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/*
* Copyright (C) 2005 Frerich Raabe <raabe@kde.org>
* Copyright (C) 2006, 2009 Apple Inc.
* Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "XPathPath.h"
#if ENABLE(XPATH)
#include "Document.h"
#include "XPathPredicate.h"
#include "XPathStep.h"
#include "XPathValue.h"
namespace WebCore {
namespace XPath {
Filter::Filter(Expression* expr, const Vector<Predicate*>& predicates)
: m_expr(expr), m_predicates(predicates)
{
setIsContextNodeSensitive(m_expr->isContextNodeSensitive());
setIsContextPositionSensitive(m_expr->isContextPositionSensitive());
setIsContextSizeSensitive(m_expr->isContextSizeSensitive());
}
Filter::~Filter()
{
delete m_expr;
deleteAllValues(m_predicates);
}
Value Filter::evaluate() const
{
Value v = m_expr->evaluate();
NodeSet& nodes = v.modifiableNodeSet();
nodes.sort();
EvaluationContext& evaluationContext = Expression::evaluationContext();
for (unsigned i = 0; i < m_predicates.size(); i++) {
NodeSet newNodes;
evaluationContext.size = nodes.size();
evaluationContext.position = 0;
for (unsigned j = 0; j < nodes.size(); j++) {
Node* node = nodes[j];
evaluationContext.node = node;
++evaluationContext.position;
if (m_predicates[i]->evaluate())
newNodes.append(node);
}
nodes.swap(newNodes);
}
return v;
}
LocationPath::LocationPath()
: m_absolute(false)
{
setIsContextNodeSensitive(true);
}
LocationPath::~LocationPath()
{
deleteAllValues(m_steps);
}
Value LocationPath::evaluate() const
{
EvaluationContext& evaluationContext = Expression::evaluationContext();
EvaluationContext backupContext = evaluationContext;
// For absolute location paths, the context node is ignored - the
// document's root node is used instead.
Node* context = evaluationContext.node.get();
if (m_absolute && context->nodeType() != Node::DOCUMENT_NODE)
context = context->ownerDocument();
NodeSet nodes;
nodes.append(context);
evaluate(nodes);
evaluationContext = backupContext;
return Value(nodes, Value::adopt);
}
void LocationPath::evaluate(NodeSet& nodes) const
{
bool resultIsSorted = nodes.isSorted();
for (unsigned i = 0; i < m_steps.size(); i++) {
Step* step = m_steps[i];
NodeSet newNodes;
HashSet<Node*> newNodesSet;
bool needToCheckForDuplicateNodes = !nodes.subtreesAreDisjoint() || (step->axis() != Step::ChildAxis && step->axis() != Step::SelfAxis
&& step->axis() != Step::DescendantAxis && step->axis() != Step::DescendantOrSelfAxis && step->axis() != Step::AttributeAxis);
if (needToCheckForDuplicateNodes)
resultIsSorted = false;
// This is a simplified check that can be improved to handle more cases.
if (nodes.subtreesAreDisjoint() && (step->axis() == Step::ChildAxis || step->axis() == Step::SelfAxis))
newNodes.markSubtreesDisjoint(true);
for (unsigned j = 0; j < nodes.size(); j++) {
NodeSet matches;
step->evaluate(nodes[j], matches);
if (!matches.isSorted())
resultIsSorted = false;
for (size_t nodeIndex = 0; nodeIndex < matches.size(); ++nodeIndex) {
Node* node = matches[nodeIndex];
if (!needToCheckForDuplicateNodes || newNodesSet.add(node).second)
newNodes.append(node);
}
}
nodes.swap(newNodes);
}
nodes.markSorted(resultIsSorted);
}
void LocationPath::appendStep(Step* step)
{
unsigned stepCount = m_steps.size();
if (stepCount) {
bool dropSecondStep;
optimizeStepPair(m_steps[stepCount - 1], step, dropSecondStep);
if (dropSecondStep) {
delete step;
return;
}
}
step->optimize();
m_steps.append(step);
}
void LocationPath::insertFirstStep(Step* step)
{
if (m_steps.size()) {
bool dropSecondStep;
optimizeStepPair(step, m_steps[0], dropSecondStep);
if (dropSecondStep) {
delete m_steps[0];
m_steps[0] = step;
return;
}
}
step->optimize();
m_steps.insert(0, step);
}
Path::Path(Filter* filter, LocationPath* path)
: m_filter(filter)
, m_path(path)
{
setIsContextNodeSensitive(filter->isContextNodeSensitive());
setIsContextPositionSensitive(filter->isContextPositionSensitive());
setIsContextSizeSensitive(filter->isContextSizeSensitive());
}
Path::~Path()
{
delete m_filter;
delete m_path;
}
Value Path::evaluate() const
{
Value v = m_filter->evaluate();
NodeSet& nodes = v.modifiableNodeSet();
m_path->evaluate(nodes);
return v;
}
}
}
#endif // ENABLE(XPATH)