pli/importutils.py

   1 #=======================================================================
   2
   3 __version__ = '''0.0.19'''
   4 __sub_version__ = '''20040501170358'''
   5 __copyright__ = '''(c) Alex A. Naanou 2003'''
   6
   7
   8 #-----------------------------------------------------------------------
   9
  10 from __future__ import generators
  11
  12 import os
  13 import sys
  14 import imp
  15
  16
  17 #-----------------------------------------------------------------------
  18
  19 PY_SUFFIXES = imp.get_suffixes()
  20
  21
  22 #-----------------------------------------------------------------------
  23 #-----------------------------------------------ImportDependencyError---
  24 class ImportDependencyError(Exception):
  25         '''
  26         '''
  27
  28
  29
  30 #-----------------------------------------------------------------------
  31 #--------------------------------------------------------_load_module---
  32 # NOTE: this is a potential log/aspect point...
  33 def _load_module(package_dir, mod_name, name_prefix=None):
  34         '''
  35         '''
  36         mod_dat = ()
  37         mod_legal_name = name_prefix in (None, '') \
  38                                                 and mod_name or name_prefix + '.' + mod_name
  39         # import...
  40         try:
  41                 # restrict the import path to avoid uncontrolled imports...
  42                 mod_dat = imp.find_module(mod_name, [package_dir])
  43                 # check if the module is loaded...
  44                 if mod_legal_name in sys.modules:
  45                         return mod_name, sys.modules[mod_name]
  46                 # load the module...
  47 ##              module = imp.load_module(mod_name, *mod_dat)
  48                 module = imp.load_module(mod_legal_name, *mod_dat)
  49                 # cleanup...
  50                 if len(mod_dat) > 1 and mod_dat[0] != None:
  51                         mod_dat[0].close()
  52                 return mod_name, module
  53         except ImportError:
  54                 # cleanup... (is this needed???)
  55                 if len(mod_dat) > 1 and mod_dat[0] != None:
  56                         mod_dat[0].close()
  57                 return mod_name, None
  58
  59
  60 #--------------------------------------------------ispythonimportable---
  61 def ispythonimportable(package_dir, name):
  62         '''
  63         this will test if the module name is importable from package_dir.
  64         '''
  65         mod_path = os.path.join(package_dir, name)
  66         # is directory and contains __init__.py?
  67         if os.path.isdir(mod_path) and \
  68                         True in [ os.path.exists(os.path.join(mod_path, '__init__' + ext[0])) \
  69                                           for ext in PY_SUFFIXES ]:
  70                 return True
  71         else:
  72                 # is file -> is .py[cod]...
  73                 return True in [ os.path.exists(os.path.join(mod_path, ext[0])) \
  74                                                  for ext in PY_SUFFIXES ]
  75         return False
  76
  77
  78 #---------------------------------------------------------packageiter---
  79 def packageiter(package_dir, disable_file='disabled.txt', \
  80                                 disabled_packages=None, notimportable=None, ignore_modules=()):
  81         '''\
  82
  83         This will return importable (and enabled) package names (without importing).
  84         this will return the names of all packages/modules under a given path (package_dir),
  85         not containing the "disabled.txt" file (disable_file), one per iteration.
  86
  87         optional side-effects:
  88                 disabled_packages       : if given, will contain the names of disabled modules
  89                                                           (e.g. modules that contained the "disabled.txt" file
  90                                                           (see above)).
  91                 NOTE: the above two parameters MUST either be of list type or None.
  92         '''
  93         # some sanity checks...
  94         if disabled_packages != None and type(disabled_packages) != list:
  95                 raise TypeError, 'disabled_packages must either be of list type or None (got type "%s").' % type(disabled_packages)
  96         if notimportable != None and type(notimportable) != list:
  97                 raise TypeError, 'notimportable must either be of list type or None (got type "%s").' % type(notimportable)
  98         # start the work...
  99         loaded_packages = {}
 100         for mod in os.listdir(package_dir):
 101 ##              # skip __init__.*
 102 ##              if mod.startswith('__init__.'):
 103 ##                      continue
 104                 # get mod name...
 105                 mod_name = mod.split('.', 1)[0]
 106                 #
 107                 if mod_name in ignore_modules:
 108                         continue
 109                 # include each name only once...
 110                 if mod_name not in loaded_packages.keys() + ['']:
 111                         # skip disabled plugins...
 112                         if os.path.exists(os.path.join(package_dir, mod_name, disable_file)):
 113                                 if disabled_packages != None:
 114                                         disabled_packages += [mod_name]
 115                                 continue
 116                         if ispythonimportable(package_dir, mod_name):
 117                                 yield mod_name
 118                         elif notimportable != None:
 119                                 notimportable += [mod_name]
 120 ##                      yield mod_name
 121
 122
 123 #---------------------------------------------------getpackagedepends---
 124 def getpackagedepends(package_dir, mod_name, dependency_file='depends.txt', forbidden_chars=' -+=&*()^%$#@!~`,.'):
 125         '''
 126         '''
 127         # see if the dependency file exists...
 128         if not os.path.exists(os.path.join(package_dir, mod_name, dependency_file)):
 129                 return []
 130         dep_file = open(os.path.join(package_dir, mod_name, dependency_file))
 131         # parse dependency file...
 132         deps = [ s.lstrip().split('#')[0].rstrip() \
 133                                 for s in dep_file \
 134                                 if s.split('#')[0].lstrip() != '' ]
 135         dep_file.close()
 136         # check for correctness...
 137         if [ s for s in deps if True in [ c in s for c in forbidden_chars ] ]:
 138                 raise ImportDependencyError, 'dependency file format error.'
 139         return deps
 140
 141
 142
 143 #-----------------------------------------------------------------------
 144 #---------------------------------------------------importpackageiter---
 145 # TODO make this return more specific error data (e.g. name, exception,
 146 #      traceback...).
 147 def importpackageiter(package_dir, disable_file='disabled.txt', err_names=None,\
 148                                                 disabled_packages=None, notimportable=None, \
 149                                                 ignore_modules=(), name_prefix=None):
 150         '''\
 151
 152         This is an import iterator.
 153         this will import all packages/modules under a given path (package_dir),
 154         not containing the "disabled.txt" file (disable_file), one per iteration, and
 155         will return a tuple containing the module name and its object.
 156
 157         optional side-effects:
 158                 err_names                       : if given, will contain the names of modules that
 159                                                           generated ImportError.
 160                 disabled_packages       : if given, will contain the names of disabled modules
 161                                                           (e.g. modules that contained the "disabled.txt" file
 162                                                           (see above)).
 163                 NOTE: the above two parameters MUST either be of list type or None.
 164         '''
 165         # some sanity checks...
 166         if err_names != None and type(err_names) != list:
 167                 raise TypeError, 'err_names must either be of list type or None (got type "%s").' % type(err_names)
 168         # start the work...
 169         for mod_name in packageiter(package_dir, disable_file, disabled_packages, notimportable, ignore_modules):
 170                 mod_name, module = _load_module(package_dir, mod_name, name_prefix)
 171                 if module != None:
 172                         yield mod_name, module
 173                 elif err_names != None:
 174                         err_names += [mod_name]
 175
 176
 177
 178 #-------------------------------------------importdependspackagesiter---
 179 # TODO make this a generic dependency checker (objutils ???)
 180 def importdependspackagesiter(package_dir, disable_file='disabled.txt',\
 181                                                                 dependency_file='depends.txt', err_names=None,\
 182                                                                 disabled_packages=None, notimportable=None, \
 183                                                                 ignore_modules=(), name_prefix=None):
 184         '''\
 185
 186         This will import the modules in order of dependency.
 187         '''
 188         # helper function...
 189         def _loaddependsiter(path, name, wait_lst, loaded_packages, err_names=None):
 190                 '''
 191                 '''
 192                 if name not in loaded_packages:
 193                         name, mod = _load_module(path, name, name_prefix)
 194                         if mod == None and err_names != None:
 195                                 err_names += [name]
 196                         else:
 197                                 loaded_packages[name] = mod
 198                                 yield name, mod
 199                 dependees = wait_lst.pop(name, [])
 200                 for name in dependees:
 201                         # if module does not need anything else load
 202                         if [ m for m in wait_lst.values() if name in m ]:
 203                                 # skip...
 204                                 continue
 205                         for n, m in _loaddependsiter(path, name, wait_lst, loaded_packages, err_names):
 206                                 yield n, m
 207         # start the work...
 208         loaded_packages = {}
 209         wait_lst = {}
 210         for mod_name in packageiter(package_dir, disable_file, disabled_packages, notimportable, ignore_modules):
 211                 # get deps...
 212                 deps = getpackagedepends(package_dir, mod_name, dependency_file)
 213                 # if all dependencies are loaded load package...
 214                 needs = [ i for i in deps if i not in loaded_packages ]
 215                 # check if we depend on a faulty package...
 216                 err_needs = [ i for i in needs if i in err_names ]
 217                 if err_names != None and err_names:
 218                         raise ImportDependencyError, 'failure in dependencies (failed: %s).' % err_names
 219                 if needs:
 220                         # wait list...
 221                         for mod in needs:
 222                                 if mod in wait_lst:
 223                                         wait_lst[mod] += [mod_name]
 224                                 else:
 225                                         wait_lst[mod] = [mod_name]
 226                 else:
 227                         for n, m in _loaddependsiter(package_dir, mod_name, wait_lst, loaded_packages, err_names):
 228                                 yield n, m
 229         # check if the remainig data in wait list is looping deps...
 230         if wait_lst:
 231                 # TODO do a more thorough check...
 232                 raise ImportDependencyError, 'cyclic or unresolved demendencies in: %s.' % wait_lst
 233
 234
 235
 236 #=======================================================================
 237 #                                            vim:set ts=4 sw=4 nowrap :