local: Add 'mopidy scan' command via extension sub-commands.

mopidy/backends/local/__init__.py

@@ -36,3 +36,7 @@ class Extension(ext.Extension):
     def get_library_updaters(self):
         from .library import LocalLibraryUpdateProvider
         return [LocalLibraryUpdateProvider]
+
+    def get_sub_commands(self):
+        from .scan import ScanSubCommand
+        return [ScanSubCommand]

mopidy/backends/local/scan.py

@@ -0,0 +1,105 @@
+from __future__ import unicode_literals
+
+import logging
+import os
+import time
+
+from mopidy import exceptions
+from mopidy.audio import scan
+from mopidy.backends import base
+from mopidy.utils import path
+
+logger = logging.getLogger('mopidy.backends.local.scan')
+
+
+class ScanSubCommand(base.BaseSubCommandProvider):
+    name = b'scan'
+    help = b'scan local media files'
+
+    def run(self, args, config, extensions):
+        media_dir = config['local']['media_dir']
+        scan_timeout = config['local']['scan_timeout']
+        excluded_file_extensions = config['local']['excluded_file_extensions']
+
+        updaters = {}
+        for e in extensions:
+            for updater_class in e.get_library_updaters():
+                if updater_class and 'local' in updater_class.uri_schemes:
+                    updaters[e.ext_name] = updater_class
+
+        if not updaters:
+            logging.error('No usable library updaters found.')
+            return 1
+        elif len(updaters) > 1:
+            logging.error('More than one library updater found. '
+                          'Provided by: %s', ', '.join(updaters.keys()))
+            return 1
+
+        local_updater = updaters.values()[0](config)
+
+        uris_library = set()
+        uris_update = set()
+        uris_remove = set()
+
+        logging.info('Checking tracks from library.')
+        for track in local_updater.load():
+            try:
+                # TODO: convert local to file uri / path
+                stat = os.stat(path.uri_to_path(track.uri))
+                if int(stat.st_mtime) > track.last_modified:
+                    uris_update.add(track.uri)
+                uris_library.add(track.uri)
+            except OSError:
+                logging.debug('Missing file %s', track.uri)
+                uris_remove.add(track.uri)
+
+        logging.info('Removing %d moved or deleted tracks.', len(uris_remove))
+        for uri in uris_remove:
+            local_updater.remove(uri)
+
+        logging.info('Checking %s for new or modified tracks.', media_dir)
+        for uri in path.find_uris(config['local']['media_dir']):
+            file_extension = os.path.splitext(path.uri_to_path(uri))[1]
+            if file_extension in excluded_file_extensions:
+                logging.debug('Skipped %s: File extension excluded.', uri)
+                continue
+
+            if uri not in uris_library:
+                uris_update.add(uri)
+
+        logging.info('Found %d new or modified tracks.', len(uris_update))
+        logging.info('Scanning new and modified tracks.')
+
+        scanner = scan.Scanner(scan_timeout)
+        progress = Progress(len(uris_update))
+
+        for uri in sorted(uris_update):
+            try:
+                data = scanner.scan(uri)
+                track = scan.audio_data_to_track(data)
+                local_updater.add(track)
+                logging.debug('Added %s', track.uri)
+            except exceptions.ScannerError as error:
+                logging.warning('Failed %s: %s', uri, error)
+
+            progress.increment()
+
+        logging.info('Commiting changes.')
+        local_updater.commit()
+        return 0
+
+
+# TODO: move to utils?
+class Progress(object):
+    def __init__(self, total):
+        self.count = 0
+        self.total = total
+        self.start = time.time()
+
+    def increment(self):
+        self.count += 1
+        if self.count % 1000 == 0 or self.count == self.total:
+            duration = time.time() - self.start
+            remainder = duration / self.count * (self.total - self.count)
+            logging.info('Scanned %d of %d files in %ds, ~%ds left.',
+                         self.count, self.total, duration, remainder)