serialization.py

   1 #!/usr/bin/env python
   2 #
   3 # This file is part of jack_mixer
   4 #
   5 # Copyright (C) 2006 Nedko Arnaudov <nedko@arnaudov.name>
   6 #
   7 # This program is free software; you can redistribute it and/or modify
   8 # it under the terms of the GNU General Public License as published by
   9 # the Free Software Foundation; version 2 of the License
  10 #
  11 # This program 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 # along with this program; if not, write to the Free Software
  18 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  19
  20 class serialization_backend:
  21     '''Base class for serialization backends'''
  22     def get_root_serialization_object(self, name):
  23         '''Returns serialization object where properties of root object will be serialized to'''
  24         return None                     # this method should never be called for the base class
  25
  26     def get_child_serialization_object(self, name, backend_object):
  27         return None                     # this method should never be called for the base class
  28
  29 class serialization_object_backend:
  30     '''Base class for serialization backend objects where real object properties will be serialized to or unserialized from.'''
  31     def add_property(self, name, value):
  32         '''Serialize particular property'''
  33         pass
  34
  35     def get_childs(self):
  36         pass
  37
  38     def get_properties(self):
  39         pass
  40
  41     def serialization_name(self):
  42         return None
  43
  44 class serialized_object:
  45     '''Base class for object supporting serialization'''
  46     def serialization_name(self):
  47         return None
  48
  49     def serialize(self, object_backend):
  50         '''Serialize properties of called object into supplied serialization_object_backend'''
  51         pass
  52
  53     def serialization_get_childs(self):
  54         '''Get child objects tha required and support serialization'''
  55         return []
  56
  57     def unserialize_property(self, name, value):
  58         pass
  59
  60     def unserialize_child(self, name):
  61         return None
  62
  63 class serializator:
  64     def __init__(self):
  65         pass
  66
  67     def serialize(self, root, backend):
  68         self.serialize_one(backend, root, backend.get_root_serialization_object(root.serialization_name()))
  69
  70     def unserialize(self, root, backend):
  71         backend_object = backend.get_root_unserialization_object(root.serialization_name())
  72         if backend_object == None:
  73             return False
  74
  75         return self.unserialize_one(backend, root, backend_object)
  76
  77     def unserialize_one(self, backend, object, backend_object):
  78         #print "Unserializing " + repr(object)
  79         properties = backend_object.get_properties()
  80         for name, value in properties.iteritems():
  81             #print "%s = %s" % (name, value)
  82             if not object.unserialize_property(name, value):
  83                 return False
  84
  85         backend_childs = backend_object.get_childs()
  86         for backend_child in backend_childs:
  87             name = backend_child.serialization_name()
  88             child = object.unserialize_child(name)
  89             if not child:
  90                 return False
  91             if not self.unserialize_one(backend, child, backend_child):
  92                 return False
  93
  94         return True
  95
  96     def serialize_one(self, backend, object, backend_object):
  97         object.serialize(backend_object)
  98         childs = object.serialization_get_childs()
  99         for child in childs:
 100             #print "serializing child " + repr(child)
 101             self.serialize_one(backend, child, backend.get_child_serialization_object(child.serialization_name(), backend_object))