Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 1 | /* |
| 2 | * jmemsys.h |
| 3 | * |
DRC | 5033f3e | 2014-05-18 18:33:44 +0000 | [diff] [blame] | 4 | * This file was part of the Independent JPEG Group's software: |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 5 | * Copyright (C) 1992-1997, Thomas G. Lane. |
DRC | 5033f3e | 2014-05-18 18:33:44 +0000 | [diff] [blame] | 6 | * It was modified by The libjpeg-turbo Project to include only code and |
| 7 | * information relevant to libjpeg-turbo. |
DRC | 7e3acc0 | 2015-10-10 10:25:46 -0500 | [diff] [blame^] | 8 | * For conditions of distribution and use, see the accompanying README.ijg |
| 9 | * file. |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 10 | * |
| 11 | * This include file defines the interface between the system-independent |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 12 | * and system-dependent portions of the JPEG memory manager. No other |
| 13 | * modules need include it. (The system-independent portion is jmemmgr.c; |
| 14 | * there are several different versions of the system-dependent portion.) |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 15 | * |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 16 | * This file works as-is for the system-dependent memory managers supplied |
| 17 | * in the IJG distribution. You may need to modify it if you write a |
| 18 | * custom memory manager. If system-dependent changes are needed in |
| 19 | * this file, the best method is to #ifdef them based on a configuration |
DRC | 5033f3e | 2014-05-18 18:33:44 +0000 | [diff] [blame] | 20 | * symbol supplied in jconfig.h. |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 21 | */ |
| 22 | |
| 23 | |
| 24 | /* |
| 25 | * These two functions are used to allocate and release small chunks of |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 26 | * memory. (Typically the total amount requested through jpeg_get_small is |
| 27 | * no more than 20K or so; this will be requested in chunks of a few K each.) |
| 28 | * Behavior should be the same as for the standard library functions malloc |
| 29 | * and free; in particular, jpeg_get_small must return NULL on failure. |
| 30 | * On most systems, these ARE malloc and free. jpeg_free_small is passed the |
| 31 | * size of the object being freed, just in case it's needed. |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 32 | */ |
| 33 | |
DRC | bc56b75 | 2014-05-16 10:43:44 +0000 | [diff] [blame] | 34 | EXTERN(void *) jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject); |
| 35 | EXTERN(void) jpeg_free_small (j_common_ptr cinfo, void * object, |
| 36 | size_t sizeofobject); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 37 | |
| 38 | /* |
| 39 | * These two functions are used to allocate and release large chunks of |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 40 | * memory (up to the total free space designated by jpeg_mem_available). |
DRC | 5033f3e | 2014-05-18 18:33:44 +0000 | [diff] [blame] | 41 | * These are identical to the jpeg_get/free_small routines; but we keep them |
| 42 | * separate anyway, in case a different allocation strategy is desirable for |
| 43 | * large chunks. |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 44 | */ |
| 45 | |
DRC | 5033f3e | 2014-05-18 18:33:44 +0000 | [diff] [blame] | 46 | EXTERN(void *) jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject); |
| 47 | EXTERN(void) jpeg_free_large (j_common_ptr cinfo, void * object, |
DRC | bc56b75 | 2014-05-16 10:43:44 +0000 | [diff] [blame] | 48 | size_t sizeofobject); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 49 | |
| 50 | /* |
| 51 | * The macro MAX_ALLOC_CHUNK designates the maximum number of bytes that may |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 52 | * be requested in a single call to jpeg_get_large (and jpeg_get_small for that |
DRC | 5033f3e | 2014-05-18 18:33:44 +0000 | [diff] [blame] | 53 | * matter, but that case should never come into play). This macro was needed |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 54 | * to model the 64Kb-segment-size limit of far addressing on 80x86 machines. |
DRC | 5033f3e | 2014-05-18 18:33:44 +0000 | [diff] [blame] | 55 | * On machines with flat address spaces, any large constant may be used. |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 56 | * |
| 57 | * NB: jmemmgr.c expects that MAX_ALLOC_CHUNK will be representable as type |
| 58 | * size_t and will be a multiple of sizeof(align_type). |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 59 | */ |
| 60 | |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 61 | #ifndef MAX_ALLOC_CHUNK /* may be overridden in jconfig.h */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 62 | #define MAX_ALLOC_CHUNK 1000000000L |
| 63 | #endif |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 64 | |
| 65 | /* |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 66 | * This routine computes the total space still available for allocation by |
| 67 | * jpeg_get_large. If more space than this is needed, backing store will be |
| 68 | * used. NOTE: any memory already allocated must not be counted. |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 69 | * |
| 70 | * There is a minimum space requirement, corresponding to the minimum |
| 71 | * feasible buffer sizes; jmemmgr.c will request that much space even if |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 72 | * jpeg_mem_available returns zero. The maximum space needed, enough to hold |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 73 | * all working storage in memory, is also passed in case it is useful. |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 74 | * Finally, the total space already allocated is passed. If no better |
| 75 | * method is available, cinfo->mem->max_memory_to_use - already_allocated |
| 76 | * is often a suitable calculation. |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 77 | * |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 78 | * It is OK for jpeg_mem_available to underestimate the space available |
| 79 | * (that'll just lead to more backing-store access than is really necessary). |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 80 | * However, an overestimate will lead to failure. Hence it's wise to subtract |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 81 | * a slop factor from the true available space. 5% should be enough. |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 82 | * |
| 83 | * On machines with lots of virtual memory, any large constant may be returned. |
| 84 | * Conversely, zero may be returned to always use the minimum amount of memory. |
| 85 | */ |
| 86 | |
DRC | bc56b75 | 2014-05-16 10:43:44 +0000 | [diff] [blame] | 87 | EXTERN(size_t) jpeg_mem_available (j_common_ptr cinfo, size_t min_bytes_needed, |
| 88 | size_t max_bytes_needed, |
| 89 | size_t already_allocated); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 90 | |
| 91 | |
| 92 | /* |
| 93 | * This structure holds whatever state is needed to access a single |
| 94 | * backing-store object. The read/write/close method pointers are called |
| 95 | * by jmemmgr.c to manipulate the backing-store object; all other fields |
| 96 | * are private to the system-dependent backing store routines. |
| 97 | */ |
| 98 | |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 99 | #define TEMP_NAME_LENGTH 64 /* max length of a temporary file's name */ |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 100 | |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 101 | |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 102 | #ifdef USE_MSDOS_MEMMGR /* DOS-specific junk */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 103 | |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 104 | typedef unsigned short XMSH; /* type of extended-memory handles */ |
| 105 | typedef unsigned short EMSH; /* type of expanded-memory handles */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 106 | |
| 107 | typedef union { |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 108 | short file_handle; /* DOS file handle if it's a temp file */ |
| 109 | XMSH xms_handle; /* handle if it's a chunk of XMS */ |
| 110 | EMSH ems_handle; /* handle if it's a chunk of EMS */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 111 | } handle_union; |
| 112 | |
| 113 | #endif /* USE_MSDOS_MEMMGR */ |
| 114 | |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 115 | #ifdef USE_MAC_MEMMGR /* Mac-specific junk */ |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 116 | #include <Files.h> |
| 117 | #endif /* USE_MAC_MEMMGR */ |
| 118 | |
| 119 | |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 120 | typedef struct backing_store_struct * backing_store_ptr; |
| 121 | |
| 122 | typedef struct backing_store_struct { |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 123 | /* Methods for reading/writing/closing this backing-store object */ |
DRC | bc56b75 | 2014-05-16 10:43:44 +0000 | [diff] [blame] | 124 | void (*read_backing_store) (j_common_ptr cinfo, backing_store_ptr info, |
DRC | 5033f3e | 2014-05-18 18:33:44 +0000 | [diff] [blame] | 125 | void * buffer_address, long file_offset, |
DRC | bc56b75 | 2014-05-16 10:43:44 +0000 | [diff] [blame] | 126 | long byte_count); |
| 127 | void (*write_backing_store) (j_common_ptr cinfo, backing_store_ptr info, |
DRC | 5033f3e | 2014-05-18 18:33:44 +0000 | [diff] [blame] | 128 | void * buffer_address, long file_offset, |
DRC | bc56b75 | 2014-05-16 10:43:44 +0000 | [diff] [blame] | 129 | long byte_count); |
| 130 | void (*close_backing_store) (j_common_ptr cinfo, backing_store_ptr info); |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 131 | |
| 132 | /* Private fields for system-dependent backing-store management */ |
| 133 | #ifdef USE_MSDOS_MEMMGR |
| 134 | /* For the MS-DOS manager (jmemdos.c), we need: */ |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 135 | handle_union handle; /* reference to backing-store storage object */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 136 | char temp_name[TEMP_NAME_LENGTH]; /* name if it's a file */ |
| 137 | #else |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 138 | #ifdef USE_MAC_MEMMGR |
| 139 | /* For the Mac manager (jmemmac.c), we need: */ |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 140 | short temp_file; /* file reference number to temp file */ |
| 141 | FSSpec tempSpec; /* the FSSpec for the temp file */ |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 142 | char temp_name[TEMP_NAME_LENGTH]; /* name if it's a file */ |
| 143 | #else |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 144 | /* For a typical implementation with temp files, we need: */ |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 145 | FILE * temp_file; /* stdio reference to temp file */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 146 | char temp_name[TEMP_NAME_LENGTH]; /* name of temp file */ |
| 147 | #endif |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 148 | #endif |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 149 | } backing_store_info; |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 150 | |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 151 | |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 152 | /* |
| 153 | * Initial opening of a backing-store object. This must fill in the |
| 154 | * read/write/close pointers in the object. The read/write routines |
| 155 | * may take an error exit if the specified maximum file size is exceeded. |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 156 | * (If jpeg_mem_available always returns a large value, this routine can |
| 157 | * just take an error exit.) |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 158 | */ |
| 159 | |
DRC | bc56b75 | 2014-05-16 10:43:44 +0000 | [diff] [blame] | 160 | EXTERN(void) jpeg_open_backing_store (j_common_ptr cinfo, |
| 161 | backing_store_ptr info, |
| 162 | long total_bytes_needed); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 163 | |
| 164 | |
| 165 | /* |
| 166 | * These routines take care of any system-dependent initialization and |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 167 | * cleanup required. jpeg_mem_init will be called before anything is |
| 168 | * allocated (and, therefore, nothing in cinfo is of use except the error |
| 169 | * manager pointer). It should return a suitable default value for |
| 170 | * max_memory_to_use; this may subsequently be overridden by the surrounding |
| 171 | * application. (Note that max_memory_to_use is only important if |
| 172 | * jpeg_mem_available chooses to consult it ... no one else will.) |
| 173 | * jpeg_mem_term may assume that all requested memory has been freed and that |
| 174 | * all opened backing-store objects have been closed. |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 175 | */ |
| 176 | |
DRC | bc56b75 | 2014-05-16 10:43:44 +0000 | [diff] [blame] | 177 | EXTERN(long) jpeg_mem_init (j_common_ptr cinfo); |
| 178 | EXTERN(void) jpeg_mem_term (j_common_ptr cinfo); |