third_party/lzma_sdk/LzmaLib.h

   1 /* LzmaLib.h -- LZMA library interface
   2 2009-04-07 : Igor Pavlov : Public domain */
   3
   4 #ifndef __LZMA_LIB_H
   5 #define __LZMA_LIB_H
   6
   7 #include "Types.h"
   8
   9 #ifdef __cplusplus
  10 extern "C" {
  11 #endif
  12
  13 #define MY_STDAPI int MY_STD_CALL
  14
  15 #define LZMA_PROPS_SIZE 5
  16
  17 /*
  18 RAM requirements for LZMA:
  19   for compression:   (dictSize * 11.5 + 6 MB) + state_size
  20   for decompression: dictSize + state_size
  21     state_size = (4 + (1.5 << (lc + lp))) KB
  22     by default (lc=3, lp=0), state_size = 16 KB.
  23
  24 LZMA properties (5 bytes) format
  25     Offset Size  Description
  26       0     1    lc, lp and pb in encoded form.
  27       1     4    dictSize (little endian).
  28 */
  29
  30 /*
  31 LzmaCompress
  32 ------------
  33
  34 outPropsSize -
  35      In:  the pointer to the size of outProps buffer; *outPropsSize = LZMA_PROPS_SIZE = 5.
  36      Out: the pointer to the size of written properties in outProps buffer; *outPropsSize = LZMA_PROPS_SIZE = 5.
  37
  38   LZMA Encoder will use defult values for any parameter, if it is
  39   -1  for any from: level, loc, lp, pb, fb, numThreads
  40    0  for dictSize
  41
  42 level - compression level: 0 <= level <= 9;
  43
  44   level dictSize algo  fb
  45     0:    16 KB   0    32
  46     1:    64 KB   0    32
  47     2:   256 KB   0    32
  48     3:     1 MB   0    32
  49     4:     4 MB   0    32
  50     5:    16 MB   1    32
  51     6:    32 MB   1    32
  52     7+:   64 MB   1    64
  53
  54   The default value for "level" is 5.
  55
  56   algo = 0 means fast method
  57   algo = 1 means normal method
  58
  59 dictSize - The dictionary size in bytes. The maximum value is
  60         128 MB = (1 << 27) bytes for 32-bit version
  61           1 GB = (1 << 30) bytes for 64-bit version
  62      The default value is 16 MB = (1 << 24) bytes.
  63      It's recommended to use the dictionary that is larger than 4 KB and
  64      that can be calculated as (1 << N) or (3 << N) sizes.
  65
  66 lc - The number of literal context bits (high bits of previous literal).
  67      It can be in the range from 0 to 8. The default value is 3.
  68      Sometimes lc=4 gives the gain for big files.
  69
  70 lp - The number of literal pos bits (low bits of current position for literals).
  71      It can be in the range from 0 to 4. The default value is 0.
  72      The lp switch is intended for periodical data when the period is equal to 2^lp.
  73      For example, for 32-bit (4 bytes) periodical data you can use lp=2. Often it's
  74      better to set lc=0, if you change lp switch.
  75
  76 pb - The number of pos bits (low bits of current position).
  77      It can be in the range from 0 to 4. The default value is 2.
  78      The pb switch is intended for periodical data when the period is equal 2^pb.
  79
  80 fb - Word size (the number of fast bytes).
  81      It can be in the range from 5 to 273. The default value is 32.
  82      Usually, a big number gives a little bit better compression ratio and
  83      slower compression process.
  84
  85 numThreads - The number of thereads. 1 or 2. The default value is 2.
  86      Fast mode (algo = 0) can use only 1 thread.
  87
  88 Out:
  89   destLen  - processed output size
  90 Returns:
  91   SZ_OK               - OK
  92   SZ_ERROR_MEM        - Memory allocation error
  93   SZ_ERROR_PARAM      - Incorrect paramater
  94   SZ_ERROR_OUTPUT_EOF - output buffer overflow
  95   SZ_ERROR_THREAD     - errors in multithreading functions (only for Mt version)
  96 */
  97
  98 MY_STDAPI LzmaCompress(unsigned char *dest, size_t *destLen, const unsigned char *src, size_t srcLen,
  99   unsigned char *outProps, size_t *outPropsSize, /* *outPropsSize must be = 5 */
 100   int level,      /* 0 <= level <= 9, default = 5 */
 101   unsigned dictSize,  /* default = (1 << 24) */
 102   int lc,        /* 0 <= lc <= 8, default = 3  */
 103   int lp,        /* 0 <= lp <= 4, default = 0  */
 104   int pb,        /* 0 <= pb <= 4, default = 2  */
 105   int fb,        /* 5 <= fb <= 273, default = 32 */
 106   int numThreads /* 1 or 2, default = 2 */
 107   );
 108
 109 /*
 110 LzmaUncompress
 111 --------------
 112 In:
 113   dest     - output data
 114   destLen  - output data size
 115   src      - input data
 116   srcLen   - input data size
 117 Out:
 118   destLen  - processed output size
 119   srcLen   - processed input size
 120 Returns:
 121   SZ_OK                - OK
 122   SZ_ERROR_DATA        - Data error
 123   SZ_ERROR_MEM         - Memory allocation arror
 124   SZ_ERROR_UNSUPPORTED - Unsupported properties
 125   SZ_ERROR_INPUT_EOF   - it needs more bytes in input buffer (src)
 126 */
 127
 128 MY_STDAPI LzmaUncompress(unsigned char *dest, size_t *destLen, const unsigned char *src, SizeT *srcLen,
 129   const unsigned char *props, size_t propsSize);
 130
 131 #ifdef __cplusplus
 132 }
 133 #endif
 134
 135 #endif