keyindex.java

java1.6众多例子参考

/*
 * Copyright 2001-2006 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: KeyIndex.java,v 1.6 2006/06/19 19:49:02 spericas Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.dom;

import java.util.StringTokenizer;

import com.sun.org.apache.xalan.internal.xsltc.DOM;
import com.sun.org.apache.xalan.internal.xsltc.DOMEnhancedForDTM;
import com.sun.org.apache.xalan.internal.xsltc.runtime.BasisLibrary;
import com.sun.org.apache.xalan.internal.xsltc.runtime.Hashtable;
import com.sun.org.apache.xalan.internal.xsltc.util.IntegerArray;

import com.sun.org.apache.xml.internal.dtm.Axis;
import com.sun.org.apache.xml.internal.dtm.DTM;
import com.sun.org.apache.xml.internal.dtm.DTMAxisIterator;
import com.sun.org.apache.xml.internal.dtm.ref.DTMAxisIteratorBase;

/**
 * Stores mappings of key values or IDs to DTM nodes.
 * <em>Use of an instance of this class as a {@link DTMAxisIterator} is
 * <b>deprecated.</b></em>
 * @author Morten Jorgensen
 * @author Santiago Pericas-Geertsen
 */
public class KeyIndex extends DTMAxisIteratorBase {

    /**
     * A mapping between values and nodesets for the current document.  Used
     * only while building keys.
     */
    private Hashtable _index;

    /**
     * The document node currently being processed.  Used only while building
     * keys.
     */
    private int _currentDocumentNode = DTM.NULL;

    /**
     * A mapping from a document node to the mapping between values and nodesets
     */
    private Hashtable _rootToIndexMap = new Hashtable();

    /**
     * The node set associated to the current value passed
     * to lookupKey();
     */
    private IntegerArray _nodes = null;

    /**
     * The XSLTC DOM object if this KeyIndex is being used to implement the
     * id() function.
     */
    private DOM        _dom;
    
    private DOMEnhancedForDTM    _enhancedDOM;

    /**
     * Store position after call to setMark()
     */
    private int _markedPosition = 0;

    public KeyIndex(int dummy) {
    }

    public void setRestartable(boolean flag) {
    }

    /**
     * Adds a node to the node list for a given value. Nodes will
     * always be added in document order.
     */
    public void add(Object value, int node, int rootNode) {
        if (_currentDocumentNode != rootNode) {
            _currentDocumentNode = rootNode;
            _index = new Hashtable();
            _rootToIndexMap.put(new Integer(rootNode), _index);
        }

        IntegerArray nodes = (IntegerArray) _index.get(value);

        if (nodes == null) {
             nodes = new IntegerArray();
            _index.put(value, nodes);
            nodes.add(node);

        // Because nodes are added in document order,
        // duplicates can be eliminated easily at this stage.
        } else if (node != nodes.at(nodes.cardinality() - 1)) {
            nodes.add(node);
        }
    }

    /**
     * Merge the current value's nodeset set by lookupKey() with _nodes.
     * @deprecated
     */
    public void merge(KeyIndex other) {
	if (other == null) return;

	if (other._nodes != null) {
	    if (_nodes == null) {
		_nodes = (IntegerArray)other._nodes.clone();
	    }
	    else {
		_nodes.merge(other._nodes);
	    }
	}
    }

    /**
     * This method must be called by the code generated by the id() function
     * prior to returning the node iterator. The lookup code for key() and
     * id() differ in the way the lookup value can be whitespace separated
     * list of tokens for the id() function, but a single string for the
     * key() function.
     * @deprecated
     */
    public void lookupId(Object value) {
	// Clear _nodes array
	_nodes = null;

	final StringTokenizer values = new StringTokenizer((String) value,
                                                           " \n\t");
	while (values.hasMoreElements()) {
            final String token = (String) values.nextElement();
	    IntegerArray nodes = (IntegerArray) _index.get(token);

            if (nodes == null && _enhancedDOM != null
                && _enhancedDOM.hasDOMSource()) {
                nodes = getDOMNodeById(token);
            }

	    if (nodes == null) continue;

	    if (_nodes == null) {
		 nodes = (IntegerArray)nodes.clone();
		_nodes = nodes;
	    }
	    else {
		_nodes.merge(nodes);
	    }
	}
    }

    /**
     * Return an IntegerArray for the DOM Node which has the given id.
     * 
     * @param id The id
     * @return A IntegerArray representing the Node whose id is the given value.
     */
    public IntegerArray getDOMNodeById(String id) {
        IntegerArray nodes = null;

        if (_enhancedDOM != null) {
            int ident = _enhancedDOM.getElementById(id);

            if (ident != DTM.NULL) {
                Integer root = new Integer(_enhancedDOM.getDocument());
                Hashtable index = (Hashtable) _rootToIndexMap.get(root);

                if (index == null) {
                    index = new Hashtable();
                    _rootToIndexMap.put(root, index);
                } else {
                    nodes = (IntegerArray) index.get(id);
                }

                if (nodes == null) {
                    nodes = new IntegerArray();
                    index.put(id, nodes);
                }

                nodes.add(_enhancedDOM.getNodeHandle(ident));
            }
        }

        return nodes;
    }
    
    /**
     * <p>This method must be called by the code generated by the key() function
     * prior to returning the node iterator.</p>
     * <p><em>Use of an instance of this class as a {@link DTMAxisIterator} is
     * <b>deprecated.</b></em></p>
     * @deprecated
     */
    public void lookupKey(Object value) {
        IntegerArray nodes = (IntegerArray) _index.get(value);
        _nodes = (nodes != null) ? (IntegerArray) nodes.clone() : null;
        _position = 0;
    }

    /** 
     * <p>Callers should not call next() after it returns END.</p>
     * <p><em>Use of an instance of this class as a {@link DTMAxisIterator} is
     * <b>deprecated.</b></em></p>
     * @deprecated
     */
    public int next() {
	if (_nodes == null) return DTMAxisIterator.END;

	return (_position < _nodes.cardinality()) ? 
	    _dom.getNodeHandle(_nodes.at(_position++)) : DTMAxisIterator.END;
    }

    /**
     * Given a context node and the argument to the XPath <code>id</code>
     * function, checks whether the context node is in the set of nodes that
     * results from that reference to the <code>id</code> function.  This is
     * used in the implementation of <code>id</code> patterns.
     *
     * @param node The context node
     * @param value The argument to the <code>id</code> function
     * @return <code>1</code> if the context node is in the set of nodes
     *         returned by the reference to the <code>id</code> function;
     *         <code>0</code>, otherwise
     */
    public int containsID(int node, Object value) {
        final String string = (String)value;
        int rootHandle = _dom.getAxisIterator(Axis.ROOT)
                                 .setStartNode(node).next();

        // Get the mapping table for the document containing the context node
        Hashtable index =
            (Hashtable) _rootToIndexMap.get(new Integer(rootHandle));

        // Split argument to id function into XML whitespace separated tokens
        final StringTokenizer values = new StringTokenizer(string, " \n\t");

        while (values.hasMoreElements()) {
            final String token = (String) values.nextElement();
            IntegerArray nodes = null;

            if (index != null) {
                nodes = (IntegerArray) index.get(token);
            }

            // If input was from W3C DOM, use DOM's getElementById to do
            // the look-up.
            if (nodes == null && _enhancedDOM != null
                && _enhancedDOM.hasDOMSource()) {
                nodes = getDOMNodeById(token);	
            }

            // Did we find the context node in the set of nodes?
            if (nodes != null && nodes.indexOf(node) >= 0) {
                return 1;
            }
        }

        // Didn't find the context node in the set of nodes returned by id
        return 0;
    }

    /**
     * <p>Given a context node and the second argument to the XSLT
     * <code>key</code> function, checks whether the context node is in the
     * set of nodes that results from that reference to the <code>key</code>
     * function.  This is used in the implementation of key patterns.</p>
     * <p>This particular {@link KeyIndex} object is the result evaluating the
     * first argument to the <code>key</code> function, so it's not taken into
     * any further account.</p>
     *
     * @param node The context node
     * @param value The second argument to the <code>key</code> function
     * @return <code>1</code> if and only if the context node is in the set of
     *         nodes returned by the reference to the <code>key</code> function;
     *         <code>0</code>, otherwise
     */
    public int containsKey(int node, Object value) {
        int rootHandle = _dom.getAxisIterator(Axis.ROOT)
                                 .setStartNode(node).next();

        // Get the mapping table for the document containing the context node
        Hashtable index =
                    (Hashtable) _rootToIndexMap.get(new Integer(rootHandle));

        // Check whether the context node is present in the set of nodes
        // returned by the key function
        if (index != null) {
            final IntegerArray nodes = (IntegerArray) index.get(value);
            return (nodes != null && nodes.indexOf(node) >= 0) ? 1 : 0;