Call pre_save_hook only on first chunk of large files (#716)

* Call pre_save_hook only on first chunk of large files

* Include chunk number in debug message

Author: davidbrochart

jupyter_server/services/contents/filemanager.py

@@ -775,15 +775,16 @@ async def save(self, model, path=""):
         """Save the file model and return the model with no content."""
         path = path.strip("/")
 
-        os_path = self._get_os_path(path)
-        self.log.debug("Saving %s", os_path)
         self.run_pre_save_hook(model=model, path=path)
 
         if "type" not in model:
             raise web.HTTPError(400, "No file type provided")
         if "content" not in model and model["type"] != "directory":
             raise web.HTTPError(400, "No file content provided")
 
+        os_path = self._get_os_path(path)
+        self.log.debug("Saving %s", os_path)
+
         try:
             if model["type"] == "notebook":
                 nb = nbformat.from_dict(model["content"])

jupyter_server/services/contents/largefilemanager.py

@@ -18,7 +18,8 @@ def save(self, model, path=""):
         if chunk is not None:
             path = path.strip("/")
 
-            self.run_pre_save_hook(model=model, path=path)
+            if chunk == 1:
+                self.run_pre_save_hook(model=model, path=path)
 
             if "type" not in model:
                 raise web.HTTPError(400, "No file type provided")
@@ -31,7 +32,10 @@ def save(self, model, path=""):
                 raise web.HTTPError(400, "No file content provided")
 
             os_path = self._get_os_path(path)
-            self.log.debug("Saving %s", os_path)
+            if chunk == -1:
+                self.log.debug(f"Saving last chunk of file {os_path}")
+            else:
+                self.log.debug(f"Saving chunk {chunk} of file {os_path}")
 
             try:
                 if chunk == 1:
@@ -89,9 +93,8 @@ async def save(self, model, path=""):
         if chunk is not None:
             path = path.strip("/")
 
-            os_path = self._get_os_path(path)
-            self.log.debug("Saving %s", os_path)
-            self.run_pre_save_hook(model=model, path=path)
+            if chunk == 1:
+                self.run_pre_save_hook(model=model, path=path)
 
             if "type" not in model:
                 raise web.HTTPError(400, "No file type provided")
@@ -103,6 +106,12 @@ async def save(self, model, path=""):
             if "content" not in model and model["type"] != "directory":
                 raise web.HTTPError(400, "No file content provided")
 
+            os_path = self._get_os_path(path)
+            if chunk == -1:
+                self.log.debug(f"Saving last chunk of file {os_path}")
+            else:
+                self.log.debug(f"Saving chunk {chunk} of file {os_path}")
+
             try:
                 if chunk == 1:
                     await super(AsyncLargeFileManager, self)._save_file(