Viewing file:  apr_mmap.h (7.69 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2000-2003 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
#ifndef APR_MMAP_H
#define APR_MMAP_H
/**
* @file apr_mmap.h
* @brief APR MMAP routines
*/
#include "apr.h"
#include "apr_pools.h"
#include "apr_errno.h"
#include "apr_ring.h"
#include "apr_file_io.h" /* for apr_file_t */
#ifdef BEOS
#include <kernel/OS.h>
#endif
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/**
* @defgroup apr_mmap MMAP (Memory Map) Routines
* @ingroup APR
* @{
*/
/** MMap opened for reading */
#define APR_MMAP_READ 1
/** MMap opened for writing */
#define APR_MMAP_WRITE 2
/** @see apr_mmap_t */
typedef struct apr_mmap_t apr_mmap_t;
/**
* @remark
* As far as I can tell the only really sane way to store an MMAP is as a
* void * and a length. BeOS requires this area_id, but that's just a little
* something extra. I am exposing this type, because it doesn't make much
* sense to keep it private, and opening it up makes some stuff easier in
* Apache.
*/
/** The MMAP structure */
struct apr_mmap_t {
/** The pool the mmap structure was allocated out of. */
apr_pool_t *cntxt;
#ifdef BEOS
/** An area ID. Only valid on BeOS */
area_id area;
#endif
#ifdef WIN32
/** The handle of the file mapping */
HANDLE mhandle;
/** The start of the real memory page area (mapped view) */
void *mv;
/** The physical start, size and offset */
apr_off_t pstart;
apr_size_t psize;
apr_off_t poffset;
#endif
/** The start of the memory mapped area */
void *mm;
/** The amount of data in the mmap */
apr_size_t size;
/** @deprecated this field is no longer used and will be removed
* in APR 1.0 */
int unused;
/** ring of apr_mmap_t's that reference the same
* mmap'ed region; acts in place of a reference count */
APR_RING_ENTRY(apr_mmap_t) link;
};
#if APR_HAS_MMAP || defined(DOXYGEN)
/** @def APR_MMAP_THRESHOLD
* 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.
*/
#ifdef MMAP_THRESHOLD
# define APR_MMAP_THRESHOLD MMAP_THRESHOLD
#else
# ifdef SUNOS4
# define APR_MMAP_THRESHOLD (8*1024)
# else
# define APR_MMAP_THRESHOLD 1
# endif /* SUNOS4 */
#endif /* MMAP_THRESHOLD */
/** @def APR_MMAP_LIMIT
* Maximum size of MMap region
*/
#ifdef MMAP_LIMIT
# define APR_MMAP_LIMIT MMAP_LIMIT
#else
# define APR_MMAP_LIMIT (4*1024*1024)
#endif /* MMAP_LIMIT */
/** Can this file be MMaped */
#define APR_MMAP_CANDIDATE(filelength) \
((filelength >= APR_MMAP_THRESHOLD) && (filelength < APR_MMAP_LIMIT))
/* Function definitions */
/**
* Create a new mmap'ed file out of an existing APR file.
* @param newmmap The newly created mmap'ed file.
* @param file The file turn into an mmap.
* @param offset The offset into the file to start the data pointer at.
* @param size The size of the file
* @param flag bit-wise or of:
* <PRE>
* APR_MMAP_READ MMap opened for reading
* APR_MMAP_WRITE MMap opened for writing
* </PRE>
* @param cntxt The pool to use when creating the mmap.
*/
APR_DECLARE(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);
/**
* Duplicate the specified MMAP.
* @param new_mmap The structure to duplicate into.
* @param old_mmap The mmap to duplicate.
* @param p The pool to use for new_mmap.
* @param transfer_ownership DEPRECATED: this param is now ignored
* and should be removed prior to APR 1.0
*/
APR_DECLARE(apr_status_t) apr_mmap_dup(apr_mmap_t **new_mmap,
apr_mmap_t *old_mmap,
apr_pool_t *p,
int transfer_ownership);
#if defined(DOXYGEN)
/**
* Transfer the specified MMAP to a different pool
* @param new_mmap The structure to duplicate into.
* @param old_mmap The file to transfer.
* @param p The pool to use for new_mmap.
* @deprecated Just use apr_mmap_dup(). The transfer_ownership flag will
* go away soon anyway.
*/
APR_DECLARE(apr_status_t) apr_mmap_setaside(apr_mmap_t **new_mmap,
apr_mmap_t *old_mmap,
apr_pool_t *p);
#else
#define apr_mmap_setaside(new_mmap, old_mmap, p) apr_mmap_dup(new_mmap, old_mmap, p, 1)
#endif /* DOXYGEN */
/**
* Remove a mmap'ed.
* @param mm The mmap'ed file.
*/
APR_DECLARE(apr_status_t) apr_mmap_delete(apr_mmap_t *mm);
/**
* Move the pointer into the mmap'ed file to the specified offset.
* @param addr The pointer to the offset specified.
* @param mm The mmap'ed file.
* @param offset The offset to move to.
*/
APR_DECLARE(apr_status_t) apr_mmap_offset(void **addr, apr_mmap_t *mm,
apr_off_t offset);
#endif /* APR_HAS_MMAP */
/** @} */
#ifdef __cplusplus
}
#endif
#endif /* ! APR_MMAP_H */
|