Source Code for Module qubx.singleInstance

  1  """Passes command-line args from duplicate processes to the primary one. 
  2   
  3  Copyright 2007-2011 Research Foundation State University of New York  
  4  This file is part of QUB Express.                                           
  5   
  6  QUB Express is free software; you can redistribute it and/or modify           
  7  it under the terms of the GNU General Public License as published by  
  8  the Free Software Foundation, either version 3 of the License, or     
  9  (at your option) any later version.                                   
 10   
 11  QUB Express is distributed in the hope that it will be useful,                
 12  but WITHOUT ANY WARRANTY; without even the implied warranty of        
 13  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         
 14  GNU General Public License for more details.                          
 15   
 16  You should have received a copy of the GNU General Public License,    
 17  named LICENSE.txt, in the QUB Express program directory.  If not, see         
 18  <http://www.gnu.org/licenses/>.                                       
 19   
 20  """ 
 21   
 22  import gobject 
 23  import sys 
 24  from qubx.sock import * 
 25  from qubx.util_types import * 
 26   
 27   
 28 -class SingleInstance(object): 
 29      """ 
 30  SingleInstance(port) 
 31       
 32  Construct this when your app starts, to initiate communication with any duplicates. 
 33  If it is the only instance, this will start a background server, and pass any args 
 34  to mySingleInstance.OnArg(arg). 
 35  If there is an existing instance, this will pass sys.argv[1:] to it. 
 36       
 37  It is your responsibility to check if mySingleInstance.duplicate, and quit. 
 38       
 39  example: 
 40   
 41      >>> import sys, qubx.singleInstance 
 42      >>> mySingleInstance = qubx.singleInstance.SingleInstance(MY_APPS_HIGH_PORT_NUMBER) 
 43      >>> if mySingleInstance.duplicate: 
 44      ...     sys.exit(0) 
 45      >>> print sys.argv[1:] 
 46  """ 
 47 -    def __init__(self, port): 
 48          self.port = port 
 49          self.backlog = [] 
 50          self._OnArg = None 
 51          self.duplicate = False 
 52          try: 
 53              if self.send_args(*sys.argv[1:]): 
 54                  self.duplicate = True 
 55          except: 
 56              self.start_serving() 
 57              for arg in sys.argv[1:]: 
 58                  self.do_OnArg(arg) 
 59 -    def set_OnArg(self, OnArg): 
 60          self._OnArg = OnArg 
 61          for arg in self.backlog: 
 62              gobject.idle_add(self.OnArg, arg) 
 63      OnArg = property(lambda s: s._OnArg, set_OnArg) 
 64 -    def do_OnArg(self, arg): 
 65          if self.OnArg: 
 66              gobject.idle_add(self.OnArg, arg) 
 67          else: 
 68              self.backlog.append(arg) 
 69 -    def start_serving(self): 
 70          self.thread = Thread(target=self.serve) 
 71          self.thread.setDaemon(True) 
 72          self.thread.start() 
 73 -    def serve(self): 
 74          try: 
 75              serv = socket.socket(socket.AF_INET, socket.SOCK_STREAM) 
 76              serv.bind(('localhost', self.port)) 
 77              serv.listen(5) 
 78              while True: 
 79                  client, addr = serv.accept() 
 80                  worker = Thread(target=lambda: self.read(client)) 
 81                  worker.setDaemon(True) 
 82                  worker.start() 
 83          except: 
 84              pass 
 85 -    def read(self, client): 
 86          try: 
 87              chars = [] 
 88              while True: 
 89                  c = client.recv(1) 
 90                  if not c: 
 91                      break 
 92                  if c == '\n': 
 93                      print ''.join(chars) 
 94                      self.do_OnArg(''.join(chars)) 
 95                      chars = [] 
 96                  else: 
 97                      chars.append(c) 
 98          except: 
 99              pass 
100 -    def send_args(self, *args): 
101          sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) 
102          sock.connect(('localhost', self.port)) 
103          sock.settimeout(1.0) 
104          for arg in args: 
105              sock.send("%s\n" % arg) 
106          return len(args) 
107