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    1   /*
    2    *  Licensed to the Apache Software Foundation (ASF) under one
    3    *  or more contributor license agreements.  See the NOTICE file
    4    *  distributed with this work for additional information
    5    *  regarding copyright ownership.  The ASF licenses this file
    6    *  to you under the Apache License, Version 2.0 (the
    7    *  "License"); you may not use this file except in compliance
    8    *  with the License.  You may obtain a copy of the License at
    9    *
    10   *    http://www.apache.org/licenses/LICENSE-2.0
    11   *
    12   *  Unless required by applicable law or agreed to in writing,
    13   *  software distributed under the License is distributed on an
    14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    15   *  KIND, either express or implied.  See the License for the
    16   *  specific language governing permissions and limitations
    17   *  under the License.
    18   *
    19   */
    20  package org.apache.mina.proxy.event;
    21
    22  import java.util.LinkedList;
    23  import java.util.Queue;
    24
    25  import org.apache.mina.proxy.handlers.socks.SocksProxyRequest;
    26  import org.apache.mina.proxy.session.ProxyIoSession;
    27  import org.slf4j.Logger;
    28  import org.slf4j.LoggerFactory;
    29
    30  /**
    31   * IoSessionEventQueue.java - Queue that contains filtered session events
    32   * while handshake isn't done.
    33   *
    34   * @author <a href="http://mina.apache.org">Apache MINA Project</a>
    35   * @since MINA 2.0.0-M3
    36   */
    37  public class IoSessionEventQueue {
    38      private final static Logger logger = LoggerFactory.getLogger(IoSessionEventQueue.class);
    39
    40      /**
    41       * The proxy session object.
    42       */
    43      private ProxyIoSession proxyIoSession;
    44
    45      /**
    46       * Queue of session events which occurred before the proxy handshake had completed.
    47       */
    48      private Queue<IoSessionEvent> sessionEventsQueue = new LinkedList<IoSessionEvent>();
    49
    50      public IoSessionEventQueue(ProxyIoSession proxyIoSession) {
    51          this.proxyIoSession = proxyIoSession;
    52      }
    53
    54      /**
    55       * Discard all events from the queue.
    56       */
    57      private void discardSessionQueueEvents() {
    58          synchronized (sessionEventsQueue) {
    59              // Free queue
    60              sessionEventsQueue.clear();
    61              logger.debug("Event queue CLEARED");
    62          }
    63      }
    64
    65      /**
    66       * Event is enqueued only if necessary :
    67       * - socks proxies do not need the reconnection feature so events are always
    68       * forwarded for these.
    69       * - http proxies events will be enqueued while handshake has not been completed
    70       * or until connection was closed.
    71       * If connection was prematurely closed previous events are discarded and only the
    72       * session closed is delivered.
    73       *
    74       * @param evt the event to enqueue
    75       */
    76      public void enqueueEventIfNecessary(final IoSessionEvent evt) {
    77          logger.debug("??? >> Enqueue {}", evt);
    78
    79          if (proxyIoSession.getRequest() instanceof SocksProxyRequest) {
    80              // No reconnection used
    81              evt.deliverEvent();
    82              return;
    83          }
    84
    85          if (proxyIoSession.getHandler().isHandshakeComplete()) {
    86              evt.deliverEvent();
    87          } else {
    88              if (evt.getType() == IoSessionEventType.CLOSED) {
    89                  if (proxyIoSession.isAuthenticationFailed()) {
    90                      proxyIoSession.getConnector().cancelConnectFuture();
    91                      discardSessionQueueEvents();
    92                      evt.deliverEvent();
    93                  } else {
    94                      discardSessionQueueEvents();
    95                  }
    96              } else if (evt.getType() == IoSessionEventType.OPENED) {
    97                  // Enqueue event cause it will not reach IoHandler but deliver it to enable
    98                  // session creation.
    99                  enqueueSessionEvent(evt);
    100                 evt.deliverEvent();
    101             } else {
    102                 enqueueSessionEvent(evt);
    103             }
    104         }
    105     }
    106
    107     /**
    108      * Send any session event which were queued while waiting for handshaking to complete.
    109      *
    110      * Please note this is an internal method. DO NOT USE it in your code.
    111      */
    112     public void flushPendingSessionEvents() throws Exception {
    113         synchronized (sessionEventsQueue) {
    114             IoSessionEvent evt;
    115
    116             while ((evt = sessionEventsQueue.poll()) != null) {
    117                 logger.debug(" Flushing buffered event: {}", evt);
    118                 evt.deliverEvent();
    119             }
    120         }
    121     }
    122
    123     /**
    124      * Enqueue an event to be delivered once handshaking is complete.
    125      *
    126      * @param evt the session event to enqueue
    127      */
    128     private void enqueueSessionEvent(final IoSessionEvent evt) {
    129         synchronized (sessionEventsQueue) {
    130             logger.debug("Enqueuing event: {}", evt);
    131             sessionEventsQueue.offer(evt);
    132         }
    133     }
    134 }