| /* |
| * 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.hadoop.fs.adl; |
| |
| import com.microsoft.azure.datalake.store.ADLFileInputStream; |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.FSInputStream; |
| import org.apache.hadoop.fs.FileSystem.Statistics; |
| |
| import java.io.IOException; |
| |
| import static org.apache.hadoop.fs.adl.AdlConfKeys |
| .ADL_EXPERIMENT_POSITIONAL_READ_DEFAULT; |
| import static org.apache.hadoop.fs.adl.AdlConfKeys |
| .ADL_EXPERIMENT_POSITIONAL_READ_KEY; |
| import static org.apache.hadoop.fs.adl.AdlConfKeys |
| .DEFAULT_READ_AHEAD_BUFFER_SIZE; |
| import static org.apache.hadoop.fs.adl.AdlConfKeys.READ_AHEAD_BUFFER_SIZE_KEY; |
| |
| /** |
| * Wraps {@link ADLFileInputStream} implementation. |
| */ |
| @InterfaceAudience.Private |
| @InterfaceStability.Evolving |
| public final class AdlFsInputStream extends FSInputStream { |
| |
| private final ADLFileInputStream in; |
| private final Statistics stat; |
| private final boolean enablePositionalReadExperiment; |
| |
| public AdlFsInputStream(ADLFileInputStream inputStream, Statistics statistics, |
| Configuration conf) throws IOException { |
| this.in = inputStream; |
| this.in.setBufferSize(conf.getInt(READ_AHEAD_BUFFER_SIZE_KEY, |
| DEFAULT_READ_AHEAD_BUFFER_SIZE)); |
| enablePositionalReadExperiment = conf |
| .getBoolean(ADL_EXPERIMENT_POSITIONAL_READ_KEY, |
| ADL_EXPERIMENT_POSITIONAL_READ_DEFAULT); |
| stat = statistics; |
| } |
| |
| @Override |
| public synchronized void seek(long pos) throws IOException { |
| in.seek(pos); |
| } |
| |
| /** |
| * Return the current offset from the start of the file. |
| */ |
| @Override |
| public synchronized long getPos() throws IOException { |
| return in.getPos(); |
| } |
| |
| @Override |
| public boolean seekToNewSource(long l) throws IOException { |
| return false; |
| } |
| |
| @Override |
| public synchronized int read() throws IOException { |
| int ch = in.read(); |
| if (stat != null && ch != -1) { |
| stat.incrementBytesRead(1); |
| } |
| return ch; |
| } |
| |
| @Override |
| public int read(long position, byte[] buffer, int offset, int length) |
| throws IOException { |
| int numberOfByteRead = 0; |
| if (enablePositionalReadExperiment) { |
| numberOfByteRead = in.read(position, buffer, offset, length); |
| } else { |
| numberOfByteRead = super.read(position, buffer, offset, length); |
| } |
| |
| if (stat != null && numberOfByteRead > 0) { |
| stat.incrementBytesRead(numberOfByteRead); |
| } |
| return numberOfByteRead; |
| } |
| |
| @Override |
| public synchronized int read(byte[] buffer, int offset, int length) |
| throws IOException { |
| int numberOfByteRead = in.read(buffer, offset, length); |
| if (stat != null && numberOfByteRead > 0) { |
| stat.incrementBytesRead(numberOfByteRead); |
| } |
| return numberOfByteRead; |
| } |
| |
| /** |
| * This method returns the remaining bytes in the stream, rather than the |
| * expected Java |
| * interpretation of {@link java.io.InputStream#available()}, which expects |
| * the |
| * number of remaining |
| * bytes in the local buffer. Moreover, it caps the value returned to a |
| * maximum of Integer.MAX_VALUE. |
| * These changed behaviors are to ensure compatibility with the |
| * expectations of HBase WAL reader, |
| * which depends on available() returning the number of bytes in stream. |
| * |
| * Given all other FileSystems in the hadoop ecosystem (especially HDFS) do |
| * this, it is possible other |
| * apps other than HBase would also pick up expectation of this behavior |
| * based on HDFS implementation. |
| * Therefore keeping this quirky behavior here, to ensure compatibility. |
| * |
| * @return remaining bytes in the stream, with maximum of Integer.MAX_VALUE. |
| * @throws IOException If fails to get the position or file length from SDK. |
| */ |
| @Override |
| public synchronized int available() throws IOException { |
| return (int) Math.min(in.length() - in.getPos(), Integer.MAX_VALUE); |
| } |
| |
| @Override |
| public synchronized void close() throws IOException { |
| in.close(); |
| } |
| |
| @Override |
| public synchronized long skip(long pos) throws IOException { |
| return in.skip(pos); |
| } |
| |
| } |