1 # -*- coding: iso-8859-1 -*-
2 # Copyright (C) 2007-2008 CEA/DEN, EDF R&D, OPEN CASCADE
4 # Copyright (C) 2003-2007 OPEN CASCADE, EADS/CCR, LIP6, CEA/DEN,
5 # CEDRAT, EDF R&D, LEG, PRINCIPIA R&D, BUREAU VERITAS
7 # This library is free software; you can redistribute it and/or
8 # modify it under the terms of the GNU Lesser General Public
9 # License as published by the Free Software Foundation; either
10 # version 2.1 of the License.
12 # This library is distributed in the hope that it will be useful,
13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 # Lesser General Public License for more details.
17 # You should have received a copy of the GNU Lesser General Public
18 # License along with this library; if not, write to the Free Software
19 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 # See http://www.salome-platform.org/ or email : webmaster.salome@opencascade.com
24 This module replaces the standard import mechanism with one
25 that filters some imports that can't be done more than once.
27 This is related to the multi study feature that is implemented
28 by using the Python multi interpreter feature.
29 Some modules register objects or classes by calling modules
30 implemented in C. These operations can't be done multiple times.
31 So it's very important to control these imports.
34 - PyQt : import qt calls a C module to register classes
35 - OmniORB : import *_idl calls a C module to register CORBA interfaces
38 - First import the module : import import_hook. This module will
39 replace the original importer mechanism
41 - Next register the module names or pattern names to filter out::
42 import_hook.register_name("a")
43 import_hook.register_pattern(pattern)
45 where pattern is a function with one parameter, the module name
46 to be imported, that returns true or false depending if this module is
47 to be filtered or not.
51 IMPORTANT : Every subinterpretor has its own import_hook module. import_hook is not shared among subinterpretors.
52 The mechanism only works if shared_imported and pattern are shared between all subinterpretors.
53 This is done by calling init_shared_modules().
56 import sys, imp, __builtin__
58 # Keep in shared_imported a copy of dictionnary modules
59 # that need to be imported only once in multi-study context
62 # patterns contains functions that returns 1 or 0 depending if
63 # the module name (argument) must be filtered out or not
64 # These functions are added by calling register_pattern
67 original_import=__builtin__.__import__
69 def register_name(name):
70 if shared_imported.has_key(name):return
71 shared_imported[name]=None
73 def register_pattern(pattern):
74 patterns.append(pattern)
77 """ Indicate if module name is a shared module
78 among multiple interpreters (return value=1)
80 if shared_imported.has_key(name):return 1
81 for pattern in patterns:
82 if pattern(name) : return 1
85 def get_shared_imported(name,fromlist):
86 """ If the module is registered in shared_imported
87 update the sys.modules dict
88 Let the real import be done by original_import
90 module= shared_imported.get(name)
92 #module name is not shared or not already imported
93 #let original_import do the job
96 # module is already imported and shared. Put it in sys.modules and
97 # let original_import finish the job
98 sys.modules[name]=module
100 def get_real_module(mod,name):
101 """Return effective module on import
102 Standard import returns module A on import A.B
103 To get module A.B use get_real_module with name "A.B"
105 components = name.split('.')
106 for comp in components[1:]:
107 mod = getattr(mod, comp)
110 def set_shared_imported(name,module):
111 """ Register a shared module
112 Name can be a dotted name : package
114 shared_imported[name]=module
115 #print "Module %s shared registered" % name,module
117 def import_module(partname, fqname, parent):
118 """ Try to import module fqname
119 It's parent is module parent and has name partname
122 m = sys.modules[fqname]
128 def ensure_fromlist(m, fromlist, recursive=0):
129 """ Return the real modules list to be imported
137 except AttributeError:
140 l.extend(ensure_fromlist(m, all, 1))
142 submod=getattr(m,sub)
143 if type(submod) == type(sys):
144 l.append(("%s.%s" % (m.__name__, sub),submod))
146 subname="%s.%s" % (m.__name__, sub)
147 submod = import_module(sub, subname, m)
149 raise ImportError, "No module named " + subname
150 l.append((subname,submod))
153 def import_hook(name, globals=None, locals=None, fromlist=None, *args):
154 """ Import replacement for sharing modules among multiple interpreters
155 Mostly update sys.modules before doing real import
157 #print "import_hook",name,fromlist
158 m=get_shared_imported(name,fromlist)
160 module= original_import(name, globals, locals, fromlist, *args)
163 #when fromlist is specified, module is the real module
164 #fromlist is a list of possibly dotted name
166 for nam,mod in ensure_fromlist(m, fromlist):
168 set_shared_imported(nam,mod)
170 #when fromlist is not specified and name is a dotted name,
171 # module is the root package not the real module
172 #so we need to retrieve it
173 # note: some modules like xml.dom do not play the rule
174 # (import xml: no attribute dom, but import xml.dom OK)
176 m=get_real_module(module,name)
177 except AttributeError:
180 if type(m) == type(sys) and is_shared(m.__name__):
181 set_shared_imported(m.__name__,m)
185 original_reload=__builtin__.reload
187 def reload_hook(module):
188 if is_shared(module.__name__):
190 return original_reload(module)
192 __builtin__.__import__=import_hook
193 # Reload is not replaced
194 #__builtin__.reload=reload_hook
196 def init_shared_modules(shared_module):
197 global shared_imported, patterns
198 shared_imported=shared_module.shared_imported
199 patterns= shared_module.patterns
200 for k,v in shared_imported.items():
201 if v is not None:sys.modules[k]=v
202 shared_imported["salome_shared_modules"]=shared_module
203 import salome_shared_modules
204 for m in salome_shared_modules.list_modules:
205 m.init_shared_modules()