Source Code for Module backend.server.rhnImport

  1  # 
  2  # Copyright (c) 2008--2016 Red Hat, Inc. 
  3  # 
  4  # This software is licensed to you under the GNU General Public License, 
  5  # version 2 (GPLv2). There is NO WARRANTY for this software, express or 
  6  # implied, including the implied warranties of MERCHANTABILITY or FITNESS 
  7  # FOR A PARTICULAR PURPOSE. You should have received a copy of GPLv2 
  8  # along with this software; if not, see 
  9  # http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt. 
 10  # 
 11  # Red Hat trademarks are not licensed under GPLv2. No permission is 
 12  # granted to use or replicate Red Hat trademarks that are incorporated 
 13  # in this software or its documentation. 
 14  # 
 15  # 
 16   
 17  import os 
 18  import sys 
 19   
 20  from spacewalk.common.rhnLog import log_debug, log_error 
 21   
 22   
 23 -class Loader: 
 24      # Class that saves the state of imported objects 
 25      _imports = {} 
 26   
 27 -    def load(self, dir, interface_signature='rpcClasses'): 
 28          # The key we use for caching 
 29          root_dir = "/usr/share/rhn" 
 30          key = (dir, root_dir, interface_signature) 
 31   
 32          if key in self._imports: 
 33              return self._imports[key] 
 34   
 35          dirname = "%s/%s" % (root_dir, dir) 
 36   
 37          # We need to import things 
 38          if root_dir is not None and root_dir not in sys.path: 
 39              sys.path.append(root_dir) 
 40   
 41          fromcomps = dir.split('/') 
 42          _imports = {} 
 43   
 44          # Keep track of the modules we've already tried to load, to avoid loading 
 45          # them twice 
 46          modules = [] 
 47          # Load each module (that is not internal - i.e. doesn't start with _) 
 48          for module in os.listdir(dirname): 
 49              log_debug(5, "Attempting to load module %s from %s %s" % ( 
 50                  module, '.'.join(fromcomps), dirname)) 
 51              if module[0] in ('_', '.'): 
 52                  # We consider it 'internal' and we don't load it 
 53                  log_debug(6, "Ignoring module %s" % module) 
 54                  continue 
 55   
 56              # Importing files or directories with . in them is broken, so keep 
 57              # only the first part 
 58              module = module.split('.', 1)[0] 
 59              if module in modules: 
 60                  log_debug(6, "Already tried to load Module %s" % (module, )) 
 61                  continue 
 62   
 63              # Add it to the list, so we don't load it again 
 64              modules.append(module) 
 65   
 66              # We use fromclause to build the full module path 
 67              fromclause = '.'.join(fromcomps + [module]) 
 68   
 69              # Try to import the module 
 70              try: 
 71                  m = __import__(fromclause, {}, {}, [module]) 
 72              except ImportError: 
 73                  e = sys.exc_info()[1] 
 74                  log_error("Error importing %s: %s" % (module, e)) 
 75                  log_debug(6, "Details: sys.path: %s" % (sys.path, )) 
 76                  continue 
 77   
 78              if not hasattr(m, interface_signature): 
 79                  # The module does not support our API 
 80                  log_error("Module %s doesn't support our API" % (module, )) 
 81                  continue 
 82              log_debug(5, "Module %s loaded" % (module, )) 
 83   
 84              _imports[module] = getattr(m, interface_signature) 
 85   
 86          self._imports[key] = _imports 
 87          return _imports 
 88   
 89   
 90 -def load(dir, root_dir=None, interface_signature='rpcClasses'): 
 91      """ 
 92      Load modules (handlers) beneath the handlers/ tree. 
 93   
 94      root_dir: which directory to use as a top-level directory 
 95      """ 
 96   
 97      l = Loader() 
 98      return l.load(dir, interface_signature=interface_signature) 
 99