/*
* 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 SoftwareFoundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*/
package com.caucho.xpath;
import com.caucho.util.FreeList;
import com.caucho.xml.XmlUtil;
import com.caucho.xpath.expr.ObjectVar;
import com.caucho.xpath.expr.Var;
import com.caucho.xpath.pattern.AbstractPattern;
import com.caucho.xpath.pattern.NodeIterator;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
/**
* Global and local variable environment. The April XSLT draft introduces
* global and local variables. The Env class contains those bindings.
*
* <p>Because this class exists only to support XSL, it makes a number
* of assumptions that would be invalid for a typical API. Specifically,
* the variable names <font color='red'>must</font> be interned strings, i.e.
* variable matching uses '==', not equals.
*
* <p>Local variables are handled like a stack. They are pushed and
* popped as necessary. The top variables shadow bottom variables.
*
* <p>In other words, although the API somewhat resembles a HashMap,
* it can't be used as a generic hash map.
*/
public class Env implements ExprEnvironment {
static FreeList<Env> _freeList = new FreeList<Env>(32);
HashMap _ids;
HashMap _idCache;
Element _lastElement;
HashMap<String,Var> _globals; // = new HashMap();
HashMap _functions;
HashMap _cache;
String []_varKeys;
Var []_varValues;
int _varSize;
private Node _currentNode;
private Node _contextNode;
private int _positionIndex;
private boolean _hasMorePositions;
private int _useCount;
private Env _parent;
private Env _root;
private ExprEnvironment _exprEnv;
private AbstractPattern _select;
private int _position;
private int _size;
private StylesheetEnv _stylesheetEnv;
private VarEnv _varEnv;
static Env create()
{
Env env = null; // (Env) freeList.allocate();
if (env == null)
env = new Env();
env._root = env;
return env;
}
public void setStylesheetEnv(StylesheetEnv stylesheetEnv)
{
_stylesheetEnv = stylesheetEnv;
}
public StylesheetEnv getStylesheetEnv()
{
for (Env env = this; env != null; env = env._parent)
if (env._stylesheetEnv != null)
return env._stylesheetEnv;
return null;
}
/**
* Sets the variable environment.
*/
public void setVarEnv(VarEnv varEnv)
{
_varEnv = varEnv;
}
/**
* Returns the variable environment.
*/
public VarEnv getVarEnv()
{
return _varEnv;
}
/**
* Initialize the XPath environment with values from the parent.
*/
void init(Env parent)
{
_parent = parent;
_root = parent._root;
}
/**
* Initialize the XPath environment with a context and a select node.
*/
void init(Env parent, AbstractPattern select, Node currentNode)
{
_parent = parent;
_root = parent._root;
_select = select;
_currentNode = currentNode;
}
/**
* Initialize the XPath environment with values from the parent.
*/
void initMacro(Env parent)
{
_parent = parent;
_root = parent._root;
_select = parent._select;
_stylesheetEnv = parent._stylesheetEnv;
_exprEnv = parent._exprEnv;
_currentNode = parent._currentNode;
_contextNode = parent._contextNode;
_position = parent._position;
_size = parent._size;
_positionIndex = 0;
_hasMorePositions = false;
_useCount = 0;
}
/**
* Clears all values in the local environment.
*/
public void clear()
{
if (true)
return;
_useCount++;
if (_ids != null) {
_ids.clear();
_idCache.clear();
}
while (_varSize-- > 0) {
_varKeys[_varSize] = null;
_varValues[_varSize] = null;
}
_varSize = 0;
_lastElement = null;
_globals.clear();
_functions = null;
_cache = null;
_currentNode = null;
_contextNode = null;
_parent = null;
_select = null;
_size = 0;
_position = 0;
_positionIndex = 0;
_hasMorePositions = false;
}
/**
* Returns the parent envivonment.
*/
Env getParent()
{
return _parent;
}
/**
* Returns the current number of local variables.
*/
public int getVarSize()
{
return _varSize;
}
/**
* Sets the current number of local variables (popping, them).
*/
public void setVarSize(int size)
{
if (_varKeys == null)
return;
for (; _varSize > size; _varSize--) {
_varSize--;
_varKeys[_varSize] = null;
_varValues[_varSize] = null;
}
}
/**
* Returns the value associated with name.
*
* <p><em>name must be interned</em>
*/
public Var getVar(String name)
{
for (int i = _varSize - 1; i >= 0; i--) {
if (_varKeys[i] == name)
return _varValues[i];
}
if (_root._globals != null) {
Var var = _root._globals.get(name);
if (var != null)
return var;
}
if (_root._varEnv != null)
return _root._varEnv.getVar(name);
else
return null;
}
/**
* Adds the value associated with name.
*
* <p><em>name must be interned</em>
*/
public int addVar(String name, Object value)
{
_useCount++;
if (value instanceof Iterator)
value = iteratorToList((Iterator) value);
if (! (value instanceof Var))
value = new ObjectVar(value);
return addVar(name, (Var) value);
}
/**
* Sets the value associated with name.
*
* <p><em>name must be interned</em>
*/
public void setVar(String name, Object value)
{
_useCount++;
if (value instanceof Iterator)
value = iteratorToList((Iterator) value);
if (! (value instanceof Var))
value = new ObjectVar(value);
for (int i = _varSize - 1; i >= 0; i--) {
if (_varKeys[i] == name) {
_varValues[i] = (Var) value;
return;
}
}
addVar(name, (Var) value);
}
/**
* Adds the value associated with name.
*
* <p><em>name must be interned</em>
*/
public int addVar(String name, Var value)
{
_useCount++;
if (_varKeys == null) {
_varKeys = new String[16];
_varValues = new Var[16];
}
else if (_varSize == _varKeys.length) {
String []newKeys = new String[2 * _varKeys.length];
Var []newValues = new Var[2 * _varKeys.length];
System.arraycopy(_varKeys, 0, newKeys, 0, _varSize);
System.arraycopy(_varValues, 0, newValues, 0, _varSize);
_varKeys = newKeys;
_varValues = newValues;
}
_varKeys[_varSize] = name;
_varValues[_varSize] = value;
_varSize++;
return _varSize - 1;
}
/**
* Pops the last count vars from the local stack.
*/
public void popVars(int count)
{
_useCount++;
if (_varKeys == null)
return;
for (; count > 0 && _varSize > 0; count--) {
_varSize--;
_varKeys[_varSize] = null;
_varValues[_varSize].free();
_varValues[_varSize] = null;
}
}
/**
* Returns the top of the stack.
*/
public int getTop()
{
return _varSize;
}
/**
* Pops the last count vars from the local stack.
*/
public void popToTop(int top)
{
_useCount++;
if (_varKeys == null)
return;
while (top < _varSize) {
_varSize--;
_varKeys[_varSize] = null;
_varValues[_varSize].free();
_varValues[_varSize] = null;
}
}
/**
* Sets a global variable.
*/
public void setGlobal(String name, Object value)
{
_useCount++;
Var var = null;
if (value instanceof Iterator)
value = iteratorToList((Iterator) value);
if (value instanceof Var)
var = (Var) value;
else
var = new ObjectVar(value);
if (_root._globals == null)
_root._globals = new HashMap<String,Var>();
_root._globals.put(name, var);
}
/**
* Converts an iterator to an array list
*/
private ArrayList iteratorToList(Iterator iter)
{
ArrayList list = new ArrayList();
while (iter.hasNext())
list.add(iter.next());
return list;
}
/**
* Sets the extension function library
*
* @param function new function library
* @return old function library
*/
public HashMap setFunctions(HashMap functions)
{
HashMap old = _functions;
_functions = functions;
return old;
}
/**
* Adds and extension function
*
* @param function new function library
* @return old function library
*/
public void addFunction(String name, Object fun)
{
if (_functions == null)
_functions = new HashMap();
_functions.put(name, fun);
}
/**
* Returns the named function.
*/
public XPathFun getFunction(String name)
{
if (_root._functions == null)
return null;
else
return (XPathFun) _root._functions.get(name);
}
/**
* Returns true if there are more positions() needed to iterate through.
*/
public boolean hasMorePositions()
{
return _hasMorePositions;
}
/**
* Set true if there are more positions() needed to iterate through.
*
* @param more if true, there are more positions to iterate through.
*
* @return the old more-position value.
*/
public boolean setMorePositions(boolean more)
{
boolean old = _hasMorePositions;
_hasMorePositions = more;
return old;
}
/*
* The position index is used for patterns which have multiple position()s
* for the same node. See FilterPattern for a more detailed description.
*
* @param index the new position index.
*
* @return the old position index.
*/
public int setPositionIndex(int index)
{
int old = _positionIndex;
_positionIndex = index;
return old;
}
/*
* Returns the position index is used for patterns which have
* multiple position()s for the same node. See FilterPattern for a
* more detailed description.
*/
public int getPositionIndex()
{
return _positionIndex;
}
/**
* Gets the current node.
*/
public Node getCurrentNode()
{
return _currentNode;
}
/**
* Sets the current node.
*/
public void setCurrentNode(Node node)
{
_currentNode = node;
}
/**
* Sets the selection context
*/
public AbstractPattern setSelect(Node node, AbstractPattern select)
{
AbstractPattern oldSelect = _select;
_contextNode = node;
_select = select;
_position = 0;
return oldSelect;
}
public AbstractPattern getSelect()
{
return _select;
}
/**
* Sets the selection context
*/
public ExprEnvironment setExprEnv(ExprEnvironment exprEnv)
{
ExprEnvironment oldExprEnv = _exprEnv;
_exprEnv = exprEnv;
return oldExprEnv;
}
public ExprEnvironment getExprEnv()
{
return _exprEnv;
}
/**
* Gets the context node.
*/
public Node getContextNode()
{
return _contextNode;
}
/**
* Sets the context node.
*/
public Node setContextNode(Node contextNode)
{
Node oldNode = _contextNode;
_contextNode = contextNode;
return oldNode;
}
/**
* Returns the position of the context node.
*/
public int getContextPosition()
{
if (_exprEnv != null)
return _exprEnv.getContextPosition();
if (_position > 0)
return _position;
if (_contextNode == null || _currentNode == null)
return 0;
if (_select != null) {
try {
NodeIterator iter = _select.select(_contextNode, this);
Node child;
while ((child = iter.nextNode()) != null && child != _currentNode) {
}
return iter.getContextPosition();
} catch (Exception e) {
}
}
Node child = _contextNode.getFirstChild();
int pos = 1;
for (;
child != null && child != _currentNode;
child = child.getNextSibling()) {
pos++;
}
return pos;
}
/**
* Returns the number of nodes in the context list.
*/
public int getContextSize()
{
if (_exprEnv != null)
return _exprEnv.getContextSize();
if (_size > 0)
return _size;
if (_contextNode == null || _currentNode == null)
return 0;
if (_select != null) {
try {
NodeIterator iter = _select.select(_contextNode, this);
Node child;
while ((child = iter.nextNode()) != null && child != _currentNode) {
}
return iter.getContextSize();
} catch (Exception e) {
}
}
Node child = _contextNode.getFirstChild();
int pos = 0;
for (;
child != null;
child = child.getNextSibling())
pos++;
return pos;
}
/**
* Returns a document for creating nodes.
*/
public Document getOwnerDocument()
{
return null;
}
/**
* Returns the given system property.
*/
public Object systemProperty(String namespaceURI, String localName)
{
return null;
}
/**
* Returns the string-value of the node.
*/
public String stringValue(Node node)
{
return XmlUtil.textValue(node);
}
/*
* Returns the position() value. Note, this is not the same as
* positionIndex.
*/
public void setPosition(int position)
{
_position = position;
}
public int setContextPosition(int position)
{
int oldPosition = _position;
_position = position;
return oldPosition;
}
/**
* Sets the context size to a know value.
*/
public int setContextSize(int size)
{
int oldSize = _size;
_size = size;
return oldSize;
}
public Object getCache(Object key)
{
if (_root._cache == null)
return null;
else
return _root._cache.get(key);
}
public void setCache(Object key, Object value)
{
if (_root._cache == null)
_root._cache = new HashMap();
_root._cache.put(key, value);
}
public int getUseCount()
{
return _useCount;
}
public void free()
{
_root = null;
_parent = null;
_select = null;
_exprEnv = null;
_stylesheetEnv = null;
if (_ids != null) {
_ids.clear();
_idCache.clear();
}
while (_varSize-- > 0) {
_varKeys[_varSize] = null;
_varValues[_varSize] = null;
}
_varSize = 0;
_lastElement = null;
if (_globals != null)
_globals.clear();
_functions = null;
_cache = null;
_currentNode = null;
_contextNode = null;
_size = 0;
_position = 0;
_positionIndex = 0;
_hasMorePositions = false;
_freeList.free(this);
}
}