org.apache.hadoop.io.compress.zlib.ZlibFactory 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.io.compress.zlib;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.compress.Compressor;
import org.apache.hadoop.io.compress.Decompressor;
import org.apache.hadoop.io.compress.DirectDecompressor;
import org.apache.hadoop.io.compress.zlib.ZlibCompressor.CompressionLevel;
import org.apache.hadoop.io.compress.zlib.ZlibCompressor.CompressionStrategy;
import org.apache.hadoop.util.NativeCodeLoader;
import org.apache.hadoop.thirdparty.com.google.common.annotations.VisibleForTesting;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A collection of factories to create the right
* zlib/gzip compressor/decompressor instances.
*
*/
public class ZlibFactory {
private static final Logger LOG =
LoggerFactory.getLogger(ZlibFactory.class);
private static boolean nativeZlibLoaded = false;
static {
loadNativeZLib();
}
/**
* Load native library and set the flag whether to use native library. The
* method is also used for reset the flag modified by setNativeZlibLoaded
*/
@VisibleForTesting
public static void loadNativeZLib() {
if (NativeCodeLoader.isNativeCodeLoaded()) {
nativeZlibLoaded = ZlibCompressor.isNativeZlibLoaded() &&
ZlibDecompressor.isNativeZlibLoaded();
if (nativeZlibLoaded) {
LOG.info("Successfully loaded & initialized native-zlib library");
} else {
LOG.warn("Failed to load/initialize native-zlib library");
}
}
}
/**
* Set the flag whether to use native library. Used for testing non-native
* libraries
*
*/
@VisibleForTesting
public static void setNativeZlibLoaded(final boolean isLoaded) {
ZlibFactory.nativeZlibLoaded = isLoaded;
}
/**
* Check if native-zlib code is loaded & initialized correctly and
* can be loaded for this job.
*
* @param conf configuration
* @return true if native-zlib is loaded & initialized
* and can be loaded for this job, else false
*/
public static boolean isNativeZlibLoaded(Configuration conf) {
return nativeZlibLoaded;
}
public static String getLibraryName() {
return ZlibCompressor.getLibraryName();
}
/**
* Return the appropriate type of the zlib compressor.
*
* @param conf configuration
* @return the appropriate type of the zlib compressor.
*/
public static Class
getZlibCompressorType(Configuration conf) {
return (isNativeZlibLoaded(conf)) ?
ZlibCompressor.class : BuiltInZlibDeflater.class;
}
/**
* Return the appropriate implementation of the zlib compressor.
*
* @param conf configuration
* @return the appropriate implementation of the zlib compressor.
*/
public static Compressor getZlibCompressor(Configuration conf) {
return (isNativeZlibLoaded(conf)) ?
new ZlibCompressor(conf) :
new BuiltInZlibDeflater(ZlibFactory.getCompressionLevel(conf).compressionLevel());
}
/**
* Return the appropriate type of the zlib decompressor.
*
* @param conf configuration
* @return the appropriate type of the zlib decompressor.
*/
public static Class
getZlibDecompressorType(Configuration conf) {
return (isNativeZlibLoaded(conf)) ?
ZlibDecompressor.class : BuiltInZlibInflater.class;
}
/**
* Return the appropriate implementation of the zlib decompressor.
*
* @param conf configuration
* @return the appropriate implementation of the zlib decompressor.
*/
public static Decompressor getZlibDecompressor(Configuration conf) {
return (isNativeZlibLoaded(conf)) ?
new ZlibDecompressor() : new BuiltInZlibInflater();
}
/**
* Return the appropriate implementation of the zlib direct decompressor.
*
* @param conf configuration
* @return the appropriate implementation of the zlib decompressor.
*/
public static DirectDecompressor getZlibDirectDecompressor(Configuration conf) {
return (isNativeZlibLoaded(conf)) ?
new ZlibDecompressor.ZlibDirectDecompressor() : null;
}
public static void setCompressionStrategy(Configuration conf,
CompressionStrategy strategy) {
conf.setEnum("zlib.compress.strategy", strategy);
}
public static CompressionStrategy getCompressionStrategy(Configuration conf) {
return conf.getEnum("zlib.compress.strategy",
CompressionStrategy.DEFAULT_STRATEGY);
}
public static void setCompressionLevel(Configuration conf,
CompressionLevel level) {
conf.setEnum("zlib.compress.level", level);
}
public static CompressionLevel getCompressionLevel(Configuration conf) {
return conf.getEnum("zlib.compress.level",
CompressionLevel.DEFAULT_COMPRESSION);
}
}