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jmemname.c
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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() */
21 extern void * malloc JPP((size_t size));
22 extern 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 
73 static 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
90 extern int errno;
91 #endif
92 
93 
94 LOCAL(void)
95 select_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 
125 LOCAL(void)
126 select_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 
142 GLOBAL(void *)
144 {
145  return (void *) malloc(sizeofobject);
146 }
147 
148 GLOBAL(void)
149 jpeg_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 
162 GLOBAL(void FAR *)
164 {
165  return (void FAR *) malloc(sizeofobject);
166 }
167 
168 GLOBAL(void)
169 jpeg_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 
187 GLOBAL(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 
203 METHODDEF(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 
216 METHODDEF(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 
229 METHODDEF(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 
246 GLOBAL(void)
248  long total_bytes_needed)
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 
265 GLOBAL(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 
272 GLOBAL(void)
274 {
275  /* no work */
276 }
#define RW_BINARY
Definition: jmemname.c:38
select_file_name(char *fname)
Definition: jmemname.c:126
jpeg_mem_init(j_common_ptr cinfo)
Definition: jmemname.c:266
jpeg_free_small(j_common_ptr cinfo, void *object, size_t sizeofobject)
Definition: jmemname.c:149
#define ERREXIT(msg)
Definition: rdjpgcom.c:72
#define TEMP_DIRECTORY
Definition: jmemname.c:70
#define READ_BINARY
Definition: jmemname.c:37
long long max_bytes_needed
Definition: jmemsys.h:104
#define free
Definition: debug_ros.c:5
jpeg_get_small(j_common_ptr cinfo, size_t sizeofobject)
Definition: jmemname.c:143
jpeg_mem_term(j_common_ptr cinfo)
Definition: jmemname.c:273
#define unlink
Definition: syshdrs.h:54
jpeg_open_backing_store(j_common_ptr cinfo, backing_store_ptr info, long total_bytes_needed)
Definition: jmemname.c:247
jpeg_free_large(j_common_ptr cinfo, void FAR *object, size_t sizeofobject)
Definition: jmemname.c:169
int errno
#define JFREAD(file, buf, sizeofbuf)
Definition: jinclude.h:92
#define JFWRITE(file, buf, sizeofbuf)
Definition: jinclude.h:94
size_t sizeofobject
Definition: jmemsys.h:47
#define sprintf(buf, format,...)
Definition: sprintf.c:55
#define SEEK_SET
Definition: jmemname.c:26
#define FAR
Definition: guiddef.h:36
static PVOID ptr
Definition: dispmode.c:27
smooth NULL
Definition: ftsmooth.c:416
_Check_return_opt_ _CRTIMP int __cdecl fseek(_Inout_ FILE *_File, _In_ long _Offset, _In_ int _Origin)
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
backing_store_ptr long total_bytes_needed
Definition: jmemsys.h:181
#define LOCAL(type)
Definition: jmorecfg.h:289
#define TRACEMSS(cinfo, lvl, code, str)
Definition: jerror.h:299
GLsizeiptr size
Definition: glext.h:5919
long min_bytes_needed
Definition: jmemsys.h:104
_CRTIMP char *__cdecl mktemp(_Inout_z_ char *_TemplateName)
jpeg_get_large(j_common_ptr cinfo, size_t sizeofobject)
Definition: jmemname.c:163
long long long already_allocated
Definition: jmemsys.h:104
_Check_return_opt_ _CRTIMP int __cdecl fclose(_Inout_ FILE *_File)
_Check_return_ _CRTIMP FILE *__cdecl fopen(_In_z_ const char *_Filename, _In_z_ const char *_Mode)
#define GLOBAL(type)
Definition: jmorecfg.h:291
#define METHODDEF(type)
Definition: jmorecfg.h:287
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
Definition: arc.h:46
#define DEFAULT_MAX_MEM
Definition: jmemname.c:184
#define malloc
Definition: debug_ros.c:4
void *malloc JPP((size_t size))
#define TEMP_FILE_NAME
Definition: jmemname.c:122
jpeg_mem_available(j_common_ptr cinfo, long min_bytes_needed, long max_bytes_needed, long already_allocated)
Definition: jmemname.c:188
close_backing_store(j_common_ptr cinfo, backing_store_ptr info)
Definition: jmemname.c:230
#define ERREXITS(cinfo, code, str)
Definition: jerror.h:243
static int next_file_num
Definition: jmemname.c:73