/*
* JBoss, Home of Professional Open Source.
* Copyright 2014 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* Licensed 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 io.undertow.conduits;
import io.undertow.server.
Connectors;
import io.undertow.server.
HttpServerExchange;
import io.undertow.util.
ConduitFactory;
import io.undertow.util.
ObjectPool;
import org.xnio.conduits.
StreamSinkConduit;
import java.util.zip.
CRC32;
import java.util.zip.
Deflater;
/**
* @author Stuart Douglas
*/
public class
GzipStreamSinkConduit extends
DeflatingStreamSinkConduit {
/*
* GZIP header magic number.
*/
private static final int
GZIP_MAGIC = 0x8b1f;
private static final byte[]
HEADER = new byte[]{
(byte)
GZIP_MAGIC, // Magic number (short)
(byte) (
GZIP_MAGIC >> 8), // Magic number (short)
Deflater.
DEFLATED, // Compression method (CM)
0, // Flags (FLG)
0, // Modification time MTIME (int)
0, // Modification time MTIME (int)
0, // Modification time MTIME (int)
0, // Modification time MTIME (int)
0, // Extra flags (XFLG)
0 // Operating system (OS)
};
/**
* CRC-32 of uncompressed data.
*/
protected
CRC32 crc = new
CRC32();
public
GzipStreamSinkConduit(
ConduitFactory<
StreamSinkConduit>
conduitFactory,
HttpServerExchange exchange) {
this(
conduitFactory,
exchange,
Deflater.
DEFAULT_COMPRESSION);
}
public
GzipStreamSinkConduit(
ConduitFactory<
StreamSinkConduit>
conduitFactory,
HttpServerExchange exchange,
int
deflateLevel) {
this(
conduitFactory,
exchange,
newInstanceDeflaterPool(
deflateLevel));
}
public
GzipStreamSinkConduit(
ConduitFactory<
StreamSinkConduit>
conduitFactory,
HttpServerExchange exchange,
ObjectPool deflaterPool) {
super(
conduitFactory,
exchange,
deflaterPool);
writeHeader();
Connectors.
updateResponseBytesSent(
exchange,
HEADER.length);
}
private void
writeHeader() {
currentBuffer.
getBuffer().
put(
HEADER);
}
@
Override
protected void
preDeflate(byte[]
data) {
crc.
update(
data);
}
@
Override
protected byte[]
getTrailer() {
byte[]
ret = new byte[8];
int
checksum = (int)
crc.
getValue();
int
total =
deflater.
getTotalIn();
ret[0] = (byte) ((
checksum) & 0xFF);
ret[1] = (byte) ((
checksum >> 8) & 0xFF);
ret[2] = (byte) ((
checksum >> 16) & 0xFF);
ret[3] = (byte) ((
checksum >> 24) & 0xFF);
ret[4] = (byte) ((
total) & 0xFF);
ret[5] = (byte) ((
total >> 8) & 0xFF);
ret[6] = (byte) ((
total >> 16) & 0xFF);
ret[7] = (byte) ((
total >> 24) & 0xFF);
return
ret;
}
}