Retriever.py

#!/usr/local/bin/python
#
#                               Copyright 2004
#                                     by
#                        The Board of Trustees of the
#                     Leland Stanford Junior University.
#                            All rights reserved.
#

__facility__ = "Online"
__abstract__ = "Housekeeping retriever module"
__author__   = "J. Panetta <panetta@SLAC.Stanford.edu> SLAC - GLAST LAT I&T/Online"
__date__     = "7/20/2004"
__version__  = "$Revision: 1.3 $"
__credits__  = "SLAC"


import LATTE.copyright_SLAC

from LATTE.monitoring.Trendable import Trendable

class Retriever(object):
  def __init__(self):
    pass
  def startup(self):
    pass
  def shutdown(self):
    pass
  def retrievePacket(self):
    raise NotImplementedError('retrievePacket()'\
                              +'must be implemented in a subclass.')

class DummyRetriever(Retriever):
  """ Dummy retriever used for testing.

  Creates 24 trendable objects which are simply sin/cos functions.
  """
  def __init__(self):
    self.monitorList={}
    for i in range(12):
      self.monitorList['cos_'+'%02i'%(i,)]={'lofail':-0.9,'lowarn':-0.7,
                                            'hiwarn':0.7,'hifail':0.9}
      self.monitorList['sin_'+'%02i'%(i,)]={'lofail':-0.9,'lowarn':-0.7,
                                            'hiwarn':0.7,'hifail':0.9}

  def retrievePacket(self):
    import math, time
    t=time.time()  # time() returns seconds since epoch, UTC
    data=[]
    keys=self.monitorList.keys()
    keys.sort()
    for k in keys:
      if k.startswith('sin'):
        v=math.sin(t*math.pi/12)
      elif k.startswith('cos'):
        v=math.cos(t*math.pi/12)
      # print "appending Trendable ", k
      data.append(Trendable(k,t,{'Raw Value':v}))
    return data

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