/*
* 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 com.jcraft.jzlib.JZlib;
import com.jcraft.jzlib.ZStream;
import org.apache.sshd.common.Compression;
import org.apache.sshd.common.NamedFactory;
import org.apache.sshd.common.SshConstants;
import org.apache.sshd.common.SshException;
import org.apache.sshd.common.util.Buffer;
/**
* ZLib based Compression.
*
* @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a>
*/
public class CompressionZlib implements Compression {
/**
* Named factory for the ZLib Compression.
*/
public static class Factory implements NamedFactory<Compression> {
public String getName() {
return "zlib";
}
public Compression create() {
return new CompressionZlib();
}
}
static private final int BUF_SIZE = 4096;
private ZStream stream;
private byte[] tmpbuf = new byte[BUF_SIZE];
/**
* Create a new instance of a ZLib base compression
*/
public CompressionZlib() {
}
public boolean isDelayed() {
return false;
}
public void init(Type type, int level) {
stream = new ZStream();
if (type == Type.Deflater) {
stream.deflateInit(level);
} else {
stream.inflateInit();
}
}
public void compress(Buffer buffer) throws IOException {
stream.next_in = buffer.array();
stream.next_in_index = buffer.rpos();
stream.avail_in = buffer.available();
buffer.wpos(buffer.rpos());
do {
stream.next_out = tmpbuf;
stream.next_out_index = 0;
stream.avail_out = BUF_SIZE;
int status = stream.deflate(JZlib.Z_PARTIAL_FLUSH);
switch (status) {
case JZlib.Z_OK:
buffer.putRawBytes(tmpbuf, 0, BUF_SIZE - stream.avail_out);
break;
default:
throw new SshException(SshConstants.SSH2_DISCONNECT_COMPRESSION_ERROR, "compress: deflate returned " + status);
}
}
while (stream.avail_out == 0);
}
public void uncompress(Buffer from, Buffer to) throws IOException {
stream.next_in = from.array();
stream.next_in_index = from.rpos();
stream.avail_in = from.available();
while (true) {
stream.next_out = tmpbuf;
stream.next_out_index = 0;
stream.avail_out = BUF_SIZE;
int status = stream.inflate(JZlib.Z_PARTIAL_FLUSH);
switch (status) {
case JZlib.Z_OK:
to.putRawBytes(tmpbuf, 0, BUF_SIZE - stream.avail_out);
break;
case JZlib.Z_BUF_ERROR:
return;
default:
throw new SshException(SshConstants.SSH2_DISCONNECT_COMPRESSION_ERROR, "uncompress: inflate returned " + status);
}
}
}
}