php-src/ext/hash/hash_fnv.c
2010-03-23 22:21:39 +00:00

230 lines
6.0 KiB
C

/*
+----------------------------------------------------------------------+
| PHP Version 5 |
+----------------------------------------------------------------------+
| Copyright (c) 1997-2010 The PHP Group |
+----------------------------------------------------------------------+
| This source file is subject to version 3.01 of the PHP license, |
| that is bundled with this package in the file LICENSE, and is |
| available through the world-wide-web at the following url: |
| http://www.php.net/license/3_01.txt |
| If you did not receive a copy of the PHP license and are unable to |
| obtain it through the world-wide-web, please send a note to |
| license@php.net so we can mail you a copy immediately. |
+----------------------------------------------------------------------+
| Author: Michael Maclean <mgdm@php.net> |
+----------------------------------------------------------------------+
*/
/* $Id$ */
/* Based on the public domain algorithm found at
http://www.isthe.com/chongo/tech/comp/fnv/index.html */
#include "php_hash.h"
#include "php_hash_fnv.h"
const php_hash_ops php_hash_fnv132_ops = {
(php_hash_init_func_t) PHP_FNV132Init,
(php_hash_update_func_t) PHP_FNV132Update,
(php_hash_final_func_t) PHP_FNV132Final,
(php_hash_copy_func_t) php_hash_copy,
4,
4,
sizeof(PHP_FNV132_CTX)
};
const php_hash_ops php_hash_fnv1a32_ops = {
(php_hash_init_func_t) PHP_FNV132Init,
(php_hash_update_func_t) PHP_FNV1a32Update,
(php_hash_final_func_t) PHP_FNV132Final,
(php_hash_copy_func_t) php_hash_copy,
4,
4,
sizeof(PHP_FNV132_CTX)
};
const php_hash_ops php_hash_fnv164_ops = {
(php_hash_init_func_t) PHP_FNV164Init,
(php_hash_update_func_t) PHP_FNV164Update,
(php_hash_final_func_t) PHP_FNV164Final,
(php_hash_copy_func_t) php_hash_copy,
8,
4,
sizeof(PHP_FNV164_CTX)
};
const php_hash_ops php_hash_fnv1a64_ops = {
(php_hash_init_func_t) PHP_FNV164Init,
(php_hash_update_func_t) PHP_FNV1a64Update,
(php_hash_final_func_t) PHP_FNV164Final,
(php_hash_copy_func_t) php_hash_copy,
8,
4,
sizeof(PHP_FNV164_CTX)
};
/* {{{ PHP_FNV132Init
* 32-bit FNV-1 hash initialisation
*/
PHP_HASH_API void PHP_FNV132Init(PHP_FNV132_CTX *context)
{
context->state = PHP_FNV1_32_INIT;
}
/* }}} */
PHP_HASH_API void PHP_FNV132Update(PHP_FNV132_CTX *context, const unsigned char *input,
unsigned int inputLen)
{
context->state = fnv_32_buf((void *)input, inputLen, context->state, 0);
}
PHP_HASH_API void PHP_FNV1a32Update(PHP_FNV132_CTX *context, const unsigned char *input,
unsigned int inputLen)
{
context->state = fnv_32_buf((void *)input, inputLen, context->state, 1);
}
PHP_HASH_API void PHP_FNV132Final(unsigned char digest[4], PHP_FNV132_CTX * context)
{
#ifdef WORDS_BIGENDIAN
memcpy(digest, &context->state, 4);
#else
int i = 0;
unsigned char *c = (unsigned char *) &context->state;
for (i = 0; i < 4; i++) {
digest[i] = c[3 - i];
}
#endif
}
/* {{{ PHP_FNV164Init
* 64-bit FNV-1 hash initialisation
*/
PHP_HASH_API void PHP_FNV164Init(PHP_FNV164_CTX *context)
{
context->state = PHP_FNV1_64_INIT;
}
/* }}} */
PHP_HASH_API void PHP_FNV164Update(PHP_FNV164_CTX *context, const unsigned char *input,
unsigned int inputLen)
{
context->state = fnv_64_buf((void *)input, inputLen, context->state, 0);
}
PHP_HASH_API void PHP_FNV1a64Update(PHP_FNV164_CTX *context, const unsigned char *input,
unsigned int inputLen)
{
context->state = fnv_64_buf((void *)input, inputLen, context->state, 1);
}
PHP_HASH_API void PHP_FNV164Final(unsigned char digest[8], PHP_FNV164_CTX * context)
{
#ifdef WORDS_BIGENDIAN
memcpy(digest, &context->state, 8);
#else
int i = 0;
unsigned char *c = (unsigned char *) &context->state;
for (i = 0; i < 8; i++) {
digest[i] = c[7 - i];
}
#endif
}
/*
* fnv_32_buf - perform a 32 bit Fowler/Noll/Vo hash on a buffer
*
* input:
* buf - start of buffer to hash
* len - length of buffer in octets
* hval - previous hash value or 0 if first call
* alternate - if > 0 use the alternate version
*
* returns:
* 32 bit hash as a static hash type
*/
static php_hash_uint32
fnv_32_buf(void *buf, size_t len, php_hash_uint32 hval, int alternate)
{
unsigned char *bp = (unsigned char *)buf; /* start of buffer */
unsigned char *be = bp + len; /* beyond end of buffer */
/*
* FNV-1 hash each octet in the buffer
*/
while (bp < be) {
if (alternate == 0) {
/* multiply by the 32 bit FNV magic prime mod 2^32 */
hval *= PHP_FNV_32_PRIME;
/* xor the bottom with the current octet */
hval ^= (php_hash_uint32)*bp++;
} else {
/* xor the bottom with the current octet */
hval ^= (php_hash_uint32)*bp++;
/* multiply by the 32 bit FNV magic prime mod 2^32 */
hval *= PHP_FNV_32_PRIME;
}
}
/* return our new hash value */
return hval;
}
/*
* fnv_64_buf - perform a 64 bit Fowler/Noll/Vo hash on a buffer
*
* input:
* buf - start of buffer to hash
* len - length of buffer in octets
* hval - previous hash value or 0 if first call
* alternate - if > 0 use the alternate version
*
* returns:
* 64 bit hash as a static hash type
*/
static php_hash_uint64
fnv_64_buf(void *buf, size_t len, php_hash_uint64 hval, int alternate)
{
unsigned char *bp = (unsigned char *)buf; /* start of buffer */
unsigned char *be = bp + len; /* beyond end of buffer */
/*
* FNV-1 hash each octet of the buffer
*/
while (bp < be) {
if (alternate == 0) {
/* multiply by the 64 bit FNV magic prime mod 2^64 */
hval *= PHP_FNV_64_PRIME;
/* xor the bottom with the current octet */
hval ^= (php_hash_uint64)*bp++;
} else {
/* xor the bottom with the current octet */
hval ^= (php_hash_uint64)*bp++;
/* multiply by the 64 bit FNV magic prime mod 2^64 */
hval *= PHP_FNV_64_PRIME;
}
}
/* return our new hash value */
return hval;
}
/*
* Local variables:
* tab-width: 4
* c-basic-offset: 4
* End:
* vim600: noet sw=4 ts=4 fdm=marker
* vim<600: noet sw=4 ts=4
*/