Port VLCPlayer from asyncore/asynchat to Twisted

Rationale: asyncore/asynchat are deprecated since Python 3.6 and
are going to be removed from the standard library from Python 3.10.
It is unclear if these libraries will be picked up by maintainers
and independently published on PyPI. At the moment, we are working
on replacing them, in this commit with Twisted LineReceiver.

Known issues: does not work with GUI. There is a conflict with
qt5reactor -> "QSocketNotifier: Can only be used with threads
started with QThread".

syncplay/players/vlc.py

@@ -1,6 +1,4 @@
 
-import asynchat
-import asyncore
 import os
 import random
 import re
@@ -13,11 +11,81 @@ import urllib.error
 import urllib.parse
 import urllib.request
 
+from twisted.internet.protocol import ClientFactory
+from twisted.protocols.basic import LineReceiver
+
 from syncplay import constants, utils
 from syncplay.messages import getMessage
 from syncplay.players.basePlayer import BasePlayer
 from syncplay.utils import isBSD, isLinux, isWindows, isMacOS
 
+class VLCProtocol(LineReceiver):
+    def __init__(self):
+        self.delimiter = b'\n'
+
+    def lineReceived(self, data):
+        self.factory.vlcHasResponded = True
+        self.factory._playerController.lineReceived(data)
+
+    def sendLine(self, line):
+        if self.factory.connected:
+            if not self.factory.requestedVLCVersion:
+                self.factory.requestedVLCVersion = True
+                self.sendLine("get-vlc-version")
+            # try:
+            lineToSend = line.encode('utf-8') + self.delimiter
+            self.transport.write(lineToSend)
+            if self.factory._playerController._client and self.factory._playerController._client.ui:
+                self.factory._playerController._client.ui.showDebugMessage("player >> {}".format(line))
+            # except:
+                # pass
+        if line == "close-vlc":
+            self.factory._playerController._vlcclosed.set()
+            if not self.factory.connected and not self.factory.timeVLCLaunched:
+                # For circumstances where Syncplay is not connected to VLC and is not reconnecting
+                #try:
+                self.factory._process.terminate()
+                #except:  # When VLC is already closed
+                #    pass
+
+    def connectionMade(self):
+        self.factory.connected = True
+        self.factory._playerController._vlcready.set()
+        self.factory.timeVLCLaunched = None
+        self.factory._playerController.initWhenConnected()
+
+    def connectionLost(self, reason):
+        self.factory.connected = False
+
+
+class VLCClientFactory(ClientFactory):
+    def __init__(self, playerController, vlcHasResponded, vlcLaunchedTime, vlcProcess):
+        self._playerController = playerController
+        self._process = vlcProcess
+        self.requestedVLCVersion = False
+        self.vlcHasResponded = vlcHasResponded
+        self.timeVLCLaunched = vlcLaunchedTime
+        self.connected = False
+
+    def buildProtocol(self, addr):
+        self.protocol = VLCProtocol()
+        self.protocol.factory = self
+        return self.protocol
+
+    def clientConnectionLost(self, connector, reason):
+        if self.timeVLCLaunched and time.time() - self.timeVLCLaunched < constants.VLC_OPEN_MAX_WAIT_TIME:
+            try:
+                self._playerController._client.ui.showDebugMessage("Failed to connect to VLC, but reconnecting as within max wait time")
+            except:
+                pass
+            self._playerController._vlcready.clear()
+            connector.connect()
+        elif self.vlcHasResponded:
+            self._playerController.drop()
+        else:
+            self.vlcHasResponded = True
+            self._playerController.drop(getMessage("vlc-failed-connection").format(constants.VLC_MIN_VERSION))
+
 
 class VlcPlayer(BasePlayer):
     speedSupported = True
@@ -63,21 +131,18 @@ class VlcPlayer(BasePlayer):
         self._vlcclosed = threading.Event()
         self._listener = None
         try:
-            self._listener = self.__Listener(self, playerPath, filePath, args, self._vlcready, self._vlcclosed)
+            self._listener = self.__Listener(self, playerPath, filePath, args, self.reactor)
         except ValueError:
             self._client.ui.showErrorMessage(getMessage("vlc-failed-connection"), True)
             self.reactor.callFromThread(self._client.stop, True,)
             return
-        try:
+
-            self._listener.setDaemon(True)
+    def initWhenConnected(self):
-            self._listener.start()
+        if not self._vlcready.wait(constants.VLC_OPEN_MAX_WAIT_TIME):
-            if not self._vlcready.wait(constants.VLC_OPEN_MAX_WAIT_TIME):
+            self._vlcready.set()
-                self._vlcready.set()
+            self._client.ui.showErrorMessage(getMessage("vlc-failed-connection"), True)
-                self._client.ui.showErrorMessage(getMessage("vlc-failed-connection"), True)
+            self.reactor.callFromThread(self._client.stop, True,)
-                self.reactor.callFromThread(self._client.stop, True,)
+        self.reactor.callFromThread(self._client.initPlayer, self,)
-            self.reactor.callFromThread(self._client.initPlayer, self,)
-        except:
-            pass
 
     def _fileUpdateClearEvents(self):
         self._durationAsk.clear()
@@ -326,13 +391,15 @@ class VlcPlayer(BasePlayer):
             self.reactor.callFromThread(self._client.ui.showErrorMessage, dropErrorMessage, True)
         self.reactor.callFromThread(self._client.stop, False,)
 
-    class __Listener(threading.Thread, asynchat.async_chat):
+
-        def __init__(self, playerController, playerPath, filePath, args, vlcReady, vlcClosed):
+    class __Listener():
+        def __init__(self, playerController, playerPath, filePath, args, reactor):
             self.__playerController = playerController
-            self.requestedVLCVersion = False
+            self.reactor = reactor
             self.vlcHasResponded = False
             self.oldIntfVersion = None
             self.timeVLCLaunched = None
+
             call = [playerPath]
             if filePath:
                 if utils.isASCII(filePath):
@@ -341,27 +408,27 @@ class VlcPlayer(BasePlayer):
                     call.append(self.__playerController.getMRL(filePath))
             if isLinux():
                 if 'snap' in playerPath:
-                    playerController.vlcIntfPath = '/snap/vlc/current/usr/lib/vlc/lua/intf/'
+                    self.__playerController.vlcIntfPath = '/snap/vlc/current/usr/lib/vlc/lua/intf/'
-                    playerController.vlcIntfUserPath = os.path.join(os.getenv('HOME', '.'), "snap/vlc/current/.local/share/vlc/lua/intf/")
+                    self.__playerController.vlcIntfUserPath = os.path.join(os.getenv('HOME', '.'), "snap/vlc/current/.local/share/vlc/lua/intf/")
                 else:
-                    playerController.vlcIntfPath = "/usr/lib/vlc/lua/intf/"
+                    self.__playerController.vlcIntfPath = "/usr/lib/vlc/lua/intf/"
-                    playerController.vlcIntfUserPath = os.path.join(os.getenv('HOME', '.'), ".local/share/vlc/lua/intf/")
+                    self.__playerController.vlcIntfUserPath = os.path.join(os.getenv('HOME', '.'), ".local/share/vlc/lua/intf/")
             elif isMacOS():
-                playerController.vlcIntfPath = "/Applications/VLC.app/Contents/MacOS/share/lua/intf/"
+                self.__playerController.vlcIntfPath = "/Applications/VLC.app/Contents/MacOS/share/lua/intf/"
-                playerController.vlcIntfUserPath = os.path.join(
+                self.__playerController.vlcIntfUserPath = os.path.join(
                     os.getenv('HOME', '.'), "Library/Application Support/org.videolan.vlc/lua/intf/")
             elif isBSD():
                 # *BSD ports/pkgs install to /usr/local by default.
                 # This should also work for all the other BSDs, such as OpenBSD or DragonFly.
-                playerController.vlcIntfPath = "/usr/local/lib/vlc/lua/intf/"
+                self.__playerController.vlcIntfPath = "/usr/local/lib/vlc/lua/intf/"
-                playerController.vlcIntfUserPath = os.path.join(os.getenv('HOME', '.'), ".local/share/vlc/lua/intf/")
+                self.__playerController.vlcIntfUserPath = os.path.join(os.getenv('HOME', '.'), ".local/share/vlc/lua/intf/")
             elif "vlcportable.exe" in playerPath.lower():
-                playerController.vlcIntfPath = os.path.dirname(playerPath).replace("\\", "/") + "/App/vlc/lua/intf/"
+                self.__playerController.vlcIntfPath = os.path.dirname(playerPath).replace("\\", "/") + "/App/vlc/lua/intf/"
-                playerController.vlcIntfUserPath = playerController.vlcIntfPath
+                self.__playerController.vlcIntfUserPath = playerController.vlcIntfPath
             else:
-                playerController.vlcIntfPath = os.path.dirname(playerPath).replace("\\", "/") + "/lua/intf/"
+                self.__playerController.vlcIntfPath = os.path.dirname(playerPath).replace("\\", "/") + "/lua/intf/"
-                playerController.vlcIntfUserPath = os.path.join(os.getenv('APPDATA', '.'), "VLC\\lua\\intf\\")
+                self.__playerController.vlcIntfUserPath = os.path.join(os.getenv('APPDATA', '.'), "VLC\\lua\\intf\\")
-            playerController.vlcModulePath = playerController.vlcIntfPath + "modules/?.luac"
+            self.__playerController.vlcModulePath = self.__playerController.vlcIntfPath + "modules/?.luac"
             def _createIntfFolder(vlcSyncplayInterfaceDir):
                 self.__playerController._client.ui.showDebugMessage("Checking if syncplay.lua intf directory exists")
                 from pathlib import Path
@@ -389,11 +456,11 @@ class VlcPlayer(BasePlayer):
                                     return True
                 self.__playerController._client.ui.showDebugMessage("Up-to-dateness checks failed, so copy the file.")
                 return True
-            if _intfNeedsUpdating(os.path.join(playerController.vlcIntfUserPath, "syncplay.lua")):
+            if _intfNeedsUpdating(os.path.join(self.__playerController.vlcIntfUserPath, "syncplay.lua")):
                 try:
-                    _createIntfFolder(playerController.vlcIntfUserPath)
+                    _createIntfFolder(self.__playerController.vlcIntfUserPath)
                     copyForm = utils.findResourcePath("syncplay.lua")
-                    copyTo = os.path.join(playerController.vlcIntfUserPath, "syncplay.lua")
+                    copyTo = os.path.join(self.__playerController.vlcIntfUserPath, "syncplay.lua")
                     self.__playerController._client.ui.showDebugMessage("Copying VLC Lua Interface from '{}' to '{}'".format(copyForm, copyTo))
                     import shutil
                     if os.path.exists(copyTo):
@@ -401,23 +468,21 @@ class VlcPlayer(BasePlayer):
                     shutil.copyfile(copyForm, copyTo)
                     os.chmod(copyTo, 0o755)
                 except Exception as e:
-                    playerController._client.ui.showErrorMessage(e)
+                    self.__playerController._client.ui.showErrorMessage(e)
                     return
             if isLinux():
-                playerController.vlcDataPath = "/usr/lib/syncplay/resources"
+                self.__playerController.vlcDataPath = "/usr/lib/syncplay/resources"
             else:
-                playerController.vlcDataPath = utils.findWorkingDir() + "\\resources"
+                self.__playerController.vlcDataPath = utils.findWorkingDir() + "\\resources"
-            playerController.SLAVE_ARGS.append('--data-path={}'.format(playerController.vlcDataPath))
+            self.__playerController.SLAVE_ARGS.append('--data-path={}'.format(self.__playerController.vlcDataPath))
-            playerController.SLAVE_ARGS.append(
+            self.__playerController.SLAVE_ARGS.append(
                 '--lua-config=syncplay={{modulepath=\"{}\",port=\"{}\"}}'.format(
-                    playerController.vlcModulePath, str(playerController.vlcport)))
+                    self.__playerController.vlcModulePath, str(self.__playerController.vlcport)))
 
-            call.extend(playerController.SLAVE_ARGS)
+            call.extend(self.__playerController.SLAVE_ARGS)
             if args:
                 call.extend(args)
 
-            self._vlcready = vlcReady
-            self._vlcclosed = vlcClosed
             self._vlcVersion = None
 
             if isWindows() and getattr(sys, 'frozen', '') and getattr(sys, '_MEIPASS', '') is not None:  # Needed for pyinstaller --onefile bundle
@@ -438,11 +503,11 @@ class VlcPlayer(BasePlayer):
                         if "Hosting Syncplay" in line:
                             break
                         elif "Couldn't find lua interface" in line:
-                            playerController._client.ui.showErrorMessage(
+                            self.__playerController._client.ui.showErrorMessage(
                                 getMessage("vlc-failed-noscript").format(line), True)
                             break
                         elif "lua interface error" in line:
-                            playerController._client.ui.showErrorMessage(
+                            self.__playerController._client.ui.showErrorMessage(
                                 getMessage("media-player-error").format(line), True)
                             break
             if not isMacOS():
@@ -451,48 +516,13 @@ class VlcPlayer(BasePlayer):
                 vlcoutputthread = threading.Thread(target=self.handle_vlcoutput, args=())
                 vlcoutputthread.setDaemon(True)
                 vlcoutputthread.start()
-            threading.Thread.__init__(self, name="VLC Listener")
+            self.__playerController._vlcready.clear()
-            asynchat.async_chat.__init__(self)
+            self._factory = VLCClientFactory(self.__playerController, self.vlcHasResponded, self.timeVLCLaunched, self.__process)
-            self.set_terminator(b'\n')
+            self.reactor.connectTCP('localhost', self.__playerController.vlcport, self._factory)
-            self._ibuffer = []
-            self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
-            self._sendingData = threading.Lock()
 
         def _shouldListenForSTDOUT(self):
             return not isWindows()
 
-        def initiate_send(self):
-            with self._sendingData:
-                asynchat.async_chat.initiate_send(self)
-
-        def run(self):
-            self._vlcready.clear()
-            self.connect(('localhost', self.__playerController.vlcport))
-            asyncore.loop()
-
-        def handle_connect(self):
-            asynchat.async_chat.handle_connect(self)
-            self._vlcready.set()
-            self.timeVLCLaunched = None
-
-        def collect_incoming_data(self, data):
-            self._ibuffer.append(data)
-
-        def handle_close(self):
-            if self.timeVLCLaunched and time.time() - self.timeVLCLaunched < constants.VLC_OPEN_MAX_WAIT_TIME:
-                try:
-                    self.__playerController._client.ui.showDebugMessage("Failed to connect to VLC, but reconnecting as within max wait time")
-                except:
-                    pass
-                self.run()
-            elif self.vlcHasResponded:
-                asynchat.async_chat.handle_close(self)
-                self.__playerController.drop()
-            else:
-                self.vlcHasResponded = True
-                asynchat.async_chat.handle_close(self)
-                self.__playerController.drop(getMessage("vlc-failed-connection").format(constants.VLC_MIN_VERSION))
-
         def handle_vlcoutput(self):
             out = self.__process.stderr
             for line in iter(out.readline, ''):
@@ -502,28 +532,5 @@ class VlcPlayer(BasePlayer):
                     break
             out.close()
 
-        def found_terminator(self):
-            self.vlcHasResponded = True
-            self.__playerController.lineReceived(b"".join(self._ibuffer))
-            self._ibuffer = []
-
         def sendLine(self, line):
-            if self.connected:
+            self._factory.protocol.sendLine(line)
-                if not self.requestedVLCVersion:
-                    self.requestedVLCVersion = True
-                    self.sendLine("get-vlc-version")
-                # try:
-                lineToSend = line + "\n"
-                self.push(lineToSend.encode('utf-8'))
-                if self.__playerController._client and self.__playerController._client.ui:
-                    self.__playerController._client.ui.showDebugMessage("player >> {}".format(line))
-                # except:
-                    # pass
-            if line == "close-vlc":
-                self._vlcclosed.set()
-                if not self.connected and not self.timeVLCLaunched:
-                    # For circumstances where Syncplay is not connected to VLC and is not reconnecting
-                    try:
-                        self.__process.terminate()
-                    except:  # When VLC is already closed
-                        pass