Cantera  2.4.0
Public Member Functions | Protected Attributes | Static Protected Attributes | List of all members
ValueCache Class Reference

#include <ValueCache.h>

Public Member Functions

int getId ()
 Get a unique id for a cached value. More...
 
CachedScalar getScalar (int id)
 Get a reference to a CachedValue object representing a scalar (doublereal) with the given id. More...
 
CachedArray getArray (int id)
 Get a reference to a CachedValue object representing an array (vector_fp) with the given id. More...
 
void clear ()
 Clear all cached values. More...
 

Protected Attributes

std::map< int, CachedValue< double > > m_scalarCache
 Cached scalar values. More...
 
std::map< int, CachedValue< vector_fp > > m_arrayCache
 Cached array values. More...
 

Static Protected Attributes

static int m_last_id = 0
 The last assigned id. Automatically incremented by the getId() method. More...
 

Detailed Description

Storage for cached values

Stores cached values of properties evaluated at a particular thermodynamic state. A class that needs cached values can have a ValueCache as a member variable.

Each method in the class that implements caching behavior needs a unique id for its cached value. This id should be obtained by using the getId() function to initialize a static variable within the function.

For cases where the property is a scalar or vector, the cached value can be stored in the CachedValue object. If the data type of the cached value is more complex, then it can be stored in the calling class, and the value attribute of the CachedScalar object can be ignored.

An example use of class ValueCache:

class Example {
ValueCache m_cache;
doublereal get_property(doublereal T, doublereal P) {
const static int cacheId = m_cache.getId();
CachedScalar cached = m_cache.getScalar(cacheId);
if (T != cached.state1 || P != cached.state2) {
cached.value = some_expensive_function(T,P);
cached.state1 = T;
cached.state2 = P;
}
return cached.value;
}
};

Definition at line 156 of file ValueCache.h.

Member Function Documentation

◆ getId()

int getId ( )

◆ getScalar()

CachedScalar getScalar ( int  id)
inline

◆ getArray()

CachedArray getArray ( int  id)
inline

Get a reference to a CachedValue object representing an array (vector_fp) with the given id.

Definition at line 171 of file ValueCache.h.

References ValueCache::m_arrayCache.

Referenced by MaskellSolidSolnPhase::getActivityCoefficients().

◆ clear()

void clear ( )

Clear all cached values.

This method should be called if the cached values may be invalidated in a way that is not represented by the state variables alone, such as a change to the constants defining a species thermodynamics as a function of temperature.

Definition at line 27 of file ValueCache.cpp.

References ValueCache::m_arrayCache, and ValueCache::m_scalarCache.

Referenced by Phase::invalidateCache().

Member Data Documentation

◆ m_scalarCache

std::map<int, CachedValue<double> > m_scalarCache
protected

Cached scalar values.

Definition at line 183 of file ValueCache.h.

Referenced by ValueCache::clear(), and ValueCache::getScalar().

◆ m_arrayCache

std::map<int, CachedValue<vector_fp> > m_arrayCache
protected

Cached array values.

Definition at line 186 of file ValueCache.h.

Referenced by ValueCache::clear(), and ValueCache::getArray().

◆ m_last_id

int m_last_id = 0
staticprotected

The last assigned id. Automatically incremented by the getId() method.

Definition at line 189 of file ValueCache.h.

Referenced by ValueCache::getId().


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