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 java.net.http;

    27 

    28 import java.nio.ByteBuffer;

    29 import java.util.LinkedList;

    30 import java.util.List;

    31 

    32 /**

    33  * Represents one frame. May be initialized with a leftover buffer from previous

    34  * frame. Call {@code haveFrame()} to determine if buffers contains at least one

    35  * frame. If false, the obtain another buffer and call {@code}input(ByteBuffer)}.

    36  * There may be additional bytes at end of the frame list.

    37  */

    38 class FrameReader {

    39 

    40     final List<ByteBuffer> buffers;

    41 

    42     FrameReader() {

    43         buffers = new LinkedList<>();

    44     }

    45 

    46     FrameReader(FrameReader that) {

    47         this.buffers = that.buffers;

    48     }

    49 

    50     FrameReader(ByteBuffer remainder) {

    51         buffers = new LinkedList<>();

    52         if (remainder != null) {

    53             buffers.add(remainder);

    54         }

    55     }

    56 

    57     public synchronized void input(ByteBuffer buffer) {

    58         buffers.add(buffer);

    59     }

    60 

    61     public synchronized boolean haveFrame() {

    62         //buffers = Utils.superCompact(buffers, () -> ByteBuffer.allocate(Utils.BUFSIZE));

    63         int size = 0;

    64         for (ByteBuffer buffer : buffers) {

    65             size += buffer.remaining();

    66         }

    67         if (size < 3) {

    68             return false; // don't have length yet

    69         }

    70         // we at least have length field

    71         int length = 0;

    72         int j = 0;

    73         ByteBuffer b = buffers.get(j);

    74         b.mark();

    75         for (int i=0; i<3; i++) {

    76             while (!b.hasRemaining()) {

    77                 b.reset();

    78                 b = buffers.get(++j);

    79                 b.mark();

    80             }

    81             length = (length << 8) + (b.get() & 0xff);

    82         }

    83         b.reset();

    84         return (size >= length + 9); // frame length

    85     }

    86 

    87     synchronized List<ByteBuffer> frame() {

    88         return buffers;

    89     }

    90 }