nel/3rdparty/seven_zip/LzmaLib.h

   1 /* LzmaLib.h -- LZMA library interface
   2 2013-01-18 : Igor Pavlov : Public domain */
   3
   4 #ifndef __LZMA_LIB_H
   5 #define __LZMA_LIB_H
   6
   7 #include "7zTypes.h"
   8
   9 EXTERN_C_BEGIN
  10
  11 #define MY_STDAPI int MY_STD_CALL
  12
  13 #define LZMA_PROPS_SIZE 5
  14
  15 /*
  16 RAM requirements for LZMA:
  17   for compression:   (dictSize * 11.5 + 6 MB) + state_size
  18   for decompression: dictSize + state_size
  19     state_size = (4 + (1.5 << (lc + lp))) KB
  20     by default (lc=3, lp=0), state_size = 16 KB.
  21
  22 LZMA properties (5 bytes) format
  23     Offset Size  Description
  24       0     1    lc, lp and pb in encoded form.
  25       1     4    dictSize (little endian).
  26 */
  27
  28 /*
  29 LzmaCompress
  30 ------------
  31
  32 outPropsSize -
  33      In:  the pointer to the size of outProps buffer; *outPropsSize = LZMA_PROPS_SIZE = 5.
  34      Out: the pointer to the size of written properties in outProps buffer; *outPropsSize = LZMA_PROPS_SIZE = 5.
  35
  36   LZMA Encoder will use defult values for any parameter, if it is
  37   -1  for any from: level, loc, lp, pb, fb, numThreads
  38    0  for dictSize
  39
  40 level - compression level: 0 <= level <= 9;
  41
  42   level dictSize algo  fb
  43     0:    16 KB   0    32
  44     1:    64 KB   0    32
  45     2:   256 KB   0    32
  46     3:     1 MB   0    32
  47     4:     4 MB   0    32
  48     5:    16 MB   1    32
  49     6:    32 MB   1    32
  50     7+:   64 MB   1    64
  51
  52   The default value for "level" is 5.
  53
  54   algo = 0 means fast method
  55   algo = 1 means normal method
  56
  57 dictSize - The dictionary size in bytes. The maximum value is
  58         128 MB = (1 << 27) bytes for 32-bit version
  59           1 GB = (1 << 30) bytes for 64-bit version
  60      The default value is 16 MB = (1 << 24) bytes.
  61      It's recommended to use the dictionary that is larger than 4 KB and
  62      that can be calculated as (1 << N) or (3 << N) sizes.
  63
  64 lc - The number of literal context bits (high bits of previous literal).
  65      It can be in the range from 0 to 8. The default value is 3.
  66      Sometimes lc=4 gives the gain for big files.
  67
  68 lp - The number of literal pos bits (low bits of current position for literals).
  69      It can be in the range from 0 to 4. The default value is 0.
  70      The lp switch is intended for periodical data when the period is equal to 2^lp.
  71      For example, for 32-bit (4 bytes) periodical data you can use lp=2. Often it's
  72      better to set lc=0, if you change lp switch.
  73
  74 pb - The number of pos bits (low bits of current position).
  75      It can be in the range from 0 to 4. The default value is 2.
  76      The pb switch is intended for periodical data when the period is equal 2^pb.
  77
  78 fb - Word size (the number of fast bytes).
  79      It can be in the range from 5 to 273. The default value is 32.
  80      Usually, a big number gives a little bit better compression ratio and
  81      slower compression process.
  82
  83 numThreads - The number of thereads. 1 or 2. The default value is 2.
  84      Fast mode (algo = 0) can use only 1 thread.
  85
  86 Out:
  87   destLen  - processed output size
  88 Returns:
  89   SZ_OK               - OK
  90   SZ_ERROR_MEM        - Memory allocation error
  91   SZ_ERROR_PARAM      - Incorrect paramater
  92   SZ_ERROR_OUTPUT_EOF - output buffer overflow
  93   SZ_ERROR_THREAD     - errors in multithreading functions (only for Mt version)
  94 */
  95
  96 MY_STDAPI LzmaCompress(unsigned char *dest, size_t *destLen, const unsigned char *src, size_t srcLen,
  97   unsigned char *outProps, size_t *outPropsSize, /* *outPropsSize must be = 5 */
  98   int level,      /* 0 <= level <= 9, default = 5 */
  99   unsigned dictSize,  /* default = (1 << 24) */
 100   int lc,        /* 0 <= lc <= 8, default = 3  */
 101   int lp,        /* 0 <= lp <= 4, default = 0  */
 102   int pb,        /* 0 <= pb <= 4, default = 2  */
 103   int fb,        /* 5 <= fb <= 273, default = 32 */
 104   int numThreads /* 1 or 2, default = 2 */
 105   );
 106
 107 /*
 108 LzmaUncompress
 109 --------------
 110 In:
 111   dest     - output data
 112   destLen  - output data size
 113   src      - input data
 114   srcLen   - input data size
 115 Out:
 116   destLen  - processed output size
 117   srcLen   - processed input size
 118 Returns:
 119   SZ_OK                - OK
 120   SZ_ERROR_DATA        - Data error
 121   SZ_ERROR_MEM         - Memory allocation arror
 122   SZ_ERROR_UNSUPPORTED - Unsupported properties
 123   SZ_ERROR_INPUT_EOF   - it needs more bytes in input buffer (src)
 124 */
 125
 126 MY_STDAPI LzmaUncompress(unsigned char *dest, size_t *destLen, const unsigned char *src, SizeT *srcLen,
 127   const unsigned char *props, size_t propsSize);
 128
 129 EXTERN_C_END
 130
 131 #endif