AthenaPoolExample_Read.py

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#!/env/python
 
# Copyright (C) 2002-2024 CERN for the benefit of the ATLAS collaboration
 

 
from AthenaConfiguration.AllConfigFlags import initConfigFlags
from AthenaConfiguration.ComponentFactory import CompFactory
from AthenaCommon.Constants import DEBUG
 
# Setup flags
flags = initConfigFlags()
flags.Input.Files = [ "EmptyPoolFile.root", "SimplePoolFile1.root", 
                      "EmptyPoolFile.root", "SimplePoolFile2.root", "SimplePoolFile3.root"]
flags.Exec.MaxEvents = -1
flags.Common.MsgSuppression = False
flags.Exec.DebugMessageComponents = [ "ReadData", "PoolSvc", "AthenaPoolCnvSvc",
                                      "AthenaPoolAddressProviderSvc", "MetaDataSvc", "EventSelector" ]
flags.lock()
 
# Main services
from AthenaConfiguration.MainServicesConfig import MainServicesCfg
acc = MainServicesCfg( flags )
 
# Configure AthenaPool reading
from AthenaPoolExampleAlgorithms.AthenaPoolExampleConfig import AthenaPoolExampleReadCfg
acc.merge( AthenaPoolExampleReadCfg(flags, readCatalogs = ["file:Catalog1.xml"]) )
 
# Create and attach the reading algorithm 
acc.addEventAlgo( CompFactory.AthPoolEx.ReadData("ReadData", OutputLevel = DEBUG) )
 
evSelector = acc.getService("EventSelector")
evSelector.SkipEvents = 8 # // skip the first 8 events
evSelector.SkipEventSequence = [ 9, 10 ] # // skip two more events
#evSelector.SkipEventSequence = " 4-6,7 , 8 , 9 - 10 "; # // skip seven more events
#evSelector.ProcessEventSequence = "11, 12, 13,14,15, 16-20, 21 - 25 , 26- 100"; # // skip two more events
 
#Switch Off for TAG - start
poolAttribs = acc.getService("AthenaPoolCnvSvc").InputPoolAttributes
# Turn on the tree cache for the CollectionTree - tree cache only works for one tree.
# Set number of events for learning before turning on cache - default is 5
poolAttribs += [ "DatabaseName = '*'; TREE_CACHE_LEARN_EVENTS = '6'" ]
# And set tree cache size - default is 10 MB (10 000 000)
poolAttribs += [ "DatabaseName = '*'; ContainerName = 'CollectionTree'; TREE_CACHE = '100000'" ]
 
# Print out values - must have PoolSvc in info mode
poolAttribs += [ "DatabaseName = '*'; TREE_CACHE_LEARN_EVENTS = 'int'" ]
poolAttribs += [ "DatabaseName = '*'; TREE_CACHE_SIZE = 'int'" ]
 
# Print out for each event the number of bytes read and the number of
# read calls. With the tree cache, one should see jumps in the bytes
# read by the cache size, i.e. the bytes read should not change each
# event. However, the cache only works on one tree - the main event
# tree (CollectionTree) - and we read some things from other trees, so
# one does see a small increase event-by-event.
printOpts = acc.getService("AthenaPoolCnvSvc").PrintInputAttrPerEvt
printOpts += [ "DatabaseName = '*'; BYTES_READ = 'double'" ]
printOpts += [ "DatabaseName = '*'; READ_CALLS = 'int'" ]
#Switch Off for TAG - end
 
# Run
import sys
sc = acc.run(flags.Exec.MaxEvents)
sys.exit(sc.isFailure())