00001 #!/usr/local/bin/python
00002 #
00003 # Copyright 2006
00004 # by
00005 # The Board of Trustees of the
00006 # Leland Stanford Junior University.
00007 # All rights reserved.
00008 #
00009
00010 __facility__ = "Online"
00011 __abstract__ = "Read LDF event contributions from a file"
00012 __author__ = "R. Claus <Claus@SLAC.Stanford.edu> SLAC - GLAST LAT I&T/Online"
00013 __date__ = "3/30/2006"
00014 __updated__ = ("$Date: 2006/07/19 16:08:50 $").split(' ')[1]
00015 __version__ = "$Revision: 1.2 $"
00016 __release__ = "$Name: R04-12-00 $"
00017 __credits__ = "SLAC"
00018
00019 import LATTE.copyright_SLAC
00020
00021 import struct
00022 import logging as log
00023 import LDF
00024
00025 import LATTE.merger.geb as geb
00026 from LATTE.merger.ldfContribution import LdfContribution
00027
00028
00029 class LdfContributor(geb.GebContributor):
00030 def __init__(self, filename, offset = 1):
00031 geb.GebContributor.__init__(self)
00032 self.__filename = filename
00033 self.__fakeEvent = struct.pack(">3L", LDF.EBFevent.ID, 3*4, 0xabadcafeL)
00034 self.__offset = offset
00035
00036 def name(self):
00037 return "LDF"
00038
00039 def offset(self):
00040 return self.__offset
00041
00042 def open(self):
00043 self.__file = file(self.__filename, 'rb')
00044 print "LdfContrib.open: %s opened" % (self.__filename)
00045
00046 def close(self):
00047 self.__file.close()
00048
00049 def read(self):
00050 """!\brief Method to read an LDF contribution from a file.
00051 """
00052 data = self.__file.read(8)
00053 if len(data) == 0: raise EOFError, "LdfContrib.read: End of file on %s" % (self.__filename)
00054 (typeId, length) = struct.unpack('>2L', data)
00055 if typeId != LDF.LATdatagram.ID:
00056 # Don't try to continue if bad typeId: we're lost or it's undefined
00057 raise KeyError, "ldfContrib.read: Unrecognized contribution %08x"%(typeId)
00058 #print "ldfContrib.read: id = %08x, len = %08x" % (typeId, length)
00059 data = self.__file.read(length - 8) # Only the LATcontribution(s) portion
00060
00061 status = 0
00062 return geb.Geb.Build, status, LdfContribution(self, data)
00063
00064 def fake(self):
00065 return self.__fakeEvent
00066
