Cache metadata in an LRU cache instead of fetching it from disk everytime

requirements.txt

@@ -11,3 +11,4 @@ netaddr
 watchdog
 sarge
 netifaces
+pylru

src/octoprint/filemanager/storage.py

@@ -8,6 +8,7 @@ __copyright__ = "Copyright (C) 2014 The OctoPrint Project - Released under terms
 
 import logging
 import os
+import pylru
 
 import octoprint.filemanager
 
@@ -89,6 +90,8 @@ class LocalFileStorage(StorageInterface):
 		import threading
 		self._metadata_lock = threading.Lock()
 
+		self._metadata_cache = pylru.lrucache(10)
+
 	@property
 	def analysis_backlog(self):
 		for entry in self._analysis_backlog_generator():
@@ -764,6 +767,9 @@ class LocalFileStorage(StorageInterface):
 		return path
 
 	def _get_metadata(self, path):
+		if path in self._metadata_cache:
+			return self._metadata_cache[path]
+
 		metadata_path = os.path.join(path, ".metadata.yaml")
 		if os.path.exists(metadata_path):
 			with self._metadata_lock:
@@ -784,4 +790,6 @@ class LocalFileStorage(StorageInterface):
 					import yaml
 					yaml.safe_dump(metadata, stream=f, default_flow_style=False, indent="  ", allow_unicode=True)
 				except:
-					self._logger.exception("Error while writing .metadata.yaml to {path}".format(**locals()))
+					self._logger.exception("Error while writing .metadata.yaml to {path}".format(**locals()))
+				else:
+					self._metadata_cache[path] = metadata