com.signalfx.shaded.jetty.websocket.common.extensions.compress.CompressExtension Maven / Gradle / Ivy
//
// ========================================================================
// Copyright (c) 1995-2019 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
//
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
//
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
//
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
//
package com.signalfx.shaded.jetty.websocket.common.extensions.compress;
import java.io.ByteArrayOutputStream;
import java.nio.ByteBuffer;
import java.util.ArrayDeque;
import java.util.Queue;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.zip.DataFormatException;
import java.util.zip.Deflater;
import java.util.zip.Inflater;
import java.util.zip.ZipException;
import com.signalfx.shaded.jetty.util.BufferUtil;
import com.signalfx.shaded.jetty.util.IteratingCallback;
import com.signalfx.shaded.jetty.util.compression.DeflaterPool;
import com.signalfx.shaded.jetty.util.compression.InflaterPool;
import com.signalfx.shaded.jetty.util.log.Log;
import com.signalfx.shaded.jetty.util.log.Logger;
import com.signalfx.shaded.jetty.websocket.api.BatchMode;
import com.signalfx.shaded.jetty.websocket.api.WriteCallback;
import com.signalfx.shaded.jetty.websocket.api.extensions.Frame;
import com.signalfx.shaded.jetty.websocket.common.OpCode;
import com.signalfx.shaded.jetty.websocket.common.extensions.AbstractExtension;
import com.signalfx.shaded.jetty.websocket.common.frames.DataFrame;
public abstract class CompressExtension extends AbstractExtension
{
protected static final byte[] TAIL_BYTES = new byte[]{0x00, 0x00, (byte)0xFF, (byte)0xFF};
protected static final ByteBuffer TAIL_BYTES_BUF = ByteBuffer.wrap(TAIL_BYTES);
private static final Logger LOG = Log.getLogger(CompressExtension.class);
/**
* Never drop tail bytes 0000FFFF, from any frame type
*/
protected static final int TAIL_DROP_NEVER = 0;
/**
* Always drop tail bytes 0000FFFF, from all frame types
*/
protected static final int TAIL_DROP_ALWAYS = 1;
/**
* Only drop tail bytes 0000FFFF, from fin==true frames
*/
protected static final int TAIL_DROP_FIN_ONLY = 2;
/**
* Always set RSV flag, on all frame types
*/
protected static final int RSV_USE_ALWAYS = 0;
/**
* Only set RSV flag on first frame in multi-frame messages.
*
* Note: this automatically means no-continuation frames have the RSV bit set
*/
protected static final int RSV_USE_ONLY_FIRST = 1;
/**
* Inflater / Decompressed Buffer Size
*/
protected static final int INFLATE_BUFFER_SIZE = 8 * 1024;
/**
* Deflater / Inflater: Maximum Input Buffer Size
*/
protected static final int INPUT_MAX_BUFFER_SIZE = 8 * 1024;
/**
* Inflater : Output Buffer Size
*/
private static final int DECOMPRESS_BUF_SIZE = 8 * 1024;
private final Queue entries = new ArrayDeque<>();
private final IteratingCallback flusher = new Flusher();
private DeflaterPool deflaterPool;
private InflaterPool inflaterPool;
private Deflater deflaterImpl;
private Inflater inflaterImpl;
protected AtomicInteger decompressCount = new AtomicInteger(0);
private int tailDrop = TAIL_DROP_NEVER;
private int rsvUse = RSV_USE_ALWAYS;
protected CompressExtension()
{
tailDrop = getTailDropMode();
rsvUse = getRsvUseMode();
}
public void setInflaterPool(InflaterPool inflaterPool)
{
this.inflaterPool = inflaterPool;
}
public void setDeflaterPool(DeflaterPool deflaterPool)
{
this.deflaterPool = deflaterPool;
}
public Deflater getDeflater()
{
if (deflaterImpl == null)
{
deflaterImpl = deflaterPool.acquire();
}
return deflaterImpl;
}
public Inflater getInflater()
{
if (inflaterImpl == null)
{
inflaterImpl = inflaterPool.acquire();
}
return inflaterImpl;
}
/**
* Indicates use of RSV1 flag for indicating deflation is in use.
*/
@Override
public boolean isRsv1User()
{
return true;
}
/**
* Return the mode of operation for dropping (or keeping) tail bytes in frames generated by compress (outgoing)
*
* @return either {@link #TAIL_DROP_ALWAYS}, {@link #TAIL_DROP_FIN_ONLY}, or {@link #TAIL_DROP_NEVER}
*/
abstract int getTailDropMode();
/**
* Return the mode of operation for RSV flag use in frames generate by compress (outgoing)
*
* @return either {@link #RSV_USE_ALWAYS} or {@link #RSV_USE_ONLY_FIRST}
*/
abstract int getRsvUseMode();
protected void forwardIncoming(Frame frame, ByteAccumulator accumulator)
{
DataFrame newFrame = new DataFrame(frame);
// Unset RSV1 since it's not compressed anymore.
newFrame.setRsv1(false);
ByteBuffer buffer = getBufferPool().acquire(accumulator.getLength(), false);
try
{
BufferUtil.flipToFill(buffer);
accumulator.transferTo(buffer);
newFrame.setPayload(buffer);
nextIncomingFrame(newFrame);
}
finally
{
getBufferPool().release(buffer);
}
}
protected ByteAccumulator newByteAccumulator()
{
int maxSize = Math.max(getPolicy().getMaxTextMessageSize(), getPolicy().getMaxBinaryMessageSize());
return new ByteAccumulator(maxSize);
}
protected void decompress(ByteAccumulator accumulator, ByteBuffer buf) throws DataFormatException
{
if ((buf == null) || (!buf.hasRemaining()))
{
return;
}
byte[] output = new byte[DECOMPRESS_BUF_SIZE];
Inflater inflater = getInflater();
while (buf.hasRemaining() && inflater.needsInput())
{
if (!supplyInput(inflater, buf))
{
LOG.debug("Needed input, but no buffer could supply input");
return;
}
int read;
while ((read = inflater.inflate(output)) >= 0)
{
if (read == 0)
{
LOG.debug("Decompress: read 0 {}", toDetail(inflater));
break;
}
else
{
// do something with output
if (LOG.isDebugEnabled())
{
LOG.debug("Decompressed {} bytes: {}", read, toDetail(inflater));
}
accumulator.copyChunk(output, 0, read);
}
}
}
if (LOG.isDebugEnabled())
{
LOG.debug("Decompress: exiting {}", toDetail(inflater));
}
}
@Override
public void outgoingFrame(Frame frame, WriteCallback callback, BatchMode batchMode)
{
// We use a queue and an IteratingCallback to handle concurrency.
// We must compress and write atomically, otherwise the compression
// context on the other end gets confused.
if (flusher.isFailed())
{
notifyCallbackFailure(callback, new ZipException());
return;
}
FrameEntry entry = new FrameEntry(frame, callback, batchMode);
if (LOG.isDebugEnabled())
LOG.debug("Queuing {}", entry);
offerEntry(entry);
flusher.iterate();
}
private void offerEntry(FrameEntry entry)
{
synchronized (this)
{
entries.offer(entry);
}
}
private FrameEntry pollEntry()
{
synchronized (this)
{
return entries.poll();
}
}
protected void notifyCallbackSuccess(WriteCallback callback)
{
try
{
if (callback != null)
callback.writeSuccess();
}
catch (Throwable x)
{
if (LOG.isDebugEnabled())
LOG.debug("Exception while notifying success of callback " + callback, x);
}
}
protected void notifyCallbackFailure(WriteCallback callback, Throwable failure)
{
try
{
if (callback != null)
callback.writeFailed(failure);
}
catch (Throwable x)
{
if (LOG.isDebugEnabled())
LOG.debug("Exception while notifying failure of callback " + callback, x);
}
}
private static boolean supplyInput(Inflater inflater, ByteBuffer buf)
{
if (buf == null || buf.remaining() <= 0)
{
if (LOG.isDebugEnabled())
{
LOG.debug("No data left left to supply to Inflater");
}
return false;
}
byte[] input;
int inputOffset;
int len;
if (buf.hasArray())
{
// no need to create a new byte buffer, just return this one.
len = buf.remaining();
input = buf.array();
inputOffset = buf.position() + buf.arrayOffset();
buf.position(buf.position() + len);
}
else
{
// Only create an return byte buffer that is reasonable in size
len = Math.min(INPUT_MAX_BUFFER_SIZE, buf.remaining());
input = new byte[len];
inputOffset = 0;
buf.get(input, 0, len);
}
inflater.setInput(input, inputOffset, len);
if (LOG.isDebugEnabled())
{
LOG.debug("Supplied {} input bytes: {}", input.length, toDetail(inflater));
}
return true;
}
private static boolean supplyInput(Deflater deflater, ByteBuffer buf)
{
if (buf == null || buf.remaining() <= 0)
{
if (LOG.isDebugEnabled())
{
LOG.debug("No data left left to supply to Deflater");
}
return false;
}
byte[] input;
int inputOffset;
int len;
if (buf.hasArray())
{
// no need to create a new byte buffer, just return this one.
len = buf.remaining();
input = buf.array();
inputOffset = buf.position() + buf.arrayOffset();
buf.position(buf.position() + len);
}
else
{
// Only create an return byte buffer that is reasonable in size
len = Math.min(INPUT_MAX_BUFFER_SIZE, buf.remaining());
input = new byte[len];
inputOffset = 0;
buf.get(input, 0, len);
}
deflater.setInput(input, inputOffset, len);
if (LOG.isDebugEnabled())
{
LOG.debug("Supplied {} input bytes: {}", input.length, toDetail(deflater));
}
return true;
}
private static String toDetail(Inflater inflater)
{
return String.format("Inflater[finished=%b,read=%d,written=%d,remaining=%d,in=%d,out=%d]", inflater.finished(), inflater.getBytesRead(),
inflater.getBytesWritten(), inflater.getRemaining(), inflater.getTotalIn(), inflater.getTotalOut());
}
private static String toDetail(Deflater deflater)
{
return String.format("Deflater[finished=%b,read=%d,written=%d,in=%d,out=%d]", deflater.finished(), deflater.getBytesRead(), deflater.getBytesWritten(),
deflater.getTotalIn(), deflater.getTotalOut());
}
public static boolean endsWithTail(ByteBuffer buf)
{
if ((buf == null) || (buf.remaining() < TAIL_BYTES.length))
{
return false;
}
int limit = buf.limit();
for (int i = TAIL_BYTES.length; i > 0; i--)
{
if (buf.get(limit - i) != TAIL_BYTES[TAIL_BYTES.length - i])
{
return false;
}
}
return true;
}
@Override
protected void doStop() throws Exception
{
if (deflaterImpl != null)
{
deflaterPool.release(deflaterImpl);
deflaterImpl = null;
}
if (inflaterImpl != null)
{
inflaterPool.release(inflaterImpl);
inflaterImpl = null;
}
super.doStop();
}
@Override
public String toString()
{
return getClass().getSimpleName();
}
private static class FrameEntry
{
private final Frame frame;
private final WriteCallback callback;
private final BatchMode batchMode;
private FrameEntry(Frame frame, WriteCallback callback, BatchMode batchMode)
{
this.frame = frame;
this.callback = callback;
this.batchMode = batchMode;
}
@Override
public String toString()
{
return frame.toString();
}
}
private class Flusher extends IteratingCallback implements WriteCallback
{
private FrameEntry current;
private boolean finished = true;
@Override
public void failed(Throwable x)
{
notifyCallbackFailure(current.callback, x);
// If something went wrong, very likely the compression context
// will be invalid, so we need to fail this IteratingCallback.
LOG.warn(x);
super.failed(x);
}
@Override
protected Action process() throws Exception
{
if (finished)
{
current = pollEntry();
LOG.debug("Processing {}", current);
if (current == null)
return Action.IDLE;
deflate(current);
}
else
{
compress(current, false);
}
return Action.SCHEDULED;
}
private void deflate(FrameEntry entry)
{
Frame frame = entry.frame;
BatchMode batchMode = entry.batchMode;
if (OpCode.isControlFrame(frame.getOpCode()))
{
// Do not deflate control frames
nextOutgoingFrame(frame, this, batchMode);
return;
}
compress(entry, true);
}
private void compress(FrameEntry entry, boolean first)
{
// Get a chunk of the payload to avoid to blow
// the heap if the payload is a huge mapped file.
Frame frame = entry.frame;
ByteBuffer data = frame.getPayload();
if (data == null)
data = BufferUtil.EMPTY_BUFFER;
int remaining = data.remaining();
int outputLength = Math.max(256, data.remaining());
if (LOG.isDebugEnabled())
LOG.debug("Compressing {}: {} bytes in {} bytes chunk", entry, remaining, outputLength);
boolean needsCompress = true;
Deflater deflater = getDeflater();
if (deflater.needsInput() && !supplyInput(deflater, data))
{
// no input supplied
needsCompress = false;
}
ByteArrayOutputStream out = new ByteArrayOutputStream();
byte[] output = new byte[outputLength];
boolean fin = frame.isFin();
// Compress the data
while (needsCompress)
{
int compressed = deflater.deflate(output, 0, outputLength, Deflater.SYNC_FLUSH);
// Append the output for the eventual frame.
if (LOG.isDebugEnabled())
LOG.debug("Wrote {} bytes to output buffer", compressed);
out.write(output, 0, compressed);
if (compressed < outputLength)
{
needsCompress = false;
}
}
ByteBuffer payload = ByteBuffer.wrap(out.toByteArray());
if (payload.remaining() > 0)
{
// Handle tail bytes generated by SYNC_FLUSH.
if (LOG.isDebugEnabled())
LOG.debug("compressed[] bytes = {}", BufferUtil.toDetailString(payload));
if (tailDrop == TAIL_DROP_ALWAYS)
{
if (endsWithTail(payload))
{
payload.limit(payload.limit() - TAIL_BYTES.length);
}
if (LOG.isDebugEnabled())
LOG.debug("payload (TAIL_DROP_ALWAYS) = {}", BufferUtil.toDetailString(payload));
}
else if (tailDrop == TAIL_DROP_FIN_ONLY)
{
if (frame.isFin() && endsWithTail(payload))
{
payload.limit(payload.limit() - TAIL_BYTES.length);
}
if (LOG.isDebugEnabled())
LOG.debug("payload (TAIL_DROP_FIN_ONLY) = {}", BufferUtil.toDetailString(payload));
}
}
else if (fin)
{
// Special case: 7.2.3.6. Generating an Empty Fragment Manually
// https://tools.ietf.org/html/rfc7692#section-7.2.3.6
payload = ByteBuffer.wrap(new byte[]{0x00});
}
if (LOG.isDebugEnabled())
{
LOG.debug("Compressed {}: input:{} -> payload:{}", entry, outputLength, payload.remaining());
}
boolean continuation = frame.getType().isContinuation() || !first;
DataFrame chunk = new DataFrame(frame, continuation);
if (rsvUse == RSV_USE_ONLY_FIRST)
{
chunk.setRsv1(!continuation);
}
else
{
// always set
chunk.setRsv1(true);
}
chunk.setPayload(payload);
chunk.setFin(fin);
nextOutgoingFrame(chunk, this, entry.batchMode);
}
@Override
protected void onCompleteSuccess()
{
// This IteratingCallback never completes.
}
@Override
protected void onCompleteFailure(Throwable x)
{
// Fail all the frames in the queue.
FrameEntry entry;
while ((entry = pollEntry()) != null)
{
notifyCallbackFailure(entry.callback, x);
}
}
@Override
public void writeSuccess()
{
if (finished)
notifyCallbackSuccess(current.callback);
succeeded();
}
@Override
public void writeFailed(Throwable x)
{
failed(x);
}
}
}