Edit File: apr_mmap.h
/* Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #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; /** 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 to 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. */ APR_DECLARE(apr_status_t) apr_mmap_dup(apr_mmap_t **new_mmap, apr_mmap_t *old_mmap, apr_pool_t *p); /** * 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 */
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