org.apache.sshd.common.compression.CompressionZlib 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.sshd.common.compression;
import java.io.IOException;
import java.util.zip.DataFormatException;
import java.util.zip.Deflater;
import java.util.zip.Inflater;
import org.apache.sshd.common.util.buffer.Buffer;
/**
* ZLib based Compression.
*
* @author Apache MINA SSHD Project
*/
public class CompressionZlib extends BaseCompression {
private static final int BUF_SIZE = 4096;
private byte[] tmpbuf = new byte[BUF_SIZE];
private Deflater compresser;
private Inflater decompresser;
/**
* Create a new instance of a ZLib base compression
*/
public CompressionZlib() {
this(BuiltinCompressions.Constants.ZLIB);
}
protected CompressionZlib(String name) {
super(name);
}
@Override
public boolean isDelayed() {
return false;
}
@Override
public void init(Type type, int level) {
compresser = new Deflater(level);
decompresser = new Inflater();
}
@Override
public void compress(Buffer buffer) throws IOException {
compresser.setInput(buffer.array(), buffer.rpos(), buffer.available());
buffer.wpos(buffer.rpos());
for (int len = compresser.deflate(tmpbuf, 0, tmpbuf.length, Deflater.SYNC_FLUSH);
len > 0;
len = compresser.deflate(tmpbuf, 0, tmpbuf.length, Deflater.SYNC_FLUSH)) {
buffer.putRawBytes(tmpbuf, 0, len);
}
}
@Override
public void uncompress(Buffer from, Buffer to) throws IOException {
decompresser.setInput(from.array(), from.rpos(), from.available());
try {
for (int len = decompresser.inflate(tmpbuf); len > 0; len = decompresser.inflate(tmpbuf)) {
to.putRawBytes(tmpbuf, 0, len);
}
} catch (DataFormatException e) {
throw new IOException("Error decompressing data", e);
}
}
}