Source code for otestpoint.labtools.variable

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from subject import Subject
import traceback
import numpy as np

[docs]class Variable(Subject): def __init__(self,stream,measurement,attribute,**kwargs): """Creates a Variable instance that will receive attribute measurement updates. You must be sure to instantiate the Stream with a probe that provides the specified measurement in order to receive updates. Args: measurement (str): Name of the measurement to associate with the variable. attribute (str): Name of the attribute contained in the measurment to associate with the variable. Keyword Args: apply (callable): Callable applied to a measurment prior to storing. Useful to reduce storage to just the relevant measurement information of interest. Default: lambda x: x. cache (int): Number of measurments to cache per reporting tag. Default: Value set for stream. tags ([str]): Names of tags to include measurments from. If empty all tags are included. Default: []. Raises: KeyError: If an invalid keyword is found. """ Subject.__init__(self,stream) self._measurement = measurement self._attribute = attribute self._cache = kwargs.pop('cache',5) self._tags = set(kwargs.pop('tags',[])) self._apply = kwargs.pop('apply',lambda x: x) self._store = {} self._updates = set() if kwargs: raise KeyError("Unknown key(s): %s" % ", ".join(kwargs.keys()))
[docs] def name(self): """Gets the variable name Returns: str: Variable name. """ if self._tags: tags = '::[%s]' % ','.join(self._tags) else: tags = '' return '%s::%s%s' % (self._measurement,self._attribute,tags)
def update(self,timestamp,tag,msg): if not self._tags or tag in self._tags: if timestamp not in self._store: if len(self._store) == self._cache: self._store.pop(sorted(self._store.keys())[0]) self._store[timestamp] = {tag:np.nan for tag in self._tags} try: self._store[timestamp][tag] = self._apply(getattr(msg,self._attribute)) self._updates.add(timestamp) return True except Exception as exp: traceback.print_exc() return False def notify(self): self.notify_observers() self._updates = set() def state(self): return self._store,self._updates def reset(self): self._store.clear() self._updates.clear() self.notify_observers()