1 /* 7zCrc.c */

     2 

     3 #include "7zCrc.h"

     4 

     5 #define kCrcPoly 0xEDB88320

     6 UInt32 g_CrcTable[256];

     7 

     8 void MY_FAST_CALL CrcGenerateTable(void)

     9 {

    10   UInt32 i;

    11   for (i = 0; i < 256; i++)

    12   {

    13     UInt32 r = i;

    14     int j;

    15     for (j = 0; j < 8; j++)

    16       r = (r >> 1) ^ (kCrcPoly & ~((r & 1) - 1));

    17     g_CrcTable[i] = r;

    18   }

    19 }

    20 

    21 UInt32 MY_FAST_CALL CrcUpdate(UInt32 v, const void *data, size_t size)

    22 {

    23   const Byte *p = (const Byte *)data;

    24   for (; size > 0 ; size--, p++) 

    25     v = CRC_UPDATE_BYTE(v, *p);

    26   return v;

    27 }

    28 

    29 UInt32 MY_FAST_CALL CrcCalc(const void *data, size_t size)

    30 {

    31   return CrcUpdate(CRC_INIT_VAL, data, size) ^ 0xFFFFFFFF;

    32 }