1 /*
   2  * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.incubator.http.internal.websocket;
  27 
  28 import java.io.IOException;
  29 
  30 /*
  31  * Abstracts out I/O channel for the WebSocket implementation. The latter then
  32  * deals with input and output streams of messages and does not have to
  33  * understand the state machine of channels (e.g. how exactly they are closed).
  34  * Mocking this type will allow testing WebSocket message exchange in isolation.
  35  */
  36 public class TransportSupplier {
  37 
  38     protected final RawChannel channel; /* Exposed for testing purposes */
  39     private final Object lock = new Object();
  40     private Transmitter transmitter;
  41     private Receiver receiver;
  42     private boolean receiverShutdown;
  43     private boolean transmitterShutdown;
  44     private boolean closed;
  45 
  46     public TransportSupplier(RawChannel channel) {
  47         this.channel = channel;
  48     }
  49 
  50     public Receiver receiver(MessageStreamConsumer consumer) {
  51         synchronized (lock) {
  52             if (receiver == null) {
  53                 receiver = newReceiver(consumer);
  54             }
  55             return receiver;
  56         }
  57     }
  58 
  59     public Transmitter transmitter() {
  60         synchronized (lock) {
  61             if (transmitter == null) {
  62                 transmitter = newTransmitter();
  63             }
  64             return transmitter;
  65         }
  66     }
  67 
  68     protected Receiver newReceiver(MessageStreamConsumer consumer) {
  69         return new Receiver(consumer, channel) {
  70             @Override
  71             public void close() throws IOException {
  72                 synchronized (lock) {
  73                     if (!closed) {
  74                         try {
  75                             super.close();
  76                         } finally {
  77                             receiverShutdown = true;
  78                             if (transmitterShutdown) {
  79                                 closed = true;
  80                                 channel.close();
  81                             }
  82                         }
  83                     }
  84                 }
  85             }
  86         };
  87     }
  88 
  89     protected Transmitter newTransmitter() {
  90         return new Transmitter(channel) {
  91             @Override
  92             public void close() throws IOException {
  93                 synchronized (lock) {
  94                     if (!closed) {
  95                         try {
  96                             super.close();
  97                         } finally {
  98                             transmitterShutdown = true;
  99                             if (receiverShutdown) {
 100                                 closed = true;
 101                                 channel.close();
 102                             }
 103                         }
 104                     }
 105                 }
 106             }
 107         };
 108     }
 109 }