Refactored webtorrent plugin and synchronization with the player

The WebTorrent plugin now uses the `download -o <download_dir> -p <port>` options.
Improved interaction both with the webtorrent executable and the player
executable, and triggering the right events upon state changes, as well
as free support for torrent streaming through the webtorrent executable.

platypush/message/event/torrent.py

@@ -10,6 +10,15 @@ class TorrentEvent(Event):
         super().__init__(*args, **kwargs)
 
 
+class TorrentDownloadingMetadataEvent(TorrentEvent):
+    """
+    Event triggered upon torrent metadata download start
+    """
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+
 class TorrentDownloadStartEvent(TorrentEvent):
     """
     Event triggered upon torrent download start

platypush/plugins/media/__init__.py

@@ -27,6 +27,10 @@ class MediaPlugin(Plugin):
         * **youtube-dl** installed on your system (see your distro instructions), optional for YouTube support
     """
 
+    # A media plugin can either be local or remote (e.g. control media on
+    # another device)
+    _is_local = True
+
     _NOT_IMPLEMENTED_ERR = NotImplementedError(
         'This method must be implemented in a derived class')
 
@@ -360,5 +364,8 @@ class MediaPlugin(Plugin):
 
         return proc.stdout.read().decode("utf-8", "strict")[:-1]
 
+    def is_local(self):
+        return self._is_local
+
 
 # vim:sw=4:ts=4:et:

platypush/plugins/media/mplayer.py

@@ -72,8 +72,9 @@ class MediaMplayerPlugin(MediaPlugin):
         self.args = args or []
         self._init_mplayer_bin()
         self._build_actions()
-        self._mplayer = None
+        self._player = None
         self._mplayer_timeout = mplayer_timeout
+        self._mplayer_stopped_event = threading.Event()
         self._is_playing_torrent = False
 
 
@@ -98,9 +99,9 @@ class MediaMplayerPlugin(MediaPlugin):
             self.mplayer_bin = mplayer_bin
 
     def _init_mplayer(self, mplayer_args=None):
-        if self._mplayer:
+        if self._player:
             try:
-                self._mplayer.quit()
+                self._player.quit()
             except:
                 self.logger.debug('Failed to quit mplayer before _exec: {}'.
                                   format(str))
@@ -119,7 +120,7 @@ class MediaMplayerPlugin(MediaPlugin):
         if self._env:
             popen_args['env'] = self._env
 
-        self._mplayer = subprocess.Popen(args, **popen_args)
+        self._player = subprocess.Popen(args, **popen_args)
         threading.Thread(target=self._process_monitor()).start()
 
     def _build_actions(self):
@@ -155,7 +156,7 @@ class MediaMplayerPlugin(MediaPlugin):
         if cmd_name == 'loadfile' or cmd_name == 'loadlist':
             self._init_mplayer(mplayer_args)
         else:
-            if not self._mplayer:
+            if not self._player:
                 self.logger.warning('MPlayer is not running')
 
         cmd = '{}{}{}{}\n'.format(
@@ -163,8 +164,8 @@ class MediaMplayerPlugin(MediaPlugin):
             cmd_name, ' ' if args else '',
             ' '.join(repr(a) for a in args)).encode()
 
-        self._mplayer.stdin.write(cmd)
+        self._player.stdin.write(cmd)
-        self._mplayer.stdin.flush()
+        self._player.stdin.flush()
         bus = get_bus()
 
         if cmd_name == 'loadfile' or cmd_name == 'loadlist':
@@ -173,23 +174,23 @@ class MediaMplayerPlugin(MediaPlugin):
             bus.post(MediaPauseEvent())
         elif cmd_name == 'quit' or cmd_name == 'stop':
             if cmd_name == 'quit':
-                self._mplayer.terminate()
+                self._player.terminate()
-                self._mplayer.wait()
+                self._player.wait()
-                try: self._mplayer.kill()
+                try: self._player.kill()
                 except: pass
-                self._mplayer = None
+                self._player = None
 
         if not wait_for_response:
             return
 
         poll = select.poll()
-        poll.register(self._mplayer.stdout, select.POLLIN)
+        poll.register(self._player.stdout, select.POLLIN)
         last_read_time = time.time()
 
         while time.time() - last_read_time < self._mplayer_timeout:
             result = poll.poll(0)
             if result:
-                line = self._mplayer.stdout.readline().decode()
+                line = self._player.stdout.readline().decode()
                 last_read_time = time.time()
 
                 if line.startswith('ANS_'):
@@ -222,15 +223,17 @@ class MediaMplayerPlugin(MediaPlugin):
 
     def _process_monitor(self):
         def _thread():
-            if not self._mplayer:
+            if not self._player:
                 return
 
-            self._mplayer.wait()
+            self._mplayer_stopped_event.clear()
+            self._player.wait()
             try: self.quit()
             except: pass
 
             get_bus().post(MediaStopEvent())
-            self._mplayer = None
+            self._mplayer_stopped_event.set()
+            self._player = None
 
         return _thread
 

platypush/plugins/media/omxplayer.py

@@ -1,3 +1,4 @@
+import enum
 import os
 import re
 import subprocess
@@ -13,6 +14,12 @@ from platypush.message.event.video import VideoPlayEvent, VideoPauseEvent, \
 from platypush.plugins import action
 
 
+class PlayerEvent(enum.Enum):
+    STOP = 'stop'
+    PLAY = 'play'
+    PAUSE = 'pause'
+
+
 class MediaOmxplayerPlugin(MediaPlugin):
     """
     Plugin to control video and media playback using OMXPlayer.
@@ -36,6 +43,7 @@ class MediaOmxplayerPlugin(MediaPlugin):
 
         self.args = args
         self._player = None
+        self._handlers = { e.value: [] for e in PlayerEvent }
 
     @action
     def play(self, resource):
@@ -278,19 +286,36 @@ class MediaOmxplayerPlugin(MediaPlugin):
 
         redis.send_message(msg)
 
+    def add_handler(self, event_type, callback):
+        if event_type not in self._handlers.keys():
+            raise AttributeError('{} is not a valid PlayerEvent type'.
+                                 format(event_type))
+
+        self._handlers[event_type].append(callback)
+
     def on_play(self):
         def _f(player):
-            self.send_message(VideoPlayEvent(video=self._player.get_source()))
+            video = self._player.get_source()
+            self.send_message(VideoPlayEvent(video=video))
+            for callback in self._handlers[PlayerEvent.PLAY.value]:
+                callback(video)
+
         return _f
 
     def on_pause(self):
         def _f(player):
-            self.send_message(VideoPauseEvent(video=self._player.get_source()))
+            video = self._player.get_source()
+            self.send_message(VideoPauseEvent(video=video))
+            for callback in self._handlers[PlayerEvent.PAUSE.value]:
+                callback(video)
+
         return _f
 
     def on_stop(self):
         def _f(player):
             self.send_message(VideoStopEvent())
+            for callback in self._handlers[PlayerEvent.STOP.value]:
+                callback()
         return _f
 
 

platypush/plugins/media/webtorrent.py

@@ -1,8 +1,9 @@
 import datetime
+import enum
 import os
+import re
 import select
 import subprocess
-import tempfile
 import threading
 import time
 
@@ -11,12 +12,20 @@ from platypush.context import get_bus, get_plugin
 from platypush.message.response import Response
 from platypush.plugins.media import PlayerState, MediaPlugin
 from platypush.message.event.torrent import TorrentDownloadStartEvent, \
-    TorrentDownloadCompletedEvent
+    TorrentDownloadCompletedEvent, TorrentDownloadProgressEvent, \
+    TorrentDownloadingMetadataEvent
 
 from platypush.plugins import action
-from platypush.utils import find_bins_in_path
+from platypush.utils import find_bins_in_path, find_files_by_ext, \
+    is_process_alive
 
 
+class TorrentState(enum.Enum):
+    IDLE = 1
+    DOWNLOADING_METADATA = 2
+    DOWNLOADING = 3
+    DOWNLOADED = 4
+
 class MediaWebtorrentPlugin(MediaPlugin):
     """
     Plugin to download and stream videos using webtorrent
@@ -38,7 +47,8 @@ class MediaWebtorrentPlugin(MediaPlugin):
     # Download at least 10 MBs before starting streaming
     _download_size_before_streaming = 10 * 2**20
 
-    def __init__(self, webtorrent_bin=None, *args, **kwargs):
+    def __init__(self, webtorrent_bin=None, webtorrent_port=None, *args,
+                 **kwargs):
         """
         media.webtorrent will use the default media player plugin you have
         configured (e.g. mplayer, omxplayer) to stream the torrent.
@@ -46,10 +56,15 @@ class MediaWebtorrentPlugin(MediaPlugin):
         :param webtorrent_bin: Path to your webtorrent executable. If not set,
             then Platypush will search for the right executable in your PATH
         :type webtorrent_bin: str
+
+        :param webtorrent_port: Port where the webtorrent will be running
+            streaming server will be running (default: 8000)
+        :type webtorrent_port: int
         """
 
         super().__init__(*args, **kwargs)
 
+        self.webtorrent_port = webtorrent_port
         self._init_webtorrent_bin(webtorrent_bin=webtorrent_bin)
         self._init_media_player()
 
@@ -97,38 +112,142 @@ class MediaWebtorrentPlugin(MediaPlugin):
                                     self._supported_media_plugins))
 
 
-    def _process_monitor(self, resource, output_file):
+    def _read_process_line(self):
+        line = self._webtorrent_process.stdout.readline().decode().strip()
+        # Strip output of the colors
+        return re.sub('\x1b\[((\d+m)|(.{1,2}))', '', line).strip()
+
+
+    def _process_monitor(self, resource, download_dir):
         def _thread():
             if not self._webtorrent_process:
                 return
 
+            ######
+            state = TorrentState.IDLE
             bus = get_bus()
-            bus.post(TorrentDownloadStartEvent(resource=resource))
+            webtorrent_url = None
+            media_file = None
 
+            poll = select.poll()
+            poll.register(self._webtorrent_process.stdout, select.POLLIN)
+
+            # First wait for the metadata to be ready and the streaming started
             while True:
+                result = poll.poll(0)
+                if not result:
+                    continue
+
+                if not self._is_process_alive():
+                    break
+
+                line = self._read_process_line()
+
+                if 'fetching torrent metadata from' in line.lower() \
+                        and state == TorrentState.IDLE:
+                    # IDLE -> DOWNLOADING_METADATA
+                    state = TorrentState.DOWNLOADING_METADATA
+                    bus.post(TorrentDownloadingMetadataEvent(resource=resource))
+                elif 'downloading: ' in line.lower() \
+                        and media_file is None:
+                    # Find video files in torrent directory
+                    output_dir = os.path.join(
+                        download_dir, re.search(
+                            'downloading: (.+?)$', line, flags=re.IGNORECASE
+                        ).group(1))
+
+                    media_files = sorted(find_files_by_ext(
+                        output_dir, *self._media_plugin.video_extensions))
+
+                    if not media_files:
+                        raise RuntimeError('No video files found in {}'.
+                                           format(output_dir))
+
+                    media_file = os.path.join(output_dir, media_files[0])
+                elif 'server running at: ' in line.lower() \
+                        and webtorrent_url is None:
+                    # Streaming started
+                    webtorrent_url = re.search('server running at: (.+?)$',
+                                               line, flags=re.IGNORECASE).group(1)
+                    self.logger.info('Torrent stream started on {}'.format(
+                        webtorrent_url))
+
+                if state.value <= TorrentState.DOWNLOADING_METADATA.value \
+                        and media_file and webtorrent_url:
+                    # DOWNLOADING_METADATA -> DOWNLOADING
+                    state = TorrentState.DOWNLOADING
+                    bus.post(TorrentDownloadStartEvent(
+                        resource=resource, media_file=media_file,
+                        stream_url=webtorrent_url))
+                    break
+
+
+            if not media_file or not webtorrent_url:
+                raise RuntimeError('The webtorrent process did not ' +
+                                    'provide the required data')
+
+            # Then wait until we have enough chunks to start the player
+            while True:
+                result = poll.poll(0)
+                if not result:
+                    continue
+
+                if not self._is_process_alive():
+                    break
+
                 try:
-                    if os.path.getsize(output_file) > \
+                    if os.path.getsize(media_file) > \
                             self._download_size_before_streaming:
                         break
                 except FileNotFoundError:
-                    pass
+                    continue
 
-            self._media_plugin.play(output_file)
+            self.logger.info(
-            self._webtorrent_process.wait()
+                'Starting playback of {} to {} through {}'.format(
+                    media_file, self._media_plugin.__class__.__name__,
+                    webtorrent_url))
+
+            media = media_file if self._media_plugin.is_local() \
+                else webtorrent_url
+
+            self._media_plugin.play(media)
+            self.logger.info('Waiting for player to terminate')
+            self._wait_for_player()
+            self.logger.info('Torrent player terminated')
             bus.post(TorrentDownloadCompletedEvent(resource=resource))
-            self._webtorrent_process = None
+
+            try: self.quit()
+            except: pass
+            self.logger.info('WebTorrent process terminated')
 
         return _thread
 
+    def _wait_for_player(self):
+        media_cls = self._media_plugin.__class__.__name__
+        stop_evt = None
 
-    def _get_torrent_download_path(self):
+        if media_cls == 'MediaMplayerPlugin':
-        if self._media_plugin.download_dir:
+            stop_evt = self._media_plugin._mplayer_stopped_event
-            # TODO set proper file name based on the torrent metadata
+        elif media_cls == 'MediaOmxplayerPlugin':
-            return os.path.join(self._media_plugin.download_dir,
+            stop_evt = threading.Event()
-                                'torrent_media_' + datetime.datetime.
+            def stop_callback():
-                                today().strftime('%Y-%m-%d_%H-%M-%S-%f'))
+                stop_evt.set()
+            self._media_plugin.add_handler('stop', stop_callback)
+
+        if stop_evt:
+            stop_evt.wait()
         else:
-            return tempfile.NamedTemporaryFile(delete=False).name
+            # Fallback: wait for the webtorrent process to terminate
+            self._webtorrent_process.wait()
+
+
+    def _get_torrent_download_dir(self):
+        if self._media_plugin.download_dir:
+            return self._media_plugin.download_dir
+        else:
+            d = os.path.join(os.environ['HOME'], 'Downloads')
+            os.makedirs(d, exist_ok=True)
+            return d
 
 
     @action
@@ -148,16 +267,18 @@ class MediaWebtorrentPlugin(MediaPlugin):
                 self.logger.debug('Failed to quit the previous instance: {}'.
                                   format(str))
 
-        output_file = self._get_torrent_download_path()
+        download_dir = self._get_torrent_download_dir()
-        webtorrent_args = [self.webtorrent_bin, '--stdout', resource]
+        webtorrent_args = [self.webtorrent_bin, 'download', '-o', download_dir]
 
-        with open(output_file, 'w') as f:
+        if self.webtorrent_port:
-            self._webtorrent_process = subprocess.Popen(webtorrent_args,
+            webtorrent_args += ['-p', self.webtorrent_port]
-                                                        stdout=f)
 
-            threading.Thread(target=self._process_monitor(
+        webtorrent_args += [resource]
-                resource=resource, output_file=output_file)).start()
+        self._webtorrent_process = subprocess.Popen(webtorrent_args,
+                                                    stdout=subprocess.PIPE)
 
+        threading.Thread(target=self._process_monitor(
+            resource=resource, download_dir=download_dir)).start()
         return { 'resource': resource }
 
 
@@ -169,8 +290,7 @@ class MediaWebtorrentPlugin(MediaPlugin):
     @action
     def quit(self):
         """ Quit the player """
-        if self._webtorrent_process and self._is_process_alive(
+        if self._is_process_alive():
-                self._webtorrent_process.pid):
             self._webtorrent_process.terminate()
             self._webtorrent_process.wait()
             try: self._webtorrent_process.kill()
@@ -186,15 +306,8 @@ class MediaWebtorrentPlugin(MediaPlugin):
         return self.play(resource)
 
     def _is_process_alive(self):
-        if not self._webtorrent_process:
+        return is_process_alive(self._webtorrent_process.pid) \
-            return False
+            if self._webtorrent_process else False
-
-        try:
-            os.kill(self._webtorrent_process.pid, 0)
-            return True
-        except OSError:
-            self._webtorrent_process = None
-            return False
 
     @action
     def status(self):

platypush/utils/__init__.py

@@ -180,4 +180,34 @@ def find_bins_in_path(bin_name):
                  os.access(os.path.join(p, bin_name), os.X_OK))]
 
 
+def find_files_by_ext(directory, *exts):
+    """
+    Finds all the files in the given directory with the provided extensions
+    """
+
+    if not exts:
+        raise AttributeError('No extensions provided')
+
+    if not os.path.isdir(directory):
+        raise AttributeError('{} is not a valid directory'.format(directory))
+
+    min_len = len(min(exts, key=len))
+    max_len = len(max(exts, key=len))
+    result = []
+
+    for root, dirs, files in os.walk(directory):
+        for i in range(min_len, max_len+1):
+            result += [f for f in files if f[-i:] in exts]
+
+    return result
+
+
+def is_process_alive(pid):
+    try:
+        os.kill(pid, 0)
+        return True
+    except OSError:
+        return False
+
+
 # vim:sw=4:ts=4:et: