org.apache.flink.runtime.operators.sort.SortedDataFileMerger Maven / Gradle / Ivy

/*
 * 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.runtime.operators.sort;

import org.apache.flink.core.memory.MemorySegment;
import org.apache.flink.util.MutableObjectIterator;

import java.io.IOException;
import java.util.List;
import java.util.concurrent.atomic.AtomicBoolean;

/**
 * Mering policy for a list of sorted data files.
 */
public interface SortedDataFileMerger {

	/**
	 * Gets the merging iterator to read data in-order for a list of sorted data files and an optional large records
	 * iterator.
	 *
	 * @param files the files based to create the merging iterator
	 * @param mergeReadMemory the memory used to read files during merging
	 * @param largeRecords the iterator of large records
	 * @param channelDeleteRegistry the registry to manage files to be close and delete
	 * @throws IOException if file read or write fails
	 */
	MutableObjectIterator getMergingIterator(List> files,
												List mergeReadMemory,
												MutableObjectIterator largeRecords,
												ChannelDeleteRegistry channelDeleteRegistry) throws IOException;

	/**
	 * Notifies that a new sorted data file can get merged, the merge policy will decide
	 * whether merging should be triggered.
	 *
	 * @param writeMemory the memory used to write files during merging
	 * @param mergeReadMemory the memory used to read files during merging
	 * @param channelDeleteRegistry the registry to manage files to be close and delete
	 * @param aliveFlag flags indicating whether the merge should continue
	 * @throws IOException if file read or write fails
	 */
	void notifyNewSortedDataFile(SortedDataFile sortedDataFile,
									List writeMemory,
									List mergeReadMemory,
									ChannelDeleteRegistry channelDeleteRegistry,
									AtomicBoolean aliveFlag) throws IOException;

	/**
	 *
	 * @param writeMemory the memory used to write files during merging
	 * @param mergeReadMemory the memory used to read files during merging
	 * @param channelDeleteRegistry the registry to manage files to be close and delete
	 * @param aliveFlag flags indicating whether the merge should continue
	 * @return the final merged file list
	 * @throws IOException if file read or write fails
	 */
	List> finishMerging(List writeMemory,
										  List mergeReadMemory,
										  ChannelDeleteRegistry channelDeleteRegistry,
										  AtomicBoolean aliveFlag) throws IOException;
}