1 /*
2 * This file is part of Waarp Project (named also Waarp or GG).
3 *
4 * Copyright (c) 2019, Waarp SAS, and individual contributors by the @author
5 * tags. See the COPYRIGHT.txt in the distribution for a full listing of
6 * individual contributors.
7 *
8 * All Waarp Project is free software: you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation, either version 3 of the License, or (at your
11 * option) any later version.
12 *
13 * Waarp is distributed in the hope that it will be useful, but WITHOUT ANY
14 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
15 * A PARTICULAR PURPOSE. See the GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License along with
18 * Waarp . If not, see <http://www.gnu.org/licenses/>.
19 */
20 package org.waarp.openr66.protocol.localhandler.packet;
21
22 import io.netty.buffer.ByteBuf;
23 import org.waarp.openr66.protocol.exception.OpenR66ProtocolPacketException;
24
25 /**
26 * Local Packet Decoder
27 */
28 public class LocalPacketCodec {
29
30 public static AbstractLocalPacket decodeNetworkPacket(final ByteBuf buf)
31 throws OpenR66ProtocolPacketException {
32 // Mark the current buffer position
33 buf.markReaderIndex();
34 // Read the length field
35 final int length = buf.readInt();
36 if (buf.readableBytes() < length) {
37 buf.resetReaderIndex();
38 return null;
39 }
40 // Now we can read the header
41 // Header: Header length field (4 bytes) = Middle length field (4
42 // bytes), End length field (4 bytes), type field (1 byte), ...
43 final int middleLength = buf.readInt();
44 final int endLength = buf.readInt();
45 // check if the packet is complete
46 if (middleLength + endLength + length - 8 > buf.readableBytes()) {
47 buf.resetReaderIndex();
48 return null;
49 }
50 // createPacketFromByteBuf read the buffer
51 return LocalPacketFactory.createPacketFromByteBuf(length - 8, middleLength,
52 endLength, buf);
53 }
54
55 }