/*
* Copyright (c) 2008-2014 MongoDB, Inc.
*
* 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 com.mongodb.connection;
import com.mongodb.MongoSocketOpenException;
import com.mongodb.MongoSocketReadException;
import com.mongodb.MongoSocketReadTimeoutException;
import com.mongodb.ServerAddress;
import org.bson.ByteBuf;
import java.io.IOException;
import java.net.ConnectException;
import java.net.StandardSocketOptions;
import java.nio.ByteBuffer;
import java.nio.channels.AsynchronousSocketChannel;
import java.nio.channels.CompletionHandler;
import java.nio.channels.InterruptedByTimeoutException;
import java.util.Iterator;
import java.util.List;
import java.util.concurrent.atomic.AtomicReference;
import static com.mongodb.assertions.Assertions.isTrue;
import static java.util.concurrent.TimeUnit.MILLISECONDS;
final class AsynchronousSocketChannelStream implements Stream {
private final ServerAddress serverAddress;
private final SocketSettings settings;
private final BufferProvider bufferProvider;
private volatile AsynchronousSocketChannel channel;
private volatile boolean isClosed;
AsynchronousSocketChannelStream(final ServerAddress serverAddress, final SocketSettings settings,
final BufferProvider bufferProvider) {
this.serverAddress = serverAddress;
this.settings = settings;
this.bufferProvider = bufferProvider;
}
@Override
public ByteBuf getBuffer(final int size) {
return bufferProvider.getBuffer(size);
}
@Override
public void open() throws IOException {
FutureAsyncCompletionHandler<Void> handler = new FutureAsyncCompletionHandler<Void>();
openAsync(handler);
handler.getOpen();
}
@Override
public void openAsync(final AsyncCompletionHandler<Void> handler) {
isTrue("unopened", channel == null);
try {
channel = AsynchronousSocketChannel.open();
channel.setOption(StandardSocketOptions.TCP_NODELAY, true);
channel.setOption(StandardSocketOptions.SO_KEEPALIVE, settings.isKeepAlive());
if (settings.getReceiveBufferSize() > 0) {
channel.setOption(StandardSocketOptions.SO_RCVBUF, settings.getReceiveBufferSize());
}
if (settings.getSendBufferSize() > 0) {
channel.setOption(StandardSocketOptions.SO_SNDBUF, settings.getSendBufferSize());
}
channel.connect(serverAddress.getSocketAddress(), null, new OpenCompletionHandler(handler));
} catch (IOException e) {
handler.failed(new MongoSocketOpenException("Exception opening socket", serverAddress, e));
} catch (Throwable t) {
handler.failed(t);
}
}
@Override
public void write(final List<ByteBuf> buffers) throws IOException {
FutureAsyncCompletionHandler<Void> handler = new FutureAsyncCompletionHandler<Void>();
writeAsync(buffers, handler);
handler.getWrite();
}
@Override
public ByteBuf read(final int numBytes) throws IOException {
FutureAsyncCompletionHandler<ByteBuf> handler = new FutureAsyncCompletionHandler<ByteBuf>();
readAsync(numBytes, handler);
return handler.getRead();
}
@Override
public void writeAsync(final List<ByteBuf> buffers, final AsyncCompletionHandler<Void> handler) {
final AsyncWritableByteChannel byteChannel = new AsyncWritableByteChannelAdapter();
final Iterator<ByteBuf> iter = buffers.iterator();
pipeOneBuffer(byteChannel, iter.next(), new AsyncCompletionHandler<Void>() {
@Override
public void completed(final Void t) {
if (iter.hasNext()) {
pipeOneBuffer(byteChannel, iter.next(), this);
} else {
handler.completed(null);
}
}
@Override
public void failed(final Throwable t) {
handler.failed(t);
}
});
}
@Override
public void readAsync(final int numBytes, final AsyncCompletionHandler<ByteBuf> handler) {
ByteBuf buffer = bufferProvider.getBuffer(numBytes);
channel.read(buffer.asNIO(), settings.getReadTimeout(MILLISECONDS), MILLISECONDS, null,
new BasicCompletionHandler(buffer, handler));
}
@Override
public ServerAddress getAddress() {
return serverAddress;
}
/**
* Closes the connection.
*/
@Override
public void close() {
try {
if (channel != null) {
channel.close();
}
} catch (IOException e) { // NOPMD
// ignore
} finally {
channel = null;
isClosed = true;
}
}
@Override
public boolean isClosed() {
return isClosed;
}
private void pipeOneBuffer(final AsyncWritableByteChannel byteChannel, final ByteBuf byteBuffer,
final AsyncCompletionHandler<Void> outerHandler) {
byteChannel.write(byteBuffer.asNIO(), new AsyncCompletionHandler<Void>() {
@Override
public void completed(final Void t) {
if (byteBuffer.hasRemaining()) {
byteChannel.write(byteBuffer.asNIO(), this);
} else {
outerHandler.completed(null);
}
}
@Override
public void failed(final Throwable t) {
outerHandler.failed(t);
}
});
}
private class AsyncWritableByteChannelAdapter implements AsyncWritableByteChannel {
@Override
public void write(final ByteBuffer src, final AsyncCompletionHandler<Void> handler) {
channel.write(src, null, new WriteCompletionHandler(handler));
}
private class WriteCompletionHandler extends BaseCompletionHandler<Void, Integer, Object> {
WriteCompletionHandler(final AsyncCompletionHandler<Void> handler) {
super(handler);
}
@Override
public void completed(final Integer result, final Object attachment) {
AsyncCompletionHandler<Void> localHandler = getHandlerAndClear();
localHandler.completed(null);
}
@Override
public void failed(final Throwable exc, final Object attachment) {
AsyncCompletionHandler<Void> localHandler = getHandlerAndClear();
localHandler.failed(exc);
}
}
}
private final class BasicCompletionHandler extends BaseCompletionHandler<ByteBuf, Integer, Void> {
private final AtomicReference<ByteBuf> byteBufReference;
private BasicCompletionHandler(final ByteBuf dst, final AsyncCompletionHandler<ByteBuf> handler) {
super(handler);
this.byteBufReference = new AtomicReference<ByteBuf>(dst);
}
@Override
public void completed(final Integer result, final Void attachment) {
AsyncCompletionHandler<ByteBuf> localHandler = getHandlerAndClear();
ByteBuf localByteBuf = byteBufReference.getAndSet(null);
if (result == -1) {
localByteBuf.release();
localHandler.failed(new MongoSocketReadException("Prematurely reached end of stream", serverAddress));
} else if (!localByteBuf.hasRemaining()) {
localByteBuf.flip();
localHandler.completed(localByteBuf);
} else {
channel.read(localByteBuf.asNIO(), settings.getReadTimeout(MILLISECONDS), MILLISECONDS, null,
new BasicCompletionHandler(localByteBuf, localHandler));
}
}
@Override
public void failed(final Throwable t, final Void attachment) {
AsyncCompletionHandler<ByteBuf> localHandler = getHandlerAndClear();
ByteBuf localByteBuf = byteBufReference.getAndSet(null);
localByteBuf.release();
if (t instanceof InterruptedByTimeoutException) {
localHandler.failed(new MongoSocketReadTimeoutException("Timeout while receiving message", serverAddress, t));
} else {
localHandler.failed(t);
}
}
}
private class OpenCompletionHandler extends BaseCompletionHandler<Void, Void, Object> {
OpenCompletionHandler(final AsyncCompletionHandler<Void> handler) {
super(handler);
}
@Override
public void completed(final Void result, final Object attachment) {
AsyncCompletionHandler<Void> localHandler = getHandlerAndClear();
localHandler.completed(null);
}
@Override
public void failed(final Throwable exc, final Object attachment) {
AsyncCompletionHandler<Void> localHandler = getHandlerAndClear();
if (exc instanceof ConnectException) {
localHandler.failed(new MongoSocketOpenException("Exception opening socket", getAddress(), exc));
} else {
localHandler.failed(exc);
}
}
}
// Private base class for all CompletionHandler implementors that ensures the upstream handler is
// set to null before it is used. This is to work around an observed issue with implementations of
// AsynchronousSocketChannel that fail to clear references to handlers stored in instance fields of
// the class.
private abstract static class BaseCompletionHandler<T, V, A> implements CompletionHandler<V, A> {
private final AtomicReference<AsyncCompletionHandler<T>> handlerReference;
BaseCompletionHandler(final AsyncCompletionHandler<T> handler) {
this.handlerReference = new AtomicReference<AsyncCompletionHandler<T>>(handler);
}
protected AsyncCompletionHandler<T> getHandlerAndClear() {
return handlerReference.getAndSet(null);
}
}
}