github.com/krum110487/go-htaccess@v0.0.0-20240316004156-60641c8e7598/tests/data/apache_2_2_34/include/apr_mmap.h (about)

     1  /* Licensed to the Apache Software Foundation (ASF) under one or more
     2   * contributor license agreements.  See the NOTICE file distributed with
     3   * this work for additional information regarding copyright ownership.
     4   * The ASF licenses this file to You under the Apache License, Version 2.0
     5   * (the "License"); you may not use this file except in compliance with
     6   * the License.  You may obtain a copy of the License at
     7   *
     8   *     http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  
    17  #ifndef APR_MMAP_H
    18  #define APR_MMAP_H
    19  
    20  /**
    21   * @file apr_mmap.h
    22   * @brief APR MMAP routines
    23   */
    24  
    25  #include "apr.h"
    26  #include "apr_pools.h"
    27  #include "apr_errno.h"
    28  #include "apr_ring.h"
    29  #include "apr_file_io.h"        /* for apr_file_t */
    30  
    31  #ifdef BEOS
    32  #include <kernel/OS.h>
    33  #endif
    34  
    35  #ifdef __cplusplus
    36  extern "C" {
    37  #endif /* __cplusplus */
    38  
    39  /**
    40   * @defgroup apr_mmap MMAP (Memory Map) Routines
    41   * @ingroup APR 
    42   * @{
    43   */
    44  
    45  /** MMap opened for reading */
    46  #define APR_MMAP_READ    1
    47  /** MMap opened for writing */
    48  #define APR_MMAP_WRITE   2
    49  
    50  /** @see apr_mmap_t */
    51  typedef struct apr_mmap_t            apr_mmap_t;
    52  
    53  /**
    54   * @remark
    55   * As far as I can tell the only really sane way to store an MMAP is as a
    56   * void * and a length.  BeOS requires this area_id, but that's just a little
    57   * something extra.  I am exposing this type, because it doesn't make much
    58   * sense to keep it private, and opening it up makes some stuff easier in
    59   * Apache.
    60   */
    61  /** The MMAP structure */
    62  struct apr_mmap_t {
    63      /** The pool the mmap structure was allocated out of. */
    64      apr_pool_t *cntxt;
    65  #ifdef BEOS
    66      /** An area ID.  Only valid on BeOS */
    67      area_id area;
    68  #endif
    69  #ifdef WIN32
    70      /** The handle of the file mapping */
    71      HANDLE mhandle;
    72      /** The start of the real memory page area (mapped view) */
    73      void *mv;
    74      /** The physical start, size and offset */
    75      apr_off_t  pstart;
    76      apr_size_t psize;
    77      apr_off_t  poffset;
    78  #endif
    79      /** The start of the memory mapped area */
    80      void *mm;
    81      /** The amount of data in the mmap */
    82      apr_size_t size;
    83      /** ring of apr_mmap_t's that reference the same
    84       * mmap'ed region; acts in place of a reference count */
    85      APR_RING_ENTRY(apr_mmap_t) link;
    86  };
    87  
    88  #if APR_HAS_MMAP || defined(DOXYGEN)
    89  
    90  /** @def APR_MMAP_THRESHOLD 
    91   * Files have to be at least this big before they're mmap()d.  This is to deal
    92   * with systems where the expense of doing an mmap() and an munmap() outweighs
    93   * the benefit for small files.  It shouldn't be set lower than 1.
    94   */
    95  #ifdef MMAP_THRESHOLD
    96  #  define APR_MMAP_THRESHOLD              MMAP_THRESHOLD
    97  #else
    98  #  ifdef SUNOS4
    99  #    define APR_MMAP_THRESHOLD            (8*1024)
   100  #  else
   101  #    define APR_MMAP_THRESHOLD            1
   102  #  endif /* SUNOS4 */
   103  #endif /* MMAP_THRESHOLD */
   104  
   105  /** @def APR_MMAP_LIMIT
   106   * Maximum size of MMap region
   107   */
   108  #ifdef MMAP_LIMIT
   109  #  define APR_MMAP_LIMIT                  MMAP_LIMIT
   110  #else
   111  #  define APR_MMAP_LIMIT                  (4*1024*1024)
   112  #endif /* MMAP_LIMIT */
   113  
   114  /** Can this file be MMaped */
   115  #define APR_MMAP_CANDIDATE(filelength) \
   116      ((filelength >= APR_MMAP_THRESHOLD) && (filelength < APR_MMAP_LIMIT))
   117  
   118  /*   Function definitions */
   119  
   120  /** 
   121   * Create a new mmap'ed file out of an existing APR file.
   122   * @param newmmap The newly created mmap'ed file.
   123   * @param file The file to turn into an mmap.
   124   * @param offset The offset into the file to start the data pointer at.
   125   * @param size The size of the file
   126   * @param flag bit-wise or of:
   127   * <PRE>
   128   *          APR_MMAP_READ       MMap opened for reading
   129   *          APR_MMAP_WRITE      MMap opened for writing
   130   * </PRE>
   131   * @param cntxt The pool to use when creating the mmap.
   132   */
   133  APR_DECLARE(apr_status_t) apr_mmap_create(apr_mmap_t **newmmap, 
   134                                            apr_file_t *file, apr_off_t offset,
   135                                            apr_size_t size, apr_int32_t flag,
   136                                            apr_pool_t *cntxt);
   137  
   138  /**
   139   * Duplicate the specified MMAP.
   140   * @param new_mmap The structure to duplicate into. 
   141   * @param old_mmap The mmap to duplicate.
   142   * @param p The pool to use for new_mmap.
   143   */         
   144  APR_DECLARE(apr_status_t) apr_mmap_dup(apr_mmap_t **new_mmap,
   145                                         apr_mmap_t *old_mmap,
   146                                         apr_pool_t *p);
   147  
   148  /**
   149   * Remove a mmap'ed.
   150   * @param mm The mmap'ed file.
   151   */
   152  APR_DECLARE(apr_status_t) apr_mmap_delete(apr_mmap_t *mm);
   153  
   154  /** 
   155   * Move the pointer into the mmap'ed file to the specified offset.
   156   * @param addr The pointer to the offset specified.
   157   * @param mm The mmap'ed file.
   158   * @param offset The offset to move to.
   159   */
   160  APR_DECLARE(apr_status_t) apr_mmap_offset(void **addr, apr_mmap_t *mm, 
   161                                            apr_off_t offset);
   162  
   163  #endif /* APR_HAS_MMAP */
   164  
   165  /** @} */
   166  
   167  #ifdef __cplusplus
   168  }
   169  #endif
   170  
   171  #endif  /* ! APR_MMAP_H */