Source Code for Module asmach.user_data

  1   
  2  import threading 
  3  import copy 
  4   
  5  import asmach as smach 
  6   
  7  __all__ = ['UserData','Remapper'] 
  8   
  9 -class UserData(object): 
 10      """SMACH user data structure.""" 
 11 -    def __init__(self): 
 12          self._data = {} 
 13          self._locks = {} 
 14          self.__initialized = True 
 15   
 16 -    def update(self, other_userdata): 
 17          """Combine this userdata struct with another. 
 18          This overwrites duplicate keys with values from C{other_userdata}. 
 19          """ 
 20          # Merge data 
 21          self._data.update(other_userdata._data) 
 22   
 23 -    def extract(self, keys, remapping): 
 24          ud = UserData() 
 25          reverse_remapping = dict([(v,k) for (k,v) in remapping.iteritems()]) 
 26          if len(reverse_remapping) != len(remapping): 
 27              smach.logerr("SMACH userdata remapping is not one-to-one: " + str(remapping)) 
 28          for k in keys: 
 29              rmk = k 
 30              if k in reverse_remapping: 
 31                  rmk = reverse_remapping[k] 
 32              ud[rmk] = copy.copy(self[k]) 
 33          return ud 
 34   
 35 -    def merge(self, ud, keys, remapping): 
 36          for k in keys: 
 37              rmk = k 
 38              if k in remapping: 
 39                  rmk = remapping[k] 
 40              self[rmk] = copy.copy(ud[k]) 
 41   
 42 -    def __getitem__(self, key): 
 43          return self.__getattr__(key) 
 44   
 45 -    def __setitem__(self, key, item): 
 46          self._data[key] = item 
 47   
 48 -    def keys(self): 
 49          return self._data.keys() 
 50   
 51 -    def __contains__(self,key): 
 52          return key in self._data 
 53   
 54 -    def __getattr__(self, name): 
 55          """Overload getattr to be thread safe.""" 
 56          if name[0] == '_': 
 57              return object.__getattr__(self, name) 
 58          if not name in self._locks.keys(): 
 59              self._locks[name] = threading.Lock() 
 60   
 61          try: 
 62              with self._locks[name]: 
 63                  temp = self._data[name] 
 64          except: 
 65              smach.logerr("Userdata key '%s' not available. Available keys are: %s" % (name, self._data.keys())) 
 66              raise KeyError() 
 67   
 68          return temp 
 69   
 70 -    def __setattr__(self, name, value): 
 71          """Overload setattr to be thread safe.""" 
 72          # If we're still in __init__ don't do anything special 
 73          if name[0] == '_' or not self.__dict__.has_key('_UserData__initialized'): 
 74              return object.__setattr__(self, name, value) 
 75   
 76          if not name in self._locks.keys(): 
 77              self._locks[name] = threading.Lock() 
 78   
 79          self._locks[name].acquire() 
 80          self._data[name] = value 
 81          self._locks[name].release() 
 82   
 83  # Const wrapper 
 84 -def get_const(obj): 
 85      """Get a const reference to an object if it has "user-defined" attributes.""" 
 86      if hasattr(obj,'__dict__'): 
 87          smach.logdebug("Making const '%s'" % str(obj)) 
 88          return Const(obj) 
 89      else: 
 90          return obj 
 91   
 92 -class Const(object): 
 93      """Wrapper that treats "user-defined" fields as immutable. 
 94       
 95      This wrapper class is used when user data keys are specified as input keys, 
 96      but not as output keys. 
 97      """ 
 98 -    def __init__(self, obj): 
 99          smach.logdebug("Making const '%s'" % str(obj)) 
100          self._obj = obj 
101          self.__initialized = True 
102   
103 -    def __getattr__(self, name): 
104          smach.logdebug("Getting '%s' from const wrapper." % name) 
105          attr = getattr(self._obj,name) 
106          return get_const(attr) 
107   
108 -    def __getitem__(self, name): 
109          smach.logdebug("Getting '%s' from const wrapper." % name) 
110          attr = self._obj[name] 
111          return get_const(attr) 
112   
113 -    def __setattr__(self, name, value): 
114          if not self.__dict__.has_key('_const__initialized'):  
115              return object.__setattr__(self, name, value) 
116          smach.logerr("Attempting to set '%s' but this member is read-only." % name) 
117          raise TypeError() 
118   
119 -    def __delattr__(self, name): 
120          smach.logerr("Attempting to delete '%s' but this member is read-only." % name) 
121          raise TypeError() 
122   
123 -class Remapper(UserData): 
124      """Key-remapping proxy to a SMACH userdata structure.""" 
125 -    def __init__(self, ud, input_keys=[], output_keys=[], remapping={}): 
126          self._ud = ud 
127          self._input = input_keys 
128          self._output = output_keys 
129          self._map =  remapping 
130          self.__initialized = True 
131   
132 -    def _remap(self, key): 
133          """Return either the key or it's remapped value.""" 
134          if key in self._map: 
135              return self._map[key] 
136          return key 
137   
138 -    def update(self, other_userdata): 
139          self._ud.updatea(other_userdata) 
140   
141 -    def __getitem__(self, key): 
142          if key not in self._input: 
143              raise smach.InvalidUserCodeError("Reading from SMACH userdata key '%s' but the only keys that were declared as input to this state were: %s. This key needs to be declaread as input to this state. " % (key, self._input)) 
144          if key not in self._output: 
145              return get_const(self._ud.__getitem__(self._remap(key))) 
146          return self._ud.__getitem__(self._remap(key)) 
147   
148 -    def __setitem__(self, key, item): 
149          if key not in self._output: 
150              smach.logerr("Writing to SMACH userdata key '%s' but the only keys that were declared as output from this state were: %s." % (key, self._output)) 
151              return 
152          self._ud.__setitem__(self._remap(key),item) 
153   
154 -    def keys(self): 
155          return [self._remap(key) for key in self._ud.keys() if key in self._input] 
156   
157 -    def __contains__(self,key): 
158          if key in self._input: 
159              return self._remap(key) in self._ud 
160          else: 
161              return False 
162   
163 -    def __getattr__(self, name): 
164          if name[0] == '_': 
165              return object.__getattr__(self, name) 
166          if name not in self._input: 
167              raise smach.InvalidUserCodeError("Reading from SMACH userdata key '%s' but the only keys that were declared as input to this state were: %s. This key needs to be declaread as input to this state. " % (name, self._input)) 
168          if name not in self._output: 
169              return get_const(getattr(self._ud, self._remap(name))) 
170          return getattr(self._ud, self._remap(name)) 
171   
172 -    def __setattr__(self, name, value): 
173          if name[0] == '_' or not self.__dict__.has_key('_Remapper__initialized'): 
174              return object.__setattr__(self, name, value) 
175          if name not in self._output: 
176              smach.logerr("Writing to SMACH userdata key '%s' but the only keys that were declared as output from this state were: %s." % (name, self._output)) 
177              return None 
178          setattr(self._ud, self._remap(name), value) 
179