bpd: support MPD 0.16 protocol and more clients

beets/util/bluelet.py

@@ -346,6 +346,10 @@ def kill_thread(coro):
                             exc.args[0] == errno.EPIPE:
                         # Broken pipe. Remote host disconnected.
                         pass
+                    elif isinstance(exc.args, tuple) and \
+                            exc.args[0] == errno.ECONNRESET:
+                        # Connection was reset by peer.
+                        pass
                     else:
                         traceback.print_exc()
                     # Abort the coroutine.

beetsplug/bpd/__init__.py

@@ -39,7 +39,7 @@
 from mediafile import MediaFile
 import six
 
-PROTOCOL_VERSION = '0.14.0'
+PROTOCOL_VERSION = '0.16.0'
 BUFSIZE = 1024
 
 HELLO = u'OK MPD %s' % PROTOCOL_VERSION
@@ -77,8 +77,8 @@
 SUBSYSTEMS = [
     u'update', u'player', u'mixer', u'options', u'playlist', u'database',
     # Related to unsupported commands:
-    # u'stored_playlist', u'output', u'subscription', u'sticker', u'message',
-    # u'partition',
+    u'stored_playlist', u'output', u'subscription', u'sticker', u'message',
+    u'partition',
 ]
 
 ITEM_KEYS_WRITABLE = set(MediaFile.fields()).intersection(Item._fields.keys())
@@ -412,6 +412,11 @@ def cmd_status(self, conn):
             current_id = self._item_id(self.playlist[self.current_index])
             yield u'song: ' + six.text_type(self.current_index)
             yield u'songid: ' + six.text_type(current_id)
+            if len(self.playlist) > self.current_index + 1:
+                # If there's a next song, report its index too.
+                next_id = self._item_id(self.playlist[self.current_index + 1])
+                yield u'nextsong: ' + six.text_type(self.current_index + 1)
+                yield u'nextsongid: ' + six.text_type(next_id)
 
         if self.error:
             yield u'error: ' + self.error
@@ -454,7 +459,8 @@ def cmd_setvol(self, conn, vol):
 
     def cmd_volume(self, conn, vol_delta):
         """Deprecated command to change the volume by a relative amount."""
-        raise BPDError(ERROR_SYSTEM, u'No mixer')
+        vol_delta = cast_arg(int, vol_delta)
+        return self.cmd_setvol(conn, self.volume + vol_delta)
 
     def cmd_crossfade(self, conn, crossfade):
         """Set the number of seconds of crossfading."""
@@ -577,23 +583,27 @@ def cmd_urlhandlers(self, conn):
         """Indicates supported URL schemes. None by default."""
         pass
 
-    def cmd_playlistinfo(self, conn, index=-1):
+    def cmd_playlistinfo(self, conn, index=None):
         """Gives metadata information about the entire playlist or a
         single track, given by its index.
         """
-        index = cast_arg(int, index)
-        if index == -1:
+        if index is None:
             for track in self.playlist:
                 yield self._item_info(track)
         else:
+            indices = self._parse_range(index, accept_single_number=True)
             try:
-                track = self.playlist[index]
+                tracks = [self.playlist[i] for i in indices]
             except IndexError:
                 raise ArgumentIndexError()
-            yield self._item_info(track)
+            for track in tracks:
+                yield self._item_info(track)
 
-    def cmd_playlistid(self, conn, track_id=-1):
-        return self.cmd_playlistinfo(conn, self._id_to_index(track_id))
+    def cmd_playlistid(self, conn, track_id=None):
+        if track_id is not None:
+            track_id = cast_arg(int, track_id)
+            track_id = self._id_to_index(track_id)
+        return self.cmd_playlistinfo(conn, track_id)
 
     def cmd_plchanges(self, conn, version):
         """Sends playlist changes since the given version.
@@ -624,7 +634,6 @@ def cmd_next(self, conn):
         """Advance to the next song in the playlist."""
         old_index = self.current_index
         self.current_index = self._succ_idx()
-        self._send_event('playlist')
         if self.consume:
             # TODO how does consume interact with single+repeat?
             self.playlist.pop(old_index)
@@ -645,7 +654,6 @@ def cmd_previous(self, conn):
         """Step back to the last song."""
         old_index = self.current_index
         self.current_index = self._prev_idx()
-        self._send_event('playlist')
         if self.consume:
             self.playlist.pop(old_index)
         if self.current_index < 0:
@@ -844,6 +852,9 @@ def run(self):
                     yield self.send(err.response())
                     break
                 continue
+            if line == u'noidle':
+                # When not in idle, this command sends no response.
+                continue
 
             if clist is not None:
                 # Command list already opened.
@@ -1094,6 +1105,8 @@ def __init__(self, library, host, port, password, ctrl_port, log):
         self.cmd_update(None)
         log.info(u'Server ready and listening on {}:{}'.format(
             host, port))
+        log.debug(u'Listening for control signals on {}:{}'.format(
+            host, ctrl_port))
 
     def run(self):
         self.player.run()
@@ -1111,30 +1124,38 @@ def _item_info(self, item):
         info_lines = [
             u'file: ' + item.destination(fragment=True),
             u'Time: ' + six.text_type(int(item.length)),
-            u'Title: ' + item.title,
-            u'Artist: ' + item.artist,
-            u'Album: ' + item.album,
-            u'Genre: ' + item.genre,
+            u'duration: ' + u'{:.3f}'.format(item.length),
+            u'Id: ' + six.text_type(item.id),
         ]
 
-        track = six.text_type(item.track)
-        if item.tracktotal:
-            track += u'/' + six.text_type(item.tracktotal)
-        info_lines.append(u'Track: ' + track)
-
-        info_lines.append(u'Date: ' + six.text_type(item.year))
-
         try:
             pos = self._id_to_index(item.id)
             info_lines.append(u'Pos: ' + six.text_type(pos))
         except ArgumentNotFoundError:
             # Don't include position if not in playlist.
             pass
 
-        info_lines.append(u'Id: ' + six.text_type(item.id))
+        for tagtype, field in self.tagtype_map.items():
+            info_lines.append(u'{}: {}'.format(
+                tagtype, six.text_type(getattr(item, field))))
 
         return info_lines
 
+    def _parse_range(self, items, accept_single_number=False):
+        """Convert a range of positions to a list of item info.
+        MPD specifies ranges as START:STOP (endpoint excluded) for some
+        commands. Sometimes a single number can be provided instead.
+        """
+        try:
+            start, stop = str(items).split(':', 1)
+        except ValueError:
+            if accept_single_number:
+                return [cast_arg(int, items)]
+            raise BPDError(ERROR_ARG, u'bad range syntax')
+        start = cast_arg(int, start)
+        stop = cast_arg(int, stop)
+        return range(start, stop)
+
     def _item_id(self, item):
         return item.id
 
@@ -1335,18 +1356,24 @@ def cmd_decoders(self, conn):
 
     tagtype_map = {
         u'Artist':          u'artist',
+        u'ArtistSort':      u'artist_sort',
         u'Album':           u'album',
         u'Title':           u'title',
         u'Track':           u'track',
         u'AlbumArtist':     u'albumartist',
         u'AlbumArtistSort': u'albumartist_sort',
-        # Name?
+        u'Label':           u'label',
         u'Genre':           u'genre',
         u'Date':            u'year',
+        u'OriginalDate':    u'original_year',
         u'Composer':        u'composer',
-        # Performer?
         u'Disc':            u'disc',
-        u'filename':        u'path',  # Suspect.
+        u'Comment':         u'comments',
+        u'MUSICBRAINZ_TRACKID':        u'mb_trackid',
+        u'MUSICBRAINZ_ALBUMID':        u'mb_albumid',
+        u'MUSICBRAINZ_ARTISTID':       u'mb_artistid',
+        u'MUSICBRAINZ_ALBUMARTISTID':  u'mb_albumartistid',
+        u'MUSICBRAINZ_RELEASETRACKID': u'mb_releasetrackid',
     }
 
     def cmd_tagtypes(self, conn):
@@ -1543,7 +1570,7 @@ def cmd_stop(self, conn):
     def cmd_seek(self, conn, index, pos):
         """Seeks to the specified position in the specified song."""
         index = cast_arg(int, index)
-        pos = cast_arg(int, pos)
+        pos = cast_arg(float, pos)
         super(Server, self).cmd_seek(conn, index, pos)
         self.player.seek(pos)
 

docs/changelog.rst

@@ -11,6 +11,12 @@ New features:
   (the MBID), and ``work_disambig`` (the disambiguation string).
   Thanks to :user:`dosoe`.
   :bug:`2580` :bug:`3272`
+* :doc:`/plugins/bpd`: BPD now supports most of the features of version 0.16
+  of the MPD protocol. This is enough to get it talking to more complicated
+  clients like ncmpcpp, but there are still some incompatibilities, largely due
+  to MPD commands we don't support yet. Let us know if you find an MPD client
+  that doesn't get along with BPD!
+  :bug:`3214` :bug:`800`
 
 Fixes:
 
@@ -20,6 +26,10 @@ Fixes:
   objects could seem to reuse values from earlier objects when they were
   missing a value for a given field. These values are now properly undefined.
   :bug:`2406`
+* :doc:`/plugins/bpd`: Seeking by fractions of a second now works as intended,
+  fixing crashes in MPD clients like mpDris2 on seek.
+  The ``playlistid`` command now works properly in its zero-argument form.
+  :bug:`3214`
 
 For plugin developers:
 

docs/plugins/bpd.rst

@@ -103,7 +103,7 @@ but doesn't support many advanced playback features.
 Differences from the real MPD
 -----------------------------
 
-BPD currently supports version 0.14 of `the MPD protocol`_, but several of the
+BPD currently supports version 0.16 of `the MPD protocol`_, but several of the
 commands and features are "pretend" implementations or have slightly different
 behaviour to their MPD equivalents. BPD aims to look enough like MPD that it
 can interact with the ecosystem of clients, but doesn't try to be
@@ -125,8 +125,7 @@ These are some of the known differences between BPD and MPD:
 * Advanced playback features like cross-fade, ReplayGain and MixRamp are not
   supported due to BPD's simple audio player backend.
 * Advanced query syntax is not currently supported.
-* Not all tags (fields) are currently exposed to BPD. Clients also can't use
-  the ``tagtypes`` mask to hide fields.
+* Clients can't use the ``tagtypes`` mask to hide fields.
 * BPD's ``random`` mode is not deterministic and doesn't support priorities.
 * Mounts and streams are not supported. BPD can only play files from disk.
 * Stickers are not supported (although this is basically a flexattr in beets