/*
* Copyright (c) 1998-2010 Caucho Technology -- all rights reserved
*
* This file is part of Resin(R) Open Source
*
* Each copy or derived work must preserve the copyright notice and this
* notice unmodified.
*
* Resin Open Source is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Resin Open Source is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
* of NON-INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with Resin Open Source; if not, write to the
*
* Free Software Foundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Nam Nguyen
*/
package com.caucho.quercus.lib.dom;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.Map;
import javax.xml.namespace.NamespaceContext;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import com.caucho.quercus.QuercusModuleException;
import com.caucho.quercus.annotation.Optional;
import com.caucho.quercus.env.Env;
import com.caucho.util.LruCache;
import com.caucho.xpath.Expr;
public class DOMXPath
{
private DOMNamespaceContext _context;
private DOMDocument _document;
public static DOMXPath __construct(Env env, DOMDocument document)
{
return new DOMXPath(env, document);
}
private DOMXPath(Env env, DOMDocument document)
{
_document = document;
}
public Object evaluate(Env env,
String expression)
{
Node node = _document.getDelegate();
NodeList nodeList = (NodeList) query(env, expression, node);
if (nodeList.getLength() == 1) {
return _document.wrap(nodeList.item(0));
}
else
return _document.wrap(nodeList);
}
public DOMNodeList query(Env env,
String expression,
@Optional DOMNode<Node> contextNode)
{
Node node;
if (contextNode != null)
node = contextNode.getDelegate();
else
node = _document.getDelegate();
NodeList nodeList = (NodeList) query(env, expression, node);
return _document.wrap(nodeList);
}
private NodeList query(Env env, String pattern, Node node)
{
// the JDKs xpath is extremely inefficient, causing benchmark
// problems with mediawiki
try {
Expr expr = com.caucho.xpath.XPath.parseExpr(pattern);
return (NodeList) expr.evalObject(node);
} catch (Exception e) {
throw new QuercusModuleException(e);
}
}
/*
private NodeList query(Env env, String pattern, Node node)
{
try {
if (_context == null) {
Quercus quercus = env.getQuercus();
ExpressionCache cache
= (ExpressionCache) quercus.getSpecial("caucho.domxpath.cache");
if (cache == null) {
cache = new ExpressionCache();
quercus.setSpecial("caucho.domxpath.cache", cache);
}
XPathExpression expr = cache.compile(pattern);
NodeList nodeList
= (NodeList) expr.evaluate(node, XPathConstants.NODESET);
cache.free(pattern, expr);
return nodeList;
}
else {
XPath xpath = (XPath) env.getSpecialValue("caucho.domxpath.xpath");
if (xpath == null) {
XPathFactory factory = XPathFactory.newInstance();
xpath = factory.newXPath();
env.setSpecialValue("caucho.domxpath.xpath", xpath);
}
xpath.setNamespaceContext(_context);
XPathExpression expr = xpath.compile(pattern);
NodeList nodeList
= (NodeList) expr.evaluate(node, XPathConstants.NODESET);
return nodeList;
}
}
catch (XPathExpressionException e) {
throw new QuercusModuleException(e);
}
}
*/
public boolean registerNamespace(String prefix, String namespaceURI)
{
if (_context == null)
_context = new DOMNamespaceContext();
_context.addNamespace(prefix, namespaceURI);
return true;
}
public class DOMNamespaceContext
implements NamespaceContext
{
private HashMap<String, LinkedHashSet<String>> _namespaceMap
= new HashMap<String, LinkedHashSet<String>>();
protected void addNamespace(String prefix, String namespaceURI)
{
LinkedHashSet<String> list = _namespaceMap.get(namespaceURI);
if (list == null) {
list = new LinkedHashSet<String>();
_namespaceMap.put(namespaceURI, list);
}
list.add(prefix);
}
public String getNamespaceURI(String prefix)
{
for (Map.Entry<String, LinkedHashSet<String>> entry
: _namespaceMap.entrySet()) {
if (entry.getValue().contains(prefix))
return entry.getKey();
}
return null;
}
public String getPrefix(String namespaceURI)
{
Iterator<String> iter = getPrefixes(namespaceURI);
if (iter != null)
return iter.next();
else
return null;
}
public Iterator<String> getPrefixes(String namespaceURI)
{
LinkedHashSet<String> prefixList = _namespaceMap.get(namespaceURI);
if (prefixList != null)
return prefixList.iterator();
else
return null;
}
}
static class ExpressionCache {
private final XPathFactory _factory = XPathFactory.newInstance();
private final LruCache<String,ExpressionEntry> _xpathCache
= new LruCache<String,ExpressionEntry>(1024);
XPathExpression compile(String pattern)
throws XPathExpressionException
{
ExpressionEntry entry = _xpathCache.get(pattern);
XPathExpression expr = null;
if (entry != null)
expr = entry.allocate();
if (expr == null) {
XPath xpath = _factory.newXPath();
expr = xpath.compile(pattern);
}
return expr;
}
void free(String pattern, XPathExpression expr)
{
ExpressionEntry entry = _xpathCache.get(pattern);
if (entry == null) {
entry = new ExpressionEntry();
_xpathCache.put(pattern, entry);
}
entry.free(expr);
}
}
static class ExpressionEntry {
private XPathExpression _expr;
XPathExpression allocate()
{
synchronized (this) {
XPathExpression expr = _expr;
_expr = null;
return expr;
}
}
void free(XPathExpression expr)
{
synchronized (this) {
_expr = expr;
}
}
}
}