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comparison mupdf-source/thirdparty/libjpeg/jmemmac.c @ 2:b50eed0cc0ef upstream

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ADD: MuPDF v1.26.7: the MuPDF source as downloaded by a default build of PyMuPDF 1.26.4. The directory name has changed: no version number in the expanded directory now.
author Franz Glasner <fzglas.hg@dom66.de>
date Mon, 15 Sep 2025 11:43:07 +0200
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1 /*
2 * jmemmac.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 * jmemmac.c provides an Apple Macintosh implementation of the system-
9 * dependent portion of the JPEG memory manager.
10 *
11 * If you use jmemmac.c, then you must define USE_MAC_MEMMGR in the
12 * JPEG_INTERNALS part of jconfig.h.
13 *
14 * jmemmac.c uses the Macintosh toolbox routines NewPtr and DisposePtr
15 * instead of malloc and free. It accurately determines the amount of
16 * memory available by using CompactMem. Notice that if left to its
17 * own devices, this code can chew up all available space in the
18 * application's zone, with the exception of the rather small "slop"
19 * factor computed in jpeg_mem_available(). The application can ensure
20 * that more space is left over by reducing max_memory_to_use.
21 *
22 * Large images are swapped to disk using temporary files and System 7.0+'s
23 * temporary folder functionality.
24 *
25 * Note that jmemmac.c depends on two features of MacOS that were first
26 * introduced in System 7: FindFolder and the FSSpec-based calls.
27 * If your application uses jmemmac.c and is run under System 6 or earlier,
28 * and the jpeg library decides it needs a temporary file, it will abort,
29 * printing error messages about requiring System 7. (If no temporary files
30 * are created, it will run fine.)
31 *
32 * If you want to use jmemmac.c in an application that might be used with
33 * System 6 or earlier, then you should remove dependencies on FindFolder
34 * and the FSSpec calls. You will need to replace FindFolder with some
35 * other mechanism for finding a place to put temporary files, and you
36 * should replace the FSSpec calls with their HFS equivalents:
37 *
38 * FSpDelete -> HDelete
39 * FSpGetFInfo -> HGetFInfo
40 * FSpCreate -> HCreate
41 * FSpOpenDF -> HOpen *** Note: not HOpenDF ***
42 * FSMakeFSSpec -> (fill in spec by hand.)
43 *
44 * (Use HOpen instead of HOpenDF. HOpen is just a glue-interface to PBHOpen,
45 * which is on all HFS macs. HOpenDF is a System 7 addition which avoids the
46 * ages-old problem of names starting with a period.)
47 *
48 * Contributed by Sam Bushell (jsam@iagu.on.net) and
49 * Dan Gildor (gyld@in-touch.com).
50 */
51
52 #define JPEG_INTERNALS
53 #include "jinclude.h"
54 #include "jpeglib.h"
55 #include "jmemsys.h" /* import the system-dependent declarations */
56
57 #ifndef USE_MAC_MEMMGR /* make sure user got configuration right */
58 You forgot to define USE_MAC_MEMMGR in jconfig.h. /* deliberate syntax error */
59 #endif
60
61 #include <Memory.h> /* we use the MacOS memory manager */
62 #include <Files.h> /* we use the MacOS File stuff */
63 #include <Folders.h> /* we use the MacOS HFS stuff */
64 #include <Script.h> /* for smSystemScript */
65 #include <Gestalt.h> /* we use Gestalt to test for specific functionality */
66
67 #ifndef TEMP_FILE_NAME /* can override from jconfig.h or Makefile */
68 #define TEMP_FILE_NAME "JPG%03d.TMP"
69 #endif
70
71 static int next_file_num; /* to distinguish among several temp files */
72
73
74 /*
75 * Memory allocation and freeing are controlled by the MacOS library
76 * routines NewPtr() and DisposePtr(), which allocate fixed-address
77 * storage. Unfortunately, the IJG library isn't smart enough to cope
78 * with relocatable storage.
79 */
80
81 GLOBAL(void *)
82 jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject)
83 {
84 return (void *) NewPtr(sizeofobject);
85 }
86
87 GLOBAL(void)
88 jpeg_free_small (j_common_ptr cinfo, void * object, size_t sizeofobject)
89 {
90 DisposePtr((Ptr) object);
91 }
92
93
94 /*
95 * "Large" objects are treated the same as "small" ones.
96 * NB: we include FAR keywords in the routine declarations simply for
97 * consistency with the rest of the IJG code; FAR should expand to empty
98 * on rational architectures like the Mac.
99 */
100
101 GLOBAL(void FAR *)
102 jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject)
103 {
104 return (void FAR *) NewPtr(sizeofobject);
105 }
106
107 GLOBAL(void)
108 jpeg_free_large (j_common_ptr cinfo, void FAR * object, size_t sizeofobject)
109 {
110 DisposePtr((Ptr) object);
111 }
112
113
114 /*
115 * This routine computes the total memory space available for allocation.
116 */
117
118 GLOBAL(long)
119 jpeg_mem_available (j_common_ptr cinfo, long min_bytes_needed,
120 long max_bytes_needed, long already_allocated)
121 {
122 long limit = cinfo->mem->max_memory_to_use - already_allocated;
123 long slop, mem;
124
125 /* Don't ask for more than what application has told us we may use */
126 if (max_bytes_needed > limit && limit > 0)
127 max_bytes_needed = limit;
128 /* Find whether there's a big enough free block in the heap.
129 * CompactMem tries to create a contiguous block of the requested size,
130 * and then returns the size of the largest free block (which could be
131 * much more or much less than we asked for).
132 * We add some slop to ensure we don't use up all available memory.
133 */
134 slop = max_bytes_needed / 16 + 32768L;
135 mem = CompactMem(max_bytes_needed + slop) - slop;
136 if (mem < 0)
137 mem = 0; /* sigh, couldn't even get the slop */
138 /* Don't take more than the application says we can have */
139 if (mem > limit && limit > 0)
140 mem = limit;
141 return mem;
142 }
143
144
145 /*
146 * Backing store (temporary file) management.
147 * Backing store objects are only used when the value returned by
148 * jpeg_mem_available is less than the total space needed. You can dispense
149 * with these routines if you have plenty of virtual memory; see jmemnobs.c.
150 */
151
152
153 METHODDEF(void)
154 read_backing_store (j_common_ptr cinfo, backing_store_ptr info,
155 void FAR * buffer_address,
156 long file_offset, long byte_count)
157 {
158 long bytes = byte_count;
159 long retVal;
160
161 if ( SetFPos ( info->temp_file, fsFromStart, file_offset ) != noErr )
162 ERREXIT(cinfo, JERR_TFILE_SEEK);
163
164 retVal = FSRead ( info->temp_file, &bytes,
165 (unsigned char *) buffer_address );
166 if ( retVal != noErr || bytes != byte_count )
167 ERREXIT(cinfo, JERR_TFILE_READ);
168 }
169
170
171 METHODDEF(void)
172 write_backing_store (j_common_ptr cinfo, backing_store_ptr info,
173 void FAR * buffer_address,
174 long file_offset, long byte_count)
175 {
176 long bytes = byte_count;
177 long retVal;
178
179 if ( SetFPos ( info->temp_file, fsFromStart, file_offset ) != noErr )
180 ERREXIT(cinfo, JERR_TFILE_SEEK);
181
182 retVal = FSWrite ( info->temp_file, &bytes,
183 (unsigned char *) buffer_address );
184 if ( retVal != noErr || bytes != byte_count )
185 ERREXIT(cinfo, JERR_TFILE_WRITE);
186 }
187
188
189 METHODDEF(void)
190 close_backing_store (j_common_ptr cinfo, backing_store_ptr info)
191 {
192 FSClose ( info->temp_file );
193 FSpDelete ( &(info->tempSpec) );
194 }
195
196
197 /*
198 * Initial opening of a backing-store object.
199 *
200 * This version uses FindFolder to find the Temporary Items folder,
201 * and puts the temporary file in there.
202 */
203
204 GLOBAL(void)
205 jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info,
206 long total_bytes_needed)
207 {
208 short tmpRef, vRefNum;
209 long dirID;
210 FInfo finderInfo;
211 FSSpec theSpec;
212 Str255 fName;
213 OSErr osErr;
214 long gestaltResponse = 0;
215
216 /* Check that FSSpec calls are available. */
217 osErr = Gestalt( gestaltFSAttr, &gestaltResponse );
218 if ( ( osErr != noErr )
219 || !( gestaltResponse & (1<<gestaltHasFSSpecCalls) ) )
220 ERREXITS(cinfo, JERR_TFILE_CREATE, "- System 7.0 or later required");
221 /* TO DO: add a proper error message to jerror.h. */
222
223 /* Check that FindFolder is available. */
224 osErr = Gestalt( gestaltFindFolderAttr, &gestaltResponse );
225 if ( ( osErr != noErr )
226 || !( gestaltResponse & (1<<gestaltFindFolderPresent) ) )
227 ERREXITS(cinfo, JERR_TFILE_CREATE, "- System 7.0 or later required.");
228 /* TO DO: add a proper error message to jerror.h. */
229
230 osErr = FindFolder ( kOnSystemDisk, kTemporaryFolderType, kCreateFolder,
231 &vRefNum, &dirID );
232 if ( osErr != noErr )
233 ERREXITS(cinfo, JERR_TFILE_CREATE, "- temporary items folder unavailable");
234 /* TO DO: Try putting the temp files somewhere else. */
235
236 /* Keep generating file names till we find one that's not in use */
237 for (;;) {
238 next_file_num++; /* advance counter */
239
240 sprintf(info->temp_name, TEMP_FILE_NAME, next_file_num);
241 strcpy ( (Ptr)fName+1, info->temp_name );
242 *fName = strlen (info->temp_name);
243 osErr = FSMakeFSSpec ( vRefNum, dirID, fName, &theSpec );
244
245 if ( (osErr = FSpGetFInfo ( &theSpec, &finderInfo ) ) != noErr )
246 break;
247 }
248
249 osErr = FSpCreate ( &theSpec, '????', '????', smSystemScript );
250 if ( osErr != noErr )
251 ERREXITS(cinfo, JERR_TFILE_CREATE, info->temp_name);
252
253 osErr = FSpOpenDF ( &theSpec, fsRdWrPerm, &(info->temp_file) );
254 if ( osErr != noErr )
255 ERREXITS(cinfo, JERR_TFILE_CREATE, info->temp_name);
256
257 info->tempSpec = theSpec;
258
259 info->read_backing_store = read_backing_store;
260 info->write_backing_store = write_backing_store;
261 info->close_backing_store = close_backing_store;
262 TRACEMSS(cinfo, 1, JTRC_TFILE_OPEN, info->temp_name);
263 }
264
265
266 /*
267 * These routines take care of any system-dependent initialization and
268 * cleanup required.
269 */
270
271 GLOBAL(long)
272 jpeg_mem_init (j_common_ptr cinfo)
273 {
274 next_file_num = 0;
275
276 /* max_memory_to_use will be initialized to FreeMem()'s result;
277 * the calling application might later reduce it, for example
278 * to leave room to invoke multiple JPEG objects.
279 * Note that FreeMem returns the total number of free bytes;
280 * it may not be possible to allocate a single block of this size.
281 */
282 return FreeMem();
283 }
284
285 GLOBAL(void)
286 jpeg_mem_term (j_common_ptr cinfo)
287 {
288 /* no work */
289 }