package com.taobao.metamorphosis.client.consumer;
/**
* Message id cache to prevent duplicated messages for the same consumer group.
*
* @author dennis<killme2008@gmail.com>
* @since 1.4.6
*
*/
public interface MessageIdCache {
/**
* Added key value to cache
*
* @param key
* @param exists
*/
public void put(String key, Byte exists);
/**
* Get value from cache,it the item is exists,it must be returned.
*
* @param key
* @return
*/
public Byte get(String key);
}