fire::io::ParameterStorage Class Reference

Provides dynamic parameter storage by interfacing between a map to variants storing parameters and a h5::Data secialization. More...

#include <ParameterStorage.h>

Public Member Functions
template<typename ParameterType >
const ParameterType &	get (const std::string &name) const
	Get a parameter corresponding to the input name. More...
template<typename ParameterType >
void	set (const std::string &name, const ParameterType &val)
	Set a parameter to be a specific value. More...
void	clear ()
	clear the parameters More...

Private Attributes
std::unordered_map< std::string, std::variant< int, float, std::string > >	parameters_
	three types of parameters are allowed: int, float, string

Friends
class	Data< ParameterStorage >
	allow data set access for reading/writing

Detailed Description

Provides dynamic parameter storage by interfacing between a map to variants storing parameters and a h5::Data secialization.

This class does some pretty absurd nonsense in order to be able to store a dynamic set of parameters of various types. The type casting necessary to load and save the data stored within this object does negatively impact performance, so this class should be used sparingly. Moreover, the h5::Data<ParameterStorage>::load mechanic only reads in new parameters into the map from disk on the first load call (it continues to load values). This prevents ParameterStorage from being usable by normal event objects whose data set names may change between input files due to changing pass names.

Currently, it is only used within the fire::EventHeader and the fire::RunHeader and users of fire are discouraged from using it within their own classes.

ParameterStorage only supports three atomic types (int, float, and std::string). This is just to keep the code relatively simple.

Member Function Documentation

clear()

void fire::io::ParameterStorage::clear

(

)

clear the parameters

We don't clear the container of parameters, we clear them individually by setting them to the numeric_limits minimum or clearing the std::string.

This is to help minimize the save/load type deduction processes that are necessary within h5::Data<ParameterStorage>.

get()

template<typename ParameterType >

const ParameterType & fire::io::ParameterStorage::get ( const std::string &  name ) const

inline

Get a parameter corresponding to the input name.

Exceptions

Exception	if requested type differs from the type stored
Exception	if parameter is not found

usage

It is recomended to use auto to avoid code repitition.

// ps is a ParameterStorage instance that already has "one" in it.
auto one = ps.get<float>("one");

Template Parameters

ParameterType

type of parameter that is being requested

Parameters

[in]

name

name of parameter to get

Returns

const reference to parameter named name

set()

template<typename ParameterType >

void fire::io::ParameterStorage::set ( const std::string &  name, const ParameterType &  val  )

inline

Set a parameter to be a specific value.

Note

We do not check if another parameter is being overwritten.

usage

With C++17's argument type deduction feature, the template parameter can be left out.

ParameterStorage ps;
// these two are the same
ps.set("one",1.0);
ps.set<float>("one",1.0);
// this will not compile because double's aren't supported
ps.set<double>("one",1.0);

Template Parameters

The	type of the parameter that is being set.

Parameters

[in]	name	Name of the parameter to set
[in]	val	value of the parameter to keep in storage

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

• include/fire/io/ParameterStorage.h
• src/fire/io/ParameterStorage.cxx