TGD::MmapAllocator Class Reference

An mmap-based allocator that allows to work with arrays that do not fit into main memory. More...

#include <alloc.hpp>

Inherits TGD::Allocator.

Public Types
enum	Type { Private , NewFile , ExistingFileReadOnly , ExistingFileReadWrite }

Public Member Functions
	MmapAllocator (const std::string &dirName=".")
	Constructor for a private mmap allocator.
	MmapAllocator (const std::string &fileName, Type type)
	Constructor for a named-file mmap allocator.
virtual	~MmapAllocator ()
	Destructor.
virtual unsigned char *	allocate (std::size_t n) const override
	Allocates n bytes.
virtual std::function< void(unsigned char *p)>	getDeallocator (std::size_t n) const override
	Returns a function that deallocates n bytes at the given pointer.
virtual bool	clearsMemory () const override
	Returns whether this allocator clears allocated memory.
Public Member Functions inherited from TGD::Allocator
	Allocator ()
	Constructor.
virtual	~Allocator ()
	Destructor.

Detailed Description

An mmap-based allocator that allows to work with arrays that do not fit into main memory.

Member Enumeration Documentation

Type

enum TGD::MmapAllocator::Type

Enumerator
Private	Allocation in a specific directory, without a visible file name.
NewFile	Shared allocation in a newly created file with a given name.
ExistingFileReadOnly	Shared allocation in an existing file, read only.
ExistingFileReadWrite	Shared allocation in an existing file, read and write.

Constructor & Destructor Documentation

MmapAllocator() [1/2]

TGD::MmapAllocator::MmapAllocator ( const std::string & dirName = "." )

inline

Constructor for a private mmap allocator.

Parameters

dirName

Directory in which the private file is created.

Creates a private temporary file in the given directory. Typical values for dirName are "." for the current directory, or a directory taken from the TMPDIR environment variable, if available.

MmapAllocator() [2/2]

TGD::MmapAllocator::MmapAllocator ( const std::string & fileName, Type type )

inline

Constructor for a named-file mmap allocator.

Parameters

fileName	Name of the file.
type	Type of file usage.

The type can be NewFile, which will create a new file (or possibly overwrites an existing file with the same name), or ExistingFileReadOnly, which will open the specified file in read-only mode, or ExistingFileReadWrite, which will open the specified file in read-write mode.

~MmapAllocator()

virtual TGD::MmapAllocator::~MmapAllocator ( )

inlinevirtual

Destructor.

Member Function Documentation

allocate()

virtual unsigned char * TGD::MmapAllocator::allocate ( std::size_t n ) const

inlineoverridevirtual

Allocates n bytes.

Reimplemented from TGD::Allocator.

clearsMemory()

virtual bool TGD::MmapAllocator::clearsMemory ( ) const

inlineoverridevirtual

Returns whether this allocator clears allocated memory.

Reimplemented from TGD::Allocator.

getDeallocator()

virtual std::function< void(unsigned char *p)> TGD::MmapAllocator::getDeallocator ( std::size_t n ) const

inlineoverridevirtual

Returns a function that deallocates n bytes at the given pointer.

Reimplemented from TGD::Allocator.

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

• alloc.hpp