/*
* Copyright 2012 The Netty Project
*
* The Netty Project licenses this file to you 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.netty.channel.embedded;
import java.net.SocketAddress;
import java.nio.channels.ClosedChannelException;
import java.util.ArrayDeque;
import java.util.Queue;
import io.netty.channel.AbstractChannel;
import io.netty.channel.Channel;
import io.netty.channel.ChannelConfig;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelId;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelMetadata;
import io.netty.channel.ChannelOutboundBuffer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.ChannelPromise;
import io.netty.channel.DefaultChannelConfig;
import io.netty.channel.DefaultChannelPipeline;
import io.netty.channel.EventLoop;
import io.netty.util.ReferenceCountUtil;
import io.netty.util.internal.ObjectUtil;
import io.netty.util.internal.PlatformDependent;
import io.netty.util.internal.RecyclableArrayList;
import io.netty.util.internal.logging.InternalLogger;
import io.netty.util.internal.logging.InternalLoggerFactory;
/**
* Base class for {@link Channel} implementations that are used in an embedded fashion.
*/
public class EmbeddedChannel extends AbstractChannel {
private static final SocketAddress LOCAL_ADDRESS = new EmbeddedSocketAddress();
private static final SocketAddress REMOTE_ADDRESS = new EmbeddedSocketAddress();
private static final ChannelHandler[] EMPTY_HANDLERS = new ChannelHandler[0];
private enum State { OPEN, ACTIVE, CLOSED }
private static final InternalLogger logger = InternalLoggerFactory.getInstance(EmbeddedChannel.class);
private static final ChannelMetadata METADATA_NO_DISCONNECT = new ChannelMetadata(false);
private static final ChannelMetadata METADATA_DISCONNECT = new ChannelMetadata(true);
private final EmbeddedEventLoop loop = new EmbeddedEventLoop();
private final ChannelFutureListener recordExceptionListener = new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture future) throws Exception {
recordException(future);
}
};
private final ChannelMetadata metadata;
private final ChannelConfig config;
private Queue<Object> inboundMessages;
private Queue<Object> outboundMessages;
private Throwable lastException;
private State state;
/**
* Create a new instance with an {@link EmbeddedChannelId} and an empty pipeline.
*/
public EmbeddedChannel() {
this(EMPTY_HANDLERS);
}
/**
* Create a new instance with the specified ID and an empty pipeline.
*
* @param channelId the {@link ChannelId} that will be used to identify this channel
*/
public EmbeddedChannel(ChannelId channelId) {
this(channelId, EMPTY_HANDLERS);
}
/**
* Create a new instance with the pipeline initialized with the specified handlers.
*
* @param handlers the {@link ChannelHandler}s which will be add in the {@link ChannelPipeline}
*/
public EmbeddedChannel(ChannelHandler... handlers) {
this(EmbeddedChannelId.INSTANCE, handlers);
}
/**
* Create a new instance with the pipeline initialized with the specified handlers.
*
* @param hasDisconnect {@code false} if this {@link Channel} will delegate {@link #disconnect()}
* to {@link #close()}, {@link false} otherwise.
* @param handlers the {@link ChannelHandler}s which will be add in the {@link ChannelPipeline}
*/
public EmbeddedChannel(boolean hasDisconnect, ChannelHandler... handlers) {
this(EmbeddedChannelId.INSTANCE, hasDisconnect, handlers);
}
/**
* Create a new instance with the channel ID set to the given ID and the pipeline
* initialized with the specified handlers.
*
* @param channelId the {@link ChannelId} that will be used to identify this channel
* @param handlers the {@link ChannelHandler}s which will be add in the {@link ChannelPipeline}
*/
public EmbeddedChannel(ChannelId channelId, final ChannelHandler... handlers) {
this(channelId, false, handlers);
}
/**
* Create a new instance with the channel ID set to the given ID and the pipeline
* initialized with the specified handlers.
*
* @param channelId the {@link ChannelId} that will be used to identify this channel
* @param hasDisconnect {@code false} if this {@link Channel} will delegate {@link #disconnect()}
* to {@link #close()}, {@link false} otherwise.
* @param handlers the {@link ChannelHandler}s which will be add in the {@link ChannelPipeline}
*/
public EmbeddedChannel(ChannelId channelId, boolean hasDisconnect, final ChannelHandler... handlers) {
super(null, channelId);
metadata = metadata(hasDisconnect);
config = new DefaultChannelConfig(this);
setup(handlers);
}
/**
* Create a new instance with the channel ID set to the given ID and the pipeline
* initialized with the specified handlers.
*
* @param channelId the {@link ChannelId} that will be used to identify this channel
* @param hasDisconnect {@code false} if this {@link Channel} will delegate {@link #disconnect()}
* to {@link #close()}, {@link false} otherwise.
* @param config the {@link ChannelConfig} which will be returned by {@link #config()}.
* @param handlers the {@link ChannelHandler}s which will be add in the {@link ChannelPipeline}
*/
public EmbeddedChannel(ChannelId channelId, boolean hasDisconnect, final ChannelConfig config,
final ChannelHandler... handlers) {
super(null, channelId);
metadata = metadata(hasDisconnect);
this.config = ObjectUtil.checkNotNull(config, "config");
setup(handlers);
}
private static ChannelMetadata metadata(boolean hasDisconnect) {
return hasDisconnect ? METADATA_DISCONNECT : METADATA_NO_DISCONNECT;
}
private void setup(final ChannelHandler... handlers) {
ObjectUtil.checkNotNull(handlers, "handlers");
ChannelPipeline p = pipeline();
p.addLast(new ChannelInitializer<Channel>() {
@Override
protected void initChannel(Channel ch) throws Exception {
ChannelPipeline pipeline = ch.pipeline();
for (ChannelHandler h: handlers) {
if (h == null) {
break;
}
pipeline.addLast(h);
}
}
});
ChannelFuture future = loop.register(this);
assert future.isDone();
}
@Override
protected final DefaultChannelPipeline newChannelPipeline() {
return new EmbeddedChannelPipeline(this);
}
@Override
public ChannelMetadata metadata() {
return metadata;
}
@Override
public ChannelConfig config() {
return config;
}
@Override
public boolean isOpen() {
return state != State.CLOSED;
}
@Override
public boolean isActive() {
return state == State.ACTIVE;
}
/**
* Returns the {@link Queue} which holds all the {@link Object}s that were received by this {@link Channel}.
*/
public Queue<Object> inboundMessages() {
if (inboundMessages == null) {
inboundMessages = new ArrayDeque<Object>();
}
return inboundMessages;
}
/**
* @deprecated use {@link #inboundMessages()}
*/
@Deprecated
public Queue<Object> lastInboundBuffer() {
return inboundMessages();
}
/**
* Returns the {@link Queue} which holds all the {@link Object}s that were written by this {@link Channel}.
*/
public Queue<Object> outboundMessages() {
if (outboundMessages == null) {
outboundMessages = new ArrayDeque<Object>();
}
return outboundMessages;
}
/**
* @deprecated use {@link #outboundMessages()}
*/
@Deprecated
public Queue<Object> lastOutboundBuffer() {
return outboundMessages();
}
/**
* Return received data from this {@link Channel}
*/
@SuppressWarnings("unchecked")
public <T> T readInbound() {
return (T) poll(inboundMessages);
}
/**
* Read data from the outbound. This may return {@code null} if nothing is readable.
*/
@SuppressWarnings("unchecked")
public <T> T readOutbound() {
return (T) poll(outboundMessages);
}
/**
* Write messages to the inbound of this {@link Channel}.
*
* @param msgs the messages to be written
*
* @return {@code true} if the write operation did add something to the inbound buffer
*/
public boolean writeInbound(Object... msgs) {
ensureOpen();
if (msgs.length == 0) {
return isNotEmpty(inboundMessages);
}
ChannelPipeline p = pipeline();
for (Object m: msgs) {
p.fireChannelRead(m);
}
flushInbound(false, voidPromise());
return isNotEmpty(inboundMessages);
}
/**
* Writes one message to the inbound of this {@link Channel} and does not flush it. This
* method is conceptually equivalent to {@link #write(Object)}.
*
* @see #writeOneOutbound(Object)
*/
public ChannelFuture writeOneInbound(Object msg) {
return writeOneInbound(msg, newPromise());
}
/**
* Writes one message to the inbound of this {@link Channel} and does not flush it. This
* method is conceptually equivalent to {@link #write(Object, ChannelPromise)}.
*
* @see #writeOneOutbound(Object, ChannelPromise)
*/
public ChannelFuture writeOneInbound(Object msg, ChannelPromise promise) {
if (checkOpen(true)) {
pipeline().fireChannelRead(msg);
}
return checkException(promise);
}
/**
* Flushes the inbound of this {@link Channel}. This method is conceptually equivalent to {@link #flush()}.
*
* @see #flushOutbound()
*/
public EmbeddedChannel flushInbound() {
flushInbound(true, voidPromise());
return this;
}
private ChannelFuture flushInbound(boolean recordException, ChannelPromise promise) {
if (checkOpen(recordException)) {
pipeline().fireChannelReadComplete();
runPendingTasks();
}
return checkException(promise);
}
/**
* Write messages to the outbound of this {@link Channel}.
*
* @param msgs the messages to be written
* @return bufferReadable returns {@code true} if the write operation did add something to the outbound buffer
*/
public boolean writeOutbound(Object... msgs) {
ensureOpen();
if (msgs.length == 0) {
return isNotEmpty(outboundMessages);
}
RecyclableArrayList futures = RecyclableArrayList.newInstance(msgs.length);
try {
for (Object m: msgs) {
if (m == null) {
break;
}
futures.add(write(m));
}
flushOutbound0();
int size = futures.size();
for (int i = 0; i < size; i++) {
ChannelFuture future = (ChannelFuture) futures.get(i);
if (future.isDone()) {
recordException(future);
} else {
// The write may be delayed to run later by runPendingTasks()
future.addListener(recordExceptionListener);
}
}
checkException();
return isNotEmpty(outboundMessages);
} finally {
futures.recycle();
}
}
/**
* Writes one message to the outbound of this {@link Channel} and does not flush it. This
* method is conceptually equivalent to {@link #write(Object)}.
*
* @see #writeOneInbound(Object)
*/
public ChannelFuture writeOneOutbound(Object msg) {
return writeOneOutbound(msg, newPromise());
}
/**
* Writes one message to the outbound of this {@link Channel} and does not flush it. This
* method is conceptually equivalent to {@link #write(Object, ChannelPromise)}.
*
* @see #writeOneInbound(Object, ChannelPromise)
*/
public ChannelFuture writeOneOutbound(Object msg, ChannelPromise promise) {
if (checkOpen(true)) {
return write(msg, promise);
}
return checkException(promise);
}
/**
* Flushes the outbound of this {@link Channel}. This method is conceptually equivalent to {@link #flush()}.
*
* @see #flushInbound()
*/
public EmbeddedChannel flushOutbound() {
if (checkOpen(true)) {
flushOutbound0();
}
checkException(voidPromise());
return this;
}
private void flushOutbound0() {
// We need to call runPendingTasks first as a ChannelOutboundHandler may used eventloop.execute(...) to
// delay the write on the next eventloop run.
runPendingTasks();
flush();
}
/**
* Mark this {@link Channel} as finished. Any further try to write data to it will fail.
*
* @return bufferReadable returns {@code true} if any of the used buffers has something left to read
*/
public boolean finish() {
return finish(false);
}
/**
* Mark this {@link Channel} as finished and release all pending message in the inbound and outbound buffer.
* Any further try to write data to it will fail.
*
* @return bufferReadable returns {@code true} if any of the used buffers has something left to read
*/
public boolean finishAndReleaseAll() {
return finish(true);
}
/**
* Mark this {@link Channel} as finished. Any further try to write data to it will fail.
*
* @param releaseAll if {@code true} all pending message in the inbound and outbound buffer are released.
* @return bufferReadable returns {@code true} if any of the used buffers has something left to read
*/
private boolean finish(boolean releaseAll) {
close();
try {
checkException();
return isNotEmpty(inboundMessages) || isNotEmpty(outboundMessages);
} finally {
if (releaseAll) {
releaseAll(inboundMessages);
releaseAll(outboundMessages);
}
}
}
/**
* Release all buffered inbound messages and return {@code true} if any were in the inbound buffer, {@code false}
* otherwise.
*/
public boolean releaseInbound() {
return releaseAll(inboundMessages);
}
/**
* Release all buffered outbound messages and return {@code true} if any were in the outbound buffer, {@code false}
* otherwise.
*/
public boolean releaseOutbound() {
return releaseAll(outboundMessages);
}
private static boolean releaseAll(Queue<Object> queue) {
if (isNotEmpty(queue)) {
for (;;) {
Object msg = queue.poll();
if (msg == null) {
break;
}
ReferenceCountUtil.release(msg);
}
return true;
}
return false;
}
private void finishPendingTasks(boolean cancel) {
runPendingTasks();
if (cancel) {
// Cancel all scheduled tasks that are left.
loop.cancelScheduledTasks();
}
}
@Override
public final ChannelFuture close() {
return close(newPromise());
}
@Override
public final ChannelFuture disconnect() {
return disconnect(newPromise());
}
@Override
public final ChannelFuture close(ChannelPromise promise) {
// We need to call runPendingTasks() before calling super.close() as there may be something in the queue
// that needs to be run before the actual close takes place.
runPendingTasks();
ChannelFuture future = super.close(promise);
// Now finish everything else and cancel all scheduled tasks that were not ready set.
finishPendingTasks(true);
return future;
}
@Override
public final ChannelFuture disconnect(ChannelPromise promise) {
ChannelFuture future = super.disconnect(promise);
finishPendingTasks(!metadata.hasDisconnect());
return future;
}
private static boolean isNotEmpty(Queue<Object> queue) {
return queue != null && !queue.isEmpty();
}
private static Object poll(Queue<Object> queue) {
return queue != null ? queue.poll() : null;
}
/**
* Run all tasks (which also includes scheduled tasks) that are pending in the {@link EventLoop}
* for this {@link Channel}
*/
public void runPendingTasks() {
try {
loop.runTasks();
} catch (Exception e) {
recordException(e);
}
try {
loop.runScheduledTasks();
} catch (Exception e) {
recordException(e);
}
}
/**
* Run all pending scheduled tasks in the {@link EventLoop} for this {@link Channel} and return the
* {@code nanoseconds} when the next scheduled task is ready to run. If no other task was scheduled it will return
* {@code -1}.
*/
public long runScheduledPendingTasks() {
try {
return loop.runScheduledTasks();
} catch (Exception e) {
recordException(e);
return loop.nextScheduledTask();
}
}
private void recordException(ChannelFuture future) {
if (!future.isSuccess()) {
recordException(future.cause());
}
}
private void recordException(Throwable cause) {
if (lastException == null) {
lastException = cause;
} else {
logger.warn(
"More than one exception was raised. " +
"Will report only the first one and log others.", cause);
}
}
/**
* Checks for the presence of an {@link Exception}.
*/
private ChannelFuture checkException(ChannelPromise promise) {
Throwable t = lastException;
if (t != null) {
lastException = null;
if (promise.isVoid()) {
PlatformDependent.throwException(t);
}
return promise.setFailure(t);
}
return promise.setSuccess();
}
/**
* Check if there was any {@link Throwable} received and if so rethrow it.
*/
public void checkException() {
checkException(voidPromise());
}
/**
* Returns {@code true} if the {@link Channel} is open and records optionally
* an {@link Exception} if it isn't.
*/
private boolean checkOpen(boolean recordException) {
if (!isOpen()) {
if (recordException) {
recordException(new ClosedChannelException());
}
return false;
}
return true;
}
/**
* Ensure the {@link Channel} is open and if not throw an exception.
*/
protected final void ensureOpen() {
if (!checkOpen(true)) {
checkException();
}
}
@Override
protected boolean isCompatible(EventLoop loop) {
return loop instanceof EmbeddedEventLoop;
}
@Override
protected SocketAddress localAddress0() {
return isActive()? LOCAL_ADDRESS : null;
}
@Override
protected SocketAddress remoteAddress0() {
return isActive()? REMOTE_ADDRESS : null;
}
@Override
protected void doRegister() throws Exception {
state = State.ACTIVE;
}
@Override
protected void doBind(SocketAddress localAddress) throws Exception {
// NOOP
}
@Override
protected void doDisconnect() throws Exception {
if (!metadata.hasDisconnect()) {
doClose();
}
}
@Override
protected void doClose() throws Exception {
state = State.CLOSED;
}
@Override
protected void doBeginRead() throws Exception {
// NOOP
}
@Override
protected AbstractUnsafe newUnsafe() {
return new DefaultUnsafe();
}
@Override
protected void doWrite(ChannelOutboundBuffer in) throws Exception {
for (;;) {
Object msg = in.current();
if (msg == null) {
break;
}
ReferenceCountUtil.retain(msg);
handleOutboundMessage(msg);
in.remove();
}
}
/**
* Called for each outbound message.
*
* @see #doWrite(ChannelOutboundBuffer)
*/
protected void handleOutboundMessage(Object msg) {
outboundMessages().add(msg);
}
/**
* Called for each inbound message.
*/
protected void handleInboundMessage(Object msg) {
inboundMessages().add(msg);
}
private class DefaultUnsafe extends AbstractUnsafe {
@Override
public void connect(SocketAddress remoteAddress, SocketAddress localAddress, ChannelPromise promise) {
safeSetSuccess(promise);
}
}
private final class EmbeddedChannelPipeline extends DefaultChannelPipeline {
public EmbeddedChannelPipeline(EmbeddedChannel channel) {
super(channel);
}
@Override
protected void onUnhandledInboundException(Throwable cause) {
recordException(cause);
}
@Override
protected void onUnhandledInboundMessage(Object msg) {
handleInboundMessage(msg);
}
}
}