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comparison src/win32/7zip/7z/C/7zCrc.c @ 1:f9f4f1b99eed

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importing src directory
author Robert McIntyre <rlm@mit.edu>
date Sat, 03 Mar 2012 10:31:27 -0600
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0:8ced16adf2e1 1:f9f4f1b99eed
1 /* 7zCrc.c -- CRC32 calculation
2 2008-08-05
3 Igor Pavlov
4 Public domain */
5
6 #include "7zCrc.h"
7
8 #define kCrcPoly 0xEDB88320
9 UInt32 g_CrcTable[256];
10
11 void MY_FAST_CALL CrcGenerateTable(void)
12 {
13 UInt32 i;
14 for (i = 0; i < 256; i++)
15 {
16 UInt32 r = i;
17 int j;
18 for (j = 0; j < 8; j++)
19 r = (r >> 1) ^ (kCrcPoly & ~((r & 1) - 1));
20 g_CrcTable[i] = r;
21 }
22 }
23
24 UInt32 MY_FAST_CALL CrcUpdate(UInt32 v, const void *data, size_t size)
25 {
26 const Byte *p = (const Byte *)data;
27 for (; size > 0 ; size--, p++)
28 v = CRC_UPDATE_BYTE(v, *p);
29 return v;
30 }
31
32 UInt32 MY_FAST_CALL CrcCalc(const void *data, size_t size)
33 {
34 return CrcUpdate(CRC_INIT_VAL, data, size) ^ 0xFFFFFFFF;
35 }