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 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 */ 172