mwdocgen: support multiple --file values

[lhc/web/wiklou.git] / includes / ArrayUtils.php

diff --git a/includes/ArrayUtils.php b/includes/ArrayUtils.php
index d1b72a0..985271f 100644 (file)
--- a/includes/ArrayUtils.php
+++ b/includes/ArrayUtils.php
@@ -21,7 +21,7 @@ class ArrayUtils {
         *     various consistent hash implementations that existed before this
         *     function was introduced.
         */
-       static function consistentHashSort( &$array, $key, $separator = "\000" ) {
+       public static function consistentHashSort( &$array, $key, $separator = "\000" ) {
                $hashes = array();
                foreach ( $array as $elt ) {
                        $hashes[$elt] = md5( $elt . $separator . $key );
@@ -30,4 +30,40 @@ class ArrayUtils {
                        return strcmp( $hashes[$a], $hashes[$b] );
                } );
        }
+
+       /**
+        * Given an array of non-normalised probabilities, this function will select
+        * an element and return the appropriate key
+        *
+        * @param $weights array
+        *
+        * @return bool|int|string
+        */
+       public static function pickRandom( $weights ) {
+               if ( !is_array( $weights ) || count( $weights ) == 0 ) {
+                       return false;
+               }
+
+               $sum = array_sum( $weights );
+               if ( $sum == 0 ) {
+                       # No loads on any of them
+                       # In previous versions, this triggered an unweighted random selection,
+                       # but this feature has been removed as of April 2006 to allow for strict
+                       # separation of query groups.
+                       return false;
+               }
+               $max = mt_getrandmax();
+               $rand = mt_rand( 0, $max ) / $max * $sum;
+
+               $sum = 0;
+               foreach ( $weights as $i => $w ) {
+                       $sum += $w;
+                       # Do not return keys if they have 0 weight.
+                       # Note that the "all 0 weight" case is handed above
+                       if ( $w > 0 && $sum >= $rand ) {
+                               break;
+                       }
+               }
+               return $i;
+       }
 }