Remove all instances of the word "iff"

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

diff --git a/includes/HashRing.php b/includes/HashRing.php
index 227a287..930f8c0 100644 (file)
--- a/includes/HashRing.php
+++ b/includes/HashRing.php
@@ -27,6 +27,8 @@
  * @since 1.22
  */
 class HashRing {
+       /** @var Array (location => weight) */
+       protected $sourceMap = array();
        /** @var Array (location => (start, end)) */
        protected $ring = array();
 
@@ -36,10 +38,11 @@ class HashRing {
         * @param array $map (location => weight)
         */
        public function __construct( array $map ) {
-               $sum = array_sum( $map );
-               if ( !count( $map ) || $sum <= 0 ) {
+               $map = array_filter( $map, function( $w ) { return $w > 0; } );
+               if ( !count( $map ) ) {
                        throw new MWException( "Ring is empty or all weights are zero." );
                }
+               $this->sourceMap = $map;
                // Sort the locations based on the hash of their names
                $hashes = array();
                foreach ( $map as $location => $weight ) {
@@ -49,6 +52,7 @@ class HashRing {
                        return strcmp( $hashes[$a], $hashes[$b] );
                } );
                // Fit the map to weight-proportionate one with a space of size RING_SIZE
+               $sum = array_sum( $map );
                $standardMap = array();
                foreach ( $map as $location => $weight ) {
                        $standardMap[$location] = (int)floor( $weight / $sum * self::RING_SIZE );
@@ -111,4 +115,28 @@ class HashRing {
                }
                return $locations;
        }
+
+       /**
+        * Get the map of locations to weight (ignores 0-weight items)
+        *
+        * @return array
+        */
+       public function getLocationWeights() {
+               return $this->sourceMap;
+       }
+
+       /**
+        * Get a new hash ring with a location removed from the ring
+        *
+        * @param string $location
+        * @return HashRing|bool Returns false if no non-zero weighted spots are left
+        */
+       public function newWithoutLocation( $location ) {
+               $map = $this->sourceMap;
+               unset( $map[$location] );
+               if ( count( $map ) ) {
+                       return new self( $map );
+               }
+               return false;
+       }
 }