| /* |
| * 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 java.io.IOException; |
| import java.util.zip.Deflater; |
| |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.io.compress.Compressor; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| |
| /** |
| * A wrapper around java.util.zip.Deflater to make it conform |
| * to org.apache.hadoop.io.compress.Compressor interface. |
| * |
| */ |
| public class BuiltInZlibDeflater extends Deflater implements Compressor { |
| |
| private static final Log LOG = LogFactory.getLog(BuiltInZlibDeflater.class); |
| |
| public BuiltInZlibDeflater(int level, boolean nowrap) { |
| super(level, nowrap); |
| } |
| |
| public BuiltInZlibDeflater(int level) { |
| super(level); |
| } |
| |
| public BuiltInZlibDeflater() { |
| super(); |
| } |
| |
| public synchronized int compress(byte[] b, int off, int len) |
| throws IOException { |
| return super.deflate(b, off, len); |
| } |
| |
| /** |
| * reinit the compressor with the given configuration. It will reset the |
| * compressor's compression level and compression strategy. Different from |
| * <tt>ZlibCompressor</tt>, <tt>BuiltInZlibDeflater</tt> only support three |
| * kind of compression strategy: FILTERED, HUFFMAN_ONLY and DEFAULT_STRATEGY. |
| * It will use DEFAULT_STRATEGY as default if the configured compression |
| * strategy is not supported. |
| */ |
| @Override |
| public void reinit(Configuration conf) { |
| reset(); |
| if (conf == null) { |
| return; |
| } |
| setLevel(ZlibFactory.getCompressionLevel(conf).compressionLevel()); |
| final ZlibCompressor.CompressionStrategy strategy = |
| ZlibFactory.getCompressionStrategy(conf); |
| try { |
| setStrategy(strategy.compressionStrategy()); |
| } catch (IllegalArgumentException ill) { |
| LOG.warn(strategy + " not supported by BuiltInZlibDeflater."); |
| setStrategy(DEFAULT_STRATEGY); |
| } |
| LOG.debug("Reinit compressor with new compression configuration"); |
| } |
| } |