GridFire v0.7.6rc4.0 General Purpose Nuclear Network

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Public Types | Public Member Functions | Public Attributes | Static Public Attributes | List of all members
gridfire::engine::scratch::GraphEngineScratchPad Struct Referencefinal

Scratchpad for storing CppAD automatic differentiation state for GraphEngine. More...

`#include <engine_graph_scratchpad.h>`

Inheritance diagram for gridfire::engine::scratch::GraphEngineScratchPad:
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Collaboration diagram for gridfire::engine::scratch::GraphEngineScratchPad:
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## Public Types
enum class | ADFunRegistrationResult : uint8_t { SUCCESS , ALREADY_REGISTERED }
| Result codes for ADFun registration operations. More...

## Public Member Functions
bool | is_initialized () const override
| Check whether the scratchpad has been initialized.
void | initialize (const GraphEngine &engine)
| Initialize the scratchpad from a GraphEngine.
std::unique_ptr< AbstractScratchPad > | clone () const override
| Create a deep copy of this scratchpad.
Public Member Functions inherited from gridfire::engine::scratch::AbstractScratchPad
virtual | ~AbstractScratchPad ()=default
| Virtual destructor for proper cleanup of derived classes.

## Public Attributes
std::optional< CppAD::ADFun< double > > | rhsADFun
| CppAD function object for evaluating the ODE right-hand side.
CppAD::sparse_jac_work | jac_work
| Work structure for sparse Jacobian calculations.
std::vector< double > | local_abundance_cache
| Local cache of abundance values for efficient RHS evaluation.
std::unordered_map< size_t, StepDerivatives< double > > | stepDerivativesCache
| Cache of step derivatives indexed by timestep identifier.
std::unordered_map< size_t, CppAD::sparse_rcv< std::vector< size_t >, std::vector< double > > > | jacobianSubsetCache
| Cache of sparse Jacobian subsets indexed by timestep identifier.
std::unordered_map< size_t, CppAD::sparse_jac_work > | jacWorkCache
| Cache of Jacobian work structures indexed by timestep identifier.
std::optional< StepDerivatives< double > > | most_recent_rhs_calculation
| The most recent RHS calculation result for warm-starting.
bool | has_initialized = false
| Flag indicating whether the scratchpad has been initialized.

## Static Public Attributes
static constexpr auto | ID = ScratchPadType::GRAPH_ENGINE_SCRATCHPAD
| Unique identifier for this scratchpad type.

## Detailed Description

Scratchpad for storing CppAD automatic differentiation state for GraphEngine.

GraphEngineScratchPad provides thread-local storage for all CppAD-related objects needed during ODE integration with the GraphEngine. This includes the ADFun object for evaluating the right-hand side of the ODE and computing Jacobians, as well as various caches to improve performance.

Thread Safety
  This class is not thread-safe. CppAD ADFun objects maintain internal state that is modified during Forward and Reverse mode operations. Each thread must have its own scratchpad instance. Use clone() to create independent copies for parallel execution.

Note
  When cloning, if the rhsADFun has not been initialized, the clone will also be uninitialized and has_initialized will be false.

## Member Enumeration Documentation

## ◆ ADFunRegistrationResult

enum class gridfire::engine::scratch::GraphEngineScratchPad::ADFunRegistrationResult : uint8_t
| strong

Result codes for ADFun registration operations.

Enumerator
SUCCESS | Registration completed successfully.
ALREADY_REGISTERED | ADFun was already registered; no action taken.

## Member Function Documentation

## ◆ clone()

std::unique_ptr< AbstractScratchPad > gridfire::engine::scratch::GraphEngineScratchPad::clone | ( |  | ) | const
| inline nodiscard override virtual

Create a deep copy of this scratchpad.

Creates an independent copy of all internal state, including the CppAD ADFun object and all caches. The clone can be safely used in a separate thread without affecting the original.

Returns
  A unique pointer to the cloned scratchpad.

Note
  If rhsADFun is not initialized, the clone will also be uninitialized (has_initialized = false).

Examples
  GraphEngineScratchPad scratch;
  scratch.initialize(engine);
  // Create independent copies for parallel workers
  std::vector<std::unique_ptr<AbstractScratchPad>> worker_pads;
  for (int i = 0; i < num_threads; ++i) {
  worker_pads.push_back(scratch.clone());
  }
  gridfire::engine::scratch
  Scratchpad memory management for computational engines.
  Definition blob.h:69
  gridfire::engine
  Definition dynamic_engine_diagnostics.h:39
  gridfire::engine::scratch::GraphEngineScratchPad
  Scratchpad for storing CppAD automatic differentiation state for GraphEngine.
  Definition engine_graph_scratchpad.h:83

Implements gridfire::engine::scratch::AbstractScratchPad.

## ◆ initialize()

void gridfire::engine::scratch::GraphEngineScratchPad::initialize | ( | const GraphEngine & | engine | ) |
| inline

Initialize the scratchpad from a GraphEngine.

Copies the authoritative ADFun from the engine and clears all caches. This method is idempotent; calling it multiple times has no effect after the first successful initialization.

Parameters

  engine | The GraphEngine to initialize from.

Examples
  GraphEngineScratchPad scratch;
  GraphEngine engine = create_engine();
  scratch.initialize(engine);
  // Now safe to use for thread-local computations
  auto& adfun = scratch.rhsADFun.value();
  gridfire::engine::GraphEngine
  A reaction network engine that uses a graph-based representation.
  Definition engine_graph.h:100

## ◆ is_initialized()

bool gridfire::engine::scratch::GraphEngineScratchPad::is_initialized | ( |  | ) | const
| inline nodiscard override virtual

Check whether the scratchpad has been initialized.

Returns
  true if initialized with a valid ADFun, false otherwise.

Implements gridfire::engine::scratch::AbstractScratchPad.

## Member Data Documentation

## ◆ has_initialized

bool gridfire::engine::scratch::GraphEngineScratchPad::has_initialized = false

Flag indicating whether the scratchpad has been initialized.

## ◆ ID

auto gridfire::engine::scratch::GraphEngineScratchPad::ID = ScratchPadType::GRAPH_ENGINE_SCRATCHPAD
| static constexpr

Unique identifier for this scratchpad type.

## ◆ jac_work

CppAD::sparse_jac_work gridfire::engine::scratch::GraphEngineScratchPad::jac_work

Work structure for sparse Jacobian calculations.

Reused across Jacobian evaluations to avoid reallocation.

## ◆ jacobianSubsetCache

std::unordered_map<size_t, CppAD::sparse_rcv<std::vector<size_t>, std::vector<double> > > gridfire::engine::scratch::GraphEngineScratchPad::jacobianSubsetCache

Cache of sparse Jacobian subsets indexed by timestep identifier.

## ◆ jacWorkCache

std::unordered_map<size_t, CppAD::sparse_jac_work> gridfire::engine::scratch::GraphEngineScratchPad::jacWorkCache

Cache of Jacobian work structures indexed by timestep identifier.

## ◆ local_abundance_cache

std::vector<double> gridfire::engine::scratch::GraphEngineScratchPad::local_abundance_cache

Local cache of abundance values for efficient RHS evaluation.

## ◆ most_recent_rhs_calculation

std::optional<StepDerivatives<double> > gridfire::engine::scratch::GraphEngineScratchPad::most_recent_rhs_calculation

The most recent RHS calculation result for warm-starting.

## ◆ rhsADFun

std::optional<CppAD::ADFun<double> > gridfire::engine::scratch::GraphEngineScratchPad::rhsADFun

CppAD function object for evaluating the ODE right-hand side.

Contains the computational graph for automatic differentiation.

## ◆ stepDerivativesCache

std::unordered_map<size_t, StepDerivatives<double> > gridfire::engine::scratch::GraphEngineScratchPad::stepDerivativesCache

Cache of step derivatives indexed by timestep identifier.

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

- src/include/gridfire/engine/scratchpads/engine_graph_scratchpad.h