kbendick commented on code in PR #968: URL: https://github.com/apache/parquet-mr/pull/968#discussion_r876172260
########## parquet-common/src/main/java/org/apache/parquet/bytes/AsyncMultiBufferInputStream.java: ########## @@ -0,0 +1,173 @@ +/* + * 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.parquet.bytes; + +import java.io.IOException; +import java.nio.ByteBuffer; +import java.util.List; +import java.util.concurrent.ExecutorService; +import java.util.concurrent.Future; +import java.util.concurrent.LinkedBlockingQueue; +import java.util.concurrent.TimeUnit; +import java.util.concurrent.atomic.LongAccumulator; +import java.util.concurrent.atomic.LongAdder; +import org.apache.parquet.io.SeekableInputStream; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +class AsyncMultiBufferInputStream extends MultiBufferInputStream { + + private static final Logger LOG = LoggerFactory.getLogger(AsyncMultiBufferInputStream.class); + + final SeekableInputStream fileInputStream; + int fetchIndex = 0; + int readIndex = 0; + ExecutorService threadPool; + LinkedBlockingQueue<Future<Void>> readFutures; + boolean closed = false; + Exception ioException; + + LongAdder totalTimeBlocked = new LongAdder(); + LongAdder totalCountBlocked = new LongAdder(); + LongAccumulator maxTimeBlocked = new LongAccumulator(Long::max, 0L); + + AsyncMultiBufferInputStream(ExecutorService threadPool, SeekableInputStream fileInputStream, + List<ByteBuffer> buffers) { + super(buffers); + this.fileInputStream = fileInputStream; + this.threadPool = threadPool; + readFutures = new LinkedBlockingQueue<>(buffers.size()); + if (LOG.isDebugEnabled()) { + LOG.debug("ASYNC: Begin read into buffers "); + for (ByteBuffer buf : buffers) { + LOG.debug("ASYNC: buffer {} ", buf); + } + } + fetchAll(); + } + + private void checkState() { + if (closed) { + throw new RuntimeException("Stream is closed"); + } + synchronized (this) { + if (ioException != null) { + throw new RuntimeException(ioException); + } + } + } + + private void fetchAll() { + checkState(); + submitReadTask(0); + } + + private void submitReadTask(int bufferNo) { + ByteBuffer buffer = buffers.get(bufferNo); + try { + readFutures.put(threadPool.submit(() -> { + readOneBuffer(buffer); + if (bufferNo < buffers.size() - 1) { + submitReadTask(bufferNo + 1); + } + return null; + }) + ); + } catch (InterruptedException e) { + Thread.currentThread().interrupt(); + throw new RuntimeException(e); + } + } + + private void readOneBuffer(ByteBuffer buffer) { + long startTime = System.nanoTime(); + try { + fileInputStream.readFully(buffer); + buffer.flip(); + long readCompleted = System.nanoTime(); + long timeSpent = readCompleted - startTime; + LOG.debug("ASYNC Stream: READ - {}", timeSpent / 1000.0); + long putStart = System.nanoTime(); + long putCompleted = System.nanoTime(); + LOG.debug("ASYNC Stream: FS READ (output) BLOCKED - {}", + (putCompleted - putStart) / 1000.0); + fetchIndex++; + } catch (IOException e) { + // Save the exception so that the calling thread can check if something went wrong. + // checkState will throw an exception if the read task has failed. + synchronized(this) { + ioException = e; + } + throw new RuntimeException(e); + } + } + + @Override + public boolean nextBuffer() { + checkState(); + // hack: parent constructor can call this method before this class is fully initialized. + // Just return without doing anything. + if (readFutures == null) { + return false; + } Review Comment: Because `checkState` has synchronization, would it be safe to move the `checkState` before this somehow or add some kind of less expensive boolean check that we can set to `true` immediately after the `super()` call? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: dev-unsubscr...@parquet.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
