MMAP (Memory Map) Routines

Data Structures
struct	apr_mmap_t

Macros
#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 struct 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)
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)

Detailed Description

Macro Definition 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

Typedef Documentation

typedef struct apr_mmap_t apr_mmap_t

See also

apr_mmap_t

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 to 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
	)

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.

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.