| /** |
| * 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.hdfs.client; |
| |
| import java.io.InputStream; |
| import java.io.IOException; |
| import java.util.List; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.fs.FSDataInputStream; |
| import org.apache.hadoop.crypto.CryptoInputStream; |
| import org.apache.hadoop.hdfs.DFSInputStream; |
| import org.apache.hadoop.hdfs.ReadStatistics; |
| import org.apache.hadoop.hdfs.protocol.DatanodeInfo; |
| import org.apache.hadoop.hdfs.protocol.ExtendedBlock; |
| import org.apache.hadoop.hdfs.protocol.LocatedBlock; |
| |
| import com.google.common.base.Preconditions; |
| |
| /** |
| * The Hdfs implementation of {@link FSDataInputStream}. |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Evolving |
| public class HdfsDataInputStream extends FSDataInputStream { |
| public HdfsDataInputStream(DFSInputStream in) { |
| super(in); |
| } |
| |
| public HdfsDataInputStream(CryptoInputStream in) { |
| super(in); |
| Preconditions.checkArgument(in.getWrappedStream() instanceof DFSInputStream, |
| "CryptoInputStream should wrap a DFSInputStream"); |
| } |
| |
| private DFSInputStream getDFSInputStream() { |
| if (in instanceof CryptoInputStream) { |
| return (DFSInputStream) ((CryptoInputStream) in).getWrappedStream(); |
| } |
| return (DFSInputStream) in; |
| } |
| |
| /** |
| * Get a reference to the wrapped output stream. We always want to return the |
| * actual underlying InputStream, even when we're using a CryptoStream. e.g. |
| * in the delegated methods below. |
| * |
| * @return the underlying output stream |
| */ |
| public InputStream getWrappedStream() { |
| return in; |
| } |
| |
| /** |
| * Get the datanode from which the stream is currently reading. |
| */ |
| public DatanodeInfo getCurrentDatanode() { |
| return getDFSInputStream().getCurrentDatanode(); |
| } |
| |
| /** |
| * Get the block containing the target position. |
| */ |
| public ExtendedBlock getCurrentBlock() { |
| return getDFSInputStream().getCurrentBlock(); |
| } |
| |
| /** |
| * Get the collection of blocks that has already been located. |
| */ |
| public List<LocatedBlock> getAllBlocks() throws IOException { |
| return getDFSInputStream().getAllBlocks(); |
| } |
| |
| /** |
| * Get the visible length of the file. It will include the length of the last |
| * block even if that is in UnderConstruction state. |
| * |
| * @return The visible length of the file. |
| */ |
| public long getVisibleLength() { |
| return getDFSInputStream().getFileLength(); |
| } |
| |
| /** |
| * Get statistics about the reads which this DFSInputStream has done. |
| * Note that because HdfsDataInputStream is buffered, these stats may |
| * be higher than you would expect just by adding up the number of |
| * bytes read through HdfsDataInputStream. |
| */ |
| public ReadStatistics getReadStatistics() { |
| return getDFSInputStream().getReadStatistics(); |
| } |
| |
| public void clearReadStatistics() { |
| getDFSInputStream().clearReadStatistics(); |
| } |
| } |