- #!/usr/bin/python3
- import logging
- import socket
- import json
- import sys
- from queue import Queue
- from gi.repository import GObject
- log = logging.getLogger('Connection')
- conn = None
- port = 9999
- command_queue = Queue()
- signal_handlers = {}
- def establish(host):
- global conn, port, log
- log.info('establishing Connection to %s', host)
- conn = socket.create_connection( (host, port) )
- log.debug('Connection successful \o/')
- def fetchServerConfig():
- global conn, log
- log.info('reading server-config')
- fd = conn.makefile('rw')
- fd.write("get_config\n")
- fd.flush()
- while True:
- line = fd.readline()
- words = line.split(' ')
- signal = words[0]
- args = words[1:]
- if signal != 'server_config':
- continue
- server_config_json = " ".join(args)
- server_config = json.loads(server_config_json)
- return server_config
- def enterNonblockingMode():
- global conn, log
- log.debug('entering nonblocking-mode')
- conn.setblocking(False)
- GObject.io_add_watch(conn, GObject.IO_IN, on_data, [''])
- GObject.idle_add(on_loop)
- def on_data(conn, _, leftovers, *args):
- global log
- '''Asynchronous connection handler. Pushes data from socket
- into command queue linewise'''
- try:
- while True:
- try:
- leftovers.append(conn.recv(4096).decode(errors='replace'))
- if len(leftovers[-1]) == 0:
- log.info("socket was closed")
- # FIXME try to reconnect
- sys.exit(1)
- except UnicodeDecodeError as e:
- continue
- except:
- pass
- data = "".join(leftovers)
- del leftovers[:]
- lines = data.split('\n')
- for line in lines[:-1]:
- log.debug("got line: %r", line)
- line = line.strip()
- command_queue.put((line, conn))
- if lines[-1] != '':
- log.debug("remaining %r", lines[-1])
- leftovers.append(lines[-1])
- return True
- def on_loop():
- global command_queue
- '''Command handler. Processes commands in the command queue whenever
- nothing else is happening (registered as GObject idle callback)'''
- if command_queue.empty():
- return True
- line, requestor = command_queue.get()
- words = line.split()
- if len(words) < 1:
- return True
- signal = words[0]
- args = words[1:]
- log.info('received signal %s, dispatching', signal)
- if signal not in signal_handlers:
- return True
- for handler in signal_handlers[signal]:
- cb = handler['cb']
- if 'one' in handler and handler['one']:
- log.debug('removing one-time handler')
- del signal_handlers[signal]
- cb(*args)
- return True
- def send(command, *args):
- global conn, log
- if len(args) > 0:
- command += ' '+(' '.join(args))
- command += '\n'
- conn.send(command.encode('ascii'))
- def on(signal, cb):
- if signal not in signal_handlers:
- signal_handlers[signal] = []
- signal_handlers[signal].append({'cb': cb})
- def one(signal, cb):
- if signal not in signal_handlers:
- signal_handlers[signal] = []
- signal_handlers[signal].append({'cb': cb, 'one': True})
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