* Cache result of FSStore._fsspec_installed (#1581)

Prevent runtime-overhead in doing this check multiple times

Author: ph03

docs/release.rst

@@ -43,6 +43,9 @@ Docs
 Maintenance
 ~~~~~~~~~~~
 
+* Cache result of ``FSStore._fsspec_installed()``.
+  By :user:`Janick Martinez Esturo <ph03>` :issue:`1581`.
+
 * Extend copyright notice to 2023.
   By :user:`Jack Kelly <JackKelly>` :issue:`1528`.
 

zarr/storage.py

@@ -28,6 +28,7 @@
 import zipfile
 from collections import OrderedDict
 from collections.abc import MutableMapping
+from functools import lru_cache
 from os import scandir
 from pickle import PicklingError
 from threading import Lock, RLock
@@ -1540,6 +1541,7 @@ def clear(self):
         self.map.clear()
 
     @classmethod
+    @lru_cache(maxsize=None)
     def _fsspec_installed(cls):
         """Returns true if fsspec is installed"""
         import importlib.util