osmium::util::TypedMemoryMapping< T > Class Template Reference

#include <memory_mapping.hpp>

Inheritance diagram for osmium::util::TypedMemoryMapping< T >:

Collaboration diagram for osmium::util::TypedMemoryMapping< T >:

Public Member Functions
	TypedMemoryMapping (std::size_t size)
	TypedMemoryMapping (std::size_t size, MemoryMapping::mapping_mode mode, int fd, off_t offset=0)
	TypedMemoryMapping (const TypedMemoryMapping &)=delete
	You can not copy construct a TypedMemoryMapping. More...
TypedMemoryMapping &	operator= (const TypedMemoryMapping &)=delete
	You can not copy a TypedMemoryMapping. More...
	TypedMemoryMapping (TypedMemoryMapping &&other) noexcept=default
TypedMemoryMapping &	operator= (TypedMemoryMapping &&other) noexcept=default
	~TypedMemoryMapping () noexcept=default
void	unmap ()
void	resize (std::size_t new_size)
	operator bool () const noexcept
std::size_t	size () const noexcept
int	fd () const noexcept
bool	writable () const noexcept
T *	begin () noexcept
T *	end () noexcept
const T *	cbegin () const noexcept
const T *	cend () const noexcept
const T *	begin () const noexcept
const T *	end () const noexcept

Private Attributes
MemoryMapping	m_mapping

Detailed Description

template<typename T>
class osmium::util::TypedMemoryMapping< T >

A thin wrapper around the MemoryMapping class used when all the data in the mapped memory is of the same type. Instead of thinking about the number of bytes mapped, this counts sizes in the number of objects of that type.

Note that no effort is made to actually initialize the objects in this memory. This has to be done by the caller!

Constructor & Destructor Documentation

TypedMemoryMapping() [1/4]

template<typename T >

osmium::util::TypedMemoryMapping< T >::TypedMemoryMapping ( std::size_t  size )

inlineexplicit

Create anonymous typed memory mapping of given size.

Parameters

size	Number of objects of type T to be mapped

Exceptions

std::system_error

if the mapping fails

TypedMemoryMapping() [2/4]

template<typename T >

osmium::util::TypedMemoryMapping< T >::TypedMemoryMapping ( std::size_t  size, MemoryMapping::mapping_mode  mode, int  fd, off_t  offset = 0  )

inline

Create file-backed memory mapping of given size. The file must contain at least sizeof(T) * size bytes!

Parameters

size	Number of objects of type T to be mapped
mode	Mapping mode: readonly, or writable (shared or private)
fd	Open file descriptor of a file we want to map
offset	Offset into the file where the mapping should start

Exceptions

std::system_error

if the mapping fails

TypedMemoryMapping() [3/4]

template<typename T >

osmium::util::TypedMemoryMapping< T >::TypedMemoryMapping ( const TypedMemoryMapping< T > &  )

delete

You can not copy construct a TypedMemoryMapping.

TypedMemoryMapping() [4/4]

template<typename T >

osmium::util::TypedMemoryMapping< T >::TypedMemoryMapping ( TypedMemoryMapping< T > &&  other )

defaultnoexcept

Move construct a mapping from another one. The other mapping will be marked as invalid.

~TypedMemoryMapping()

template<typename T >

osmium::util::TypedMemoryMapping< T >::~TypedMemoryMapping ( )

defaultnoexcept

Releases the mapping by calling unmap(). Will never throw. Call unmap() instead if you want to be notified of any error.

Member Function Documentation

begin() [1/2]

template<typename T >

const T * osmium::util::TypedMemoryMapping< T >::begin ( ) const

inlinenoexcept

Get the address of the beginning of the mapping.

Precondition

is_valid()

begin() [2/2]

template<typename T >

T * osmium::util::TypedMemoryMapping< T >::begin ( )

inlinenoexcept

Get the address of the beginning of the mapping.

Precondition

is_valid()

cbegin()

template<typename T >

const T * osmium::util::TypedMemoryMapping< T >::cbegin ( ) const

inlinenoexcept

Get the address of the beginning of the mapping.

Precondition

is_valid()

cend()

template<typename T >

const T * osmium::util::TypedMemoryMapping< T >::cend ( ) const

inlinenoexcept

Get the address one past the end of the mapping.

Precondition

is_valid()

end() [1/2]

template<typename T >

const T * osmium::util::TypedMemoryMapping< T >::end ( ) const

inlinenoexcept

Get the address one past the end of the mapping.

Precondition

is_valid()

end() [2/2]

template<typename T >

T * osmium::util::TypedMemoryMapping< T >::end ( )

inlinenoexcept

Get the address one past the end of the mapping.

Precondition

is_valid()

fd()

template<typename T >

int osmium::util::TypedMemoryMapping< T >::fd ( ) const

inlinenoexcept

The file descriptor this mapping was created from.

Returns

file descriptor, -1 for anonymous mappings

operator bool()

template<typename T >

osmium::util::TypedMemoryMapping< T >::operator bool ( ) const

inlineexplicitnoexcept

In a boolean context a TypedMemoryMapping is true when it is a valid existing mapping.

operator=() [1/2]

template<typename T >

TypedMemoryMapping & osmium::util::TypedMemoryMapping< T >::operator= ( const TypedMemoryMapping< T > &  )

delete

You can not copy a TypedMemoryMapping.

operator=() [2/2]

template<typename T >

TypedMemoryMapping & osmium::util::TypedMemoryMapping< T >::operator= ( TypedMemoryMapping< T > &&  other )

defaultnoexcept

Move a mapping. The other mapping will be marked as invalid.

resize()

template<typename T >

void osmium::util::TypedMemoryMapping< T >::resize ( std::size_t  new_size )

inline

Resize a mapping to the given new size.

On Linux systems this will use the mremap() function. On other systems it will unmap and remap the memory. This can only be done for file-based mappings, not anonymous mappings!

Parameters

new_size

Number of objects of type T to resize to

Exceptions

std::system_error

if the remapping fails

size()

template<typename T >

std::size_t osmium::util::TypedMemoryMapping< T >::size ( ) const

inlinenoexcept

The number of objects of class T mapped. This is the same size you created the mapping with. The actual mapping will probably be larger because the system will round it to the page size.

unmap()

template<typename T >

void osmium::util::TypedMemoryMapping< T >::unmap ( )

inline

Unmap a mapping. If the mapping is not valid, it will do nothing.

Exceptions

std::system_error

if the unmapping fails

writable()

template<typename T >

bool osmium::util::TypedMemoryMapping< T >::writable ( ) const

inlinenoexcept

Was this mapping created as a writable mapping?

Member Data Documentation

m_mapping

template<typename T >

MemoryMapping osmium::util::TypedMemoryMapping< T >::m_mapping

private

---

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

• include/osmium/util/memory_mapping.hpp