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field_typed.hh
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/**
* file field_typed.hh
*
* @author Till Junge <till.junge@epfl.ch>
*
* @date 10 Apr 2018
*
* @brief Typed Field for dynamically sized fields and base class for fields
* of tensors, matrices, etc
*
* @section LICENSE
*
* Copyright © 2018 Till Junge
*
* µSpectre is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, either version 3, or (at
* your option) any later version.
*
* µSpectre is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU Emacs; see the file COPYING. If not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifndef FIELD_TYPED_H
#define FIELD_TYPED_H
#include "field_base.hh"
#include <sstream>
namespace muSpectre {
/**
* Dummy intermediate class to provide a run-time polymorphic
* typed field. Mainly for binding Python. TypedField specifies methods
* that return typed Eigen maps and vectors in addition to pointers to the
* raw data.
*/
template <class FieldCollection, typename T>
class TypedField: public internal::FieldBase<FieldCollection>
{
public:
using Parent = internal::FieldBase<FieldCollection>; //!< base class
//! for type checks when mapping this field
using collection_t = typename Parent::collection_t;
using Scalar = T; //!< for type checks
using Base = Parent; //!< for uniformity of interface
//! Plain Eigen type to map
using EigenRep_t = Eigen::Array<T, Eigen::Dynamic, Eigen::Dynamic>;
//! map returned when iterating over field
using EigenMap_t = Eigen::Map<EigenRep_t>;
//! Plain eigen vector to map
using EigenVec_t = Eigen::Map<Eigen::VectorXd>;
//! vector map returned when iterating over field
using EigenVecConst_t = Eigen::Map<const Eigen::VectorXd>;
/**
* type stored (unfortunately, we can't statically size the second
* dimension due to an Eigen bug,i.e., creating a row vector
* reference to a column vector does not raise an error :(
*/
using Stored_t = Eigen::Array<T, Eigen::Dynamic, Eigen::Dynamic>;
//! storage container
using Storage_t = std::vector<T,Eigen::aligned_allocator<T>>;
//! Default constructor
TypedField() = delete;
//! constructor
TypedField(std::string unique_name,
FieldCollection& collection,
size_t nb_components);
/**
* constructor for field proxies which piggy-back on existing
* memory. These cannot be registered in field collections and
* should only be used for transient temporaries
*/
TypedField(std::string unique_name,
FieldCollection& collection,
Eigen::Ref<Eigen::Matrix<Real, Eigen::Dynamic, 1>> vec,
size_t nb_components);
//! Copy constructor
TypedField(const TypedField &other) = delete;
//! Move constructor
TypedField(TypedField &&other) = default;
//! Destructor
virtual ~TypedField() = default;
//! Copy assignment operator
TypedField& operator=(const TypedField &other) = delete;
//! Move assignment operator
TypedField& operator=(TypedField &&other) = delete;
//! return type_id of stored type
virtual const std::type_info & get_stored_typeid() const override final;
virtual size_t size() const override final;
//! add a pad region to the end of the field buffer; required for
//! using this as e.g. an FFT workspace
void set_pad_size(size_t pad_size_) override final;
//! initialise field to zero (do more complicated initialisations through
//! fully typed maps)
virtual void set_zero() override final;
//! add a new value at the end of the field
inline void push_back(const Stored_t & value);
//! raw pointer to content (e.g., for Eigen maps)
virtual T* data() {return this->get_ptr_to_entry(0);}
//! raw pointer to content (e.g., for Eigen maps)
virtual const T* data() const {return this->get_ptr_to_entry(0);}
//! return a map representing the entire field as a single `Eigen::Array`
EigenMap_t eigen();
//! return a map representing the entire field as a single Eigen vector
EigenVec_t eigenvec();
//! return a map representing the entire field as a single Eigen vector
EigenVecConst_t eigenvec() const;
//! return a map representing the entire field as a single Eigen vector
EigenVecConst_t const_eigenvec() const;
protected:
//! returns a raw pointer to the entry, for `Eigen::Map`
inline T* get_ptr_to_entry(const size_t&& index);
//! returns a raw pointer to the entry, for `Eigen::Map`
inline const T*
get_ptr_to_entry(const size_t&& index) const;
//! set the storage size of this field
inline virtual void resize(size_t size) override final;
//! The actual storage container
Storage_t values{};
/**
* an unregistered typed field can be mapped onto an array of
* existing values
*/
optional<Eigen::Ref<Eigen::Matrix<Real, Eigen::Dynamic, 1>>> alt_values{};
/**
* maintains a tally of the current size, as it cannot be reliably
* determined from either `values` or `alt_values` alone.
*/
size_t current_size;
/**
* in order to accomodate both registered fields (who own and
* manage their data) and unregistered temporary field proxies
* (piggy-backing on a chunk of existing memory as e.g., a numpy
* array) *efficiently*, the `get_ptr_to_entry` methods need to be
* branchless. this means that we cannot decide on the fly whether
* to return pointers pointing into values or into alt_values, we
* need to maintain an (shudder) raw data pointer that is set
* either at construction (for unregistered fields) or at any
* resize event (which may invalidate existing pointers). For the
* coder, this means that they need to be absolutely vigilant that
* *any* operation on the values vector that invalidates iterators
* needs to be followed by an update of data_ptr, or we will get
* super annoying memory bugs.
*/
T* data_ptr{};
private:
};
/* ---------------------------------------------------------------------- */
/* Implementations */
/* ---------------------------------------------------------------------- */
template <class FieldCollection, typename T>
TypedField<FieldCollection, T>::
TypedField(std::string unique_name, FieldCollection & collection,
size_t nb_components):
Parent(unique_name, nb_components, collection), current_size{0}
{}
/* ---------------------------------------------------------------------- */
template <class FieldCollection, typename T>
TypedField<FieldCollection, T>::
TypedField(std::string unique_name, FieldCollection & collection,
Eigen::Ref<Eigen::Matrix<Real, Eigen::Dynamic, 1>> vec,
size_t nb_components):
Parent(unique_name, nb_components, collection),
alt_values{vec}, current_size{vec.size()/nb_components},
data_ptr{vec.data()}
{
if (vec.size()%nb_components) {
std::stringstream err{};
err << "The vector you supplied has a size of " << vec.size()
<< ", which is not a multiple of the number of components ("
<< nb_components << ")";
throw FieldError(err.str());
}
if (current_size != collection.size()) {
std::stringstream err{};
err << "The vector you supplied has the size for " << current_size
<< " pixels with " << nb_components << "components each, but the "
<< "field collection has " << collection.size() << " pixels.";
throw FieldError(err.str());
}
}
/* ---------------------------------------------------------------------- */
//! return type_id of stored type
template <class FieldCollection, typename T>
const std::type_info & TypedField<FieldCollection, T>::
get_stored_typeid() const {
return typeid(T);
}
/* ---------------------------------------------------------------------- */
template <class FieldCollection, typename T>
auto TypedField<FieldCollection, T>::eigen() -> EigenMap_t {
return EigenMap_t(this->data(), this->get_nb_components(), this->size());
}
/* ---------------------------------------------------------------------- */
template <class FieldCollection, typename T>
auto TypedField<FieldCollection, T>::eigenvec() -> EigenVec_t {
return EigenVec_t(this->data(), this->get_nb_components() * this->size());
}
/* ---------------------------------------------------------------------- */
template <class FieldCollection, typename T>
auto TypedField<FieldCollection, T>:: eigenvec() const -> EigenVecConst_t {
return EigenVecConst_t(this->data(), this->get_nb_components() * this->size());
}
/* ---------------------------------------------------------------------- */
template <class FieldCollection, typename T>
auto TypedField<FieldCollection, T>:: const_eigenvec() const -> EigenVecConst_t {
return EigenVecConst_t(this->data(), this->get_nb_components() * this->size());
}
/* ---------------------------------------------------------------------- */
template <class FieldCollection, typename T>
void TypedField<FieldCollection, T>::resize(size_t size) {
if (this->alt_values) {
throw FieldError("Field proxies can't resize.");
}
this->current_size = size;
this->values.resize(size*this->get_nb_components() + this->pad_size);
this->data_ptr = &this->values.front();
}
/* ---------------------------------------------------------------------- */
template <class FieldCollection, typename T>
void TypedField<FieldCollection, T>::set_zero() {
std::fill(this->values.begin(), this->values.end(), T{});
}
/* ---------------------------------------------------------------------- */
template <class FieldCollection, typename T>
size_t TypedField<FieldCollection, T>::
size() const {
return this->current_size;
}
/* ---------------------------------------------------------------------- */
template <class FieldCollection, typename T>
void TypedField<FieldCollection, T>::
set_pad_size(size_t pad_size) {
if (this->alt_values) {
throw FieldError("You can't set the pad size of a field proxy.");
}
this->pad_size = pad_size;
this->resize(this->size());
this->data_ptr = &this->values.front();
}
/* ---------------------------------------------------------------------- */
template <class FieldCollection, typename T>
T* TypedField<FieldCollection, T>::
get_ptr_to_entry(const size_t&& index) {
return this->data_ptr + this->get_nb_components()*std::move(index);
}
/* ---------------------------------------------------------------------- */
template <class FieldCollection, typename T>
const T* TypedField<FieldCollection, T>::
get_ptr_to_entry(const size_t&& index) const {
return this->data_ptr+this->get_nb_components()*std::move(index);
}
/* ---------------------------------------------------------------------- */
template <class FieldCollection, typename T>
void TypedField<FieldCollection, T>::
push_back(const Stored_t & value) {
static_assert (not FieldCollection::Global,
"You can only push_back data into local field collections");
if (value.cols() != 1) {
std::stringstream err{};
err << "Expected a column vector, but received and array with "
<< value.cols() <<" colums.";
throw FieldError(err.str());
}
if (value.rows() != static_cast<Int>(this->get_nb_components())) {
std::stringstream err{};
err << "Expected a column vector of length " << this->get_nb_components()
<< ", but received one of length " << value.rows() <<".";
throw FieldError(err.str());
}
for (size_t i = 0; i < this->get_nb_components(); ++i) {
this->values.push_back(value(i));
}
++this->current_size;
this->data_ptr = &this->values.front();
}
} // muSpectre
#endif /* FIELD_TYPED_H */

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