/*
* 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 io.netty.buffer.Buf;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.MessageBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.AbstractChannel;
import io.netty.channel.Channel;
import io.netty.channel.ChannelConfig;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundByteHandler;
import io.netty.channel.ChannelInboundMessageHandler;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.ChannelPromise;
import io.netty.channel.ChannelStateHandlerAdapter;
import io.netty.channel.DefaultChannelConfig;
import io.netty.channel.EventLoop;
import io.netty.util.internal.PlatformDependent;
import io.netty.util.internal.logging.InternalLogger;
import io.netty.util.internal.logging.InternalLoggerFactory;
import java.net.SocketAddress;
import java.nio.channels.ClosedChannelException;
/**
* Base class for {@link Channel} implementations that are used in an embedded fashion.
*
* @param <O> the type of data that can be written to this {@link Channel}
*/
public abstract class AbstractEmbeddedChannel<O> extends AbstractChannel {
private static final InternalLogger logger = InternalLoggerFactory.getInstance(AbstractEmbeddedChannel.class);
private final EmbeddedEventLoop loop = new EmbeddedEventLoop();
private final ChannelConfig config = new DefaultChannelConfig(this);
private final SocketAddress localAddress = new EmbeddedSocketAddress();
private final SocketAddress remoteAddress = new EmbeddedSocketAddress();
private final MessageBuf<Object> lastInboundMessageBuffer = Unpooled.messageBuffer();
private final ByteBuf lastInboundByteBuffer = Unpooled.buffer();
protected final Object lastOutboundBuffer;
private Throwable lastException;
private int state; // 0 = OPEN, 1 = ACTIVE, 2 = CLOSED
/**
* Create a new instance
*
* @param lastOutboundBuffer the last outbound buffer which will hold all the written data
* @param handlers the @link ChannelHandler}s which will be add in the {@link ChannelPipeline}
*/
AbstractEmbeddedChannel(Object lastOutboundBuffer, ChannelHandler... handlers) {
super(null, null);
if (handlers == null) {
throw new NullPointerException("handlers");
}
this.lastOutboundBuffer = lastOutboundBuffer;
int nHandlers = 0;
boolean hasBuffer = false;
ChannelPipeline p = pipeline();
for (ChannelHandler h: handlers) {
if (h == null) {
break;
}
nHandlers ++;
ChannelHandlerContext ctx = p.addLast(h).context(h);
if (ctx.hasInboundByteBuffer() || ctx.hasOutboundByteBuffer()
|| ctx.hasInboundMessageBuffer() || ctx.hasOutboundMessageBuffer()) {
hasBuffer = true;
}
}
if (nHandlers == 0) {
throw new IllegalArgumentException("handlers is empty.");
}
if (!hasBuffer) {
throw new IllegalArgumentException("handlers does not provide any buffers.");
}
p.addLast(new LastInboundMessageHandler(), new LastInboundByteHandler());
loop.register(this);
}
@Override
public ChannelConfig config() {
return config;
}
@Override
public boolean isOpen() {
return state < 2;
}
@Override
public boolean isActive() {
return state == 1;
}
/**
* Return the last inbound {@link MessageBuf} which will hold all the {@link Object}s that where received
* by this {@link Channel}
*/
public MessageBuf<Object> lastInboundMessageBuffer() {
return lastInboundMessageBuffer;
}
/**
* Return the last inbound {@link ByteBuf} which will hold all the bytes that where received
* by this {@link Channel}
*/
public ByteBuf lastInboundByteBuffer() {
return lastInboundByteBuffer;
}
/**
* Return received data from this {@link Channel}
*/
public Object readInbound() {
if (lastInboundByteBuffer.isReadable()) {
try {
return lastInboundByteBuffer.readBytes(lastInboundByteBuffer.readableBytes());
} finally {
lastInboundByteBuffer.clear();
}
}
return lastInboundMessageBuffer.poll();
}
/**
* Run all tasks that are pending in the {@link EventLoop} for this {@link Channel}
*/
public void runPendingTasks() {
try {
loop.runTasks();
} catch (Exception e) {
recordException(e);
}
}
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);
}
}
/**
* Check if there was any {@link Throwable} received and if so rethrow it.
*/
public void checkException() {
Throwable t = lastException;
if (t == null) {
return;
}
lastException = null;
PlatformDependent.throwException(t);
}
protected final void ensureOpen() {
if (!isOpen()) {
recordException(new ClosedChannelException());
checkException();
}
}
@Override
protected boolean isCompatible(EventLoop loop) {
return loop instanceof EmbeddedEventLoop;
}
@Override
protected SocketAddress localAddress0() {
return isActive()? localAddress : null;
}
@Override
protected SocketAddress remoteAddress0() {
return isActive()? remoteAddress : null;
}
@Override
protected Runnable doRegister() throws Exception {
state = 1;
return null;
}
@Override
protected void doBind(SocketAddress localAddress) throws Exception {
// NOOP
}
@Override
protected void doDisconnect() throws Exception {
doClose();
}
@Override
protected void doClose() throws Exception {
state = 2;
}
@Override
protected Runnable doDeregister() throws Exception {
return new Runnable() {
@Override
public void run() {
runPendingTasks();
}
};
}
@Override
protected void doBeginRead() throws Exception {
// NOOP
}
@Override
protected AbstractUnsafe newUnsafe() {
return new DefaultUnsafe();
}
@Override
protected boolean isFlushPending() {
return false;
}
/**
* Read data froum the outbound. This may return {@code null} if nothing is readable.
*/
public abstract O readOutbound();
/**
* Return the inbound buffer in which inbound messages are stored.
*/
public abstract Buf inboundBuffer();
/**
* Return the last outbound buffer in which all the written outbound messages are stored.
*/
public abstract Buf lastOutboundBuffer();
/**
* Mark this {@link Channel} as finished. Any futher 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() {
close();
runPendingTasks();
checkException();
return lastInboundByteBuffer().isReadable() || !lastInboundMessageBuffer().isEmpty() ||
hasReadableOutboundBuffer();
}
/**
* Write data to the inbound of this {@link Channel}.
*
* @param data data that should be written
* @return bufferReadable returns {@code true} if the write operation did add something to the the inbound buffer
*/
public boolean writeInbound(O data) {
ensureOpen();
writeInbound0(data);
pipeline().fireInboundBufferUpdated();
runPendingTasks();
checkException();
return lastInboundByteBuffer().isReadable() || !lastInboundMessageBuffer().isEmpty();
}
/**
* Write data to the outbound of this {@link Channel}.
*
* @param data data that should be written
* @return bufferReadable returns {@code true} if the write operation did add something to the the outbound buffer
*/
public boolean writeOutbound(Object data) {
ensureOpen();
ChannelFuture future = write(data);
assert future.isDone();
if (future.cause() != null) {
recordException(future.cause());
}
runPendingTasks();
checkException();
return hasReadableOutboundBuffer();
}
/**
* Returns {@code true} if the outbound buffer hold some data which can be read
*/
protected abstract boolean hasReadableOutboundBuffer();
/**
* Add the data to the inbound buffer.
*/
protected abstract void writeInbound0(O data);
private class DefaultUnsafe extends AbstractUnsafe {
@Override
public void connect(SocketAddress remoteAddress,
SocketAddress localAddress, ChannelPromise promise) {
promise.setSuccess();
}
}
private final class LastInboundMessageHandler extends ChannelStateHandlerAdapter
implements ChannelInboundMessageHandler<Object> {
@Override
public MessageBuf<Object> newInboundBuffer(ChannelHandlerContext ctx) throws Exception {
return lastInboundMessageBuffer;
}
@Override
public void freeInboundBuffer(ChannelHandlerContext ctx) throws Exception {
// Do NOT free the buffer.
}
@Override
public void inboundBufferUpdated(ChannelHandlerContext ctx) throws Exception {
// Do nothing.
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
throws Exception {
recordException(cause);
}
}
private final class LastInboundByteHandler extends ChannelStateHandlerAdapter
implements ChannelInboundByteHandler {
@Override
public ByteBuf newInboundBuffer(ChannelHandlerContext ctx) throws Exception {
return lastInboundByteBuffer;
}
@Override
public void discardInboundReadBytes(ChannelHandlerContext ctx) throws Exception {
// nothing
}
@Override
public void freeInboundBuffer(ChannelHandlerContext ctx) throws Exception {
// Do NOT free the buffer.
}
@Override
public void inboundBufferUpdated(ChannelHandlerContext ctx) throws Exception {
// No nothing
}
}
}