synchronizedsymboltable.java

来自「JAVA的一些源码 JAVA2 STANDARD EDITION DEVELO」· Java 代码 · 共 168 行

/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 2000-2002 The Apache Software Foundation.  All rights
 * reserved.
 *
 * 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.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Xerces" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache",
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 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 1999, International
 * Business Machines, Inc., http://www.apache.org.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

package com.sun.org.apache.xerces.internal.util;

/**
 * Synchronized symbol table.
 *
 * This class moved into the util package since it's needed by multiple
 * other classes (CachingParserPool, XMLGrammarCachingConfiguration).
 *
 * @author Andy Clark, IBM
 * @version $Id: SynchronizedSymbolTable.java,v 1.2 2002/08/09 15:18:19 neilg Exp $
 */

public final class SynchronizedSymbolTable
    extends SymbolTable {
        
    //
    // Data
    //

    /** Main symbol table. */
    protected SymbolTable fSymbolTable;

    //
    // Constructors
    //

    /** Constructs a synchronized symbol table. */
    public SynchronizedSymbolTable(SymbolTable symbolTable) {
        fSymbolTable = symbolTable;
    } // <init>(SymbolTable) 

    // construct synchronized symbol table of default size
    public SynchronizedSymbolTable() {
        fSymbolTable = new SymbolTable();
    } // init()

    // construct synchronized symbol table of given size
    public SynchronizedSymbolTable(int size) {
        fSymbolTable = new SymbolTable(size);
    } // init(int)

    //
    // SymbolTable methods
    //
        
    /**
     * Adds the specified symbol to the symbol table and returns a
     * reference to the unique symbol. If the symbol already exists, 
     * the previous symbol reference is returned instead, in order
     * guarantee that symbol references remain unique.
     * 
     * @param symbol The new symbol.
     */
    public String addSymbol(String symbol) {

        synchronized (fSymbolTable) {
            return fSymbolTable.addSymbol(symbol);
        }

    } // addSymbol(String)

    /**
     * Adds the specified symbol to the symbol table and returns a
     * reference to the unique symbol. If the symbol already exists, 
     * the previous symbol reference is returned instead, in order
     * guarantee that symbol references remain unique.
     * 
     * @param buffer The buffer containing the new symbol.
     * @param offset The offset into the buffer of the new symbol.
     * @param length The length of the new symbol in the buffer.
     */
    public String addSymbol(char[] buffer, int offset, int length) {

        synchronized (fSymbolTable) {
            return fSymbolTable.addSymbol(buffer, offset, length);
        }

    } // addSymbol(char[],int,int):String

    /** 
     * Returns true if the symbol table already contains the specified
     * symbol.
     *
     * @param symbol The symbol to look for.
     */
    public boolean containsSymbol(String symbol) {

        synchronized (fSymbolTable) {
            return fSymbolTable.containsSymbol(symbol);
        }

    } // containsSymbol(String):boolean

    /** 
     * Returns true if the symbol table already contains the specified
     * symbol.
     *
     * @param buffer The buffer containing the symbol to look for.
     * @param offset The offset into the buffer.
     * @param length The length of the symbol in the buffer.
     */
    public boolean containsSymbol(char[] buffer, int offset, int length) {

        synchronized (fSymbolTable) {
            return fSymbolTable.containsSymbol(buffer, offset, length);
        }

    } // containsSymbol(char[],int,int):boolean

} // class SynchronizedSymbolTable