gridfire::QSECacheKey Struct Reference

Key struct for the QSE abundance cache. More...

#include <engine_multiscale.h>

Public Member Functions
	QSECacheKey (const double T9, const double rho, const std::vector< double > &Y)
	Constructs a QSECacheKey.
size_t	hash () const
	Computes the hash value for this key.
bool	operator== (const QSECacheKey &other) const
	Equality operator for QSECacheKey.

Static Public Member Functions
static long	bin (double value, double tol)
	Converts a value to a discrete bin based on a tolerance.

Public Attributes
double	m_T9
double	m_rho
std::vector< double >	m_Y
	Note that the ordering of Y must match the dynamic species indices in the view.
std::size_t	m_hash = 0
	Precomputed hash value for this key.
QSECacheConfig	m_cacheConfig

Detailed Description

Key struct for the QSE abundance cache.

Purpose

This struct is used as the key for the QSE abundance cache (m_qse_abundance_cache) within the MultiscalePartitioningEngineView. Its primary goal is to avoid expensive re-partitioning and QSE solves for thermodynamic conditions that are "close enough" to previously computed ones.

How

It works by storing the temperature (m_T9), density (m_rho), and species abundances (m_Y). A pre-computed hash is generated in the constructor by calling the hash() method. This method discretizes the continuous physical values into bins using the tolerances defined in QSECacheConfig. The operator== simply compares the pre-computed hash values for fast lookups in the std::unordered_map.

Constructor & Destructor Documentation

QSECacheKey()

gridfire::QSECacheKey::QSECacheKey	(	const double	T9,
		const double	rho,
		const std::vector< double > &	Y )

Constructs a QSECacheKey.

Parameters

T9	Temperature in units of 10^9 K.
rho	Density in g/cm^3.
Y	Species molar abundances.

Postcondition

The m_hash member is computed and stored.

Member Function Documentation

bin()

long gridfire::QSECacheKey::bin ( double value, double tol )

static

Converts a value to a discrete bin based on a tolerance.

Parameters

value	The value to bin.
tol	The tolerance (bin width) to use for binning.

Returns

The bin number as a long integer.

How

The algorithm is floor(value / tol).

hash()

size_t gridfire::QSECacheKey::hash

(

)

const

Computes the hash value for this key.

Returns

The computed hash value.

How

This method combines the hashes of the binned temperature, density, and each species abundance. The bin() static method is used for discretization.

operator==()

bool gridfire::QSECacheKey::operator==

(

const QSECacheKey &

other

)

const

Equality operator for QSECacheKey.

Parameters

other

The other QSECacheKey to compare to.

Returns

True if the pre-computed hashes are equal, false otherwise.

Member Data Documentation

m_cacheConfig

QSECacheConfig gridfire::QSECacheKey::m_cacheConfig

Initial value:

= {
            1e-3, 
            1e-1, 
            1e-3  
        }

m_hash

std::size_t gridfire::QSECacheKey::m_hash = 0

Precomputed hash value for this key.

m_rho

double gridfire::QSECacheKey::m_rho

m_T9

double gridfire::QSECacheKey::m_T9

m_Y

std::vector<double> gridfire::QSECacheKey::m_Y

Note that the ordering of Y must match the dynamic species indices in the view.

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

• src/include/gridfire/engine/views/engine_multiscale.h
• src/lib/engine/views/engine_multiscale.cpp