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.ftp.core.data.handler;
21
22 import io.netty.buffer.ByteBuf;
23
24 /**
25 * SeekAheadData Class used to optimize access to the incoming buffer
26 */
27 class FtpSeekAheadData {
28 /**
29 * Exception when NO Backend Array is found
30 */
31 static class SeekAheadNoBackArrayException extends Exception {
32 private static final long serialVersionUID = -630418804938699495L;
33 }
34
35 byte[] bytes;
36
37 int readerIndex;
38
39 int pos;
40
41 int limit;
42
43 ByteBuf buffer;
44
45 /**
46 * @param buffer
47 */
48 FtpSeekAheadData(final ByteBuf buffer) throws SeekAheadNoBackArrayException {
49 if (!buffer.hasArray()) {
50 throw new SeekAheadNoBackArrayException();
51 }
52 this.buffer = buffer;
53 bytes = buffer.array();
54 pos = readerIndex = buffer.arrayOffset() + buffer.readerIndex();
55 limit = buffer.arrayOffset() + buffer.writerIndex();
56 }
57
58 /**
59 * @param minus this value will be used as (currentPos - minus) to
60 * set the
61 * current readerIndex in the buffer.
62 */
63 void setReadPosition(final int minus) {
64 pos -= minus;
65 readerIndex = pos;
66 buffer.readerIndex(readerIndex);
67 }
68
69 void clear() {
70 buffer = null;
71 bytes = null;
72 limit = 0;
73 pos = 0;
74 readerIndex = 0;
75 }
76 }