From b26ce25719f9478cbc02cd0f0ec7e63c50ec62d3 Mon Sep 17 00:00:00 2001
From: grillazz <the@grillazz.com>
Date: Fri, 20 Dec 2024 18:06:21 +0100
Subject: [PATCH] add singleton meta with no args

---
 app/utils/singleton.py | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/app/utils/singleton.py b/app/utils/singleton.py
index 0c94176..85df17e 100644
--- a/app/utils/singleton.py
+++ b/app/utils/singleton.py
@@ -16,3 +16,21 @@ class SingletonMeta(type):
                 instance = super().__call__(*args, **kwargs)
                 cls._instances[cls] = instance
         return cls._instances[cls]
+
+
+class SingletonMetaNoArgs(type):
+    """
+    Singleton metaclass for classes without parameters on constructor,
+    for compatibility with FastApi Depends() function.
+    """
+
+    _instances = {}
+
+    _lock: Lock = Lock()
+
+    def __call__(cls):
+        with cls._lock:
+            if cls not in cls._instances:
+                instance = super().__call__()
+                cls._instances[cls] = instance
+        return cls._instances[cls]
\ No newline at end of file