import logging import socket import json import sys from queue import Queue from gi.repository import Gtk, 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, ['']) 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 conn.close() Gtk.main_quit() return False 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() log.debug('re-starting on_loop scheduling') GObject.idle_add(on_loop) command_queue.put((line, conn)) if lines[-1] != '': log.debug("remaining %r", lines[-1]) leftovers.append(lines[-1]) return True def on_loop(): '''Command handler. Processes commands in the command queue whenever nothing else is happening (registered as GObject idle callback)''' global command_queue log.debug('on_loop called') if command_queue.empty(): log.debug('command_queue is empty again, stopping on_loop scheduling') return False line, requestor = command_queue.get() words = line.split() if len(words) < 1: log.debug('command_queue is empty again, stopping on_loop scheduling') 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})