made it optional & updated docs

Author: Rishab87

docs/source/developers/contents.rst

@@ -61,7 +61,11 @@ Models may contain the following entries:
 +--------------------+------------+-------------------------------+
 | **item_count**     | int or     | The number of items in a      |
 |                    | ``None``   | directory, or ``None`` for    |
-|                    |            | files and notebooks.          |
+|                    |            | files and notebooks. This     |
+|                    |            | field is None by default      |
+|                    |            | unless                        |
+|                    |            | ``count_directory_items`` is  |
+|                    |            | set to True.                  |
 +--------------------+------------+-------------------------------+
 | **format**         | unicode or | The format of ``content``,    |
 |                    | ``None``   | if any. (:ref:`See            |
@@ -115,6 +119,8 @@ model. There are three model types: **notebook**, **file**, and **directory**.
       models representing the entities in the directory.
     - The ``hash`` field is always ``None``.
     - The ``item_count`` field contains the number of items in the directory
+      which is False by default unless  ``count_directory_items`` is set to
+      True.
 
 .. note::
 

jupyter_server/services/contents/filemanager.py

@@ -119,6 +119,12 @@ def _checkpoints_class_default(self):
         if safe. And if ``delete_to_trash`` is True, the directory won't be deleted.""",
     )
 
+    count_directory_items = Bool(
+        False,
+        config=True,
+        help="Whether to count items in directories. Disable for better performance with large/remote directories.",
+    ).tag(config=True)
+
     @default("files_handler_class")
     def _files_handler_class_default(self):
         return AuthenticatedFileHandler
@@ -296,16 +302,21 @@ def _dir_model(self, path, content=True):
         model["size"] = None
         os_dir = self._get_os_path(path)
         dir_contents = os.listdir(os_dir)
-        filtered_count = 0
-        for name in dir_contents:
-            try:
-                os_path = os.path.join(os_dir, name)
-                if self.should_list(name) and (self.allow_hidden or not is_file_hidden(os_path)):
-                    filtered_count += 1
-            except OSError as e:
-                self.log.warning("Error accessing %s: %s", os.path.join(os_dir, name), e)
 
-        model["item_count"] = filtered_count
+        if self.count_directory_items:
+            filtered_count = 0
+            for name in dir_contents:
+                try:
+                    os_path = os.path.join(os_dir, name)
+                    if self.should_list(name) and (
+                        self.allow_hidden or not is_file_hidden(os_path)
+                    ):
+                        filtered_count += 1
+                except OSError as e:
+                    self.log.warning("Error accessing %s: %s", os.path.join(os_dir, name), e)
+
+            model["item_count"] = filtered_count
+
         if content:
             model["content"] = contents = []
             for name in os.listdir(os_dir):
@@ -779,16 +790,21 @@ async def _dir_model(self, path, content=True):
         model["size"] = None
         os_dir = self._get_os_path(path)
         dir_contents = await run_sync(os.listdir, os_dir)
-        filtered_count = 0
-        for name in dir_contents:
-            try:
-                os_path = os.path.join(os_dir, name)
-                if self.should_list(name) and (self.allow_hidden or not is_file_hidden(os_path)):
-                    filtered_count += 1
-            except OSError as e:
-                self.log.warning("Error accessing %s: %s", os.path.join(os_dir, name), e)
 
-        model["item_count"] = filtered_count
+        if self.count_directory_items:
+            filtered_count = 0
+            for name in dir_contents:
+                try:
+                    os_path = os.path.join(os_dir, name)
+                    if self.should_list(name) and (
+                        self.allow_hidden or not is_file_hidden(os_path)
+                    ):
+                        filtered_count += 1
+                except OSError as e:
+                    self.log.warning("Error accessing %s: %s", os.path.join(os_dir, name), e)
+
+            model["item_count"] = filtered_count
+
         if content:
             model["content"] = contents = []
             for name in dir_contents:

tests/services/contents/test_manager.py

@@ -549,6 +549,7 @@ async def test_modified_date(jp_contents_manager):
 
 async def test_get(jp_contents_manager):
     cm = jp_contents_manager
+    cm.count_directory_items = True
     # Create a notebook
     model = await ensure_async(cm.new_untitled(type="notebook"))
     name = model["name"]