docs

croaker/controller.py

@@ -9,6 +9,12 @@ logger = logging.getLogger('controller')
 
 
 class Controller(threading.Thread):
+    """
+    A background thread started by the CroakerServer instance that controls a
+    shoutcast source streamer. The primary purpose of this class is to allow
+    the command and control server to interrupt streaming operations to
+    skip to a new track or load a new playlist.
+    """
     def __init__(self, control_queue):
         self._streamer_queue = None
         self._control_queue = control_queue
@@ -24,6 +30,18 @@ class Controller(threading.Thread):
             self._streamer = AudioStreamer(self._streamer_queue, self.skip_event, self.stop_event)
         return self._streamer
 
+    def stop(self):
+        if self._streamer:
+            logging.debug("Sending STOP signal to streamer...")
+            self.stop_event.set()
+        self.playlist = None
+
+    def load(self, playlist_name: str):
+        self.playlist = load_playlist(playlist_name)
+        logger.debug(f"Switching to {self.playlist = }")
+        for track in self.playlist.tracks:
+            self._streamer_queue.put(str(track).encode())
+
     def run(self):
         logger.debug("Starting AudioStreamer...")
         self.streamer.start()
@@ -53,15 +71,3 @@ class Controller(threading.Thread):
 
     def handle_STOP(self):
         return self.stop()
-
-    def stop(self):
-        if self._streamer:
-            logging.debug("Sending STOP signal to streamer...")
-            self.stop_event.set()
-        self.playlist = None
-
-    def load(self, playlist_name: str):
-        self.playlist = load_playlist(playlist_name)
-        logger.debug(f"Switching to {self.playlist = }")
-        for track in self.playlist.tracks:
-            self._streamer_queue.put(str(track).encode())

croaker/server.py

@@ -14,7 +14,13 @@ logger = logging.getLogger('server')
 
 
 class RequestHandler(socketserver.StreamRequestHandler):
+    """
+    Instantiated by the TCPServer when a request is received. Implements the
+    command and control protocol and sends commands to the shoutcast controller
+    on behalf of the user.
+    """
     supported_commands = {
+        # command                  # help text
         "PLAY": "$PLAYLIST_NAME  - Switch to the specified playlist.",
         "FFWD": "                - Skip to the next track in the playlist.",
         "HELP": "                - Display command help.",
@@ -23,6 +29,16 @@ class RequestHandler(socketserver.StreamRequestHandler):
     }
 
     def handle(self):
+        """
+        Start a command and control session. Commands are read one line at a
+        time; the format is:
+
+        Byte     Definition
+        -------------------
+        0-3      Command
+        4        Ignored
+        5+       Arguments
+        """
         while True:
             self.data = self.rfile.readline().strip().decode()
             logger.debug(f"{self.data = }")
@@ -60,6 +76,9 @@ class RequestHandler(socketserver.StreamRequestHandler):
 
 
 class CroakerServer(socketserver.TCPServer):
+    """
+    A Daemonized TCP Server that also starts a Shoutcast source client.
+    """
     allow_reuse_address = True
 
     def __init__(self):
@@ -67,22 +86,33 @@ class CroakerServer(socketserver.TCPServer):
         self._queue = queue.Queue()
         self.controller = Controller(self._queue)
 
-    def _pidfile(self, terminate_if_running: bool = True):
-        return pidfile(path.root() / "croaker.pid", terminate_if_running=terminate_if_running)
+    def _pidfile(self):
+        return pidfile(path.root() / "croaker.pid")
 
     def tell_controller(self, msg):
+        """
+        Enqueue a message for the shoutcast controller.
+        """
         self._queue.put(msg)
 
     def bind_address(self):
         return (os.environ["HOST"], int(os.environ["PORT"]))
 
     def daemonize(self) -> None:
+        """
+        Daemonize the current process, start the shoutcast controller
+        background thread and then begin listening for connetions.
+        """
         logger.info(f"Daemonizing controller on {self.bind_address()}; pidfile and output in {path.root()}")
         super().__init__(self.bind_address(), RequestHandler)
 
         self._context.pidfile = self._pidfile()
-        self._context.stdout = open(path.root() / Path("croaker.out"), "wb")
+        self._context.stdout = open(path.root() / Path("croaker.out"), "wb", buffering=0)
         self._context.stderr = open(path.root() / Path("croaker.err"), "wb", buffering=0)
+
+        # when open() is called, all open file descriptors will be closed, as
+        # befits a good daemon. However this will also close the socket on
+        # which the TCPServer is listening! So let's keep that one open.
         self._context.files_preserve = [self.fileno()]
         self._context.open()
         try:

croaker/streamer.py

@@ -11,6 +11,10 @@ logger = logging.getLogger('streamer')
 
 
 class AudioStreamer(threading.Thread):
+    """
+    Receive filenames from the controller thread and stream the contents of
+    those files to the icecast server.
+    """
     def __init__(self, queue, skip_event, stop_event):
         super().__init__()
         self.queue = queue