openshot-audio  0.1.6
jmemsys.h
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1 /*
2  * jmemsys.h
3  *
4  * Copyright (C) 1992-1997, Thomas G. Lane.
5  * This file is part of the Independent JPEG Group's software.
6  * For conditions of distribution and use, see the accompanying README file.
7  *
8  * This include file defines the interface between the system-independent
9  * and system-dependent portions of the JPEG memory manager. No other
10  * modules need include it. (The system-independent portion is jmemmgr.c;
11  * there are several different versions of the system-dependent portion.)
12  *
13  * This file works as-is for the system-dependent memory managers supplied
14  * in the IJG distribution. You may need to modify it if you write a
15  * custom memory manager. If system-dependent changes are needed in
16  * this file, the best method is to #ifdef them based on a configuration
17  * symbol supplied in jconfig.h, as we have done with USE_MSDOS_MEMMGR
18  * and USE_MAC_MEMMGR.
19  */
20 
21 #ifndef __jmemsys_h__
22 #define __jmemsys_h__
23 
24 /* Short forms of external names for systems with brain-damaged linkers. */
25 
26 #ifdef NEED_SHORT_EXTERNAL_NAMES
27 #define jpeg_get_small jGetSmall
28 #define jpeg_free_small jFreeSmall
29 #define jpeg_get_large jGetLarge
30 #define jpeg_free_large jFreeLarge
31 #define jpeg_mem_available jMemAvail
32 #define jpeg_open_backing_store jOpenBackStore
33 #define jpeg_mem_init jMemInit
34 #define jpeg_mem_term jMemTerm
35 #endif /* NEED_SHORT_EXTERNAL_NAMES */
36 
37 
38 /*
39  * These two functions are used to allocate and release small chunks of
40  * memory. (Typically the total amount requested through jpeg_get_small is
41  * no more than 20K or so; this will be requested in chunks of a few K each.)
42  * Behavior should be the same as for the standard library functions malloc
43  * and free; in particular, jpeg_get_small must return NULL on failure.
44  * On most systems, these ARE malloc and free. jpeg_free_small is passed the
45  * size of the object being freed, just in case it's needed.
46  * On an 80x86 machine using small-data memory model, these manage near heap.
47  */
48 
50 EXTERN(void) jpeg_free_small JPP((j_common_ptr cinfo, void * object,
51  size_t sizeofobject));
52 
53 /*
54  * These two functions are used to allocate and release large chunks of
55  * memory (up to the total free space designated by jpeg_mem_available).
56  * The interface is the same as above, except that on an 80x86 machine,
57  * far pointers are used. On most other machines these are identical to
58  * the jpeg_get/free_small routines; but we keep them separate anyway,
59  * in case a different allocation strategy is desirable for large chunks.
60  */
61 
63  size_t sizeofobject));
64 EXTERN(void) jpeg_free_large JPP((j_common_ptr cinfo, void FAR * object,
65  size_t sizeofobject));
66 
67 /*
68  * The macro MAX_ALLOC_CHUNK designates the maximum number of bytes that may
69  * be requested in a single call to jpeg_get_large (and jpeg_get_small for that
70  * matter, but that case should never come into play). This macro is needed
71  * to model the 64Kb-segment-size limit of far addressing on 80x86 machines.
72  * On those machines, we expect that jconfig.h will provide a proper value.
73  * On machines with 32-bit flat address spaces, any large constant may be used.
74  *
75  * NB: jmemmgr.c expects that MAX_ALLOC_CHUNK will be representable as type
76  * size_t and will be a multiple of sizeof(align_type).
77  */
78 
79 #ifndef MAX_ALLOC_CHUNK /* may be overridden in jconfig.h */
80 #define MAX_ALLOC_CHUNK 1000000000L
81 #endif
82 
83 /*
84  * This routine computes the total space still available for allocation by
85  * jpeg_get_large. If more space than this is needed, backing store will be
86  * used. NOTE: any memory already allocated must not be counted.
87  *
88  * There is a minimum space requirement, corresponding to the minimum
89  * feasible buffer sizes; jmemmgr.c will request that much space even if
90  * jpeg_mem_available returns zero. The maximum space needed, enough to hold
91  * all working storage in memory, is also passed in case it is useful.
92  * Finally, the total space already allocated is passed. If no better
93  * method is available, cinfo->mem->max_memory_to_use - already_allocated
94  * is often a suitable calculation.
95  *
96  * It is OK for jpeg_mem_available to underestimate the space available
97  * (that'll just lead to more backing-store access than is really necessary).
98  * However, an overestimate will lead to failure. Hence it's wise to subtract
99  * a slop factor from the true available space. 5% should be enough.
100  *
101  * On machines with lots of virtual memory, any large constant may be returned.
102  * Conversely, zero may be returned to always use the minimum amount of memory.
103  */
104 
107  long max_bytes_needed,
108  long already_allocated));
109 
110 
111 /*
112  * This structure holds whatever state is needed to access a single
113  * backing-store object. The read/write/close method pointers are called
114  * by jmemmgr.c to manipulate the backing-store object; all other fields
115  * are private to the system-dependent backing store routines.
116  */
117 
118 #define TEMP_NAME_LENGTH 64 /* max length of a temporary file's name */
119 
120 
121 #ifdef USE_MSDOS_MEMMGR /* DOS-specific junk */
122 
123 typedef unsigned short XMSH; /* type of extended-memory handles */
124 typedef unsigned short EMSH; /* type of expanded-memory handles */
125 
126 typedef union {
127  short file_handle; /* DOS file handle if it's a temp file */
128  XMSH xms_handle; /* handle if it's a chunk of XMS */
129  EMSH ems_handle; /* handle if it's a chunk of EMS */
130 } handle_union;
131 
132 #endif /* USE_MSDOS_MEMMGR */
133 
134 #ifdef USE_MAC_MEMMGR /* Mac-specific junk */
135 #include <Files.h>
136 #endif /* USE_MAC_MEMMGR */
137 
138 
139 //typedef struct backing_store_struct * backing_store_ptr;
140 
141 typedef struct backing_store_struct {
142  /* Methods for reading/writing/closing this backing-store object */
143  JMETHOD(void, read_backing_store, (j_common_ptr cinfo,
144  struct backing_store_struct *info,
145  void FAR * buffer_address,
146  long file_offset, long byte_count));
147  JMETHOD(void, write_backing_store, (j_common_ptr cinfo,
148  struct backing_store_struct *info,
149  void FAR * buffer_address,
150  long file_offset, long byte_count));
151  JMETHOD(void, close_backing_store, (j_common_ptr cinfo,
152  struct backing_store_struct *info));
153 
154  /* Private fields for system-dependent backing-store management */
155 #ifdef USE_MSDOS_MEMMGR
156  /* For the MS-DOS manager (jmemdos.c), we need: */
157  handle_union handle; /* reference to backing-store storage object */
158  char temp_name[TEMP_NAME_LENGTH]; /* name if it's a file */
159 #else
160 #ifdef USE_MAC_MEMMGR
161  /* For the Mac manager (jmemmac.c), we need: */
162  short temp_file; /* file reference number to temp file */
163  FSSpec tempSpec; /* the FSSpec for the temp file */
164  char temp_name[TEMP_NAME_LENGTH]; /* name if it's a file */
165 #else
166  /* For a typical implementation with temp files, we need: */
167  FILE * temp_file; /* stdio reference to temp file */
168  char temp_name[TEMP_NAME_LENGTH]; /* name of temp file */
169 #endif
170 #endif
172 
173 
174 /*
175  * Initial opening of a backing-store object. This must fill in the
176  * read/write/close pointers in the object. The read/write routines
177  * may take an error exit if the specified maximum file size is exceeded.
178  * (If jpeg_mem_available always returns a large value, this routine can
179  * just take an error exit.)
180  */
181 
184  long total_bytes_needed));
185 
186 
187 /*
188  * These routines take care of any system-dependent initialization and
189  * cleanup required. jpeg_mem_init will be called before anything is
190  * allocated (and, therefore, nothing in cinfo is of use except the error
191  * manager pointer). It should return a suitable default value for
192  * max_memory_to_use; this may subsequently be overridden by the surrounding
193  * application. (Note that max_memory_to_use is only important if
194  * jpeg_mem_available chooses to consult it ... no one else will.)
195  * jpeg_mem_term may assume that all requested memory has been freed and that
196  * all opened backing-store objects have been closed.
197  */
198 
199 EXTERN(long) jpeg_mem_init JPP((j_common_ptr cinfo));
200 EXTERN(void) jpeg_mem_term JPP((j_common_ptr cinfo));
201 
202 
203 #endif
jpeg_mem_init(j_common_ptr)
Definition: jmemnobs.c:100
char temp_name[TEMP_NAME_LENGTH]
Definition: jmemsys.h:168
FILE * temp_file
Definition: jmemsys.h:167
struct backing_store_struct * info
Definition: jmemsys.h:183
long long max_bytes_needed
Definition: jmemsys.h:106
EXTERN(void *) jpeg_get_small JPP((j_common_ptr cinfo
jpeg_free_large(j_common_ptr, void FAR *object, size_t)
Definition: jmemnobs.c:61
Definition: jpeglib.h:253
#define FAR
size_t sizeofobject
Definition: jmemsys.h:49
struct backing_store_struct long total_bytes_needed
Definition: jmemsys.h:183
struct backing_store_struct backing_store_info
jpeg_mem_term(j_common_ptr)
Definition: jmemnobs.c:106
long min_bytes_needed
Definition: jmemsys.h:106
#define TEMP_NAME_LENGTH
Definition: juce_JPEGLoader.cpp:119
#define JPP(arglist)
Definition: juce_JPEGLoader.cpp:818
long long long already_allocated
Definition: jmemsys.h:106
jpeg_free_small(j_common_ptr, void *object, size_t)
Definition: jmemnobs.c:41
jpeg_get_large(j_common_ptr, size_t sizeofobject)
Definition: jmemnobs.c:55
JMETHOD(void, read_backing_store,(j_common_ptr cinfo, struct backing_store_struct *info, void FAR *buffer_address, long file_offset, long byte_count))
jpeg_get_small(j_common_ptr, size_t sizeofobject)
Definition: jmemnobs.c:35
jpeg_mem_available(j_common_ptr, long, long max_bytes_needed, long)
Definition: jmemnobs.c:73
jpeg_open_backing_store(j_common_ptr cinfo, struct backing_store_struct *, long)
Definition: jmemnobs.c:87
Definition: jmemsys.h:141