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.io.IOException;

    27 import java.nio.ByteBuffer;

    28 

    29 /**

    30  * When sending a frame, the length field must be set in sub-class

    31  * by calling computeLength()

    32  */

    33 abstract class Http2Frame {

    34 

    35     int length = -1;

    36     int type;

    37     int streamid;

    38     int flags;

    39 

    40     // called when reading in only

    41     void initCommon(int length, int type, int streamid, int flags) {

    42         this.length = length;

    43         this.type = type;

    44         this.streamid = streamid;

    45         this.flags = flags;

    46     }

    47 

    48     public int length() {

    49         return length;

    50     }

    51 

    52     public int type() {

    53         return type;

    54     }

    55 

    56     public int streamid() {

    57         return streamid;

    58     }

    59 

    60     public void setFlag(int flag) {

    61         flags |= flag;

    62     }

    63 

    64     public void setFlags(int flags) {

    65         this.flags = flags;

    66     }

    67 

    68     public int getFlags() {

    69         return flags;

    70     }

    71 

    72     public boolean getFlag(int flag) {

    73         return (flags & flag) != 0;

    74     }

    75 

    76     public void clearFlag(int flag) {

    77         flags &= 0xffffffff ^ flag;

    78     }

    79 

    80     public void streamid(int streamid) {

    81         this.streamid = streamid;

    82     }

    83 

    84     abstract void readIncomingImpl(ByteBufferConsumer bc) throws IOException;

    85 

    86     /**

    87      * assume given array contains at least one complete frame.

    88      */

    89     static Http2Frame readIncoming(ByteBufferConsumer bc) throws IOException {

    90         int x = bc.getInt();

    91         int length = x >> 8;

    92         int type = x & 0xff;

    93         int flags = bc.getByte();

    94         int streamid = bc.getInt();

    95         Http2Frame f = null;

    96         switch (type) {

    97           case DataFrame.TYPE:

    98             f = new DataFrame();

    99             break;

   100           case HeadersFrame.TYPE:

   101             f = new HeadersFrame();

   102             break;

   103           case ContinuationFrame.TYPE:

   104             f = new ContinuationFrame();

   105             break;

   106           case ResetFrame.TYPE:

   107             f = new ResetFrame();

   108             break;

   109           case PriorityFrame.TYPE:

   110             f = new PriorityFrame();

   111             break;

   112           case SettingsFrame.TYPE:

   113             f = new SettingsFrame();

   114             break;

   115           case GoAwayFrame.TYPE:

   116             f = new GoAwayFrame();

   117             break;

   118           case PingFrame.TYPE:

   119             f = new PingFrame();

   120             break;

   121           case PushPromiseFrame.TYPE:

   122             f = new PushPromiseFrame();

   123             break;

   124           case WindowUpdateFrame.TYPE:

   125             f = new WindowUpdateFrame();

   126             break;

   127           default:

   128             String msg = Integer.toString(type);

   129             throw new IOException("unknown frame type " + msg);

   130         }

   131         f.initCommon(length, type, streamid, flags);

   132         f.readIncomingImpl(bc);

   133         return f;

   134     }

   135 

   136     public String typeAsString() {

   137         return asString(this.type);

   138     }

   139 

   140     public static String asString(int type) {

   141         switch (type) {

   142           case DataFrame.TYPE:

   143             return "DATA";

   144           case HeadersFrame.TYPE:

   145             return "HEADERS";

   146           case ContinuationFrame.TYPE:

   147             return "CONTINUATION";

   148           case ResetFrame.TYPE:

   149             return "RESET";

   150           case PriorityFrame.TYPE:

   151             return "PRIORITY";

   152           case SettingsFrame.TYPE:

   153             return "SETTINGS";

   154           case GoAwayFrame.TYPE:

   155             return "GOAWAY";

   156           case PingFrame.TYPE:

   157             return "PING";

   158           case PushPromiseFrame.TYPE:

   159             return "PUSH_PROMISE";

   160           case WindowUpdateFrame.TYPE:

   161             return "WINDOW_UPDATE";

   162           default:

   163             return "UNKNOWN";

   164         }

   165     }

   166 

   167     @Override

   168     public String toString() {

   169         StringBuilder sb = new StringBuilder();

   170         sb.append(typeAsString())

   171                 .append(": length=")

   172                 .append(Integer.toString(length))

   173                 .append(", streamid=")

   174                 .append(streamid)

   175                 .append(", flags=");

   176 

   177         int f = flags;

   178         int i = 0;

   179         if (f == 0) {

   180             sb.append("0 ");

   181         } else {

   182             while (f != 0) {

   183                 if ((f & 1) == 1) {

   184                     sb.append(flagAsString(1 << i))

   185                       .append(' ');

   186                 }

   187                 f = f >> 1;

   188                 i++;

   189             }

   190         }

   191         return sb.toString();

   192     }

   193 

   194     // Override

   195     String flagAsString(int f) {

   196         return "unknown";

   197     }

   198 

   199     abstract void computeLength();

   200 

   201     void writeOutgoing(ByteBufferGenerator bg) {

   202         if (length == -1) {

   203             throw new InternalError("Length not set on outgoing frame");

   204         }

   205         ByteBuffer buf = bg.getBuffer(9);

   206         int x = (length << 8) + type;

   207         buf.putInt(x);

   208         buf.put((byte)flags);

   209         buf.putInt(streamid);

   210     }

   211 }