/*
* 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.nio.channels.ClosedChannelException;
import java.nio.channels.FileChannel;
import java.util.concurrent.TimeUnit;
import java.util.zip.Deflater;
import io.undertow.server.HttpServerExchange;
import io.undertow.util.ConduitFactory;
import io.undertow.util.Headers;
import org.xnio.IoUtils;
import org.xnio.Pooled;
import org.xnio.XnioIoThread;
import org.xnio.XnioWorker;
import org.xnio.channels.StreamSourceChannel;
import org.xnio.conduits.ConduitWritableByteChannel;
import org.xnio.conduits.Conduits;
import org.xnio.conduits.StreamSinkConduit;
import org.xnio.conduits.WriteReadyHandler;
import static org.xnio.Bits.allAreClear;
import static org.xnio.Bits.anyAreSet;
/**
* Channel that handles deflate compression
*
* @author Stuart Douglas
*/
public class DeflatingStreamSinkConduit implements StreamSinkConduit {
protected final Deflater deflater;
private final ConduitFactory<StreamSinkConduit> conduitFactory;
private final HttpServerExchange exchange;
private StreamSinkConduit next;
private WriteReadyHandler writeReadyHandler;
/**
* The streams buffer. This is freed when the next is shutdown
*/
protected final Pooled<ByteBuffer> currentBuffer;
/**
* there may have been some additional data that did not fit into the first buffer
*/
private ByteBuffer additionalBuffer;
private int state = 0;
private static final int SHUTDOWN = 1;
private static final int NEXT_SHUTDOWN = 1 << 1;
private static final int FLUSHING_BUFFER = 1 << 2;
private static final int WRITES_RESUMED = 1 << 3;
private static final int CLOSED = 1 << 4;
private static final int WRITTEN_TRAILER = 1 << 5;
public DeflatingStreamSinkConduit(final ConduitFactory<StreamSinkConduit> conduitFactory, final HttpServerExchange exchange) {
this(conduitFactory, exchange, Deflater.DEFLATED);
}
protected DeflatingStreamSinkConduit(final ConduitFactory<StreamSinkConduit> conduitFactory, final HttpServerExchange exchange, int deflateLevel) {
deflater = new Deflater(deflateLevel, true);
this.currentBuffer = exchange.getConnection().getBufferPool().allocate();
this.exchange = exchange;
this.conduitFactory = conduitFactory;
}
@Override
public int write(final ByteBuffer src) throws IOException {
if (anyAreSet(SHUTDOWN | CLOSED, state)) {
throw new ClosedChannelException();
}
if (!performFlushIfRequired()) {
return 0;
}
if (src.remaining() == 0) {
return 0;
}
//we may already have some input, if so compress it
if(!deflater.needsInput()) {
deflateData();
if(!deflater.needsInput()) {
return 0;
}
}
byte[] data = new byte[src.remaining()];
src.get(data);
preDeflate(data);
deflater.setInput(data);
deflateData();
return data.length;
}
protected void preDeflate(byte[] data) {
}
@Override
public long write(final ByteBuffer[] srcs, final int offset, final int length) throws IOException {
if (anyAreSet(SHUTDOWN | CLOSED, state)) {
throw new ClosedChannelException();
}
int total = 0;
for (int i = offset; i < offset + length; ++i) {
if (srcs[i].hasRemaining()) {
int ret = write(srcs[i]);
total += ret;
if (ret == 0) {
return total;
}
}
}
return total;
}
@Override
public int writeFinal(ByteBuffer src) throws IOException {
return Conduits.writeFinalBasic(this, src);
}
@Override
public long writeFinal(ByteBuffer[] srcs, int offset, int length) throws IOException {
return Conduits.writeFinalBasic(this, srcs, offset, length);
}
@Override
public long transferFrom(final FileChannel src, final long position, final long count) throws IOException {
if (anyAreSet(SHUTDOWN | CLOSED, state)) {
throw new ClosedChannelException();
}
if (!performFlushIfRequired()) {
return 0;
}
return src.transferTo(position, count, new ConduitWritableByteChannel(this));
}
@Override
public long transferFrom(final StreamSourceChannel source, final long count, final ByteBuffer throughBuffer) throws IOException {
if (anyAreSet(SHUTDOWN | CLOSED, state)) {
throw new ClosedChannelException();
}
if (!performFlushIfRequired()) {
return 0;
}
return IoUtils.transfer(source, count, throughBuffer, new ConduitWritableByteChannel(this));
}
@Override
public XnioWorker getWorker() {
return exchange.getConnection().getWorker();
}
@Override
public void suspendWrites() {
if (next == null) {
state = state & ~WRITES_RESUMED;
} else {
next.suspendWrites();
}
}
@Override
public boolean isWriteResumed() {
if (next == null) {
return anyAreSet(WRITES_RESUMED, state);
} else {
return next.isWriteResumed();
}
}
@Override
public void wakeupWrites() {
if (next == null) {
resumeWrites();
} else {
next.wakeupWrites();
}
}
@Override
public void resumeWrites() {
if (next == null) {
state |= WRITES_RESUMED;
queueWriteListener();
} else {
next.resumeWrites();
}
}
private void queueWriteListener() {
exchange.getConnection().getIoThread().execute(new Runnable() {
@Override
public void run() {
if (writeReadyHandler != null) {
try {
writeReadyHandler.writeReady();
} finally {
//if writes are still resumed queue up another one
if (next == null && isWriteResumed()) {
queueWriteListener();
}
}
}
}
});
}
@Override
public void terminateWrites() throws IOException {
deflater.finish();
state |= SHUTDOWN;
}
@Override
public boolean isWriteShutdown() {
return anyAreSet(state, SHUTDOWN);
}
@Override
public void awaitWritable() throws IOException {
if (next == null) {
return;
} else {
next.awaitWritable();
}
}
@Override
public void awaitWritable(final long time, final TimeUnit timeUnit) throws IOException {
if (next == null) {
return;
} else {
next.awaitWritable(time, timeUnit);
}
}
@Override
public XnioIoThread getWriteThread() {
return exchange.getConnection().getIoThread();
}
@Override
public void setWriteReadyHandler(final WriteReadyHandler handler) {
this.writeReadyHandler = handler;
}
@Override
public boolean flush() throws IOException {
boolean nextCreated = false;
try {
if (anyAreSet(SHUTDOWN, state)) {
if (anyAreSet(NEXT_SHUTDOWN, state)) {
return next.flush();
} else {
if (!performFlushIfRequired()) {
return false;
}
//if the deflater has not been fully flushed we need to flush it
if (!deflater.finished()) {
deflateData();
//if could not fully flush
if (!deflater.finished()) {
return false;
}
}
final ByteBuffer buffer = currentBuffer.getResource();
if (allAreClear(WRITTEN_TRAILER, state)) {
state |= WRITTEN_TRAILER;
byte[] data = getTrailer();
if(data != null) {
if(data.length <= buffer.remaining()) {
buffer.put(data);
} else if(additionalBuffer == null) {
additionalBuffer = ByteBuffer.wrap(data);
} else {
byte[] newData = new byte[additionalBuffer.remaining() + data.length];
int pos = 0;
while (additionalBuffer.hasRemaining()) {
newData[pos++] = additionalBuffer.get();
}
for (byte aData : data) {
newData[pos++] = aData;
}
this.additionalBuffer = ByteBuffer.wrap(newData);
}
}
}
//ok the deflater is flushed, now we need to flush the buffer
if (!anyAreSet(FLUSHING_BUFFER, state)) {
buffer.flip();
state |= FLUSHING_BUFFER;
if (next == null) {
nextCreated = true;
this.next = createNextChannel();
}
}
if (performFlushIfRequired()) {
state |= NEXT_SHUTDOWN;
currentBuffer.free();
next.terminateWrites();
return next.flush();
} else {
return false;
}
}
} else {
return performFlushIfRequired();
}
} finally {
if (nextCreated) {
if (anyAreSet(WRITES_RESUMED, state) && !anyAreSet(NEXT_SHUTDOWN, state)) {
next.resumeWrites();
}
}
}
}
/**
* called before the stream is finally flushed.
*/
protected byte[] getTrailer() {
return null;
}
/**
* The we are in the flushing state then we flush to the underlying stream, otherwise just return true
*
* @return false if there is still more to flush
*/
private boolean performFlushIfRequired() throws IOException {
if (anyAreSet(FLUSHING_BUFFER, state)) {
final ByteBuffer[] bufs = new ByteBuffer[additionalBuffer == null ? 1 : 2];
long totalLength = 0;
bufs[0] = currentBuffer.getResource();
totalLength += bufs[0].remaining();
if (additionalBuffer != null) {
bufs[1] = additionalBuffer;
totalLength += bufs[1].remaining();
}
if (totalLength > 0) {
long total = 0;
long res = 0;
do {
res = next.write(bufs, 0, bufs.length);
total += res;
if (res == 0) {
return false;
}
} while (total < totalLength);
}
additionalBuffer = null;
currentBuffer.getResource().clear();
state = state & ~FLUSHING_BUFFER;
}
return true;
}
private StreamSinkConduit createNextChannel() {
if (deflater.finished()) {
//the deflater was fully flushed before we created the channel. This means that what is in the buffer is
//all there is
int remaining = currentBuffer.getResource().remaining();
if (additionalBuffer != null) {
remaining += additionalBuffer.remaining();
}
exchange.getResponseHeaders().put(Headers.CONTENT_LENGTH, Integer.toString(remaining));
} else {
exchange.getResponseHeaders().remove(Headers.CONTENT_LENGTH);
}
return conduitFactory.create();
}
/**
* Runs the current data through the deflater. As much as possible this will be buffered in the current output
* stream.
*
* @throws IOException
*/
private void deflateData() throws IOException {
//we don't need to flush here, as this should have been called already by the time we get to
//this point
boolean nextCreated = false;
try {
Pooled<ByteBuffer> pooled = this.currentBuffer;
final ByteBuffer outputBuffer = pooled.getResource();
final boolean shutdown = anyAreSet(SHUTDOWN, state);
byte[] buffer = new byte[1024]; //TODO: we should pool this and make it configurable or something
while (!deflater.needsInput() || (shutdown && !deflater.finished())) {
int count = deflater.deflate(buffer);
if (count != 0) {
int remaining = outputBuffer.remaining();
if (remaining > count) {
outputBuffer.put(buffer, 0, count);
} else {
if (remaining == count) {
outputBuffer.put(buffer, 0, count);
} else {
outputBuffer.put(buffer, 0, remaining);
additionalBuffer = ByteBuffer.wrap(buffer, remaining, count - remaining);
}
outputBuffer.flip();
this.state |= FLUSHING_BUFFER;
if (next == null) {
nextCreated = true;
this.next = createNextChannel();
}
if (!performFlushIfRequired()) {
return;
}
}
}
}
} finally {
if (nextCreated) {
if (anyAreSet(WRITES_RESUMED, state)) {
next.resumeWrites();
}
}
}
}
@Override
public void truncateWrites() throws IOException {
if (!anyAreSet(NEXT_SHUTDOWN, state)) {
currentBuffer.free();
}
state |= CLOSED;
next.truncateWrites();
}
}