| /* |
| * 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.hadoop.util; |
| |
| import org.apache.hadoop.fs.ByteBufferReadable; |
| import org.apache.hadoop.fs.FSDataInputStream; |
| import org.apache.hadoop.fs.FSDataOutputStream; |
| import org.apache.parquet.io.PositionOutputStream; |
| import org.apache.parquet.io.SeekableInputStream; |
| import org.apache.parquet.util.DynMethods; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import java.io.InputStream; |
| import java.util.Objects; |
| |
| /** |
| * Convenience methods to get Parquet abstractions for Hadoop data streams. |
| */ |
| public class HadoopStreams { |
| |
| private static final Logger LOG = LoggerFactory.getLogger(HadoopStreams.class); |
| |
| private static final DynMethods.UnboundMethod hasCapabilitiesMethod = |
| new DynMethods |
| .Builder("hasCapabilities") |
| .impl(FSDataInputStream.class, "hasCapabilities", String.class) |
| .orNoop() |
| .build(); |
| |
| /** |
| * Wraps a {@link FSDataInputStream} in a {@link SeekableInputStream} |
| * implementation for Parquet readers. |
| * |
| * @param stream a Hadoop FSDataInputStream |
| * @return a SeekableInputStream |
| */ |
| public static SeekableInputStream wrap(FSDataInputStream stream) { |
| Objects.requireNonNull(stream, "Cannot wrap a null input stream"); |
| |
| // Try to check using hasCapabilities(str) |
| Boolean hasCapabilitiesResult = isWrappedStreamByteBufferReadable(stream); |
| |
| // If it is null, then fall back to the old method |
| if (hasCapabilitiesResult != null) { |
| if (hasCapabilitiesResult) { |
| return new H2SeekableInputStream(stream); |
| } else { |
| return new H1SeekableInputStream(stream); |
| } |
| } |
| |
| return unwrapByteBufferReadableLegacy(stream); |
| } |
| |
| /** |
| * Is the inner stream byte buffer readable? |
| * The test is 'the stream is not FSDataInputStream |
| * and implements ByteBufferReadable' |
| * |
| * This logic is only used for Hadoop <2.9.x, and <3.x.x |
| * |
| * @param stream stream to probe |
| * @return A H2SeekableInputStream to access, or H1SeekableInputStream if the stream is not seekable |
| */ |
| private static SeekableInputStream unwrapByteBufferReadableLegacy(FSDataInputStream stream) { |
| InputStream wrapped = stream.getWrappedStream(); |
| if (wrapped instanceof FSDataInputStream) { |
| LOG.debug("Checking on wrapped stream {} of {} whether is ByteBufferReadable", wrapped, stream); |
| return unwrapByteBufferReadableLegacy(((FSDataInputStream) wrapped)); |
| } |
| if (stream.getWrappedStream() instanceof ByteBufferReadable) { |
| return new H2SeekableInputStream(stream); |
| } else { |
| return new H1SeekableInputStream(stream); |
| } |
| } |
| |
| /** |
| * Is the inner stream byte buffer readable? |
| * The test is 'the stream is not FSDataInputStream |
| * and implements ByteBufferReadable' |
| * |
| * That is: all streams which implement ByteBufferReadable |
| * other than FSDataInputStream successfully support read(ByteBuffer). |
| * This is true for all filesystem clients the hadoop codebase. |
| * |
| * In hadoop 3.3.0+, the StreamCapabilities probe can be used to |
| * check this: only those streams which provide the read(ByteBuffer) |
| * semantics MAY return true for the probe "in:readbytebuffer"; |
| * FSDataInputStream will pass the probe down to the underlying stream. |
| * |
| * @param stream stream to probe |
| * @return true if it is safe to a H2SeekableInputStream to access |
| * the data, null when it cannot be determined because of missing hasCapabilities |
| */ |
| private static Boolean isWrappedStreamByteBufferReadable(FSDataInputStream stream) { |
| if (hasCapabilitiesMethod.isNoop()) { |
| // When the method is not available, just return a null |
| return null; |
| } |
| |
| boolean isByteBufferReadable = hasCapabilitiesMethod.invoke(stream, "in:readbytebuffer"); |
| |
| if (isByteBufferReadable) { |
| // stream is issuing the guarantee that it implements the |
| // API. Holds for all implementations in hadoop-* |
| // since Hadoop 3.3.0 (HDFS-14111). |
| return true; |
| } |
| InputStream wrapped = stream.getWrappedStream(); |
| if (wrapped instanceof FSDataInputStream) { |
| LOG.debug("Checking on wrapped stream {} of {} whether is ByteBufferReadable", wrapped, stream); |
| return isWrappedStreamByteBufferReadable(((FSDataInputStream) wrapped)); |
| } |
| return wrapped instanceof ByteBufferReadable; |
| } |
| |
| |
| /** |
| * Wraps a {@link FSDataOutputStream} in a {@link PositionOutputStream} |
| * implementation for Parquet writers. |
| * |
| * @param stream a Hadoop FSDataOutputStream |
| * @return a SeekableOutputStream |
| */ |
| public static PositionOutputStream wrap(FSDataOutputStream stream) { |
| Objects.requireNonNull(stream, "Cannot wrap a null output stream"); |
| return new HadoopPositionOutputStream(stream); |
| } |
| } |