org.apache.flink.streaming.runtime.io.BufferBlocker Maven / Gradle / Ivy
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* 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.flink.streaming.runtime.io;
import org.apache.flink.annotation.Internal;
import org.apache.flink.runtime.io.network.partition.consumer.BufferOrEvent;
import java.io.IOException;
/**
* The buffer blocker takes the buffers and events from a data stream and adds them in a sequence.
* After a number of elements have been added, the blocker can "roll over": It presents the added
* elements as a readable sequence, and creates a new sequence.
*/
@Internal
public interface BufferBlocker {
/**
* Adds a buffer or event to the blocker.
*
* @param boe The buffer or event to be added into the blocker.
*/
void add(BufferOrEvent boe) throws IOException;
/**
* Starts a new sequence of buffers and event without reusing the same resources and
* returns the current sequence of buffers for reading.
*
* @return The readable sequence of buffers and events, or 'null', if nothing was added.
*/
BufferOrEventSequence rollOverWithoutReusingResources() throws IOException;
/**
* Starts a new sequence of buffers and event reusing the same resources and
* returns the current sequence of buffers for reading.
*
* @return The readable sequence of buffers and events, or 'null', if nothing was added.
*/
BufferOrEventSequence rollOverReusingResources() throws IOException;
/**
* Cleans up all the resources in the current sequence.
*/
void close() throws IOException;
/**
* Gets the number of bytes blocked in the current sequence.
*
* @return the number of bytes blocked in the current sequence.
*/
long getBytesBlocked();
}