Source Code for Module Ganga.GPIDev.Base.Filters

  1  # Customization of GPI component object assignment: Component Filters 
  2  # 
  3  # Example of usage: 
  4  # 
  5  #  j.f = 'myfile'  <=>  j.f = File('myfile') 
  6  #  j.application = 'DaVinci' <=> DaVinci() 
  7  # 
  8  #  j = Job() 
  9  #  j2 = Job(j)  <=> copy constructor 
 10  # 
 11  #   
 12  # 
 13  # Semantics: 
 14  #  gpi_proxy.x = v  --> f = select_filter(category_of(x)); f(v,schema_item_of(x)) 
 15  #  gpi_proxy.y = [v1,v2] --> f = select_filter(category_of(x)); [f(v,schema_item_of(y)) for v in [v1,v2]] 
 16  #  x = X(y,...) --> f = select_filter(X._category); f(y,None) 
 17  # 
 18  # Component filters are applied *only* to component properties and they are applied *before* attribute filters. 
 19   
 20  # Component filter has the following signature: 
 21  #     filter(val,item) --> return a GangaObject instance or None if no conversion performed 
 22  # 
 23  #     item is None if the filter is called outside of the attribute assignment context 
 24  #  
 25  # If conversion takes place filter MUST return an object which is an instance (derived) of GangaObject. 
 26   
 27  # Void filter does nothing. This is the default filter if no other default has been defined. 
 28   
 29  from Ganga.Utility.Config import makeConfig 
 30  from Ganga.Utility.Config.Config import ConfigError 
 31   
 32  # test configuration properties 
 33  config = makeConfig('GPIComponentFilters',"""Customization of GPI component object assignment 
 34  for each category there may be multiple filters registered, the one used being defined  
 35  in the configuration file in [GPIComponentFilters] 
 36  e.g: {'datasets':{'lhcbdatasets':lhcbFilter, 'testdatasets':testFilter}...} 
 37  """,is_open=False) 
 38   
 39 -def void_filter(val,item): 
 40      return None 
 41   
 42 -class _ComponentFilterManager: 
 43 -    def __init__(self): 
 44          #for each category there may be multiple filters registered, the one used being defined  
 45          #in the configuration file in [GPIComponentFilters] 
 46          #e.g: {'datasets':{'lhcbdatasets':lhcbFilter, 'testdatasets':testFilter}...} 
 47          self._dict = {} 
 48          self.default = None 
 49           
 50 -    def __setitem__(self,category,filter):         
 51           
 52          if not self._dict.has_key(category): 
 53              self._dict[category] = {} 
 54           
 55          #the filter can be registered as a tuple: ('filtername',filterfunction) 
 56          #or just as a function in which case the function name is used as an alias 
 57          if type(filter)==type(()) and len(filter)>=2: 
 58              filtername = filter[0] 
 59              filterfunc = filter[1]             
 60          else: 
 61              try: 
 62                  filtername = filter.__name__ 
 63                  filterfunc = filter 
 64              except AttributeError,e: 
 65                  raise ValueError('FilterManager: Invalid component filter %s.'%filter) 
 66           
 67          if self._dict[category].has_key(filtername): 
 68              raise ValueError('FilterManager: %s component filter already exists for %s category '%(filtername,category)) 
 69   
 70          if not config.options.has_key(category): 
 71              config.addOption(category, "", "") 
 72          config.overrideDefaultValue(category,filtername) 
 73          self._dict[category][filtername] = filterfunc 
 74   
 75 -    def setDefault(self,filter): 
 76          if self.default: 
 77              raise ValueError('FilterManager: default filter already exists') 
 78   
 79          self.default = filter 
 80   
 81 -    def __getitem__(self,category): 
 82          try: 
 83              filters = self._dict[category] 
 84          except KeyError: 
 85              #no filters registered for this category 
 86              if self.default: return self.default 
 87              return void_filter 
 88           
 89          try: 
 90              filtername = config[category]             
 91              return filters[filtername] 
 92          except ConfigError: 
 93              #if we have only one filter registered for this category we use it 
 94              if len(filters)==1:  
 95                  return filters.values()[0] 
 96              else: #ambiguity 
 97                  raise ValueError('FilterManager: Multiple filters detected for %s category: %s, '\ 
 98                                   'but no one has be set as default in [GPIComponentFilters] section of the configuration file'  
 99                                   % (category,str(filters.keys()))) 
100          except KeyError: 
101              #wrong filter name in configuration for this category 
102              raise ValueError('FilterManager: %s filter is not registered for %s category.'\ 
103                               'Check your [GPIComponentFilters] section of the configuration file'  
104                               % (filtername,category)) 
105           
106   
107  # all filters register here... 
108  allComponentFilters = _ComponentFilterManager() 
109