/* +----------------------------------------------------------------------+ | PHP Version 7 | +----------------------------------------------------------------------+ | Copyright (c) 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. | +----------------------------------------------------------------------+ | Authors: Rasmus Lerdorf <rasmus@php.net> | | Zeev Suraski <zeev@php.net> | | Pedro Melo <melo@ip.pt> | | Sterling Hughes <sterling@php.net> | | | | Based on code from: Shawn Cokus <Cokus@math.washington.edu> | +----------------------------------------------------------------------+ */ #ifndef PHP_RAND_H #define PHP_RAND_H #include "php_lcg.h" #include "php_mt_rand.h" /* System Rand functions */ #ifndef RAND_MAX #define RAND_MAX PHP_MT_RAND_MAX #endif #define PHP_RAND_MAX PHP_MT_RAND_MAX /* * 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 * Let n = the random number and n' = the mapped random number * * Then we have: n' = a + n(b-a)/M * * We have a problem here in that only n==M will get mapped to b which # means the chances of getting b is much much less than getting any of # the other values in the range. We can fix this by increasing our range # artificially and using: # # n' = a + n(b-a+1)/M * # Now we only have a problem if n==M which would cause us to produce a # number of b+1 which would be bad. So we bump M up by one to make sure # this will never happen, and the final algorithm looks like this: # # n' = a + n(b-a+1)/(M+1) * * -RL */ #define RAND_RANGE_BADSCALING(__n, __min, __max, __tmax) \ (__n) = (__min) + (zend_long) ((double) ( (double) (__max) - (__min) + 1.0) * ((__n) / ((__tmax) + 1.0))) #ifdef PHP_WIN32 #define GENERATE_SEED() (((zend_long) (time(0) * GetCurrentProcessId())) ^ ((zend_long) (1000000.0 * php_combined_lcg()))) #else #define GENERATE_SEED() (((zend_long) (time(0) * getpid())) ^ ((zend_long) (1000000.0 * php_combined_lcg()))) #endif PHPAPI void php_srand(zend_long seed); PHPAPI zend_long php_rand(void); #endif /* PHP_RAND_H */
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base64.h | File | 3.8 KB | 0644 |
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basic_functions.h | File | 7.71 KB | 0644 |
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crc32.h | File | 4.64 KB | 0644 |
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credits.h | File | 1.67 KB | 0644 |
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credits_ext.h | File | 5.25 KB | 0644 |
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credits_sapi.h | File | 835 B | 0644 |
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crypt_blowfish.h | File | 1.01 KB | 0644 |
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crypt_freesec.h | File | 662 B | 0644 |
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css.h | File | 1.19 KB | 0644 |
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cyr_convert.h | File | 1.22 KB | 0644 |
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datetime.h | File | 1.34 KB | 0644 |
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dl.h | File | 1.59 KB | 0644 |
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exec.h | File | 1.68 KB | 0644 |
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file.h | File | 4.63 KB | 0644 |
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flock_compat.h | File | 2.06 KB | 0644 |
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fsock.h | File | 1.42 KB | 0644 |
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head.h | File | 1.85 KB | 0644 |
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hrtime.h | File | 2.48 KB | 0644 |
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html.h | File | 2.62 KB | 0644 |
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html_tables.h | File | 472.41 KB | 0644 |
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info.h | File | 22.6 KB | 0644 |
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md5.h | File | 2.1 KB | 0644 |
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microtime.h | File | 1.32 KB | 0644 |
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pack.h | File | 1.24 KB | 0644 |
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pageinfo.h | File | 1.42 KB | 0644 |
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php_array.h | File | 4.41 KB | 0644 |
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php_assert.h | File | 1.38 KB | 0644 |
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php_browscap.h | File | 1.28 KB | 0644 |
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php_crypt.h | File | 1.54 KB | 0644 |
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php_crypt_r.h | File | 1.99 KB | 0644 |
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php_dir.h | File | 1.66 KB | 0644 |
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php_dns.h | File | 2.96 KB | 0644 |
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php_ext_syslog.h | File | 1.46 KB | 0644 |
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php_filestat.h | File | 3.1 KB | 0644 |
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php_fopen_wrappers.h | File | 1.94 KB | 0644 |
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php_ftok.h | File | 1.22 KB | 0644 |
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php_http.h | File | 1.62 KB | 0644 |
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php_image.h | File | 2.37 KB | 0644 |
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php_incomplete_class.h | File | 2.24 KB | 0644 |
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php_iptc.h | File | 1.23 KB | 0644 |
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php_lcg.h | File | 1.48 KB | 0644 |
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php_link.h | File | 1.33 KB | 0644 |
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php_mail.h | File | 2.37 KB | 0644 |
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php_math.h | File | 4.65 KB | 0644 |
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php_metaphone.h | File | 1.2 KB | 0644 |
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php_mt_rand.h | File | 1.96 KB | 0644 |
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php_net.h | File | 1.32 KB | 0644 |
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php_password.h | File | 3.07 KB | 0644 |
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php_rand.h | File | 3.14 KB | 0644 |
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php_random.h | File | 2.07 KB | 0644 |
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php_smart_string.h | File | 1.28 KB | 0644 |
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php_smart_string_public.h | File | 1.29 KB | 0644 |
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php_standard.h | File | 2.24 KB | 0644 |
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php_string.h | File | 5.94 KB | 0644 |
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php_type.h | File | 1.62 KB | 0644 |
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php_uuencode.h | File | 1.38 KB | 0644 |
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php_var.h | File | 3.61 KB | 0644 |
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php_versioning.h | File | 1.36 KB | 0644 |
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proc_open.h | File | 1.74 KB | 0644 |
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quot_print.h | File | 1.45 KB | 0644 |
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scanf.h | File | 2.24 KB | 0644 |
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sha1.h | File | 1.69 KB | 0644 |
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streamsfuncs.h | File | 2.73 KB | 0644 |
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uniqid.h | File | 1.23 KB | 0644 |
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url.h | File | 2.39 KB | 0644 |
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url_scanner_ex.h | File | 2.44 KB | 0644 |
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