Add docstring to readthedocs.core.views.serve._serve_file

Author: humitos

readthedocs/core/views/serve.py

@@ -139,6 +139,23 @@ def _serve_401(request, project):
 
 
 def _serve_file(request, filename, basepath):
+    """
+    Serve media file via Django or NGINX based on ``PYTHON_MEDIA``.
+
+    When using ``PYTHON_MEDIA=True`` (or when ``DEBUG=True``) the file is served
+    by ``django.views.static.serve`` function.
+
+    On the other hand, when ``PYTHON_MEDIA=False`` the file is served by using
+    ``X-Accel-Redirect`` header for NGINX to take care of it and serve the file.
+
+    :param request: Django HTTP request
+    :param filename: path to the filename to be served relative to ``basepath``
+    :param basepath: base path to prepend to the filename
+
+    :returns: Django HTTP response object
+
+    :raises: ``Http404`` on ``UnicodeEncodeError``
+    """
     # Serve the file from the proper location
     if settings.DEBUG or getattr(settings, 'PYTHON_MEDIA', False):
         # Serve from Python