//
// ========================================================================
// Copyright (c) 1995-2014 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.client;
import java.io.IOException;
import java.util.Arrays;
import org.eclipse.jetty.client.api.Connection;
import org.eclipse.jetty.client.api.Request;
import org.eclipse.jetty.util.Promise;
import org.eclipse.jetty.util.component.ContainerLifeCycle;
public abstract class PoolingHttpDestination<C extends Connection> extends HttpDestination implements Promise<Connection>
{
private final ConnectionPool connectionPool;
public PoolingHttpDestination(HttpClient client, Origin origin)
{
super(client, origin);
this.connectionPool = newConnectionPool(client);
}
protected ConnectionPool newConnectionPool(HttpClient client)
{
return new ConnectionPool(this, client.getMaxConnectionsPerDestination(), this);
}
public ConnectionPool getConnectionPool()
{
return connectionPool;
}
@Override
@SuppressWarnings("unchecked")
public void succeeded(Connection connection)
{
process((C)connection, true);
}
@Override
public void failed(final Throwable x)
{
getHttpClient().getExecutor().execute(new Runnable()
{
@Override
public void run()
{
abort(x);
}
});
}
protected void send()
{
C connection = acquire();
if (connection != null)
process(connection, false);
}
@SuppressWarnings("unchecked")
public C acquire()
{
return (C)connectionPool.acquire();
}
/**
* <p>Processes a new connection making it idle or active depending on whether requests are waiting to be sent.</p>
* <p>A new connection is created when a request needs to be executed; it is possible that the request that
* triggered the request creation is executed by another connection that was just released, so the new connection
* may become idle.</p>
* <p>If a request is waiting to be executed, it will be dequeued and executed by the new connection.</p>
*
* @param connection the new connection
* @param dispatch whether to dispatch the processing to another thread
*/
public void process(final C connection, boolean dispatch)
{
HttpClient client = getHttpClient();
final HttpExchange exchange = getHttpExchanges().poll();
if (LOG.isDebugEnabled())
LOG.debug("Processing exchange {} on {} of {}", exchange, connection, this);
if (exchange == null)
{
if (!connectionPool.release(connection))
connection.close();
if (!client.isRunning())
{
if (LOG.isDebugEnabled())
LOG.debug("{} is stopping", client);
connection.close();
}
}
else
{
final Request request = exchange.getRequest();
Throwable cause = request.getAbortCause();
if (cause != null)
{
if (LOG.isDebugEnabled())
LOG.debug("Aborted before processing {}: {}", exchange, cause);
// It may happen that the request is aborted before the exchange
// is created. Aborting the exchange a second time will result in
// a no-operation, so we just abort here to cover that edge case.
exchange.abort(cause);
}
else
{
if (dispatch)
{
client.getExecutor().execute(new Runnable()
{
@Override
public void run()
{
send(connection, exchange);
}
});
}
else
{
send(connection, exchange);
}
}
}
}
protected abstract void send(C connection, HttpExchange exchange);
@Override
public void release(Connection c)
{
@SuppressWarnings("unchecked")
C connection = (C)c;
if (LOG.isDebugEnabled())
LOG.debug("{} released", connection);
HttpClient client = getHttpClient();
if (client.isRunning())
{
if (connectionPool.isActive(connection))
{
process(connection, false);
}
else
{
if (LOG.isDebugEnabled())
LOG.debug("{} explicit", connection);
}
}
else
{
if (LOG.isDebugEnabled())
LOG.debug("{} is stopped", client);
close(connection);
connection.close();
}
}
@Override
public void close(Connection oldConnection)
{
super.close(oldConnection);
connectionPool.remove(oldConnection);
if (getHttpExchanges().isEmpty())
{
if (getHttpClient().isRemoveIdleDestinations() && connectionPool.isEmpty())
{
// There is a race condition between this thread removing the destination
// and another thread queueing a request to this same destination.
// If this destination is removed, but the request queued, a new connection
// will be opened, the exchange will be executed and eventually the connection
// will idle timeout and be closed. Meanwhile a new destination will be created
// in HttpClient and will be used for other requests.
getHttpClient().removeDestination(this);
}
}
else
{
// We need to execute queued requests even if this connection failed.
// We may create a connection that is not needed, but it will eventually
// idle timeout, so no worries.
C newConnection = acquire();
if (newConnection != null)
process(newConnection, false);
}
}
public void close()
{
super.close();
connectionPool.close();
}
@Override
public void dump(Appendable out, String indent) throws IOException
{
ContainerLifeCycle.dump(out, indent, Arrays.asList(connectionPool));
}
@Override
public String toString()
{
return String.format("%s,pool=%s", super.toString(), connectionPool);
}
}