HDFS-8905. Refactor DFSInputStream#ReaderStrategy. Contributed by Kai Zheng and Sammi Chen

This commit is contained in:
Kai Zheng 2016-08-24 21:57:23 +08:00
parent ec252ce0fc
commit 793447f799
7 changed files with 374 additions and 228 deletions

View File

@ -71,6 +71,7 @@ import org.apache.hadoop.hdfs.security.token.block.InvalidBlockTokenException;
import org.apache.hadoop.hdfs.server.datanode.CachingStrategy;
import org.apache.hadoop.hdfs.server.datanode.ReplicaNotFoundException;
import org.apache.hadoop.hdfs.shortcircuit.ClientMmap;
import org.apache.hadoop.hdfs.util.IOUtilsClient;
import org.apache.hadoop.io.ByteBufferPool;
import org.apache.hadoop.ipc.RPC;
import org.apache.hadoop.ipc.RemoteException;
@ -145,94 +146,6 @@ public class DFSInputStream extends FSInputStream
return extendedReadBuffers;
}
public static class ReadStatistics {
public ReadStatistics() {
clear();
}
public ReadStatistics(ReadStatistics rhs) {
this.totalBytesRead = rhs.getTotalBytesRead();
this.totalLocalBytesRead = rhs.getTotalLocalBytesRead();
this.totalShortCircuitBytesRead = rhs.getTotalShortCircuitBytesRead();
this.totalZeroCopyBytesRead = rhs.getTotalZeroCopyBytesRead();
}
/**
* @return The total bytes read. This will always be at least as
* high as the other numbers, since it includes all of them.
*/
public long getTotalBytesRead() {
return totalBytesRead;
}
/**
* @return The total local bytes read. This will always be at least
* as high as totalShortCircuitBytesRead, since all short-circuit
* reads are also local.
*/
public long getTotalLocalBytesRead() {
return totalLocalBytesRead;
}
/**
* @return The total short-circuit local bytes read.
*/
public long getTotalShortCircuitBytesRead() {
return totalShortCircuitBytesRead;
}
/**
* @return The total number of zero-copy bytes read.
*/
public long getTotalZeroCopyBytesRead() {
return totalZeroCopyBytesRead;
}
/**
* @return The total number of bytes read which were not local.
*/
public long getRemoteBytesRead() {
return totalBytesRead - totalLocalBytesRead;
}
void addRemoteBytes(long amt) {
this.totalBytesRead += amt;
}
void addLocalBytes(long amt) {
this.totalBytesRead += amt;
this.totalLocalBytesRead += amt;
}
void addShortCircuitBytes(long amt) {
this.totalBytesRead += amt;
this.totalLocalBytesRead += amt;
this.totalShortCircuitBytesRead += amt;
}
void addZeroCopyBytes(long amt) {
this.totalBytesRead += amt;
this.totalLocalBytesRead += amt;
this.totalShortCircuitBytesRead += amt;
this.totalZeroCopyBytesRead += amt;
}
void clear() {
this.totalBytesRead = 0;
this.totalLocalBytesRead = 0;
this.totalShortCircuitBytesRead = 0;
this.totalZeroCopyBytesRead = 0;
}
private long totalBytesRead;
private long totalLocalBytesRead;
private long totalShortCircuitBytesRead;
private long totalZeroCopyBytesRead;
}
/**
* This variable tracks the number of failures since the start of the
* most recent user-facing operation. That is to say, it should be reset
@ -767,116 +680,11 @@ public class DFSInputStream extends FSInputStream
return ( ret <= 0 ) ? -1 : (oneByteBuf[0] & 0xff);
}
/**
* Wraps different possible read implementations so that readBuffer can be
* strategy-agnostic.
*/
interface ReaderStrategy {
int doRead(BlockReader blockReader, int off, int len)
throws IOException;
/**
* Copy data from the src ByteBuffer into the read buffer.
* @param src The src buffer where the data is copied from
* @param offset Useful only when the ReadStrategy is based on a byte array.
* Indicate the offset of the byte array for copy.
* @param length Useful only when the ReadStrategy is based on a byte array.
* Indicate the length of the data to copy.
*/
int copyFrom(ByteBuffer src, int offset, int length);
}
protected void updateReadStatistics(ReadStatistics readStatistics,
int nRead, BlockReader blockReader) {
if (nRead <= 0) return;
synchronized(infoLock) {
if (blockReader.isShortCircuit()) {
readStatistics.addShortCircuitBytes(nRead);
} else if (blockReader.getNetworkDistance() == 0) {
readStatistics.addLocalBytes(nRead);
} else {
readStatistics.addRemoteBytes(nRead);
}
}
}
/**
* Used to read bytes into a byte[]
*/
private class ByteArrayStrategy implements ReaderStrategy {
final byte[] buf;
public ByteArrayStrategy(byte[] buf) {
this.buf = buf;
}
@Override
public int doRead(BlockReader blockReader, int off, int len)
throws IOException {
int nRead = blockReader.read(buf, off, len);
updateReadStatistics(readStatistics, nRead, blockReader);
dfsClient.updateFileSystemReadStats(blockReader.getNetworkDistance(),
nRead);
return nRead;
}
@Override
public int copyFrom(ByteBuffer src, int offset, int length) {
ByteBuffer writeSlice = src.duplicate();
writeSlice.get(buf, offset, length);
return length;
}
}
/**
* Used to read bytes into a user-supplied ByteBuffer
*/
protected class ByteBufferStrategy implements ReaderStrategy {
final ByteBuffer buf;
ByteBufferStrategy(ByteBuffer buf) {
this.buf = buf;
}
@Override
public int doRead(BlockReader blockReader, int off, int len)
throws IOException {
int oldpos = buf.position();
int oldlimit = buf.limit();
boolean success = false;
try {
int ret = blockReader.read(buf);
success = true;
updateReadStatistics(readStatistics, ret, blockReader);
dfsClient.updateFileSystemReadStats(blockReader.getNetworkDistance(),
ret);
if (ret == 0) {
DFSClient.LOG.warn("zero");
}
return ret;
} finally {
if (!success) {
// Reset to original state so that retries work correctly.
buf.position(oldpos);
buf.limit(oldlimit);
}
}
}
@Override
public int copyFrom(ByteBuffer src, int offset, int length) {
ByteBuffer writeSlice = src.duplicate();
int remaining = Math.min(buf.remaining(), writeSlice.remaining());
writeSlice.limit(writeSlice.position() + remaining);
buf.put(writeSlice);
return remaining;
}
}
/* This is a used by regular read() and handles ChecksumExceptions.
* name readBuffer() is chosen to imply similarity to readBuffer() in
* ChecksumFileSystem
*/
private synchronized int readBuffer(ReaderStrategy reader, int off, int len,
private synchronized int readBuffer(ReaderStrategy reader, int len,
CorruptedBlocks corruptedBlocks)
throws IOException {
IOException ioe;
@ -892,7 +700,7 @@ public class DFSInputStream extends FSInputStream
while (true) {
// retry as many times as seekToNewSource allows.
try {
return reader.doRead(blockReader, off, len);
return reader.readFromBlock(blockReader, len);
} catch ( ChecksumException ce ) {
DFSClient.LOG.warn("Found Checksum error for "
+ getCurrentBlock() + " from " + currentNode
@ -927,13 +735,14 @@ public class DFSInputStream extends FSInputStream
}
}
protected synchronized int readWithStrategy(ReaderStrategy strategy, int off,
int len) throws IOException {
protected synchronized int readWithStrategy(ReaderStrategy strategy)
throws IOException {
dfsClient.checkOpen();
if (closed.get()) {
throw new IOException("Stream closed");
}
int len = strategy.getTargetLength();
CorruptedBlocks corruptedBlocks = new CorruptedBlocks();
failures = 0;
if (pos < getFileLength()) {
@ -952,7 +761,7 @@ public class DFSInputStream extends FSInputStream
locatedBlocks.getFileLength() - pos);
}
}
int result = readBuffer(strategy, off, realLen, corruptedBlocks);
int result = readBuffer(strategy, realLen, corruptedBlocks);
if (result >= 0) {
pos += result;
@ -994,11 +803,12 @@ public class DFSInputStream extends FSInputStream
if (len == 0) {
return 0;
}
ReaderStrategy byteArrayReader = new ByteArrayStrategy(buf);
ReaderStrategy byteArrayReader =
new ByteArrayStrategy(buf, off, len, readStatistics, dfsClient);
try (TraceScope scope =
dfsClient.newReaderTraceScope("DFSInputStream#byteArrayRead",
src, getPos(), len)) {
int retLen = readWithStrategy(byteArrayReader, off, len);
int retLen = readWithStrategy(byteArrayReader);
if (retLen < len) {
dfsClient.addRetLenToReaderScope(scope, retLen);
}
@ -1008,12 +818,13 @@ public class DFSInputStream extends FSInputStream
@Override
public synchronized int read(final ByteBuffer buf) throws IOException {
ReaderStrategy byteBufferReader = new ByteBufferStrategy(buf);
ReaderStrategy byteBufferReader =
new ByteBufferStrategy(buf, readStatistics, dfsClient);
int reqLen = buf.remaining();
try (TraceScope scope =
dfsClient.newReaderTraceScope("DFSInputStream#byteBufferRead",
src, getPos(), reqLen)){
int retLen = readWithStrategy(byteBufferReader, 0, reqLen);
int retLen = readWithStrategy(byteBufferReader);
if (retLen < reqLen) {
dfsClient.addRetLenToReaderScope(scope, retLen);
}
@ -1221,7 +1032,7 @@ public class DFSInputStream extends FSInputStream
reader = getBlockReader(block, startInBlk, len, datanode.addr,
datanode.storageType, datanode.info);
int nread = reader.readAll(buf, offset, len);
updateReadStatistics(readStatistics, nread, reader);
IOUtilsClient.updateReadStatistics(readStatistics, nread, reader);
dfsClient.updateFileSystemReadStats(
reader.getNetworkDistance(), nread);
if (nread != len) {
@ -1721,19 +1532,15 @@ public class DFSInputStream extends FSInputStream
* Get statistics about the reads which this DFSInputStream has done.
*/
public ReadStatistics getReadStatistics() {
synchronized(infoLock) {
return new ReadStatistics(readStatistics);
}
}
/**
* Clear statistics about the reads which this DFSInputStream has done.
*/
public void clearReadStatistics() {
synchronized(infoLock) {
readStatistics.clear();
}
}
public FileEncryptionInfo getFileEncryptionInfo() {
synchronized(infoLock) {
@ -1759,7 +1566,8 @@ public class DFSInputStream extends FSInputStream
throws IOException {
synchronized (infoLock) {
this.cachingStrategy =
new CachingStrategy.Builder(this.cachingStrategy).setReadahead(readahead).build();
new CachingStrategy.Builder(this.cachingStrategy).
setReadahead(readahead).build();
}
closeCurrentBlockReaders();
}
@ -1769,7 +1577,8 @@ public class DFSInputStream extends FSInputStream
throws IOException {
synchronized (infoLock) {
this.cachingStrategy =
new CachingStrategy.Builder(this.cachingStrategy).setDropBehind(dropBehind).build();
new CachingStrategy.Builder(this.cachingStrategy).
setDropBehind(dropBehind).build();
}
closeCurrentBlockReaders();
}
@ -1883,9 +1692,7 @@ public class DFSInputStream extends FSInputStream
buffer.position((int)blockPos);
buffer.limit((int)(blockPos + length));
getExtendedReadBuffers().put(buffer, clientMmap);
synchronized (infoLock) {
readStatistics.addZeroCopyBytes(length);
}
DFSClient.LOG.debug("readZeroCopy read {} bytes from offset {} via the "
+ "zero-copy read path. blockEnd = {}", length, curPos, blockEnd);
success = true;

View File

@ -359,11 +359,11 @@ public class DFSStripedInputStream extends DFSInputStream {
ExtendedBlock currentBlock,
CorruptedBlocks corruptedBlocks)
throws IOException {
final int targetLength = strategy.buf.remaining();
final int targetLength = strategy.getTargetLength();
int length = 0;
try {
while (length < targetLength) {
int ret = strategy.doRead(blockReader, 0, 0);
int ret = strategy.readFromBlock(blockReader);
if (ret < 0) {
throw new IOException("Unexpected EOS from the reader");
}
@ -425,13 +425,14 @@ public class DFSStripedInputStream extends DFSInputStream {
}
@Override
protected synchronized int readWithStrategy(ReaderStrategy strategy,
int off, int len) throws IOException {
protected synchronized int readWithStrategy(ReaderStrategy strategy)
throws IOException {
dfsClient.checkOpen();
if (closed.get()) {
throw new IOException("Stream closed");
}
int len = strategy.getTargetLength();
CorruptedBlocks corruptedBlocks = new CorruptedBlocks();
if (pos < getFileLength()) {
try {
@ -452,7 +453,7 @@ public class DFSStripedInputStream extends DFSInputStream {
if (!curStripeRange.include(getOffsetInBlockGroup())) {
readOneStripe(corruptedBlocks);
}
int ret = copyToTargetBuf(strategy, off + result, realLen - result);
int ret = copyToTargetBuf(strategy, realLen - result);
result += ret;
pos += ret;
}
@ -470,16 +471,14 @@ public class DFSStripedInputStream extends DFSInputStream {
/**
* Copy the data from {@link #curStripeBuf} into the given buffer
* @param strategy the ReaderStrategy containing the given buffer
* @param offset the offset of the given buffer. Used only when strategy is
* a ByteArrayStrategy
* @param length target length
* @return number of bytes copied
*/
private int copyToTargetBuf(ReaderStrategy strategy, int offset, int length) {
private int copyToTargetBuf(ReaderStrategy strategy, int length) {
final long offsetInBlk = getOffsetInBlockGroup();
int bufOffset = getStripedBufOffset(offsetInBlk);
curStripeBuf.position(bufOffset);
return strategy.copyFrom(curStripeBuf, offset,
return strategy.readFromBuffer(curStripeBuf,
Math.min(length, curStripeBuf.remaining()));
}
@ -700,7 +699,8 @@ public class DFSStripedInputStream extends DFSInputStream {
private ByteBufferStrategy[] getReadStrategies(StripingChunk chunk) {
if (chunk.byteBuffer != null) {
ByteBufferStrategy strategy = new ByteBufferStrategy(chunk.byteBuffer);
ByteBufferStrategy strategy =
new ByteBufferStrategy(chunk.byteBuffer, readStatistics, dfsClient);
return new ByteBufferStrategy[]{strategy};
} else {
ByteBufferStrategy[] strategies =
@ -708,7 +708,8 @@ public class DFSStripedInputStream extends DFSInputStream {
for (int i = 0; i < strategies.length; i++) {
ByteBuffer buffer = ByteBuffer.wrap(chunk.byteArray.buf(),
chunk.byteArray.getOffsets()[i], chunk.byteArray.getLengths()[i]);
strategies[i] = new ByteBufferStrategy(buffer);
strategies[i] =
new ByteBufferStrategy(buffer, readStatistics, dfsClient);
}
return strategies;
}

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@ -0,0 +1,106 @@
/**
* 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;
/**
* A utility class that maintains statistics for reading.
*/
public class ReadStatistics {
private long totalBytesRead;
private long totalLocalBytesRead;
private long totalShortCircuitBytesRead;
private long totalZeroCopyBytesRead;
public ReadStatistics() {
clear();
}
public ReadStatistics(ReadStatistics rhs) {
this.totalBytesRead = rhs.getTotalBytesRead();
this.totalLocalBytesRead = rhs.getTotalLocalBytesRead();
this.totalShortCircuitBytesRead = rhs.getTotalShortCircuitBytesRead();
this.totalZeroCopyBytesRead = rhs.getTotalZeroCopyBytesRead();
}
/**
* @return The total bytes read. This will always be at least as
* high as the other numbers, since it includes all of them.
*/
public synchronized long getTotalBytesRead() {
return totalBytesRead;
}
/**
* @return The total local bytes read. This will always be at least
* as high as totalShortCircuitBytesRead, since all short-circuit
* reads are also local.
*/
public synchronized long getTotalLocalBytesRead() {
return totalLocalBytesRead;
}
/**
* @return The total short-circuit local bytes read.
*/
public synchronized long getTotalShortCircuitBytesRead() {
return totalShortCircuitBytesRead;
}
/**
* @return The total number of zero-copy bytes read.
*/
public synchronized long getTotalZeroCopyBytesRead() {
return totalZeroCopyBytesRead;
}
/**
* @return The total number of bytes read which were not local.
*/
public synchronized long getRemoteBytesRead() {
return totalBytesRead - totalLocalBytesRead;
}
public synchronized void addRemoteBytes(long amt) {
this.totalBytesRead += amt;
}
public synchronized void addLocalBytes(long amt) {
this.totalBytesRead += amt;
this.totalLocalBytesRead += amt;
}
public synchronized void addShortCircuitBytes(long amt) {
this.totalBytesRead += amt;
this.totalLocalBytesRead += amt;
this.totalShortCircuitBytesRead += amt;
}
public synchronized void addZeroCopyBytes(long amt) {
this.totalBytesRead += amt;
this.totalLocalBytesRead += amt;
this.totalShortCircuitBytesRead += amt;
this.totalZeroCopyBytesRead += amt;
}
public synchronized void clear() {
this.totalBytesRead = 0;
this.totalLocalBytesRead = 0;
this.totalShortCircuitBytesRead = 0;
this.totalZeroCopyBytesRead = 0;
}
}

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@ -0,0 +1,215 @@
/**
* 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;
import java.io.IOException;
import java.nio.ByteBuffer;
import static org.apache.hadoop.hdfs.util.IOUtilsClient.updateReadStatistics;
/**
* Wraps different possible read implementations so that callers can be
* strategy-agnostic.
*/
interface ReaderStrategy {
/**
* Read from a block using the blockReader.
* @param blockReader
* @return number of bytes read
* @throws IOException
*/
int readFromBlock(BlockReader blockReader) throws IOException;
/**
* Read from a block using the blockReader with desired length to read.
* @param blockReader
* @param length number of bytes desired to read, not ensured
* @return number of bytes read
* @throws IOException
*/
int readFromBlock(BlockReader blockReader, int length) throws IOException;
/**
* Read or copy from a src buffer.
* @param src
* @return number of bytes copied
* Note: the position of the src buffer is not changed after the call
*/
int readFromBuffer(ByteBuffer src);
/**
* Read or copy length of data bytes from a src buffer with desired length.
* @param src
* @return number of bytes copied
* Note: the position of the src buffer is not changed after the call
*/
int readFromBuffer(ByteBuffer src, int length);
/**
* @return the target read buffer that reads data into.
*/
ByteBuffer getReadBuffer();
/**
* @return the target length to read.
*/
int getTargetLength();
}
/**
* Used to read bytes into a byte array buffer. Note it's not thread-safe
* and the behavior is not defined if concurrently operated.
*/
class ByteArrayStrategy implements ReaderStrategy {
private final DFSClient dfsClient;
private final ReadStatistics readStatistics;
private final byte[] readBuf;
private int offset;
private final int targetLength;
/**
* The constructor.
* @param readBuf target buffer to read into
* @param offset offset into the buffer
* @param targetLength target length of data
* @param readStatistics statistics counter
*/
public ByteArrayStrategy(byte[] readBuf, int offset, int targetLength,
ReadStatistics readStatistics,
DFSClient dfsClient) {
this.readBuf = readBuf;
this.offset = offset;
this.targetLength = targetLength;
this.readStatistics = readStatistics;
this.dfsClient = dfsClient;
}
@Override
public ByteBuffer getReadBuffer() {
return ByteBuffer.wrap(readBuf, offset, targetLength);
}
@Override
public int getTargetLength() {
return targetLength;
}
@Override
public int readFromBlock(BlockReader blockReader) throws IOException {
return readFromBlock(blockReader, targetLength);
}
@Override
public int readFromBlock(BlockReader blockReader,
int length) throws IOException {
int nRead = blockReader.read(readBuf, offset, length);
if (nRead > 0) {
updateReadStatistics(readStatistics, nRead, blockReader);
dfsClient.updateFileSystemReadStats(blockReader.getNetworkDistance(),
nRead);
offset += nRead;
}
return nRead;
}
@Override
public int readFromBuffer(ByteBuffer src) {
return readFromBuffer(src, src.remaining());
}
@Override
public int readFromBuffer(ByteBuffer src, int length) {
ByteBuffer dup = src.duplicate();
dup.get(readBuf, offset, length);
offset += length;
return length;
}
}
/**
* Used to read bytes into a user-supplied ByteBuffer. Note it's not thread-safe
* and the behavior is not defined if concurrently operated. When read operation
* is performed, the position of the underlying byte buffer will move forward as
* stated in ByteBufferReadable#read(ByteBuffer buf) method.
*/
class ByteBufferStrategy implements ReaderStrategy {
private final DFSClient dfsClient;
private final ReadStatistics readStatistics;
private final ByteBuffer readBuf;
private final int targetLength;
/**
* The constructor.
* @param readBuf target buffer to read into
* @param readStatistics statistics counter
*/
ByteBufferStrategy(ByteBuffer readBuf,
ReadStatistics readStatistics,
DFSClient dfsClient) {
this.readBuf = readBuf;
this.targetLength = readBuf.remaining();
this.readStatistics = readStatistics;
this.dfsClient = dfsClient;
}
@Override
public ByteBuffer getReadBuffer() {
return readBuf;
}
@Override
public int readFromBlock(BlockReader blockReader) throws IOException {
return readFromBlock(blockReader, readBuf.remaining());
}
@Override
public int readFromBlock(BlockReader blockReader,
int length) throws IOException {
ByteBuffer tmpBuf = readBuf.duplicate();
tmpBuf.limit(tmpBuf.position() + length);
int nRead = blockReader.read(readBuf.slice());
// Only when data are read, update the position
if (nRead > 0) {
readBuf.position(readBuf.position() + nRead);
updateReadStatistics(readStatistics, nRead, blockReader);
dfsClient.updateFileSystemReadStats(blockReader.getNetworkDistance(),
nRead);
}
return nRead;
}
@Override
public int getTargetLength() {
return targetLength;
}
@Override
public int readFromBuffer(ByteBuffer src) {
return readFromBuffer(src, src.remaining());
}
@Override
public int readFromBuffer(ByteBuffer src, int length) {
ByteBuffer dup = src.duplicate();
int newLen = Math.min(readBuf.remaining(), dup.remaining());
newLen = Math.min(newLen, length);
dup.limit(dup.position() + newLen);
readBuf.put(dup);
return newLen;
}
}

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@ -26,6 +26,7 @@ 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;
@ -103,7 +104,7 @@ public class HdfsDataInputStream extends FSDataInputStream {
* be higher than you would expect just by adding up the number of
* bytes read through HdfsDataInputStream.
*/
public DFSInputStream.ReadStatistics getReadStatistics() {
public ReadStatistics getReadStatistics() {
return getDFSInputStream().getReadStatistics();
}

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@ -17,6 +17,8 @@
*/
package org.apache.hadoop.hdfs.util;
import org.apache.hadoop.hdfs.BlockReader;
import org.apache.hadoop.hdfs.ReadStatistics;
import org.slf4j.Logger;
import java.io.IOException;
@ -43,4 +45,18 @@ public class IOUtilsClient {
}
}
public static void updateReadStatistics(ReadStatistics readStatistics,
int nRead, BlockReader blockReader) {
if (nRead <= 0) {
return;
}
if (blockReader.isShortCircuit()) {
readStatistics.addShortCircuitBytes(nRead);
} else if (blockReader.getNetworkDistance() == 0) {
readStatistics.addLocalBytes(nRead);
} else {
readStatistics.addRemoteBytes(nRead);
}
}
}

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@ -23,7 +23,6 @@ import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.DFSInputStream.ReadStatistics;
import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys;
import org.apache.hadoop.hdfs.client.HdfsDataInputStream;
import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
@ -40,7 +39,8 @@ import java.util.LinkedList;
import java.util.UUID;
public class TestExternalBlockReader {
private static final Log LOG = LogFactory.getLog(TestExternalBlockReader.class);
private static final Log LOG =
LogFactory.getLog(TestExternalBlockReader.class);
private static long SEED = 1234;