Looper Class Reference

#include <looper.h>

Public Member Functions
	Looper (TChain *new_tchain)
	Looper (HEPCLI &cli)
virtual	~Looper ()
void	run (std::function< void(TTree *ttree)> init, std::function< void(int entry)> eval)
void	stop ()

Public Attributes
TChain *	tchain
TString	ttree_name
unsigned int	current_entry
unsigned int	n_events_processed
unsigned int	n_events_total

Protected Attributes
bool	keep_alive

Detailed Description

Object to handle looping over ROOT files

Constructor & Destructor Documentation

Looper() [1/2]

Looper::Looper

(

TChain *

new_tchain

)

Looper object constructor

Parameters

new_tchain

pointer to ROOT TChain of files to loop over

Returns

none

Looper() [2/2]

Looper::Looper

(

HEPCLI &

cli

)

Looper object constructor

Parameters

cli	HEPCLI object

Returns

none

~Looper()

virtual Looper::~Looper ( )

virtual

Looper object destructor

Returns

none

Member Function Documentation

run()

void Looper::run	(	std::function< void(TTree *ttree)>	init,
		std::function< void(int entry)>	eval )

Run looper with file- and event-processing logic captured in void lambda functions.

The following example uses a class named "Selector" generated by ROOT::MakeSelector; this class requires certain file- and event-processing initialization steps:

int main()
{
    TChain* tchain = new TChain("Events");
    tchain->Add("/path/to/file.root");
    selector = Selector(); // generated by ROOT::MakeSelector
    looper = Looper(tchain, "Events");
    looper.run(
        [&](TTree* ttree) { selector.Init(ttree); },
        [&](int entry) 
        {
            selector.GetEntry(entry);
            selector.Process(entry);
            // -> insert your favorite cutflow here <--
        }
    );
}

Parameters

init	file-level initialization steps captured in a void lambda function
eval	event-level logic captured in a void lambda function

Returns

none

stop()

void Looper::stop

(

)

Stop event loop

Returns

none

Member Data Documentation

current_entry

unsigned int Looper::current_entry

Current entry in TTree (i.e. current index of event loop)

keep_alive

bool Looper::keep_alive

protected

Flag for continuing event loop

n_events_processed

unsigned int Looper::n_events_processed

Number of events that have been processed

n_events_total

unsigned int Looper::n_events_total

Number of events in the TChain

tchain

TChain* Looper::tchain

ROOT TChain of files to loop over

ttree_name

TString Looper::ttree_name

ROOT TTree name

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The documentation for this class was generated from the following file:

• /github/workspace/rapido/src/looper.h