def backward():
url = get_url(BACKWARD)
try:
r = urllib2.urlopen(url)
print utils.unserialize_response(r.read())
except Exception:
print "Error in Backwarding Song"
def play():
url = get_url(PLAY)
try:
r = urllib2.urlopen(url)
print utils.unserialize_response(r.read())
except Exception:
print "Error in Playing Song"
def load(song_file):
song_path = MUSIC_DIR + song_file
m = hashlib.md5()
assert(os.path.exists(song_path))
with open(song_path, 'r') as f:
song_bytes = f.read()
song_hash = hashlib.sha224(song_bytes).hexdigest()
url = get_url(LOAD) + "/" + song_hash
try:
r = urllib2.urlopen(url)
except Exception:
print "Error in Checking Song"
else:
master_response = utils.unserialize_response(r.read())
has_file = master_response['success']
if not has_file:
try:
req = urllib2.Request(url)
except Exception:
print "Error in Uploading Song"
else:
d = {'song_bytes': song_bytes}
req.add_data(utils.serialize_response(d))
r = urllib2.urlopen(req)
master_response = utils.unserialize_response(r.read())
if not master_response['success']:
print master_response['msg']
print master_response['client_req_id']
return 'load'
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 load_song(song_path):
m = hashlib.md5()
assert (os.path.exists(song_path))
with open(song_path, 'r') as f:
song_bytes = f.read()
song_hash = hashlib.sha224(song_bytes).hexdigest()
url = get_url(LOAD) + "/" + song_hash
try:
r = urllib2.urlopen(url)
except Exception:
print "Error in Checking Song"
else:
master_response = utils.unserialize_response(r.read())
has_file = master_response['success']
if not has_file:
try:
req = urllib2.Request(url)
except Exception:
print "Error in Uploading Song"
else:
d = {'song_bytes': song_bytes}
req.add_data(utils.serialize_response(d))
r = urllib2.urlopen(req)
master_response = utils.unserialize_response(r.read())
if not master_response['success']:
print master_response['msg']
print master_response['client_req_id']
def backward():
url = get_url(BACKWARD)
try:
r = urllib2.urlopen(url)
print utils.unserialize_response(r.read())
except Exception:
print "Error in Backwarding Song"
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 play():
url = get_url(PLAY)
try:
r = urllib2.urlopen(url)
print utils.unserialize_response(r.read())
except Exception:
print "Error in Playing Song"
def pause():
url = get_url(PAUSE)
print url
try:
r = urllib2.urlopen(url)
print utils.unserialize_response(r.read())
except Exception:
print "Error in Pausing Song"
def pause():
url = get_url(PAUSE)
print url
try:
r = urllib2.urlopen(url)
print utils.unserialize_response(r.read())
except Exception:
print "Error in Pausing Song"
def load_song(self, song_hash):
print "master client: load song"
self.inc_client_req_id()
command_info = {
'command': LOAD,
'master_ip': self._ip,
'params': {
'song_hash': song_hash
},
'client_req_id': self._client_req_id
}
if request.method == 'GET':
if os.path.exists(utils.get_music_path(song_hash)):
self._command_queue.put(command_info)
return self.wait_on_master_music_service(LOAD)
# song doesn't exist on master, get the song from the client
else:
return utils.serialize_response(
utils.format_client_response(
False,
LOAD, {},
msg='Master does not have requested song'))
elif request.method == 'POST':
data = utils.unserialize_response(request.get_data())
with open(utils.get_music_path(song_hash), 'w') as f:
f.write(data['song_bytes'])
self._command_queue.put(command_info)
return self.wait_on_master_music_service(LOAD)
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 pause():
url = get_url(PAUSE)
try:
r = urllib2.urlopen(url)
resp = utils.unserialize_response(r.read())
except Exception:
resp = {"success": False, "msg": "Error in Pausing Song"}
return resp
def backward():
url = get_url(BACKWARD)
try:
r = urllib2.urlopen(url)
resp = utils.unserialize_response(r.read())
except Exception:
resp = {"success": False, "msg": "Error in Backwarding Song"}
return resp
def pause():
url = get_url(PAUSE)
try:
r = urllib2.urlopen(url)
resp = utils.unserialize_response(r.read())
except Exception:
resp = {"success": False, "msg": "Error in Pausing Song"}
return resp
def backward():
url = get_url(BACKWARD)
try:
r = urllib2.urlopen(url)
resp = utils.unserialize_response(r.read())
except Exception:
resp = {"success": False, "msg": "Error in Backwarding Song"}
return resp
def forward():
global playlist
url = get_url(FORWARD)
try:
r = urllib2.urlopen(url)
resp = utils.unserialize_response(r.read())
if len(playlist) != 0:
playlist.pop(0)
except Exception:
resp = {"success": False, "msg": "Error in Forwarding Song"}
return resp
def forward():
global playlist
url = get_url(FORWARD)
try:
r = urllib2.urlopen(url)
resp = utils.unserialize_response(r.read())
if len(playlist) != 0:
playlist.pop(0)
except Exception:
resp = {"success": False, "msg": "Error in Forwarding Song"}
return 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 load_song(self, song_hash):
print "master client: load song"
self.inc_client_req_id()
command_info = {'command':LOAD, 'master_ip': self._ip, 'params':{'song_hash':song_hash}, 'client_req_id': self._client_req_id}
if request.method == 'GET':
if os.path.exists(utils.get_music_path(song_hash)):
self._command_queue.put(command_info)
return self.wait_on_master_music_service(LOAD)
# song doesn't exist on master, get the song from the client
else:
return utils.serialize_response(utils.format_client_response(False, LOAD, {}, msg='Master does not have requested song'))
elif request.method == 'POST':
data = utils.unserialize_response(request.get_data())
with open(utils.get_music_path(song_hash), 'w') as f:
f.write(data['song_bytes'])
self._command_queue.put(command_info)
return self.wait_on_master_music_service(LOAD)
def enqueue_song(song_path):
load_song(song_path)
assert (os.path.exists(song_path))
with open(song_path, 'r') as f:
song_bytes = f.read()
song_hash = utils.hash_string(song_bytes)
url = get_url(ENQUEUE) + "/" + song_hash
try:
r = urllib2.urlopen(url)
except Exception:
print "Error in Enqueue Song"
else:
master_response = utils.unserialize_response(r.read())
if master_response['success'] == True:
print song_path + ' has been enqueued'
else:
print song_path + ' cannot be enqueued'
print master_response['client_req_id']
def enqueue_song(song_path):
load_song(song_path)
assert(os.path.exists(song_path))
with open(song_path, 'r') as f:
song_bytes = f.read()
song_hash = utils.hash_string(song_bytes)
url = get_url(ENQUEUE) + "/" + song_hash
try:
r = urllib2.urlopen(url)
except Exception:
print "Error in Enqueue Song"
else:
master_response = utils.unserialize_response(r.read())
if master_response['success'] == True:
print song_path + ' has been enqueued'
else:
print song_path + ' cannot be enqueued'
print master_response['client_req_id']
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 enqueue(song_file):
global playlist
playlist.append(song_file)
return 'songthing'
song_path = MUSIC_DIR + song_file
load_song(song_path)
assert (os.path.exists(song_path))
with open(song_path, 'r') as f:
song_bytes = f.read()
song_hash = utils.hash_string(song_bytes)
url = get_url(ENQUEUE) + "/" + song_hash
try:
r = urllib2.urlopen(url)
except Exception:
print "Error in Enqueue Song"
else:
master_response = utils.unserialize_response(r.read())
if master_response['success'] == True:
print song_path + ' has been enqueued'
playlist.append(song_file)
else:
print song_path + ' cannot be enqueued'
print master_response['client_req_id']
return 'enqueue'
def enqueue(song_file):
global playlist
playlist.append(song_file)
return 'songthing'
song_path = MUSIC_DIR + song_file
load_song(song_path)
assert(os.path.exists(song_path))
with open(song_path, 'r') as f:
song_bytes = f.read()
song_hash = utils.hash_string(song_bytes)
url = get_url(ENQUEUE) + "/" + song_hash
try:
r = urllib2.urlopen(url)
except Exception:
print "Error in Enqueue Song"
else:
master_response = utils.unserialize_response(r.read())
if master_response['success'] == True:
print song_path + ' has been enqueued'
playlist.append(song_file)
else:
print song_path + ' cannot be enqueued'
print master_response['client_req_id']
return 'enqueue'
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 reconnected_replica(self):
print "RECONNECTING F*****G REPLICA"
data = utils.unserialize_response(request.get_data())
if data['msg'] == 'yo':
return utils.serialize_response({'msg': 'yo'})
def reconnected_replica(self):
print "RECONNECTING F*****G REPLICA"
data = utils.unserialize_response(request.get_data())
if data['msg'] == 'yo':
return utils.serialize_response({'msg': 'yo'})
def run(self):
self._data['master_ip'] = self._parent._master_ip
request_data = utils.serialize_response(self._data)
req = urllib2.Request(self._url, request_data)
start = int(round(time.time() * MICROSECONDS))
# TODO: deal with timeout error
response = urllib2.urlopen(req).read()
end = int(round(time.time() * MICROSECONDS))
try:
response_data = utils.unserialize_response(response)
except:
# votes should fail to unserialize
response_data = response
if "yes" in response_data:
self._parent.yes_votes[self._ip] = "yes"
return
# Short circuit out to prevent races, ignore timed out rpc calls
print str(response_data)
if 'command_epoch' in response_data and response_data['command_epoch'] != self._parent.command_epoch:
return
response_command = response_data['command']
response_success = response_data['success']
response_params = response_data['params']
assert(response_command == self._command)
if response_success:
# Response received from replica
self._parent.rpc_response_acks += 1
# Heartbeat time delay estimate
if response_command == HB:
# Replica_playing is True if playing or paused
# False if song stopped
replica_playing = int(response_params['replica_playing'])
response_time = int(response_params['time'])
self._parent.update_latency(self._ip, (end - start) / 2.0)
if not replica_playing:
self._parent.rpc_not_playing_acks += 1
else:
self._parent.rpc_playing_acks += 1
# estimate for other computers clock time: their time,
# plus return network latency, which we approximate with (end-start)/2
clock_estimate = response_time + (end - start) / 2
diff = clock_estimate - end
self._parent.update_clock_diff(self._ip, diff)
# Check the offsets in PAUSE
elif response_command == PAUSE:
response_offset = int(response_params['offset'])
if response_offset > -1:
self._parent.rpc_offsets.append(response_offset)
# Check if song has loaded/not loaded on replica
elif response_command == LOAD:
if 'has_song' in response_params:
self._parent.rpc_loaded_ips.put(response_params['ip'] + ':' + REPLICA_PORT)
elif response_command == CHECK:
if 'has_song' in response_params:
self._parent.rpc_loaded_ips.put(response_params['ip'] + ':' + REPLICA_PORT)
else:
self._parent.rpc_not_loaded_ips.put(response_params['ip'] + ':' + REPLICA_PORT)
else:
self._parent.rpc_not_playing_acks += 1
if DEBUG:
print "ip:" + self._ip + ":" + str(response_data)
def recover_state(self):
status_update_dict = { "reset_election" : True }
self._parent._state_queue.put(status_update_dict)
num_master_retries = 10 + random.randint(0, 10)
on_retry = 0
while True:
url = "http://" + self._parent._master_ip + ":" + REPLICA_FAIL_PORT + "/" + RECONNECT
print "connecting to master failover service: " + url
req = urllib2.Request(url, utils.serialize_response({'msg': 'yo'}))
try:
resp = urllib2.urlopen(req)
except Exception:
print "failed to reach master"
on_retry += 1
if on_retry > num_master_retries:
return True # attempt to get elected again
time.sleep(HEARTBEAT_PAUSE * 2)
else:
status_update_dict = { "new_master" : True }
self._parent._state_queue.put(status_update_dict)
response_data = utils.unserialize_response(resp.read())
assert (response_data['msg'] == 'yo')
break
url = "http://" + self._parent._master_ip + ":" + REPLICA_FAIL_PORT + "/" + RECOVER
data = {'song_hashes': []}
# if music directory exists, get the filenames, keep extension on filenames!!!
if os.path.exists(MUSIC_DIR):
for file_name in os.listdir(MUSIC_DIR):
if (len(file_name) >= len(EXT)) and (file_name.count(EXT) != 0):
data['song_hashes'].append(file_name)
else:
os.makedirs(MUSIC_DIR)
req = urllib2.Request(url, utils.serialize_response(data))
try:
resp = urllib2.urlopen(req)
except Exception:
return False
else:
# TODO: add timestamp from master
resp = resp.read()
# response should be a ton of music mp3 files serialized into a dictionary
response_data = utils.unserialize_response(resp)
songs = response_data['params']['songs']
master_queue = response_data['params']['master_queue']
current_song = response_data['params']['current_song']
self._parent._playlist_queue = master_queue
self._parent._current_song = current_song
#failed_file_names = []
# need to update self._song_hashes in replica music server
for file_name in songs:
try:
with open(file_name, 'w') as f:
f.write(songs[file_name])
except Exception:
print 'song failed to download in replica failover'
#failed_file_names.append(file_name)
else:
print 'successfully downloaded ' + file_name + ' in replica failover'
return True
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)
