summaryrefslogtreecommitdiffstats
path: root/lz4.h
blob: 3680121c0ab30499a57805e5e1db4d2b31a15cfc (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
/*

   LZ4 - Fast LZ compression algorithm

   Header File

   Copyright (C) 2011-2012, Yann Collet.

   BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)



   Redistribution and use in source and binary forms, with or without

   modification, are permitted provided that the following conditions are

   met:



       * Redistributions of source code must retain the above copyright

   notice, this list of conditions and the following disclaimer.

       * Redistributions in binary form must reproduce the above

   copyright notice, this list of conditions and the following disclaimer

   in the documentation and/or other materials provided with the

   distribution.



   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.



   You can contact the author at :

   - LZ4 homepage : http://fastcompression.blogspot.com/p/lz4.html

   - LZ4 source repository : http://code.google.com/p/lz4/

*/
#pragma once


#if defined (__cplusplus)

extern "C" {
#endif



//**************************************

// Compiler Options

//**************************************

#ifdef _MSC_VER   // Visual Studio

#  define inline __inline           // Visual is not C99, but supports some kind of inline

#endif



//****************************

// Simple Functions

//****************************


int LZ4_compress   (const char* source, char* dest, int isize);
int LZ4_uncompress (const char* source, char* dest, int osize);

/*

LZ4_compress() :

    Compresses 'isize' bytes from 'source' into 'dest'.

    Destination buffer must be already allocated,

    and must be sized to handle worst cases situations (input data not compressible)

    Worst case size evaluation is provided by function LZ4_compressBound()



    isize  : is the input size. Max supported value is ~1.9GB

    return : the number of bytes written in buffer dest





LZ4_uncompress() :

    osize  : is the output size, therefore the original size

    return : the number of bytes read in the source buffer

             If the source stream is malformed, the function will stop decoding and return a negative result, indicating the byte position of the faulty instruction

             This function never writes outside of provided buffers, and never modifies input buffer.

    note : destination buffer must be already allocated.

           its size must be a minimum of 'osize' bytes.

*/


//****************************

// Advanced Functions

//****************************


static inline int LZ4_compressBound(int isize)   { return ((isize) + ((isize)/255) + 16); }
#define           LZ4_COMPRESSBOUND(    isize)            ((isize) + ((isize)/255) + 16)


/*

LZ4_compressBound() :

    Provides the maximum size that LZ4 may output in a "worst case" scenario (input data not compressible)

    primarily useful for memory allocation of output buffer.

	inline function is recommended for the general case,

	but macro is also provided when results need to be evaluated at compile time (such as table size allocation).



    isize  : is the input size. Max supported value is ~1.9GB

    return : maximum output size in a "worst case" scenario

    note : this function is limited by "int" range (2^31-1)

*/


int LZ4_compress_limitedOutput   (const char* source, char* dest, int isize, int maxOutputSize);

/*

LZ4_compress_limitedOutput() :

    Compress 'isize' bytes from 'source' into an output buffer 'dest' of maximum size 'maxOutputSize'.

    If it cannot achieve it, compression will stop, and result of the function will be zero.

    This function never writes outside of provided output buffer.



    isize  : is the input size. Max supported value is ~1.9GB

    maxOutputSize : is the size of the destination buffer (which must be already allocated)

    return : the number of bytes written in buffer 'dest'

             or 0 if the compression fails

*/


int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize);

/*

LZ4_uncompress_unknownOutputSize() :

    isize  : is the input size, therefore the compressed size

    maxOutputSize : is the size of the destination buffer (which must be already allocated)

    return : the number of bytes decoded in the destination buffer (necessarily <= maxOutputSize)

             If the source stream is malformed, the function will stop decoding and return a negative result, indicating the byte position of the faulty instruction

             This function never writes beyond dest + maxOutputSize, and is therefore protected against malicious data packets

    note   : Destination buffer must be already allocated.

             This version is slightly slower than LZ4_uncompress()

*/


#if defined (__cplusplus)

}
#endif