openPMD::detail::PreloadAdiosAttributes Class Reference

Class that is responsible for scheduling and buffering openPMD attribute loads from ADIOS2, if using ADIOS variables to store openPMD attributes. More...

#include <ADIOS2PreloadAttributes.hpp>

Classes
struct	AttributeLocation
	Internally used struct to store meta information on a buffered attribute. More...

Public Member Functions
	PreloadAdiosAttributes (PreloadAdiosAttributes const &other)=delete
PreloadAdiosAttributes &	operator= (PreloadAdiosAttributes const &other)=delete
	PreloadAdiosAttributes (PreloadAdiosAttributes &&other)=default
PreloadAdiosAttributes &	operator= (PreloadAdiosAttributes &&other)=default
void	preloadAttributes (adios2::IO &IO, adios2::Engine &engine)
	Schedule attributes for preloading. More...
template<typename T >
AttributeWithShape< T >	getAttribute (std::string const &name) const
	Get an attribute that has been buffered previously. More...
Datatype	attributeType (std::string const &name) const

Detailed Description

Class that is responsible for scheduling and buffering openPMD attribute loads from ADIOS2, if using ADIOS variables to store openPMD attributes.

Reasoning: ADIOS variables can be of any shape and size, and ADIOS cannot know which variables to buffer. While it will preload and buffer scalar variables, openPMD also stores vector-type attributes which are not preloaded. Since in Streaming setups, every variable load requires full communication back to the writer, this can quickly become very expensive. Hence, do this manually.

Member Function Documentation

getAttribute()

template<typename T >

AttributeWithShape< T > openPMD::detail::PreloadAdiosAttributes::getAttribute

(

std::string const &

name

)

const

Get an attribute that has been buffered previously.

Template Parameters

T	The underlying primitive datatype of the attribute. Will fail if the type found in ADIOS does not match.

Parameters

name	The full name of the attribute.

Returns

Pointer to the buffered attribute along with information on the attribute's shape. Valid only until any non-const member of PreloadAdiosAttributes is called.

preloadAttributes()

void openPMD::detail::PreloadAdiosAttributes::preloadAttributes	(	adios2::IO &	IO,
		adios2::Engine &	engine
	)

Schedule attributes for preloading.

This will invalidate all previously buffered attributes. This will not flush the scheduled loads. This way, attributes can be loaded along with the next adios2::Engine flush.

Parameters

IO
engine

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

• /tmp/tmp.7iNmvGSbic/openPMD-api/include/openPMD/IO/ADIOS/ADIOS2PreloadAttributes.hpp
• /tmp/tmp.7iNmvGSbic/openPMD-api/src/IO/ADIOS/ADIOS2PreloadAttributes.cpp