Source code for background

#!/usr/bin/env python3

##########################################################################
# basf2 (Belle II Analysis Software Framework)                           #
# Author: The Belle II Collaboration                                     #
#                                                                        #
# See git log for contributors and copyright holders.                    #
# This file is licensed under LGPL-3.0, see LICENSE.md.                  #
##########################################################################

from basf2 import create_path, B2ERROR, B2INFO
from basf2.utils import pretty_print_table
import os
import glob


def get_background_files(folder=None, output_file_info=True):
    """ Loads the location of the background files from the environmant variable
    BELLE2_BACKGROUND_DIR which is set on the validation server and ensures that background
    files exist and returns the list of background files which
    can be directly used with add_simulation() :

    >>> add_simulation(main, bkgfiles=background.get_background_files())

    Will fail with an assert if no background folder set or if no background file was
    found in the set folder.

    Parameters:
        folder (str): A specific folder to search for background files can be given as an optional parameter
        output_file_info (str): If true, a list of the found background files and there size will be printed
                                This is useful to understand later which background campaign has been used
                                to simulate events.
    """

    env_name = 'BELLE2_BACKGROUND_DIR'
    bg = None

    if folder is None:
        if env_name not in os.environ:
            raise RuntimeError("Environment variable {} for backgound files not set. Terminanting this script.".format(env_name))
        folder = os.environ[env_name]

    bg = glob.glob(folder + '/*.root')

    if len(bg) == 0:
        raise RuntimeError("No background files found in folder {} . Terminating this script.".format(folder))

    B2INFO("Background files loaded from folder {}".format(folder))

    # sort for easier comparison
    bg = sorted(bg)

    if output_file_info:
        bg_sizes = [os.path.getsize(f) for f in bg]
        # reformat to work with pretty_print_table
        table_rows = [list(entry) for entry in zip(bg, bg_sizes)]
        table_rows.insert(0, ["- Background file name -", "- file size -"])

        pretty_print_table(table_rows, [0, 0])

    return bg


def add_output(path, bgType, realTime, sampleType, phase=3, fileName='output.root', excludeBranches=None):
    '''
    A function to be used for output of BG simulation.
    @param path path name
    @param bgType background type, to get available types: basf2 -m BeamBkgTagSetter
    @param realTime equivalent time of superKEKB running in [ns]
    @param sampleType 'study' (for BG studies) or 'usual', 'PXD', 'ECL' (for BG mixer)
    @param specify the Phase, 1 for Phase 1, 2 for Phase 2, and 3 for Physics Run or Phase 3
    @param fileName optional file name, can be overridden by basf2 -o
    '''
    if excludeBranches is None:
        excludeBranches = []

    if sampleType == 'study':
        madeFor = ''
        branches = []
    elif sampleType == 'usual' and phase == 3:
        madeFor = ''
        branches = [
            'PXDSimHits',
            'SVDSimHits',
            'CDCSimHits',
            'TOPSimHits',
            'ARICHSimHits',
            'ECLHits',
            'KLMSimHits',
        ]
    elif sampleType == 'usual' and phase == 2:
        madeFor = ''
        branches = [
            'PXDSimHits',
            'SVDSimHits',
            'CDCSimHits',
            'TOPSimHits',
            'ARICHSimHits',
            'ECLHits',
            'KLMSimHits',
            'CLAWSSimHits',
            'FANGSSimHits',
            'PlumeSimHits',
            'BeamabortSimHits',
            'PindiodeSimHits',
            'QcsmonitorSimHits',
            'He3tubeSimHits',
            'MicrotpcSimHits',
        ]
    elif sampleType == 'usual' and phase == 1:
        madeFor = ''
        branches = [
            'ClawSimHits',
            'BeamabortSimHits',
            'PindiodeSimHits',
            'QcsmonitorSimHits',
            'He3tubeSimHits',
            'MicrotpcSimHits',
            'BgoSimHits',
            'CsiSimHits',
        ]
    elif sampleType == 'ECL':
        madeFor = 'ECL'
        branches = ['ECLHits']
    elif sampleType == 'PXD':
        madeFor = 'PXD'
        branches = ['PXDSimHits']
    else:
        madeFor = ''
        branches = []
        B2ERROR('add_output - invalid value of argument sampleType: %s'
                % sampleType)

    # Set background tag in SimHits and add BackgroundMetaData into persistent tree
    tagSetter = path.add_module('BeamBkgTagSetter', backgroundType=bgType, realTime=realTime,
                                specialFor=madeFor, Phase=phase)

    # Write out only non-empty events when producing samples for BG mixer
    if sampleType != 'study':
        emptyPath = create_path()
        tagSetter.if_false(emptyPath)

    # Output to file. We don't need a TTreeIndex for background files and memory
    # consumption can be improved by setting a lower autoFlushSize so that
    # fewer and or smaller amounts of data have to be read for each GetEntry()
    path.add_module('RootOutput', outputFileName=fileName, branchNames=branches, excludeBranchNames=excludeBranches,
                    buildIndex=False, autoFlushSize=-500000)