def get_time(self):
self._last_hb_ts = time.time() * MICROSECONDS
content = utils.unserialize_response(request.get_data())
command_epoch = content['command_epoch']
if "term" in content and int(content["term"]) > self._master_term:
self._master_term = int(content["term"])
if "ip" in content and (self._master_ip == None
or self._master_ip != content["ip"]):
self._master_ip = content["ip"]
curr_time = time.time() * MICROSECONDS
curr_micros = int(round(curr_time))
if self._in_recovery:
failover_resp = utils.format_rpc_response(False, HB, {}, \
msg='Replica in recovery mode', \
command_epoch=command_epoch)
return utils.serialize_response(failover_resp)
with self._pygame_lock:
replica_playing = pygame.mixer.music.get_busy()
# Song has finished playing
if not replica_playing:
self._current_song = None
resp = utils.format_rpc_response(True, HB, \
{'time' : curr_micros, \
'replica_playing': replica_playing},
command_epoch = command_epoch)
return utils.serialize_response(resp)
def pause(self):
self._last_hb_ts = time.time() * MICROSECONDS
content = utils.unserialize_response(request.get_data())
command_epoch = content['command_epoch']
master_stop_micros = content['stop_time']
if self._in_recovery:
failover_resp = utils.format_rpc_response(False, PAUSE, {}, \
msg='Replica in recovery mode', \
command_epoch=command_epoch)
return utils.serialize_response(failover_resp)
# Wait till appointed stop time, allowed to be less precise than play
# (if vs while loop)
curr_replica_micros = int(round(time.time() * MICROSECONDS))
if (curr_replica_micros < master_stop_micros):
time.sleep((master_stop_micros - curr_replica_micros) /
float(MICROSECONDS))
with self._pygame_lock:
pygame.mixer.music.pause()
# return offset from start of song
replica_offset = int(round(pygame.mixer.music.get_pos()))
replica_micros = int(round(time.time() * MICROSECONDS))
resp = \
utils.format_rpc_response(True, PAUSE, \
{'time': replica_micros, \
'offset': replica_offset}, \
command_epoch=command_epoch)
return utils.serialize_response(resp)
def recover_replica(self):
data = utils.unserialize_response(request.get_data())
replica_song_hashes = data['song_hashes']
with open(PLAYLIST_STATE_FILE, 'r') as f:
data = utils.unserialize_response(f.read())
print data
master_queue = data['playlist']
current_song = data['current_song']
missing_songs = {}
print master_queue
for song_hash in master_queue:
print 'song_hash ' + str(song_hash)
music_path = utils.get_music_path(song_hash)
if (os.path.exists(music_path)) and (
replica_song_hashes.count(song_hash + EXT) == 0):
with open(music_path, 'r') as f:
song_bytes = f.read()
missing_songs[song_hash + EXT] = song_bytes
if current_song != None:
music_path = utils.get_music_path(current_song)
if (os.path.exists(current_song + EXT)) and (
replica_song_hashes.count(current_song + EXT) == 0):
with open(music_path, 'r') as f:
song_bytes = f.read()
missing_songs[current_song + EXT] = song_bytes
resp = utils.format_rpc_response(
True, RECOVER, {
'songs': missing_songs,
'master_queue': master_queue,
'current_song': current_song
})
return utils.serialize_response(resp)
def recover_replica(self):
data = utils.unserialize_response(request.get_data())
replica_song_hashes = data['song_hashes']
with open(PLAYLIST_STATE_FILE, 'r') as f:
data = utils.unserialize_response(f.read())
print data
master_queue = data['playlist']
current_song = data['current_song']
missing_songs = {}
print master_queue
for song_hash in master_queue:
print 'song_hash ' + str(song_hash)
music_path = utils.get_music_path(song_hash)
if (os.path.exists(music_path)) and (replica_song_hashes.count(song_hash + EXT) == 0):
with open(music_path, 'r') as f:
song_bytes = f.read()
missing_songs[song_hash + EXT] = song_bytes
if current_song != None:
music_path = utils.get_music_path(current_song)
if (os.path.exists(current_song + EXT)) and (replica_song_hashes.count(current_song + EXT) == 0):
with open(music_path, 'r') as f:
song_bytes = f.read()
missing_songs[current_song + EXT] = song_bytes
resp = utils.format_rpc_response(True, RECOVER, {'songs': missing_songs, 'master_queue': master_queue, 'current_song': current_song})
return utils.serialize_response(resp)
def check_song(self, song_hash):
self._last_hb_ts = time.time() * MICROSECONDS
content = utils.unserialize_response(request.get_data())
command_epoch = content['command_epoch']
if self._in_recovery:
failover_resp = utils.format_rpc_response(False, CHECK, {}, \
msg='Replica in recovery mode', \
command_epoch=command_epoch)
return utils.serialize_response(failover_resp)
if song_hash in self._song_hashes:
resp = utils.format_rpc_response(True, CHECK, \
{'has_song': True, 'ip': self._ip}, \
command_epoch = command_epoch)
else:
resp = utils.format_rpc_response(True, CHECK, {'ip': self._ip}, \
command_epoch = command_epoch)
return utils.serialize_response(resp)
def enqueue_song(self, song_hash):
self._last_hb_ts = time.time() * MICROSECONDS
content = utils.unserialize_response(request.get_data())
command_epoch = content['command_epoch']
master_post_hash = content['hashed_post_playlist']
master_current_song = content['current_song']
failover_resp = utils.format_rpc_response(False, ENQUEUE, {}, \
msg='Replica in recovery mode', \
command_epoch=command_epoch)
if self._in_recovery:
return utils.serialize_response(failover_resp)
print "In Enqueue"
print "Enqueue: " + str(self._current_song)
replica_pre_hash = utils.hash_string(pickle.dumps(
self._playlist_queue))
if replica_pre_hash == master_post_hash and self._current_song == master_current_song:
print "Already Performed Operation in Enqueue"
repeat_resp = utils.format_rpc_response(False, ENQUEUE, {}, \
msg='Already performed operation', \
command_epoch=command_epoch)
return utils.serialize_response(repeat_resp)
# Do enqueue, check for failover mode
song_not_exist = not os.path.exists(utils.get_music_path(song_hash))
self._playlist_queue.append(song_hash)
replica_post_hash = utils.hash_string(
pickle.dumps(self._playlist_queue))
inconsistent_queue = master_post_hash != replica_post_hash or \
master_current_song != self._current_song
print "queue hashes match: " + str(
master_post_hash == replica_post_hash)
print "current song matches: " + str(
master_current_song) + " == " + str(self._current_song)
replica_failover = song_not_exist or inconsistent_queue
if replica_failover:
self._in_recovery = True
return utils.serialize_response(failover_resp)
master_time = content['time']
self._master_timestamp = master_time
resp = utils.format_rpc_response(True, ENQUEUE, {'enqueued': True}, \
command_epoch=command_epoch)
print str(resp)
return utils.serialize_response(resp)
def dequeue_song(self):
self._last_hb_ts = time.time() * MICROSECONDS
content = utils.unserialize_response(request.get_data())
command_epoch = content['command_epoch']
master_post_hash = content['hashed_post_playlist']
master_current_song = content['current_song']
failover_resp = utils.format_rpc_response(False, DEQUEUE, {}, \
msg='Replica in recovery mode', \
command_epoch=command_epoch)
if self._in_recovery:
return utils.serialize_response(failover_resp)
print "In Dequeue"
replica_pre_hash = utils.hash_string(pickle.dumps(
self._playlist_queue))
if replica_pre_hash == master_post_hash and self._current_song == master_current_song and self._current_song != None:
repeat_resp = utils.format_rpc_response(False, DEQUEUE, {}, \
msg='Already performed operation', \
command_epoch=command_epoch)
return utils.serialize_response(repeat_resp)
# Check for length 0 queue
if len(self._playlist_queue) == 0:
self._current_song = None
else:
self._current_song = self._playlist_queue.popleft()
replica_post_hash = utils.hash_string(
pickle.dumps(self._playlist_queue))
if (replica_post_hash != master_post_hash
or self._current_song != master_current_song):
self._in_recovery = True
return utils.serialize_response(failover_resp)
master_time = content['time']
self._master_timestamp = master_time
resp = utils.format_rpc_response(True, DEQUEUE, {}, \
msg='Successfully dequeued', \
command_epoch=command_epoch)
print "end of dequeue: current song for replica: " + str(
self._current_song)
return utils.serialize_response(resp)
def load_song(self, song_hash):
content = utils.unserialize_response(request.get_data())
command_epoch = content['command_epoch']
song_bytes = content['song_bytes']
if self._in_recovery:
failover_resp = utils.format_rpc_response(False, LOAD, {}, \
msg='Replica in recovery mode', \
command_epoch=command_epoch)
self._last_hb_ts = time.time() * MICROSECONDS
return utils.serialize_response(failover_resp)
try:
with open(utils.get_music_path(song_hash), 'w') as f:
f.write(song_bytes)
except Exception:
resp = utils.format_rpc_response(False, LOAD, {}, \
msg='Error occured in writing to replica', \
command_epoch=command_epoch)
else:
self._song_hashes.add(song_hash)
resp = utils.format_rpc_response(True, LOAD, \
{'has_song': True, 'ip':self._ip}, \
command_epoch=command_epoch)
self._last_hb_ts = time.time() * MICROSECONDS
return utils.serialize_response(resp)
def play(self):
self._last_hb_ts = time.time() * MICROSECONDS
# Parse payload
content = utils.unserialize_response(request.get_data())
command_epoch = content['command_epoch']
start_time_microsec = content['start_time']
# Not sure when it would be -1 but double check
assert (start_time_microsec >= 0)
master_offset = 0
if 'offset' in content:
master_offset = int(content['offset'])
# May be None, need to call .stop() then
song_hash = content['song_hash']
failover_mode_resp = utils.format_rpc_response(\
False, PLAY, {}, \
msg='Replica in recovery mode', \
command_epoch=command_epoch)
# Case 1: Failover Mode already
# Short circuit crucial to not starve failover_service process on
# pygame_mixer object
# Case 2: Song hash doesn't exist
if self._in_recovery or (song_hash != None and not \
os.path.exists(utils.get_music_path(song_hash))):
self._in_recovery = True
return utils.serialize_response(failover_mode_resp)
# Could be in recovery mode at this point, wait for it to finish
# before moving on (True)
with self._pygame_lock:
replica_offset = int(round(pygame.mixer.music.get_pos()))
offset_diff = master_offset - replica_offset
# Ideally if pygame.mixer.music.play(offset) works then these would not be
# errors but alas such is life and we must go into recovery
if master_offset > 0:
# Case 3: Unpause command, but songs do not match
# Case 4: Unpause command, but master's offset is way in future
# This should not happen since master determines
# offset as max of replica offsets
if self._current_song != song_hash or \
abs(offset_diff) > MAX_OFFSET_DIF:
self._in_recovery = True
return utils.serialize_response(failover_mode_resp)
elif song_hash != None:
print "Loaded song"
pygame.mixer.music.stop()
pygame.mixer.music.load(utils.get_music_path(song_hash))
# Adjust start_time_microsec to account for offset difference
if master_offset > 0:
start_time_microsec = \
start_time_microsec - (offset_diff*MILLISECONDS)
# wait until start time, then play
curr_replica_microsec = int(round(time.time() * MICROSECONDS))
print song_hash
print master_offset
while (curr_replica_microsec + ALLOWED_REPLICA_BUFFER <
start_time_microsec):
curr_replica_microsec = int(round(time.time() * MICROSECONDS))
print "Song hash: " + str(song_hash)
if song_hash == None:
pygame.mixer.music.stop()
elif master_offset == 0:
pygame.mixer.music.play(1)
else:
pygame.mixer.music.unpause()
time.sleep(2) # necessary to allow mp3 thread to start?
self._current_song = song_hash
curr_replica_microsec = int(round(time.time() * MICROSECONDS))
resp = utils.format_rpc_response(True, PLAY, \
{'time': curr_replica_microsec }, \
command_epoch='command_epoch')
print "Play: " + str(self._current_song)
return utils.serialize_response(resp)
def postload_song(self):
self._loading_song = False
resp = utils.format_rpc_response(True, POSTLOAD, {})
return utils.serialize_response(resp)
def preload_song(self):
self._loading_song = True
resp = utils.format_rpc_response(True, PRELOAD, {})
return utils.serialize_response(resp)
