/**
* Helios, OpenSource Monitoring
* Brought to you by the Helios Development Group
*
* Copyright 2007, Helios Development Group and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*
*/
package org.helios.apmrouter.nash.streams;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;
import org.helios.apmrouter.nash.handler.NashRequestHandler;
import org.helios.apmrouter.nash.handler.NashStreamHandler;
import org.helios.apmrouter.nash.streams.NashRequestChannelFactory;
import org.helios.apmrouter.nash.streams.NashRequestHandlerStreamServer;
import org.jboss.netty.bootstrap.ServerBootstrap;
import org.jboss.netty.channel.ChannelHandler;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.handler.execution.ExecutionHandler;
import org.jboss.netty.handler.execution.OrderedMemoryAwareThreadPoolExecutor;
import org.jboss.netty.logging.InternalLogger;
import org.jboss.netty.logging.InternalLoggerFactory;
/**
* <p>Title: NashRequestHandlerStreamServer</p>
* <p>Description: Creates local Netty server endpoints identified by and listening on virtual sockets named after the
* name of the nailgun command that the owning request handler iss servicing.</p>
* <p>Company: Helios Development Group LLC</p>
* @author Whitehead (nwhitehead AT heliosdev DOT org)
* <p><code>org.helios.apmrouter.nash.streams.NashRequestHandlerStreamServer</code></p>
*/
public class NashRequestHandlerStreamServer {
/** The singleton instance */
private static volatile NashRequestHandlerStreamServer instance = null;
/** The singleton instance ctor lock */
private static final Object lock = new Object();
/** The internal logger */
protected final InternalLogger log = InternalLoggerFactory.getInstance(getClass());
/** A map of server bootstraps keyed by the command name that owning request handler is handling */
protected final Map<String, ServerBootstrap> commandServers = new ConcurrentHashMap<String, ServerBootstrap>();
/** The thread factory providing threads to the execution handler */
protected final ThreadFactory threadFactory = new ThreadFactory(){
public Thread newThread(Runnable r) {
Thread t = new Thread(r, "StreamServerThread#" + serial.incrementAndGet());
t.setDaemon(true);
return t;
}
};
/** A serial number factory for the executor threads */
protected final AtomicLong serial = new AtomicLong(0L);
/*
* Need to specify some configurability here.
*/
/** The request handling thread pool */
protected final OrderedMemoryAwareThreadPoolExecutor threadPool;
/** The execution handler to handle all stream actions passed to the request handler */
protected final ExecutionHandler executionHandler;
/**
* Returns the singleton NashRequestHandlerStreamServer instance
* @return the singleton NashRequestHandlerStreamServer instance
*/
public static NashRequestHandlerStreamServer getInstance() {
if(instance==null) {
synchronized(lock) {
if(instance==null) {
instance = new NashRequestHandlerStreamServer();
}
}
}
return instance;
}
/**
* Creates a new NashRequestHandlerStreamServer
*/
private NashRequestHandlerStreamServer() {
threadPool = new OrderedMemoryAwareThreadPoolExecutor(10, 0, 0, 60, TimeUnit.SECONDS, threadFactory);
executionHandler = new ExecutionHandler(threadPool);
}
/**
* Creates a new StreamServer through which the NashRequestDecoder can locate the correct handler for a given command,
* hand off the decoded request and initiate a stream processor to route the incoming STDIN stream from the nailgun client.
* @param requestHandler The request handler to which decoded nailgun requests will be dispatched to
* into a form that the request handler wants to process it. If this map is null, the request handler is assumed to not support processing the STDIN stream.
*/
/*
* NOTE: Right now, NailgunRequestHandlers MUST implement NashStreamHandler
* but we want to separate the two, so that if NashStreamHandler is NOT implemented,
* the the request handler will not handle STDIN. The request decoder must be aware whether or not
* the request handler supports STDIN so it knows to start the streaming (or not).
*/
public void newCommandHandlerStreamServer(NashRequestHandler requestHandler) {
Map<String, ChannelHandler> channelHandlers = ((NashStreamHandler<?>)requestHandler).getChannelHandlers();
String commandName = requestHandler.getCommandName().trim().toUpperCase();
ServerBootstrap sb = commandServers.get(commandName);
if(sb==null) {
synchronized(commandServers) {
ChannelPipeline pipeline = Channels.pipeline();
if(channelHandlers!=null) {
for(Map.Entry<String, ChannelHandler> entry: channelHandlers.entrySet()) {
pipeline.addLast(entry.getKey(), entry.getValue());
}
}
pipeline.addFirst("execution", executionHandler);
ServerBootstrap sboot = new ServerBootstrap(new NashRequestChannelFactory(Channels.pipelineFactory(pipeline)));
commandServers.put(commandName, sboot);
log.info("\n\t============================\n\tRegistered Nailgun Command Handler for [" + commandName + "]\n\t============================\n");
}
} else {
throw new IllegalStateException("A command server for the command [" + commandName + "] is already registered", new Throwable());
}
}
}