org.glassfish.grizzly.compression.zip.GZipFilter Maven / Gradle / Ivy
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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 GZipFilter using default buffer sizes.
*/
public GZipFilter() {
this(512, 512);
}
/**
* Construct GZipFilter 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 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 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.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();
}
}
}