/**
* Copyright 2014 Ricardo Padilha
*
* 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 net.dsys.snio.impl.channel;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.NoConnectionPendingException;
import java.nio.channels.SelectionKey;
import java.nio.channels.SocketChannel;
import java.util.concurrent.Callable;
import javax.annotation.Nonnegative;
import javax.annotation.Nonnull;
import net.dsys.commons.api.exception.Bug;
import net.dsys.commons.impl.future.SettableCallbackFuture;
import net.dsys.snio.api.buffer.MessageBufferConsumer;
import net.dsys.snio.api.buffer.MessageBufferProducer;
import net.dsys.snio.api.buffer.MessageBufferProvider;
import net.dsys.snio.api.codec.MessageCodec;
import net.dsys.snio.api.limit.RateLimiter;
/**
* @author Ricardo Padilha
*/
final class TCPProcessor extends AbstractProcessor<ByteBuffer> {
private static final int NO_SEQUENCE = -1;
private static final ByteBuffer DUMMY_BUFFER = ByteBuffer.allocate(0);
@Nonnull
private final MessageCodec codec;
@Nonnull
private final RateLimiter limiter;
@Nonnegative
private final int sendSize;
@Nonnegative
private final int receiveSize;
@Nonnull
private ByteBuffer receiveBuffer;
@Nonnull
private ByteBuffer sendBuffer;
private long writeSequence;
TCPProcessor(@Nonnull final MessageCodec codec,
@Nonnull final RateLimiter limiter,
@Nonnull final MessageBufferProvider<ByteBuffer> provider,
@Nonnegative final int sendBufferSize,
@Nonnegative final int receiveBufferSize) {
super(provider);
if (codec == null) {
throw new NullPointerException("codec == null");
}
if (limiter == null) {
throw new NullPointerException("limiter == null");
}
final int sendSize = nearestPowerOfTwo(Math.max(sendBufferSize, codec.getFrameLength()));
final int receiveSize = nearestPowerOfTwo(Math.max(receiveBufferSize, codec.getFrameLength()));
if (sendSize < 1) {
throw new IllegalArgumentException("sendSize < 1");
}
if (receiveSize < 1) {
throw new IllegalArgumentException("receiveSize < 1");
}
this.codec = codec;
this.limiter = limiter;
this.sendSize = sendSize;
this.receiveSize = receiveSize;
this.receiveBuffer = DUMMY_BUFFER; // will be replaced once processor is registered
this.sendBuffer = DUMMY_BUFFER; // will be replaced once processor is registered
this.writeSequence = NO_SEQUENCE;
}
/**
* {@inheritDoc}
*/
@Override
public void connect(final SelectionKey key) {
final SocketChannel client = (SocketChannel) key.channel();
try {
if (client.finishConnect()) {
key.interestOps(key.interestOps() & ~SelectionKey.OP_CONNECT | SelectionKey.OP_READ);
if (!(key.attachment() instanceof TCPChannel)) {
throw new Bug("Unsupported key attachment: " + key.attachment());
}
((TCPChannel<?>) key.attachment()).register();
}
} catch (final IOException | NoConnectionPendingException e) {
getConnectReadFuture().fail(e);
}
}
/**
* {@inheritDoc}
*/
@Override
protected void readRegistered(final SelectionKey key) {
if (key == null) {
throw new NullPointerException("key == null");
}
this.receiveBuffer = ByteBuffer.allocateDirect(receiveSize);
}
/**
* {@inheritDoc}
*/
@Override
protected void writeRegistered(final SelectionKey key) {
if (key == null) {
throw new NullPointerException("key == null");
}
this.sendBuffer = ByteBuffer.allocateDirect(sendSize);
}
/**
* {@inheritDoc}
*/
@Override
public long read(final SelectionKey key) throws IOException {
final SocketChannel channel = (SocketChannel) key.channel();
final MessageBufferProducer<ByteBuffer> chnOut = getChannelOutput();
final MessageBufferProducer<ByteBuffer> appOut = getOutputBuffer();
final long n = channel.read(receiveBuffer);
if (n <= 0) {
// (n < 0) means channel closed from the other side
return n;
}
limiter.receive(n);
receiveBuffer.flip();
while (codec.hasNext(receiveBuffer)) {
try {
final long sequence = chnOut.acquire();
try {
final ByteBuffer msg = chnOut.get(sequence);
msg.clear();
codec.get(receiveBuffer, msg);
msg.flip();
chnOut.attach(sequence, appOut);
} finally {
chnOut.release(sequence);
}
} catch (final InterruptedException e) {
throw new IOException(e);
}
}
if (receiveBuffer.remaining() > 0) {
receiveBuffer.compact();
} else {
receiveBuffer.clear();
}
return n;
}
/**
* {@inheritDoc}
*/
@Override
public long write(final SelectionKey key) throws IOException {
final SocketChannel channel = (SocketChannel) key.channel();
final MessageBufferConsumer<ByteBuffer> chnIn = getChannelInput();
try {
int k = chnIn.remaining();
while (--k >= 0) {
if (writeSequence == NO_SEQUENCE) {
writeSequence = chnIn.acquire();
}
final ByteBuffer msg = chnIn.get(writeSequence);
final int msglen = codec.getEncodedLength(msg);
if (msglen > sendBuffer.capacity()) {
// this message is too big for the current buffer
throw new IOException("codec.length(msg) > sendBuffer.capacity()");
}
if (msglen > sendBuffer.remaining()) {
break;
}
codec.put(msg, sendBuffer);
msg.clear();
chnIn.release(writeSequence);
writeSequence = NO_SEQUENCE;
}
} catch (final InterruptedException e) {
throw new IOException(e);
}
sendBuffer.flip();
limiter.send(sendBuffer.remaining());
final int n = channel.write(sendBuffer);
if (sendBuffer.remaining() > 0) {
sendBuffer.compact();
return n;
}
sendBuffer.clear();
if (chnIn.remaining() == 0) {
disableWriter();
}
return n;
}
/**
* {@inheritDoc}
*/
@Override
protected void shutdown(final SettableCallbackFuture<Void> future, final Callable<Void> task) {
try {
codec.close();
task.call();
future.success(null);
} catch (final Throwable t) {
future.fail(t);
}
}
/**
* @return nearest larger or equal power of two
*/
private static int nearestPowerOfTwo(final int num) {
int n = 0;
if (num > 0) {
n = num - 1;
}
n |= n >> 1;
n |= n >> 2;
n |= n >> 4;
n |= n >> 8;
n |= n >> 16;
n++;
return n;
}
}