// Copyright 2012 Citrix Systems, Inc. Licensed under the
// Apache License, Version 2.0 (the "License"); you may not use this
// file except in compliance with the License.  Citrix Systems, Inc.
// reserves all rights not expressly granted by 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.
// 
// Automatically generated by addcopyright.py at 04/03/2012
package com.cloud.cluster;


/**
 * TaskManager helps business logic deal with clustering failover.
 * Say you're writing code that introduces an inconsistent state over
 * of your operation?  Who will come back to cleanup this state?  TaskManager
 * with different content during your process.  If the server dies, TaskManager
 * running elsewhere.  If there are no clustered servers, then TaskManager will
 * cleanup when the dead server resumes.
 *
 */
public interface CheckPointManager {
    /**
     * responsible for cleaning up.
     * 
     * @param context context information to be stored.
     * @return Check point id.
     */
    long pushCheckPoint(CleanupMaid context);
    
    /**
     * update the task with new context
     * @param taskId
     * @param updatedContext new updated context.
     */
    void updateCheckPointState(long taskId, CleanupMaid updatedContext);
    
    
    /**
     * removes the task as it is completed.
     * 
     * @param taskId
     */
    void popCheckPoint(long taskId);
}