Merge branch 'control-server-resilience'

Based on the work made by zuntrax & mithro at cccamp15

4 files changed, 234 insertions, 164 deletions

diff --git a/voctocore/lib/commands.py b/voctocore/lib/commands.py
index 664a6ca..dd4ef0d 100644
--- a/voctocore/lib/commands.py
+++ b/voctocore/lib/commands.py
@@ -2,119 +2,146 @@
 import logging
 import json
 
-
 from lib.config import Config
 from lib.videomix import CompositeModes
+from lib.response import NotifyResponse, OkResponse
 
-class ControlServerCommands():
-	def __init__(self, pipeline):
-		self.log = logging.getLogger('ControlServerCommands')
+def decodeName(items, name_or_id):
+	try:
+		name_or_id = int(name_or_id)
+		if name_or_id < 0 or name_or_id >= len(items):
+			raise IndexError("unknown index %d" % name_or_id)
 
-		self.pipeline = pipeline
-		self.sources = Config.getlist('mix', 'sources')
-		self.blankersources = Config.getlist('stream-blanker', 'sources')
+		return name_or_id
 
-	def decodeSourceName(self, src_name_or_id):
-		if isinstance(src_name_or_id, str):
-			try:
-				return self.sources.index(src_name_or_id)
-			except Exception as e:
-				raise IndexError("source %s unknown" % src_name_or_id)
+	except ValueError as e:
+		try:
+			return items.index(name_or_id)
+
+		except ValueError as e:
+			raise IndexError("unknown name %s" % name_or_id)
+
+def decodeEnumName(enum, name_or_id):
+	try:
+		name_or_id = int(name_or_id)
+		if name_or_id < 0 or name_or_id >= len(enum):
+			raise IndexError("unknown index %d" % name_or_id)
 
-		if src_name_or_id < 0 or src_name_or_id >= len(self.sources):
-			raise IndexError("source %s unknown" % src_name_or_id)
+		return name_or_id
 
-	def encodeSourceName(self, src_id):
+	except ValueError as e:
 		try:
-			return self.sources[src_id]
-		except Exception as e:
-			raise IndexError("source %s unknown" % src_id)
+			return enum[name_or_id]
 
-	def decodeBlankerSourceName(self, src_name_or_id):
-		if isinstance(src_name_or_id, str):
-			try:
-				return self.blankersources.index(src_name_or_id)
-			except Exception as e:
-				raise IndexError("source %s unknown" % src_name_or_id)
+		except KeyError as e:
+			raise IndexError("unknown name %s" % name_or_id)
 
-		if src_name_or_id < 0 or src_name_or_id >= len(self.blankersources):
-			raise IndexError("source %s unknown" % src_name_or_id)
+def encodeName(items, id):
+	try:
+		return items[id]
+	except IndexError as e:
+		raise IndexError("unknown index %d" % id)
 
-	def encodeBlankerSourceName(self, src_id):
-		try:
-			return self.blankersources[src_id]
-		except Exception as e:
-			raise IndexError("source %s unknown" % src_id)
+def encodeEnumName(enum, id):
+	try:
+		return enum(id).name
+	except ValueError as e:
+		raise IndexError("unknown index %d" % id)
 
+class ControlServerCommands(object):
+	def __init__(self, pipeline):
+		self.log = logging.getLogger('ControlServerCommands')
+
+		self.pipeline = pipeline
+
+		self.sources = Config.getlist('mix', 'sources')
+		self.blankerSources = Config.getlist('stream-blanker', 'sources')
+
+	# Commands are defined below. Errors are sent to the clients by throwing
+	# exceptions, they will be turned into messages outside.
 
 	def message(self, *args):
-		return True
+		return NotifyResponse('message', args)
+
+
+	def _get_video_status(self):
+		a = encodeName( self.sources, self.pipeline.vmix.getVideoSourceA() )
+		b = encodeName( self.sources, self.pipeline.vmix.getVideoSourceB() )
+		return [a, b]
+
+	def get_video(self):
+		status = self._get_video_status()
+		return OkResponse('videoStatus', *status)
 
 	def set_video_a(self, src_name_or_id):
-		src_id = self.decodeSourceName(src_name_or_id)
+		src_id = decodeName(self.sources, src_name_or_id)
 		self.pipeline.vmix.setVideoSourceA(src_id)
-		return True
 
-	def get_video_a(self):
-		src_id = self.pipeline.vmix.getVideoSourceA()
-		return (True, self.encodeSourceName(src_id))
+		status = self._get_video_status()
+		return NotifyResponse('videoStatus', *status)
 
 	def set_video_b(self, src_name_or_id):
-		src_id = self.decodeSourceName(src_name_or_id)
+		src_id = decodeName(self.sources, src_name_or_id)
 		self.pipeline.vmix.setVideoSourceB(src_id)
-		return True
 
-	def get_video_b(self):
-		src_id = self.pipeline.vmix.getVideoSourceB()
-		return (True, self.encodeSourceName(src_id))
+		status = self._get_video_status()
+		return NotifyResponse('videoStatus', *status)
+
+
+	def _get_audio_status(self):
+		src_id = self.pipeline.amix.getAudioSource()
+		return encodeName(self.sources, src_id)
+
+	def get_audio(self):
+		status = self._get_audio_status()
+		return OkResponse('audioStatus', status)
 
 	def set_audio(self, src_name_or_id):
-		src_id = self.decodeSourceName(src_name_or_id)
+		src_id = decodeName(self.sources, src_name_or_id)
 		self.pipeline.amix.setAudioSource(src_id)
-		return True
 
-	def get_audio(self):
-		src_id = self.pipeline.amix.getAudioSource()
-		return (True, self.encodeSourceName(src_id))
+		status = self._get_audio_status()
+		return NotifyResponse('audioStatus', status)
 
-	def set_composite_mode(self, composite_mode):
-		try:
-			mode = CompositeModes[composite_mode]
-		except KeyError as e:
-			raise KeyError("composite-mode %s unknown" % composite_mode)
 
+	def _get_composite_status(self):
+		mode = self.pipeline.vmix.getCompositeMode()
+		return encodeEnumName(CompositeModes, mode)
+
+	def get_composite(self):
+		status = self._get_composite_status()
+		return OkResponse('compositeMode', status)
+
+	def set_composite(self, mode_name_or_id):
+		mode = decodeEnumName(CompositeModes, mode_name_or_id)
 		self.pipeline.vmix.setCompositeMode(mode)
-		return True
 
-	def get_composite_mode(self):
-		try:
-			mode = self.pipeline.vmix.getCompositeMode()
-			return (True, mode.name)
-		except Exception as e:
-			raise KeyError("composite-mode %s unknown" % mode)
+		status = self._get_composite_status()
+		return NotifyResponse('compositeMode', status)
 
-	def set_stream_status(self, *args):
-		try:
-			if args[0] == "live":
-				self.pipeline.streamblanker.setBlankSource(None)
-				return True
-			elif args [0] == "blank":
-				src_id = self.decodeBlankerSourceName(args[1])
-				self.pipeline.streamblanker.setBlankSource(src_id)
-				return True
-			else:
-				return (False, "invocation: set_stream_status (live | blank <mode>)")
-		except IndexError as e:
-			return (False, "invocation: set_stream_status (live | blank <mode>)")
+
+	def _get_stream_status(self):
+		blankSource = self.pipeline.streamblanker.blankSource
+		return encodeName(self.blankerSources, blankSource)
 
 	def get_stream_status(self):
-		if self.pipeline.streamblanker.blankSource is None:
-			return (True, "live")
+		status = self._get_stream_status()
+		return OkResponse('streamStatus', status)
 
-		name = self.encodeBlankerSourceName(self.pipeline.streamblanker.blankSource)
-		return (True, "blank " + name)
+	def set_stream_blank(self, source_name_or_id):
+		src_id = decodeName(self.blankerSources, source_name_or_id)
+		self.pipeline.streamblanker.setBlankSource(src_id)
 
-	def get_config(self):
-		confdict = {k: dict(v) for k, v in dict(Config).items()}
-		return (True, json.dumps(confdict))
+		status = self._get_stream_status()
+		return NotifyResponse('streamStatus', status)
 
+	def set_stream_live(self):
+		self.pipeline.streamblanker.setBlankSource(None)
+
+		status = self._get_stream_status()
+		return NotifyResponse('streamStatus', status)
+
+
+	def get_config(self):
+		confdict = {header: dict(section) for header, section in dict(Config).items()}
+		return json.dumps(confdict)
diff --git a/voctocore/lib/controlserver.py b/voctocore/lib/controlserver.py
index 1a75a49..70b9213 100644
--- a/voctocore/lib/controlserver.py
+++ b/voctocore/lib/controlserver.py
@@ -1,9 +1,11 @@
 #!/usr/bin/python3
 import socket, logging, traceback
+from queue import Queue
 from gi.repository import GObject
 
 from lib.commands import ControlServerCommands
 from lib.tcpmulticonnection import TCPMultiConnection
+from lib.response import NotifyResponse, OkResponse
 
 class ControlServer(TCPMultiConnection):
 	def __init__(self, pipeline):
@@ -11,113 +13,135 @@ class ControlServer(TCPMultiConnection):
 		self.log = logging.getLogger('ControlServer')
 		super().__init__(port=9999)
 
+		self.command_queue = Queue()
+
 		self.commands = ControlServerCommands(pipeline)
 
+		GObject.idle_add(self.on_loop)
+
 	def on_accepted(self, conn, addr):
 		'''Asynchronous connection listener. Starts a handler for each connection.'''
-
 		self.log.debug('Setting GObject io-watch on Connection')
-		GObject.io_add_watch(conn, GObject.IO_IN, self.on_data)
+		GObject.io_add_watch(conn, GObject.IO_IN, self.on_data, [''])
+		GObject.io_add_watch(conn, GObject.IO_OUT, self.on_write)
 
-	def on_data(self, conn, *args):
-		'''Asynchronous connection handler. Processes each line from the socket.'''
-		# construct a file-like object fro mthe socket
-		# to be able to read linewise and in utf-8
-		filelike = conn.makefile('rw')
-
-		# read a line from the socket
-		line = ''
+	def on_data(self, conn, _, leftovers, *args):
+		'''Asynchronous connection handler. Pushes data from socket
+		into command queue linewise'''
+		close_after = False
 		try:
-			line = filelike.readline().strip()
-		except Exception as e:
-			self.log.warn("Can't read from socket: %s", e)
-
-		# no data = remote closed connection
-		if len(line) == 0:
+			while True:
+				try:
+					leftovers.append(conn.recv(4096).decode(errors='replace'))
+					if len(leftovers[-1]) == 0:
+						self.log.info("Socket was closed")
+						leftovers.pop()
+						close_after = True
+						break
+
+				except UnicodeDecodeError as e:
+					continue
+		except BlockingIOError as e:
+			pass
+
+		data = "".join(leftovers)
+		leftovers.clear()
+
+		lines = data.split('\n')
+		for line in lines[:-1]:
+			self.log.debug("Got line: %r", line)
+
+			line = line.strip()
+			# TODO: move quit to on_loop
+			# 'quit' = remote wants us to close the connection
+			if line == 'quit':
+				self.log.info("Client asked us to close the Connection")
+				self.close_connection(conn)
+				return False
+
+			self.command_queue.put((line, conn))
+
+		if close_after:
 			self.close_connection(conn)
 			return False
 
-		# 'quit' = remote wants us to close the connection
-		if line == 'quit':
-			self.log.info("Client asked us to close the Connection")
-			self.close_connection(conn)
-			return False
+		self.log.debug("Remaining %r", lines[-1])
+		leftovers.append(lines[-1])
+		return True
 
-		# process the received line
-		success, msg = self.processLine(conn, line)
+	def on_loop(self):
+		'''Command handler. Processes commands in the command queue whenever
+		nothing else is happening (registered as GObject idle callback)'''
+		if self.command_queue.empty():
+			return True
+		line, requestor = self.command_queue.get()
 
-		# success = False -> error
-		if success == False:
-			# on error-responses the message is mandatory
-			if msg is None:
-				msg = '<no message>'
+		words = line.split()
+		if len(words) < 1:
+			return True
 
-			# respond with 'error' and the message
-			filelike.write('error '+msg+'\n')
-			self.log.info("Function-Call returned an Error: %s", msg)
+		command = words[0]
+		args = words[1:]
 
-			# keep on listening on that connection
-			return True
+		self.log.debug("Processing Command %r with args %s", command, args)
 
-		# success = True and not message
-		if msg is None:
-			# respond with a simple 'ok'
-			filelike.write('ok\n')
-		else:
-			# respond with the returned message
-			filelike.write('ok '+msg+'\n')
+		try:
+			command_function = self.commands.__class__.__dict__[command]
 
-		return True
+		except KeyError as e:
+			response = "error unknown command %s\n" % command
 
-	def processLine(self, conn, line):
-		# split line into command and optional args
-		words = line.split()
-		command = words[0]
-		args = words[1:]
+		else:
+			try:
+				responseObject = command_function(self.commands, *args)
 
-		# log function-call as parsed
-		self.log.info("Read Function-Call from %s: %s( %s )", conn.getpeername(), command, args)
+			except Exception as e:
+				message = str(e) or "<no message>"
+				response = "error %s\n" % message
 
-		# check that the function-call is a known Command
-		if not hasattr(self.commands, command):
-			return False, 'unknown command %s' % command
+			else:
+				if isinstance(responseObject, NotifyResponse):
+					signal = "%s\n" % str(responseObject)
+					for conn, queue in self.currentConnections.items():
+						if conn == requestor:
+							continue
 
+						queue.put(signal)
 
-		try:
-			# fetch the function-pointer
-			f = getattr(self.commands, command)
+				response = "%s\n" % str(responseObject)
 
-			# call the function
-			ret = f(*args)
+		finally:
+			if requestor in self.currentConnections:
+				self.currentConnections[requestor].put(response)
 
-			# signal method call to all other connected clients
-			# only signal set_* commands
-			if command.split('_')[0] in ["set", "message"]:
-				self.signal(conn, command, args)
+		return True
 
-			# if it returned an iterable, probably (Success, Message), pass that on
-			if hasattr(ret, '__iter__'):
-				return ret
-			else:
-				# otherwise construct a tuple
-				return (ret, None)
+	def on_write(self, conn, *args):
+		# TODO: on_loop() is not called as soon as there is a writable socket
+		self.on_loop()
 
-		except Exception as e:
-			self.log.error("Trapped Exception in Remote-Communication: %s", e)
+		try:
+			queue = self.currentConnections[conn]
+		except KeyError:
+			return False
 
-			# In case of an Exception, return that
-			return False, str(e)
+		if queue.empty():
+			return True
 
-	def signal(self, origin_conn, command, args):
-		for conn in self.currentConnections:
-			if conn == origin_conn:
-				continue
+		message = queue.get()
+		try:
+			conn.send(message.encode())
+		except Exception as e:
+			self.log.warn(e)
 
-			self.log.debug(
-				'signaling connection %s the successful '
-				'execution of the command %s',
-				conn.getpeername(), command)
+		return True
 
-			conn.makefile('w').write(
-				"signal %s %s\n" % (command, ' '.join(args))
-			)
+	def notify_all(self, msg):
+		try:
+			words = msg.split()
+			words[-1] = self.commands.encodeSourceName(int(words[-1]))
+			msg = " ".join(words) + '\n'
+			for queue in self.currentConnections.values():
+				queue.put(msg)
+		except Exception as e:
+			self.log.debug("Error during notify: %s", e)
diff --git a/voctocore/lib/response.py b/voctocore/lib/response.py
new file mode 100644
index 0000000..866d5f2
--- /dev/null
+++ b/voctocore/lib/response.py
@@ -0,0 +1,15 @@
+#!/usr/bin/python3
+
+class Response(object):
+	def __init__(self, *args):
+		self.args = args
+
+	def __str__(self):
+		return " ".join(map(str, self.args))
+
+
+class OkResponse(Response):
+	pass
+
+class NotifyResponse(Response):
+	pass
diff --git a/voctocore/lib/tcpmulticonnection.py b/voctocore/lib/tcpmulticonnection.py
index 927ac06..e9caf2c 100644
--- a/voctocore/lib/tcpmulticonnection.py
+++ b/voctocore/lib/tcpmulticonnection.py
@@ -1,5 +1,6 @@
 #!/usr/bin/python3
 import logging, socket
+from queue import Queue
 from gi.repository import GObject
 
 from lib.config import Config
@@ -10,7 +11,7 @@ class TCPMultiConnection(object):
 			self.log = logging.getLogger('TCPMultiConnection')
 
 		self.boundSocket = None
-		self.currentConnections = []
+		self.currentConnections = dict()
 
 		self.log.debug('Binding to Source-Socket on [::]:%u', port)
 		self.boundSocket = socket.socket(socket.AF_INET6)
@@ -24,9 +25,11 @@ class TCPMultiConnection(object):
 
 	def on_connect(self, sock, *args):
 		conn, addr = sock.accept()
+		conn.setblocking(False)
+
 		self.log.info("Incomming Connection from %s", addr)
 
-		self.currentConnections.append(conn)
+		self.currentConnections[conn] = Queue()
 		self.log.info('Now %u Receiver connected', len(self.currentConnections))
 
 		self.on_accepted(conn, addr)
@@ -34,5 +37,6 @@ class TCPMultiConnection(object):
 		return True
 
 	def close_connection(self, conn):
-		self.currentConnections.remove(conn)
+		if conn in self.currentConnections:
+			del(self.currentConnections[conn])
 		self.log.info('Now %u Receiver connected', len(self.currentConnections))