source: rtems-graphics-toolkit/jpeg-8d/jmemname.c @ 86b99f7

Last change on this file since 86b99f7 was 86b99f7, checked in by Alexandru-Sever Horin <alex.sever.h@…>, on Aug 1, 2012 at 10:40:32 PM

Added jpeg-8d version. Made modifications to compile for RTEMS, without man or binaries

  • Property mode set to 100644
File size: 8.1 KB
Line 
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 */
102    sprintf(fname, TEMP_FILE_NAME, TEMP_DIRECTORY, next_file_num);
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 */
129  sprintf(fname, TEMP_FILE_NAME, TEMP_DIRECTORY, next_file_num);
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 *)
143jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject)
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 *)
163jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject)
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)
188jpeg_mem_available (j_common_ptr cinfo, long min_bytes_needed,
189                    long max_bytes_needed, long already_allocated)
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)
204read_backing_store (j_common_ptr cinfo, backing_store_ptr info,
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)
217write_backing_store (j_common_ptr cinfo, backing_store_ptr info,
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)
230close_backing_store (j_common_ptr cinfo, backing_store_ptr info)
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)
247jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info,
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
265GLOBAL(long)
266jpeg_mem_init (j_common_ptr cinfo)
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)
273jpeg_mem_term (j_common_ptr cinfo)
274{
275  /* no work */
276}
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