}
-static inline php_uint32 randomMT(void)
+static inline php_uint32 randomMT(TSRMLS_D)
{
php_uint32 y;
- TSRMLS_FETCH();
if(--BG(left) < 0)
return(reloadMT(TSRMLS_C));
Seeds random number generator */
PHP_FUNCTION(srand)
{
- pval **arg;
+ zval **seed;
- if (ZEND_NUM_ARGS() != 1 || zend_get_parameters_ex(1, &arg) == FAILURE) {
+ if (ZEND_NUM_ARGS() != 1 ||
+ zend_get_parameters_ex(1, &seed) == FAILURE) {
WRONG_PARAM_COUNT;
}
- convert_to_long_ex(arg);
- php_srand((*arg)->value.lval);
+ convert_to_long_ex(seed);
+
+ php_srand(Z_LVAL_PP(seed));
}
/* }}} */
Seeds Mersenne Twister random number generator */
PHP_FUNCTION(mt_srand)
{
- pval **arg;
+ zval **seed;
- if (ZEND_NUM_ARGS() != 1 || zend_get_parameters_ex(1, &arg) == FAILURE) {
+ if (ZEND_NUM_ARGS() != 1 ||
+ zend_get_parameters_ex(1, &seed) == FAILURE) {
WRONG_PARAM_COUNT;
}
- convert_to_long_ex(arg);
- seedMT((*arg)->value.lval TSRMLS_CC);
+ convert_to_long_ex(seed);
+
+ seedMT(Z_LVAL_PP(seed) TSRMLS_CC);
}
/* }}} */
+
+/*
+ * 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
+ # artifically 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(__n, __min, __max) \
+ (__min) + (int)((double)(__max) - (__min) + 1.0) * ((__n) / (PHP_RAND_MAX + 1.0))
+
/* {{{ proto int rand([int min, int max])
Returns a random number */
PHP_FUNCTION(rand)
{
- pval **p_min=NULL, **p_max=NULL;
-
- switch (ZEND_NUM_ARGS()) {
- case 0:
- break;
- case 2:
- if (zend_get_parameters_ex(2, &p_min, &p_max)==FAILURE) {
- RETURN_FALSE;
- }
- convert_to_long_ex(p_min);
- convert_to_long_ex(p_max);
- if ((*p_max)->value.lval-(*p_min)->value.lval < 0) {
- php_error(E_WARNING, "rand(): Invalid range: %ld..%ld", (*p_min)->value.lval, (*p_max)->value.lval);
- } else if ((*p_max)->value.lval-(*p_min)->value.lval > PHP_RAND_MAX){
- php3_error(E_WARNING, "rand(): Invalid range: %ld..%ld", (*p_min)->value.lval, (*p_max)->value.lval);
- }
- break;
- default:
- WRONG_PARAM_COUNT;
- break;
- }
-
- return_value->type = IS_LONG;
+ zval **min;
+ zval **max;
+ long number;
+ int argc = ZEND_NUM_ARGS();
- return_value->value.lval = php_rand();
+ if (argc != 0 && argc != 2 ||
+ zend_get_parameters_ex(argc, &min, &max) == FAILURE) {
+ WRONG_PARAM_COUNT;
+ }
- /*
- * 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
- # artifically 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
- */
- if (p_min && p_max) { /* implement range */
- return_value->value.lval = (*p_min)->value.lval +
- (int)((double)((*p_max)->value.lval - (*p_min)->value.lval + 1.0) * return_value->value.lval/(PHP_RAND_MAX+1.0));
+ number = php_rand();
+ if (argc == 2) {
+ number = RAND_RANGE(number, Z_LVAL_PP(min), Z_LVAL_PP(max));
}
+
+ RETURN_LONG(number);
}
/* }}} */
Returns a random number from Mersenne Twister */
PHP_FUNCTION(mt_rand)
{
- pval **p_min=NULL, **p_max=NULL;
-
- switch (ZEND_NUM_ARGS()) {
- case 0:
- break;
- case 2:
- if (zend_get_parameters_ex(2, &p_min, &p_max)==FAILURE) {
- RETURN_FALSE;
- }
- convert_to_long_ex(p_min);
- convert_to_long_ex(p_max);
- if ((*p_max)->value.lval-(*p_min)->value.lval <= 0) {
- php_error(E_WARNING, "mt_rand(): Invalid range: %ld..%ld", (*p_min)->value.lval, (*p_max)->value.lval);
- }else if ((*p_max)->value.lval-(*p_min)->value.lval > MT_RAND_MAX){
- php3_error(E_WARNING, "mt_rand(): Invalid range: %ld..%ld", (*p_min)->value.lval, (*p_max)->value.lval);
- }
- break;
- default:
- WRONG_PARAM_COUNT;
- break;
+ zval **min;
+ zval **max;
+ long number;
+ int argc = ZEND_NUM_ARGS();
+
+ if (argc != 0 && argc != 2 ||
+ zend_get_parameters_ex(argc, &min, &max) == FAILURE) {
+ WRONG_PARAM_COUNT;
}
-
- return_value->type = IS_LONG;
+
/*
* Melo: hmms.. randomMT() returns 32 random bits...
* Yet, the previous php_rand only returns 31 at most.
* Update:
* I talked with Cokus via email and it won't ruin the algorithm
*/
- return_value->value.lval = (long)(randomMT() >> 1);
-
- if (p_min && p_max) { /* implement range */
- return_value->value.lval = (*p_min)->value.lval +
- (long)((double)((*p_max)->value.lval - (*p_min)->value.lval + 1.0) * return_value->value.lval/(MT_RAND_MAX+1.0));
+ number = (long) (randomMT(TSRMLS_C) >> 1);
+ if (argc == 2) {
+ number = RAND_RANGE(number, Z_LVAL_PP(min), Z_LVAL_PP(max));
}
+
+ RETURN_LONG(number);
}
/* }}} */
WRONG_PARAM_COUNT;
}
- return_value->type = IS_LONG;
- return_value->value.lval = PHP_RAND_MAX;
+ RETURN_LONG(PHP_RAND_MAX);
}
/* }}} */
WRONG_PARAM_COUNT;
}
- return_value->type = IS_LONG;
/*
* Melo: it could be 2^^32 but we only use 2^^31 to maintain
* compatibility with the previous php_rand
*/
- return_value->value.lval = MT_RAND_MAX; /* 2^^31 */
+ RETURN_LONG(MT_RAND_MAX); /* 2^^31 */
}
/* }}} */
* tab-width: 4
* c-basic-offset: 4
* End:
- * vim600: sw=4 ts=4 tw=78 fdm=marker
- * vim<600: sw=4 ts=4 tw=78
+ * vim600: noet sw=4 ts=4 tw=78 fdm=marker
+ * vim<600: noet sw=4 ts=4 tw=78
*/
projects / php / commitdiff