file: Don't scan files on browsing

Fixes #1260

docs/changelog.rst

@@ -21,6 +21,11 @@ Bug fix release.
   with a limited set of environment variables. (Fixes: :issue:`1249`, PR:
   :issue:`1255`)
 
+- File: When browsing files, we no longer scan the files to check if they're
+  playable. This makes browsing of the file hierarchy instant for HTTP clients,
+  which do no scanning of the files' metadata, and a bit faster for MPD
+  clients, which no longer scan the files twice.
+
 - Audio: Fix timeout handling in scanner. This regression caused timeouts to
   expire before it should, causing scans to fail.
 

mopidy/file/library.py

@@ -71,7 +71,7 @@ class FileLibraryProvider(backend.LibraryProvider):
             name = dir_entry.decode(FS_ENCODING, 'replace')
             if os.path.isdir(child_path):
                 result.append(models.Ref.directory(name=name, uri=uri))
-            elif os.path.isfile(child_path) and self._is_audio_file(uri):
+            elif os.path.isfile(child_path):
                 result.append(models.Ref.track(name=name, uri=uri))
 
         result.sort(key=operator.attrgetter('name'))
@@ -134,18 +134,6 @@ class FileLibraryProvider(backend.LibraryProvider):
                 name=media_dir['name'],
                 uri=path.path_to_uri(media_dir['path']))
 
-    def _is_audio_file(self, uri):
-        try:
-            result = self._scanner.scan(uri)
-            if result.playable:
-                logger.debug('Playable file: %s', result.uri)
-            else:
-                logger.debug('Unplayable file: %s (not audio)', result.uri)
-            return result.playable
-        except exceptions.ScannerError as e:
-            logger.debug('Unplayable file: %s (%s)', uri, e)
-            return False
-
     def _is_in_basedir(self, local_path):
         return any(
             path.is_path_inside_base_dir(local_path, media_dir['path'])