//
   //  ========================================================================
   //  Copyright (c) 1995-2012 Mort Bay Consulting Pty. Ltd.
   //  ------------------------------------------------------------------------
   //  All rights reserved. This program and the accompanying materials
   //  are made available under the terms of the Eclipse Public License v1.0
   //  and Apache License v2.0 which accompanies this distribution.
   //
   //      The Eclipse Public License is available at
  //      http://www.eclipse.org/legal/epl-v10.html
  //
  //      The Apache License v2.0 is available at
  //      http://www.opensource.org/licenses/apache2.0.php
  //
  //  You may elect to redistribute this code under either of these licenses.
  //  ========================================================================
  //
  
  package org.eclipse.jetty.server;
  
  import java.io.IOException;
  import java.net.Socket;
  import java.nio.ByteBuffer;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.LinkedHashMap;
  import java.util.List;
  import java.util.Locale;
  import java.util.Map;
  import java.util.concurrent.CountDownLatch;
  import java.util.concurrent.Executor;
  import java.util.concurrent.Future;
  import java.util.concurrent.TimeUnit;
  
  import org.eclipse.jetty.io.ArrayByteBufferPool;
  import org.eclipse.jetty.io.ByteBufferPool;
  import org.eclipse.jetty.io.Connection;
  import org.eclipse.jetty.io.ssl.SslConnection;
  import org.eclipse.jetty.util.FutureCallback;
  import org.eclipse.jetty.util.annotation.ManagedAttribute;
  import org.eclipse.jetty.util.annotation.ManagedObject;
  import org.eclipse.jetty.util.component.ContainerLifeCycle;
  import org.eclipse.jetty.util.component.Dumpable;
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.log.Logger;
  import org.eclipse.jetty.util.ssl.SslContextFactory;
  import org.eclipse.jetty.util.thread.Scheduler;
  import org.eclipse.jetty.util.thread.TimerScheduler;
  
  /**
   * <p>An abstract implementation of {@link Connector} that provides a {@link ConnectionFactory} mechanism
   * for creating {@link Connection} instances for various protocols (HTTP, SSL, SPDY, etc).</p>
   *
   * <h2>Connector Services</h2>
   * The abstract connector manages the dependent services needed by all specific connector instances:
   * <ul>
   * <li>The {@link Executor} service is used to run all active tasks needed by this connector such as accepting connections
   * or handle HTTP requests. The default is to use the {@link Server#getThreadPool()} as an executor.
   * </li>
   * <li>The {@link Scheduler} service is used to monitor the idle timeouts of all connections and is also made available
   * to the connections to time such things as asynchronous request timeouts.  The default is to use a new
   * {@link TimerScheduler} instance.
   * </li>
   * <li>The {@link ByteBufferPool} service is made available to all connections to be used to acquire and release
   * {@link ByteBuffer} instances from a pool.  The default is to use a new {@link ArrayByteBufferPool} instance.
   * </li>
   * </ul>
   * These services are managed as aggregate beans by the {@link ContainerLifeCycle} super class and
   * may either be managed or unmanaged beans.
   *
   * <h2>Connection Factories</h2>
   * The connector keeps a collection of {@link ConnectionFactory} instances, each of which are known by their
   * protocol name.  The protocol name may be a real protocol (eg http/1.1 or spdy/3) or it may be a private name
   * that represents a special connection factory. For example, the name "SSL-http/1.1" is used for
   * an {@link SslConnectionFactory} that has been instantiated with the {@link HttpConnectionFactory} as it's
   * next protocol.
   *
   * <h4>Configuring Connection Factories</h4>
   * The collection of available {@link ConnectionFactory} may be constructor injected or modified with the
   * methods {@link #addConnectionFactory(ConnectionFactory)}, {@link #removeConnectionFactory(String)} and
   * {@link #setConnectionFactories(Collection)}.  Only a single {@link ConnectionFactory} instance may be configured
   * per protocol name, so if two factories with the same {@link ConnectionFactory#getProtocol()} are set, then
   * the second will replace the first.
   * <p>
   * The protocol factory used for newly accepted connections is specified by
   * the method {@link #setDefaultProtocol(String)} or defaults to the protocol of the first configured factory.
   * <p>
   * Each Connection factory type is responsible for the configuration of the protocols that it accepts. Thus to
   * configure the HTTP protocol, you pass a {@link HttpConfiguration} instance to the {@link HttpConnectionFactory}
   * (or the SPDY factories that can also provide HTTP Semantics).  Similarly the {@link SslConnectionFactory} is
   * configured by passing it a {@link SslContextFactory} and a next protocol name.
   *
   * <h4>Connection Factory Operation</h4>
   * {@link ConnectionFactory}s may simply create a {@link Connection} instance to support a specific
   * protocol.  For example, the {@link HttpConnectionFactory} will create a {@link HttpConnection} instance
   * that can handle http/1.1, http/1.0 and http/0.9.
   * <p>
   * {@link ConnectionFactory}s may also create a chain of {@link Connection} instances, using other {@link ConnectionFactory} instances.
   * For example, the {@link SslConnectionFactory} is configured with a next protocol name, so that once it has accepted
  * a connection and created an {@link SslConnection}, it then used the next {@link ConnectionFactory} from the
  * connector using the {@link #getConnectionFactory(String)} method, to create a {@link Connection} instance that
  * will handle the unecrypted bytes from the {@link SslConnection}.   If the next protocol is "http/1.1", then the
  * {@link SslConnectionFactory} will have a protocol name of "SSL-http/1.1" and lookup "http/1.1" for the protocol
  * to run over the SSL connection.
  * <p>
  * {@link ConnectionFactory}s may also create temporary {@link Connection} instances that will exchange bytes
  * over the connection to determine what is the next protocol to use.  For example the NPN protocol is an extension
  * of SSL to allow a protocol to be specified during the SSL handshake. NPN is used by the SPDY protocol to
  * negotiate the version of SPDY or HTTP that the client and server will speak.  Thus to accept a SPDY connection, the
  * connector will be configured with {@link ConnectionFactory}s for "SSL-NPN", "NPN", "spdy/3", "spdy/2", "http/1.1"
  * with the default protocol being "SSL-NPN".  Thus a newly accepted connection uses "SSL-NPN", which specifies a
  * SSLConnectionFactory with "NPN" as the next protocol.  Thus an SslConnection instance is created chained to an NPNConnection
  * instance.  The NPN connection then negotiates with the client to determined the next protocol, which could be
  * "spdy/3", "spdy/2" or the default of "http/1.1".  Once the next protocol is determined, the NPN connection
  * calls {@link #getConnectionFactory(String)} to create a connection instance that will replace the NPN connection as
  * the connection chained to the SSLConnection.
  * <p>
  * <h2>Acceptors</h2>
  * The connector will execute a number of acceptor tasks to the {@link Exception} service passed to the constructor.
  * The acceptor tasks run in a loop while the connector is running and repeatedly call the abstract {@link #accept(int)} method.
  * The implementation of the accept method must:
  * <nl>
  * <li>block waiting for new connections
  * <li>accept the connection (eg socket accept)
  * <li>perform any configuration of the connection (eg. socket linger times)
  * <li>call the {@link #getDefaultConnectionFactory()} {@link ConnectionFactory#newConnection(Connector, org.eclipse.jetty.io.EndPoint)}
  * method to create a new Connection instance.
  * </nl>
  * The default number of acceptor tasks is the minimum of 1 and half the number of available CPUs. Having more acceptors may reduce
  * the latency for servers that see a high rate of new connections (eg HTTP/1.0 without keep-alive).  Typically the default is
  * sufficient for modern persistent protocols (HTTP/1.1, SPDY etc.)
  */
 @ManagedObject("Abstract implementation of the Connector Interface")
 public abstract class AbstractConnector extends ContainerLifeCycle implements Connector, Dumpable
 {
     protected final Logger LOG = Log.getLogger(getClass());
     // Order is important on server side, so we use a LinkedHashMap
     private final Map<String, ConnectionFactory> _factories = new LinkedHashMap<>();
     private final Server _server;
     private final Executor _executor;
     private final Scheduler _scheduler;
     private final ByteBufferPool _byteBufferPool;
     private final Thread[] _acceptors;
     private volatile CountDownLatch _stopping;
     private long _idleTimeout = 30000;
     private String _defaultProtocol;
     private ConnectionFactory _defaultConnectionFactory;
 
     /**
      * @param server The server this connector will be added to. Must not be null.
      * @param executor An executor for this connector or null to use the servers executor
      * @param scheduler A scheduler for this connector or null to a new {@link TimerScheduler} instance.
      * @param pool A buffer pool for this connector or null to use a default {@link ByteBufferPool}
      * @param acceptors the number of acceptor threads to use, or 0 for a default value.
      * @param factories The Connection Factories to use.
      */
     public AbstractConnector(
             Server server,
             Executor executor,
             Scheduler scheduler,
             ByteBufferPool pool,
             int acceptors,
             ConnectionFactory... factories)
     {
         _server=server;
         _executor=executor!=null?executor:_server.getThreadPool();
         _scheduler=scheduler!=null?scheduler:new TimerScheduler();
         _byteBufferPool = pool!=null?pool:new ArrayByteBufferPool();
 
         addBean(_server,false);
         addBean(_executor);
         if (executor==null)
             unmanage(_executor); // inherited from server
         addBean(_scheduler);
         addBean(_byteBufferPool);
 
         for (ConnectionFactory factory:factories)
             addConnectionFactory(factory);
 
         if (acceptors<=0)
             acceptors=Math.max(1,(Runtime.getRuntime().availableProcessors()) / 2);
         if (acceptors > 2 * Runtime.getRuntime().availableProcessors())
             LOG.warn("Acceptors should be <= 2*availableProcessors: " + this);
         _acceptors = new Thread[acceptors];
     }
 
 
     @Override
     public Server getServer()
     {
         return _server;
     }
 
     @Override
     public Executor getExecutor()
     {
         return _executor;
     }
 
     @Override
     public ByteBufferPool getByteBufferPool()
     {
         return _byteBufferPool;
     }
 
     @Override
     @ManagedAttribute("Idle timeout")
     public long getIdleTimeout()
     {
         return _idleTimeout;
     }
 
     /**
      * <p>Sets the maximum Idle time for a connection, which roughly translates to the {@link Socket#setSoTimeout(int)}
      * call, although with NIO implementations other mechanisms may be used to implement the timeout.</p>
      * <p>The max idle time is applied:</p>
      * <ul>
      * <li>When waiting for a new message to be received on a connection</li>
      * <li>When waiting for a new message to be sent on a connection</li>
      * </ul>
      * <p>This value is interpreted as the maximum time between some progress being made on the connection.
      * So if a single byte is read or written, then the timeout is reset.</p>
      *
      * @param idleTimeout the idle timeout
      */
     public void setIdleTimeout(long idleTimeout)
     {
         _idleTimeout = idleTimeout;
     }
 
     /**
      * @return Returns the number of acceptor threads.
      */
     @ManagedAttribute("number of acceptor threads")
     public int getAcceptors()
     {
         return _acceptors.length;
     }
 
     @Override
     protected void doStart() throws Exception
     {
         _defaultConnectionFactory = getConnectionFactory(_defaultProtocol);
         if(_defaultConnectionFactory==null)
             throw new IllegalStateException("No protocol factory for default protocol: "+_defaultProtocol);
 
         super.doStart();
 
         _stopping=new CountDownLatch(_acceptors.length);
         for (int i = 0; i < _acceptors.length; i++)
             getExecutor().execute(new Acceptor(i));
 
         LOG.info("Started {}", this);
     }
 
 
     protected void interruptAcceptors()
     {
         for (Thread thread : _acceptors)
         {
             if (thread != null)
                 thread.interrupt();
         }
     }
 
     @Override
     public Future<Void> shutdown()
     {
         return new FutureCallback(true);
     }
 
     @Override
     protected void doStop() throws Exception
     {
         // Tell the acceptors we are stopping
         interruptAcceptors();
 
         // If we have a stop timeout
         long stopTimeout = getStopTimeout();
         if (stopTimeout > 0 && _stopping!=null)
             _stopping.await(stopTimeout,TimeUnit.MILLISECONDS);
         _stopping=null;
 
         super.doStop();
 
         LOG.info("Stopped {}", this);
     }
 
     public void join() throws InterruptedException
     {
         join(0);
     }
 
     public void join(long timeout) throws InterruptedException
     {
         for (Thread thread : _acceptors)
             if (thread != null)
                 thread.join(timeout);
     }
 
     protected abstract void accept(int acceptorID) throws IOException, InterruptedException;
 
 
     /* ------------------------------------------------------------ */
     /**
      * @return Is the connector accepting new connections
      */
     protected boolean isAccepting()
     {
         return isRunning();
     }
 
     @Override
     public ConnectionFactory getConnectionFactory(String protocol)
     {
         synchronized (_factories)
         {
             return _factories.get(protocol.toLowerCase(Locale.ENGLISH));
         }
     }
 
     @Override
     public <T> T getConnectionFactory(Class<T> factoryType)
     {
         synchronized (_factories)
         {
             for (ConnectionFactory f : _factories.values())
                 if (factoryType.isAssignableFrom(f.getClass()))
                     return (T)f;
             return null;
         }
     }
 
     public void addConnectionFactory(ConnectionFactory factory)
     {
         synchronized (_factories)
         {
             ConnectionFactory old=_factories.remove(factory.getProtocol());
             if (old!=null)
                 removeBean(old);
             _factories.put(factory.getProtocol().toLowerCase(Locale.ENGLISH), factory);
             addBean(factory);
             if (_defaultProtocol==null)
                 _defaultProtocol=factory.getProtocol();
         }
     }
 
     public ConnectionFactory removeConnectionFactory(String protocol)
     {
         synchronized (_factories)
         {
             ConnectionFactory factory= _factories.remove(protocol.toLowerCase(Locale.ENGLISH));
             removeBean(factory);
             return factory;
         }
     }
 
     @Override
     public Collection<ConnectionFactory> getConnectionFactories()
     {
         synchronized (_factories)
         {
             return _factories.values();
         }
     }
 
     public void setConnectionFactories(Collection<ConnectionFactory> factories)
     {
         synchronized (_factories)
         {
             List<ConnectionFactory> existing = new ArrayList<>(_factories.values());
             for (ConnectionFactory factory: existing)
                 removeConnectionFactory(factory.getProtocol());
             for (ConnectionFactory factory: factories)
                 if (factory!=null)
                     addConnectionFactory(factory);
         }
     }
 
 
     @Override
     @ManagedAttribute("Protocols supported by this connector")
     public List<String> getProtocols()
     {
         synchronized (_factories)
         {
             return new ArrayList<>(_factories.keySet());
         }
     }
 
     public void clearConnectionFactories()
     {
         synchronized (_factories)
         {
             _factories.clear();
         }
     }
 
     @ManagedAttribute("This connector's default protocol")
     public String getDefaultProtocol()
     {
         return _defaultProtocol;
     }
 
     public void setDefaultProtocol(String defaultProtocol)
     {
         _defaultProtocol = defaultProtocol.toLowerCase(Locale.ENGLISH);
         if (isRunning())
             _defaultConnectionFactory=getConnectionFactory(_defaultProtocol);
     }
 
     @Override
     public ConnectionFactory getDefaultConnectionFactory()
     {
         if (isStarted())
             return _defaultConnectionFactory;
         return getConnectionFactory(_defaultProtocol);
     }
 
     private class Acceptor implements Runnable
     {
         private final int _acceptor;
 
         private Acceptor(int id)
         {
             _acceptor = id;
         }
 
         @Override
         public void run()
         {
             Thread current = Thread.currentThread();
             String name = current.getName();
             current.setName(name + "-acceptor-" + _acceptor + "-" + AbstractConnector.this);
 
             synchronized (AbstractConnector.this)
             {
                 _acceptors[_acceptor] = current;
             }
 
             try
             {
                 while (isAccepting())
                 {
                     try
                     {
                         accept(_acceptor);
                     }
                     catch (Throwable e)
                     {
                         if (isAccepting())
                             LOG.warn(e);
                         else
                             LOG.debug(e);
                     }
                 }
             }
             finally
             {
                 current.setName(name);
 
                 synchronized (AbstractConnector.this)
                 {
                     _acceptors[_acceptor] = null;
                 }
                 _stopping.countDown();
             }
         }
     }
 
 //    protected void connectionOpened(Connection connection)
 //    {
 //        _stats.connectionOpened();
 //        connection.onOpen();
 //    }
 //
 //    protected void connectionClosed(Connection connection)
 //    {
 //        connection.onClose();
 //        long duration = System.currentTimeMillis() - connection.getEndPoint().getCreatedTimeStamp();
 //        _stats.connectionClosed(duration, connection.getMessagesIn(), connection.getMessagesOut());
 //    }
 //
 //    public void connectionUpgraded(Connection oldConnection, Connection newConnection)
 //    {
 //        oldConnection.onClose();
 //        _stats.connectionUpgraded(oldConnection.getMessagesIn(), oldConnection.getMessagesOut());
 //        newConnection.onOpen();
 //    }
 
     @Override
     public Scheduler getScheduler()
     {
         return _scheduler;
     }
 
     @Override
     public String toString()
     {
         return String.format("%s@%x{%s}",
                 getClass().getSimpleName(),
                 hashCode(),
                 getDefaultProtocol());
     }
 }