libFLAC/cpu.c: Get rid of OS_IS_ANDROID function
[flac.git] / src / libFLAC / metadata_iterators.c
1 /* libFLAC - Free Lossless Audio Codec library
2  * Copyright (C) 2001-2009  Josh Coalson
3  * Copyright (C) 2011-2014  Xiph.Org Foundation
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * - Redistributions of source code must retain the above copyright
10  * notice, this list of conditions and the following disclaimer.
11  *
12  * - Redistributions in binary form must reproduce the above copyright
13  * notice, this list of conditions and the following disclaimer in the
14  * documentation and/or other materials provided with the distribution.
15  *
16  * - Neither the name of the Xiph.org Foundation nor the names of its
17  * contributors may be used to endorse or promote products derived from
18  * this software without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
24  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
26  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
27  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
28  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
29  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
30  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32
33 #ifdef HAVE_CONFIG_H
34 #  include <config.h>
35 #endif
36
37 #include <errno.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <stdarg.h>
42
43 #include <sys/stat.h> /* for stat(), maybe chmod() */
44
45 #include "private/metadata.h"
46
47 #include "FLAC/assert.h"
48 #include "FLAC/stream_decoder.h"
49 #include "share/alloc.h"
50 #include "share/compat.h"
51 #include "share/macros.h"
52 #include "share/safe_str.h"
53 #include "private/macros.h"
54 #include "private/memory.h"
55
56 /* Alias the first (in share/alloc.h) to the second (in src/libFLAC/memory.c). */
57 #define safe_malloc_mul_2op_ safe_malloc_mul_2op_p
58
59 /****************************************************************************
60  *
61  * Local function declarations
62  *
63  ***************************************************************************/
64
65 static void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes);
66 static void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes);
67 static void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes);
68 static FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes);
69 static FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes);
70 static FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes);
71
72 static FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator);
73 static FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block);
74 static FLAC__bool read_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__bool *is_last, FLAC__MetadataType *type, unsigned *length);
75 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata *block);
76 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_StreamInfo *block);
77 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata_Padding *block, unsigned block_length);
78 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Application *block, unsigned block_length);
79 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_SeekTable *block, unsigned block_length);
80 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_entry_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment_Entry *entry, unsigned max_length);
81 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata_VorbisComment *block, unsigned block_length);
82 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet_Track *track);
83 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet *block);
84 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Picture *block);
85 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Unknown *block, unsigned block_length);
86
87 static FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block);
88 static FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block);
89 static FLAC__bool write_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block);
90 static FLAC__bool write_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block);
91 static FLAC__bool write_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_StreamInfo *block);
92 static FLAC__bool write_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Padding *block, unsigned block_length);
93 static FLAC__bool write_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Application *block, unsigned block_length);
94 static FLAC__bool write_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_SeekTable *block);
95 static FLAC__bool write_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_VorbisComment *block);
96 static FLAC__bool write_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_CueSheet *block);
97 static FLAC__bool write_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Picture *block);
98 static FLAC__bool write_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Unknown *block, unsigned block_length);
99
100 static FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block);
101 static FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last);
102 static FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append);
103
104 static void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator);
105 static FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator);
106
107 static unsigned seek_to_first_metadata_block_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb);
108 static unsigned seek_to_first_metadata_block_(FILE *f);
109
110 static FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append);
111 static FLAC__bool simple_iterator_copy_file_postfix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, int fixup_is_last_code, FLAC__off_t fixup_is_last_flag_offset, FLAC__bool backup);
112
113 static FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status);
114 static FLAC__bool copy_n_bytes_from_file_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOHandle temp_handle, FLAC__IOCallback_Write temp_write_cb, FLAC__off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status);
115 static FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status);
116 static FLAC__bool copy_remaining_bytes_from_file_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Eof eof_cb, FLAC__IOHandle temp_handle, FLAC__IOCallback_Write temp_write_cb, FLAC__Metadata_SimpleIteratorStatus *status);
117
118 static FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status);
119 static FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status);
120 static void cleanup_tempfile_(FILE **tempfile, char **tempfilename);
121
122 static FLAC__bool get_file_stats_(const char *filename, struct flac_stat_s *stats);
123 static void set_file_stats_(const char *filename, struct flac_stat_s *stats);
124
125 static int fseek_wrapper_(FLAC__IOHandle handle, FLAC__int64 offset, int whence);
126 static FLAC__int64 ftell_wrapper_(FLAC__IOHandle handle);
127
128 static FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status);
129
130
131 #ifdef FLAC__VALGRIND_TESTING
132 static size_t local__fwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream)
133 {
134         size_t ret = fwrite(ptr, size, nmemb, stream);
135         if(!ferror(stream))
136                 fflush(stream);
137         return ret;
138 }
139 #else
140 #define local__fwrite fwrite
141 #endif
142
143 /****************************************************************************
144  *
145  * Level 0 implementation
146  *
147  ***************************************************************************/
148
149 static FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data);
150 static void metadata_callback_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data);
151 static void error_callback_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data);
152
153 typedef struct {
154         FLAC__bool got_error;
155         FLAC__StreamMetadata *object;
156 } level0_client_data;
157
158 static FLAC__StreamMetadata *get_one_metadata_block_(const char *filename, FLAC__MetadataType type)
159 {
160         level0_client_data cd;
161         FLAC__StreamDecoder *decoder;
162
163         FLAC__ASSERT(0 != filename);
164
165         cd.got_error = false;
166         cd.object = 0;
167
168         decoder = FLAC__stream_decoder_new();
169
170         if(0 == decoder)
171                 return 0;
172
173         FLAC__stream_decoder_set_md5_checking(decoder, false);
174         FLAC__stream_decoder_set_metadata_ignore_all(decoder);
175         FLAC__stream_decoder_set_metadata_respond(decoder, type);
176
177         if(FLAC__stream_decoder_init_file(decoder, filename, write_callback_, metadata_callback_, error_callback_, &cd) != FLAC__STREAM_DECODER_INIT_STATUS_OK || cd.got_error) {
178                 (void)FLAC__stream_decoder_finish(decoder);
179                 FLAC__stream_decoder_delete(decoder);
180                 return 0;
181         }
182
183         if(!FLAC__stream_decoder_process_until_end_of_metadata(decoder) || cd.got_error) {
184                 (void)FLAC__stream_decoder_finish(decoder);
185                 FLAC__stream_decoder_delete(decoder);
186                 if(0 != cd.object)
187                         FLAC__metadata_object_delete(cd.object);
188                 return 0;
189         }
190
191         (void)FLAC__stream_decoder_finish(decoder);
192         FLAC__stream_decoder_delete(decoder);
193
194         return cd.object;
195 }
196
197 FLAC_API FLAC__bool FLAC__metadata_get_streaminfo(const char *filename, FLAC__StreamMetadata *streaminfo)
198 {
199         FLAC__StreamMetadata *object;
200
201         FLAC__ASSERT(0 != filename);
202         FLAC__ASSERT(0 != streaminfo);
203
204         object = get_one_metadata_block_(filename, FLAC__METADATA_TYPE_STREAMINFO);
205
206         if (object) {
207                 /* can just copy the contents since STREAMINFO has no internal structure */
208                 *streaminfo = *object;
209                 FLAC__metadata_object_delete(object);
210                 return true;
211         }
212         else {
213                 return false;
214         }
215 }
216
217 FLAC_API FLAC__bool FLAC__metadata_get_tags(const char *filename, FLAC__StreamMetadata **tags)
218 {
219         FLAC__ASSERT(0 != filename);
220         FLAC__ASSERT(0 != tags);
221
222         *tags = get_one_metadata_block_(filename, FLAC__METADATA_TYPE_VORBIS_COMMENT);
223
224         return 0 != *tags;
225 }
226
227 FLAC_API FLAC__bool FLAC__metadata_get_cuesheet(const char *filename, FLAC__StreamMetadata **cuesheet)
228 {
229         FLAC__ASSERT(0 != filename);
230         FLAC__ASSERT(0 != cuesheet);
231
232         *cuesheet = get_one_metadata_block_(filename, FLAC__METADATA_TYPE_CUESHEET);
233
234         return 0 != *cuesheet;
235 }
236
237 FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
238 {
239         (void)decoder, (void)frame, (void)buffer, (void)client_data;
240
241         return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;
242 }
243
244 void metadata_callback_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
245 {
246         level0_client_data *cd = (level0_client_data *)client_data;
247         (void)decoder;
248
249         /*
250          * we assume we only get here when the one metadata block we were
251          * looking for was passed to us
252          */
253         if(!cd->got_error && 0 == cd->object) {
254                 if(0 == (cd->object = FLAC__metadata_object_clone(metadata)))
255                         cd->got_error = true;
256         }
257 }
258
259 void error_callback_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
260 {
261         level0_client_data *cd = (level0_client_data *)client_data;
262         (void)decoder;
263
264         if(status != FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC)
265                 cd->got_error = true;
266 }
267
268 FLAC_API FLAC__bool FLAC__metadata_get_picture(const char *filename, FLAC__StreamMetadata **picture, FLAC__StreamMetadata_Picture_Type type, const char *mime_type, const FLAC__byte *description, unsigned max_width, unsigned max_height, unsigned max_depth, unsigned max_colors)
269 {
270         FLAC__Metadata_SimpleIterator *it;
271         FLAC__uint64 max_area_seen = 0;
272         FLAC__uint64 max_depth_seen = 0;
273
274         FLAC__ASSERT(0 != filename);
275         FLAC__ASSERT(0 != picture);
276
277         *picture = 0;
278
279         it = FLAC__metadata_simple_iterator_new();
280         if(0 == it)
281                 return false;
282         if(!FLAC__metadata_simple_iterator_init(it, filename, /*read_only=*/true, /*preserve_file_stats=*/true)) {
283                 FLAC__metadata_simple_iterator_delete(it);
284                 return false;
285         }
286         do {
287                 if(FLAC__metadata_simple_iterator_get_block_type(it) == FLAC__METADATA_TYPE_PICTURE) {
288                         FLAC__StreamMetadata *obj = FLAC__metadata_simple_iterator_get_block(it);
289                         FLAC__uint64 area = (FLAC__uint64)obj->data.picture.width * (FLAC__uint64)obj->data.picture.height;
290                         /* check constraints */
291                         if(
292                                 (type == (FLAC__StreamMetadata_Picture_Type)(-1) || type == obj->data.picture.type) &&
293                                 (mime_type == 0 || !strcmp(mime_type, obj->data.picture.mime_type)) &&
294                                 (description == 0 || !strcmp((const char *)description, (const char *)obj->data.picture.description)) &&
295                                 obj->data.picture.width <= max_width &&
296                                 obj->data.picture.height <= max_height &&
297                                 obj->data.picture.depth <= max_depth &&
298                                 obj->data.picture.colors <= max_colors &&
299                                 (area > max_area_seen || (area == max_area_seen && obj->data.picture.depth > max_depth_seen))
300                         ) {
301                                 if(*picture)
302                                         FLAC__metadata_object_delete(*picture);
303                                 *picture = obj;
304                                 max_area_seen = area;
305                                 max_depth_seen = obj->data.picture.depth;
306                         }
307                         else {
308                                 FLAC__metadata_object_delete(obj);
309                         }
310                 }
311         } while(FLAC__metadata_simple_iterator_next(it));
312
313         FLAC__metadata_simple_iterator_delete(it);
314
315         return (0 != *picture);
316 }
317
318
319 /****************************************************************************
320  *
321  * Level 1 implementation
322  *
323  ***************************************************************************/
324
325 #define SIMPLE_ITERATOR_MAX_PUSH_DEPTH (1+4)
326 /* 1 for initial offset, +4 for our own personal use */
327
328 struct FLAC__Metadata_SimpleIterator {
329         FILE *file;
330         char *filename, *tempfile_path_prefix;
331         struct flac_stat_s stats;
332         FLAC__bool has_stats;
333         FLAC__bool is_writable;
334         FLAC__Metadata_SimpleIteratorStatus status;
335         FLAC__off_t offset[SIMPLE_ITERATOR_MAX_PUSH_DEPTH];
336         FLAC__off_t first_offset; /* this is the offset to the STREAMINFO block */
337         unsigned depth;
338         /* this is the metadata block header of the current block we are pointing to: */
339         FLAC__bool is_last;
340         FLAC__MetadataType type;
341         unsigned length;
342 };
343
344 FLAC_API const char * const FLAC__Metadata_SimpleIteratorStatusString[] = {
345         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK",
346         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT",
347         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE",
348         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE",
349         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE",
350         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA",
351         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR",
352         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR",
353         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR",
354         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR",
355         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR",
356         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR",
357         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR"
358 };
359
360
361 FLAC_API FLAC__Metadata_SimpleIterator *FLAC__metadata_simple_iterator_new(void)
362 {
363         FLAC__Metadata_SimpleIterator *iterator = calloc(1, sizeof(FLAC__Metadata_SimpleIterator));
364
365         if(0 != iterator) {
366                 iterator->file = 0;
367                 iterator->filename = 0;
368                 iterator->tempfile_path_prefix = 0;
369                 iterator->has_stats = false;
370                 iterator->is_writable = false;
371                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
372                 iterator->first_offset = iterator->offset[0] = -1;
373                 iterator->depth = 0;
374         }
375
376         return iterator;
377 }
378
379 static void simple_iterator_free_guts_(FLAC__Metadata_SimpleIterator *iterator)
380 {
381         FLAC__ASSERT(0 != iterator);
382
383         if(0 != iterator->file) {
384                 fclose(iterator->file);
385                 iterator->file = 0;
386                 if(iterator->has_stats)
387                         set_file_stats_(iterator->filename, &iterator->stats);
388         }
389         if(0 != iterator->filename) {
390                 free(iterator->filename);
391                 iterator->filename = 0;
392         }
393         if(0 != iterator->tempfile_path_prefix) {
394                 free(iterator->tempfile_path_prefix);
395                 iterator->tempfile_path_prefix = 0;
396         }
397 }
398
399 FLAC_API void FLAC__metadata_simple_iterator_delete(FLAC__Metadata_SimpleIterator *iterator)
400 {
401         FLAC__ASSERT(0 != iterator);
402
403         simple_iterator_free_guts_(iterator);
404         free(iterator);
405 }
406
407 FLAC_API FLAC__Metadata_SimpleIteratorStatus FLAC__metadata_simple_iterator_status(FLAC__Metadata_SimpleIterator *iterator)
408 {
409         FLAC__Metadata_SimpleIteratorStatus status;
410
411         FLAC__ASSERT(0 != iterator);
412
413         status = iterator->status;
414         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
415         return status;
416 }
417
418 static FLAC__bool simple_iterator_prime_input_(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool read_only)
419 {
420         unsigned ret;
421
422         FLAC__ASSERT(0 != iterator);
423
424         if(read_only || 0 == (iterator->file = flac_fopen(iterator->filename, "r+b"))) {
425                 iterator->is_writable = false;
426                 if(read_only || errno == EACCES) {
427                         if(0 == (iterator->file = flac_fopen(iterator->filename, "rb"))) {
428                                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
429                                 return false;
430                         }
431                 }
432                 else {
433                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
434                         return false;
435                 }
436         }
437         else {
438                 iterator->is_writable = true;
439         }
440
441         ret = seek_to_first_metadata_block_(iterator->file);
442         switch(ret) {
443                 case 0:
444                         iterator->depth = 0;
445                         iterator->first_offset = iterator->offset[iterator->depth] = ftello(iterator->file);
446                         return read_metadata_block_header_(iterator);
447                 case 1:
448                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
449                         return false;
450                 case 2:
451                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
452                         return false;
453                 case 3:
454                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE;
455                         return false;
456                 default:
457                         FLAC__ASSERT(0);
458                         return false;
459         }
460 }
461
462 #if 0
463 @@@ If we decide to finish implementing this, put this comment back in metadata.h
464 /*
465  * The 'tempfile_path_prefix' allows you to specify a directory where
466  * tempfiles should go.  Remember that if your metadata edits cause the
467  * FLAC file to grow, the entire file will have to be rewritten.  If
468  * 'tempfile_path_prefix' is NULL, the temp file will be written in the
469  * same directory as the original FLAC file.  This makes replacing the
470  * original with the tempfile fast but requires extra space in the same
471  * partition for the tempfile.  If space is a problem, you can pass a
472  * directory name belonging to a different partition in
473  * 'tempfile_path_prefix'.  Note that you should use the forward slash
474  * '/' as the directory separator.  A trailing slash is not needed; it
475  * will be added automatically.
476  */
477 FLAC__bool FLAC__metadata_simple_iterator_init(FLAC__Metadata_SimpleIterator *iterator, const char *filename, FLAC__bool preserve_file_stats, const char *tempfile_path_prefix);
478 #endif
479
480 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_init(FLAC__Metadata_SimpleIterator *iterator, const char *filename, FLAC__bool read_only, FLAC__bool preserve_file_stats)
481 {
482         const char *tempfile_path_prefix = 0; /*@@@ search for comments near 'flac_rename(...)' for what it will take to finish implementing this */
483
484         FLAC__ASSERT(0 != iterator);
485         FLAC__ASSERT(0 != filename);
486
487         simple_iterator_free_guts_(iterator);
488
489         if(!read_only && preserve_file_stats)
490                 iterator->has_stats = get_file_stats_(filename, &iterator->stats);
491
492         if(0 == (iterator->filename = strdup(filename))) {
493                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
494                 return false;
495         }
496         if(0 != tempfile_path_prefix && 0 == (iterator->tempfile_path_prefix = strdup(tempfile_path_prefix))) {
497                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
498                 return false;
499         }
500
501         return simple_iterator_prime_input_(iterator, read_only);
502 }
503
504 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_is_writable(const FLAC__Metadata_SimpleIterator *iterator)
505 {
506         FLAC__ASSERT(0 != iterator);
507         FLAC__ASSERT(0 != iterator->file);
508
509         return iterator->is_writable;
510 }
511
512 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_next(FLAC__Metadata_SimpleIterator *iterator)
513 {
514         FLAC__ASSERT(0 != iterator);
515         FLAC__ASSERT(0 != iterator->file);
516
517         if(iterator->is_last)
518                 return false;
519
520         if(0 != fseeko(iterator->file, iterator->length, SEEK_CUR)) {
521                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
522                 return false;
523         }
524
525         iterator->offset[iterator->depth] = ftello(iterator->file);
526
527         return read_metadata_block_header_(iterator);
528 }
529
530 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_prev(FLAC__Metadata_SimpleIterator *iterator)
531 {
532         FLAC__off_t this_offset;
533
534         FLAC__ASSERT(0 != iterator);
535         FLAC__ASSERT(0 != iterator->file);
536
537         if(iterator->offset[iterator->depth] == iterator->first_offset)
538                 return false;
539
540         if(0 != fseeko(iterator->file, iterator->first_offset, SEEK_SET)) {
541                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
542                 return false;
543         }
544         this_offset = iterator->first_offset;
545         if(!read_metadata_block_header_(iterator))
546                 return false;
547
548         /* we ignore any error from ftello() and catch it in fseeko() */
549         while(ftello(iterator->file) + (FLAC__off_t)iterator->length < iterator->offset[iterator->depth]) {
550                 if(0 != fseeko(iterator->file, iterator->length, SEEK_CUR)) {
551                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
552                         return false;
553                 }
554                 this_offset = ftello(iterator->file);
555                 if(!read_metadata_block_header_(iterator))
556                         return false;
557         }
558
559         iterator->offset[iterator->depth] = this_offset;
560
561         return true;
562 }
563
564 /*@@@@add to tests*/
565 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_is_last(const FLAC__Metadata_SimpleIterator *iterator)
566 {
567         FLAC__ASSERT(0 != iterator);
568         FLAC__ASSERT(0 != iterator->file);
569
570         return iterator->is_last;
571 }
572
573 /*@@@@add to tests*/
574 FLAC_API off_t FLAC__metadata_simple_iterator_get_block_offset(const FLAC__Metadata_SimpleIterator *iterator)
575 {
576         FLAC__ASSERT(0 != iterator);
577         FLAC__ASSERT(0 != iterator->file);
578
579         return iterator->offset[iterator->depth];
580 }
581
582 FLAC_API FLAC__MetadataType FLAC__metadata_simple_iterator_get_block_type(const FLAC__Metadata_SimpleIterator *iterator)
583 {
584         FLAC__ASSERT(0 != iterator);
585         FLAC__ASSERT(0 != iterator->file);
586
587         return iterator->type;
588 }
589
590 /*@@@@add to tests*/
591 FLAC_API unsigned FLAC__metadata_simple_iterator_get_block_length(const FLAC__Metadata_SimpleIterator *iterator)
592 {
593         FLAC__ASSERT(0 != iterator);
594         FLAC__ASSERT(0 != iterator->file);
595
596         return iterator->length;
597 }
598
599 /*@@@@add to tests*/
600 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_get_application_id(FLAC__Metadata_SimpleIterator *iterator, FLAC__byte *id)
601 {
602         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
603
604         FLAC__ASSERT(0 != iterator);
605         FLAC__ASSERT(0 != iterator->file);
606         FLAC__ASSERT(0 != id);
607
608         if(iterator->type != FLAC__METADATA_TYPE_APPLICATION) {
609                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
610                 return false;
611         }
612
613         if(fread(id, 1, id_bytes, iterator->file) != id_bytes) {
614                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
615                 return false;
616         }
617
618         /* back up */
619         if(0 != fseeko(iterator->file, -((int)id_bytes), SEEK_CUR)) {
620                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
621                 return false;
622         }
623
624         return true;
625 }
626
627 FLAC_API FLAC__StreamMetadata *FLAC__metadata_simple_iterator_get_block(FLAC__Metadata_SimpleIterator *iterator)
628 {
629         FLAC__StreamMetadata *block = FLAC__metadata_object_new(iterator->type);
630
631         FLAC__ASSERT(0 != iterator);
632         FLAC__ASSERT(0 != iterator->file);
633
634         if(0 != block) {
635                 block->is_last = iterator->is_last;
636                 block->length = iterator->length;
637
638                 if(!read_metadata_block_data_(iterator, block)) {
639                         FLAC__metadata_object_delete(block);
640                         return 0;
641                 }
642
643                 /* back up to the beginning of the block data to stay consistent */
644                 if(0 != fseeko(iterator->file, iterator->offset[iterator->depth] + FLAC__STREAM_METADATA_HEADER_LENGTH, SEEK_SET)) {
645                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
646                         FLAC__metadata_object_delete(block);
647                         return 0;
648                 }
649         }
650         else
651                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
652
653         return block;
654 }
655
656 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_set_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding)
657 {
658         FLAC__ASSERT_DECLARATION(FLAC__off_t debug_target_offset = iterator->offset[iterator->depth];)
659         FLAC__bool ret;
660
661         FLAC__ASSERT(0 != iterator);
662         FLAC__ASSERT(0 != iterator->file);
663         FLAC__ASSERT(0 != block);
664
665         if(!iterator->is_writable) {
666                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE;
667                 return false;
668         }
669
670         if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO || block->type == FLAC__METADATA_TYPE_STREAMINFO) {
671                 if(iterator->type != block->type) {
672                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
673                         return false;
674                 }
675         }
676
677         block->is_last = iterator->is_last;
678
679         if(iterator->length == block->length)
680                 return write_metadata_block_stationary_(iterator, block);
681         else if(iterator->length > block->length) {
682                 if(use_padding && iterator->length >= FLAC__STREAM_METADATA_HEADER_LENGTH + block->length) {
683                         ret = write_metadata_block_stationary_with_padding_(iterator, block, iterator->length - FLAC__STREAM_METADATA_HEADER_LENGTH - block->length, block->is_last);
684                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
685                         FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
686                         return ret;
687                 }
688                 else {
689                         ret = rewrite_whole_file_(iterator, block, /*append=*/false);
690                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
691                         FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
692                         return ret;
693                 }
694         }
695         else /* iterator->length < block->length */ {
696                 unsigned padding_leftover = 0;
697                 FLAC__bool padding_is_last = false;
698                 if(use_padding) {
699                         /* first see if we can even use padding */
700                         if(iterator->is_last) {
701                                 use_padding = false;
702                         }
703                         else {
704                                 const unsigned extra_padding_bytes_required = block->length - iterator->length;
705                                 simple_iterator_push_(iterator);
706                                 if(!FLAC__metadata_simple_iterator_next(iterator)) {
707                                         (void)simple_iterator_pop_(iterator);
708                                         return false;
709                                 }
710                                 if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
711                                         use_padding = false;
712                                 }
713                                 else {
714                                         if(FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length == extra_padding_bytes_required) {
715                                                 padding_leftover = 0;
716                                                 block->is_last = iterator->is_last;
717                                         }
718                                         else if(iterator->length < extra_padding_bytes_required)
719                                                 use_padding = false;
720                                         else {
721                                                 padding_leftover = FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length - extra_padding_bytes_required;
722                                                 padding_is_last = iterator->is_last;
723                                                 block->is_last = false;
724                                         }
725                                 }
726                                 if(!simple_iterator_pop_(iterator))
727                                         return false;
728                         }
729                 }
730                 if(use_padding) {
731                         if(padding_leftover == 0) {
732                                 ret = write_metadata_block_stationary_(iterator, block);
733                                 FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
734                                 FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
735                                 return ret;
736                         }
737                         else {
738                                 FLAC__ASSERT(padding_leftover >= FLAC__STREAM_METADATA_HEADER_LENGTH);
739                                 ret = write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover - FLAC__STREAM_METADATA_HEADER_LENGTH, padding_is_last);
740                                 FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
741                                 FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
742                                 return ret;
743                         }
744                 }
745                 else {
746                         ret = rewrite_whole_file_(iterator, block, /*append=*/false);
747                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
748                         FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
749                         return ret;
750                 }
751         }
752 }
753
754 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_insert_block_after(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding)
755 {
756         unsigned padding_leftover = 0;
757         FLAC__bool padding_is_last = false;
758
759         FLAC__ASSERT_DECLARATION(FLAC__off_t debug_target_offset = iterator->offset[iterator->depth] + FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length;)
760         FLAC__bool ret;
761
762         FLAC__ASSERT(0 != iterator);
763         FLAC__ASSERT(0 != iterator->file);
764         FLAC__ASSERT(0 != block);
765
766         if(!iterator->is_writable) {
767                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE;
768                 return false;
769         }
770
771         if(block->type == FLAC__METADATA_TYPE_STREAMINFO) {
772                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
773                 return false;
774         }
775
776         block->is_last = iterator->is_last;
777
778         if(use_padding) {
779                 /* first see if we can even use padding */
780                 if(iterator->is_last) {
781                         use_padding = false;
782                 }
783                 else {
784                         simple_iterator_push_(iterator);
785                         if(!FLAC__metadata_simple_iterator_next(iterator)) {
786                                 (void)simple_iterator_pop_(iterator);
787                                 return false;
788                         }
789                         if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
790                                 use_padding = false;
791                         }
792                         else {
793                                 if(iterator->length == block->length) {
794                                         padding_leftover = 0;
795                                         block->is_last = iterator->is_last;
796                                 }
797                                 else if(iterator->length < FLAC__STREAM_METADATA_HEADER_LENGTH + block->length)
798                                         use_padding = false;
799                                 else {
800                                         padding_leftover = iterator->length - block->length;
801                                         padding_is_last = iterator->is_last;
802                                         block->is_last = false;
803                                 }
804                         }
805                         if(!simple_iterator_pop_(iterator))
806                                 return false;
807                 }
808         }
809         if(use_padding) {
810                 /* move to the next block, which is suitable padding */
811                 if(!FLAC__metadata_simple_iterator_next(iterator))
812                         return false;
813                 if(padding_leftover == 0) {
814                         ret = write_metadata_block_stationary_(iterator, block);
815                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
816                         FLAC__ASSERT(ftello(iterator->file) == debug_target_offset + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
817                         return ret;
818                 }
819                 else {
820                         FLAC__ASSERT(padding_leftover >= FLAC__STREAM_METADATA_HEADER_LENGTH);
821                         ret = write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover - FLAC__STREAM_METADATA_HEADER_LENGTH, padding_is_last);
822                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
823                         FLAC__ASSERT(ftello(iterator->file) == debug_target_offset + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
824                         return ret;
825                 }
826         }
827         else {
828                 ret = rewrite_whole_file_(iterator, block, /*append=*/true);
829                 FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
830                 FLAC__ASSERT(ftello(iterator->file) == debug_target_offset + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
831                 return ret;
832         }
833 }
834
835 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_delete_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool use_padding)
836 {
837         FLAC__ASSERT_DECLARATION(FLAC__off_t debug_target_offset = iterator->offset[iterator->depth];)
838         FLAC__bool ret;
839
840         if(!iterator->is_writable) {
841                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE;
842                 return false;
843         }
844
845         if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO) {
846                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
847                 return false;
848         }
849
850         if(use_padding) {
851                 FLAC__StreamMetadata *padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING);
852                 if(0 == padding) {
853                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
854                         return false;
855                 }
856                 padding->length = iterator->length;
857                 if(!FLAC__metadata_simple_iterator_set_block(iterator, padding, false)) {
858                         FLAC__metadata_object_delete(padding);
859                         return false;
860                 }
861                 FLAC__metadata_object_delete(padding);
862                 if(!FLAC__metadata_simple_iterator_prev(iterator))
863                         return false;
864                 FLAC__ASSERT(iterator->offset[iterator->depth] + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (FLAC__off_t)iterator->length == debug_target_offset);
865                 FLAC__ASSERT(ftello(iterator->file) + (FLAC__off_t)iterator->length == debug_target_offset);
866                 return true;
867         }
868         else {
869                 ret = rewrite_whole_file_(iterator, 0, /*append=*/false);
870                 FLAC__ASSERT(iterator->offset[iterator->depth] + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (FLAC__off_t)iterator->length == debug_target_offset);
871                 FLAC__ASSERT(ftello(iterator->file) + (FLAC__off_t)iterator->length == debug_target_offset);
872                 return ret;
873         }
874 }
875
876
877
878 /****************************************************************************
879  *
880  * Level 2 implementation
881  *
882  ***************************************************************************/
883
884
885 typedef struct FLAC__Metadata_Node {
886         FLAC__StreamMetadata *data;
887         struct FLAC__Metadata_Node *prev, *next;
888 } FLAC__Metadata_Node;
889
890 struct FLAC__Metadata_Chain {
891         char *filename; /* will be NULL if using callbacks */
892         FLAC__bool is_ogg;
893         FLAC__Metadata_Node *head;
894         FLAC__Metadata_Node *tail;
895         unsigned nodes;
896         FLAC__Metadata_ChainStatus status;
897         FLAC__off_t first_offset, last_offset;
898         /*
899          * This is the length of the chain initially read from the FLAC file.
900          * it is used to compare against the current length to decide whether
901          * or not the whole file has to be rewritten.
902          */
903         FLAC__off_t initial_length;
904         /* @@@ hacky, these are currently only needed by ogg reader */
905         FLAC__IOHandle handle;
906         FLAC__IOCallback_Read read_cb;
907 };
908
909 struct FLAC__Metadata_Iterator {
910         FLAC__Metadata_Chain *chain;
911         FLAC__Metadata_Node *current;
912 };
913
914 FLAC_API const char * const FLAC__Metadata_ChainStatusString[] = {
915         "FLAC__METADATA_CHAIN_STATUS_OK",
916         "FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT",
917         "FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE",
918         "FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE",
919         "FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE",
920         "FLAC__METADATA_CHAIN_STATUS_BAD_METADATA",
921         "FLAC__METADATA_CHAIN_STATUS_READ_ERROR",
922         "FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR",
923         "FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR",
924         "FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR",
925         "FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR",
926         "FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR",
927         "FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR",
928         "FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS",
929         "FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH",
930         "FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL"
931 };
932
933
934 static FLAC__Metadata_Node *node_new_(void)
935 {
936         return calloc(1, sizeof(FLAC__Metadata_Node));
937 }
938
939 static void node_delete_(FLAC__Metadata_Node *node)
940 {
941         FLAC__ASSERT(0 != node);
942         if(0 != node->data)
943                 FLAC__metadata_object_delete(node->data);
944         free(node);
945 }
946
947 static void chain_init_(FLAC__Metadata_Chain *chain)
948 {
949         FLAC__ASSERT(0 != chain);
950
951         chain->filename = 0;
952         chain->is_ogg = false;
953         chain->head = chain->tail = 0;
954         chain->nodes = 0;
955         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
956         chain->initial_length = 0;
957         chain->read_cb = 0;
958 }
959
960 static void chain_clear_(FLAC__Metadata_Chain *chain)
961 {
962         FLAC__Metadata_Node *node, *next;
963
964         FLAC__ASSERT(0 != chain);
965
966         for(node = chain->head; node; ) {
967                 next = node->next;
968                 node_delete_(node);
969                 node = next;
970         }
971
972         if(0 != chain->filename)
973                 free(chain->filename);
974
975         chain_init_(chain);
976 }
977
978 static void chain_append_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
979 {
980         FLAC__ASSERT(0 != chain);
981         FLAC__ASSERT(0 != node);
982         FLAC__ASSERT(0 != node->data);
983
984         node->next = node->prev = 0;
985         node->data->is_last = true;
986         if(0 != chain->tail)
987                 chain->tail->data->is_last = false;
988
989         if(0 == chain->head)
990                 chain->head = node;
991         else {
992                 FLAC__ASSERT(0 != chain->tail);
993                 chain->tail->next = node;
994                 node->prev = chain->tail;
995         }
996         chain->tail = node;
997         chain->nodes++;
998 }
999
1000 static void chain_remove_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
1001 {
1002         FLAC__ASSERT(0 != chain);
1003         FLAC__ASSERT(0 != node);
1004
1005         if(node == chain->head)
1006                 chain->head = node->next;
1007         else
1008                 node->prev->next = node->next;
1009
1010         if(node == chain->tail)
1011                 chain->tail = node->prev;
1012         else
1013                 node->next->prev = node->prev;
1014
1015         if(0 != chain->tail)
1016                 chain->tail->data->is_last = true;
1017
1018         chain->nodes--;
1019 }
1020
1021 static void chain_delete_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
1022 {
1023         chain_remove_node_(chain, node);
1024         node_delete_(node);
1025 }
1026
1027 static FLAC__off_t chain_calculate_length_(FLAC__Metadata_Chain *chain)
1028 {
1029         const FLAC__Metadata_Node *node;
1030         FLAC__off_t length = 0;
1031         for(node = chain->head; node; node = node->next)
1032                 length += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1033         return length;
1034 }
1035
1036 static void iterator_insert_node_(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Node *node)
1037 {
1038         FLAC__ASSERT(0 != node);
1039         FLAC__ASSERT(0 != node->data);
1040         FLAC__ASSERT(0 != iterator);
1041         FLAC__ASSERT(0 != iterator->current);
1042         FLAC__ASSERT(0 != iterator->chain);
1043         FLAC__ASSERT(0 != iterator->chain->head);
1044         FLAC__ASSERT(0 != iterator->chain->tail);
1045
1046         node->data->is_last = false;
1047
1048         node->prev = iterator->current->prev;
1049         node->next = iterator->current;
1050
1051         if(0 == node->prev)
1052                 iterator->chain->head = node;
1053         else
1054                 node->prev->next = node;
1055
1056         iterator->current->prev = node;
1057
1058         iterator->chain->nodes++;
1059 }
1060
1061 static void iterator_insert_node_after_(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Node *node)
1062 {
1063         FLAC__ASSERT(0 != node);
1064         FLAC__ASSERT(0 != node->data);
1065         FLAC__ASSERT(0 != iterator);
1066         FLAC__ASSERT(0 != iterator->current);
1067         FLAC__ASSERT(0 != iterator->chain);
1068         FLAC__ASSERT(0 != iterator->chain->head);
1069         FLAC__ASSERT(0 != iterator->chain->tail);
1070
1071         iterator->current->data->is_last = false;
1072
1073         node->prev = iterator->current;
1074         node->next = iterator->current->next;
1075
1076         if(0 == node->next)
1077                 iterator->chain->tail = node;
1078         else
1079                 node->next->prev = node;
1080
1081         node->prev->next = node;
1082
1083         iterator->chain->tail->data->is_last = true;
1084
1085         iterator->chain->nodes++;
1086 }
1087
1088 /* return true iff node and node->next are both padding */
1089 static FLAC__bool chain_merge_adjacent_padding_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
1090 {
1091         if(node->data->type == FLAC__METADATA_TYPE_PADDING && 0 != node->next && node->next->data->type == FLAC__METADATA_TYPE_PADDING) {
1092                 const unsigned growth = FLAC__STREAM_METADATA_HEADER_LENGTH + node->next->data->length;
1093                 node->data->length += growth; /* new block size can be greater than max metadata block size, but it'll be fixed later in chain_prepare_for_write_() */
1094
1095                 chain_delete_node_(chain, node->next);
1096                 return true;
1097         }
1098         else
1099                 return false;
1100 }
1101
1102 /* Returns the new length of the chain, or 0 if there was an error. */
1103 /* WATCHOUT: This can get called multiple times before a write, so
1104  * it should still work when this happens.
1105  */
1106 /* WATCHOUT: Make sure to also update the logic in
1107  * FLAC__metadata_chain_check_if_tempfile_needed() if the logic here changes.
1108  */
1109 static FLAC__off_t chain_prepare_for_write_(FLAC__Metadata_Chain *chain, FLAC__bool use_padding)
1110 {
1111         FLAC__off_t current_length = chain_calculate_length_(chain);
1112
1113         if(use_padding) {
1114                 /* if the metadata shrank and the last block is padding, we just extend the last padding block */
1115                 if(current_length < chain->initial_length && chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1116                         const FLAC__off_t delta = chain->initial_length - current_length;
1117                         chain->tail->data->length += delta;
1118                         current_length += delta;
1119                         FLAC__ASSERT(current_length == chain->initial_length);
1120                 }
1121                 /* if the metadata shrank more than 4 bytes then there's room to add another padding block */
1122                 else if(current_length + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH <= chain->initial_length) {
1123                         FLAC__StreamMetadata *padding;
1124                         FLAC__Metadata_Node *node;
1125                         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING))) {
1126                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1127                                 return 0;
1128                         }
1129                         padding->length = chain->initial_length - (FLAC__STREAM_METADATA_HEADER_LENGTH + current_length);
1130                         if(0 == (node = node_new_())) {
1131                                 FLAC__metadata_object_delete(padding);
1132                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1133                                 return 0;
1134                         }
1135                         node->data = padding;
1136                         chain_append_node_(chain, node);
1137                         current_length = chain_calculate_length_(chain);
1138                         FLAC__ASSERT(current_length == chain->initial_length);
1139                 }
1140                 /* if the metadata grew but the last block is padding, try cutting the padding to restore the original length so we don't have to rewrite the whole file */
1141                 else if(current_length > chain->initial_length) {
1142                         const FLAC__off_t delta = current_length - chain->initial_length;
1143                         if(chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1144                                 /* if the delta is exactly the size of the last padding block, remove the padding block */
1145                                 if((FLAC__off_t)chain->tail->data->length + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH == delta) {
1146                                         chain_delete_node_(chain, chain->tail);
1147                                         current_length = chain_calculate_length_(chain);
1148                                         FLAC__ASSERT(current_length == chain->initial_length);
1149                                 }
1150                                 /* if there is at least 'delta' bytes of padding, trim the padding down */
1151                                 else if((FLAC__off_t)chain->tail->data->length >= delta) {
1152                                         chain->tail->data->length -= delta;
1153                                         current_length -= delta;
1154                                         FLAC__ASSERT(current_length == chain->initial_length);
1155                                 }
1156                         }
1157                 }
1158         }
1159
1160         /* check sizes of all metadata blocks; reduce padding size if necessary */
1161         {
1162                 FLAC__Metadata_Node *node;
1163                 for (node = chain->head; node; node = node->next) {
1164                         if(node->data->length >= (1u << FLAC__STREAM_METADATA_LENGTH_LEN)) {
1165                                 if(node->data->type == FLAC__METADATA_TYPE_PADDING) {
1166                                         node->data->length = (1u << FLAC__STREAM_METADATA_LENGTH_LEN) - 1;
1167                                         current_length = chain_calculate_length_(chain);
1168                                 } else {
1169                                         chain->status = FLAC__METADATA_CHAIN_STATUS_BAD_METADATA;
1170                                         return 0;
1171                                 }
1172                         }
1173                 }
1174         }
1175
1176         return current_length;
1177 }
1178
1179 static FLAC__bool chain_read_cb_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb, FLAC__IOCallback_Tell tell_cb)
1180 {
1181         FLAC__Metadata_Node *node;
1182
1183         FLAC__ASSERT(0 != chain);
1184
1185         /* we assume we're already at the beginning of the file */
1186
1187         switch(seek_to_first_metadata_block_cb_(handle, read_cb, seek_cb)) {
1188                 case 0:
1189                         break;
1190                 case 1:
1191                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1192                         return false;
1193                 case 2:
1194                         chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1195                         return false;
1196                 case 3:
1197                         chain->status = FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE;
1198                         return false;
1199                 default:
1200                         FLAC__ASSERT(0);
1201                         return false;
1202         }
1203
1204         {
1205                 FLAC__int64 pos = tell_cb(handle);
1206                 if(pos < 0) {
1207                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1208                         return false;
1209                 }
1210                 chain->first_offset = (FLAC__off_t)pos;
1211         }
1212
1213         {
1214                 FLAC__bool is_last;
1215                 FLAC__MetadataType type;
1216                 unsigned length;
1217
1218                 do {
1219                         node = node_new_();
1220                         if(0 == node) {
1221                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1222                                 return false;
1223                         }
1224
1225                         if(!read_metadata_block_header_cb_(handle, read_cb, &is_last, &type, &length)) {
1226                                 node_delete_(node);
1227                                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1228                                 return false;
1229                         }
1230
1231                         node->data = FLAC__metadata_object_new(type);
1232                         if(0 == node->data) {
1233                                 node_delete_(node);
1234                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1235                                 return false;
1236                         }
1237
1238                         node->data->is_last = is_last;
1239                         node->data->length = length;
1240
1241                         chain->status = get_equivalent_status_(read_metadata_block_data_cb_(handle, read_cb, seek_cb, node->data));
1242                         if(chain->status != FLAC__METADATA_CHAIN_STATUS_OK) {
1243                                 node_delete_(node);
1244                                 return false;
1245                         }
1246                         chain_append_node_(chain, node);
1247                 } while(!is_last);
1248         }
1249
1250         {
1251                 FLAC__int64 pos = tell_cb(handle);
1252                 if(pos < 0) {
1253                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1254                         return false;
1255                 }
1256                 chain->last_offset = (FLAC__off_t)pos;
1257         }
1258
1259         chain->initial_length = chain_calculate_length_(chain);
1260
1261         return true;
1262 }
1263
1264 static FLAC__StreamDecoderReadStatus chain_read_ogg_read_cb_(const FLAC__StreamDecoder *decoder, FLAC__byte buffer[], size_t *bytes, void *client_data)
1265 {
1266         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1267         (void)decoder;
1268         if(*bytes > 0 && chain->status == FLAC__METADATA_CHAIN_STATUS_OK) {
1269                 *bytes = chain->read_cb(buffer, sizeof(FLAC__byte), *bytes, chain->handle);
1270                 if(*bytes == 0)
1271                         return FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM;
1272                 else
1273                         return FLAC__STREAM_DECODER_READ_STATUS_CONTINUE;
1274         }
1275         else
1276                 return FLAC__STREAM_DECODER_READ_STATUS_ABORT;
1277 }
1278
1279 static FLAC__StreamDecoderWriteStatus chain_read_ogg_write_cb_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
1280 {
1281         (void)decoder, (void)frame, (void)buffer, (void)client_data;
1282         return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
1283 }
1284
1285 static void chain_read_ogg_metadata_cb_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
1286 {
1287         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1288         FLAC__Metadata_Node *node;
1289
1290         (void)decoder;
1291
1292         node = node_new_();
1293         if(0 == node) {
1294                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1295                 return;
1296         }
1297
1298         node->data = FLAC__metadata_object_clone(metadata);
1299         if(0 == node->data) {
1300                 node_delete_(node);
1301                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1302                 return;
1303         }
1304
1305         chain_append_node_(chain, node);
1306 }
1307
1308 static void chain_read_ogg_error_cb_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
1309 {
1310         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1311         (void)decoder, (void)status;
1312         chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1313 }
1314
1315 static FLAC__bool chain_read_ogg_cb_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb)
1316 {
1317         FLAC__StreamDecoder *decoder;
1318
1319         FLAC__ASSERT(0 != chain);
1320
1321         /* we assume we're already at the beginning of the file */
1322
1323         chain->handle = handle;
1324         chain->read_cb = read_cb;
1325         if(0 == (decoder = FLAC__stream_decoder_new())) {
1326                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1327                 return false;
1328         }
1329         FLAC__stream_decoder_set_metadata_respond_all(decoder);
1330         if(FLAC__stream_decoder_init_ogg_stream(decoder, chain_read_ogg_read_cb_, /*seek_callback=*/0, /*tell_callback=*/0, /*length_callback=*/0, /*eof_callback=*/0, chain_read_ogg_write_cb_, chain_read_ogg_metadata_cb_, chain_read_ogg_error_cb_, chain) != FLAC__STREAM_DECODER_INIT_STATUS_OK) {
1331                 FLAC__stream_decoder_delete(decoder);
1332                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1333                 return false;
1334         }
1335
1336         chain->first_offset = 0; /*@@@ wrong; will need to be set correctly to implement metadata writing for Ogg FLAC */
1337
1338         if(!FLAC__stream_decoder_process_until_end_of_metadata(decoder))
1339                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1340         if(chain->status != FLAC__METADATA_CHAIN_STATUS_OK) {
1341                 FLAC__stream_decoder_delete(decoder);
1342                 return false;
1343         }
1344
1345         FLAC__stream_decoder_delete(decoder);
1346
1347         chain->last_offset = 0; /*@@@ wrong; will need to be set correctly to implement metadata writing for Ogg FLAC */
1348
1349         chain->initial_length = chain_calculate_length_(chain);
1350
1351         return true;
1352 }
1353
1354 static FLAC__bool chain_rewrite_metadata_in_place_cb_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, FLAC__IOCallback_Seek seek_cb)
1355 {
1356         FLAC__Metadata_Node *node;
1357
1358         FLAC__ASSERT(0 != chain);
1359         FLAC__ASSERT(0 != chain->head);
1360
1361         if(0 != seek_cb(handle, chain->first_offset, SEEK_SET)) {
1362                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1363                 return false;
1364         }
1365
1366         for(node = chain->head; node; node = node->next) {
1367                 if(!write_metadata_block_header_cb_(handle, write_cb, node->data)) {
1368                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1369                         return false;
1370                 }
1371                 if(!write_metadata_block_data_cb_(handle, write_cb, node->data)) {
1372                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1373                         return false;
1374                 }
1375         }
1376
1377         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1378
1379         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
1380         return true;
1381 }
1382
1383 static FLAC__bool chain_rewrite_metadata_in_place_(FLAC__Metadata_Chain *chain)
1384 {
1385         FILE *file;
1386         FLAC__bool ret;
1387
1388         FLAC__ASSERT(0 != chain->filename);
1389
1390         if(0 == (file = flac_fopen(chain->filename, "r+b"))) {
1391                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1392                 return false;
1393         }
1394
1395         /* chain_rewrite_metadata_in_place_cb_() sets chain->status for us */
1396         ret = chain_rewrite_metadata_in_place_cb_(chain, (FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, fseek_wrapper_);
1397
1398         fclose(file);
1399
1400         return ret;
1401 }
1402
1403 static FLAC__bool chain_rewrite_file_(FLAC__Metadata_Chain *chain, const char *tempfile_path_prefix)
1404 {
1405         FILE *f, *tempfile = NULL;
1406         char *tempfilename;
1407         FLAC__Metadata_SimpleIteratorStatus status;
1408         const FLAC__Metadata_Node *node;
1409
1410         FLAC__ASSERT(0 != chain);
1411         FLAC__ASSERT(0 != chain->filename);
1412         FLAC__ASSERT(0 != chain->head);
1413
1414         /* copy the file prefix (data up to first metadata block */
1415         if(0 == (f = flac_fopen(chain->filename, "rb"))) {
1416                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1417                 return false;
1418         }
1419         if(!open_tempfile_(chain->filename, tempfile_path_prefix, &tempfile, &tempfilename, &status)) {
1420                 chain->status = get_equivalent_status_(status);
1421                 goto err;
1422         }
1423         if(!copy_n_bytes_from_file_(f, tempfile, chain->first_offset, &status)) {
1424                 chain->status = get_equivalent_status_(status);
1425                 goto err;
1426         }
1427
1428         /* write the metadata */
1429         for(node = chain->head; node; node = node->next) {
1430                 if(!write_metadata_block_header_(tempfile, &status, node->data)) {
1431                         chain->status = get_equivalent_status_(status);
1432                         goto err;
1433                 }
1434                 if(!write_metadata_block_data_(tempfile, &status, node->data)) {
1435                         chain->status = get_equivalent_status_(status);
1436                         goto err;
1437                 }
1438         }
1439         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1440
1441         /* copy the file postfix (everything after the metadata) */
1442         if(0 != fseeko(f, chain->last_offset, SEEK_SET)) {
1443                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1444                 goto err;
1445         }
1446         if(!copy_remaining_bytes_from_file_(f, tempfile, &status)) {
1447                 chain->status = get_equivalent_status_(status);
1448                 goto err;
1449         }
1450
1451         /* move the tempfile on top of the original */
1452         (void)fclose(f);
1453         if(!transport_tempfile_(chain->filename, &tempfile, &tempfilename, &status))
1454                 return false;
1455
1456         return true;
1457
1458 err:
1459         (void)fclose(f);
1460         cleanup_tempfile_(&tempfile, &tempfilename);
1461         return false;
1462 }
1463
1464 /* assumes 'handle' is already at beginning of file */
1465 static FLAC__bool chain_rewrite_file_cb_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb, FLAC__IOCallback_Eof eof_cb, FLAC__IOHandle temp_handle, FLAC__IOCallback_Write temp_write_cb)
1466 {
1467         FLAC__Metadata_SimpleIteratorStatus status;
1468         const FLAC__Metadata_Node *node;
1469
1470         FLAC__ASSERT(0 != chain);
1471         FLAC__ASSERT(0 == chain->filename);
1472         FLAC__ASSERT(0 != chain->head);
1473
1474         /* copy the file prefix (data up to first metadata block */
1475         if(!copy_n_bytes_from_file_cb_(handle, read_cb, temp_handle, temp_write_cb, chain->first_offset, &status)) {
1476                 chain->status = get_equivalent_status_(status);
1477                 return false;
1478         }
1479
1480         /* write the metadata */
1481         for(node = chain->head; node; node = node->next) {
1482                 if(!write_metadata_block_header_cb_(temp_handle, temp_write_cb, node->data)) {
1483                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1484                         return false;
1485                 }
1486                 if(!write_metadata_block_data_cb_(temp_handle, temp_write_cb, node->data)) {
1487                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1488                         return false;
1489                 }
1490         }
1491         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1492
1493         /* copy the file postfix (everything after the metadata) */
1494         if(0 != seek_cb(handle, chain->last_offset, SEEK_SET)) {
1495                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1496                 return false;
1497         }
1498         if(!copy_remaining_bytes_from_file_cb_(handle, read_cb, eof_cb, temp_handle, temp_write_cb, &status)) {
1499                 chain->status = get_equivalent_status_(status);
1500                 return false;
1501         }
1502
1503         return true;
1504 }
1505
1506 FLAC_API FLAC__Metadata_Chain *FLAC__metadata_chain_new(void)
1507 {
1508         FLAC__Metadata_Chain *chain = calloc(1, sizeof(FLAC__Metadata_Chain));
1509
1510         if(0 != chain)
1511                 chain_init_(chain);
1512
1513         return chain;
1514 }
1515
1516 FLAC_API void FLAC__metadata_chain_delete(FLAC__Metadata_Chain *chain)
1517 {
1518         FLAC__ASSERT(0 != chain);
1519
1520         chain_clear_(chain);
1521
1522         free(chain);
1523 }
1524
1525 FLAC_API FLAC__Metadata_ChainStatus FLAC__metadata_chain_status(FLAC__Metadata_Chain *chain)
1526 {
1527         FLAC__Metadata_ChainStatus status;
1528
1529         FLAC__ASSERT(0 != chain);
1530
1531         status = chain->status;
1532         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
1533         return status;
1534 }
1535
1536 static FLAC__bool chain_read_(FLAC__Metadata_Chain *chain, const char *filename, FLAC__bool is_ogg)
1537 {
1538         FILE *file;
1539         FLAC__bool ret;
1540
1541         FLAC__ASSERT(0 != chain);
1542         FLAC__ASSERT(0 != filename);
1543
1544         chain_clear_(chain);
1545
1546         if(0 == (chain->filename = strdup(filename))) {
1547                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1548                 return false;
1549         }
1550
1551         chain->is_ogg = is_ogg;
1552
1553         if(0 == (file = flac_fopen(filename, "rb"))) {
1554                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1555                 return false;
1556         }
1557
1558         /* the function also sets chain->status for us */
1559         ret = is_ogg?
1560                 chain_read_ogg_cb_(chain, file, (FLAC__IOCallback_Read)fread) :
1561                 chain_read_cb_(chain, file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, ftell_wrapper_)
1562         ;
1563
1564         fclose(file);
1565
1566         return ret;
1567 }
1568
1569 FLAC_API FLAC__bool FLAC__metadata_chain_read(FLAC__Metadata_Chain *chain, const char *filename)
1570 {
1571         return chain_read_(chain, filename, /*is_ogg=*/false);
1572 }
1573
1574 /*@@@@add to tests*/
1575 FLAC_API FLAC__bool FLAC__metadata_chain_read_ogg(FLAC__Metadata_Chain *chain, const char *filename)
1576 {
1577         return chain_read_(chain, filename, /*is_ogg=*/true);
1578 }
1579
1580 static FLAC__bool chain_read_with_callbacks_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks, FLAC__bool is_ogg)
1581 {
1582         FLAC__bool ret;
1583
1584         FLAC__ASSERT(0 != chain);
1585
1586         chain_clear_(chain);
1587
1588         if (0 == callbacks.read || 0 == callbacks.seek || 0 == callbacks.tell) {
1589                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1590                 return false;
1591         }
1592
1593         chain->is_ogg = is_ogg;
1594
1595         /* rewind */
1596         if(0 != callbacks.seek(handle, 0, SEEK_SET)) {
1597                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1598                 return false;
1599         }
1600
1601         /* the function also sets chain->status for us */
1602         ret = is_ogg?
1603                 chain_read_ogg_cb_(chain, handle, callbacks.read) :
1604                 chain_read_cb_(chain, handle, callbacks.read, callbacks.seek, callbacks.tell)
1605         ;
1606
1607         return ret;
1608 }
1609
1610 FLAC_API FLAC__bool FLAC__metadata_chain_read_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1611 {
1612         return chain_read_with_callbacks_(chain, handle, callbacks, /*is_ogg=*/false);
1613 }
1614
1615 /*@@@@add to tests*/
1616 FLAC_API FLAC__bool FLAC__metadata_chain_read_ogg_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1617 {
1618         return chain_read_with_callbacks_(chain, handle, callbacks, /*is_ogg=*/true);
1619 }
1620
1621 typedef enum {
1622         LBS_NONE = 0,
1623         LBS_SIZE_CHANGED,
1624         LBS_BLOCK_ADDED,
1625         LBS_BLOCK_REMOVED
1626 } LastBlockState;
1627
1628 FLAC_API FLAC__bool FLAC__metadata_chain_check_if_tempfile_needed(FLAC__Metadata_Chain *chain, FLAC__bool use_padding)
1629 {
1630         /* This does all the same checks that are in chain_prepare_for_write_()
1631          * but doesn't actually alter the chain.  Make sure to update the logic
1632          * here if chain_prepare_for_write_() changes.
1633          */
1634         FLAC__off_t current_length;
1635         LastBlockState lbs_state = LBS_NONE;
1636         unsigned lbs_size = 0;
1637
1638         FLAC__ASSERT(0 != chain);
1639
1640         current_length = chain_calculate_length_(chain);
1641
1642         if(use_padding) {
1643                 const FLAC__Metadata_Node * const node = chain->tail;
1644                 /* if the metadata shrank and the last block is padding, we just extend the last padding block */
1645                 if(current_length < chain->initial_length && node->data->type == FLAC__METADATA_TYPE_PADDING) {
1646                         lbs_state = LBS_SIZE_CHANGED;
1647                         lbs_size = node->data->length + (chain->initial_length - current_length);
1648                 }
1649                 /* if the metadata shrank more than 4 bytes then there's room to add another padding block */
1650                 else if(current_length + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH <= chain->initial_length) {
1651                         lbs_state = LBS_BLOCK_ADDED;
1652                         lbs_size = chain->initial_length - (current_length + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
1653                 }
1654                 /* if the metadata grew but the last block is padding, try cutting the padding to restore the original length so we don't have to rewrite the whole file */
1655                 else if(current_length > chain->initial_length) {
1656                         const FLAC__off_t delta = current_length - chain->initial_length;
1657                         if(node->data->type == FLAC__METADATA_TYPE_PADDING) {
1658                                 /* if the delta is exactly the size of the last padding block, remove the padding block */
1659                                 if((FLAC__off_t)node->data->length + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH == delta) {
1660                                         lbs_state = LBS_BLOCK_REMOVED;
1661                                         lbs_size = 0;
1662                                 }
1663                                 /* if there is at least 'delta' bytes of padding, trim the padding down */
1664                                 else if((FLAC__off_t)node->data->length >= delta) {
1665                                         lbs_state = LBS_SIZE_CHANGED;
1666                                         lbs_size = node->data->length - delta;
1667                                 }
1668                         }
1669                 }
1670         }
1671
1672         current_length = 0;
1673         /* check sizes of all metadata blocks; reduce padding size if necessary */
1674         {
1675                 const FLAC__Metadata_Node *node;
1676                 for(node = chain->head; node; node = node->next) {
1677                         unsigned block_len = node->data->length;
1678                         if(node == chain->tail) {
1679                                 if(lbs_state == LBS_BLOCK_REMOVED)
1680                                         continue;
1681                                 else if(lbs_state == LBS_SIZE_CHANGED)
1682                                         block_len = lbs_size;
1683                         }
1684                         if(block_len >= (1u << FLAC__STREAM_METADATA_LENGTH_LEN)) {
1685                                 if(node->data->type == FLAC__METADATA_TYPE_PADDING)
1686                                         block_len = (1u << FLAC__STREAM_METADATA_LENGTH_LEN) - 1;
1687                                 else
1688                                         return false /* the return value doesn't matter */;
1689                         }
1690                         current_length += (FLAC__STREAM_METADATA_HEADER_LENGTH + block_len);
1691                 }
1692
1693                 if(lbs_state == LBS_BLOCK_ADDED) {
1694                         /* test added padding block */
1695                         unsigned block_len = lbs_size;
1696                         if(block_len >= (1u << FLAC__STREAM_METADATA_LENGTH_LEN))
1697                                 block_len = (1u << FLAC__STREAM_METADATA_LENGTH_LEN) - 1;
1698                         current_length += (FLAC__STREAM_METADATA_HEADER_LENGTH + block_len);
1699                 }
1700         }
1701
1702         return (current_length != chain->initial_length);
1703 }
1704
1705 FLAC_API FLAC__bool FLAC__metadata_chain_write(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__bool preserve_file_stats)
1706 {
1707         struct flac_stat_s stats;
1708         const char *tempfile_path_prefix = 0;
1709         FLAC__off_t current_length;
1710
1711         FLAC__ASSERT(0 != chain);
1712
1713         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1714                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1715                 return false;
1716         }
1717
1718         if (0 == chain->filename) {
1719                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1720                 return false;
1721         }
1722
1723         current_length = chain_prepare_for_write_(chain, use_padding);
1724
1725         /* a return value of 0 means there was an error; chain->status is already set */
1726         if (0 == current_length)
1727                 return false;
1728
1729         if(preserve_file_stats)
1730                 get_file_stats_(chain->filename, &stats);
1731
1732         if(current_length == chain->initial_length) {
1733                 if(!chain_rewrite_metadata_in_place_(chain))
1734                         return false;
1735         }
1736         else {
1737                 if(!chain_rewrite_file_(chain, tempfile_path_prefix))
1738                         return false;
1739
1740                 /* recompute lengths and offsets */
1741                 {
1742                         const FLAC__Metadata_Node *node;
1743                         chain->initial_length = current_length;
1744                         chain->last_offset = chain->first_offset;
1745                         for(node = chain->head; node; node = node->next)
1746                                 chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1747                 }
1748         }
1749
1750         if(preserve_file_stats)
1751                 set_file_stats_(chain->filename, &stats);
1752
1753         return true;
1754 }
1755
1756 FLAC_API FLAC__bool FLAC__metadata_chain_write_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1757 {
1758         FLAC__off_t current_length;
1759
1760         FLAC__ASSERT(0 != chain);
1761
1762         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1763                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1764                 return false;
1765         }
1766
1767         if (0 != chain->filename) {
1768                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1769                 return false;
1770         }
1771
1772         if (0 == callbacks.write || 0 == callbacks.seek) {
1773                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1774                 return false;
1775         }
1776
1777         if (FLAC__metadata_chain_check_if_tempfile_needed(chain, use_padding)) {
1778                 chain->status = FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL;
1779                 return false;
1780         }
1781
1782         current_length = chain_prepare_for_write_(chain, use_padding);
1783
1784         /* a return value of 0 means there was an error; chain->status is already set */
1785         if (0 == current_length)
1786                 return false;
1787
1788         FLAC__ASSERT(current_length == chain->initial_length);
1789
1790         return chain_rewrite_metadata_in_place_cb_(chain, handle, callbacks.write, callbacks.seek);
1791 }
1792
1793 FLAC_API FLAC__bool FLAC__metadata_chain_write_with_callbacks_and_tempfile(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks, FLAC__IOHandle temp_handle, FLAC__IOCallbacks temp_callbacks)
1794 {
1795         FLAC__off_t current_length;
1796
1797         FLAC__ASSERT(0 != chain);
1798
1799         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1800                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1801                 return false;
1802         }
1803
1804         if (0 != chain->filename) {
1805                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1806                 return false;
1807         }
1808
1809         if (0 == callbacks.read || 0 == callbacks.seek || 0 == callbacks.eof) {
1810                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1811                 return false;
1812         }
1813         if (0 == temp_callbacks.write) {
1814                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1815                 return false;
1816         }
1817
1818         if (!FLAC__metadata_chain_check_if_tempfile_needed(chain, use_padding)) {
1819                 chain->status = FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL;
1820                 return false;
1821         }
1822
1823         current_length = chain_prepare_for_write_(chain, use_padding);
1824
1825         /* a return value of 0 means there was an error; chain->status is already set */
1826         if (0 == current_length)
1827                 return false;
1828
1829         FLAC__ASSERT(current_length != chain->initial_length);
1830
1831         /* rewind */
1832         if(0 != callbacks.seek(handle, 0, SEEK_SET)) {
1833                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1834                 return false;
1835         }
1836
1837         if(!chain_rewrite_file_cb_(chain, handle, callbacks.read, callbacks.seek, callbacks.eof, temp_handle, temp_callbacks.write))
1838                 return false;
1839
1840         /* recompute lengths and offsets */
1841         {
1842                 const FLAC__Metadata_Node *node;
1843                 chain->initial_length = current_length;
1844                 chain->last_offset = chain->first_offset;
1845                 for(node = chain->head; node; node = node->next)
1846                         chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1847         }
1848
1849         return true;
1850 }
1851
1852 FLAC_API void FLAC__metadata_chain_merge_padding(FLAC__Metadata_Chain *chain)
1853 {
1854         FLAC__Metadata_Node *node;
1855
1856         FLAC__ASSERT(0 != chain);
1857
1858         for(node = chain->head; node; ) {
1859                 if(!chain_merge_adjacent_padding_(chain, node))
1860                         node = node->next;
1861         }
1862 }
1863
1864 FLAC_API void FLAC__metadata_chain_sort_padding(FLAC__Metadata_Chain *chain)
1865 {
1866         FLAC__Metadata_Node *node, *save;
1867         unsigned i;
1868
1869         FLAC__ASSERT(0 != chain);
1870
1871         /*
1872          * Don't try and be too smart... this simple algo is good enough for
1873          * the small number of nodes that we deal with.
1874          */
1875         for(i = 0, node = chain->head; i < chain->nodes; i++) {
1876                 if(node->data->type == FLAC__METADATA_TYPE_PADDING) {
1877                         save = node->next;
1878                         chain_remove_node_(chain, node);
1879                         chain_append_node_(chain, node);
1880                         node = save;
1881                 }
1882                 else {
1883                         node = node->next;
1884                 }
1885         }
1886
1887         FLAC__metadata_chain_merge_padding(chain);
1888 }
1889
1890
1891 FLAC_API FLAC__Metadata_Iterator *FLAC__metadata_iterator_new(void)
1892 {
1893         FLAC__Metadata_Iterator *iterator = calloc(1, sizeof(FLAC__Metadata_Iterator));
1894
1895         /* calloc() implies:
1896                 iterator->current = 0;
1897                 iterator->chain = 0;
1898         */
1899
1900         return iterator;
1901 }
1902
1903 FLAC_API void FLAC__metadata_iterator_delete(FLAC__Metadata_Iterator *iterator)
1904 {
1905         FLAC__ASSERT(0 != iterator);
1906
1907         free(iterator);
1908 }
1909
1910 FLAC_API void FLAC__metadata_iterator_init(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Chain *chain)
1911 {
1912         FLAC__ASSERT(0 != iterator);
1913         FLAC__ASSERT(0 != chain);
1914         FLAC__ASSERT(0 != chain->head);
1915
1916         iterator->chain = chain;
1917         iterator->current = chain->head;
1918 }
1919
1920 FLAC_API FLAC__bool FLAC__metadata_iterator_next(FLAC__Metadata_Iterator *iterator)
1921 {
1922         FLAC__ASSERT(0 != iterator);
1923
1924         if(0 == iterator->current || 0 == iterator->current->next)
1925                 return false;
1926
1927         iterator->current = iterator->current->next;
1928         return true;
1929 }
1930
1931 FLAC_API FLAC__bool FLAC__metadata_iterator_prev(FLAC__Metadata_Iterator *iterator)
1932 {
1933         FLAC__ASSERT(0 != iterator);
1934
1935         if(0 == iterator->current || 0 == iterator->current->prev)
1936                 return false;
1937
1938         iterator->current = iterator->current->prev;
1939         return true;
1940 }
1941
1942 FLAC_API FLAC__MetadataType FLAC__metadata_iterator_get_block_type(const FLAC__Metadata_Iterator *iterator)
1943 {
1944         FLAC__ASSERT(0 != iterator);
1945         FLAC__ASSERT(0 != iterator->current);
1946         FLAC__ASSERT(0 != iterator->current->data);
1947
1948         return iterator->current->data->type;
1949 }
1950
1951 FLAC_API FLAC__StreamMetadata *FLAC__metadata_iterator_get_block(FLAC__Metadata_Iterator *iterator)
1952 {
1953         FLAC__ASSERT(0 != iterator);
1954         FLAC__ASSERT(0 != iterator->current);
1955
1956         return iterator->current->data;
1957 }
1958
1959 FLAC_API FLAC__bool FLAC__metadata_iterator_set_block(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1960 {
1961         FLAC__ASSERT(0 != iterator);
1962         FLAC__ASSERT(0 != block);
1963         return FLAC__metadata_iterator_delete_block(iterator, false) && FLAC__metadata_iterator_insert_block_after(iterator, block);
1964 }
1965
1966 FLAC_API FLAC__bool FLAC__metadata_iterator_delete_block(FLAC__Metadata_Iterator *iterator, FLAC__bool replace_with_padding)
1967 {
1968         FLAC__Metadata_Node *save;
1969
1970         FLAC__ASSERT(0 != iterator);
1971         FLAC__ASSERT(0 != iterator->current);
1972
1973         if(0 == iterator->current->prev) {
1974                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1975                 return false;
1976         }
1977
1978         save = iterator->current->prev;
1979
1980         if(replace_with_padding) {
1981                 FLAC__metadata_object_delete_data(iterator->current->data);
1982                 iterator->current->data->type = FLAC__METADATA_TYPE_PADDING;
1983         }
1984         else {
1985                 chain_delete_node_(iterator->chain, iterator->current);
1986         }
1987
1988         iterator->current = save;
1989         return true;
1990 }
1991
1992 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_before(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1993 {
1994         FLAC__Metadata_Node *node;
1995
1996         FLAC__ASSERT(0 != iterator);
1997         FLAC__ASSERT(0 != iterator->current);
1998         FLAC__ASSERT(0 != block);
1999
2000         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
2001                 return false;
2002
2003         if(0 == iterator->current->prev) {
2004                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
2005                 return false;
2006         }
2007
2008         if(0 == (node = node_new_()))
2009                 return false;
2010
2011         node->data = block;
2012         iterator_insert_node_(iterator, node);
2013         iterator->current = node;
2014         return true;
2015 }
2016
2017 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_after(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
2018 {
2019         FLAC__Metadata_Node *node;
2020
2021         FLAC__ASSERT(0 != iterator);
2022         FLAC__ASSERT(0 != iterator->current);
2023         FLAC__ASSERT(0 != block);
2024
2025         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
2026                 return false;
2027
2028         if(0 == (node = node_new_()))
2029                 return false;
2030
2031         node->data = block;
2032         iterator_insert_node_after_(iterator, node);
2033         iterator->current = node;
2034         return true;
2035 }
2036
2037
2038 /****************************************************************************
2039  *
2040  * Local function definitions
2041  *
2042  ***************************************************************************/
2043
2044 void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
2045 {
2046         unsigned i;
2047
2048         b += bytes;
2049
2050         for(i = 0; i < bytes; i++) {
2051                 *(--b) = (FLAC__byte)(val & 0xff);
2052                 val >>= 8;
2053         }
2054 }
2055
2056 void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
2057 {
2058         unsigned i;
2059
2060         for(i = 0; i < bytes; i++) {
2061                 *(b++) = (FLAC__byte)(val & 0xff);
2062                 val >>= 8;
2063         }
2064 }
2065
2066 void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes)
2067 {
2068         unsigned i;
2069
2070         b += bytes;
2071
2072         for(i = 0; i < bytes; i++) {
2073                 *(--b) = (FLAC__byte)(val & 0xff);
2074                 val >>= 8;
2075         }
2076 }
2077
2078 FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes)
2079 {
2080         FLAC__uint32 ret = 0;
2081         unsigned i;
2082
2083         for(i = 0; i < bytes; i++)
2084                 ret = (ret << 8) | (FLAC__uint32)(*b++);
2085
2086         return ret;
2087 }
2088
2089 FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes)
2090 {
2091         FLAC__uint32 ret = 0;
2092         unsigned i;
2093
2094         b += bytes;
2095
2096         for(i = 0; i < bytes; i++)
2097                 ret = (ret << 8) | (FLAC__uint32)(*--b);
2098
2099         return ret;
2100 }
2101
2102 FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes)
2103 {
2104         FLAC__uint64 ret = 0;
2105         unsigned i;
2106
2107         for(i = 0; i < bytes; i++)
2108                 ret = (ret << 8) | (FLAC__uint64)(*b++);
2109
2110         return ret;
2111 }
2112
2113 FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator)
2114 {
2115         FLAC__ASSERT(0 != iterator);
2116         FLAC__ASSERT(0 != iterator->file);
2117
2118         if(!read_metadata_block_header_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, &iterator->is_last, &iterator->type, &iterator->length)) {
2119                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2120                 return false;
2121         }
2122
2123         return true;
2124 }
2125
2126 FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block)
2127 {
2128         FLAC__ASSERT(0 != iterator);
2129         FLAC__ASSERT(0 != iterator->file);
2130
2131         iterator->status = read_metadata_block_data_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, block);
2132
2133         return (iterator->status == FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK);
2134 }
2135
2136 FLAC__bool read_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__bool *is_last, FLAC__MetadataType *type, unsigned *length)
2137 {
2138         FLAC__byte raw_header[FLAC__STREAM_METADATA_HEADER_LENGTH];
2139
2140         if(read_cb(raw_header, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
2141                 return false;
2142
2143         *is_last = raw_header[0] & 0x80? true : false;
2144         *type = (FLAC__MetadataType)(raw_header[0] & 0x7f);
2145         *length = unpack_uint32_(raw_header + 1, 3);
2146
2147         /* Note that we don't check:
2148          *    if(iterator->type >= FLAC__METADATA_TYPE_UNDEFINED)
2149          * we just will read in an opaque block
2150          */
2151
2152         return true;
2153 }
2154
2155 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata *block)
2156 {
2157         switch(block->type) {
2158                 case FLAC__METADATA_TYPE_STREAMINFO:
2159                         return read_metadata_block_data_streaminfo_cb_(handle, read_cb, &block->data.stream_info);
2160                 case FLAC__METADATA_TYPE_PADDING:
2161                         return read_metadata_block_data_padding_cb_(handle, seek_cb, &block->data.padding, block->length);
2162                 case FLAC__METADATA_TYPE_APPLICATION:
2163                         return read_metadata_block_data_application_cb_(handle, read_cb, &block->data.application, block->length);
2164                 case FLAC__METADATA_TYPE_SEEKTABLE:
2165                         return read_metadata_block_data_seektable_cb_(handle, read_cb, &block->data.seek_table, block->length);
2166                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
2167                         return read_metadata_block_data_vorbis_comment_cb_(handle, read_cb, seek_cb, &block->data.vorbis_comment, block->length);
2168                 case FLAC__METADATA_TYPE_CUESHEET:
2169                         return read_metadata_block_data_cuesheet_cb_(handle, read_cb, &block->data.cue_sheet);
2170                 case FLAC__METADATA_TYPE_PICTURE:
2171                         return read_metadata_block_data_picture_cb_(handle, read_cb, &block->data.picture);
2172                 default:
2173                         return read_metadata_block_data_unknown_cb_(handle, read_cb, &block->data.unknown, block->length);
2174         }
2175 }
2176
2177 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_StreamInfo *block)
2178 {
2179         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH], *b;
2180
2181         if(read_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
2182                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2183
2184         b = buffer;
2185
2186         /* we are using hardcoded numbers for simplicity but we should
2187          * probably eventually write a bit-level unpacker and use the
2188          * _STREAMINFO_ constants.
2189          */
2190         block->min_blocksize = unpack_uint32_(b, 2); b += 2;
2191         block->max_blocksize = unpack_uint32_(b, 2); b += 2;
2192         block->min_framesize = unpack_uint32_(b, 3); b += 3;
2193         block->max_framesize = unpack_uint32_(b, 3); b += 3;
2194         block->sample_rate = (unpack_uint32_(b, 2) << 4) | ((unsigned)(b[2] & 0xf0) >> 4);
2195         block->channels = (unsigned)((b[2] & 0x0e) >> 1) + 1;
2196         block->bits_per_sample = ((((unsigned)(b[2] & 0x01)) << 4) | (((unsigned)(b[3] & 0xf0)) >> 4)) + 1;
2197         block->total_samples = (((FLAC__uint64)(b[3] & 0x0f)) << 32) | unpack_uint64_(b+4, 4);
2198         memcpy(block->md5sum, b+8, 16);
2199
2200         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2201 }
2202
2203 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata_Padding *block, unsigned block_length)
2204 {
2205         (void)block; /* nothing to do; we don't care about reading the padding bytes */
2206
2207         if(0 != seek_cb(handle, block_length, SEEK_CUR))
2208                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2209
2210         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2211 }
2212
2213 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Application *block, unsigned block_length)
2214 {
2215         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
2216
2217         if(read_cb(block->id, 1, id_bytes, handle) != id_bytes)
2218                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2219
2220         if(block_length < id_bytes)
2221                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2222
2223         block_length -= id_bytes;
2224
2225         if(block_length == 0) {
2226                 block->data = 0;
2227         }
2228         else {
2229                 if(0 == (block->data = malloc(block_length)))
2230                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2231
2232                 if(read_cb(block->data, 1, block_length, handle) != block_length)
2233                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2234         }
2235
2236         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2237 }
2238
2239 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_SeekTable *block, unsigned block_length)
2240 {
2241         unsigned i;
2242         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
2243
2244         FLAC__ASSERT(block_length % FLAC__STREAM_METADATA_SEEKPOINT_LENGTH == 0);
2245
2246         block->num_points = block_length / FLAC__STREAM_METADATA_SEEKPOINT_LENGTH;
2247
2248         if(block->num_points == 0)
2249                 block->points = 0;
2250         else if(0 == (block->points = safe_malloc_mul_2op_p(block->num_points, /*times*/sizeof(FLAC__StreamMetadata_SeekPoint))))
2251                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2252
2253         for(i = 0; i < block->num_points; i++) {
2254                 if(read_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
2255                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2256                 /* some MAGIC NUMBERs here */
2257                 block->points[i].sample_number = unpack_uint64_(buffer, 8);
2258                 block->points[i].stream_offset = unpack_uint64_(buffer+8, 8);
2259                 block->points[i].frame_samples = unpack_uint32_(buffer+16, 2);
2260         }
2261
2262         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2263 }
2264
2265 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_entry_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment_Entry *entry, unsigned max_length)
2266 {
2267         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
2268         FLAC__byte buffer[4]; /* magic number is asserted below */
2269
2270         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8 == sizeof(buffer));
2271
2272         if(max_length < entry_length_len)
2273                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA;
2274
2275         max_length -= entry_length_len;
2276         if(read_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2277                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2278         entry->length = unpack_uint32_little_endian_(buffer, entry_length_len);
2279         if(max_length < entry->length) {
2280                 entry->length = 0;
2281                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA;
2282         } else max_length -= entry->length;
2283
2284         if(0 != entry->entry)
2285                 free(entry->entry);
2286
2287         if(entry->length == 0) {
2288                 entry->entry = 0;
2289         }
2290         else {
2291                 if(0 == (entry->entry = safe_malloc_add_2op_(entry->length, /*+*/1)))
2292                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2293
2294                 if(read_cb(entry->entry, 1, entry->length, handle) != entry->length)
2295                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2296
2297                 entry->entry[entry->length] = '\0';
2298         }
2299
2300         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2301 }
2302
2303 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata_VorbisComment *block, unsigned block_length)
2304 {
2305         unsigned i;
2306         FLAC__Metadata_SimpleIteratorStatus status;
2307         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2308         FLAC__byte buffer[4]; /* magic number is asserted below */
2309
2310         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8 == sizeof(buffer));
2311
2312         status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, &(block->vendor_string), block_length);
2313         if(block_length >= 4)
2314                 block_length -= 4;
2315         if(status == FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA)
2316                 goto skip;
2317         else if(status != FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK)
2318                 return status;
2319         block_length -= block->vendor_string.length;
2320
2321         if(block_length < num_comments_len) goto skip; else block_length -= num_comments_len;
2322         if(read_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2323                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2324         block->num_comments = unpack_uint32_little_endian_(buffer, num_comments_len);
2325
2326         if(block->num_comments == 0) {
2327                 block->comments = 0;
2328         }
2329         else if(0 == (block->comments = calloc(block->num_comments, sizeof(FLAC__StreamMetadata_VorbisComment_Entry)))) {
2330                 block->num_comments = 0;
2331                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2332         }
2333
2334         for(i = 0; i < block->num_comments; i++) {
2335                 status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, block->comments + i, block_length);
2336                 if(block_length >= 4) block_length -= 4;
2337                 if(status == FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA) {
2338                         block->num_comments = i;
2339                         goto skip;
2340                 }
2341                 else if(status != FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK) return status;
2342                 block_length -= block->comments[i].length;
2343         }
2344
2345   skip:
2346         if(block_length > 0) {
2347                 /* bad metadata */
2348                 if(0 != seek_cb(handle, block_length, SEEK_CUR))
2349                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2350         }
2351
2352         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2353 }
2354
2355 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet_Track *track)
2356 {
2357         unsigned i, len;
2358         FLAC__byte buffer[32]; /* asserted below that this is big enough */
2359
2360         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2361         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2362         FLAC__ASSERT(sizeof(buffer) >= (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8);
2363
2364         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2365         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2366         if(read_cb(buffer, 1, len, handle) != len)
2367                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2368         track->offset = unpack_uint64_(buffer, len);
2369
2370         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2371         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2372         if(read_cb(buffer, 1, len, handle) != len)
2373                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2374         track->number = (FLAC__byte)unpack_uint32_(buffer, len);
2375
2376         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2377         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2378         if(read_cb(track->isrc, 1, len, handle) != len)
2379                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2380
2381         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) % 8 == 0);
2382         len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2383         if(read_cb(buffer, 1, len, handle) != len)
2384                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2385         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN == 1);
2386         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN == 1);
2387         track->type = buffer[0] >> 7;
2388         track->pre_emphasis = (buffer[0] >> 6) & 1;
2389
2390         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2391         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2392         if(read_cb(buffer, 1, len, handle) != len)
2393                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2394         track->num_indices = (FLAC__byte)unpack_uint32_(buffer, len);
2395
2396         if(track->num_indices == 0) {
2397                 track->indices = 0;
2398         }
2399         else if(0 == (track->indices = calloc(track->num_indices, sizeof(FLAC__StreamMetadata_CueSheet_Index))))
2400                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2401
2402         for(i = 0; i < track->num_indices; i++) {
2403                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2404                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2405                 if(read_cb(buffer, 1, len, handle) != len)
2406                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2407                 track->indices[i].offset = unpack_uint64_(buffer, len);
2408
2409                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2410                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2411                 if(read_cb(buffer, 1, len, handle) != len)
2412                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2413                 track->indices[i].number = (FLAC__byte)unpack_uint32_(buffer, len);
2414
2415                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2416                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2417                 if(read_cb(buffer, 1, len, handle) != len)
2418                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2419         }
2420
2421         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2422 }
2423
2424 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet *block)
2425 {
2426         unsigned i, len;
2427         FLAC__Metadata_SimpleIteratorStatus status;
2428         FLAC__byte buffer[1024]; /* MSVC needs a constant expression so we put a magic number and assert */
2429
2430         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN)/8 <= sizeof(buffer));
2431         FLAC__ASSERT(sizeof(FLAC__uint64) <= sizeof(buffer));
2432
2433         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2434         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2435         if(read_cb(block->media_catalog_number, 1, len, handle) != len)
2436                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2437
2438         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2439         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2440         if(read_cb(buffer, 1, len, handle) != len)
2441                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2442         block->lead_in = unpack_uint64_(buffer, len);
2443
2444         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2445         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2446         if(read_cb(buffer, 1, len, handle) != len)
2447                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2448         block->is_cd = buffer[0]&0x80? true : false;
2449
2450         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2451         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2452         if(read_cb(buffer, 1, len, handle) != len)
2453                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2454         block->num_tracks = unpack_uint32_(buffer, len);
2455
2456         if(block->num_tracks == 0) {
2457                 block->tracks = 0;
2458         }
2459         else if(0 == (block->tracks = calloc(block->num_tracks, sizeof(FLAC__StreamMetadata_CueSheet_Track))))
2460                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2461
2462         for(i = 0; i < block->num_tracks; i++) {
2463                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_cuesheet_track_cb_(handle, read_cb, block->tracks + i)))
2464                         return status;
2465         }
2466
2467         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2468 }
2469
2470 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_picture_cstring_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__byte **data, FLAC__uint32 *length, FLAC__uint32 length_len)
2471 {
2472         FLAC__byte buffer[sizeof(FLAC__uint32)];
2473
2474         FLAC__ASSERT(0 != data);
2475         FLAC__ASSERT(length_len%8 == 0);
2476
2477         length_len /= 8; /* convert to bytes */
2478
2479         FLAC__ASSERT(sizeof(buffer) >= length_len);
2480
2481         if(read_cb(buffer, 1, length_len, handle) != length_len)
2482                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2483         *length = unpack_uint32_(buffer, length_len);
2484
2485         if(0 != *data)
2486                 free(*data);
2487
2488         if(0 == (*data = safe_malloc_add_2op_(*length, /*+*/1)))
2489                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2490
2491         if(*length > 0) {
2492                 if(read_cb(*data, 1, *length, handle) != *length)
2493                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2494         }
2495
2496         (*data)[*length] = '\0';
2497
2498         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2499 }
2500
2501 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Picture *block)
2502 {
2503         FLAC__Metadata_SimpleIteratorStatus status;
2504         FLAC__byte buffer[4]; /* asserted below that this is big enough */
2505         FLAC__uint32 len;
2506
2507         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8);
2508         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8);
2509         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8);
2510         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8);
2511         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8);
2512
2513         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_TYPE_LEN % 8 == 0);
2514         len = FLAC__STREAM_METADATA_PICTURE_TYPE_LEN / 8;
2515         if(read_cb(buffer, 1, len, handle) != len)
2516                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2517         block->type = (FLAC__StreamMetadata_Picture_Type)unpack_uint32_(buffer, len);
2518
2519         if((status = read_metadata_block_data_picture_cstring_cb_(handle, read_cb, (FLAC__byte**)(&(block->mime_type)), &len, FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN)) != FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK)
2520                 return status;
2521
2522         if((status = read_metadata_block_data_picture_cstring_cb_(handle, read_cb, &(block->description), &len, FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN)) != FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK)
2523                 return status;
2524
2525         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN % 8 == 0);
2526         len = FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN / 8;
2527         if(read_cb(buffer, 1, len, handle) != len)
2528                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2529         block->width = unpack_uint32_(buffer, len);
2530
2531         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN % 8 == 0);
2532         len = FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN / 8;
2533         if(read_cb(buffer, 1, len, handle) != len)
2534                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2535         block->height = unpack_uint32_(buffer, len);
2536
2537         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN % 8 == 0);
2538         len = FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN / 8;
2539         if(read_cb(buffer, 1, len, handle) != len)
2540                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2541         block->depth = unpack_uint32_(buffer, len);
2542
2543         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_COLORS_LEN % 8 == 0);
2544         len = FLAC__STREAM_METADATA_PICTURE_COLORS_LEN / 8;
2545         if(read_cb(buffer, 1, len, handle) != len)
2546                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2547         block->colors = unpack_uint32_(buffer, len);
2548
2549         /* for convenience we use read_metadata_block_data_picture_cstring_cb_() even though it adds an extra terminating NUL we don't use */
2550         if((status = read_metadata_block_data_picture_cstring_cb_(handle, read_cb, &(block->data), &(block->data_length), FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN)) != FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK)
2551                 return status;
2552
2553         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2554 }
2555
2556 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2557 {
2558         if(block_length == 0) {
2559                 block->data = 0;
2560         }
2561         else {
2562                 if(0 == (block->data = malloc(block_length)))
2563                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2564
2565                 if(read_cb(block->data, 1, block_length, handle) != block_length)
2566                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2567         }
2568
2569         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2570 }
2571
2572 FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2573 {
2574         FLAC__ASSERT(0 != file);
2575         FLAC__ASSERT(0 != status);
2576
2577         if(!write_metadata_block_header_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2578                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2579                 return false;
2580         }
2581
2582         return true;
2583 }
2584
2585 FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2586 {
2587         FLAC__ASSERT(0 != file);
2588         FLAC__ASSERT(0 != status);
2589
2590         if (write_metadata_block_data_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2591                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2592                 return true;
2593         }
2594         else {
2595                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2596                 return false;
2597         }
2598 }
2599
2600 FLAC__bool write_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2601 {
2602         FLAC__byte buffer[FLAC__STREAM_METADATA_HEADER_LENGTH];
2603
2604         FLAC__ASSERT(block->length < (1u << FLAC__STREAM_METADATA_LENGTH_LEN));
2605         /* double protection */
2606         if(block->length >= (1u << FLAC__STREAM_METADATA_LENGTH_LEN))
2607                 return false;
2608
2609         buffer[0] = (block->is_last? 0x80 : 0) | (FLAC__byte)block->type;
2610         pack_uint32_(block->length, buffer + 1, 3);
2611
2612         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
2613                 return false;
2614
2615         return true;
2616 }
2617
2618 FLAC__bool write_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2619 {
2620         FLAC__ASSERT(0 != block);
2621
2622         switch(block->type) {
2623                 case FLAC__METADATA_TYPE_STREAMINFO:
2624                         return write_metadata_block_data_streaminfo_cb_(handle, write_cb, &block->data.stream_info);
2625                 case FLAC__METADATA_TYPE_PADDING:
2626                         return write_metadata_block_data_padding_cb_(handle, write_cb, &block->data.padding, block->length);
2627                 case FLAC__METADATA_TYPE_APPLICATION:
2628                         return write_metadata_block_data_application_cb_(handle, write_cb, &block->data.application, block->length);
2629                 case FLAC__METADATA_TYPE_SEEKTABLE:
2630                         return write_metadata_block_data_seektable_cb_(handle, write_cb, &block->data.seek_table);
2631                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
2632                         return write_metadata_block_data_vorbis_comment_cb_(handle, write_cb, &block->data.vorbis_comment);
2633                 case FLAC__METADATA_TYPE_CUESHEET:
2634                         return write_metadata_block_data_cuesheet_cb_(handle, write_cb, &block->data.cue_sheet);
2635                 case FLAC__METADATA_TYPE_PICTURE:
2636                         return write_metadata_block_data_picture_cb_(handle, write_cb, &block->data.picture);
2637                 default:
2638                         return write_metadata_block_data_unknown_cb_(handle, write_cb, &block->data.unknown, block->length);
2639         }
2640 }
2641
2642 FLAC__bool write_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_StreamInfo *block)
2643 {
2644         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH];
2645         const unsigned channels1 = block->channels - 1;
2646         const unsigned bps1 = block->bits_per_sample - 1;
2647
2648         /* we are using hardcoded numbers for simplicity but we should
2649          * probably eventually write a bit-level packer and use the
2650          * _STREAMINFO_ constants.
2651          */
2652         pack_uint32_(block->min_blocksize, buffer, 2);
2653         pack_uint32_(block->max_blocksize, buffer+2, 2);
2654         pack_uint32_(block->min_framesize, buffer+4, 3);
2655         pack_uint32_(block->max_framesize, buffer+7, 3);
2656         buffer[10] = (block->sample_rate >> 12) & 0xff;
2657         buffer[11] = (block->sample_rate >> 4) & 0xff;
2658         buffer[12] = ((block->sample_rate & 0x0f) << 4) | (channels1 << 1) | (bps1 >> 4);
2659         buffer[13] = (FLAC__byte)(((bps1 & 0x0f) << 4) | ((block->total_samples >> 32) & 0x0f));
2660         pack_uint32_((FLAC__uint32)block->total_samples, buffer+14, 4);
2661         memcpy(buffer+18, block->md5sum, 16);
2662
2663         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
2664                 return false;
2665
2666         return true;
2667 }
2668
2669 FLAC__bool write_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Padding *block, unsigned block_length)
2670 {
2671         unsigned i, n = block_length;
2672         FLAC__byte buffer[1024];
2673
2674         (void)block;
2675
2676         memset(buffer, 0, 1024);
2677
2678         for(i = 0; i < n/1024; i++)
2679                 if(write_cb(buffer, 1, 1024, handle) != 1024)
2680                         return false;
2681
2682         n %= 1024;
2683
2684         if(write_cb(buffer, 1, n, handle) != n)
2685                 return false;
2686
2687         return true;
2688 }
2689
2690 FLAC__bool write_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Application *block, unsigned block_length)
2691 {
2692         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
2693
2694         if(write_cb(block->id, 1, id_bytes, handle) != id_bytes)
2695                 return false;
2696
2697         block_length -= id_bytes;
2698
2699         if(write_cb(block->data, 1, block_length, handle) != block_length)
2700                 return false;
2701
2702         return true;
2703 }
2704
2705 FLAC__bool write_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_SeekTable *block)
2706 {
2707         unsigned i;
2708         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
2709
2710         for(i = 0; i < block->num_points; i++) {
2711                 /* some MAGIC NUMBERs here */
2712                 pack_uint64_(block->points[i].sample_number, buffer, 8);
2713                 pack_uint64_(block->points[i].stream_offset, buffer+8, 8);
2714                 pack_uint32_(block->points[i].frame_samples, buffer+16, 2);
2715                 if(write_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
2716                         return false;
2717         }
2718
2719         return true;
2720 }
2721
2722 FLAC__bool write_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_VorbisComment *block)
2723 {
2724         unsigned i;
2725         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
2726         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2727         FLAC__byte buffer[4]; /* magic number is asserted below */
2728
2729         FLAC__ASSERT(flac_max(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN, FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN) / 8 == sizeof(buffer));
2730
2731         pack_uint32_little_endian_(block->vendor_string.length, buffer, entry_length_len);
2732         if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2733                 return false;
2734         if(write_cb(block->vendor_string.entry, 1, block->vendor_string.length, handle) != block->vendor_string.length)
2735                 return false;
2736
2737         pack_uint32_little_endian_(block->num_comments, buffer, num_comments_len);
2738         if(write_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2739                 return false;
2740
2741         for(i = 0; i < block->num_comments; i++) {
2742                 pack_uint32_little_endian_(block->comments[i].length, buffer, entry_length_len);
2743                 if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2744                         return false;
2745                 if(write_cb(block->comments[i].entry, 1, block->comments[i].length, handle) != block->comments[i].length)
2746                         return false;
2747         }
2748
2749         return true;
2750 }
2751
2752 FLAC__bool write_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_CueSheet *block)
2753 {
2754         unsigned i, j, len;
2755         FLAC__byte buffer[1024]; /* asserted below that this is big enough */
2756
2757         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2758         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN/8);
2759         FLAC__ASSERT(sizeof(buffer) >= (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN)/8);
2760         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2761
2762         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2763         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2764         if(write_cb(block->media_catalog_number, 1, len, handle) != len)
2765                 return false;
2766
2767         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2768         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2769         pack_uint64_(block->lead_in, buffer, len);
2770         if(write_cb(buffer, 1, len, handle) != len)
2771                 return false;
2772
2773         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2774         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2775         memset(buffer, 0, len);
2776         if(block->is_cd)
2777                 buffer[0] |= 0x80;
2778         if(write_cb(buffer, 1, len, handle) != len)
2779                 return false;
2780
2781         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2782         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2783         pack_uint32_(block->num_tracks, buffer, len);
2784         if(write_cb(buffer, 1, len, handle) != len)
2785                 return false;
2786
2787         for(i = 0; i < block->num_tracks; i++) {
2788                 FLAC__StreamMetadata_CueSheet_Track *track = block->tracks + i;
2789
2790                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2791                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2792                 pack_uint64_(track->offset, buffer, len);
2793                 if(write_cb(buffer, 1, len, handle) != len)
2794                         return false;
2795
2796                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2797                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2798                 pack_uint32_(track->number, buffer, len);
2799                 if(write_cb(buffer, 1, len, handle) != len)
2800                         return false;
2801
2802                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2803                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2804                 if(write_cb(track->isrc, 1, len, handle) != len)
2805                         return false;
2806
2807                 FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) % 8 == 0);
2808                 len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2809                 memset(buffer, 0, len);
2810                 buffer[0] = (track->type << 7) | (track->pre_emphasis << 6);
2811                 if(write_cb(buffer, 1, len, handle) != len)
2812                         return false;
2813
2814                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2815                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2816                 pack_uint32_(track->num_indices, buffer, len);
2817                 if(write_cb(buffer, 1, len, handle) != len)
2818                         return false;
2819
2820                 for(j = 0; j < track->num_indices; j++) {
2821                         FLAC__StreamMetadata_CueSheet_Index *indx = track->indices + j;
2822
2823                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2824                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2825                         pack_uint64_(indx->offset, buffer, len);
2826                         if(write_cb(buffer, 1, len, handle) != len)
2827                                 return false;
2828
2829                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2830                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2831                         pack_uint32_(indx->number, buffer, len);
2832                         if(write_cb(buffer, 1, len, handle) != len)
2833                                 return false;
2834
2835                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2836                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2837                         memset(buffer, 0, len);
2838                         if(write_cb(buffer, 1, len, handle) != len)
2839                                 return false;
2840                 }
2841         }
2842
2843         return true;
2844 }
2845
2846 FLAC__bool write_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Picture *block)
2847 {
2848         unsigned len;
2849         size_t slen;
2850         FLAC__byte buffer[4]; /* magic number is asserted below */
2851
2852         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_TYPE_LEN%8);
2853         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN%8);
2854         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN%8);
2855         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN%8);
2856         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN%8);
2857         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN%8);
2858         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_COLORS_LEN%8);
2859         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN%8);
2860         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8);
2861         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN/8);
2862         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN/8);
2863         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8);
2864         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8);
2865         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8);
2866         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8);
2867         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN/8);
2868
2869         len = FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8;
2870         pack_uint32_(block->type, buffer, len);
2871         if(write_cb(buffer, 1, len, handle) != len)
2872                 return false;
2873
2874         len = FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN/8;
2875         slen = strlen(block->mime_type);
2876         pack_uint32_(slen, buffer, len);
2877         if(write_cb(buffer, 1, len, handle) != len)
2878                 return false;
2879         if(write_cb(block->mime_type, 1, slen, handle) != slen)
2880                 return false;
2881
2882         len = FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN/8;
2883         slen = strlen((const char *)block->description);
2884         pack_uint32_(slen, buffer, len);
2885         if(write_cb(buffer, 1, len, handle) != len)
2886                 return false;
2887         if(write_cb(block->description, 1, slen, handle) != slen)
2888                 return false;
2889
2890         len = FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8;
2891         pack_uint32_(block->width, buffer, len);
2892         if(write_cb(buffer, 1, len, handle) != len)
2893                 return false;
2894
2895         len = FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8;
2896         pack_uint32_(block->height, buffer, len);
2897         if(write_cb(buffer, 1, len, handle) != len)
2898                 return false;
2899
2900         len = FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8;
2901         pack_uint32_(block->depth, buffer, len);
2902         if(write_cb(buffer, 1, len, handle) != len)
2903                 return false;
2904
2905         len = FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8;
2906         pack_uint32_(block->colors, buffer, len);
2907         if(write_cb(buffer, 1, len, handle) != len)
2908                 return false;
2909
2910         len = FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN/8;
2911         pack_uint32_(block->data_length, buffer, len);
2912         if(write_cb(buffer, 1, len, handle) != len)
2913                 return false;
2914         if(write_cb(block->data, 1, block->data_length, handle) != block->data_length)
2915                 return false;
2916
2917         return true;
2918 }
2919
2920 FLAC__bool write_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2921 {
2922         if(write_cb(block->data, 1, block_length, handle) != block_length)
2923                 return false;
2924
2925         return true;
2926 }
2927
2928 FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block)
2929 {
2930         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2931                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2932                 return false;
2933         }
2934
2935         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2936                 return false;
2937
2938         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2939                 return false;
2940
2941         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2942                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2943                 return false;
2944         }
2945
2946         return read_metadata_block_header_(iterator);
2947 }
2948
2949 FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last)
2950 {
2951         FLAC__StreamMetadata *padding;
2952
2953         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2954                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2955                 return false;
2956         }
2957
2958         block->is_last = false;
2959
2960         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2961                 return false;
2962
2963         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2964                 return false;
2965
2966         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING)))
2967                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2968
2969         padding->is_last = padding_is_last;
2970         padding->length = padding_length;
2971
2972         if(!write_metadata_block_header_(iterator->file, &iterator->status, padding)) {
2973                 FLAC__metadata_object_delete(padding);
2974                 return false;
2975         }
2976
2977         if(!write_metadata_block_data_(iterator->file, &iterator->status, padding)) {
2978                 FLAC__metadata_object_delete(padding);
2979                 return false;
2980         }
2981
2982         FLAC__metadata_object_delete(padding);
2983
2984         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2985                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2986                 return false;
2987         }
2988
2989         return read_metadata_block_header_(iterator);
2990 }
2991
2992 FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append)
2993 {
2994         FILE *tempfile = NULL;
2995         char *tempfilename = NULL;
2996         int fixup_is_last_code = 0; /* 0 => no need to change any is_last flags */
2997         FLAC__off_t fixup_is_last_flag_offset = -1;
2998
2999         FLAC__ASSERT(0 != block || append == false);
3000
3001         if(iterator->is_last) {
3002                 if(append) {
3003                         fixup_is_last_code = 1; /* 1 => clear the is_last flag at the following offset */
3004                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
3005                 }
3006                 else if(0 == block) {
3007                         simple_iterator_push_(iterator);
3008                         if(!FLAC__metadata_simple_iterator_prev(iterator)) {
3009                                 (void)simple_iterator_pop_(iterator);
3010                                 return false;
3011                         }
3012                         fixup_is_last_code = -1; /* -1 => set the is_last the flag at the following offset */
3013                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
3014                         if(!simple_iterator_pop_(iterator))
3015                                 return false;
3016                 }
3017         }
3018
3019         if(!simple_iterator_copy_file_prefix_(iterator, &tempfile, &tempfilename, append))
3020                 return false;
3021
3022         if(0 != block) {
3023                 if(!write_metadata_block_header_(tempfile, &iterator->status, block)) {
3024                         cleanup_tempfile_(&tempfile, &tempfilename);
3025                         return false;
3026                 }
3027
3028                 if(!write_metadata_block_data_(tempfile, &iterator->status, block)) {
3029                         cleanup_tempfile_(&tempfile, &tempfilename);
3030                         return false;
3031                 }
3032         }
3033
3034         if(!simple_iterator_copy_file_postfix_(iterator, &tempfile, &tempfilename, fixup_is_last_code, fixup_is_last_flag_offset, block==0))
3035                 return false;
3036
3037         if(append)
3038                 return FLAC__metadata_simple_iterator_next(iterator);
3039
3040         return true;
3041 }
3042
3043 void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator)
3044 {
3045         FLAC__ASSERT(iterator->depth+1 < SIMPLE_ITERATOR_MAX_PUSH_DEPTH);
3046         iterator->offset[iterator->depth+1] = iterator->offset[iterator->depth];
3047         iterator->depth++;
3048 }
3049
3050 FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator)
3051 {
3052         FLAC__ASSERT(iterator->depth > 0);
3053         iterator->depth--;
3054         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
3055                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3056                 return false;
3057         }
3058
3059         return read_metadata_block_header_(iterator);
3060 }
3061
3062 /* return meanings:
3063  * 0: ok
3064  * 1: read error
3065  * 2: seek error
3066  * 3: not a FLAC file
3067  */
3068 unsigned seek_to_first_metadata_block_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb)
3069 {
3070         FLAC__byte buffer[4];
3071         size_t n;
3072         unsigned i;
3073
3074         FLAC__ASSERT(FLAC__STREAM_SYNC_LENGTH == sizeof(buffer));
3075
3076         /* skip any id3v2 tag */
3077         errno = 0;
3078         n = read_cb(buffer, 1, 4, handle);
3079         if(errno)
3080                 return 1;
3081         else if(n != 4)
3082                 return 3;
3083         else if(0 == memcmp(buffer, "ID3", 3)) {
3084                 unsigned tag_length = 0;
3085
3086                 /* skip to the tag length */
3087                 if(seek_cb(handle, 2, SEEK_CUR) < 0)
3088                         return 2;
3089
3090                 /* read the length */
3091                 for(i = 0; i < 4; i++) {
3092                         if(read_cb(buffer, 1, 1, handle) < 1 || buffer[0] & 0x80)
3093                                 return 1;
3094                         tag_length <<= 7;
3095                         tag_length |= (buffer[0] & 0x7f);
3096                 }
3097
3098                 /* skip the rest of the tag */
3099                 if(seek_cb(handle, tag_length, SEEK_CUR) < 0)
3100                         return 2;
3101
3102                 /* read the stream sync code */
3103                 errno = 0;
3104                 n = read_cb(buffer, 1, 4, handle);
3105                 if(errno)
3106                         return 1;
3107                 else if(n != 4)
3108                         return 3;
3109         }
3110
3111         /* check for the fLaC signature */
3112         if(0 == memcmp(FLAC__STREAM_SYNC_STRING, buffer, FLAC__STREAM_SYNC_LENGTH))
3113                 return 0;
3114         else
3115                 return 3;
3116 }
3117
3118 unsigned seek_to_first_metadata_block_(FILE *f)
3119 {
3120         return seek_to_first_metadata_block_cb_((FLAC__IOHandle)f, (FLAC__IOCallback_Read)fread, fseek_wrapper_);
3121 }
3122
3123 FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append)
3124 {
3125         const FLAC__off_t offset_end = append? iterator->offset[iterator->depth] + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (FLAC__off_t)iterator->length : iterator->offset[iterator->depth];
3126
3127         if(0 != fseeko(iterator->file, 0, SEEK_SET)) {
3128                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3129                 return false;
3130         }
3131         if(!open_tempfile_(iterator->filename, iterator->tempfile_path_prefix, tempfile, tempfilename, &iterator->status)) {
3132                 cleanup_tempfile_(tempfile, tempfilename);
3133                 return false;
3134         }
3135         if(!copy_n_bytes_from_file_(iterator->file, *tempfile, offset_end, &iterator->status)) {
3136                 cleanup_tempfile_(tempfile, tempfilename);
3137                 return false;
3138         }
3139
3140         return true;
3141 }
3142
3143 FLAC__bool simple_iterator_copy_file_postfix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, int fixup_is_last_code, FLAC__off_t fixup_is_last_flag_offset, FLAC__bool backup)
3144 {
3145         FLAC__off_t save_offset = iterator->offset[iterator->depth];
3146         FLAC__ASSERT(0 != *tempfile);
3147
3148         if(0 != fseeko(iterator->file, save_offset + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (FLAC__off_t)iterator->length, SEEK_SET)) {
3149                 cleanup_tempfile_(tempfile, tempfilename);
3150                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3151                 return false;
3152         }
3153         if(!copy_remaining_bytes_from_file_(iterator->file, *tempfile, &iterator->status)) {
3154                 cleanup_tempfile_(tempfile, tempfilename);
3155                 return false;
3156         }
3157
3158         if(fixup_is_last_code != 0) {
3159                 /*
3160                  * if code == 1, it means a block was appended to the end so
3161                  *   we have to clear the is_last flag of the previous block
3162                  * if code == -1, it means the last block was deleted so
3163                  *   we have to set the is_last flag of the previous block
3164                  */
3165                 /* MAGIC NUMBERs here; we know the is_last flag is the high bit of the byte at this location */
3166                 FLAC__byte x;
3167                 if(0 != fseeko(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
3168                         cleanup_tempfile_(tempfile, tempfilename);
3169                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3170                         return false;
3171                 }
3172                 if(fread(&x, 1, 1, *tempfile) != 1) {
3173                         cleanup_tempfile_(tempfile, tempfilename);
3174                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3175                         return false;
3176                 }
3177                 if(fixup_is_last_code > 0) {
3178                         FLAC__ASSERT(x & 0x80);
3179                         x &= 0x7f;
3180                 }
3181                 else {
3182                         FLAC__ASSERT(!(x & 0x80));
3183                         x |= 0x80;
3184                 }
3185                 if(0 != fseeko(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
3186                         cleanup_tempfile_(tempfile, tempfilename);
3187                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3188                         return false;
3189                 }
3190                 if(local__fwrite(&x, 1, 1, *tempfile) != 1) {
3191                         cleanup_tempfile_(tempfile, tempfilename);
3192                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3193                         return false;
3194                 }
3195         }
3196
3197         (void)fclose(iterator->file);
3198
3199         if(!transport_tempfile_(iterator->filename, tempfile, tempfilename, &iterator->status))
3200                 return false;
3201
3202         if(iterator->has_stats)
3203                 set_file_stats_(iterator->filename, &iterator->stats);
3204
3205         if(!simple_iterator_prime_input_(iterator, !iterator->is_writable))
3206                 return false;
3207         if(backup) {
3208                 while(iterator->offset[iterator->depth] + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (FLAC__off_t)iterator->length < save_offset)
3209                         if(!FLAC__metadata_simple_iterator_next(iterator))
3210                                 return false;
3211                 return true;
3212         }
3213         else {
3214                 /* move the iterator to it's original block faster by faking a push, then doing a pop_ */
3215                 FLAC__ASSERT(iterator->depth == 0);
3216                 iterator->offset[0] = save_offset;
3217                 iterator->depth++;
3218                 return simple_iterator_pop_(iterator);
3219         }
3220 }
3221
3222 FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status)
3223 {
3224         FLAC__byte buffer[8192];
3225         size_t n;
3226
3227         FLAC__ASSERT(bytes >= 0);
3228         while(bytes > 0) {
3229                 n = flac_min(sizeof(buffer), (size_t)bytes);
3230                 if(fread(buffer, 1, n, file) != n) {
3231                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3232                         return false;
3233                 }
3234                 if(local__fwrite(buffer, 1, n, tempfile) != n) {
3235                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3236                         return false;
3237                 }
3238                 bytes -= n;
3239         }
3240
3241         return true;
3242 }
3243
3244 FLAC__bool copy_n_bytes_from_file_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOHandle temp_handle, FLAC__IOCallback_Write temp_write_cb, FLAC__off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status)
3245 {
3246         FLAC__byte buffer[8192];
3247         size_t n;
3248
3249         FLAC__ASSERT(bytes >= 0);
3250         while(bytes > 0) {
3251                 n = flac_min(sizeof(buffer), (size_t)bytes);
3252                 if(read_cb(buffer, 1, n, handle) != n) {
3253                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3254                         return false;
3255                 }
3256                 if(temp_write_cb(buffer, 1, n, temp_handle) != n) {
3257                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3258                         return false;
3259                 }
3260                 bytes -= n;
3261         }
3262
3263         return true;
3264 }
3265
3266 FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status)
3267 {
3268         FLAC__byte buffer[8192];
3269         size_t n;
3270
3271         while(!feof(file)) {
3272                 n = fread(buffer, 1, sizeof(buffer), file);
3273                 if(n == 0 && !feof(file)) {
3274                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3275                         return false;
3276                 }
3277                 if(n > 0 && local__fwrite(buffer, 1, n, tempfile) != n) {
3278                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3279                         return false;
3280                 }
3281         }
3282
3283         return true;
3284 }
3285
3286 FLAC__bool copy_remaining_bytes_from_file_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Eof eof_cb, FLAC__IOHandle temp_handle, FLAC__IOCallback_Write temp_write_cb, FLAC__Metadata_SimpleIteratorStatus *status)
3287 {
3288         FLAC__byte buffer[8192];
3289         size_t n;
3290
3291         while(!eof_cb(handle)) {
3292                 n = read_cb(buffer, 1, sizeof(buffer), handle);
3293                 if(n == 0 && !eof_cb(handle)) {
3294                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3295                         return false;
3296                 }
3297                 if(n > 0 && temp_write_cb(buffer, 1, n, temp_handle) != n) {
3298                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3299                         return false;
3300                 }
3301         }
3302