/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 2010-2011 Oracle and/or its affiliates. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
* or packager/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at packager/legal/LICENSE.txt.
*
* GPL Classpath Exception:
* Oracle designates this particular file as subject to the "Classpath"
* exception as provided by Oracle in the GPL Version 2 section of the License
* file that accompanied this code.
*
* Modifications:
* If applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
* "Portions Copyright [year] [name of copyright owner]"
*
* Contributor(s):
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*/
package org.glassfish.grizzly.compression.zip;
import org.glassfish.grizzly.Buffer;
import org.glassfish.grizzly.Connection;
import org.glassfish.grizzly.TransformationResult;
import org.glassfish.grizzly.filterchain.BaseFilter;
import org.glassfish.grizzly.filterchain.FilterChainContext;
import org.glassfish.grizzly.filterchain.NextAction;
import org.glassfish.grizzly.memory.Buffers;
import java.io.IOException;
/**
* This class implements a {@link org.glassfish.grizzly.filterchain.Filter} which
* encodes/decodes data in the GZIP format.
*
* @author Alexey Stashok
*/
public class GZipFilter extends BaseFilter {
private final GZipDecoder decoder;
private final GZipEncoder encoder;
/**
* Construct <tt>GZipFilter</tt> using default buffer sizes.
*/
public GZipFilter() {
this(512, 512);
}
/**
* Construct <tt>GZipFilter</tt> using specific buffer sizes.
* @param inBufferSize input buffer size
* @param outBufferSize output buffer size
*/
public GZipFilter(int inBufferSize, int outBufferSize) {
this.decoder = new GZipDecoder(inBufferSize);
this.encoder = new GZipEncoder(outBufferSize);
}
/**
* Method perform the clean up of GZIP encoding/decoding state on a closed
* {@link Connection}.
*
* @param ctx Context of {@link FilterChainContext} processing.
* @return the next action
* @throws IOException
*/
@Override
public NextAction handleClose(FilterChainContext ctx) throws IOException {
final Connection connection = ctx.getConnection();
decoder.release(connection);
encoder.release(connection);
return super.handleClose(ctx);
}
/**
* Method decodes GZIP encoded data stored in {@link FilterChainContext#getMessage()} and,
* as the result, produces a {@link Buffer} with a plain data.
* @param ctx Context of {@link FilterChainContext} processing.
*
* @return the next action
* @throws IOException
*/
@Override
public NextAction handleRead(FilterChainContext ctx) throws IOException {
final Connection connection = ctx.getConnection();
final Buffer input = (Buffer) ctx.getMessage();
final TransformationResult<Buffer, Buffer> result =
decoder.transform(connection, input);
final Buffer remainder = result.getExternalRemainder();
if (remainder == null) {
input.tryDispose();
} else {
input.shrink();
}
try {
switch (result.getStatus()) {
case COMPLETE: {
ctx.setMessage(result.getMessage());
return ctx.getInvokeAction(remainder);
}
case INCOMPLETE: {
return ctx.getStopAction(remainder);
}
case ERROR: {
throw new IllegalStateException("GZip decode error. Code: "
+ result.getErrorCode() + " Description: "
+ result.getErrorDescription());
}
default:
throw new IllegalStateException("Unexpected status: " +
result.getStatus());
}
} finally {
result.recycle();
}
}
/**
* Method compresses plain data stored in {@link FilterChainContext#getMessage()} and,
* as the result, produces a {@link Buffer} with a GZIP compressed data.
* @param ctx Context of {@link FilterChainContext} processing.
*
* @return the next action
* @throws IOException
*/
@Override
public NextAction handleWrite(FilterChainContext ctx) throws IOException {
final Connection connection = ctx.getConnection();
final Buffer input = (Buffer) ctx.getMessage();
final TransformationResult<Buffer, Buffer> result =
encoder.transform(connection, input);
input.dispose();
try {
switch (result.getStatus()) {
case COMPLETE:
case INCOMPLETE: {
final Buffer readyBuffer = result.getMessage();
final Buffer finishBuffer = encoder.finish(connection);
final Buffer resultBuffer = Buffers.appendBuffers(
connection.getTransport().getMemoryManager(),
readyBuffer, finishBuffer);
if (resultBuffer != null) {
ctx.setMessage(resultBuffer);
return ctx.getInvokeAction();
} else {
return ctx.getStopAction();
}
}
case ERROR: {
throw new IllegalStateException("GZip decode error. Code: "
+ result.getErrorCode() + " Description: "
+ result.getErrorDescription());
}
default:
throw new IllegalStateException("Unexpected status: " +
result.getStatus());
}
} finally {
result.recycle();
}
}
}