Cache API: Introduce wp_cache_get_multi().

Many caching backend have support for multiple gets in a single request. This brings that support to core, with a compatability fallback that will loop over requests if needed.

Fixes: #20875.
Props: nacin, tollmanz, wonderboymusic, ryan, jeremyfelt, spacedmonkey, boonebgorges, dd32, rmccue, ocean90, jipmoors, johnjamesjacoby, tillkruess, donmhico, davidbaumwald, SergeyBiryukov, whyisjake.



git-svn-id: https://develop.svn.wordpress.org/trunk@47938 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/cache.php

@@ -126,6 +126,24 @@ function wp_cache_get( $key, $group = '', $force = false, &$found = null ) {
 	return $wp_object_cache->get( $key, $group, $force, $found );
 }
 
+/**
+ * Gets multiple values from cache in one call.
+ *
+ * @since 5.5.0
+ * @see WP_Object_Cache::get_multiple()
+ *
+ * @param array       $keys   Array of keys to get from group.
+ * @param string      $group  Optional. Where the cache contents are grouped. Default empty.
+ * @param bool        $force  Optional. Whether to force an update of the local cache from the persistent
+ *                            cache. Default false.
+ * @return array|bool Array of values.
+ */
+function wp_cache_get_multiple( $keys, $group = '', $force = false ) {
+	global $wp_object_cache;
+
+	return $wp_object_cache->get_multiple( $keys, $group, $force );
+}
+
 /**
  * Increment numeric cache item's value
  *