Allow passing existing redis connections to MD_STD_CACHE

src/MD_STD_CACHE.php

@@ -57,16 +57,23 @@ final class MD_STD_CACHE {
      *
      * @param string     $redisKey Key to cache by in redis.
      * @param integer    $expiry   Expiration time in seconds.
+     * @param Redis|null $redis    Redis connection already opened, if one exists.
+     *                             If this parameter is not provided, a separate
+     *                             redis connection is opened for this function.
      *
      * @return string
      */
-    public static function serve_page_through_redis_cache(string $redisKey, int $expiry = 3600):string {
+    public static function serve_page_through_redis_cache(string $redisKey, int $expiry = 3600, ?Redis $redis = null):string {
 
         if (PHP_SAPI === 'cli') {
             return '';
         }
 
+        if ($redis === null) {
             $redis = self::open_redis_default();
+            $closeRedis = true;
+        }
+        else $closeRedis = false;
 
         if ($redis->ping() !== false) {
 
@@ -94,7 +101,10 @@ final class MD_STD_CACHE {
             }
 
         }
+
+        if ($closeRedis === true) {
             $redis->close();
+        }
 
         return '';