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  * questions.
  24  */
  25 
  26 package jdk.incubator.http.internal.websocket;
  27 
  28 import java.io.Closeable;
  29 import java.io.IOException;
  30 import java.nio.ByteBuffer;
  31 import java.nio.channels.ClosedChannelException;
  32 
  33 /*
  34  * I/O abstraction used to implement WebSocket.
  35  *
  36  * @since 9
  37  */
  38 public interface RawChannel extends Closeable {
  39 
  40     interface Provider {
  41 
  42         RawChannel rawChannel() throws IOException;
  43     }
  44 
  45     interface RawEvent {
  46 
  47         /*
  48          * Returns the selector op flags this event is interested in.
  49          */
  50         int interestOps();
  51 
  52         /*
  53          * Called when event occurs.
  54          */
  55         void handle();
  56     }
  57 
  58     /*
  59      * Registers given event whose callback will be called once only (i.e.
  60      * register new event for each callback).
  61      *
  62      * Memory consistency effects: actions in a thread calling registerEvent
  63      * happen-before any subsequent actions in the thread calling event.handle
  64      */
  65     void registerEvent(RawEvent event) throws IOException;
  66 
  67     /**
  68      * Hands over the initial bytes. Once the bytes have been returned they are
  69      * no longer available and the method will throw an {@link
  70      * IllegalStateException} on each subsequent invocation.
  71      *
  72      * @return the initial bytes
  73      * @throws IllegalStateException
  74      *         if the method has been already invoked
  75      */
  76     ByteBuffer initialByteBuffer() throws IllegalStateException;
  77 
  78     /*
  79      * Returns a ByteBuffer with the data read or null if EOF is reached. Has no
  80      * remaining bytes if no data available at the moment.
  81      */
  82     ByteBuffer read() throws IOException;
  83 
  84     /*
  85      * Writes a sequence of bytes to this channel from a subsequence of the
  86      * given buffers.
  87      */
  88     long write(ByteBuffer[] srcs, int offset, int length) throws IOException;
  89 
  90     /**
  91      * Shutdown the connection for reading without closing the channel.
  92      *
  93      * <p> Once shutdown for reading then further reads on the channel will
  94      * return {@code null}, the end-of-stream indication. If the input side of
  95      * the connection is already shutdown then invoking this method has no
  96      * effect.
  97      *
  98      * @throws ClosedChannelException
  99      *         If this channel is closed
 100      * @throws IOException
 101      *         If some other I/O error occurs
 102      */
 103     void shutdownInput() throws IOException;
 104 
 105     /**
 106      * Shutdown the connection for writing without closing the channel.
 107      *
 108      * <p> Once shutdown for writing then further attempts to write to the
 109      * channel will throw {@link ClosedChannelException}. If the output side of
 110      * the connection is already shutdown then invoking this method has no
 111      * effect.
 112      *
 113      * @throws ClosedChannelException
 114      *         If this channel is closed
 115      * @throws IOException
 116      *         If some other I/O error occurs
 117      */
 118     void shutdownOutput() throws IOException;
 119 
 120     /**
 121      * Closes this channel.
 122      *
 123      * @throws IOException
 124      *         If an I/O error occurs
 125      */
 126     @Override
 127     void close() throws IOException;
 128 }