add ShardingHook.

/*

 * Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You 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.shardingsphere.core.hook;

import org.apache.shardingsphere.core.metadata.table.ShardingTableMetaData;

import org.apache.shardingsphere.core.route.SQLRouteResult;

/**

 * Sharding hook.

 *

 * @author zhaojun

 */

public interface ShardingHook {

    /**

     * Handle when sharding started.

     *

     * @param sql SQL to be sharding

     */

    void start(String sql);

    /**

     * Handle when sharding finished success.

     *

     * @param sqlRouteResult sql route result

     * @param shardingTableMetaData sharding table meta data

     */

    void finishSuccess(SQLRouteResult sqlRouteResult, ShardingTableMetaData shardingTableMetaData);

    /**

     * Handle when sharding finished failure.

     * 

     * @param cause failure cause

     */

    void finishFailure(Exception cause);

}