io.undertow.conduits.GzipStreamSinkConduit Maven / Gradle / Ivy
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* 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 conduitFactory, HttpServerExchange exchange) {
this(conduitFactory, exchange, Deflater.DEFAULT_COMPRESSION);
}
public GzipStreamSinkConduit(
ConduitFactory conduitFactory,
HttpServerExchange exchange,
int deflateLevel) {
this(conduitFactory, exchange, newInstanceDeflaterPool(deflateLevel));
}
public GzipStreamSinkConduit(
ConduitFactory 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;
}
}