mirror of
https://github.com/php/php-src.git
synced 2025-01-25 21:23:45 +08:00
320 lines
9.6 KiB
C
320 lines
9.6 KiB
C
/*
|
|
+----------------------------------------------------------------------+
|
|
| 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> |
|
|
+----------------------------------------------------------------------+
|
|
*/
|
|
/* $Id$ */
|
|
|
|
#include <stdlib.h>
|
|
|
|
#include "php.h"
|
|
#include "php_math.h"
|
|
#include "php_rand.h"
|
|
#include "php_lcg.h"
|
|
#include "php_ini.h"
|
|
|
|
#include "zend_execute.h"
|
|
|
|
#include "basic_functions.h"
|
|
|
|
/* See php_rand.h for information about layout */
|
|
|
|
/* an ARRAY of POINTERS, not vice versa */
|
|
php_randgen_entry *php_randgen_entries[PHP_RAND_NUMRANDS];
|
|
|
|
#define PHP_HAS_SRAND(which) (php_randgen_entries[which] && php_randgen_entries[which]->srand)
|
|
#define PHP_SRAND(which,seed) ((*(php_randgen_entries[which]->srand))(seed))
|
|
#define PHP_RAND(which) ((*(php_randgen_entries[which]->rand))())
|
|
#define PHP_RANDMAX(which) (php_randgen_entries[which]->randmax)
|
|
#define PHP_RAND_INISTR(which) (php_randgen_entries[which]->ini_str)
|
|
|
|
#define CURR_GEN BG(rand_generator_current)
|
|
|
|
PHP_MINIT_FUNCTION(rand)
|
|
{
|
|
PHP_MINIT(rand_sys)(INIT_FUNC_ARGS_PASSTHRU);
|
|
PHP_MINIT(rand_mt)(INIT_FUNC_ARGS_PASSTHRU);
|
|
/* lcg not yet implemented */
|
|
php_randgen_entries[PHP_RAND_LCG] = NULL;
|
|
}
|
|
|
|
/* TODO: check that this function is called on the start of each script
|
|
* execution: not more often, not less often.
|
|
*
|
|
* Note that system rand is inherently thread-unsafe: A different thread can
|
|
* always eat up some rand()'s, and thus nuking your expected sequence.
|
|
* Another reason to use MT...
|
|
*/
|
|
PHP_RINIT_FUNCTION(rand)
|
|
{
|
|
register int i;
|
|
|
|
/* seed all number-generators */
|
|
/* FIXME: or seed relevant numgen on init/update ini-entry? */
|
|
for (i = 0 ; i < PHP_RAND_NUMRANDS ; i++) {
|
|
if (PHP_HAS_SRAND(i)) {
|
|
#define SRAND_A_RANDOM_SEED ((long)time(0) * (long)getpid() * (long)(php_combined_lcg(TSRMLS_C) * 10000.0)) /* something with microtime? */
|
|
PHP_SRAND(i,SRAND_A_RANDOM_SEED);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* INI */
|
|
static int randgen_str_to_int(char *str, int strlen)
|
|
{
|
|
register int i;
|
|
|
|
for (i = 0 ; i < PHP_RAND_NUMRANDS ; i++) {
|
|
if (!strcasecmp(str, PHP_RAND_INISTR(i)))
|
|
return i;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
/* FIXME: check that this is called on initial ini-parsing too */
|
|
/* FIXME: what if no ini-entry was present? */
|
|
static PHP_INI_MH(OnUpdateRandGen)
|
|
{
|
|
/* Set BG(rand_generator) to the correct integer value indicating
|
|
* ini-setting */
|
|
BG(rand_generator) = randgen_str_to_int(new_value, new_value_length);
|
|
if (BG(rand_generator) == -1) {
|
|
/* FIXME: is this possible? What happens if this occurs during
|
|
* ini-parsing at startup? */
|
|
php_error(E_WARNING,"Invalid value for random_number_generator: \"%s\"", new_value);
|
|
/* Fallback: */
|
|
BG(rand_generator) = PHP_RAND_DEFAULT;
|
|
}
|
|
#ifdef DEBUG_RAND
|
|
printf("\nRAND-INI updated: %d\n",BG(rand_generator));
|
|
#endif
|
|
return SUCCESS;
|
|
}
|
|
|
|
PHP_INI_BEGIN()
|
|
/* FIXME: default is hardcoded here, this is the second place */
|
|
PHP_INI_ENTRY("random_number_generator", "mt", PHP_INI_ALL, OnUpdateRandGen)
|
|
PHP_INI_END()
|
|
|
|
/* srand */
|
|
|
|
/* FIXME: isn't used? */
|
|
/* {{{ void php_srand(void) */
|
|
static void php_srand(TSRMLS_D)
|
|
{
|
|
CURR_GEN = BG(rand_generator);
|
|
PHP_SRAND(BG(rand_generator), SRAND_A_RANDOM_SEED);
|
|
}
|
|
/* }}} */
|
|
|
|
/* {{{ [mt_]srand common */
|
|
#define pim_srand_common(name,type) \
|
|
PHP_FUNCTION(name) \
|
|
{ \
|
|
zval **seed; \
|
|
zval **alg; \
|
|
TSRMLS_FETCH(); \
|
|
\
|
|
switch (ZEND_NUM_ARGS()) { \
|
|
case 0: \
|
|
CURR_GEN = BG(rand_generator); \
|
|
PHP_SRAND(BG(rand_generator), SRAND_A_RANDOM_SEED); \
|
|
RETURN_TRUE; \
|
|
case 1: \
|
|
zend_get_parameters_ex(1, &seed); \
|
|
convert_to_long_ex(seed); \
|
|
CURR_GEN = type; \
|
|
PHP_SRAND(type, Z_LVAL_PP(seed)); \
|
|
RETURN_TRUE; \
|
|
case 2: \
|
|
/* algorithm, seed is most logic, though it is the other way
|
|
* around than current way... */ \
|
|
zend_get_parameters_ex(2, &alg, &seed); \
|
|
convert_to_long_ex(seed); \
|
|
convert_to_long_ex(alg); \
|
|
if (0 > Z_LVAL_PP(alg) || Z_LVAL_PP(alg) >= PHP_RAND_NUMRANDS) { \
|
|
php_error(E_WARNING, "%s(): There is no algorithm %d.", get_active_function_name(TSRMLS_C), Z_LVAL_PP(alg)); \
|
|
RETURN_FALSE; \
|
|
} \
|
|
if (!PHP_HAS_SRAND(Z_LVAL_PP(alg))) { \
|
|
php_error(E_WARNING, "%s(): Algorithm %d does not support reproducable results.", get_active_function_name(TSRMLS_C), Z_LVAL_PP(alg)); \
|
|
RETURN_FALSE; \
|
|
} \
|
|
CURR_GEN = Z_LVAL_PP(alg); \
|
|
PHP_SRAND(Z_LVAL_PP(alg), Z_LVAL_PP(seed)); \
|
|
RETURN_TRUE; \
|
|
default: \
|
|
WRONG_PARAM_COUNT; \
|
|
} \
|
|
}
|
|
/* }}} */
|
|
|
|
/* {{{ proto bool srand(int seed)
|
|
Seeds random number generator */
|
|
pim_srand_common(srand,PHP_RAND_SYS)
|
|
/* }}} */
|
|
|
|
/* {{{ proto bool mt_srand(int seed)
|
|
Seeds random number generator */
|
|
pim_srand_common(mt_srand,PHP_RAND_MT)
|
|
/* }}} */
|
|
|
|
/* rand */
|
|
|
|
/* {{{ PHPAPI long php_rand(void) */
|
|
PHPAPI long php_rand(void)
|
|
{
|
|
return PHP_RAND(CURR_GEN);
|
|
}
|
|
/* }}} */
|
|
|
|
/* {{{ PHPAPI double php_drand(void)
|
|
* returns a double in the range [0,1) */
|
|
PHPAPI double php_drand(void)
|
|
{
|
|
return (double)php_rand() /
|
|
(double)(PHP_RANDMAX(CURR_GEN)+1.0);
|
|
}
|
|
/* }}} */
|
|
|
|
/* {{{ macro: PHP_RAND_RANGE */
|
|
#define PHP_RAND_RANGE(which,min,max,result) { \
|
|
/*
|
|
* A bit of tricky math here. We want to avoid using a modulus because
|
|
* that simply tosses the high-order bits and might skew the distribution
|
|
* of random values over the range. Instead we map the range directly.
|
|
*
|
|
* We need to map the range from 0...M evenly to the range a...b
|
|
* Expressed in real numbers, this becomes:
|
|
*
|
|
* [0,M+1[ mapped to [a,b+1[
|
|
*
|
|
* Let n = the random number and n' = the mapped random number
|
|
* So the formula needs to be:
|
|
*
|
|
* n' = a + n((b+1)-a)/(m+1)
|
|
*
|
|
* This isn't perfect, because n only takes integer values. So when a..b
|
|
* spans a significant portion of 0..M, some numbers have nearly twice as
|
|
* much chance. But since twice a very small chance is still a very small
|
|
* chance, it's ignored.
|
|
*
|
|
* --Rasmus and Jeroen
|
|
*/ \
|
|
(result) = PHP_RAND(which); \
|
|
if ((max) < (min)) { \
|
|
php_error(E_WARNING, "%s(): Invalid range: %ld..%ld (minimum can't be larger than maximum)", \
|
|
get_active_function_name(TSRMLS_C), (min), (max)); \
|
|
} else if ( (max) - (min) > PHP_RANDMAX(which) ) { \
|
|
/* TODO: this can done better, get two numbers and combine... */ \
|
|
php_error(E_WARNING, "%s(): Invalid range: %ld..%ld (can't give that much randomness)", \
|
|
get_active_function_name(TSRMLS_C), (min), (max)); \
|
|
} \
|
|
(result) = (min) + (long) ((double)((max)-(min)+1) * (result)/(PHP_RANDMAX(which)+1.0)); \
|
|
}
|
|
/* }}} */
|
|
|
|
/* {{{ PHPAPI long php_rand_range(long min, long max) */
|
|
PHPAPI long php_rand_range(long min, long max TSRMLS_DC)
|
|
{
|
|
register long result;
|
|
|
|
PHP_RAND_RANGE(CURR_GEN, min, max, result);
|
|
return result;
|
|
}
|
|
/* }}} */
|
|
|
|
/* {{{ [mt_]rand common */
|
|
#define PHP_FUNCTION_RAND(name,which) \
|
|
PHP_FUNCTION(name) \
|
|
{ \
|
|
zval **min, **max; \
|
|
\
|
|
switch (ZEND_NUM_ARGS()) { \
|
|
case 0: \
|
|
RETURN_LONG(PHP_RAND(which)); \
|
|
case 2: \
|
|
if (zend_get_parameters_ex(2, &min, &max)==FAILURE) { \
|
|
RETURN_FALSE; \
|
|
} \
|
|
convert_to_long_ex(min); \
|
|
convert_to_long_ex(max); \
|
|
Z_TYPE_P(return_value) = IS_LONG; \
|
|
PHP_RAND_RANGE(which, Z_LVAL_PP(min), \
|
|
Z_LVAL_PP(max), Z_LVAL_P(return_value)); \
|
|
return; \
|
|
default: \
|
|
WRONG_PARAM_COUNT; \
|
|
break; \
|
|
} \
|
|
}
|
|
/* }}} */
|
|
|
|
/* {{{ proto int rand([int min, int max])
|
|
Returns a random number */
|
|
PHP_FUNCTION_RAND(rand,PHP_RAND_SYS)
|
|
/* }}} */
|
|
|
|
/* {{{ proto int mt_rand([int min, int max])
|
|
Returns a random number by means of Mersenne Twister */
|
|
PHP_FUNCTION_RAND(mt_rand,PHP_RAND_MT)
|
|
/* }}} */
|
|
|
|
/* getrandmax */
|
|
|
|
/* {{{ PHPAPI long php_randmax(void)
|
|
Returns the maximum value a random number can have */
|
|
PHPAPI long php_randmax(void)
|
|
{
|
|
return PHP_RANDMAX(CURR_GEN);
|
|
}
|
|
/* }}} */
|
|
|
|
/* {{{ proto int getrandmax(void)
|
|
Returns the maximum value a random number can have */
|
|
PHP_FUNCTION(getrandmax)
|
|
{
|
|
if (ZEND_NUM_ARGS() != 0) {
|
|
WRONG_PARAM_COUNT;
|
|
}
|
|
|
|
RETURN_LONG( php_randmax());
|
|
}
|
|
/* }}} */
|
|
|
|
/* {{{ proto int mt_getrandmax(void)
|
|
Returns the maximum value a random number can have */
|
|
PHP_FUNCTION(mt_getrandmax)
|
|
{
|
|
if (ZEND_NUM_ARGS() != 0) {
|
|
WRONG_PARAM_COUNT;
|
|
}
|
|
|
|
RETURN_LONG( php_randmax() );
|
|
}
|
|
/* }}} */
|
|
|
|
/*
|
|
* Local variables:
|
|
* tab-width: 4
|
|
* c-basic-offset: 4
|
|
* End:
|
|
* vim600: sw=4 ts=4 tw=78 fdm=marker
|
|
* vim: sw=4 ts=4 tw=78
|
|
*/
|