CC-1469:

Crossfading support (non-equal power)

-initial commit

python_apps/pypo/pypoliqqueue.py

@@ -0,0 +1,104 @@
+from threading import Thread
+from collections import deque
+from datetime import datetime
+
+import traceback
+import sys
+
+from Queue import Empty
+
+import signal
+def keyboardInterruptHandler(signum, frame):
+    logger = logging.getLogger()
+    logger.info('\nKeyboard Interrupt\n')
+    sys.exit(0)
+signal.signal(signal.SIGINT, keyboardInterruptHandler)
+
+class PypoLiqQueue(Thread):
+    def __init__(self, q, telnet_lock, logger, liq_queue_tracker, \
+            telnet_liquidsoap):
+        Thread.__init__(self)
+        self.queue = q
+        self.telnet_lock = telnet_lock
+        self.logger = logger
+        self.liq_queue_tracker = liq_queue_tracker
+        self.telnet_liquidsoap = telnet_liquidsoap
+
+    def main(self):
+        time_until_next_play = None
+        schedule_deque = deque()
+        media_schedule = None
+
+        while True:
+            try:
+                if time_until_next_play is None:
+                    media_schedule = self.queue.get(block=True)
+                else:
+                    media_schedule = self.queue.get(block=True, timeout=time_until_next_play)
+            except Empty, e:
+                #Time to push a scheduled item.
+                media_item = schedule_deque.popleft()
+                self.telnet_to_liquidsoap(media_item)
+                if len(schedule_deque):
+                    time_until_next_play = \
+                            self.date_interval_to_seconds(
+                                    schedule_deque[0]['start'] - datetime.utcnow())
+                else:
+                    time_until_next_play = None
+            else:
+                #new schedule received. Replace old one with this.
+                schedule_deque.clear()
+
+                keys = sorted(media_schedule.keys())
+                for i in keys:
+                    schedule_deque.append(media_schedule[i])
+
+                time_until_next_play = self.date_interval_to_seconds(\
+                        keys[0] - datetime.utcnow())
+
+    def is_media_item_finished(self, media_item):
+        return datetime.utcnow() > media_item['end']
+
+    def telnet_to_liquidsoap(self, media_item):
+        """
+        telnets to liquidsoap and pushes the media_item to its queue. Push the
+        show name of every media_item as well, just to keep Liquidsoap up-to-date
+        about which show is playing.
+        """
+        
+        available_queue = None
+        for i in self.liq_queue_tracker:
+            mi = self.liq_queue_tracker[i]
+            if mi == None or self.is_media_item_finished(mi):
+                #queue "i" is available. Push to this queue
+                available_queue = i
+
+        if available_queue == None:
+            raise NoQueueAvailableException()
+
+        try:
+            self.telnet_liquidsoap.queue_push(available_queue, media_item)
+            self.liq_queue_tracker[available_queue] = media_item
+        except Exception as e:
+            self.logger.error(e)
+            raise
+
+    def date_interval_to_seconds(self, interval):
+        """
+        Convert timedelta object into int representing the number of seconds. If
+        number of seconds is less than 0, then return 0.
+        """
+        seconds = (interval.microseconds + \
+                   (interval.seconds + interval.days * 24 * 3600) * 10 ** 6) / float(10 ** 6)
+        if seconds < 0: seconds = 0
+
+        return seconds
+
+
+    def run(self):
+        try: self.main()
+        except Exception, e:
+            self.logger.error('PypoLiqQueue Exception: %s', traceback.format_exc())
+
+class NoQueueAvailableException(Exception):
+    pass