1 /*
   2  * Copyright (c) 2015, 2016, 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  */
  24 package java.net.http;
  25 
  26 import java.nio.ByteBuffer;
  27 import java.util.function.Consumer;
  28 
  29 /**
  30  * Implemented by classes that offer an asynchronous interface.
  31  *
  32  * PlainHttpConnection, AsyncSSLConnection AsyncSSLDelegate.
  33  *
  34  * setAsyncCallbacks() is called to set the callback for reading
  35  * and error notification. Reads all happen on the selector thread, which
  36  * must not block.
  37  *
  38  * Writing uses the same write() methods as used in blocking mode.
  39  * Queues are employed on the writing side to buffer data while it is waiting
  40  * to be sent. This strategy relies on HTTP/2 protocol flow control to stop
  41  * outgoing queue from continually growing. Writes can be initiated by the
  42  * calling thread, but if socket becomes full then the queue is emptied by
  43  * the selector thread
  44  *
  45  */
  46 interface AsyncConnection {
  47 
  48     /**
  49      * Enables asynchronous sending and receiving mode. The given async
  50      * receiver will receive all incoming data. asyncInput() will be called
  51      * to trigger reads. asyncOutput() will be called to drive writes.
  52      *
  53      * The errorReceiver callback must be called when any fatal exception
  54      * occurs. Connection is assumed to be closed afterwards.
  55      *
  56      * @param asyncReceiver
  57      * @param errorReceiver
  58      */
  59     void setAsyncCallbacks(
  60             Consumer<ByteBuffer> asyncReceiver,
  61             Consumer<Throwable> errorReceiver);
  62 
  63     /**
  64      * Does whatever is required to start reading. Usually registers
  65      * an event with the selector thread.
  66      */
  67     void startReading();
  68 }