#!/usr/bin/env python

# -*- coding: utf-8 -*-

# This file is part of Beremiz

# Copyright (C) 2019: Edouard TISSERANT

# See COPYING file for copyrights details.

from __future__ import absolute_import

import errno

from threading import RLock, Timer

try:

from runtime.spawn_subprocess import Popen

except ImportError:

from subprocess import Popen

from twisted.web.server import Site

from twisted.web.resource import Resource

from twisted.internet import reactor

from twisted.web.static import File

from autobahn.twisted.websocket import WebSocketServerFactory, WebSocketServerProtocol

from autobahn.websocket.protocol import WebSocketProtocol

from autobahn.twisted.resource import WebSocketResource

# TODO multiclient :

# session list lock

# svghmi_sessions = []

# svghmi_watchdogs = []

svghmi_session = None

svghmi_watchdog = None

svghmi_send_collect = PLCBinary.svghmi_send_collect

svghmi_send_collect.restype = ctypes.c_int # error or 0

svghmi_send_collect.argtypes = [

ctypes.POINTER(ctypes.c_uint32), # size

ctypes.POINTER(ctypes.c_void_p)] # data ptr

# TODO multiclient : switch to arrays

svghmi_recv_dispatch = PLCBinary.svghmi_recv_dispatch

svghmi_recv_dispatch.restype = ctypes.c_int # error or 0

svghmi_recv_dispatch.argtypes = [

ctypes.c_uint32, # size

ctypes.c_char_p] # data ptr

# TODO multiclient : switch to arrays

class HMISession(object):

def __init__(self, protocol_instance):

global svghmi_session

# Single client :

# Creating a new HMISession closes pre-existing HMISession

if svghmi_session is not None:

svghmi_session.close()

svghmi_session = self

self.protocol_instance = protocol_instance

# TODO multiclient :

# svghmi_sessions.append(self)

# get a unique bit index amont other svghmi_sessions,

# so that we can match flags passed by C->python callback

def close(self):

global svghmi_session

if svghmi_session == self:

svghmi_session = None

self.protocol_instance.sendClose(WebSocketProtocol.CLOSE_STATUS_CODE_NORMAL)

def onMessage(self, msg):

# pass message to the C side recieve_message()

return svghmi_recv_dispatch(len(msg), msg)

# TODO multiclient : pass client index as well

def sendMessage(self, msg):

self.protocol_instance.sendMessage(msg, True)

return 0

class Watchdog(object):

def __init__(self, initial_timeout, interval, callback):

self._callback = callback

self.lock = RLock()

self.initial_timeout = initial_timeout

self.interval = interval

self.callback = callback

with self.lock:

self._start()

def _start(self, rearm=False):

duration = self.interval if rearm else self.initial_timeout

if duration:

self.timer = Timer(duration, self.trigger)

self.timer.start()

else:

self.timer = None

def _stop(self):

if self.timer is not None:

self.timer.cancel()

self.timer = None

def cancel(self):

with self.lock:

self._stop()

def feed(self, rearm=True):

with self.lock:

self._stop()

self._start(rearm)

def trigger(self):

self._callback()

# wait for initial timeout on re-start

self.feed(rearm=False)

class HMIProtocol(WebSocketServerProtocol):

def __init__(self, *args, **kwargs):

self._hmi_session = None

WebSocketServerProtocol.__init__(self, *args, **kwargs)

def onOpen(self):

assert(self._hmi_session is None)

self._hmi_session = HMISession(self)

def onClose(self, wasClean, code, reason):

self._hmi_session = None

def onMessage(self, msg, isBinary):

assert(self._hmi_session is not None)

result = self._hmi_session.onMessage(msg)

if result == 1 : # was heartbeat

if svghmi_watchdog is not None:

svghmi_watchdog.feed()

class HMIWebSocketServerFactory(WebSocketServerFactory):

protocol = HMIProtocol

svghmi_root = None

svghmi_listener = None

svghmi_send_thread = None

def SendThreadProc():

global svghmi_session

size = ctypes.c_uint32()

ptr = ctypes.c_void_p()

res = 0

while True:

res=svghmi_send_collect(ctypes.byref(size), ctypes.byref(ptr))

if res == 0:

# TODO multiclient : dispatch to sessions

if svghmi_session is not None:

svghmi_session.sendMessage(ctypes.string_at(ptr.value,size.value))

elif res == errno.ENODATA:

# this happens when there is no data after wakeup

# because of hmi data refresh period longer than PLC common ticktime

pass

else:

# this happens when finishing

break

def watchdog_trigger():

print("SVGHMI watchdog trigger")

# Called by PLCObject at start

def _runtime_00_svghmi_start():

global svghmi_listener, svghmi_root, svghmi_send_thread

svghmi_root = Resource()

svghmi_root.putChild("ws", WebSocketResource(HMIWebSocketServerFactory()))

svghmi_listener = reactor.listenTCP(8008, Site(svghmi_root))

# start a thread that call the C part of SVGHMI

svghmi_send_thread = Thread(target=SendThreadProc, name="SVGHMI Send")

svghmi_send_thread.start()

# Called by PLCObject at stop

def _runtime_00_svghmi_stop():

global svghmi_listener, svghmi_root, svghmi_send_thread, svghmi_session

if svghmi_session is not None:

svghmi_session.close()

svghmi_root.delEntity("ws")

svghmi_root = None

svghmi_listener.stopListening()

svghmi_listener = None

# plc cleanup calls svghmi_(locstring)_cleanup and unlocks send thread

svghmi_send_thread.join()

svghmi_send_thread = None

class NoCacheFile(File):

def render_GET(self, request):

request.setHeader(b"Cache-Control", b"no-cache, no-store")

return File.render_GET(self, request)

render_HEAD = render_GET