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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

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/*
 * 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 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;
    }
}