michael@0: /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "txExpr.h"
michael@0: #include "txNodeSet.h"
michael@0: #include "txNodeSetContext.h"
michael@0: #include "txSingleNodeContext.h"
michael@0: #include "txXMLUtils.h"
michael@0: #include "txXPathTreeWalker.h"
michael@0: 
michael@0:   //------------/
michael@0:  //- PathExpr -/
michael@0: //------------/
michael@0: 
michael@0: /**
michael@0:  * Adds the Expr to this PathExpr
michael@0:  * @param expr the Expr to add to this PathExpr
michael@0: **/
michael@0: nsresult
michael@0: PathExpr::addExpr(Expr* aExpr, PathOperator aPathOp)
michael@0: {
michael@0:     NS_ASSERTION(!mItems.IsEmpty() || aPathOp == RELATIVE_OP,
michael@0:                  "First step has to be relative in PathExpr");
michael@0:     PathExprItem* pxi = mItems.AppendElement();
michael@0:     if (!pxi) {
michael@0:         return NS_ERROR_OUT_OF_MEMORY;
michael@0:     }
michael@0:     pxi->expr = aExpr;
michael@0:     pxi->pathOp = aPathOp;
michael@0: 
michael@0:     return NS_OK;
michael@0: }
michael@0: 
michael@0:     //-----------------------------/
michael@0:   //- Virtual methods from Expr -/
michael@0: //-----------------------------/
michael@0: 
michael@0: /**
michael@0:  * Evaluates this Expr based on the given context node and processor state
michael@0:  * @param context the context node for evaluation of this Expr
michael@0:  * @param ps the ContextState containing the stack information needed
michael@0:  * for evaluation
michael@0:  * @return the result of the evaluation
michael@0: **/
michael@0: nsresult
michael@0: PathExpr::evaluate(txIEvalContext* aContext, txAExprResult** aResult)
michael@0: {
michael@0:     *aResult = nullptr;
michael@0: 
michael@0:     // We need to evaluate the first step with the current context since it
michael@0:     // can depend on the context size and position. For example:
michael@0:     // key('books', concat('book', position()))
michael@0:     nsRefPtr<txAExprResult> res;
michael@0:     nsresult rv = mItems[0].expr->evaluate(aContext, getter_AddRefs(res));
michael@0:     NS_ENSURE_SUCCESS(rv, rv);
michael@0: 
michael@0:     NS_ENSURE_TRUE(res->getResultType() == txAExprResult::NODESET,
michael@0:                    NS_ERROR_XSLT_NODESET_EXPECTED);
michael@0: 
michael@0:     nsRefPtr<txNodeSet> nodes = static_cast<txNodeSet*>
michael@0:                                            (static_cast<txAExprResult*>
michael@0:                                                        (res));
michael@0:     if (nodes->isEmpty()) {
michael@0:         res.swap(*aResult);
michael@0: 
michael@0:         return NS_OK;
michael@0:     }
michael@0:     res = nullptr; // To allow recycling
michael@0: 
michael@0:     // Evaluate remaining steps
michael@0:     uint32_t i, len = mItems.Length();
michael@0:     for (i = 1; i < len; ++i) {
michael@0:         PathExprItem& pxi = mItems[i];
michael@0:         nsRefPtr<txNodeSet> tmpNodes;
michael@0:         txNodeSetContext eContext(nodes, aContext);
michael@0:         while (eContext.hasNext()) {
michael@0:             eContext.next();
michael@0: 
michael@0:             nsRefPtr<txNodeSet> resNodes;
michael@0:             if (pxi.pathOp == DESCENDANT_OP) {
michael@0:                 rv = aContext->recycler()->getNodeSet(getter_AddRefs(resNodes));
michael@0:                 NS_ENSURE_SUCCESS(rv, rv);
michael@0: 
michael@0:                 rv = evalDescendants(pxi.expr, eContext.getContextNode(),
michael@0:                                      &eContext, resNodes);
michael@0:                 NS_ENSURE_SUCCESS(rv, rv);
michael@0:             }
michael@0:             else {
michael@0:                 nsRefPtr<txAExprResult> res;
michael@0:                 rv = pxi.expr->evaluate(&eContext, getter_AddRefs(res));
michael@0:                 NS_ENSURE_SUCCESS(rv, rv);
michael@0: 
michael@0:                 if (res->getResultType() != txAExprResult::NODESET) {
michael@0:                     //XXX ErrorReport: report nonnodeset error
michael@0:                     return NS_ERROR_XSLT_NODESET_EXPECTED;
michael@0:                 }
michael@0:                 resNodes = static_cast<txNodeSet*>
michael@0:                                       (static_cast<txAExprResult*>
michael@0:                                                   (res));
michael@0:             }
michael@0: 
michael@0:             if (tmpNodes) {
michael@0:                 if (!resNodes->isEmpty()) {
michael@0:                     nsRefPtr<txNodeSet> oldSet;
michael@0:                     oldSet.swap(tmpNodes);
michael@0:                     rv = aContext->recycler()->
michael@0:                         getNonSharedNodeSet(oldSet, getter_AddRefs(tmpNodes));
michael@0:                     NS_ENSURE_SUCCESS(rv, rv);
michael@0: 
michael@0:                     oldSet.swap(resNodes);
michael@0:                     rv = aContext->recycler()->
michael@0:                         getNonSharedNodeSet(oldSet, getter_AddRefs(resNodes));
michael@0:                     NS_ENSURE_SUCCESS(rv, rv);
michael@0: 
michael@0:                     tmpNodes->addAndTransfer(resNodes);
michael@0:                 }
michael@0:             }
michael@0:             else {
michael@0:                 tmpNodes = resNodes;
michael@0:             }
michael@0:         }
michael@0:         nodes = tmpNodes;
michael@0:         if (nodes->isEmpty()) {
michael@0:             break;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     *aResult = nodes;
michael@0:     NS_ADDREF(*aResult);
michael@0:     
michael@0:     return NS_OK;
michael@0: } //-- evaluate
michael@0: 
michael@0: /**
michael@0:  * Selects from the descendants of the context node
michael@0:  * all nodes that match the Expr
michael@0: **/
michael@0: nsresult
michael@0: PathExpr::evalDescendants(Expr* aStep, const txXPathNode& aNode,
michael@0:                           txIMatchContext* aContext, txNodeSet* resNodes)
michael@0: {
michael@0:     txSingleNodeContext eContext(aNode, aContext);
michael@0:     nsRefPtr<txAExprResult> res;
michael@0:     nsresult rv = aStep->evaluate(&eContext, getter_AddRefs(res));
michael@0:     NS_ENSURE_SUCCESS(rv, rv);
michael@0: 
michael@0:     if (res->getResultType() != txAExprResult::NODESET) {
michael@0:         //XXX ErrorReport: report nonnodeset error
michael@0:         return NS_ERROR_XSLT_NODESET_EXPECTED;
michael@0:     }
michael@0: 
michael@0:     txNodeSet* oldSet = static_cast<txNodeSet*>
michael@0:                                    (static_cast<txAExprResult*>(res));
michael@0:     nsRefPtr<txNodeSet> newSet;
michael@0:     rv = aContext->recycler()->getNonSharedNodeSet(oldSet,
michael@0:                                                    getter_AddRefs(newSet));
michael@0:     NS_ENSURE_SUCCESS(rv, rv);
michael@0: 
michael@0:     resNodes->addAndTransfer(newSet);
michael@0: 
michael@0:     bool filterWS = aContext->isStripSpaceAllowed(aNode);
michael@0: 
michael@0:     txXPathTreeWalker walker(aNode);
michael@0:     if (!walker.moveToFirstChild()) {
michael@0:         return NS_OK;
michael@0:     }
michael@0: 
michael@0:     do {
michael@0:         const txXPathNode& node = walker.getCurrentPosition();
michael@0:         if (!(filterWS && txXPathNodeUtils::isText(node) &&
michael@0:               txXPathNodeUtils::isWhitespace(node))) {
michael@0:             rv = evalDescendants(aStep, node, aContext, resNodes);
michael@0:             NS_ENSURE_SUCCESS(rv, rv);
michael@0:         }
michael@0:     } while (walker.moveToNextSibling());
michael@0: 
michael@0:     return NS_OK;
michael@0: } //-- evalDescendants
michael@0: 
michael@0: Expr::ExprType
michael@0: PathExpr::getType()
michael@0: {
michael@0:   return PATH_EXPR;
michael@0: }
michael@0: 
michael@0: TX_IMPL_EXPR_STUBS_BASE(PathExpr, NODESET_RESULT)
michael@0: 
michael@0: Expr*
michael@0: PathExpr::getSubExprAt(uint32_t aPos)
michael@0: {
michael@0:     return aPos < mItems.Length() ? mItems[aPos].expr.get() : nullptr;
michael@0: }
michael@0: void
michael@0: PathExpr::setSubExprAt(uint32_t aPos, Expr* aExpr)
michael@0: {
michael@0:     NS_ASSERTION(aPos < mItems.Length(), "setting bad subexpression index");
michael@0:     mItems[aPos].expr.forget();
michael@0:     mItems[aPos].expr = aExpr;
michael@0: }
michael@0: 
michael@0: 
michael@0: bool
michael@0: PathExpr::isSensitiveTo(ContextSensitivity aContext)
michael@0: {
michael@0:     if (mItems[0].expr->isSensitiveTo(aContext)) {
michael@0:         return true;
michael@0:     }
michael@0: 
michael@0:     // We're creating a new node/nodeset so we can ignore those bits.
michael@0:     Expr::ContextSensitivity context =
michael@0:         aContext & ~(Expr::NODE_CONTEXT | Expr::NODESET_CONTEXT);
michael@0:     if (context == NO_CONTEXT) {
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     uint32_t i, len = mItems.Length();
michael@0:     for (i = 0; i < len; ++i) {
michael@0:         NS_ASSERTION(!mItems[i].expr->isSensitiveTo(Expr::NODESET_CONTEXT),
michael@0:                      "Step cannot depend on nodeset-context");
michael@0:         if (mItems[i].expr->isSensitiveTo(context)) {
michael@0:             return true;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     return false;
michael@0: }
michael@0: 
michael@0: #ifdef TX_TO_STRING
michael@0: void
michael@0: PathExpr::toString(nsAString& dest)
michael@0: {
michael@0:     if (!mItems.IsEmpty()) {
michael@0:         NS_ASSERTION(mItems[0].pathOp == RELATIVE_OP,
michael@0:                      "First step should be relative");
michael@0:         mItems[0].expr->toString(dest);
michael@0:     }
michael@0:     
michael@0:     uint32_t i, len = mItems.Length();
michael@0:     for (i = 1; i < len; ++i) {
michael@0:         switch (mItems[i].pathOp) {
michael@0:             case DESCENDANT_OP:
michael@0:                 dest.AppendLiteral("//");
michael@0:                 break;
michael@0:             case RELATIVE_OP:
michael@0:                 dest.Append(char16_t('/'));
michael@0:                 break;
michael@0:         }
michael@0:         mItems[i].expr->toString(dest);
michael@0:     }
michael@0: }
michael@0: #endif