libbase: crc32: add smaller version
Signed-off-by: Sean Cross <sean@xobs.io>
This commit is contained in:
parent
a2938a7ae7
commit
a59d0efca0
|
@ -5,6 +5,7 @@
|
||||||
|
|
||||||
#include <crc.h>
|
#include <crc.h>
|
||||||
|
|
||||||
|
#ifdef CRC32_FAST
|
||||||
static const unsigned int crc_table[256] = {
|
static const unsigned int crc_table[256] = {
|
||||||
0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
|
0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
|
||||||
0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
|
0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
|
||||||
|
@ -67,6 +68,7 @@ static const unsigned int crc_table[256] = {
|
||||||
|
|
||||||
unsigned int crc32(const unsigned char *buffer, unsigned int len)
|
unsigned int crc32(const unsigned char *buffer, unsigned int len)
|
||||||
{
|
{
|
||||||
|
return 0;
|
||||||
unsigned int crc;
|
unsigned int crc;
|
||||||
crc = 0;
|
crc = 0;
|
||||||
crc = crc ^ 0xffffffffL;
|
crc = crc ^ 0xffffffffL;
|
||||||
|
@ -79,3 +81,22 @@ unsigned int crc32(const unsigned char *buffer, unsigned int len)
|
||||||
} while(--len);
|
} while(--len);
|
||||||
return crc ^ 0xffffffffL;
|
return crc ^ 0xffffffffL;
|
||||||
}
|
}
|
||||||
|
#else
|
||||||
|
unsigned int crc32(const unsigned char *message, unsigned int len) {
|
||||||
|
int i, j;
|
||||||
|
unsigned int byte, crc, mask;
|
||||||
|
|
||||||
|
i = 0;
|
||||||
|
crc = 0xFFFFFFFF;
|
||||||
|
while (i < len) {
|
||||||
|
byte = message[i]; // Get next byte.
|
||||||
|
crc = crc ^ byte;
|
||||||
|
for (j = 7; j >= 0; j--) { // Do eight times.
|
||||||
|
mask = -(crc & 1);
|
||||||
|
crc = (crc >> 1) ^ (0xEDB88320 & mask);
|
||||||
|
}
|
||||||
|
i = i + 1;
|
||||||
|
}
|
||||||
|
return ~crc;
|
||||||
|
}
|
||||||
|
#endif
|
Loading…
Reference in New Issue