/*   
 *  Copyright 1999-2004 The Apache Sofware 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.
 */

package org.apache.tomcat.util.hooks;

import java.util.Vector;

/** Hooks support. Hooks implement a chain-of-command pattern, and
 * are commonly used in most web servers as a mechanism of extensibility.
 *
 * This class doesn't deal with hook invocation - the program is expected
 * to use interfaces or base classes with the hooks beeing methods that
 * are invoked. Reflection-based invocation is very expensive and shouldn't 
 * be used.
 * 
 * The Hooks class will provide support for registering and maintaining
 * a list of modules implementing each hook.
 *
 * The module can be added automatically to the right lists by using
 * introspection ( if the module implements a certain method, it'll
 * be added to the chain for the hook with the same name ). It is also
 * possible for a module to explicitely register hooks.
 *
 * This class is modeled after Apache2.0 hooks - most web servers are using
 * this pattern, but so far A2.0 has the most flexible and powerfull
 * implementation
 */
public class Hooks {
    static org.apache.commons.logging.Log logger =
	org.apache.commons.logging.LogFactory.getLog(Hooks.class);

    public static final int INITIAL_HOOKS=24;
    int hookCount;
    String hookNames[];
    Vector hooksV[];

    Object hooks[][];

    Vector allModulesV;
    Object allModules[];

    private static final int dL=0;

    public Hooks() {
	this.hookCount=INITIAL_HOOKS; // XXX TODO: resizing
	hooksV=new Vector[hookCount];
	for( int i=0; i