ReactOS 0.4.15-dev-8241-g63935f8
jmemname.c
Go to the documentation of this file.
1/*
2 * jmemname.c
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 file provides a generic implementation of the system-dependent
9 * portion of the JPEG memory manager. This implementation assumes that
10 * you must explicitly construct a name for each temp file.
11 * Also, the problem of determining the amount of memory available
12 * is shoved onto the user.
13 */
14
15#define JPEG_INTERNALS
16#include "jinclude.h"
17#include "jpeglib.h"
18#include "jmemsys.h" /* import the system-dependent declarations */
19
20#ifndef HAVE_STDLIB_H /* <stdlib.h> should declare malloc(),free() */
21extern void * malloc JPP((size_t size));
22extern void free JPP((void *ptr));
23#endif
24
25#ifndef SEEK_SET /* pre-ANSI systems may not define this; */
26#define SEEK_SET 0 /* if not, assume 0 is correct */
27#endif
28
29#ifdef DONT_USE_B_MODE /* define mode parameters for fopen() */
30#define READ_BINARY "r"
31#define RW_BINARY "w+"
32#else
33#ifdef VMS /* VMS is very nonstandard */
34#define READ_BINARY "rb", "ctx=stm"
35#define RW_BINARY "w+b", "ctx=stm"
36#else /* standard ANSI-compliant case */
37#define READ_BINARY "rb"
38#define RW_BINARY "w+b"
39#endif
40#endif
41
42
43/*
44 * Selection of a file name for a temporary file.
45 * This is system-dependent!
46 *
47 * The code as given is suitable for most Unix systems, and it is easily
48 * modified for most non-Unix systems. Some notes:
49 * 1. The temp file is created in the directory named by TEMP_DIRECTORY.
50 * The default value is /usr/tmp, which is the conventional place for
51 * creating large temp files on Unix. On other systems you'll probably
52 * want to change the file location. You can do this by editing the
53 * #define, or (preferred) by defining TEMP_DIRECTORY in jconfig.h.
54 *
55 * 2. If you need to change the file name as well as its location,
56 * you can override the TEMP_FILE_NAME macro. (Note that this is
57 * actually a printf format string; it must contain %s and %d.)
58 * Few people should need to do this.
59 *
60 * 3. mktemp() is used to ensure that multiple processes running
61 * simultaneously won't select the same file names. If your system
62 * doesn't have mktemp(), define NO_MKTEMP to do it the hard way.
63 * (If you don't have <errno.h>, also define NO_ERRNO_H.)
64 *
65 * 4. You probably want to define NEED_SIGNAL_CATCHER so that cjpeg.c/djpeg.c
66 * will cause the temp files to be removed if you stop the program early.
67 */
68
69#ifndef TEMP_DIRECTORY /* can override from jconfig.h or Makefile */
70#define TEMP_DIRECTORY "/usr/tmp/" /* recommended setting for Unix */
71#endif
72
73static int next_file_num; /* to distinguish among several temp files */
74
75#ifdef NO_MKTEMP
76
77#ifndef TEMP_FILE_NAME /* can override from jconfig.h or Makefile */
78#define TEMP_FILE_NAME "%sJPG%03d.TMP"
79#endif
80
81#ifndef NO_ERRNO_H
82#include <errno.h> /* to define ENOENT */
83#endif
84
85/* ANSI C specifies that errno is a macro, but on older systems it's more
86 * likely to be a plain int variable. And not all versions of errno.h
87 * bother to declare it, so we have to in order to be most portable. Thus:
88 */
89#ifndef errno
90extern int errno;
91#endif
92
93
94LOCAL(void)
95select_file_name (char * fname)
96{
97 FILE * tfile;
98
99 /* Keep generating file names till we find one that's not in use */
100 for (;;) {
101 next_file_num++; /* advance counter */
103 if ((tfile = fopen(fname, READ_BINARY)) == NULL) {
104 /* fopen could have failed for a reason other than the file not
105 * being there; for example, file there but unreadable.
106 * If <errno.h> isn't available, then we cannot test the cause.
107 */
108#ifdef ENOENT
109 if (errno != ENOENT)
110 continue;
111#endif
112 break;
113 }
114 fclose(tfile); /* oops, it's there; close tfile & try again */
115 }
116}
117
118#else /* ! NO_MKTEMP */
119
120/* Note that mktemp() requires the initial filename to end in six X's */
121#ifndef TEMP_FILE_NAME /* can override from jconfig.h or Makefile */
122#define TEMP_FILE_NAME "%sJPG%dXXXXXX"
123#endif
124
125LOCAL(void)
126select_file_name (char * fname)
127{
128 next_file_num++; /* advance counter */
130 mktemp(fname); /* make sure file name is unique */
131 /* mktemp replaces the trailing XXXXXX with a unique string of characters */
132}
133
134#endif /* NO_MKTEMP */
135
136
137/*
138 * Memory allocation and freeing are controlled by the regular library
139 * routines malloc() and free().
140 */
141
142GLOBAL(void *)
144{
145 return (void *) malloc(sizeofobject);
146}
147
148GLOBAL(void)
149jpeg_free_small (j_common_ptr cinfo, void * object, size_t sizeofobject)
150{
151 free(object);
152}
153
154
155/*
156 * "Large" objects are treated the same as "small" ones.
157 * NB: although we include FAR keywords in the routine declarations,
158 * this file won't actually work in 80x86 small/medium model; at least,
159 * you probably won't be able to process useful-size images in only 64KB.
160 */
161
162GLOBAL(void FAR *)
164{
165 return (void FAR *) malloc(sizeofobject);
166}
167
168GLOBAL(void)
169jpeg_free_large (j_common_ptr cinfo, void FAR * object, size_t sizeofobject)
170{
171 free(object);
172}
173
174
175/*
176 * This routine computes the total memory space available for allocation.
177 * It's impossible to do this in a portable way; our current solution is
178 * to make the user tell us (with a default value set at compile time).
179 * If you can actually get the available space, it's a good idea to subtract
180 * a slop factor of 5% or so.
181 */
182
183#ifndef DEFAULT_MAX_MEM /* so can override from makefile */
184#define DEFAULT_MAX_MEM 1000000L /* default: one megabyte */
185#endif
186
187GLOBAL(long)
190{
191 return cinfo->mem->max_memory_to_use - already_allocated;
192}
193
194
195/*
196 * Backing store (temporary file) management.
197 * Backing store objects are only used when the value returned by
198 * jpeg_mem_available is less than the total space needed. You can dispense
199 * with these routines if you have plenty of virtual memory; see jmemnobs.c.
200 */
201
202
203METHODDEF(void)
205 void FAR * buffer_address,
206 long file_offset, long byte_count)
207{
208 if (fseek(info->temp_file, file_offset, SEEK_SET))
209 ERREXIT(cinfo, JERR_TFILE_SEEK);
210 if (JFREAD(info->temp_file, buffer_address, byte_count)
211 != (size_t) byte_count)
212 ERREXIT(cinfo, JERR_TFILE_READ);
213}
214
215
216METHODDEF(void)
218 void FAR * buffer_address,
219 long file_offset, long byte_count)
220{
221 if (fseek(info->temp_file, file_offset, SEEK_SET))
222 ERREXIT(cinfo, JERR_TFILE_SEEK);
223 if (JFWRITE(info->temp_file, buffer_address, byte_count)
224 != (size_t) byte_count)
225 ERREXIT(cinfo, JERR_TFILE_WRITE);
226}
227
228
229METHODDEF(void)
231{
232 fclose(info->temp_file); /* close the file */
233 unlink(info->temp_name); /* delete the file */
234/* If your system doesn't have unlink(), use remove() instead.
235 * remove() is the ANSI-standard name for this function, but if
236 * your system was ANSI you'd be using jmemansi.c, right?
237 */
238 TRACEMSS(cinfo, 1, JTRC_TFILE_CLOSE, info->temp_name);
239}
240
241
242/*
243 * Initial opening of a backing-store object.
244 */
245
246GLOBAL(void)
249{
250 select_file_name(info->temp_name);
251 if ((info->temp_file = fopen(info->temp_name, RW_BINARY)) == NULL)
252 ERREXITS(cinfo, JERR_TFILE_CREATE, info->temp_name);
253 info->read_backing_store = read_backing_store;
254 info->write_backing_store = write_backing_store;
255 info->close_backing_store = close_backing_store;
256 TRACEMSS(cinfo, 1, JTRC_TFILE_OPEN, info->temp_name);
257}
258
259
260/*
261 * These routines take care of any system-dependent initialization and
262 * cleanup required.
263 */
264
265GLOBAL(long)
267{
268 next_file_num = 0; /* initialize temp file name generator */
269 return DEFAULT_MAX_MEM; /* default for max_memory_to_use */
270}
271
272GLOBAL(void)
274{
275 /* no work */
276}
#define ENOENT
Definition: acclib.h:79
#define free
Definition: debug_ros.c:5
#define malloc
Definition: debug_ros.c:4
#define NULL
Definition: types.h:112
#define FAR
Definition: zlib.h:34
GLsizeiptr size
Definition: glext.h:5919
_Check_return_ _CRTIMP FILE *__cdecl fopen(_In_z_ const char *_Filename, _In_z_ const char *_Mode)
_Check_return_opt_ _CRTIMP int __cdecl fseek(_Inout_ FILE *_File, _In_ long _Offset, _In_ int _Origin)
_Check_return_opt_ _CRTIMP int __cdecl fclose(_Inout_ FILE *_File)
#define ERREXITS(cinfo, code, str)
Definition: jerror.h:243
#define TRACEMSS(cinfo, lvl, code, str)
Definition: jerror.h:299
#define JFWRITE(file, buf, sizeofbuf)
Definition: jinclude.h:94
#define JFREAD(file, buf, sizeofbuf)
Definition: jinclude.h:92
#define SEEK_SET
Definition: jmemname.c:26
select_file_name(char *fname)
Definition: jmemname.c:126
#define DEFAULT_MAX_MEM
Definition: jmemname.c:184
#define TEMP_DIRECTORY
Definition: jmemname.c:70
static int next_file_num
Definition: jmemname.c:73
write_backing_store(j_common_ptr cinfo, backing_store_ptr info, void FAR *buffer_address, long file_offset, long byte_count)
Definition: jmemname.c:217
jpeg_free_large(j_common_ptr cinfo, void FAR *object, size_t sizeofobject)
Definition: jmemname.c:169
jpeg_get_large(j_common_ptr cinfo, size_t sizeofobject)
Definition: jmemname.c:163
jpeg_free_small(j_common_ptr cinfo, void *object, size_t sizeofobject)
Definition: jmemname.c:149
close_backing_store(j_common_ptr cinfo, backing_store_ptr info)
Definition: jmemname.c:230
#define READ_BINARY
Definition: jmemname.c:37
jpeg_get_small(j_common_ptr cinfo, size_t sizeofobject)
Definition: jmemname.c:143
#define TEMP_FILE_NAME
Definition: jmemname.c:122
jpeg_mem_term(j_common_ptr cinfo)
Definition: jmemname.c:273
read_backing_store(j_common_ptr cinfo, backing_store_ptr info, void FAR *buffer_address, long file_offset, long byte_count)
Definition: jmemname.c:204
jpeg_open_backing_store(j_common_ptr cinfo, backing_store_ptr info, long total_bytes_needed)
Definition: jmemname.c:247
jpeg_mem_available(j_common_ptr cinfo, long min_bytes_needed, long max_bytes_needed, long already_allocated)
Definition: jmemname.c:188
#define RW_BINARY
Definition: jmemname.c:38
jpeg_mem_init(j_common_ptr cinfo)
Definition: jmemname.c:266
long long max_bytes_needed
Definition: jmemsys.h:105
size_t sizeofobject
Definition: jmemsys.h:47
long min_bytes_needed
Definition: jmemsys.h:104
long long long already_allocated
Definition: jmemsys.h:106
backing_store_ptr long total_bytes_needed
Definition: jmemsys.h:182
#define LOCAL(type)
Definition: jmorecfg.h:289
#define METHODDEF(type)
Definition: jmorecfg.h:287
#define GLOBAL(type)
Definition: jmorecfg.h:291
#define JPP(arglist)
Definition: jpeglib.h:877
#define unlink
Definition: syshdrs.h:54
static PVOID ptr
Definition: dispmode.c:27
#define sprintf(buf, format,...)
Definition: sprintf.c:55
#define ERREXIT(msg)
Definition: rdjpgcom.c:72
#define errno
Definition: errno.h:18
_CRTIMP char *__cdecl mktemp(_Inout_z_ char *_TemplateName)