php-src/ext/hash/hash_joaat.c
2015-01-15 23:27:30 +08:00

100 lines
2.8 KiB
C

/*
+----------------------------------------------------------------------+
| PHP Version 7 |
+----------------------------------------------------------------------+
| Copyright (c) 1997-2015 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: Martin Jansen <mj@php.net> |
+----------------------------------------------------------------------+
*/
/* $Id$ */
/* Implements Jenkins's one-at-a-time hashing algorithm as presented on
* http://www.burtleburtle.net/bob/hash/doobs.html.
*/
#include "php_hash.h"
#include "php_hash_joaat.h"
const php_hash_ops php_hash_joaat_ops = {
(php_hash_init_func_t) PHP_JOAATInit,
(php_hash_update_func_t) PHP_JOAATUpdate,
(php_hash_final_func_t) PHP_JOAATFinal,
(php_hash_copy_func_t) php_hash_copy,
4,
4,
sizeof(PHP_JOAAT_CTX)
};
PHP_HASH_API void PHP_JOAATInit(PHP_JOAAT_CTX *context)
{
context->state = 0;
}
PHP_HASH_API void PHP_JOAATUpdate(PHP_JOAAT_CTX *context, const unsigned char *input, unsigned int inputLen)
{
context->state = joaat_buf((void *)input, inputLen, context->state);
}
PHP_HASH_API void PHP_JOAATFinal(unsigned char digest[4], PHP_JOAAT_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
context->state = 0;
}
/*
* joaat_buf - perform a Jenkins's one-at-a-time hash on a buffer
*
* input:
* buf - start of buffer to hash
* len - length of buffer in octets
*
* returns:
* 32 bit hash as a static hash type
*/
static php_hash_uint32
joaat_buf(void *buf, size_t len, php_hash_uint32 hval)
{
size_t i;
unsigned char *input = (unsigned char *)buf;
for (i = 0; i < len; i++) {
hval += input[i];
hval += (hval << 10);
hval ^= (hval >> 6);
}
hval += (hval << 3);
hval ^= (hval >> 11);
hval += (hval << 15);
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
*/