diff options
Diffstat (limited to 'adventure/crc.c')
| -rw-r--r-- | adventure/crc.c | 53 |
1 files changed, 31 insertions, 22 deletions
diff --git a/adventure/crc.c b/adventure/crc.c index 8626f348..dafd7626 100644 --- a/adventure/crc.c +++ b/adventure/crc.c @@ -1,4 +1,4 @@ -/* $NetBSD: crc.c,v 1.12 2012/01/07 18:08:35 dholland Exp $ */ +/* $NetBSD: crc.c,v 1.13 2012/01/08 18:16:00 dholland Exp $ */ /*- * Copyright (c) 1993 @@ -38,13 +38,13 @@ static char sccsid[] = "@(#)crc.c 8.1 (Berkeley) 5/31/93"; static char ORIGINAL_sccsid[] = "@(#)crc.c 5.2 (Berkeley) 4/4/91"; #else -__RCSID("$NetBSD: crc.c,v 1.12 2012/01/07 18:08:35 dholland Exp $"); +__RCSID("$NetBSD: crc.c,v 1.13 2012/01/08 18:16:00 dholland Exp $"); #endif #endif /* not lint */ #include "extern.h" -static const unsigned long crctab[] = { +static const uint32_t crctab[256] = { 0x7fffffff, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, @@ -98,6 +98,7 @@ static const unsigned long crctab[] = { 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d }; + /* * crc -- * Compute a POSIX.2 checksum. This routine modified by Jim Gillogly @@ -106,31 +107,39 @@ static const unsigned long crctab[] = { * it. */ -static unsigned long crcval; -static unsigned int step; - void -crc_start(void) +crc_start(struct crcstate *c) { - crcval = step = 0; + c->crcval = 0; + c->step = 0; } -/* Process nr bytes at a time; ptr points to them */ -unsigned long -crc(const char *ptr, int nr) +/* + * Process NUM bytes pointed to by DATA + */ +void +crc_add(struct crcstate *c, const void *data, size_t num) { - int i; - const char *p; + const unsigned char *udata; + size_t pos; + unsigned x; - while (nr > 0) - for (p = ptr; nr--; ++p) { - i = (crcval >> 24 ^ (unsigned char)*p) & 0xff; - if (i == 0) { - i = step++; - if (step >= sizeof(crctab) / sizeof(crctab[0])) - step = 0; + udata = data; + pos = 0; + while (pos < num) { + x = (c->crcval >> 24 ^ udata[pos++]) & 0xff; + if (x == 0) { + x = c->step++; + if (c->step >= __arraycount(crctab)) { + c->step = 0; } - crcval = (crcval << 8) ^ crctab[i]; } - return crcval & 0xffffffff; /* Mask to 32 bits. */ + c->crcval = (c->crcval << 8) ^ crctab[x]; + } +} + +uint32_t +crc_get(struct crcstate *c) +{ + return c->crcval; } |