qmk_firmware/lib/fnv/fnv32.c
Nick Brassel 01ecf332ff
Generic wear-leveling algorithm (#16996)
* Initial import of wear-leveling algorithm.

* Alignment.

* Docs tweaks.

* Lock/unlock.

* Update quantum/wear_leveling/wear_leveling_internal.h

Co-authored-by: Stefan Kerkmann <karlk90@pm.me>

* More tests, fix issue with consolidation when unlocked.

* More tests.

* Review comments.

* Add plumbing for FNV1a.

* Another test checking that checksum mismatch clears the cache.

* Check that the write log still gets played back.

Co-authored-by: Stefan Kerkmann <karlk90@pm.me>
2022-06-27 07:18:21 +10:00

467 lines
12 KiB
C

/*
* fnv32 - 32 bit Fowler/Noll/Vo hash of a buffer or string
*
* @(#) $Revision: 5.5 $
* @(#) $Id: fnv32.c,v 5.5 2012/03/21 01:38:12 chongo Exp $
* @(#) $Source: /usr/local/src/cmd/fnv/RCS/fnv32.c,v $
*
***
*
* Fowler/Noll/Vo hash
*
* The basis of this hash algorithm was taken from an idea sent
* as reviewer comments to the IEEE POSIX P1003.2 committee by:
*
* Phong Vo (http://www.research.att.com/info/kpv/)
* Glenn Fowler (http://www.research.att.com/~gsf/)
*
* In a subsequent ballot round:
*
* Landon Curt Noll (http://www.isthe.com/chongo/)
*
* improved on their algorithm. Some people tried this hash
* and found that it worked rather well. In an EMail message
* to Landon, they named it the ``Fowler/Noll/Vo'' or FNV hash.
*
* FNV hashes are designed to be fast while maintaining a low
* collision rate. The FNV speed allows one to quickly hash lots
* of data while maintaining a reasonable collision rate. See:
*
* http://www.isthe.com/chongo/tech/comp/fnv/index.html
*
* for more details as well as other forms of the FNV hash.
*
***
*
* Please do not copyright this code. This code is in the public domain.
*
* LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
* EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
* USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
* OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*
* By:
* chongo <Landon Curt Noll> /\oo/\
* http://www.isthe.com/chongo/
*
* Share and Enjoy! :-)
*/
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include "longlong.h"
#include "fnv.h"
#define WIDTH 32 /* bit width of hash */
#define BUF_SIZE (32*1024) /* number of bytes to hash at a time */
static char *usage =
"usage: %s [-b bcnt] [-m] [-s arg] [-t code] [-v] [arg ...]\n"
"\n"
"\t-b bcnt\tmask off all but the lower bcnt bits (default 32)\n"
"\t-m\tmultiple hashes, one per line for each arg\n"
"\t-s\thash arg as a string (ignoring terminating NUL bytes)\n"
"\t-t code\t test hash code: (0 ==> generate test vectors\n"
"\t\t\t\t 1 ==> validate against FNV test vectors)\n"
"\t-v\tverbose mode, print arg after hash (implies -m)\n"
"\targ\tstring (if -s was given) or filename (default stdin)\n"
"\n"
"\tNOTE: Programs that begin with fnv0 implement the FNV-0 hash.\n"
"\t The FNV-0 hash is historic FNV algorithm that is now deprecated.\n"
"\n"
"\tSee http://www.isthe.com/chongo/tech/comp/fnv/index.html for more info.\n"
"\n"
"\t@(#) FNV Version: %s\n";
static char *program; /* our name */
/*
* test_fnv32 - test the FNV32 hash
*
* given:
* hash_type type of FNV hash to test
* init_hval initial hash value
* mask lower bit mask
* v_flag 1 => print test failure info on stderr
* code 0 ==> generate FNV test vectors
* 1 ==> validate against FNV test vectors
*
* returns: 0 ==> OK, else test vector failure number
*/
static int
test_fnv32(enum fnv_type hash_type, Fnv32_t init_hval,
Fnv32_t mask, int v_flag, int code)
{
struct test_vector *t; /* FNV test vestor */
Fnv32_t hval; /* current hash value */
int tstnum; /* test vector that failed, starting at 1 */
/*
* print preamble if generating test vectors
*/
if (code == 0) {
switch (hash_type) {
case FNV0_32:
printf("struct fnv0_32_test_vector fnv0_32_vector[] = {\n");
break;
case FNV1_32:
printf("struct fnv1_32_test_vector fnv1_32_vector[] = {\n");
break;
case FNV1a_32:
printf("struct fnv1a_32_test_vector fnv1a_32_vector[] = {\n");
break;
default:
unknown_hash_type(program, hash_type, 12); /* exit(12) */
/*NOTREACHED*/
}
}
/*
* loop thru all test vectors
*/
for (t = fnv_test_str, tstnum = 1; t->buf != NULL; ++t, ++tstnum) {
/*
* compute the FNV hash
*/
hval = init_hval;
switch (hash_type) {
case FNV0_32:
case FNV1_32:
hval = fnv_32_buf(t->buf, t->len, hval);
break;
case FNV1a_32:
hval = fnv_32a_buf(t->buf, t->len, hval);
break;
default:
unknown_hash_type(program, hash_type, 13); /* exit(13) */
/*NOTREACHED*/
}
/*
* print the vector
*/
switch (code) {
case 0: /* generate the test vector */
printf(" { &fnv_test_str[%d], (Fnv32_t) 0x%08lxUL },\n",
tstnum-1, hval & mask);
break;
case 1: /* validate against test vector */
switch (hash_type) {
case FNV0_32:
if ((hval&mask) != (fnv0_32_vector[tstnum-1].fnv0_32 & mask)) {
if (v_flag) {
fprintf(stderr, "%s: failed fnv0_32 test # %d\n",
program, tstnum);
fprintf(stderr, "%s: test # 1 is 1st test\n", program);
fprintf(stderr,
"%s: expected 0x%08lx != generated: 0x%08lx\n",
program, (hval&mask),
(fnv0_32_vector[tstnum-1].fnv0_32 & mask));
}
return tstnum;
}
break;
case FNV1_32:
if ((hval&mask) != (fnv1_32_vector[tstnum-1].fnv1_32 & mask)) {
if (v_flag) {
fprintf(stderr, "%s: failed fnv1_32 test # %d\n",
program, tstnum);
fprintf(stderr, "%s: test # 1 is 1st test\n", program);
fprintf(stderr,
"%s: expected 0x%08lx != generated: 0x%08lx\n",
program, (hval&mask),
(fnv1_32_vector[tstnum-1].fnv1_32 & mask));
}
return tstnum;
}
break;
case FNV1a_32:
if ((hval&mask) != (fnv1a_32_vector[tstnum-1].fnv1a_32 &mask)) {
if (v_flag) {
fprintf(stderr, "%s: failed fnv1a_32 test # %d\n",
program, tstnum);
fprintf(stderr, "%s: test # 1 is 1st test\n", program);
fprintf(stderr,
"%s: expected 0x%08lx != generated: 0x%08lx\n",
program, (hval&mask),
(fnv1a_32_vector[tstnum-1].fnv1a_32 & mask));
}
return tstnum;
}
break;
}
break;
default:
fprintf(stderr, "%s: -m %d not implemented yet\n", program, code);
exit(14);
}
}
/*
* print completion if generating test vectors
*/
if (code == 0) {
printf(" { NULL, 0 }\n");
printf("};\n");
}
/*
* no failures, return code 0 ==> all OK
*/
return 0;
}
/*
* main - the main function
*
* See the above usage for details.
*/
int
main(int argc, char *argv[])
{
char buf[BUF_SIZE+1]; /* read buffer */
int readcnt; /* number of characters written */
Fnv32_t hval; /* current hash value */
int s_flag = 0; /* 1 => -s was given, hash args as strings */
int m_flag = 0; /* 1 => print multiple hashes, one per arg */
int v_flag = 0; /* 1 => verbose hash print */
int b_flag = WIDTH; /* -b flag value */
int t_flag = -1; /* FNV test vector code (0=>print, 1=>test) */
enum fnv_type hash_type = FNV_NONE; /* type of FNV hash to perform */
Fnv32_t bmask; /* mask to apply to output */
extern char *optarg; /* option argument */
extern int optind; /* argv index of the next arg */
int fd; /* open file to process */
char *p;
int i;
/*
* parse args
*/
program = argv[0];
while ((i = getopt(argc, argv, "b:mst:v")) != -1) {
switch (i) {
case 'b': /* bcnt bit mask count */
b_flag = atoi(optarg);
break;
case 'm': /* print multiple hashes, one per arg */
m_flag = 1;
break;
case 's': /* hash args as strings */
s_flag = 1;
break;
case 't': /* FNV test vector code */
t_flag = atoi(optarg);
if (t_flag < 0 || t_flag > 1) {
fprintf(stderr, "%s: -t code must be 0 or 1\n", program);
fprintf(stderr, usage, program, FNV_VERSION);
exit(1);
}
m_flag = 1;
break;
case 'v': /* verbose hash print */
m_flag = 1;
v_flag = 1;
break;
default:
fprintf(stderr, usage, program, FNV_VERSION);
exit(1);
}
}
/* -t code incompatible with -b, -m and args */
if (t_flag >= 0) {
if (b_flag != WIDTH) {
fprintf(stderr, "%s: -t code incompatible with -b\n", program);
exit(2);
}
if (s_flag != 0) {
fprintf(stderr, "%s: -t code incompatible with -s\n", program);
exit(3);
}
if (optind < argc) {
fprintf(stderr, "%s: -t code incompatible args\n", program);
exit(4);
}
}
/* -s requires at least 1 arg */
if (s_flag && optind >= argc) {
fprintf(stderr, usage, program, FNV_VERSION);
exit(5);
}
/* limit -b values */
if (b_flag < 0 || b_flag > WIDTH) {
fprintf(stderr, "%s: -b bcnt: %d must be >= 0 and < %d\n",
program, b_flag, WIDTH);
exit(6);
}
if (b_flag == WIDTH) {
bmask = (Fnv32_t)0xffffffff;
} else {
bmask = (Fnv32_t)((1 << b_flag) - 1);
}
/*
* start with the initial basis depending on the hash type
*/
p = strrchr(program, '/');
if (p == NULL) {
p = program;
} else {
++p;
}
if (strcmp(p, "fnv032") == 0) {
/* using non-recommended FNV-0 and zero initial basis */
hval = FNV0_32_INIT;
hash_type = FNV0_32;
} else if (strcmp(p, "fnv132") == 0) {
/* using FNV-1 and non-zero initial basis */
hval = FNV1_32_INIT;
hash_type = FNV1_32;
} else if (strcmp(p, "fnv1a32") == 0) {
/* start with the FNV-1a initial basis */
hval = FNV1_32A_INIT;
hash_type = FNV1a_32;
} else {
fprintf(stderr, "%s: unknown program name, unknown hash type\n",
program);
exit(7);
}
/*
* FNV test vector processing, if needed
*/
if (t_flag >= 0) {
int code; /* test vector that failed, starting at 1 */
/*
* perform all tests
*/
code = test_fnv32(hash_type, hval, bmask, v_flag, t_flag);
/*
* evaluate the tests
*/
if (code == 0) {
if (v_flag) {
printf("passed\n");
}
exit(0);
} else {
printf("failed vector (1 is 1st test): %d\n", code);
exit(8);
}
}
/*
* string hashing
*/
if (s_flag) {
/* hash any other strings */
for (i=optind; i < argc; ++i) {
switch (hash_type) {
case FNV0_32:
case FNV1_32:
hval = fnv_32_str(argv[i], hval);
break;
case FNV1a_32:
hval = fnv_32a_str(argv[i], hval);
break;
default:
unknown_hash_type(program, hash_type, 9); /* exit(9) */
/*NOTREACHED*/
}
if (m_flag) {
print_fnv32(hval, bmask, v_flag, argv[i]);
}
}
/*
* file hashing
*/
} else {
/*
* case: process only stdin
*/
if (optind >= argc) {
/* case: process only stdin */
while ((readcnt = read(0, buf, BUF_SIZE)) > 0) {
switch (hash_type) {
case FNV0_32:
case FNV1_32:
hval = fnv_32_buf(buf, readcnt, hval);
break;
case FNV1a_32:
hval = fnv_32a_buf(buf, readcnt, hval);
break;
default:
unknown_hash_type(program, hash_type, 10); /* exit(10) */
/*NOTREACHED*/
}
}
if (m_flag) {
print_fnv32(hval, bmask, v_flag, "(stdin)");
}
} else {
/*
* process any other files
*/
for (i=optind; i < argc; ++i) {
/* open the file */
fd = open(argv[i], O_RDONLY);
if (fd < 0) {
fprintf(stderr, "%s: unable to open file: %s\n",
program, argv[i]);
exit(4);
}
/* hash the file */
while ((readcnt = read(fd, buf, BUF_SIZE)) > 0) {
switch (hash_type) {
case FNV0_32:
case FNV1_32:
hval = fnv_32_buf(buf, readcnt, hval);
break;
case FNV1a_32:
hval = fnv_32a_buf(buf, readcnt, hval);
break;
default:
unknown_hash_type(program, hash_type, 11);/* exit(11) */
/*NOTREACHED*/
}
}
/* finish processing the file */
if (m_flag) {
print_fnv32(hval, bmask, v_flag, argv[i]);
}
close(fd);
}
}
}
/*
* report hash and exit
*/
if (!m_flag) {
print_fnv32(hval, bmask, v_flag, "");
}
return 0; /* exit(0); */
}