1 /*
   2  * Copyright (c) 2015, 2020, 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.internal.net.http.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         void closeRawChannel() throws IOException;
  44     }
  45 
  46     interface RawEvent {
  47 
  48         /*
  49          * Returns the selector op flags this event is interested in.
  50          */
  51         int interestOps();
  52 
  53         /*
  54          * Called when event occurs.
  55          */
  56         void handle();
  57     }
  58 
  59     /*
  60      * Registers given event whose callback will be called once only (i.e.
  61      * register new event for each callback).
  62      *
  63      * Memory consistency effects: actions in a thread calling registerEvent
  64      * happen-before any subsequent actions in the thread calling event.handle
  65      */
  66     void registerEvent(RawEvent event) throws IOException;
  67 
  68     /**
  69      * Hands over the initial bytes. Once the bytes have been returned they are
  70      * no longer available and the method will throw an {@link
  71      * IllegalStateException} on each subsequent invocation.
  72      *
  73      * @return the initial bytes
  74      * @throws IllegalStateException
  75      *         if the method has been already invoked
  76      */
  77     ByteBuffer initialByteBuffer() throws IllegalStateException;
  78 
  79     /*
  80      * Returns a ByteBuffer with the data read or null if EOF is reached. Has no
  81      * remaining bytes if no data available at the moment.
  82      */
  83     ByteBuffer read() throws IOException;
  84 
  85     /*
  86      * Writes a sequence of bytes to this channel from a subsequence of the
  87      * given buffers.
  88      */
  89     long write(ByteBuffer[] srcs, int offset, int length) throws IOException;
  90 
  91     /**
  92      * Shutdown the connection for reading without closing the channel.
  93      *
  94      * <p> Once shutdown for reading then further reads on the channel will
  95      * return {@code null}, the end-of-stream indication. If the input side of
  96      * the connection is already shutdown then invoking this method has no
  97      * effect.
  98      *
  99      * @throws ClosedChannelException
 100      *         If this channel is closed
 101      * @throws IOException
 102      *         If some other I/O error occurs
 103      */
 104     void shutdownInput() throws IOException;
 105 
 106     /**
 107      * Shutdown the connection for writing without closing the channel.
 108      *
 109      * <p> Once shutdown for writing then further attempts to write to the
 110      * channel will throw {@link ClosedChannelException}. If the output side of
 111      * the connection is already shutdown then invoking this method has no
 112      * effect.
 113      *
 114      * @throws ClosedChannelException
 115      *         If this channel is closed
 116      * @throws IOException
 117      *         If some other I/O error occurs
 118      */
 119     void shutdownOutput() throws IOException;
 120 
 121     /**
 122      * Closes this channel.
 123      *
 124      * @throws IOException
 125      *         If an I/O error occurs
 126      */
 127     @Override
 128     void close() throws IOException;
 129 }