aboutsummaryrefslogtreecommitdiff
path: root/nxcomp/src/DecodeBuffer.h
blob: 038fbc83dc198e038c47aa6fe1630f4bc3a3e65b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
/**************************************************************************/
/*                                                                        */
/* Copyright (c) 2001, 2011 NoMachine (http://www.nomachine.com)          */
/* Copyright (c) 2008-2017 Oleksandr Shneyder <o.shneyder@phoca-gmbh.de>  */
/* Copyright (c) 2014-2022 Ulrich Sibiller <uli42@gmx.de>                 */
/* Copyright (c) 2014-2019 Mihai Moldovan <ionic@ionic.de>                */
/* Copyright (c) 2011-2022 Mike Gabriel <mike.gabriel@das-netzwerkteam.de>*/
/* Copyright (c) 2015-2016 Qindel Group (http://www.qindel.com)           */
/*                                                                        */
/* NXCOMP, NX protocol compression and NX extensions to this software     */
/* are copyright of the aforementioned persons and companies.             */
/*                                                                        */
/* Redistribution and use of the present software is allowed according    */
/* to terms specified in the file LICENSE.nxcomp which comes in the       */
/* source distribution.                                                   */
/*                                                                        */
/* All rights reserved.                                                   */
/*                                                                        */
/* NOTE: This software has received contributions from various other      */
/* contributors, only the core maintainers and supporters are listed as   */
/* copyright holders. Please contact us, if you feel you should be listed */
/* as copyright holder, as well.                                          */
/*                                                                        */
/**************************************************************************/

#ifndef DecodeBuffer_H
#define DecodeBuffer_H

#include <string.h>

#include "IntCache.h"
#include "CharCache.h"
#include "XidCache.h"
#include "FreeCache.h"
#include "OpcodeCache.h"
#include "ActionCache.h"

#define DECODE_BUFFER_OVERFLOW_SIZE        4194304

#define DECODE_BUFFER_POSTFIX_SIZE         1

class DecodeBuffer
{
  public:

  DecodeBuffer(const unsigned char *data, unsigned int length);

  ~DecodeBuffer()
  {
  }

  int decodeValue(unsigned int &value, unsigned int numBits,
                      unsigned int blockSize = 0, int endOkay = 0);

  int decodeCachedValue(unsigned int &value, unsigned int numBits,
                            IntCache &cache, unsigned int blockSize = 0,
                                int endOkay = 0);

  int decodeCachedValue(unsigned char &value, unsigned int numBits,
                            CharCache &cache, unsigned int blockSize = 0,
                                int endOkay = 0);

  void decodeDiffCachedValue(unsigned int &value, unsigned int &previous,
                                 unsigned int numBits, IntCache &cache,
                                     unsigned int blockSize = 0)
  {
    decodeCachedValue(value, numBits, cache, blockSize);

    previous += (value + 1);
    previous &= (0xffffffff >> (32 - numBits));

    value = previous;
  }

  void decodeBoolValue(unsigned int &value)
  {
    decodeValue(value, 1);
  }

  int decodeOpcodeValue(unsigned char &value, OpcodeCache &cache, int endOkay = 0)
  {
    int result = decodeCachedValue(value, 8, cache.base_[cache.slot_], 8, endOkay);

    if (result == 1)
    {
      cache.slot_ = value;
    }

    return result;
  }

  void decodeActionValue(unsigned char &value, unsigned short &position,
                             ActionCache &cache);

  void decodeNewXidValue(unsigned int &value, unsigned int &lastId,
                             IntCache &lastIdCache, IntCache &cache,
                                 FreeCache &freeCache);

  void decodeNewXidValue(unsigned int &value, unsigned int &lastId,
                             IntCache &lastIdCache, XidCache &cache,
                                 FreeCache &freeCache);

  void decodeXidValue(unsigned int &value, XidCache &cache);

  void decodeFreeXidValue(unsigned int &value, FreeCache &cache);

  void decodeTextData(unsigned char *buffer, unsigned int numBytes)
  {
    decodeMemory(buffer, numBytes);
  }

  void decodeIntData(unsigned char *buffer, unsigned int numBytes)
  {
    decodeMemory(buffer, numBytes);
  }

  void decodeLongData(unsigned char *buffer, unsigned int numBytes)
  {
    decodeMemory(buffer, numBytes);
  }

  const unsigned char *decodeMemory(unsigned int numBytes);

  void decodeMemory(unsigned char *buffer, unsigned int numBytes)
  {
    memcpy(buffer, decodeMemory(numBytes), numBytes);
  }

  private:

  const unsigned char *buffer_;
  const unsigned char *end_;
  const unsigned char *nextSrc_;

  unsigned char srcMask_;
};

#endif /* DecodeBuffer_H */