resNodes); + NS_ENSURE_SUCCESS(rv, rv); + } + else { + RefPtr<txAExprResult> res; + rv = pxi.expr->evaluate(&eContext, getter_AddRefs(res)); + NS_ENSURE_SUCCESS(rv, rv); + + if (res->getResultType() != txAExprResult::NODESET) { + //XXX ErrorReport: report nonnodeset error + return NS_ERROR_XSLT_NODESET_EXPECTED; + } + resNodes = static_cast<txNodeSet*> + (static_cast<txAExprResult*> + (res)); + } + + if (tmpNodes) { + if (!resNodes->isEmpty()) { + RefPtr<txNodeSet> oldSet; + oldSet.swap(tmpNodes); + rv = aContext->recycler()-> + getNonSharedNodeSet(oldSet, getter_AddRefs(tmpNodes)); + NS_ENSURE_SUCCESS(rv, rv); + + oldSet.swap(resNodes); + rv = aContext->recycler()-> + getNonSharedNodeSet(oldSet, getter_AddRefs(resNodes)); + NS_ENSURE_SUCCESS(rv, rv); + + tmpNodes->addAndTransfer(resNodes); + } + } + else { + tmpNodes = resNodes; + } + } + nodes = tmpNodes; + if (nodes->isEmpty()) { + break; + } + } + + *aResult = nodes; + NS_ADDREF(*aResult); + + return NS_OK; +} //-- evaluate + +/** + * Selects from the descendants of the context node + * all nodes that match the Expr +**/ +nsresult +PathExpr::evalDescendants(Expr* aStep, const txXPathNode& aNode, + txIMatchContext* aContext, txNodeSet* resNodes) +{ + txSingleNodeContext eContext(aNode, aContext); + RefPtr<txAExprResult> res; + nsresult rv = aStep->evaluate(&eContext, getter_AddRefs(res)); + NS_ENSURE_SUCCESS(rv, rv); + + if (res->getResultType() != txAExprResult::NODESET) { + //XXX ErrorReport: report nonnodeset error + return NS_ERROR_XSLT_NODESET_EXPECTED; + } + + txNodeSet* oldSet = static_cast<txNodeSet*> + (static_cast<txAExprResult*>(res)); + RefPtr<txNodeSet> newSet; + rv = aContext->recycler()->getNonSharedNodeSet(oldSet, + getter_AddRefs(newSet)); + NS_ENSURE_SUCCESS(rv, rv); + + resNodes->addAndTransfer(newSet); + + bool filterWS = aContext->isStripSpaceAllowed(aNode); + + txXPathTreeWalker walker(aNode); + if (!walker.moveToFirstChild()) { + return NS_OK; + } + + do { + const txXPathNode& node = walker.getCurrentPosition(); + if (!(filterWS && txXPathNodeUtils::isText(node) && + txXPathNodeUtils::isWhitespace(node))) { + rv = evalDescendants(aStep, node, aContext, resNodes); + NS_ENSURE_SUCCESS(rv, rv); + } + } while (walker.moveToNextSibling()); + + return NS_OK; +} //-- evalDescendants + +Expr::ExprType +PathExpr::getType() +{ + return PATH_EXPR; +} + +TX_IMPL_EXPR_STUBS_BASE(PathExpr, NODESET_RESULT) + +Expr* +PathExpr::getSubExprAt(uint32_t aPos) +{ + return aPos < mItems.Length() ? mItems[aPos].expr.get() : nullptr; +} +void +PathExpr::setSubExprAt(uint32_t aPos, Expr* aExpr) +{ + NS_ASSERTION(aPos < mItems.Length(), "setting bad subexpression index"); + mItems[aPos].expr.forget(); + mItems[aPos].expr = aExpr; +} + + +bool +PathExpr::isSensitiveTo(ContextSensitivity aContext) +{ + if (mItems[0].expr->isSensitiveTo(aContext)) { + return true; + } + + // We're creating a new node/nodeset so we can ignore those bits. + Expr::ContextSensitivity context = + aContext & ~(Expr::NODE_CONTEXT | Expr::NODESET_CONTEXT); + if (context == NO_CONTEXT) { + return false; + } + + uint32_t i, len = mItems.Length(); + for (i = 0; i < len; ++i) { + NS_ASSERTION(!mItems[i].expr->isSensitiveTo(Expr::NODESET_CONTEXT), + "Step cannot depend on nodeset-context"); + if (mItems[i].expr->isSensitiveTo(context)) { + return true; + } + } + + return false; +} + +#ifdef TX_TO_STRING +void +PathExpr::toString(nsAString& dest) +{ + if (!mItems.IsEmpty()) { + NS_ASSERTION(mItems[0].pathOp == RELATIVE_OP, + "First step should be relative"); + mItems[0].expr->toString(dest); + } + + uint32_t i, len = mItems.Length(); + for (i = 1; i < len; ++i) { + switch (mItems[i].pathOp) { + case DESCENDANT_OP: + dest.AppendLiteral("//"); + break; + case RELATIVE_OP: + dest.Append(char16_t('/')); + break; + } + mItems[i].expr->toString(dest); + } +} +#endif |