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 content->priv->ref_count++;
82 }
83
84 void
exif_content_unref(ExifContent * content)85 exif_content_unref (ExifContent *content)
86 {
87 content->priv->ref_count--;
88 if (!content->priv->ref_count)
89 exif_content_free (content);
90 }
91
92 void
exif_content_free(ExifContent * content)93 exif_content_free (ExifContent *content)
94 {
95 ExifMem *mem = (content && content->priv) ? content->priv->mem : NULL;
96 unsigned int i;
97
98 if (!content) return;
99
100 for (i = 0; i < content->count; i++)
101 exif_entry_unref (content->entries[i]);
102 exif_mem_free (mem, content->entries);
103
104 if (content->priv) {
105 exif_log_unref (content->priv->log);
106 }
107
108 exif_mem_free (mem, content->priv);
109 exif_mem_free (mem, content);
110 exif_mem_unref (mem);
111 }
112
113 void
exif_content_dump(ExifContent * content,unsigned int indent)114 exif_content_dump (ExifContent *content, unsigned int indent)
115 {
116 char buf[1024];
117 unsigned int i;
118
119 for (i = 0; i < 2 * indent; i++)
120 buf[i] = ' ';
121 buf[i] = '\0';
122
123 if (!content)
124 return;
125
126 printf ("%sDumping exif content (%u entries)...\n", buf,
127 content->count);
128 for (i = 0; i < content->count; i++)
129 exif_entry_dump (content->entries[i], indent + 1);
130 }
131
132 void
exif_content_add_entry(ExifContent * c,ExifEntry * entry)133 exif_content_add_entry (ExifContent *c, ExifEntry *entry)
134 {
135 ExifEntry **entries;
136 if (!c || !c->priv || !entry || entry->parent) return;
137
138 /* One tag can only be added once to an IFD. */
139 if (exif_content_get_entry (c, entry->tag)) {
140 exif_log (c->priv->log, EXIF_LOG_CODE_DEBUG, "ExifContent",
141 "An attempt has been made to add "
142 "the tag '%s' twice to an IFD. This is against "
143 "specification.", exif_tag_get_name (entry->tag));
144 return;
145 }
146
147 entries = exif_mem_realloc (c->priv->mem,
148 c->entries, sizeof (ExifEntry*) * (c->count + 1));
149 if (!entries) return;
150 entry->parent = c;
151 entries[c->count++] = entry;
152 c->entries = entries;
153 exif_entry_ref (entry);
154 }
155
156 void
exif_content_remove_entry(ExifContent * c,ExifEntry * e)157 exif_content_remove_entry (ExifContent *c, ExifEntry *e)
158 {
159 unsigned int i;
160 ExifEntry **t, *temp;
161
162 if (!c || !c->priv || !e || (e->parent != c)) return;
163
164 /* Search the entry */
165 for (i = 0; i < c->count; i++)
166 if (c->entries[i] == e)
167 break;
168
169 if (i == c->count)
170 return;
171
172 /* Remove the entry */
173 temp = c->entries[c->count-1];
174 if (c->count > 1) {
175 t = exif_mem_realloc (c->priv->mem, c->entries,
176 sizeof(ExifEntry*) * (c->count - 1));
177 if (!t) {
178 return;
179 }
180 c->entries = t;
181 c->count--;
182 if (i != c->count) { /* we deallocated the last slot already */
183 memmove (&t[i], &t[i + 1], sizeof (ExifEntry*) * (c->count - i - 1));
184 t[c->count-1] = temp;
185 }
186 } else {
187 exif_mem_free (c->priv->mem, c->entries);
188 c->entries = NULL;
189 c->count = 0;
190 }
191 e->parent = NULL;
192 exif_entry_unref (e);
193 }
194
195 ExifEntry *
exif_content_get_entry(ExifContent * content,ExifTag tag)196 exif_content_get_entry (ExifContent *content, ExifTag tag)
197 {
198 unsigned int i;
199
200 if (!content)
201 return (NULL);
202
203 for (i = 0; i < content->count; i++)
204 if (content->entries[i]->tag == tag)
205 return (content->entries[i]);
206 return (NULL);
207 }
208
209 void
exif_content_foreach_entry(ExifContent * content,ExifContentForeachEntryFunc func,void * data)210 exif_content_foreach_entry (ExifContent *content,
211 ExifContentForeachEntryFunc func, void *data)
212 {
213 unsigned int i;
214
215 if (!content || !func)
216 return;
217
218 for (i = 0; i < content->count; i++)
219 func (content->entries[i], data);
220 }
221
222 void
exif_content_log(ExifContent * content,ExifLog * log)223 exif_content_log (ExifContent *content, ExifLog *log)
224 {
225 if (!content || !content->priv || !log || content->priv->log == log)
226 return;
227
228 if (content->priv->log) exif_log_unref (content->priv->log);
229 content->priv->log = log;
230 exif_log_ref (log);
231 }
232
233 ExifIfd
exif_content_get_ifd(ExifContent * c)234 exif_content_get_ifd (ExifContent *c)
235 {
236 if (!c || !c->parent) return EXIF_IFD_COUNT;
237
238 return
239 ((c)->parent->ifd[EXIF_IFD_EXIF] == (c)) ? EXIF_IFD_EXIF :
240 ((c)->parent->ifd[EXIF_IFD_0] == (c)) ? EXIF_IFD_0 :
241 ((c)->parent->ifd[EXIF_IFD_1] == (c)) ? EXIF_IFD_1 :
242 ((c)->parent->ifd[EXIF_IFD_GPS] == (c)) ? EXIF_IFD_GPS :
243 ((c)->parent->ifd[EXIF_IFD_INTEROPERABILITY] == (c)) ? EXIF_IFD_INTEROPERABILITY :
244 EXIF_IFD_COUNT;
245 }
246
247 static void
fix_func(ExifEntry * e,void * UNUSED (data))248 fix_func (ExifEntry *e, void *UNUSED(data))
249 {
250 exif_entry_fix (e);
251 }
252
253 /*!
254 * Check if this entry is unknown and if so, delete it.
255 * \note Be careful calling this function in a loop. Deleting an entry from
256 * an ExifContent changes the index of subsequent entries, as well as the
257 * total size of the entries array.
258 */
259 static void
remove_not_recorded(ExifEntry * e,void * UNUSED (data))260 remove_not_recorded (ExifEntry *e, void *UNUSED(data))
261 {
262 ExifIfd ifd = exif_entry_get_ifd(e) ;
263 ExifContent *c = e->parent;
264 ExifDataType dt = exif_data_get_data_type (c->parent);
265 ExifTag t = e->tag;
266
267 if (exif_tag_get_support_level_in_ifd (t, ifd, dt) ==
268 EXIF_SUPPORT_LEVEL_NOT_RECORDED) {
269 exif_log (c->priv->log, EXIF_LOG_CODE_DEBUG, "exif-content",
270 "Tag 0x%04x is not recorded in IFD '%s' and has therefore been "
271 "removed.", t, exif_ifd_get_name (ifd));
272 exif_content_remove_entry (c, e);
273 }
274
275 }
276
277 void
exif_content_fix(ExifContent * c)278 exif_content_fix (ExifContent *c)
279 {
280 ExifIfd ifd = exif_content_get_ifd (c);
281 ExifDataType dt;
282 ExifEntry *e;
283 unsigned int i, num;
284
285 if (!c)
286 return;
287
288 dt = exif_data_get_data_type (c->parent);
289
290 /*
291 * First of all, fix all existing entries.
292 */
293 exif_content_foreach_entry (c, fix_func, NULL);
294
295 /*
296 * Go through each tag and if it's not recorded, remove it. If one
297 * is removed, exif_content_foreach_entry() will skip the next entry,
298 * so if this happens do the loop again from the beginning to ensure
299 * they're all checked. This could be avoided if we stop relying on
300 * exif_content_foreach_entry but loop intelligently here.
301 */
302 do {
303 num = c->count;
304 exif_content_foreach_entry (c, remove_not_recorded, NULL);
305 } while (num != c->count);
306
307 /*
308 * Then check for non-existing mandatory tags and create them if needed
309 */
310 num = exif_tag_table_count();
311 for (i = 0; i < num; ++i) {
312 const ExifTag t = exif_tag_table_get_tag (i);
313 if (exif_tag_get_support_level_in_ifd (t, ifd, dt) ==
314 EXIF_SUPPORT_LEVEL_MANDATORY) {
315 if (exif_content_get_entry (c, t))
316 /* This tag already exists */
317 continue;
318 exif_log (c->priv->log, EXIF_LOG_CODE_DEBUG, "exif-content",
319 "Tag '%s' is mandatory in IFD '%s' and has therefore been added.",
320 exif_tag_get_name_in_ifd (t, ifd), exif_ifd_get_name (ifd));
321 e = exif_entry_new ();
322 exif_content_add_entry (c, e);
323 exif_entry_initialize (e, t);
324 exif_entry_unref (e);
325 }
326 }
327 }
328