implement config fetching and switch to async mode

1 files changed, 89 insertions, 22 deletions

diff --git a/voctogui/lib/connection.py b/voctogui/lib/connection.py
index ac7243d..433693d 100644
--- a/voctogui/lib/connection.py
+++ b/voctogui/lib/connection.py
@@ -1,46 +1,113 @@
 #!/usr/bin/python3
 import logging
 import socket
+import json
+import sys
+from queue import Queue
+from gi.repository import GObject
 
 log = logging.getLogger('Connection')
-sock = None
+conn = None
 port = 9999
+command_queue = Queue()
 
 def establish(host):
+	global conn, port, log
+
 	log.info('establishing Connection to %s', host)
-	sock = socket.create_connection( (host, port) )
+	conn = socket.create_connection( (host, port) )
 	log.debug('Connection successful \o/')
-	# TODO: register IO callback here
 
+def fetchServerConfig():
+	global conn, log
 
-def send(command):
-	print("would send command talk to server now and read back the response")
-	filelike = sock.makefile('rw')
-	filelike.write(command + "\n")
-	filelike.flush()
+	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
 
-def on_data(args*):
-	filelike = sock.makefile()
-	line = ''
+	'''Asynchronous connection handler. Pushes data from socket
+	into command queue linewise'''
 	try:
-		line = filelike.readline()
-	except Exception as e:
-		log.warn("Can't read from socket: %s", e)
+		while True:
+			try:
+				leftovers.append(conn.recv(4096).decode(errors='replace'))
+				if len(leftovers[-1]) == 0:
+					log.info("socket was closed")
 
-	if len(line) == 0:
-		close_connection()
-		return False
+					# FIXME try to reconnect
+					sys.exit(1)
 
-	line = line.strip()
+			except UnicodeDecodeError as e:
+				continue
+	except BlockingIOError as e:
+		pass
 
-	process_line(line)
+	data = "".join(leftovers)
+	leftovers.clear()
 
+	lines = data.split('\n')
+	for line in lines[:-1]:
+		log.debug("got line: %r", line)
 
-def process_line(line):
-	msg_type = line.split()[0]
+		line = line.strip()
+		command_queue.put((line, conn))
 
+	log.debug("remaining %r", lines[-1])
+	leftovers.append(lines[-1])
+	return True
 
-def close_connection():
+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)
+
+def send(command):
+	global conn, log
+	conn.send(command)
+
+def on(signal, cb):
 	pass
 
+def one(signal, cb):
+	pass