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The Java operations layer for the MongoDB Java Driver. Third parties can ' +
'wrap this layer to provide custom higher-level APIs
/*
* Copyright 2008-present 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.internal.connection;
import com.mongodb.MongoException;
import com.mongodb.MongoInternalException;
import com.mongodb.MongoSocketReadException;
import com.mongodb.MongoSocketReadTimeoutException;
import com.mongodb.ServerAddress;
import com.mongodb.connection.AsyncCompletionHandler;
import com.mongodb.connection.SocketSettings;
import com.mongodb.connection.Stream;
import com.mongodb.lang.Nullable;
import org.bson.ByteBuf;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.CompletionHandler;
import java.nio.channels.InterruptedByTimeoutException;
import java.util.Iterator;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.atomic.AtomicReference;
import static com.mongodb.assertions.Assertions.assertTrue;
import static com.mongodb.internal.thread.InterruptionUtil.interruptAndCreateMongoInterruptedException;
import static java.util.concurrent.TimeUnit.MILLISECONDS;
/**
* This class is not part of the public API and may be removed or changed at any time
*/
@SuppressWarnings("deprecation")
public abstract class AsynchronousChannelStream implements Stream {
private final ServerAddress serverAddress;
private final SocketSettings settings;
private final PowerOfTwoBufferPool bufferProvider;
// we use `AtomicReference` to guarantee that we do not call `ExtendedAsynchronousByteChannel.close` concurrently with itself
private final AtomicReference channel;
private volatile boolean isClosed;
public AsynchronousChannelStream(final ServerAddress serverAddress, final SocketSettings settings,
final PowerOfTwoBufferPool bufferProvider) {
this.serverAddress = serverAddress;
this.settings = settings;
this.bufferProvider = bufferProvider;
channel = new AtomicReference<>();
}
public ServerAddress getServerAddress() {
return serverAddress;
}
public SocketSettings getSettings() {
return settings;
}
public PowerOfTwoBufferPool getBufferProvider() {
return bufferProvider;
}
public ExtendedAsynchronousByteChannel getChannel() {
return channel.get();
}
protected void setChannel(final ExtendedAsynchronousByteChannel channel) {
if (isClosed) {
closeChannel(channel);
} else {
assertTrue(this.channel.compareAndSet(null, channel));
if (isClosed) {
closeChannel(this.channel.getAndSet(null));
}
}
}
@Override
public void writeAsync(final List buffers, final AsyncCompletionHandler handler) {
AsyncWritableByteChannelAdapter byteChannel = new AsyncWritableByteChannelAdapter();
Iterator iter = buffers.iterator();
pipeOneBuffer(byteChannel, iter.next(), new AsyncCompletionHandler() {
@Override
public void completed(@Nullable 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 handler) {
readAsync(numBytes, 0, handler);
}
private void readAsync(final int numBytes, final int additionalTimeout, final AsyncCompletionHandler handler) {
ByteBuf buffer = bufferProvider.getBuffer(numBytes);
int timeout = settings.getReadTimeout(MILLISECONDS);
if (timeout > 0 && additionalTimeout > 0) {
timeout += additionalTimeout;
}
getChannel().read(buffer.asNIO(), timeout, MILLISECONDS, null, new BasicCompletionHandler(buffer, handler));
}
@Override
public void open() throws IOException {
FutureAsyncCompletionHandler handler = new FutureAsyncCompletionHandler<>();
openAsync(handler);
handler.getOpen();
}
@Override
public void write(final List buffers) throws IOException {
FutureAsyncCompletionHandler handler = new FutureAsyncCompletionHandler<>();
writeAsync(buffers, handler);
handler.getWrite();
}
@Override
public ByteBuf read(final int numBytes) throws IOException {
FutureAsyncCompletionHandler handler = new FutureAsyncCompletionHandler<>();
readAsync(numBytes, handler);
return handler.getRead();
}
@Override
public boolean supportsAdditionalTimeout() {
return true;
}
@Override
public ByteBuf read(final int numBytes, final int additionalTimeout) throws IOException {
FutureAsyncCompletionHandler handler = new FutureAsyncCompletionHandler<>();
readAsync(numBytes, additionalTimeout, handler);
return handler.getRead();
}
@Override
public ServerAddress getAddress() {
return serverAddress;
}
@Override
public void close() {
isClosed = true;
closeChannel(this.channel.getAndSet(null));
}
private void closeChannel(@Nullable final ExtendedAsynchronousByteChannel channel) {
try {
if (channel != null) {
channel.close();
}
} catch (IOException e) {
// ignore
}
}
@Override
public boolean isClosed() {
return isClosed;
}
@Override
public ByteBuf getBuffer(final int size) {
return bufferProvider.getBuffer(size);
}
private void pipeOneBuffer(final AsyncWritableByteChannelAdapter byteChannel, final ByteBuf byteBuffer,
final AsyncCompletionHandler outerHandler) {
byteChannel.write(byteBuffer.asNIO(), new AsyncCompletionHandler() {
@Override
public void completed(@Nullable 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 {
void write(final ByteBuffer src, final AsyncCompletionHandler handler) {
getChannel().write(src, null, new AsyncWritableByteChannelAdapter.WriteCompletionHandler(handler));
}
private class WriteCompletionHandler extends BaseCompletionHandler {
WriteCompletionHandler(final AsyncCompletionHandler handler) {
super(handler);
}
@Override
public void completed(final Integer result, final Object attachment) {
AsyncCompletionHandler localHandler = getHandlerAndClear();
localHandler.completed(null);
}
@Override
public void failed(final Throwable exc, final Object attachment) {
AsyncCompletionHandler localHandler = getHandlerAndClear();
localHandler.failed(exc);
}
}
}
private final class BasicCompletionHandler extends BaseCompletionHandler {
private final AtomicReference byteBufReference;
private BasicCompletionHandler(final ByteBuf dst, final AsyncCompletionHandler handler) {
super(handler);
this.byteBufReference = new AtomicReference<>(dst);
}
@Override
public void completed(final Integer result, final Void attachment) {
AsyncCompletionHandler 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 {
getChannel().read(localByteBuf.asNIO(), settings.getReadTimeout(MILLISECONDS), MILLISECONDS, null,
new BasicCompletionHandler(localByteBuf, localHandler));
}
}
@Override
public void failed(final Throwable t, final Void attachment) {
AsyncCompletionHandler 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 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 implements CompletionHandler {
private final AtomicReference> handlerReference;
BaseCompletionHandler(final AsyncCompletionHandler handler) {
this.handlerReference = new AtomicReference<>(handler);
}
AsyncCompletionHandler getHandlerAndClear() {
return handlerReference.getAndSet(null);
}
}
static class FutureAsyncCompletionHandler implements AsyncCompletionHandler {
private final CountDownLatch latch = new CountDownLatch(1);
private volatile T result;
private volatile Throwable error;
@Override
public void completed(@Nullable final T result) {
this.result = result;
latch.countDown();
}
@Override
public void failed(final Throwable t) {
this.error = t;
latch.countDown();
}
void getOpen() throws IOException {
get("Opening");
}
void getWrite() throws IOException {
get("Writing to");
}
T getRead() throws IOException {
return get("Reading from");
}
private T get(final String prefix) throws IOException {
try {
latch.await();
} catch (InterruptedException e) {
throw interruptAndCreateMongoInterruptedException(prefix + " the AsynchronousSocketChannelStream failed", e);
}
if (error != null) {
if (error instanceof IOException) {
throw (IOException) error;
} else if (error instanceof MongoException) {
throw (MongoException) error;
} else {
throw new MongoInternalException(prefix + " the TlsChannelStream failed", error);
}
}
return result;
}
}
}