/*
 * Copyright 2006 the original author or authors.
 * 
 * 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.wamblee.crawler.kiss.scheduling;

/**
 * Interface to the scheduler specific for working with the crawler. 
 */
public interface CrawlerScheduler {
    
    /**
     * Initializes the scheduler. 
     * @throws Exception In case of problems.
     */
    void initialize() throws Exception;
    
    /**
     * Checks if the crawler is running. 
     * @return True iff the crawler is running. 
     * @throws Exception In case of problems. 
     */
    boolean isCrawlerRunning() throws Exception; 
 
    /**
     * Schedules the crawler for immediate execution. 
     * @throws Exception In case of problems. 
     */
    void scheduleNow() throws Exception; 
    
    /**
     * Shuts down the scheduler. 
     * @throws Exception In case of problems. 
     */
    void shutdown() throws Exception; 
}