/*
 * 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 java.io.IOException;
import java.nio.ByteBuffer;
import java.util.zip.CRC32;
import java.util.zip.Deflater;
import java.util.zip.Inflater;

import org.xnio.conduits.StreamSourceConduit;
import io.undertow.UndertowMessages;
import io.undertow.server.ConduitWrapper;
import io.undertow.server.HttpServerExchange;
import io.undertow.util.ConduitFactory;
import io.undertow.util.ObjectPool;

Author:Stuart Douglas
/** * @author Stuart Douglas */
public class GzipStreamSourceConduit extends InflatingStreamSourceConduit { public static final ConduitWrapper<StreamSourceConduit> WRAPPER = new ConduitWrapper<StreamSourceConduit>() { @Override public StreamSourceConduit wrap(ConduitFactory<StreamSourceConduit> factory, HttpServerExchange exchange) { return new GzipStreamSourceConduit(exchange, factory.create()); } }; 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) }; private final CRC32 crc = new CRC32(); public GzipStreamSourceConduit(HttpServerExchange exchange, StreamSourceConduit next) { super(exchange, next); } public GzipStreamSourceConduit( HttpServerExchange exchange, StreamSourceConduit next, ObjectPool<Inflater> inflaterPool) { super(exchange, next, inflaterPool); } private int totalOut; private int headerRead = 0; private int footerRead = 0; byte[] expectedFooter; protected boolean readHeader(ByteBuffer headerData) throws IOException { while (headerRead < HEADER.length && headerData.hasRemaining()) { byte data = headerData.get(); if (headerRead == 0 && data != HEADER[0]) { throw UndertowMessages.MESSAGES.invalidGzipHeader(); } else if (headerRead == 1 && data != HEADER[1]) { throw UndertowMessages.MESSAGES.invalidGzipHeader(); } headerRead++; } return headerRead == HEADER.length; } protected void readFooter(ByteBuffer buf) throws IOException { if (expectedFooter == null) { byte[] ret = new byte[8]; int checksum = (int) crc.getValue(); int total = totalOut; 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); expectedFooter = ret; } while (buf.hasRemaining() && footerRead < expectedFooter.length) { byte data = buf.get(); if (expectedFooter[footerRead++] != data) { throw UndertowMessages.MESSAGES.invalidGZIPFooter(); } } if (buf.hasRemaining() && footerRead == expectedFooter.length) { throw UndertowMessages.MESSAGES.invalidGZIPFooter(); } } protected void dataDeflated(byte[] data, int off, int len) { crc.update(data, off, len); totalOut += len; } }