Memoise Key::getThumbnail

kelvinmo · Aug 27, 2023 · 305ea66 · 305ea66
1 parent 717c82e
commit 305ea66
Showing 1 changed file with 14 additions and 8 deletions.
diff --git a/src/SimpleJWT/Keys/Key.php b/src/SimpleJWT/Keys/Key.php
@@ -271,14 +271,20 @@ abstract protected function getThumbnailMembers();
     /**
      * {@inheritdoc}
      */
-    public function getThumbnail() {
-        $members = $this->getThumbnailMembers();
-        $signing = [];
-        foreach ($members as $member) $signing[$member] = strval($this->data[$member]);
-        ksort($signing);
-        $hash_input = json_encode($signing);
-        if ($hash_input == false) throw new KeyException('Cannot generate thumbnail');
-        return Util::base64url_encode(hash('sha256', $hash_input, true));
+    public final function getThumbnail() {
+        static $thumbnail = null;
+
+        if ($thumbnail == null) {
+            $members = $this->getThumbnailMembers();
+            $signing = [];
+            foreach ($members as $member) $signing[$member] = strval($this->data[$member]);
+            ksort($signing);
+            $hash_input = json_encode($signing);
+            if ($hash_input == false) throw new KeyException('Cannot generate thumbnail');
+            $thumbnail = Util::base64url_encode(hash('sha256', $hash_input, true));
+        }
+
+        return $thumbnail;
     }
 
     /**