/*
* Copyright 2011 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 org.jboss.netty.channel;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import org.jboss.netty.logging.InternalLogger;
import org.jboss.netty.logging.InternalLoggerFactory;
import org.jboss.netty.util.internal.ConversionUtil;
/**
* A {@link ChannelPipeline} that might perform better at the cost of
* disabled dynamic insertion and removal of {@link ChannelHandler}s.
* An attempt to insert, remove, or replace a handler in this pipeline will
* trigger an {@link UnsupportedOperationException}.
*
* @deprecated use {@link DefaultChannelPipeline}
*/
@Deprecated
public class StaticChannelPipeline implements ChannelPipeline {
// FIXME Code duplication with DefaultChannelPipeline
static final InternalLogger logger = InternalLoggerFactory.getInstance(StaticChannelPipeline.class);
private volatile Channel channel;
private volatile ChannelSink sink;
private final StaticChannelHandlerContext[] contexts;
private final int lastIndex;
private final Map<String, StaticChannelHandlerContext> name2ctx =
new HashMap<String, StaticChannelHandlerContext>(4);
/**
* Creates a new pipeline from the specified handlers.
* The names of the specified handlers are generated automatically;
* the first handler's name is {@code "0"}, the second handler's name is
* {@code "1"}, the third handler's name is {@code "2"}, and so on.
*/
public StaticChannelPipeline(ChannelHandler... handlers) {
if (handlers == null) {
throw new NullPointerException("handlers");
}
if (handlers.length == 0) {
throw new IllegalArgumentException("no handlers specified");
}
// Get the number of first non-null handlers.
StaticChannelHandlerContext[] contexts =
new StaticChannelHandlerContext[handlers.length];
int nContexts;
for (nContexts = 0; nContexts < contexts.length; nContexts ++) {
ChannelHandler h = handlers[nContexts];
if (h == null) {
break;
}
}
if (nContexts == contexts.length) {
this.contexts = contexts;
lastIndex = contexts.length - 1;
} else {
this.contexts = contexts =
new StaticChannelHandlerContext[nContexts];
lastIndex = nContexts - 1;
}
// Initialize the first non-null handlers only.
for (int i = 0; i < nContexts; i ++) {
ChannelHandler h = handlers[i];
String name = ConversionUtil.toString(i);
StaticChannelHandlerContext ctx =
new StaticChannelHandlerContext(i, name, h);
contexts[i] = ctx;
name2ctx.put(name, ctx);
}
for (ChannelHandlerContext ctx: contexts) {
callBeforeAdd(ctx);
callAfterAdd(ctx);
}
}
public ChannelFuture execute(Runnable task) {
return getSink().execute(this, task);
}
public Channel getChannel() {
return channel;
}
public ChannelSink getSink() {
ChannelSink sink = this.sink;
if (sink == null) {
return DefaultChannelPipeline.discardingSink;
}
return sink;
}
public void attach(Channel channel, ChannelSink sink) {
if (channel == null) {
throw new NullPointerException("channel");
}
if (sink == null) {
throw new NullPointerException("sink");
}
if (this.channel != null || this.sink != null) {
throw new IllegalStateException("attached already");
}
this.channel = channel;
this.sink = sink;
}
public boolean isAttached() {
return sink != null;
}
public void addFirst(String name, ChannelHandler handler) {
throw new UnsupportedOperationException();
}
public void addLast(String name, ChannelHandler handler) {
throw new UnsupportedOperationException();
}
public void addBefore(String baseName, String name, ChannelHandler handler) {
throw new UnsupportedOperationException();
}
public void addAfter(String baseName, String name, ChannelHandler handler) {
throw new UnsupportedOperationException();
}
public void remove(ChannelHandler handler) {
throw new UnsupportedOperationException();
}
public ChannelHandler remove(String name) {
throw new UnsupportedOperationException();
}
public <T extends ChannelHandler> T remove(Class<T> handlerType) {
throw new UnsupportedOperationException();
}
public ChannelHandler removeFirst() {
throw new UnsupportedOperationException();
}
public ChannelHandler removeLast() {
throw new UnsupportedOperationException();
}
public void replace(ChannelHandler oldHandler, String newName, ChannelHandler newHandler) {
throw new UnsupportedOperationException();
}
public ChannelHandler replace(String oldName, String newName, ChannelHandler newHandler) {
throw new UnsupportedOperationException();
}
public <T extends ChannelHandler> T replace(
Class<T> oldHandlerType, String newName, ChannelHandler newHandler) {
throw new UnsupportedOperationException();
}
private void callBeforeAdd(ChannelHandlerContext ctx) {
if (!(ctx.getHandler() instanceof LifeCycleAwareChannelHandler)) {
return;
}
LifeCycleAwareChannelHandler h =
(LifeCycleAwareChannelHandler) ctx.getHandler();
try {
h.beforeAdd(ctx);
} catch (Throwable t) {
throw new ChannelHandlerLifeCycleException(
h.getClass().getName() +
".beforeAdd() has thrown an exception; not adding.", t);
}
}
private void callAfterAdd(ChannelHandlerContext ctx) {
if (!(ctx.getHandler() instanceof LifeCycleAwareChannelHandler)) {
return;
}
LifeCycleAwareChannelHandler h =
(LifeCycleAwareChannelHandler) ctx.getHandler();
try {
h.afterAdd(ctx);
} catch (Throwable t) {
boolean removed = false;
try {
callBeforeRemove(ctx);
callAfterRemove(ctx);
removed = true;
} catch (Throwable t2) {
logger.warn("Failed to remove a handler: " + ctx.getName(), t2);
}
if (removed) {
throw new ChannelHandlerLifeCycleException(
h.getClass().getName() +
".afterAdd() has thrown an exception; removed.", t);
} else {
throw new ChannelHandlerLifeCycleException(
h.getClass().getName() +
".afterAdd() has thrown an exception; also failed to remove.", t);
}
}
}
private void callBeforeRemove(ChannelHandlerContext ctx) {
if (!(ctx.getHandler() instanceof LifeCycleAwareChannelHandler)) {
return;
}
LifeCycleAwareChannelHandler h =
(LifeCycleAwareChannelHandler) ctx.getHandler();
try {
h.beforeRemove(ctx);
} catch (Throwable t) {
throw new ChannelHandlerLifeCycleException(
h.getClass().getName() +
".beforeRemove() has thrown an exception; not removing.", t);
}
}
private void callAfterRemove(ChannelHandlerContext ctx) {
if (!(ctx.getHandler() instanceof LifeCycleAwareChannelHandler)) {
return;
}
LifeCycleAwareChannelHandler h =
(LifeCycleAwareChannelHandler) ctx.getHandler();
try {
h.afterRemove(ctx);
} catch (Throwable t) {
throw new ChannelHandlerLifeCycleException(
h.getClass().getName() +
".afterRemove() has thrown an exception.", t);
}
}
public ChannelHandler getFirst() {
return contexts[0].getHandler();
}
public ChannelHandler getLast() {
return contexts[contexts.length - 1].getHandler();
}
public ChannelHandler get(String name) {
StaticChannelHandlerContext ctx = name2ctx.get(name);
if (ctx == null) {
return null;
} else {
return ctx.getHandler();
}
}
@SuppressWarnings("unchecked")
public <T extends ChannelHandler> T get(Class<T> handlerType) {
ChannelHandlerContext ctx = getContext(handlerType);
if (ctx == null) {
return null;
} else {
return (T) ctx.getHandler();
}
}
public ChannelHandlerContext getContext(String name) {
if (name == null) {
throw new NullPointerException("name");
}
return name2ctx.get(name);
}
public ChannelHandlerContext getContext(ChannelHandler handler) {
if (handler == null) {
throw new NullPointerException("handler");
}
for (StaticChannelHandlerContext ctx: contexts) {
if (ctx.getHandler() == handler) {
return ctx;
}
}
return null;
}
public ChannelHandlerContext getContext(Class<? extends ChannelHandler> handlerType) {
if (handlerType == null) {
throw new NullPointerException("handlerType");
}
for (StaticChannelHandlerContext ctx: contexts) {
if (handlerType.isAssignableFrom(ctx.getHandler().getClass())) {
return ctx;
}
}
return null;
}
public List<String> getNames() {
List<String> list = new ArrayList<String>();
for (StaticChannelHandlerContext ctx: contexts) {
list.add(ctx.getName());
}
return list;
}
public Map<String, ChannelHandler> toMap() {
Map<String, ChannelHandler> map = new LinkedHashMap<String, ChannelHandler>();
for (StaticChannelHandlerContext ctx: contexts) {
map.put(ctx.getName(), ctx.getHandler());
}
return map;
}
/**
* Returns the {@link String} representation of this pipeline.
*/
@Override
public String toString() {
StringBuilder buf = new StringBuilder();
buf.append(getClass().getSimpleName());
buf.append('{');
for (StaticChannelHandlerContext ctx: contexts) {
buf.append('(');
buf.append(ctx.getName());
buf.append(" = ");
buf.append(ctx.getHandler().getClass().getName());
buf.append(')');
buf.append(", ");
}
buf.replace(buf.length() - 2, buf.length(), "}");
return buf.toString();
}
public void sendUpstream(ChannelEvent e) {
StaticChannelHandlerContext head = getActualUpstreamContext(0);
if (head == null) {
logger.warn(
"The pipeline contains no upstream handlers; discarding: " + e);
return;
}
sendUpstream(head, e);
}
void sendUpstream(StaticChannelHandlerContext ctx, ChannelEvent e) {
try {
((ChannelUpstreamHandler) ctx.getHandler()).handleUpstream(ctx, e);
} catch (Throwable t) {
notifyHandlerException(e, t);
}
}
public void sendDownstream(ChannelEvent e) {
StaticChannelHandlerContext tail = getActualDownstreamContext(lastIndex);
if (tail == null) {
try {
getSink().eventSunk(this, e);
return;
} catch (Throwable t) {
notifyHandlerException(e, t);
return;
}
}
sendDownstream(tail, e);
}
void sendDownstream(StaticChannelHandlerContext ctx, ChannelEvent e) {
if (e instanceof UpstreamMessageEvent) {
throw new IllegalArgumentException("cannot send an upstream event to downstream");
}
try {
((ChannelDownstreamHandler) ctx.getHandler()).handleDownstream(ctx, e);
} catch (Throwable t) {
// Unlike an upstream event, a downstream event usually has an
// incomplete future which is supposed to be updated by ChannelSink.
// However, if an exception is raised before the event reaches at
// ChannelSink, the future is not going to be updated, so we update
// here.
e.getFuture().setFailure(t);
notifyHandlerException(e, t);
}
}
StaticChannelHandlerContext getActualUpstreamContext(int index) {
for (int i = index; i < contexts.length; i ++) {
StaticChannelHandlerContext ctx = contexts[i];
if (ctx.canHandleUpstream()) {
return ctx;
}
}
return null;
}
StaticChannelHandlerContext getActualDownstreamContext(int index) {
for (int i = index; i >= 0; i --) {
StaticChannelHandlerContext ctx = contexts[i];
if (ctx.canHandleDownstream()) {
return ctx;
}
}
return null;
}
protected void notifyHandlerException(ChannelEvent e, Throwable t) {
if (e instanceof ExceptionEvent) {
logger.warn(
"An exception was thrown by a user handler " +
"while handling an exception event (" + e + ")", t);
return;
}
ChannelPipelineException pe;
if (t instanceof ChannelPipelineException) {
pe = (ChannelPipelineException) t;
} else {
pe = new ChannelPipelineException(t);
}
try {
sink.exceptionCaught(this, e, pe);
} catch (Exception e1) {
logger.warn("An exception was thrown by an exception handler.", e1);
}
}
private final class StaticChannelHandlerContext implements ChannelHandlerContext {
private final int index;
private final String name;
private final ChannelHandler handler;
private final boolean canHandleUpstream;
private final boolean canHandleDownstream;
private volatile Object attachment;
StaticChannelHandlerContext(
int index, String name, ChannelHandler handler) {
if (name == null) {
throw new NullPointerException("name");
}
if (handler == null) {
throw new NullPointerException("handler");
}
canHandleUpstream = handler instanceof ChannelUpstreamHandler;
canHandleDownstream = handler instanceof ChannelDownstreamHandler;
if (!canHandleUpstream && !canHandleDownstream) {
throw new IllegalArgumentException(
"handler must be either " +
ChannelUpstreamHandler.class.getName() + " or " +
ChannelDownstreamHandler.class.getName() + '.');
}
this.index = index;
this.name = name;
this.handler = handler;
}
public Channel getChannel() {
return getPipeline().getChannel();
}
public ChannelPipeline getPipeline() {
return StaticChannelPipeline.this;
}
public boolean canHandleDownstream() {
return canHandleDownstream;
}
public boolean canHandleUpstream() {
return canHandleUpstream;
}
public ChannelHandler getHandler() {
return handler;
}
public String getName() {
return name;
}
public Object getAttachment() {
return attachment;
}
public void setAttachment(Object attachment) {
this.attachment = attachment;
}
public void sendDownstream(ChannelEvent e) {
StaticChannelHandlerContext prev = getActualDownstreamContext(index - 1);
if (prev == null) {
try {
getSink().eventSunk(StaticChannelPipeline.this, e);
} catch (Throwable t) {
notifyHandlerException(e, t);
}
} else {
StaticChannelPipeline.this.sendDownstream(prev, e);
}
}
public void sendUpstream(ChannelEvent e) {
StaticChannelHandlerContext next = getActualUpstreamContext(index + 1);
if (next != null) {
StaticChannelPipeline.this.sendUpstream(next, e);
}
}
}
}