sfa/rspecs/version_manager.py

   1 import os
   2 from sfa.util.faults import InvalidRSpec
   3 from sfa.util.sfalogging import logger
   4
   5 class VersionManager:
   6     default_type = 'SFA'
   7     default_version_num = '1'
   8
   9     def __init__(self):
  10         self.versions = []
  11         self.load_versions()
  12
  13     def load_versions(self):
  14         path = os.path.dirname(os.path.abspath( __file__ ))
  15         versions_path = path + os.sep + 'versions'
  16         versions_module_path = 'sfa.rspecs.versions'
  17         valid_module = lambda x: os.path.isfile(os.sep.join([versions_path, x])) \
  18                         and not x.endswith('.pyc') and x not in ['__init__.py']
  19         files = [f for f in os.listdir(versions_path) if valid_module(f)]
  20         for filename in files:
  21             basename = filename.split('.')[0]
  22             module_path = versions_module_path +'.'+basename
  23             module = __import__(module_path, fromlist=module_path)
  24             for attr_name in dir(module):
  25                 attr = getattr(module, attr_name)
  26                 if hasattr(attr, 'version'):
  27                     self.versions.append(attr)
  28
  29     def _get_version(self, type, version_num=None, content_type=None):
  30         retval = None
  31         for version in self.versions:
  32             if type is None or type.lower() == version.type.lower():
  33                 if version_num is None or version_num == version.version:
  34                     if content_type is None or content_type.lower() == version.content_type.lower():
  35                         retval = version
  36         if not retval:
  37             raise InvalidRSpec("No such version format: %s version: %s type:%s "% (type, version_num, content_type))
  38         return retval
  39
  40     def get_version(self, version=None):
  41         retval = None
  42         if isinstance(version, dict):
  43             retval =  self._get_version(version.get('type'), version.get('version_num'), version.get('content_type'))
  44         elif isinstance(version, basestring):
  45             version_parts = version.split(' ')
  46             num_parts = len(version_parts)
  47             type = version_parts[0]
  48             version_num = None
  49             content_type = None
  50             if num_parts > 1:
  51                 version_num = version_parts[1]
  52             if num_parts > 2:
  53                 content_type = version_parts[2]
  54             retval = self._get_version(type, version_num, content_type)
  55         else:
  56             logger.info("Unable to parse rspec version, using default")
  57             retval = self._get_version(self.default_type, self.default_version_num)
  58
  59         return retval
  60
  61     def get_version_by_schema(self, schema):
  62         retval = None
  63         for version in self.versions:
  64             if schema == version.schema:
  65                 retval = version
  66         if not retval:
  67             raise InvalidRSpec("Unkwnown RSpec schema: %s" % schema)
  68         return retval
  69
  70 if __name__ == '__main__':
  71     v = VersionManager()
  72     print v.versions
  73     print v.get_version('sfa 1')
  74     print v.get_version('protogeni 2')
  75     print v.get_version('protogeni 2 advertisement')
  76     print v.get_version_by_schema('http://www.protogeni.net/resources/rspec/2/ad.xsd')
  77