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|
/*
+----------------------------------------------------------------------+
| PHP version 4.0 |
+----------------------------------------------------------------------+
| Copyright (c) 1997-2001 The PHP Group |
+----------------------------------------------------------------------+
| This source file is subject to version 2.02 of the PHP license, |
| that is bundled with this package in the file LICENSE, and is |
| available at through the world-wide-web at |
| http://www.php.net/license/2_02.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. |
+----------------------------------------------------------------------+
| Authors: Rasmus Lerdorf <rasmus@lerdorf.on.ca> |
| Zeev Suraski <zeev@zend.com> |
| Pedro Melo <melo@ip.pt> |
| Jeroen van Wolffelaar <jeroen@php.net> |
| |
| Based on code from: Shawn Cokus <Cokus@math.washington.edu> |
+----------------------------------------------------------------------+
*/
/* $Id$ */
/* Layout implementation random functions
*
* The PHPAPI contains these functions:
* - long php_rand()
* - long php_rand_range(long min, long max)
* - void php_srand()
* - long php_getrandmax()
*
* Note that it is not possible to choose the algoritm. This is done to
* give the user the possibility to control all randomness by means of
* srand()/php.ini in a portable and consistent way.
*
* rand.c: (the only rand*.c file with PHP_API and PHP_FUNCTION functions)
*
* - PHP_FUNCTION([mt_]srand)
* +-> void php_srand(void)
* +-> void php_srand2(long seed, int alg)
* +-> (rand_sys.c) long php_rand_sys()
* +-> (rand_mt.c ) long php_rand_mt()
*
* - PHP_FUNCTION([mt_]rand)
* +-> long php_rand()
* +-> (rand_sys.c) long php_rand_sys()
* +-> (rand_mt.c ) long php_rand_mt()
* +-> long php_rand_range(long min, long max)
* +-> calls php_rand()
*
* - PHP_FUNCTION([mt_]getrandmax)
* +-> PHPAPI long php_randmax(void)
* +-> (rand_sys.c) long php_randmax_sys()
* +-> (rand_mt.c ) long php_randmax_mt()
*
* --Jeroen
*/
/* TODO:
* - make constants available to PHP-user
* - MINFO section about which random number generators are available
* - Nuke randmax by enhancing PHP_RAND_RANGE to work well in the case of a
* greater request than the real (internal) randmax is
* - Implement LCG
* - Implement a real-random source? (via internet, and/or /dev/urandom?)
* - Can lrand48 be thread-safe?
* - Is random() useful sometimes?
* - Which system algorithms are available, maybe name them after real
* algorithm by compile-time detection?
* - Get this to compile :-)
*/
#ifndef PHP_RAND_H
#define PHP_RAND_H
#include <stdlib.h>
/* FIXME: that '_php_randgen_entry' needed, or not? */
typedef struct _php_randgen_entry {
void (*srand)(long seed);
long (*rand)(void);
long randmax;
char *ini_str;
} php_randgen_entry;
/* an ARRAY of POINTERS, not vice versa */
extern php_randgen_entry *php_randgen_entries[];
#define PHP_RANDGEN_ENTRY(which, nsrand, nrand, nrandmax, nini_str) { \
php_randgen_entries[which] = emalloc(sizeof(php_randgen_entry)); \
php_randgen_entries[which]->srand = nsrand; \
php_randgen_entries[which]->rand = nrand; \
php_randgen_entries[which]->randmax = nrandmax; \
php_randgen_entries[which]->ini_str = nini_str; \
}
/* Define random generator constants */
#define PHP_RAND_SYS 0
#define PHP_RAND_LRAND48 1
#define PHP_RAND_MT 2
#define PHP_RAND_LCG 3
#define PHP_RAND_DEFAULT PHP_RAND_MT
/* how many there are */
#define PHP_RAND_NUMRANDS 4
/* Proto's */
PHP_FUNCTION(srand);
PHP_FUNCTION(rand);
PHP_FUNCTION(getrandmax);
PHP_FUNCTION(mt_srand);
PHP_FUNCTION(mt_rand);
PHP_FUNCTION(mt_getrandmax);
PHPAPI long php_rand(void);
PHPAPI long php_rand_range(long min, long max);
PHPAPI double php_drand(void);
PHPAPI long php_randmax(void);
#endif /* PHP_RAND_H */
/*
* Local variables:
* tab-width: 4
* c-basic-offset: 4
* End:
* vim600: fdm=marker
* vim: sw=4 ts=4 tw=78
*/
|
