1 /* exif-content.c
2 *
3 * Copyright (c) 2001 Lutz Mueller <lutz@users.sourceforge.net>
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
18 * Boston, MA 02110-1301 USA.
19 */
20
21 #include <config.h>
22
23 #include <libexif/exif-content.h>
24 #include <libexif/exif-system.h>
25
26 #include <stdlib.h>
27 #include <stdio.h>
28 #include <string.h>
29
30 /* unused constant
31 * static const unsigned char ExifHeader[] = {0x45, 0x78, 0x69, 0x66, 0x00, 0x00};
32 */
33
34 struct _ExifContentPrivate
35 {
36 unsigned int ref_count;
37
38 ExifMem *mem;
39 ExifLog *log;
40 };
41
42 ExifContent *
exif_content_new(void)43 exif_content_new (void)
44 {
45 ExifMem *mem = exif_mem_new_default ();
46 ExifContent *content = exif_content_new_mem (mem);
47
48 exif_mem_unref (mem);
49
50 return content;
51 }
52
53 ExifContent *
exif_content_new_mem(ExifMem * mem)54 exif_content_new_mem (ExifMem *mem)
55 {
56 ExifContent *content;
57
58 if (!mem) return NULL;
59
60 content = exif_mem_alloc (mem, (ExifLong) sizeof (ExifContent));
61 if (!content)
62 return NULL;
63 content->priv = exif_mem_alloc (mem,
64 (ExifLong) sizeof (ExifContentPrivate));
65 if (!content->priv) {
66 exif_mem_free (mem, content);
67 return NULL;
68 }
69
70 content->priv->ref_count = 1;
71
72 content->priv->mem = mem;
73 exif_mem_ref (mem);
74
75 return content;
76 }
77
78 void
exif_content_ref(ExifContent * content)79 exif_content_ref (ExifContent *content)
80 {
81 if (!content)
82 return;
83
84 content->priv->ref_count++;
85 }
86
87 void
exif_content_unref(ExifContent * content)88 exif_content_unref (ExifContent *content)
89 {
90 if (!content)
91 return;
92
93 content->priv->ref_count--;
94 if (!content->priv->ref_count)
95 exif_content_free (content);
96 }
97
98 void
exif_content_free(ExifContent * content)99 exif_content_free (ExifContent *content)
100 {
101 ExifMem *mem = (content && content->priv) ? content->priv->mem : NULL;
102 unsigned int i;
103
104 if (!content) return;
105
106 for (i = 0; i < content->count; i++)
107 exif_entry_unref (content->entries[i]);
108 exif_mem_free (mem, content->entries);
109
110 if (content->priv) {
111 exif_log_unref (content->priv->log);
112 }
113
114 exif_mem_free (mem, content->priv);
115 exif_mem_free (mem, content);
116 exif_mem_unref (mem);
117 }
118
119 void
exif_content_dump(ExifContent * content,unsigned int indent)120 exif_content_dump (ExifContent *content, unsigned int indent)
121 {
122 char buf[1024];
123 unsigned int i, l;
124
125 if (!content)
126 return;
127
128 l = MIN(sizeof(buf)-1, 2*indent);
129 memset(buf, ' ', l);
130 buf[l] = '\0';
131
132 printf ("%sDumping exif content (%u entries)...\n", buf,
133 content->count);
134 for (i = 0; i < content->count; i++)
135 exif_entry_dump (content->entries[i], indent + 1);
136 }
137
138 void
exif_content_add_entry(ExifContent * c,ExifEntry * entry)139 exif_content_add_entry (ExifContent *c, ExifEntry *entry)
140 {
141 ExifEntry **entries;
142 if (!c || !c->priv || !entry || entry->parent) return;
143
144 /* One tag can only be added once to an IFD. */
145 if (exif_content_get_entry (c, entry->tag)) {
146 exif_log (c->priv->log, EXIF_LOG_CODE_DEBUG, "ExifContent",
147 "An attempt has been made to add "
148 "the tag '%s' twice to an IFD. This is against "
149 "specification.", exif_tag_get_name (entry->tag));
150 return;
151 }
152
153 entries = exif_mem_realloc (c->priv->mem,
154 c->entries, sizeof (ExifEntry*) * (c->count + 1));
155 if (!entries) return;
156 entry->parent = c;
157 entries[c->count++] = entry;
158 c->entries = entries;
159 exif_entry_ref (entry);
160 }
161
162 void
exif_content_remove_entry(ExifContent * c,ExifEntry * e)163 exif_content_remove_entry (ExifContent *c, ExifEntry *e)
164 {
165 unsigned int i;
166 ExifEntry **t, *temp;
167
168 if (!c || !c->priv || !e || (e->parent != c)) return;
169
170 /* Search the entry */
171 for (i = 0; i < c->count; i++)
172 if (c->entries[i] == e)
173 break;
174
175 if (i == c->count)
176 return;
177
178 /* Remove the entry */
179 temp = c->entries[c->count-1];
180 if (c->count > 1) {
181 t = exif_mem_realloc (c->priv->mem, c->entries,
182 sizeof(ExifEntry*) * (c->count - 1));
183 if (!t) {
184 return;
185 }
186 c->entries = t;
187 c->count--;
188 if (i != c->count) { /* we deallocated the last slot already */
189 memmove (&t[i], &t[i + 1], sizeof (ExifEntry*) * (c->count - i - 1));
190 t[c->count-1] = temp;
191 }
192 } else {
193 exif_mem_free (c->priv->mem, c->entries);
194 c->entries = NULL;
195 c->count = 0;
196 }
197 e->parent = NULL;
198 exif_entry_unref (e);
199 }
200
201 ExifEntry *
exif_content_get_entry(ExifContent * content,ExifTag tag)202 exif_content_get_entry (ExifContent *content, ExifTag tag)
203 {
204 unsigned int i;
205
206 if (!content)
207 return (NULL);
208
209 for (i = 0; i < content->count; i++)
210 if (content->entries[i]->tag == tag)
211 return (content->entries[i]);
212 return (NULL);
213 }
214
215 void
exif_content_foreach_entry(ExifContent * content,ExifContentForeachEntryFunc func,void * data)216 exif_content_foreach_entry (ExifContent *content,
217 ExifContentForeachEntryFunc func, void *data)
218 {
219 unsigned int i;
220
221 if (!content || !func)
222 return;
223
224 for (i = 0; i < content->count; i++)
225 func (content->entries[i], data);
226 }
227
228 void
exif_content_log(ExifContent * content,ExifLog * log)229 exif_content_log (ExifContent *content, ExifLog *log)
230 {
231 if (!content || !content->priv || !log || content->priv->log == log)
232 return;
233
234 if (content->priv->log) exif_log_unref (content->priv->log);
235 content->priv->log = log;
236 exif_log_ref (log);
237 }
238
239 ExifIfd
exif_content_get_ifd(ExifContent * c)240 exif_content_get_ifd (ExifContent *c)
241 {
242 if (!c || !c->parent) return EXIF_IFD_COUNT;
243
244 return
245 ((c)->parent->ifd[EXIF_IFD_EXIF] == (c)) ? EXIF_IFD_EXIF :
246 ((c)->parent->ifd[EXIF_IFD_0] == (c)) ? EXIF_IFD_0 :
247 ((c)->parent->ifd[EXIF_IFD_1] == (c)) ? EXIF_IFD_1 :
248 ((c)->parent->ifd[EXIF_IFD_GPS] == (c)) ? EXIF_IFD_GPS :
249 ((c)->parent->ifd[EXIF_IFD_INTEROPERABILITY] == (c)) ? EXIF_IFD_INTEROPERABILITY :
250 EXIF_IFD_COUNT;
251 }
252
253 static void
fix_func(ExifEntry * e,void * UNUSED (data))254 fix_func (ExifEntry *e, void *UNUSED(data))
255 {
256 exif_entry_fix (e);
257 }
258
259 /*!
260 * Check if this entry is unknown and if so, delete it.
261 * \note Be careful calling this function in a loop. Deleting an entry from
262 * an ExifContent changes the index of subsequent entries, as well as the
263 * total size of the entries array.
264 */
265 static void
remove_not_recorded(ExifEntry * e,void * UNUSED (data))266 remove_not_recorded (ExifEntry *e, void *UNUSED(data))
267 {
268 ExifIfd ifd = exif_entry_get_ifd(e) ;
269 ExifContent *c = e->parent;
270 ExifDataType dt = exif_data_get_data_type (c->parent);
271 ExifTag t = e->tag;
272
273 if (exif_tag_get_support_level_in_ifd (t, ifd, dt) ==
274 EXIF_SUPPORT_LEVEL_NOT_RECORDED) {
275 exif_log (c->priv->log, EXIF_LOG_CODE_DEBUG, "exif-content",
276 "Tag 0x%04x is not recorded in IFD '%s' and has therefore been "
277 "removed.", t, exif_ifd_get_name (ifd));
278 exif_content_remove_entry (c, e);
279 }
280
281 }
282
283 void
exif_content_fix(ExifContent * c)284 exif_content_fix (ExifContent *c)
285 {
286 ExifIfd ifd = exif_content_get_ifd (c);
287 ExifDataType dt;
288 ExifEntry *e;
289 unsigned int i, num;
290
291 if (!c)
292 return;
293
294 dt = exif_data_get_data_type (c->parent);
295
296 /*
297 * First of all, fix all existing entries.
298 */
299 exif_content_foreach_entry (c, fix_func, NULL);
300
301 /*
302 * Go through each tag and if it's not recorded, remove it. If one
303 * is removed, exif_content_foreach_entry() will skip the next entry,
304 * so if this happens do the loop again from the beginning to ensure
305 * they're all checked. This could be avoided if we stop relying on
306 * exif_content_foreach_entry but loop intelligently here.
307 */
308 do {
309 num = c->count;
310 exif_content_foreach_entry (c, remove_not_recorded, NULL);
311 } while (num != c->count);
312
313 /*
314 * Then check for non-existing mandatory tags and create them if needed
315 */
316 num = exif_tag_table_count();
317 for (i = 0; i < num; ++i) {
318 const ExifTag t = exif_tag_table_get_tag (i);
319 if (exif_tag_get_support_level_in_ifd (t, ifd, dt) ==
320 EXIF_SUPPORT_LEVEL_MANDATORY) {
321 if (exif_content_get_entry (c, t))
322 /* This tag already exists */
323 continue;
324 exif_log (c->priv->log, EXIF_LOG_CODE_DEBUG, "exif-content",
325 "Tag '%s' is mandatory in IFD '%s' and has therefore been added.",
326 exif_tag_get_name_in_ifd (t, ifd), exif_ifd_get_name (ifd));
327 e = exif_entry_new ();
328 exif_content_add_entry (c, e);
329 exif_entry_initialize (e, t);
330 exif_entry_unref (e);
331 }
332 }
333 }
334