From 76f09c9fe1df737460d24f3f093ffd374d352d8d Mon Sep 17 00:00:00 2001
From: Walter Van Herck <w.van.herck@fz-juelich.de>
Date: Fri, 3 Feb 2017 18:12:52 +0100
Subject: [PATCH] Refactor: ScalarFresnelMap now maintains a cache (hash map)
of calculated Fresnel coefficients
---
Core/Computation/MainComputation.cpp | 2 +-
Core/Computation/MainComputation.h | 2 +-
Core/Multilayer/HashKVector.cpp | 22 +++++++++++++++++++
Core/Multilayer/HashKVector.h | 33 ++++++++++++++++++++++++++++
Core/Multilayer/ScalarFresnelMap.cpp | 17 +++++++++++---
Core/Multilayer/ScalarFresnelMap.h | 8 +++++--
6 files changed, 77 insertions(+), 7 deletions(-)
create mode 100644 Core/Multilayer/HashKVector.cpp
create mode 100644 Core/Multilayer/HashKVector.h
diff --git a/Core/Computation/MainComputation.cpp b/Core/Computation/MainComputation.cpp
index eb763f1954b..d657a339f96 100644
--- a/Core/Computation/MainComputation.cpp
+++ b/Core/Computation/MainComputation.cpp
@@ -92,7 +92,7 @@ void MainComputation::runProtected()
}
IFresnelMap* MainComputation::createFresnelMap(const MultiLayer* p_multilayer,
- const MultiLayer* p_inverted_multilayer)
+ const MultiLayer* p_inverted_multilayer)
{
if (!p_multilayer->requiresMatrixRTCoefficients())
return new ScalarFresnelMap(p_multilayer);
diff --git a/Core/Computation/MainComputation.h b/Core/Computation/MainComputation.h
index f7959257c38..1b60f584387 100644
--- a/Core/Computation/MainComputation.h
+++ b/Core/Computation/MainComputation.h
@@ -55,7 +55,7 @@ public:
private:
void runProtected();
static IFresnelMap* createFresnelMap(const MultiLayer* p_multilayer,
- const MultiLayer* p_inverted_multilayer);
+ const MultiLayer* p_inverted_multilayer);
std::unique_ptr<MultiLayer> mP_multi_layer;
std::unique_ptr<MultiLayer> mP_inverted_multilayer;
diff --git a/Core/Multilayer/HashKVector.cpp b/Core/Multilayer/HashKVector.cpp
new file mode 100644
index 00000000000..706690ba9cb
--- /dev/null
+++ b/Core/Multilayer/HashKVector.cpp
@@ -0,0 +1,22 @@
+// ************************************************************************** //
+//
+// BornAgain: simulate and fit scattering at grazing incidence
+//
+//! @file Core/Computation/HashKVector.cpp
+//! @brief Implements class HashKVector.
+//!
+//! @homepage http://www.bornagainproject.org
+//! @license GNU General Public License v3 or higher (see COPYING)
+//! @copyright Forschungszentrum Jülich GmbH 2017
+//! @authors Scientific Computing Group at MLZ Garching
+//! @authors J. Burle, J. M. Fisher, M. Ganeva, G. Pospelov, W. Van Herck, J. Wuttke
+//
+// ************************************************************************** //
+
+#include "HashKVector.h"
+
+// Simple exclusive or of the std::hash<double> of its components
+size_t HashKVector::operator()(kvector_t kvec) const noexcept
+{
+ return m_double_hash(kvec.x()) ^ m_double_hash(kvec.y()) ^ m_double_hash(kvec.z());
+}
diff --git a/Core/Multilayer/HashKVector.h b/Core/Multilayer/HashKVector.h
new file mode 100644
index 00000000000..5e76a968fb1
--- /dev/null
+++ b/Core/Multilayer/HashKVector.h
@@ -0,0 +1,33 @@
+// ************************************************************************** //
+//
+// BornAgain: simulate and fit scattering at grazing incidence
+//
+//! @file Core/Computation/HashKVector.h
+//! @brief Defines class HashKVector.
+//!
+//! @homepage http://www.bornagainproject.org
+//! @license GNU General Public License v3 or higher (see COPYING)
+//! @copyright Forschungszentrum Jülich GmbH 2017
+//! @authors Scientific Computing Group at MLZ Garching
+//! @authors J. Burle, J. M. Fisher, M. Ganeva, G. Pospelov, W. Van Herck, J. Wuttke
+//
+// ************************************************************************** //
+
+#ifndef HASHKVECTOR_H
+#define HASHKVECTOR_H
+
+#include "Vectors3D.h"
+#include <functional>
+
+class HashKVector
+{
+public:
+ HashKVector() {}
+ ~HashKVector() {}
+
+ size_t operator()(kvector_t kvec) const noexcept;
+private:
+ std::hash<double> m_double_hash;
+};
+
+#endif // HASHKVECTOR_H
diff --git a/Core/Multilayer/ScalarFresnelMap.cpp b/Core/Multilayer/ScalarFresnelMap.cpp
index 8d4c3fcc2d8..8edb9ba0830 100644
--- a/Core/Multilayer/ScalarFresnelMap.cpp
+++ b/Core/Multilayer/ScalarFresnelMap.cpp
@@ -23,6 +23,9 @@ ScalarFresnelMap::ScalarFresnelMap(const MultiLayer* multilayer)
: mp_multilayer(multilayer)
{}
+ScalarFresnelMap::~ScalarFresnelMap()
+{}
+
const ILayerRTCoefficients* ScalarFresnelMap::getOutCoefficients(
const SimulationElement& sim_element, size_t layer_index) const
{
@@ -38,7 +41,15 @@ const ILayerRTCoefficients* ScalarFresnelMap::getInCoefficients(
const ScalarRTCoefficients* ScalarFresnelMap::getCoefficients(
kvector_t kvec, size_t layer_index) const
{
- SpecularMatrix::MultiLayerCoeff_t coeffs;
- SpecularMatrix::execute(*mp_multilayer, kvec, coeffs);
- return new ScalarRTCoefficients(coeffs[layer_index]);
+ ScalarRTCoefficients* result;
+ auto it = m_hash_table.find(kvec);
+ if (it != m_hash_table.end())
+ result = new ScalarRTCoefficients(it->second[layer_index]);
+ else {
+ std::vector<ScalarRTCoefficients> coeffs;
+ SpecularMatrix::execute(*mp_multilayer, kvec, coeffs);
+ result = new ScalarRTCoefficients(coeffs[layer_index]);
+ m_hash_table[kvec] = std::move(coeffs);
+ }
+ return result;
}
diff --git a/Core/Multilayer/ScalarFresnelMap.h b/Core/Multilayer/ScalarFresnelMap.h
index 1a021daf3f3..fd3b7e1e290 100644
--- a/Core/Multilayer/ScalarFresnelMap.h
+++ b/Core/Multilayer/ScalarFresnelMap.h
@@ -16,8 +16,10 @@
#ifndef SCALARFRESNELMAP_H
#define SCALARFRESNELMAP_H
+#include "HashKVector.h"
#include "IFresnelMap.h"
-#include "Vectors3D.h"
+#include <unordered_map>
+#include <vector>
class MultiLayer;
class ILayerRTCoefficients;
@@ -31,7 +33,7 @@ class BA_CORE_API_ ScalarFresnelMap : public IFresnelMap
{
public:
ScalarFresnelMap(const MultiLayer* multilayer);
- ~ScalarFresnelMap() final {}
+ ~ScalarFresnelMap() final;
//! Retrieves the amplitude coefficients for the given angles
const ILayerRTCoefficients* getOutCoefficients (
@@ -44,6 +46,8 @@ public:
private:
const MultiLayer* mp_multilayer;
const ScalarRTCoefficients* getCoefficients(kvector_t kvec, size_t layer_index) const;
+ mutable std::unordered_map<kvector_t, std::vector<ScalarRTCoefficients>,
+ HashKVector> m_hash_table;
};
#endif // SCALARFRESNELMAP_H
--
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