ggershinsky commented on code in PR #968: URL: https://github.com/apache/parquet-mr/pull/968#discussion_r903399997
########## parquet-common/src/main/java/org/apache/parquet/bytes/AsyncMultiBufferInputStream.java: ########## @@ -0,0 +1,158 @@ +/* + * 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); + + private int fetchIndex = 0; + private final SeekableInputStream fileInputStream; + private int readIndex = 0; + private ExecutorService threadPool; + private LinkedBlockingQueue<Future<Void>> readFutures; + private boolean closed = false; + + private LongAdder totalTimeBlocked = new LongAdder(); + private LongAdder totalCountBlocked = new LongAdder(); + private 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"); + } + } + + 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); + fetchIndex++; + } catch (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; + } + if (readIndex < buffers.size()) { + long start = System.nanoTime(); + try { + LOG.debug("ASYNC (next): Getting next buffer"); + Future<Void> future = readFutures.take(); + future.get(); + long timeSpent = System.nanoTime() - start; + totalCountBlocked.add(1); + totalTimeBlocked.add(timeSpent); + maxTimeBlocked.accumulate(timeSpent); + LOG.debug("ASYNC (next): {}: Time blocked for read {} ns", this, timeSpent); Review Comment: should `if (LOG.isDebugEnabled()) {` be added here and in 118? This check is performed in the constructor (line 58); `nextBuffer()` is called with higher(/same) frequency. -- 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
