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
34struct _ExifContentPrivate
35{
36	unsigned int ref_count;
37
38	ExifMem *mem;
39	ExifLog *log;
40};
41
42ExifContent *
43exif_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
53ExifContent *
54exif_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
78void
79exif_content_ref (ExifContent *content)
80{
81	if (!content)
82		return;
83
84	content->priv->ref_count++;
85}
86
87void
88exif_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
98void
99exif_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
119void
120exif_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
138void
139exif_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) && entry->tag != EXIF_TAG_MAKER_NOTE) {
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
162void
163exif_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
201ExifEntry *
202exif_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
215ExifEntry *
216exif_content_get_huawei_makenote_entry (ExifContent *content)
217{
218	if (!content)
219		return (NULL);
220
221	ExifEntry *entry = NULL;
222	for (unsigned int i = 0; i < content->count; i++) {
223		entry = content->entries[i];
224		if (entry->tag == EXIF_TAG_MAKER_NOTE) {
225			if (entry->data && (entry->size >= 8) &&
226				(!memcmp(entry->data, "HUAWEI\0\0", 8))) {
227				return entry;
228			}
229		}
230	}
231
232	return (NULL);
233}
234
235void
236exif_content_foreach_entry (ExifContent *content,
237			    ExifContentForeachEntryFunc func, void *data)
238{
239	unsigned int i;
240
241	if (!content || !func)
242		return;
243
244	for (i = 0; i < content->count; i++)
245		func (content->entries[i], data);
246}
247
248void
249exif_content_log (ExifContent *content, ExifLog *log)
250{
251	if (!content || !content->priv || !log || content->priv->log == log)
252		return;
253
254	if (content->priv->log) exif_log_unref (content->priv->log);
255	content->priv->log = log;
256	exif_log_ref (log);
257}
258
259ExifIfd
260exif_content_get_ifd (ExifContent *c)
261{
262	if (!c || !c->parent) return EXIF_IFD_COUNT;
263
264	return
265		((c)->parent->ifd[EXIF_IFD_EXIF] == (c)) ? EXIF_IFD_EXIF :
266		((c)->parent->ifd[EXIF_IFD_0] == (c)) ? EXIF_IFD_0 :
267		((c)->parent->ifd[EXIF_IFD_1] == (c)) ? EXIF_IFD_1 :
268		((c)->parent->ifd[EXIF_IFD_GPS] == (c)) ? EXIF_IFD_GPS :
269		((c)->parent->ifd[EXIF_IFD_INTEROPERABILITY] == (c)) ? EXIF_IFD_INTEROPERABILITY :
270		EXIF_IFD_COUNT;
271}
272
273static void
274fix_func (ExifEntry *e, void *UNUSED(data))
275{
276	exif_entry_fix (e);
277}
278
279/*!
280 * Check if this entry is unknown and if so, delete it.
281 * \note Be careful calling this function in a loop. Deleting an entry from
282 * an ExifContent changes the index of subsequent entries, as well as the
283 * total size of the entries array.
284 */
285static void
286remove_not_recorded (ExifEntry *e, void *UNUSED(data))
287{
288	ExifIfd ifd = exif_entry_get_ifd(e) ;
289	ExifContent *c = e->parent;
290	ExifDataType dt = exif_data_get_data_type (c->parent);
291	ExifTag t = e->tag;
292
293	if (exif_tag_get_support_level_in_ifd (t, ifd, dt) ==
294			 EXIF_SUPPORT_LEVEL_NOT_RECORDED) {
295		exif_log (c->priv->log, EXIF_LOG_CODE_DEBUG, "exif-content",
296				"Tag 0x%04x is not recorded in IFD '%s' and has therefore been "
297				"removed.", t, exif_ifd_get_name (ifd));
298		exif_content_remove_entry (c, e);
299	}
300
301}
302
303void
304exif_content_fix (ExifContent *c)
305{
306	ExifIfd ifd = exif_content_get_ifd (c);
307	ExifDataType dt;
308	ExifEntry *e;
309	unsigned int i, num;
310
311	if (!c)
312		return;
313
314	dt = exif_data_get_data_type (c->parent);
315
316	/*
317	 * First of all, fix all existing entries.
318	 */
319	exif_content_foreach_entry (c, fix_func, NULL);
320
321	/*
322	 * Go through each tag and if it's not recorded, remove it. If one
323	 * is removed, exif_content_foreach_entry() will skip the next entry,
324	 * so if this happens do the loop again from the beginning to ensure
325	 * they're all checked. This could be avoided if we stop relying on
326	 * exif_content_foreach_entry but loop intelligently here.
327	 */
328	do {
329		num = c->count;
330		exif_content_foreach_entry (c, remove_not_recorded, NULL);
331	} while (num != c->count);
332
333	/*
334	 * Then check for non-existing mandatory tags and create them if needed
335	 */
336	num = exif_tag_table_count();
337	for (i = 0; i < num; ++i) {
338		const ExifTag t = exif_tag_table_get_tag (i);
339		if (exif_tag_get_support_level_in_ifd (t, ifd, dt) ==
340			EXIF_SUPPORT_LEVEL_MANDATORY) {
341			if (exif_content_get_entry (c, t))
342				/* This tag already exists */
343				continue;
344			exif_log (c->priv->log, EXIF_LOG_CODE_DEBUG, "exif-content",
345					"Tag '%s' is mandatory in IFD '%s' and has therefore been added.",
346					exif_tag_get_name_in_ifd (t, ifd), exif_ifd_get_name (ifd));
347			e = exif_entry_new ();
348			exif_content_add_entry (c, e);
349			exif_entry_initialize (e, t);
350			exif_entry_unref (e);
351		}
352	}
353}
354