org.apache.flink.runtime.io.network.partition.external.writer.AsynchronousPartitionedStreamFileReaderDelegate 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.io.network.partition.external.writer;
import org.apache.flink.core.memory.MemorySegment;
import org.apache.flink.runtime.io.disk.iomanager.BufferFileReader;
import org.apache.flink.runtime.io.disk.iomanager.FileIOChannel;
import org.apache.flink.runtime.io.disk.iomanager.IOManager;
import org.apache.flink.runtime.io.disk.iomanager.RequestDoneCallback;
import org.apache.flink.runtime.io.network.buffer.Buffer;
import org.apache.flink.runtime.io.network.buffer.BufferRecycler;
import org.apache.flink.runtime.io.network.buffer.NetworkBuffer;
import org.apache.flink.runtime.io.network.partition.external.PartitionIndex;
import java.io.IOException;
import java.util.ArrayDeque;
import java.util.List;
import java.util.Queue;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;
/**
* An utility class helps read buffers with limited free memory segments from
* a buffer file.
*
* It first sends requests as long as there are available buffers. Then after a
* buffer is returned, it will then send a new request with the recycled buffers.
*/
public class AsynchronousPartitionedStreamFileReaderDelegate implements RequestDoneCallback, BufferRecycler {
private final BufferFileReader reader;
private final Queue freeSegments;
private final LinkedBlockingQueue retBuffers = new LinkedBlockingQueue<>();
private final List partitionIndices;
private int nextPartitionIdx;
private long nextOffset;
private final AtomicReference cause = new AtomicReference<>(null);
public AsynchronousPartitionedStreamFileReaderDelegate(IOManager ioManager, FileIOChannel.ID channel,
List segments,
List partitionIndices)throws IOException {
this.reader = ioManager.createStreamFileReader(channel, this);
this.freeSegments = new ArrayDeque<>(segments);
this.partitionIndices = partitionIndices;
MemorySegment segment;
while ((segment = freeSegments.poll()) != null) {
sendRequestIfFeasible(segment);
}
}
BufferFileReader getReader() {
return reader;
}
Buffer getNextBufferBlocking() throws InterruptedException, IOException {
Buffer buffer;
do {
if (cause.get() != null) {
throw cause.get();
}
buffer = retBuffers.poll(500, TimeUnit.MILLISECONDS);
} while (buffer == null);
return buffer;
}
private void sendRequestIfFeasible(MemorySegment memorySegment) throws IOException {
long nextReadLength = 0;
while (nextPartitionIdx < partitionIndices.size()) {
PartitionIndex partitionIndex = partitionIndices.get(nextPartitionIdx);
long partitionEndOffset = partitionIndex.getStartOffset() + partitionIndex.getLength();
assert partitionEndOffset >= nextOffset;
if (partitionEndOffset > nextOffset) {
nextReadLength = Math.min(partitionEndOffset - nextOffset, memorySegment.size());
break;
}
nextPartitionIdx++;
}
if (nextReadLength > 0) {
Buffer buffer = new NetworkBuffer(memorySegment, this);
reader.readInto(buffer, nextReadLength);
nextOffset += nextReadLength;
}
}
@Override
public void requestSuccessful(Buffer buffer) {
retBuffers.add(buffer);
}
@Override
public void requestFailed(Buffer buffer, IOException e) {
cause.compareAndSet(null, e);
throw new RuntimeException(e);
}
@Override
public void recycle(MemorySegment memorySegment) {
try {
sendRequestIfFeasible(memorySegment);
} catch (IOException e) {
cause.compareAndSet(null, e);
throw new RuntimeException(e);
}
}
void close() throws IOException {
this.reader.close();
this.freeSegments.clear();
}
}