transformation operators in C++.]

Templated interface to vector reduction/transformation operators {abstract}. More...

#include <RTOpPack_RTOpT_decl.hpp>

Inheritance diagram for RTOpPack::RTOpT< Scalar >:


public types
typedef PrimitiveTypeTraits< Scalar, Scalar >::primitiveType	primitive_value_type

Reduction object functions (NVI)
void	get_reduct_type_num_entries (const Ptr< int > &num_values, const Ptr< int > &num_indexes, const Ptr< int > &num_chars) const
	Get the number of entries of each basic data type in the externalized state for a reduction object for this operator.
Teuchos::RCP< ReductTarget >	reduct_obj_create () const
	Creates a new reduction target object initialized and ready to be used in a reduction.
void	reduce_reduct_objs (const ReductTarget &in_reduct_obj, const Ptr< ReductTarget > &inout_reduct_obj) const
	Reduce intermediate reduction target objects.
void	reduct_obj_reinit (const Ptr< ReductTarget > &reduct_obj) const
	Reinitialize an already created reduction object.
void	extract_reduct_obj_state (const ReductTarget &reduct_obj, const ArrayView< primitive_value_type > &value_data, const ArrayView< index_type > &index_data, const ArrayView< char_type > &char_data) const
	Extract the state of an already created reduction object.
void	load_reduct_obj_state (const ArrayView< const primitive_value_type > &value_data, const ArrayView< const index_type > &index_data, const ArrayView< const char_type > &char_data, const Ptr< ReductTarget > &reduct_obj) const
	Load the state of an already created reduction object given arrays of primitive objects.
Operator functions (NIV)
const std::string	op_name () const
	Return the name (as a null-terminated C-style string) of the operator.
bool	coord_invariant () const
	Returns `true` if this operator is coordinate invariant.
void	apply_op (const ArrayView< const ConstSubVectorView< Scalar > > &sub_vecs, const ArrayView< const SubVectorView< Scalar > > &targ_sub_vecs, const Ptr< ReductTarget > &reduct_obj) const
	Apply the reduction/transformation operator to a set of sub-vectors.
Deprecated (NVI)
void	get_reduct_type_num_entries (int num_values, int num_indexes, int *num_chars) const
	Deprecated.
void	reduce_reduct_objs (const ReductTarget &in_reduct_obj, ReductTarget *inout_reduct_obj) const
	Deprecated.
void	reduct_obj_reinit (ReductTarget *reduct_obj) const
	Deprecated.
void	extract_reduct_obj_state (const ReductTarget &reduct_obj, int num_values, primitive_value_type value_data[], int num_indexes, index_type index_data[], int num_chars, char_type char_data[]) const
	Deprecated.
void	load_reduct_obj_state (int num_values, const primitive_value_type value_data[], int num_indexes, const index_type index_data[], int num_chars, const char_type char_data[], ReductTarget *reduct_obj) const
	Deprecated.
void	apply_op (const int num_vecs, const ConstSubVectorView< Scalar > sub_vecs[], const int num_targ_vecs, const SubVectorView< Scalar > targ_sub_vecs[], ReductTarget *reduct_obj) const
	Deprecated.
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virtual void	get_reduct_type_num_entries_impl (const Ptr< int > &num_values, const Ptr< int > &num_indexes, const Ptr< int > &num_chars) const

virtual Teuchos::RCP< ReductTarget >	reduct_obj_create_impl () const

virtual void	reduce_reduct_objs_impl (const ReductTarget &in_reduct_obj, const Ptr< ReductTarget > &inout_reduct_obj) const

virtual void	reduct_obj_reinit_impl (const Ptr< ReductTarget > &reduct_obj) const

virtual void	extract_reduct_obj_state_impl (const ReductTarget &reduct_obj, const ArrayView< primitive_value_type > &value_data, const ArrayView< index_type > &index_data, const ArrayView< char_type > &char_data) const

virtual void	load_reduct_obj_state_impl (const ArrayView< const primitive_value_type > &value_data, const ArrayView< const index_type > &index_data, const ArrayView< const char_type > &char_data, const Ptr< ReductTarget > &reduct_obj) const

virtual const std::string	op_name_impl () const

virtual bool	coord_invariant_impl () const

virtual void	apply_op_impl (const ArrayView< const ConstSubVectorView< Scalar > > &sub_vecs, const ArrayView< const SubVectorView< Scalar > > &targ_sub_vecs, const Ptr< ReductTarget > &reduct_obj) const =0

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	RTOpT (const std::string &op_name_base="")
	Constructor that creates an operator name appended with the type.
void	setOpNameBase (const std::string &op_name_base)
	Just set the opeator name.

Detailed Description

template<class Scalar>
class RTOpPack::RTOpT< Scalar >

Templated interface to vector reduction/transformation operators {abstract}.

The purpose of this base class is to allow users to specify arbitrary reduction/transformation operations on vectors without requiring the vectors to reveal their implementation details. The design is motivated partly by the "Visitor" patter (Gamma, 1995).

This interface is designed to allow implementation of a distributed parallel abstract numerical algorithm without the explicit knowledge of the algorithm.

In the following discussion, v[k], x, y and z are some abstract vector objects of dimension n. Users can define operators to perform reduction and/or transformation operations. Reduction operations applied over all of the elements of a vector require communication between nodes in a parallel environment but do not change any of the vectors involved. Transformation operations don't require communication between nodes in a parallel environment. The targets of a transformation operation is a set of one or more vectors which are changed in some way.

The idea is that the user may want to perform reduction operations of the form:


 op(v[0]...v[*],z[0]...z[*]) -> reduct_obj

where reduct_obj is a single object based on a reduction over all the elements of the vector arguments, or transformation operations of the form:


 op(v[0](i)...v[*](i),z[0](i)...z[*](i)) -> z[0](i)...z[*](i), for i = 0...n-1

Operators can also be defined that perform reduction and transformation operations on the same vectors that that should only be done for efficiency reasons.

The tricky part though, is that the reduct_obj object of the reduction operation may be more complex than a single scalar value. For instance, it could be a double and an int pair such as in the reduction operation:


 min{ |x(i)|, i = 0...n-1 } -> [ x(j_min), j_min ]

or it could perform several reductions at once and store several scalar values such as in:


 min_max_sum{ x(i), i = 0...n-1 } -> [ x(j_min), j_min, x(j_max), j_max, x_sum ]

Transformation operations are much simpler to think about and to deal with. Some off-the-wall examples of transformation operations that this design will support are:


 max{ |x(i)|, |y(i)| } + |z(i)| -> z(i), for i = 0...n-1
 
 alpha * |z(i)| / x(i) -> z(i), for i = 0...n-1
 
 alpha * x(i) * y(i) + beta * z(i) -> z(i), for i = 0...n-1

Reduction operations present the more difficult technical challenge since they require information gathered from all of the elements to arrive at the final result. This design allows operator classes to be defined that can simultaneously perform reduction and transformation operations:


   op(v[0](i)...v[*](i),z[0](i)...z[*](i)) -> z[0](i)...z[*](i),reduct_obj
      , for i = 0...n-1

This design is based on a few assumptions about the reduction and transformation operations and vector implementations themselves. First, we will assume that vectors are stored and manipulated as chunks of sub-vectors (of dimension subDim) where each sub-vector is sufficiently large to overcome the inherent overhead of this design. This design supports dense strided sub-vectors (see ConstSubVectorView and SubVectorView) but is relatively flexible.

It is strictly the responsibility of the vector implementations to determine how these operators are applied. For instance, if we are performing a transformation operation of the form:


 op( x(i), y(i), z(i) ) -> z(i), for i = 0...n-1

where x, y, and z are distributed parallel vectors, then we would assume that the elements would be partitioned onto the various processors with the same local elements stored on each processor so as not to require any communication between processors.

Member Typedef Documentation

template<class Scalar>

typedef PrimitiveTypeTraits<Scalar,Scalar>::primitiveType RTOpPack::RTOpT< Scalar >::primitive_value_type

Constructor & Destructor Documentation

template<class Scalar>

RTOpPack::RTOpT< Scalar >::RTOpT ( const std::string & op_name_base = "" ) [protected]

Constructor that creates an operator name appended with the type.

Member Function Documentation

template<class Scalar>

void RTOpPack::RTOpT< Scalar >::get_reduct_type_num_entries ( const Ptr< int > & num_values,

const Ptr< int > & num_indexes,

const Ptr< int > & num_chars

) const [inline]

Get the number of entries of each basic data type in the externalized state for a reduction object for this operator.
Note that a specific reduction object is not passed in as an argument. This is because the structure of a reduction object is completely determined by its associated operator object and this structure can not change as a result of a reduction operation (this is needed to simplify global communication code when used * with MPI).
The default implementation returns zeros for *num_values, *num_indexes and *num_chars (i.e. by default there is no reduction operation performed).

template<class Scalar>

Teuchos::RCP<ReductTarget> RTOpPack::RTOpT< Scalar >::reduct_obj_create ( ) const [inline]

Creates a new reduction target object initialized and ready to be used in a reduction.
To delete this object simply let the returned RCP<> object go out of scope.
The default implementation returns return.get()==NULL (i.e. by default there is no reduction operation performed).

template<class Scalar>

void RTOpPack::RTOpT< Scalar >::reduce_reduct_objs ( const ReductTarget & in_reduct_obj,

const Ptr< ReductTarget > & inout_reduct_obj

) const [inline]

Reduce intermediate reduction target objects.
The default implementation does not do anything (i.e. by default there is no reduction operation performed).

template<class Scalar>

void RTOpPack::RTOpT< Scalar >::reduct_obj_reinit ( const Ptr< ReductTarget > & reduct_obj ) const [inline]

Reinitialize an already created reduction object.
The default implementation does nothing (i.e. by default there is no reduction operation performed).

Parameters:

reduct_obj [in/out] Reduction object is reinitialized on output.

template<class Scalar>

void RTOpPack::RTOpT< Scalar >::extract_reduct_obj_state ( const ReductTarget & reduct_obj,

const ArrayView< primitive_value_type > & value_data,

const ArrayView< index_type > & index_data,

const ArrayView< char_type > & char_data

) const [inline]

Extract the state of an already created reduction object.
This method allows the state of a reduction target object to be externalized so that it can be passed over a heterogeneous network of computers.
The default implementation does nothing (i.e. by default there is no reduction operation performed).

template<class Scalar>

void RTOpPack::RTOpT< Scalar >::load_reduct_obj_state ( const ArrayView< const primitive_value_type > & value_data,

const ArrayView< const index_type > & index_data,

const ArrayView< const char_type > & char_data,

const Ptr< ReductTarget > & reduct_obj

) const [inline]

Load the state of an already created reduction object given arrays of primitive objects.
The default implementation does nothing.

template<class Scalar>

const std::string RTOpPack::RTOpT< Scalar >::op_name ( ) const [inline]

Return the name (as a null-terminated C-style string) of the operator.
This name is used to differentiate an operator subclass from all other operator subclasses. This is an important property needed for a client/server or master/slave runtime configuration.
The default implementation uses the value created in the constructor RTOpT().

template<class Scalar>

bool RTOpPack::RTOpT< Scalar >::coord_invariant ( ) const [inline]

Returns true if this operator is coordinate invariant.
The default implementation returns true as most vector operators are coordinate invariant.

template<class Scalar>

void RTOpPack::RTOpT< Scalar >::apply_op ( const ArrayView< const ConstSubVectorView< Scalar > > & sub_vecs,

const ArrayView< const SubVectorView< Scalar > > & targ_sub_vecs,

const Ptr< ReductTarget > & reduct_obj

) const [inline]

Apply the reduction/transformation operator to a set of sub-vectors.
op(sub_vecs[],targ_sub_vecs[]),reduct_obj) -> targ_sub_vecs[],reduct_obj.
This is the bread and butter of the whole design. Through this method, a vector implementation applies a reduction/transformation operator to a set of sub-vectors.

Parameters:

num_vecs [in] Number of non-mutable sub-vectors in sub_vec[].

sub_vecs [in] Array (length num_vecs) of non-mutable vectors to apply the operator over. The ordering of these sub-vectors sub_vecs[k], for k = 0...num_vecs-1, is significant to the this operator object. If num_vecs==0 then sub_vecs can be NULL.

num_targ_vecs [in] Number of mutable sub-vectors in targ_sub_vec[].

targ_sub_vecs [in/out] Array (length num_targ_vecs) of mutable vectors to apply the operator over and be mutated. The ordering of these sub-vectors targ_sub_vecs[k], for k = 0...num_targ_vecs-1, is significant to this operator object. If num_targ_vecs==0 then targ_sub_vecs can be NULL.

reduct_obj [in/out] This reduction object must have been created by a this->reduct_obj_create() call and it may have * already passed through one or more other reduction operations (accumulating the reductions along the way). If this->get_reduct_type_num_entries() returns num_values==0, num_indexes==0 and num_chars==0, then reduct_obj should be set to NULL as no reduction will be performed.

Preconditions:

num_vecs > 0 || num_targ_vecs > 0

[num_vecs > 0] sub_vecs != NULL

[num_targ_vecs > 0] targ_sub_vecs != NULL

[num_vecs > 0] globalOffset==sub_vecs[k].globalOffset , for k = 0,...,num_vecs-1

[num_targ_vecs > 0] globalOffset==targ_sub_vecs[k].globalOffset , for k = 0,...,num_targ_vecs-1

[num_vecs > 0] subDim==sub_vecs[k].subDim() , for k = 0,...,num_vecs-1

[num_targ_vecs > 0] subDim==targ_sub_vecs[k].subDim() , for k = 0,...,num_targ_vecs-1

If reduct_obj != NULL then the reduction operation will be accumulated as:

op(op(sub_vecs[],targ_sub_vecs[]),reduct_obj) -> reduct_obj
By allowing an in/out reduct_obj and an accumulation of the reduction, the maximum reuse of memory is achieved. If this->reduct_obj_create() or this->reduct_obj_reinit() (passing in reduct_obj) was called immediately before this function, then on return, reduct_obj will contain only the reduction from this function call.
If num_vecs is incompatible with the underlying operator object then InvalidNumVecs is thrown. If the sub-vectors are not compatible (i.e. globalOffset and/or subDim not the same) then IncompatibleVecs is thrown.

template<class Scalar>

void RTOpPack::RTOpT< Scalar >::get_reduct_type_num_entries ( int * num_values,

int * num_indexes,

int * num_chars

) const [inline]

Deprecated.

template<class Scalar>

void RTOpPack::RTOpT< Scalar >::reduce_reduct_objs ( const ReductTarget & in_reduct_obj,

ReductTarget * inout_reduct_obj

) const [inline]

Deprecated.

template<class Scalar>

void RTOpPack::RTOpT< Scalar >::reduct_obj_reinit ( ReductTarget * reduct_obj ) const [inline]

Deprecated.

template<class Scalar>

void RTOpPack::RTOpT< Scalar >::extract_reduct_obj_state ( const ReductTarget & reduct_obj,

int num_values,

primitive_value_type value_data[],

int num_indexes,

index_type index_data[],

int num_chars,

char_type char_data[]

) const [inline]

Deprecated.

template<class Scalar>

void RTOpPack::RTOpT< Scalar >::load_reduct_obj_state ( int num_values,

const primitive_value_type value_data[],

int num_indexes,

const index_type index_data[],

int num_chars,

const char_type char_data[],

ReductTarget * reduct_obj

) const [inline]

Deprecated.

template<class Scalar>

void RTOpPack::RTOpT< Scalar >::apply_op ( const int num_vecs,

const ConstSubVectorView< Scalar > sub_vecs[],

const int num_targ_vecs,

const SubVectorView< Scalar > targ_sub_vecs[],

ReductTarget * reduct_obj

) const [inline]

Deprecated.

template<class Scalar>

void RTOpPack::RTOpT< Scalar >::get_reduct_type_num_entries_impl ( const Ptr< int > & num_values,

const Ptr< int > & num_indexes,

const Ptr< int > & num_chars

) const [protected, virtual]

template<class Scalar>

Teuchos::RCP< ReductTarget > RTOpPack::RTOpT< Scalar >::reduct_obj_create_impl ( ) const [protected, virtual]

template<class Scalar>

void RTOpPack::RTOpT< Scalar >::reduce_reduct_objs_impl ( const ReductTarget & in_reduct_obj,

const Ptr< ReductTarget > & inout_reduct_obj

) const [protected, virtual]

template<class Scalar>

void RTOpPack::RTOpT< Scalar >::reduct_obj_reinit_impl ( const Ptr< ReductTarget > & reduct_obj ) const [protected, virtual]

template<class Scalar>

void RTOpPack::RTOpT< Scalar >::extract_reduct_obj_state_impl ( const ReductTarget & reduct_obj,

const ArrayView< primitive_value_type > & value_data,

const ArrayView< index_type > & index_data,

const ArrayView< char_type > & char_data

) const [protected, virtual]

template<class Scalar>

void RTOpPack::RTOpT< Scalar >::load_reduct_obj_state_impl ( const ArrayView< const primitive_value_type > & value_data,

const ArrayView< const index_type > & index_data,

const ArrayView< const char_type > & char_data,

const Ptr< ReductTarget > & reduct_obj

) const [protected, virtual]

template<class Scalar>

const std::string RTOpPack::RTOpT< Scalar >::op_name_impl ( ) const [protected, virtual]

template<class Scalar>

bool RTOpPack::RTOpT< Scalar >::coord_invariant_impl ( ) const [protected, virtual]

template<class Scalar>

virtual void RTOpPack::RTOpT< Scalar >::apply_op_impl ( const ArrayView< const ConstSubVectorView< Scalar > > & sub_vecs,

const ArrayView< const SubVectorView< Scalar > > & targ_sub_vecs,

const Ptr< ReductTarget > & reduct_obj

) const [protected, pure virtual]

template<class Scalar>

void RTOpPack::RTOpT< Scalar >::setOpNameBase ( const std::string & op_name_base ) [protected]

Just set the opeator name.

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

RTOpPack_RTOpT_decl.hpp
RTOpPack_RTOpT_def.hpp

Generated on Sun Nov 23 12:11:45 2008 for Fundamental Vector Reduction/Transformation Operator (RTOp) Interfaces by

1.3.9.1

RTOpPack::RTOpT< Scalar > Class Template Reference [Templated interfaces for generalized vector reduction/transformation operators in C++.]

public types

Reduction object functions (NVI)

Operator functions (NIV)

Deprecated (NVI)

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