Chain.py

   1 #!/usr/bin/python
   2 # -*- coding: utf-8 -*-
   3 # vim: expandtab:shiftwidth=4:fileencoding=utf-8 :
   4
   5 # Copyright ® 2008 Fulvio Satta
   6 #
   7 # If you want contact me, send an email to Yota_VGA@users.sf.net
   8 #
   9 # This file is part of jcd
  10 #
  11 # jcd is free software; you can redistribute it and/or modify
  12 # it under the terms of the GNU General Public License as published by
  13 # the Free Software Foundation; either version 2 of the License, or
  14 # (at your option) any later version.
  15 #
  16 # jcd is distributed in the hope that it will be useful,
  17 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 # GNU General Public License for more details.
  20 #
  21 # You should have received a copy of the GNU General Public License
  22 # along with this program; if not, write to the Free Software
  23 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  24
  25 #TODO: Test, test, test
  26 #TODO: Polishing
  27
  28 ##########################
  29 ##### IMPORT SECTION #####
  30 ##########################
  31
  32 from Syncronized import Syncronized as _Syncronized
  33 from Syncronized import AutoLock    as _AutoLock
  34
  35 import sys as _sys
  36
  37 ####################################
  38 ##### DEFAULT JUNCTORS SECTION #####
  39 ####################################
  40
  41 #Input junctor for no args reinterpretation
  42 def inputDirectJunctor(args, kwargs):
  43     return (args, kwargs)
  44
  45 #Output junctor for no return reinterpretation
  46 def outputDirectJunctor(ret, args, kwargs):
  47     return ([ret], {})
  48
  49 ################################
  50 ##### MAIN CLASSES SECTION #####
  51 ################################
  52
  53 #A node of the chain
  54 class Node(_Syncronized):
  55     def __init__(self, inputJunctor = inputDirectJunctor, outputJunctor = outputDirectJunctor):
  56         _Syncronized.__init__(self)
  57
  58         self.inputJunctor = inputJunctor
  59         self.outputJunctor = outputJunctor
  60
  61     #Call the node
  62     @_AutoLock
  63     def __call__(self, *args, **kwargs):
  64         rargs, rkwargs = self.inputJunctor(args, kwargs)
  65         return self.outputJunctor(self.work(*rargs, **rkwargs), rargs, rkwargs)
  66
  67     #The work of the node, you must reimplement this
  68     def work(self, *args, **kwargs):
  69         print >> _sys.stderr, 'You must reimplement the work method in the Chain.Node inherited classes!'
  70         raise NotImplemented, 'You must reimplement the work method in the Chain.Node inherited classes!'
  71
  72 #The chain (nodes must be callable, but not strictly Node classes)
  73 class Chain(_Syncronized):
  74     def __init__(self):
  75         _Syncronized.__init__(self)
  76         self.nodes = []
  77
  78     #Call the chain
  79     @_AutoLock
  80     def __call__(self, *args, **kwargs):
  81         rargs, rkwargs = args, kwargs
  82
  83         #Recursively work with the nodes
  84         for node in self.nodes:
  85             rargs, rkwargs = node(*rargs, **rkwargs)
  86
  87         return rargs, rkwargs
  88
  89 ########################
  90 ##### TEST SECTION #####
  91 ########################
  92
  93 if __name__ == '__main__':
  94     class Try1(Node):
  95         def work(self, var):
  96             return var + 1
  97
  98     t1 = Chain()
  99     t1.nodes += [Try1(), Try1()]
 100
 101     import inspect
 102     print inspect.getargspec(Try1().work)
 103
 104     print t1(1)[0][0]