Verleih.py

#!/usr/bin/python2
# -*- coding: utf-8 -*-
#
# ACHTUNG: Script ist fuer python2
#
# Starts tornado and Socket for Reading/Writing <-> WebInterface
#
# DONT use CTRL+Z to terminate script, else Port is blocked
#
###
from __future__ import print_function
from subprocess import Popen
import threading, time, sys, os.path
try:
    import SocketServer as socketserver
except ImportError:
    import socketserver
try:
    import cymysql
except ImportError:
    print("ERROR: You must install cymysql Module: sudo apt-get install python-pip && sudo pip install cymysql")
    exit()

#-------------------------------------------------------------------
DEBUG = True
#DEBUG = False

HID_device = '/dev/hidraw0'
HID_Script = 'barcode.py'

SocketHost = "0.0.0.0"
SocketPort = 7060

WebSocket_Script = 'websocket.py'

# Specify Settings for MySQL
mysqlHost = 'localhost'
mysqlPort = '3306'
mysqlLogin = 'root'
mysqlPass = 'raspberry'
mysqlENABLE = True
#mysqlENABLE = False
#-------------------------------------------------------------------

# thread docu: http://www.tutorialspoint.com/python/python_multithreading.htm
# socketserver docu: https://docs.python.org/2/library/socketserver.html
# tornado & serial docu: http://forums.lantronix.com/showthread.php?p=3131
# psutil: https://github.com/giampaolo/psutil

#-------------------------------------------------------------------
# Dictionary docu: http://www.tutorialspoint.com/python/python_dictionary.htm
dictionary = {}
dictionary['processing'] = None
dictionary['HID_process'] = None
dictionary['WS_process'] = None
currentTools = {};
#-------------------------------------------------------------------


try:
    DEBUG
except NameError:
    DEBUG = False

if DEBUG:
    print("Enabling DEBUG mode!")
else:
    print("Disabling DEBUG mode!")


def printD(message):
    if DEBUG:
        print(message)

def signal_handler(signal, frame):
    print('Script Interrupted! (Control-C)')
    kill_subProcesses()
    sys.exit()

#http://www.gossamer-threads.com/lists/python/python/375364
def awk_it(instring,index,delimiter=" "):
    try:
        return [instring,instring.split(delimiter)[index-1]][max(0,min(1,index))]
    except:
        return ""

def check_pid(pid):
    """ Check For the existence of a unix pid. """
    if os.path.exists("/proc/%d"%pid):
        return True
    else:
        return False


def TimedProcessCheck():
    global timedCheck
    pid1, pid2 = (dictionary['HID_process'].pid, dictionary['WS_process'].pid)
    if check_pid(pid1) == False:
        dictionary['HID_process'] = Popen('python '+ HID_Script +' '+ HID_device, shell=True)
    if check_pid(pid2) == False:
        dictionary['WS_process'] = Popen('python '+ WebSocket_Script, shell=True)
    timedCheck = threading.Timer( 2.0, TimedProcessCheck )
    timedCheck.start()

def kill_subProcesses():
    try:
        if timedCheck: timedCheck.cancel()
        dictionary['HID_process'].terminate()
        dictionary['WS_process'].terminate()
    except:
        pass

def get_MySQL_Data(ID, Type="tool"):
    con=result = None
    con = cymysql.connect(host=mysqlHost, port=int(mysqlPort), user=mysqlLogin, passwd=mysqlPass)
    cur = con.cursor()
    cur.execute("USE werkzeugausgabe;")
    con.commit()
    if Type == "user":
        cur.execute('SELECT name FROM users WHERE uid="%s";' % ID)
    elif Type == "tool":
        cur.execute('SELECT tid,name FROM tools WHERE tid="%s";' % ID)
    con.commit()
    result = cur.fetchall()
    return result

def update_MySQL_Data(tid, anzahl, ausleiher):
    con=result = None
    con = cymysql.connect(host=mysqlHost, port=int(mysqlPort), user=mysqlLogin, passwd=mysqlPass)
    cur = con.cursor()
    cur.execute("USE werkzeugausgabe;")
    con.commit()
    cur.execute('SELECT anzahl FROM tools WHERE tid="%s";' % tid)
    row = cur.fetchone()
    if row:
        anzahl = int(row[0]) - int(anzahl)
    cur.execute('UPDATE tools SET anzahl="%s", ausleiher="%s" WHERE tid="%s";' % (anzahl, ausleiher, tid))
    con.commit()


### Parse data from WebSocket or SocketServer
#required format-> command:value
def RequestHandler(requestlist):
    returnlist = ""
    for request in requestlist:
        request =  request.strip()
        requestsplit = request.split(':')
        requestsplit.append("dummy")
        command = requestsplit[0]
        value = requestsplit[1]
        if value == "dummy":
            value = "0"
        if command == "localping":
            returnlist += "\n localping:ok"

        elif command == "BARCODE":
            BARCODE = ':'.join(requestsplit[1:])
            #verify data
            if dictionary['processing'] == "get_user":
                data = get_MySQL_Data(BARCODE, Type="user")
                if not data:
                    returnlist += "\n get_user:UNKNOWN_USER"
                else:
                    returnlist += "\n get_user:" + str(data[0][0])
            elif dictionary['processing'] == "get_tool":
                data = get_MySQL_Data(BARCODE, Type="tool")
                if not data:
                    returnlist += "\n get_tool:UNKNOWN_TOOL"
                else:
                    returnlist += "\n get_tool:" + str(data[0][0] + ";" +str(data[0][1]))

        elif command == "get_user":
            dictionary['processing'] = command
            returnlist += "\n get_user:OK"

        elif command == "get_tool":
            dictionary['processing'] = command
            returnlist += "\n get_tool:OK"

        elif command.find("write_database") != '-1':
            i = 1
            j = 0
            valuesplit = value.split(',')
            while i < len(valuesplit):
                toolstring = valuesplit[0].lstrip() + ";" + valuesplit[i]
                toolstringsplit = toolstring.split(';')
                update_MySQL_Data(toolstringsplit[1], toolstringsplit[2], toolstringsplit[0])
                i = i + 1
    return returnlist

#socket server <- barcode scanner (only one way)
class ThreadedTCPRequestHandler(socketserver.StreamRequestHandler):
    def handle(self):
        # self.rfile is a file-like object created by the handler;
        # we can now use e.g. readline() instead of raw recv() calls
        self.data = self.rfile.readline().strip()
        printD("SocketRequest: {}".format(self.data))
        try:
            self.wfile.write(RequestHandler(self.data))
        except Exception as error:
            print("Error in ThreadedTCPRequestHandler: " + str(error))
        except (KeyboardInterrupt, SystemExit):
            sys.exit()

class ThreadedTCPServer(socketserver.ThreadingMixIn, socketserver.TCPServer):
    pass


if __name__ == "__main__":
    try:
        # Start Child Processes for Scripts
        dictionary['HID_process'] = Popen('python '+ HID_Script +' '+ HID_device, shell=True)
        dictionary['WS_process'] = Popen('python '+ WebSocket_Script, shell=True)
        # Start Process-Check-Timer to check that Script are still running
        timedCheck = threading.Timer( 2.0, TimedProcessCheck )
        timedCheck.start()
        # Start a thread with the server - that thread will then start one more thread for each request
        socket_server = ThreadedTCPServer((SocketHost, SocketPort), ThreadedTCPRequestHandler)
        ip, port = socket_server.server_address
        socket_server_thread = threading.Thread(target=socket_server.serve_forever)
        socket_server_thread.start()
        signal.signal(signal.SIGINT, signal_handler)
        signal.signal(signal.SIGTERM, signal_handler)
    except Exception, e1:
        print("Error...: " + str(e1))
    except KeyboardInterrupt:
        print("Schliesse Programm..")
        raise SystemExit("Exiting")
        sys.exit()