def remove_subscription(ip, port, alarm_name):
# TODO: This is global and should probably not be
global subscriptions, alarm_queue
# Does the alarm exist
if alarm_name not in alarm_queue.names:
return Commands.create_command_string(('FN', alarm_name))
# Try to delete the subscription
client_obj = Client.Client(ip, port)
if alarm_name in alarm_queue.names:
if alarm_name in subscriptions:
if any(c for c in subscriptions[alarm_name] if c == client_obj):
try:
index = subscriptions[alarm_name].index(client_obj)
del subscriptions[alarm_name][index]
except ValueError:
# Not subscribed
return Commands.create_command_string(('FB', alarm_name))
# Not subscribed
else:
return Commands.create_command_string(('FB', alarm_name))
else:
# Not subscribed
return Commands.create_command_string(('FB', alarm_name))
# Tell the client they've been removed from the list
return Commands.create_command_string(('S', alarm_name))
def subscribe_to_alarms(alarms, settings):
# Did we subscribe to even one alarm?
success = False
# Connect to the server
t = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
t.settimeout(RESPONSE_TIMEOUT)
t.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
t.bind((settings['address'], settings['port']))
t.connect((settings['server_address'], settings['server_port']))
# Ask the server to subscribe us for each alarm
for alarm in alarms:
command_string = Commands.create_command_string(('B', alarm))
t.send(command_string)
Log.debug('Subscription request for alarm "%s" sent.' % alarm)
# Receive data
command_string = t.recv(BUFFER_SIZE)
# Print the command
Log.debug('Got response "%s"' % command_string)
# Parse the command
command = Commands.parse_command(command_string)
if command[0] == 'FB':
Log.debug('Already subscribed to alarm "%s".' % alarm)
success = True
elif command[0] == 'S':
Log.debug('Successfully subscribed to alarm "%s".' % alarm)
success = True
elif command[0] == 'FN':
Log.error('Server says alarm "%s" does not exist.' % alarm)
else:
Log.error('Unable to parse response from server.')
t.close()
return success
def add_subscription(ip, port, alarm_name):
# TODO: This is global and should probably not be
global subscriptions, alarm_queue
# Does the alarm exist
if alarm_name not in alarm_queue.names:
return Commands.create_command_string(('FN', alarm_name))
# Try to add the subscription
client_obj = Client.Client(ip, port)
if alarm_name in alarm_queue.names:
if alarm_name in subscriptions:
# Already subscribed
if any(c for c in subscriptions[alarm_name] if c == client_obj):
return Commands.create_command_string(('FB', alarm_name))
else:
subscriptions[alarm_name].append(client_obj)
else:
subscriptions[alarm_name] = [client_obj]
# Tell the client they've been added to the list
return Commands.create_command_string(('S', alarm_name))
def listen(settings):
# Create a socket and listen for packets
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.bind((settings['address'], settings['port']))
sock.listen(1)
Log.debug('Listening on port %i' % settings['port'])
# This is our main listening thread
while True:
# Accept incoming connection
connection, address = sock.accept()
server = address[0] + ':' + str(address[1])
Log.debug('Connection from %s' % server)
# Receive data
command_string = connection.recv(BUFFER_SIZE)
# Print the command
Log.debug('Received command %s from %s.' % (command_string, server))
# Parse the command
command = Commands.parse_command(command_string)
response = 'E general'
if command:
response = Commands.create_command_string(('F', command[1]))
# Handle the alarm
if command[0] == 'A':
Log.debug('Alarm %s triggered.', command[1])
result = dispatch_alarm(command[1])
# Success
if result:
response = Commands.create_command_string(('S', command[1]))
# Invalid command
else:
Log.error('Invalid command "%s" from server.', command[0])
# Invalid command
else:
Log.error('Invalid command from server.')
connection.send(response)
# Close the connection from the server
connection.close()
# Close the socket
sock.close()
# See how long we'll have to wait now
if len(alarm_queue) > 0:
alarm = alarm_queue.peek()
wait = alarm.wait_time()
Log.debug('Next alarm in %i seconds. Sleeping until then.' % wait)
# If two alarms occur at the same time, wait will be zero or negative.
# No point in sleeping if that's the case.
if wait > 0:
time.sleep(wait)
# Remove the alarm from the queue
alarm = alarm_queue.pop()
# If anybody cares about this alarm, alert them
if alarm.name in subscriptions:
clients = subscriptions[alarm.name]
Log.debug('Alerting %i clients about alarm "%s"' % (len(clients), alarm.name))
# Notify all subscribed clients
for client in clients:
# Spin off a thread to talk to the client
#t_handle = thread.start_new_thread(alert_client, (client, alarm))
c = Client.OutgoingClient(client.ip, client.port, handle_alarm_response)
c.send_command(Commands.create_command_string(('A', alarm.name)))
else:
Log.debug('No subscriptions to alarm "%s"' % alarm.name)
# Sleep for 1 second to prevent the alarm from firing again
time.sleep(1)
# Stick the alarm back in the queue if it repeats
if not alarm.once:
alarm_queue.enqueue(alarm)
