workspace/plasma/scriptengines/python/plasma_importer.py

   1 #
   2 # Copyright 2008 Simon Edwards <simon@simonzone.com>
   3 #
   4 # This program is free software; you can redistribute it and/or modify
   5 # it under the terms of the GNU Library General Public License as
   6 # published by the Free Software Foundation; either version 2, or
   7 # (at your option) any later version.
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU General Public License for more details
  13 #
  14 # You should have received a copy of the GNU Library General Public
  15 # License along with this program; if not, write to the
  16 # Free Software Foundation, Inc.,
  17 # 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  18 #
  19
  20 import sys
  21 import os
  22 import imp
  23
  24 class PlasmaImporter(object):
  25     def __init__(self):
  26         self.toplevel = {}
  27         self.toplevelcount = {}
  28         sys.path.append('<plasma>')
  29         sys.path_hooks.append(self.hook)
  30         #print("PlasmaImporter.__init__: sys.path:" + repr(sys.path))
  31
  32     def hook(self,path):
  33       if path=='<plasma>':
  34           #print("plasma_thingy:"+ path)
  35           return self
  36       else:
  37           raise ImportError()
  38
  39     def register_top_level(self,name,path):
  40         if name not in self.toplevel:
  41             self.toplevelcount[name] = 1
  42             self.toplevel[name] = path
  43         else:
  44             self.toplevelcount[name] += 1
  45
  46     def unregister_top_level(self,name):
  47         value = self.toplevelcount[name]-1
  48         self.toplevelcount[name] = value
  49         if value==0:
  50             del self.toplevelcount[name]
  51             del self.toplevel[name]
  52             for key in list(sys.modules.keys()):
  53                 if key==name or key.startswith(name+"."):
  54                     del sys.modules[key]
  55
  56     def find_module(self,fullname, path=None):
  57         #print('find_module(%s,%s)' % (fullname,path) )
  58
  59         location = self.find_pymod(fullname)
  60         if location is not None:
  61             #print("Found in " + location[0])
  62             return self
  63         else:
  64             return None
  65
  66     # Find the given module in the plasma directory.
  67     # Result a tuple on success otherwise None. The tuple contains the location
  68     # of the module/package in disk and a boolean indicating if it is a package
  69     # or module
  70     def find_pymod(self,modulename):
  71         parts = modulename.split('.')
  72         toppackage = parts[0]
  73         rest = parts[1:]
  74
  75         if toppackage in self.toplevel:
  76             path = self.toplevel[toppackage]
  77             if len(rest)==0:
  78                 # Simple top level Plasma package
  79                 return (path,True)
  80             else:
  81                 restpath = apply(os.path.join,rest)
  82                 fullpath = os.path.join(path,'contents','code',restpath)
  83                 if os.path.isdir(fullpath):
  84                     return (fullpath,True)
  85                 elif os.path.exists(fullpath+'.py'):
  86                     return (fullpath+'.py',False)
  87         else:
  88             return None
  89
  90     def _get_code(self,location):
  91         return open(location).read()
  92
  93     def load_module(self, fullname):
  94         #print('load_module fullname: '+fullname)
  95
  96         location,ispkg = self.find_pymod(fullname)
  97         #print("Location:"+location)
  98         if ispkg:   # Package dir.
  99             initlocation = os.path.join(location,'__init__.py')
 100             code = None
 101             if os.path.isfile(initlocation):
 102                 #code = self._get_code(initlocation)
 103                 code = open(initlocation)
 104         else:
 105             #code = self._get_code(location)
 106             code = open(location)
 107
 108         mod = sys.modules.setdefault(fullname, imp.new_module(fullname))
 109         mod.__file__ = location #"<%s>" % self.__class__.__name__
 110         mod.__loader__ = self
 111         if ispkg:
 112             mod.__path__ = ["<plasma>"]
 113         if code is not None:
 114             #print("code is:"+code)
 115             try:
 116                 exec code in mod.__dict__
 117             finally:
 118                 code.close()
 119         return mod
 120
 121 #plasma_importer = PlasmaImporter()
 122 #plasma_importer.register_top_level('plasma_pyclock','/home/sbe/devel/python_plasma_2/test/plasma-pyclock')
 123 #from  plasma_pyclock import main