MMAP (Memory Map) Routines
[Apache Portability Runtime library]

Data Structures
struct	apr_mmap_t
Defines
#define	APR_MMAP_READ   1
#define	APR_MMAP_WRITE   2
#define	APR_MMAP_THRESHOLD   1
#define	APR_MMAP_LIMIT   (4*1024*1024)
#define	APR_MMAP_CANDIDATE(filelength)   ((filelength >= APR_MMAP_THRESHOLD) && (filelength < APR_MMAP_LIMIT))
Typedefs
typedef apr_mmap_t	apr_mmap_t
Functions
apr_status_t	apr_mmap_create (apr_mmap_t **newmmap, apr_file_t *file, apr_off_t offset, apr_size_t size, apr_int32_t flag, apr_pool_t *cntxt)
apr_status_t	apr_mmap_dup (apr_mmap_t **new_mmap, apr_mmap_t *old_mmap, apr_pool_t *p, int transfer_ownership)
apr_status_t	apr_mmap_setaside (apr_mmap_t **new_mmap, apr_mmap_t *old_mmap, apr_pool_t *p)
apr_status_t	apr_mmap_delete (apr_mmap_t *mm)
apr_status_t	apr_mmap_offset (void **addr, apr_mmap_t *mm, apr_off_t offset)

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Define Documentation

#define APR_MMAP_CANDIDATE

(

filelength

)

((filelength >= APR_MMAP_THRESHOLD) && (filelength < APR_MMAP_LIMIT))

Can this file be MMaped

#define APR_MMAP_LIMIT   (4*1024*1024)

Maximum size of MMap region

#define APR_MMAP_READ   1

MMap opened for reading

#define APR_MMAP_THRESHOLD   1

Files have to be at least this big before they're mmap()d. This is to deal with systems where the expense of doing an mmap() and an munmap() outweighs the benefit for small files. It shouldn't be set lower than 1.

#define APR_MMAP_WRITE   2

MMap opened for writing

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Typedef Documentation

typedef struct apr_mmap_t apr_mmap_t

See also:

apr_mmap_t

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Function Documentation

apr_status_t apr_mmap_create	(	apr_mmap_t **	newmmap,
		apr_file_t *	file,
		apr_off_t	offset,
		apr_size_t	size,
		apr_int32_t	flag,
		apr_pool_t *	cntxt
	)

Create a new mmap'ed file out of an existing APR file.

Parameters:

	newmmap	The newly created mmap'ed file.
	file	The file turn into an mmap.
	offset	The offset into the file to start the data pointer at.
	size	The size of the file
	flag	bit-wise or of: APR_MMAP_READ MMap opened for reading APR_MMAP_WRITE MMap opened for writing
	cntxt	The pool to use when creating the mmap.

apr_status_t apr_mmap_delete

(

apr_mmap_t *

mm

)

Remove a mmap'ed.

Parameters:

mm

The mmap'ed file.

apr_status_t apr_mmap_dup	(	apr_mmap_t **	new_mmap,
		apr_mmap_t *	old_mmap,
		apr_pool_t *	p,
		int	transfer_ownership
	)

Duplicate the specified MMAP.

Parameters:

	new_mmap	The structure to duplicate into.
	old_mmap	The mmap to duplicate.
	p	The pool to use for new_mmap.
	transfer_ownership	DEPRECATED: this param is now ignored and should be removed prior to APR 1.0

apr_status_t apr_mmap_offset	(	void **	addr,
		apr_mmap_t *	mm,
		apr_off_t	offset
	)

Move the pointer into the mmap'ed file to the specified offset.

Parameters:

	addr	The pointer to the offset specified.
	mm	The mmap'ed file.
	offset	The offset to move to.

apr_status_t apr_mmap_setaside	(	apr_mmap_t **	new_mmap,
		apr_mmap_t *	old_mmap,
		apr_pool_t *	p
	)

Transfer the specified MMAP to a different pool

Parameters:

	new_mmap	The structure to duplicate into.
	old_mmap	The file to transfer.
	p	The pool to use for new_mmap.

Deprecated:

Just use apr_mmap_dup(). The transfer_ownership flag will go away soon anyway.

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