org.apache.hadoop.hbase.regionserver.wal.CompressionContext Maven / Gradle / Ivy
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/*
* 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.hbase.regionserver.wal;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.util.EnumMap;
import java.util.Map;
import org.apache.commons.io.IOUtils;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseInterfaceAudience;
import org.apache.hadoop.hbase.io.BoundedDelegatingInputStream;
import org.apache.hadoop.hbase.io.TagCompressionContext;
import org.apache.hadoop.hbase.io.compress.Compression;
import org.apache.hadoop.hbase.io.util.Dictionary;
import org.apache.hadoop.io.compress.Compressor;
import org.apache.hadoop.io.compress.Decompressor;
import org.apache.yetus.audience.InterfaceAudience;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Context that holds the various dictionaries for compression in WAL.
*
* CompressionContexts are not expected to be shared among threads. Multithreaded use may produce
* unexpected results.
*/
@InterfaceAudience.LimitedPrivate({ HBaseInterfaceAudience.COPROC, HBaseInterfaceAudience.PHOENIX })
public class CompressionContext {
private static final Logger LOG = LoggerFactory.getLogger(CompressionContext.class);
public static final String ENABLE_WAL_TAGS_COMPRESSION =
"hbase.regionserver.wal.tags.enablecompression";
public static final String ENABLE_WAL_VALUE_COMPRESSION =
"hbase.regionserver.wal.value.enablecompression";
public static final String WAL_VALUE_COMPRESSION_TYPE =
"hbase.regionserver.wal.value.compression.type";
public enum DictionaryIndex {
REGION,
TABLE,
FAMILY,
QUALIFIER,
ROW
}
/**
* Encapsulates the compression algorithm and its streams that we will use for value compression
* in this WAL.
*/
static class ValueCompressor {
static final int IO_BUFFER_SIZE = 64 * 1024; // bigger buffer improves large edit compress ratio
private final Compression.Algorithm algorithm;
private Compressor compressor;
private Decompressor decompressor;
private BoundedDelegatingInputStream lowerIn;
private ByteArrayOutputStream lowerOut;
private InputStream compressedIn;
private OutputStream compressedOut;
public ValueCompressor(Compression.Algorithm algorithm) {
this.algorithm = algorithm;
}
public Compression.Algorithm getAlgorithm() {
return algorithm;
}
public byte[] compress(byte[] valueArray, int valueOffset, int valueLength) throws IOException {
if (compressedOut == null) {
// Create the output streams here the first time around.
lowerOut = new ByteArrayOutputStream();
if (compressor == null) {
compressor = algorithm.getCompressor();
}
compressedOut = algorithm.createCompressionStream(lowerOut, compressor, IO_BUFFER_SIZE);
}
compressedOut.write(valueArray, valueOffset, valueLength);
compressedOut.flush();
final byte[] compressed = lowerOut.toByteArray();
lowerOut.reset(); // Reset now to minimize the overhead of keeping around the BAOS
return compressed;
}
public void decompress(InputStream in, int inLength, byte[] outArray, int outOffset,
int outLength) throws IOException {
// Our input is a sequence of bounded byte ranges (call them segments), with
// BoundedDelegatingInputStream providing a way to switch in a new segment when the
// previous segment has been fully consumed.
// Create the input streams here the first time around.
if (compressedIn == null) {
lowerIn = new BoundedDelegatingInputStream(in, inLength);
if (decompressor == null) {
decompressor = algorithm.getDecompressor();
}
compressedIn = algorithm.createDecompressionStream(lowerIn, decompressor, IO_BUFFER_SIZE);
} else {
lowerIn.setDelegate(in, inLength);
}
if (outLength == 0) {
// The BufferedInputStream will return earlier and skip reading anything if outLength == 0,
// but in fact for an empty value, the compressed output still contains some metadata so the
// compressed size is not 0, so here we need to manually skip inLength bytes otherwise the
// next read on this stream will start from an invalid position and cause critical problem,
// such as data loss when splitting wal or replicating wal.
IOUtils.skipFully(in, inLength);
} else {
IOUtils.readFully(compressedIn, outArray, outOffset, outLength);
}
}
public void clear() {
if (compressedOut != null) {
try {
compressedOut.close();
} catch (IOException e) {
LOG.warn("Exception closing compressed output stream", e);
}
}
compressedOut = null;
if (lowerOut != null) {
try {
lowerOut.close();
} catch (IOException e) {
LOG.warn("Exception closing lower output stream", e);
}
}
lowerOut = null;
if (compressedIn != null) {
try {
compressedIn.close();
} catch (IOException e) {
LOG.warn("Exception closing compressed input stream", e);
}
}
compressedIn = null;
if (lowerIn != null) {
try {
lowerIn.close();
} catch (IOException e) {
LOG.warn("Exception closing lower input stream", e);
}
}
lowerIn = null;
if (compressor != null) {
compressor.reset();
}
if (decompressor != null) {
decompressor.reset();
}
}
}
private final Map dictionaries =
new EnumMap<>(DictionaryIndex.class);
// Context used for compressing tags
TagCompressionContext tagCompressionContext = null;
ValueCompressor valueCompressor = null;
public CompressionContext(Class dictType, boolean recoveredEdits,
boolean hasTagCompression, boolean hasValueCompression,
Compression.Algorithm valueCompressionType) throws SecurityException, NoSuchMethodException,
InstantiationException, IllegalAccessException, InvocationTargetException, IOException {
Constructor dictConstructor = dictType.getConstructor();
for (DictionaryIndex dictionaryIndex : DictionaryIndex.values()) {
Dictionary newDictionary = dictConstructor.newInstance();
dictionaries.put(dictionaryIndex, newDictionary);
}
if (recoveredEdits) {
getDictionary(DictionaryIndex.REGION).init(1);
getDictionary(DictionaryIndex.TABLE).init(1);
} else {
getDictionary(DictionaryIndex.REGION).init(Short.MAX_VALUE);
getDictionary(DictionaryIndex.TABLE).init(Short.MAX_VALUE);
}
getDictionary(DictionaryIndex.ROW).init(Short.MAX_VALUE);
getDictionary(DictionaryIndex.FAMILY).init(Byte.MAX_VALUE);
getDictionary(DictionaryIndex.QUALIFIER).init(Byte.MAX_VALUE);
if (hasTagCompression) {
tagCompressionContext = new TagCompressionContext(dictType, Short.MAX_VALUE);
}
if (hasValueCompression && valueCompressionType != null) {
valueCompressor = new ValueCompressor(valueCompressionType);
}
}
public CompressionContext(Class dictType, boolean recoveredEdits,
boolean hasTagCompression) throws SecurityException, NoSuchMethodException,
InstantiationException, IllegalAccessException, InvocationTargetException, IOException {
this(dictType, recoveredEdits, hasTagCompression, false, null);
}
public boolean hasTagCompression() {
return tagCompressionContext != null;
}
public boolean hasValueCompression() {
return valueCompressor != null;
}
public Dictionary getDictionary(Enum dictIndex) {
return dictionaries.get(dictIndex);
}
public ValueCompressor getValueCompressor() {
return valueCompressor;
}
void clear() {
for (Dictionary dictionary : dictionaries.values()) {
dictionary.clear();
}
if (tagCompressionContext != null) {
tagCompressionContext.clear();
}
if (valueCompressor != null) {
valueCompressor.clear();
}
}
public static Compression.Algorithm getValueCompressionAlgorithm(Configuration conf) {
if (conf.getBoolean(ENABLE_WAL_VALUE_COMPRESSION, true)) {
String compressionType = conf.get(WAL_VALUE_COMPRESSION_TYPE);
if (compressionType != null) {
return Compression.getCompressionAlgorithmByName(compressionType);
}
return Compression.Algorithm.GZ;
}
return Compression.Algorithm.NONE;
}
}