frappy/bin/stringio-server

#!/usr/bin/env python3
# pylint: disable=invalid-name
#  -*- coding: utf-8 -*-
# *****************************************************************************
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free Software
# Foundation; either version 2 of the License, or (at your option) any later
# version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# Module authors:
#   Markus Zolliker <markus.zolliker@psi.ch>
# *****************************************************************************
"""server for a string communicator

Usage:

    bin/stringio-server <communciator> <server port>

open a server on <server port> to communicate with the string based <communicator> over TCP/IP.

Use cases, mainly for test purposes:
- as a T, if the hardware allows only one connection, and more than one is needed
- relay to a communicator not using TCP/IP, if Frappy should run on an other host
- relay to a hardware simulation written as a communicator
"""

import sys
from os import path
import asyncore
import socket
import ast

# Add import path for inplace usage
sys.path.insert(0, path.abspath(path.join(path.dirname(__file__), '..')))

from secop.lib import get_class, formatException

class LineHandler(asyncore.dispatcher_with_send):

    def __init__(self, sock):
        self.buffer = b""
        asyncore.dispatcher_with_send.__init__(self, sock)
        self.crlf = 0

    def handle_read(self):
        data = self.recv(8192)
        if data:
            parts = data.split(b"\n")
            if len(parts) == 1:
                self.buffer += data
            else:
                self.handle_line((self.buffer + parts[0]).decode('latin_1'))
                for part in parts[1:-1]:
                    if part[-1] == b"\r":
                        self.crlf = True
                        part = part[:-1]
                    else:
                        self.crlf = False
                    self.handle_line(part.decode('latin_1'))
                self.buffer = parts[-1]

    def send_line(self, line):
        self.send((line + ("\r\n" if self.crlf else "\n")).encode('latin_1'))


class LineServer(asyncore.dispatcher):

    def __init__(self, host, port, lineHandlerClass):
        asyncore.dispatcher.__init__(self)
        self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
        self.set_reuse_addr()
        self.bind((host, port))
        self.listen(5)
        self.lineHandlerClass = lineHandlerClass

    def handle_accept(self):
        pair = self.accept()
        if pair is not None:
            sock, addr = pair
            print("Incoming connection from %s" % repr(addr))
            self.lineHandlerClass(sock)

    def loop(self):
        asyncore.loop()


class Server(LineServer):

    class Dispatcher:
        def announce_update(self, *_):
            pass

        def announce_update_error(self, *_):
            pass

    def __init__(self, *args, **kwds):
        super().__init__(*args, **kwds)
        self.dispatcher = self.Dispatcher()


class Handler(LineHandler):
    def handle_line(self, line):
        try:
            reply = module.do_communicate(line.strip())
            if verbose:
                print('%-40s | %s' % (line, reply))
        except Exception:
            print(formatException(verbose=True))
        self.send_line(reply)


class Logger:
    def debug(self, *args):
        print(*args)
    info = exception = debug


opts = {'description': 'simulator'}
args = []
for arg in sys.argv[1:]:
    k, sep, v = arg.partition('=')
    if not k:
        args.append(v)
    try:
        v = ast.literal_eval(v)
    except Exception:
        pass
    opts[k] = v
verbose = opts.pop('verbose', False)
opts['cls'] = 'secop_psi.ls370sim.Ls370Sim'
opts['port'] = 4567
if len(args) > 2:
    raise ValueError('do not know about: %s' % ' '.join(args[2:]))
if len(args) == 2:
    opts['port'] = int(args[1])
if len(args) > 0:
    opts['cls'] = args[0]
    args.append(opts)

cls = opts.pop('cls')
port = opts.pop('port')
srv = Server('localhost', int(port), Handler)
module = get_class(cls)(cls, Logger(), opts, srv)
module.earlyInit()
srv.loop()