/**
* 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 com.leansoft.luxun.producer.async;
import java.util.List;
import java.util.Properties;
/**
* Callback handler APIs for use in the async producer. The purpose is to
* give the user some callback handlers to insert custom functionality at
* various stages as the data flows through the pipeline of the async
* producer
*
* @author bulldog
*
*/
public interface CallbackHandler<T> {
/**
* Initializes the callback handler using a Properties object
*
* @param properties properties used to initialize the callback handler
*/
void init(Properties properties);
/**
* Callback to process the data before it enters the batching queue of
* the asynchronous producer
*
* @param data the data sent to the producer
* @return the processed data that enters the queue
*/
QueueItem<T> beforeEnqueue(QueueItem<T> data);
/**
* Callback to process the data right after it enters the batching
* queue of the asynchronous producer
*
* @param data the data sent to the producer
* @param remainSize the size of the remained data in blocking queue
* @param added flag that indicates if the data was successfully added
* to the queue
*/
QueueItem<T> afterEnqueue(QueueItem<T> data, int remainSize, boolean added);
/**
* Callback to process the data item right after it has been dequeued
* by the background sender thread of the asynchronous producer
*
* @param data the data item dequeued from the async producer queue
* @return the processed list of data items that gets added to the data
* handled by the event handler
*/
List<QueueItem<T>> afterDequeuingExistingData(QueueItem<T> data);
/**
* Callback to process the batched data right before it is being sent
* by the handle API of the event handler
*
* @param data the batched data received by the event handler
* @return the processed batched data that gets sent by the handle()
* API of the event handler
*/
List<QueueItem<T>> beforeSendingData(List<QueueItem<T>> data);
/**
* Callback to process the last batch of data right before the producer
* send thread is shutdown
*
* @return the last batch of data that is sent to the EventHandler
*/
List<QueueItem<T>> lastBatchBeforeClose();
/**
* Callback to process when the connection is refused
*
* @param broker the refused broker info
* @param remainedItems the batched data that didn't send to the broker
*/
void connectionRefused(String broker, List<QueueItem<T>> remainedItems);
/**
* Cleans up and shuts down the callback handler
*/
void close();
/**
* Cleans up and shuts down the callback handler
*
* @param remainedItems the batched data that didn't send to the broker
*/
void close(List<QueueItem<T>> remainedItems);
}