src/libFLAC/metadata_iterators.c

   1 /* libFLAC - Free Lossless Audio Codec library
   2  * Copyright (C) 2001,2002,2003,2004,2005,2006,2007  Josh Coalson
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  * - Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *
  11  * - Redistributions in binary form must reproduce the above copyright
  12  * notice, this list of conditions and the following disclaimer in the
  13  * documentation and/or other materials provided with the distribution.
  14  *
  15  * - Neither the name of the Xiph.org Foundation nor the names of its
  16  * contributors may be used to endorse or promote products derived from
  17  * this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  22  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
  23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  26  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  27  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  28  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  29  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 #if HAVE_CONFIG_H
  33 #  include <config.h>
  34 #endif
  35
  36 #include <errno.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40
  41 #if defined _MSC_VER || defined __BORLANDC__ || defined __MINGW32__
  42 #if defined __BORLANDC__
  43 #include <utime.h> /* for utime() */
  44 #else
  45 #include <sys/utime.h> /* for utime() */
  46 #endif
  47 #include <io.h> /* for chmod() */
  48 #include <sys/types.h> /* for off_t */
  49 #if _MSC_VER <= 1600 || defined __BORLANDC__ /* @@@ [2G limit] */
  50 #define fseeko fseek
  51 #define ftello ftell
  52 #endif
  53 #else
  54 #include <sys/types.h> /* some flavors of BSD (like OS X) require this to get time_t */
  55 #include <utime.h> /* for utime() */
  56 #include <unistd.h> /* for chown(), unlink() */
  57 #endif
  58 #include <sys/stat.h> /* for stat(), maybe chmod() */
  59
  60 #include "private/metadata.h"
  61
  62 #include "FLAC/assert.h"
  63 #include "FLAC/stream_decoder.h"
  64
  65 #ifdef max
  66 #undef max
  67 #endif
  68 #define max(a,b) ((a)>(b)?(a):(b))
  69 #ifdef min
  70 #undef min
  71 #endif
  72 #define min(a,b) ((a)<(b)?(a):(b))
  73
  74
  75 /****************************************************************************
  76  *
  77  * Local function declarations
  78  *
  79  ***************************************************************************/
  80
  81 static void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes);
  82 static void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes);
  83 static void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes);
  84 static FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes);
  85 static FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes);
  86 static FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes);
  87
  88 static FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator);
  89 static FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block);
  90 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);
  91 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);
  92 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_StreamInfo *block);
  93 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);
  94 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);
  95 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);
  96 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);
  97 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment *block);
  98 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet_Track *track);
  99 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet *block);
 100 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Picture *block);
 101 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);
 102
 103 static FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block);
 104 static FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block);
 105 static FLAC__bool write_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block);
 106 static FLAC__bool write_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block);
 107 static FLAC__bool write_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_StreamInfo *block);
 108 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);
 109 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);
 110 static FLAC__bool write_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_SeekTable *block);
 111 static FLAC__bool write_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_VorbisComment *block);
 112 static FLAC__bool write_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_CueSheet *block);
 113 static FLAC__bool write_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Picture *block);
 114 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);
 115
 116 static FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block);
 117 static FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last);
 118 static FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append);
 119
 120 static void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator);
 121 static FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator);
 122
 123 static unsigned seek_to_first_metadata_block_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb);
 124 static unsigned seek_to_first_metadata_block_(FILE *f);
 125
 126 static FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append);
 127 static FLAC__bool simple_iterator_copy_file_postfix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, int fixup_is_last_code, off_t fixup_is_last_flag_offset, FLAC__bool backup);
 128
 129 static FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status);
 130 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, off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status);
 131 static FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status);
 132 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);
 133
 134 static FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status);
 135 static FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status);
 136 static void cleanup_tempfile_(FILE **tempfile, char **tempfilename);
 137
 138 static FLAC__bool get_file_stats_(const char *filename, struct stat *stats);
 139 static void set_file_stats_(const char *filename, struct stat *stats);
 140
 141 static int fseek_wrapper_(FLAC__IOHandle handle, FLAC__int64 offset, int whence);
 142 static FLAC__int64 ftell_wrapper_(FLAC__IOHandle handle);
 143
 144 static FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status);
 145
 146
 147 #ifdef FLAC__VALGRIND_TESTING
 148 static size_t local__fwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream)
 149 {
 150         size_t ret = fwrite(ptr, size, nmemb, stream);
 151         if(!ferror(stream))
 152                 fflush(stream);
 153         return ret;
 154 }
 155 #else
 156 #define local__fwrite fwrite
 157 #endif
 158
 159 /****************************************************************************
 160  *
 161  * Level 0 implementation
 162  *
 163  ***************************************************************************/
 164
 165 static FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data);
 166 static void metadata_callback_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data);
 167 static void error_callback_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data);
 168
 169 typedef struct {
 170         FLAC__bool got_error;
 171         FLAC__StreamMetadata *object;
 172 } level0_client_data;
 173
 174 static FLAC__StreamMetadata *get_one_metadata_block_(const char *filename, FLAC__MetadataType type)
 175 {
 176         level0_client_data cd;
 177         FLAC__StreamDecoder *decoder;
 178
 179         FLAC__ASSERT(0 != filename);
 180
 181         cd.got_error = false;
 182         cd.object = 0;
 183
 184         decoder = FLAC__stream_decoder_new();
 185
 186         if(0 == decoder)
 187                 return 0;
 188
 189         FLAC__stream_decoder_set_md5_checking(decoder, false);
 190         FLAC__stream_decoder_set_metadata_ignore_all(decoder);
 191         FLAC__stream_decoder_set_metadata_respond(decoder, type);
 192
 193         if(FLAC__stream_decoder_init_file(decoder, filename, write_callback_, metadata_callback_, error_callback_, &cd) != FLAC__STREAM_DECODER_INIT_STATUS_OK || cd.got_error) {
 194                 (void)FLAC__stream_decoder_finish(decoder);
 195                 FLAC__stream_decoder_delete(decoder);
 196                 return 0;
 197         }
 198
 199         if(!FLAC__stream_decoder_process_until_end_of_metadata(decoder) || cd.got_error) {
 200                 (void)FLAC__stream_decoder_finish(decoder);
 201                 FLAC__stream_decoder_delete(decoder);
 202                 if(0 != cd.object)
 203                         FLAC__metadata_object_delete(cd.object);
 204                 return 0;
 205         }
 206
 207         (void)FLAC__stream_decoder_finish(decoder);
 208         FLAC__stream_decoder_delete(decoder);
 209
 210         return cd.object;
 211 }
 212
 213 FLAC_API FLAC__bool FLAC__metadata_get_streaminfo(const char *filename, FLAC__StreamMetadata *streaminfo)
 214 {
 215         FLAC__StreamMetadata *object;
 216
 217         FLAC__ASSERT(0 != filename);
 218         FLAC__ASSERT(0 != streaminfo);
 219
 220         object = get_one_metadata_block_(filename, FLAC__METADATA_TYPE_STREAMINFO);
 221
 222         if (object) {
 223                 /* can just copy the contents since STREAMINFO has no internal structure */
 224                 *streaminfo = *object;
 225                 FLAC__metadata_object_delete(object);
 226                 return true;
 227         }
 228         else {
 229                 return false;
 230         }
 231 }
 232
 233 FLAC_API FLAC__bool FLAC__metadata_get_tags(const char *filename, FLAC__StreamMetadata **tags)
 234 {
 235         FLAC__ASSERT(0 != filename);
 236         FLAC__ASSERT(0 != tags);
 237
 238         *tags = get_one_metadata_block_(filename, FLAC__METADATA_TYPE_VORBIS_COMMENT);
 239
 240         return 0 != *tags;
 241 }
 242
 243 FLAC_API FLAC__bool FLAC__metadata_get_cuesheet(const char *filename, FLAC__StreamMetadata **cuesheet)
 244 {
 245         FLAC__ASSERT(0 != filename);
 246         FLAC__ASSERT(0 != cuesheet);
 247
 248         *cuesheet = get_one_metadata_block_(filename, FLAC__METADATA_TYPE_CUESHEET);
 249
 250         return 0 != *cuesheet;
 251 }
 252
 253 FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
 254 {
 255         (void)decoder, (void)frame, (void)buffer, (void)client_data;
 256
 257         return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;
 258 }
 259
 260 void metadata_callback_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
 261 {
 262         level0_client_data *cd = (level0_client_data *)client_data;
 263         (void)decoder;
 264
 265         /*
 266          * we assume we only get here when the one metadata block we were
 267          * looking for was passed to us
 268          */
 269         if(!cd->got_error && 0 == cd->object) {
 270                 if(0 == (cd->object = FLAC__metadata_object_clone(metadata)))
 271                         cd->got_error = true;
 272         }
 273 }
 274
 275 void error_callback_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
 276 {
 277         level0_client_data *cd = (level0_client_data *)client_data;
 278         (void)decoder;
 279
 280         if(status != FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC)
 281                 cd->got_error = true;
 282 }
 283
 284 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)
 285 {
 286         FLAC__Metadata_SimpleIterator *it;
 287         FLAC__uint64 max_area_seen = 0;
 288         FLAC__uint64 max_depth_seen = 0;
 289
 290         FLAC__ASSERT(0 != filename);
 291         FLAC__ASSERT(0 != picture);
 292
 293         *picture = 0;
 294
 295         it = FLAC__metadata_simple_iterator_new();
 296         if(0 == it)
 297                 return false;
 298         if(!FLAC__metadata_simple_iterator_init(it, filename, /*read_only=*/true, /*preserve_file_stats=*/true)) {
 299                 FLAC__metadata_simple_iterator_delete(it);
 300                 return false;
 301         }
 302         do {
 303                 if(FLAC__metadata_simple_iterator_get_block_type(it) == FLAC__METADATA_TYPE_PICTURE) {
 304                         FLAC__StreamMetadata *obj = FLAC__metadata_simple_iterator_get_block(it);
 305                         FLAC__uint64 area = (FLAC__uint64)obj->data.picture.width * (FLAC__uint64)obj->data.picture.height;
 306                         /* check constraints */
 307                         if(
 308                                 (type == (FLAC__StreamMetadata_Picture_Type)(-1) || type == obj->data.picture.type) &&
 309                                 (mime_type == 0 || !strcmp(mime_type, obj->data.picture.mime_type)) &&
 310                                 (description == 0 || !strcmp((const char *)description, (const char *)obj->data.picture.description)) &&
 311                                 obj->data.picture.width <= max_width &&
 312                                 obj->data.picture.height <= max_height &&
 313                                 obj->data.picture.depth <= max_depth &&
 314                                 obj->data.picture.colors <= max_colors &&
 315                                 (area > max_area_seen || (area == max_area_seen && obj->data.picture.depth > max_depth_seen))
 316                         ) {
 317                                 if(*picture)
 318                                         FLAC__metadata_object_delete(*picture);
 319                                 *picture = obj;
 320                                 max_area_seen = area;
 321                                 max_depth_seen = obj->data.picture.depth;
 322                         }
 323                         else {
 324                                 FLAC__metadata_object_delete(obj);
 325                         }
 326                 }
 327         } while(FLAC__metadata_simple_iterator_next(it));
 328
 329         FLAC__metadata_simple_iterator_delete(it);
 330
 331         return (0 != *picture);
 332 }
 333
 334
 335 /****************************************************************************
 336  *
 337  * Level 1 implementation
 338  *
 339  ***************************************************************************/
 340
 341 #define SIMPLE_ITERATOR_MAX_PUSH_DEPTH (1+4)
 342 /* 1 for initial offset, +4 for our own personal use */
 343
 344 struct FLAC__Metadata_SimpleIterator {
 345         FILE *file;
 346         char *filename, *tempfile_path_prefix;
 347         struct stat stats;
 348         FLAC__bool has_stats;
 349         FLAC__bool is_writable;
 350         FLAC__Metadata_SimpleIteratorStatus status;
 351         off_t offset[SIMPLE_ITERATOR_MAX_PUSH_DEPTH];
 352         off_t first_offset; /* this is the offset to the STREAMINFO block */
 353         unsigned depth;
 354         /* this is the metadata block header of the current block we are pointing to: */
 355         FLAC__bool is_last;
 356         FLAC__MetadataType type;
 357         unsigned length;
 358 };
 359
 360 FLAC_API const char * const FLAC__Metadata_SimpleIteratorStatusString[] = {
 361         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK",
 362         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT",
 363         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE",
 364         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE",
 365         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE",
 366         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA",
 367         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR",
 368         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR",
 369         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR",
 370         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR",
 371         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR",
 372         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR",
 373         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR"
 374 };
 375
 376
 377 FLAC_API FLAC__Metadata_SimpleIterator *FLAC__metadata_simple_iterator_new(void)
 378 {
 379         FLAC__Metadata_SimpleIterator *iterator = (FLAC__Metadata_SimpleIterator*)calloc(1, sizeof(FLAC__Metadata_SimpleIterator));
 380
 381         if(0 != iterator) {
 382                 iterator->file = 0;
 383                 iterator->filename = 0;
 384                 iterator->tempfile_path_prefix = 0;
 385                 iterator->has_stats = false;
 386                 iterator->is_writable = false;
 387                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
 388                 iterator->first_offset = iterator->offset[0] = -1;
 389                 iterator->depth = 0;
 390         }
 391
 392         return iterator;
 393 }
 394
 395 static void simple_iterator_free_guts_(FLAC__Metadata_SimpleIterator *iterator)
 396 {
 397         FLAC__ASSERT(0 != iterator);
 398
 399         if(0 != iterator->file) {
 400                 fclose(iterator->file);
 401                 iterator->file = 0;
 402                 if(iterator->has_stats)
 403                         set_file_stats_(iterator->filename, &iterator->stats);
 404         }
 405         if(0 != iterator->filename) {
 406                 free(iterator->filename);
 407                 iterator->filename = 0;
 408         }
 409         if(0 != iterator->tempfile_path_prefix) {
 410                 free(iterator->tempfile_path_prefix);
 411                 iterator->tempfile_path_prefix = 0;
 412         }
 413 }
 414
 415 FLAC_API void FLAC__metadata_simple_iterator_delete(FLAC__Metadata_SimpleIterator *iterator)
 416 {
 417         FLAC__ASSERT(0 != iterator);
 418
 419         simple_iterator_free_guts_(iterator);
 420         free(iterator);
 421 }
 422
 423 FLAC_API FLAC__Metadata_SimpleIteratorStatus FLAC__metadata_simple_iterator_status(FLAC__Metadata_SimpleIterator *iterator)
 424 {
 425         FLAC__Metadata_SimpleIteratorStatus status;
 426
 427         FLAC__ASSERT(0 != iterator);
 428
 429         status = iterator->status;
 430         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
 431         return status;
 432 }
 433
 434 static FLAC__bool simple_iterator_prime_input_(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool read_only)
 435 {
 436         unsigned ret;
 437
 438         FLAC__ASSERT(0 != iterator);
 439
 440         if(read_only || 0 == (iterator->file = fopen(iterator->filename, "r+b"))) {
 441                 iterator->is_writable = false;
 442                 if(read_only || errno == EACCES) {
 443                         if(0 == (iterator->file = fopen(iterator->filename, "rb"))) {
 444                                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
 445                                 return false;
 446                         }
 447                 }
 448                 else {
 449                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
 450                         return false;
 451                 }
 452         }
 453         else {
 454                 iterator->is_writable = true;
 455         }
 456
 457         ret = seek_to_first_metadata_block_(iterator->file);
 458         switch(ret) {
 459                 case 0:
 460                         iterator->depth = 0;
 461                         iterator->first_offset = iterator->offset[iterator->depth] = ftello(iterator->file);
 462                         return read_metadata_block_header_(iterator);
 463                 case 1:
 464                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
 465                         return false;
 466                 case 2:
 467                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 468                         return false;
 469                 case 3:
 470                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE;
 471                         return false;
 472                 default:
 473                         FLAC__ASSERT(0);
 474                         return false;
 475         }
 476 }
 477
 478 #if 0
 479 @@@ If we decide to finish implementing this, put this comment back in metadata.h
 480 /*
 481  * The 'tempfile_path_prefix' allows you to specify a directory where
 482  * tempfiles should go.  Remember that if your metadata edits cause the
 483  * FLAC file to grow, the entire file will have to be rewritten.  If
 484  * 'tempfile_path_prefix' is NULL, the temp file will be written in the
 485  * same directory as the original FLAC file.  This makes replacing the
 486  * original with the tempfile fast but requires extra space in the same
 487  * partition for the tempfile.  If space is a problem, you can pass a
 488  * directory name belonging to a different partition in
 489  * 'tempfile_path_prefix'.  Note that you should use the forward slash
 490  * '/' as the directory separator.  A trailing slash is not needed; it
 491  * will be added automatically.
 492  */
 493 FLAC__bool FLAC__metadata_simple_iterator_init(FLAC__Metadata_SimpleIterator *iterator, const char *filename, FLAC__bool preserve_file_stats, const char *tempfile_path_prefix);
 494 #endif
 495
 496 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)
 497 {
 498         const char *tempfile_path_prefix = 0; /*@@@ search for comments near 'rename(...)' for what it will take to finish implementing this */
 499
 500         FLAC__ASSERT(0 != iterator);
 501         FLAC__ASSERT(0 != filename);
 502
 503         simple_iterator_free_guts_(iterator);
 504
 505         if(!read_only && preserve_file_stats)
 506                 iterator->has_stats = get_file_stats_(filename, &iterator->stats);
 507
 508         if(0 == (iterator->filename = strdup(filename))) {
 509                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 510                 return false;
 511         }
 512         if(0 != tempfile_path_prefix && 0 == (iterator->tempfile_path_prefix = strdup(tempfile_path_prefix))) {
 513                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 514                 return false;
 515         }
 516
 517         return simple_iterator_prime_input_(iterator, read_only);
 518 }
 519
 520 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_is_writable(const FLAC__Metadata_SimpleIterator *iterator)
 521 {
 522         FLAC__ASSERT(0 != iterator);
 523         FLAC__ASSERT(0 != iterator->file);
 524
 525         return iterator->is_writable;
 526 }
 527
 528 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_next(FLAC__Metadata_SimpleIterator *iterator)
 529 {
 530         FLAC__ASSERT(0 != iterator);
 531         FLAC__ASSERT(0 != iterator->file);
 532
 533         if(iterator->is_last)
 534                 return false;
 535
 536         if(0 != fseeko(iterator->file, iterator->length, SEEK_CUR)) {
 537                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 538                 return false;
 539         }
 540
 541         iterator->offset[iterator->depth] = ftello(iterator->file);
 542
 543         return read_metadata_block_header_(iterator);
 544 }
 545
 546 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_prev(FLAC__Metadata_SimpleIterator *iterator)
 547 {
 548         off_t this_offset;
 549
 550         FLAC__ASSERT(0 != iterator);
 551         FLAC__ASSERT(0 != iterator->file);
 552
 553         if(iterator->offset[iterator->depth] == iterator->first_offset)
 554                 return false;
 555
 556         if(0 != fseeko(iterator->file, iterator->first_offset, SEEK_SET)) {
 557                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 558                 return false;
 559         }
 560         this_offset = iterator->first_offset;
 561         if(!read_metadata_block_header_(iterator))
 562                 return false;
 563
 564         /* we ignore any error from ftello() and catch it in fseeko() */
 565         while(ftello(iterator->file) + (off_t)iterator->length < iterator->offset[iterator->depth]) {
 566                 if(0 != fseeko(iterator->file, iterator->length, SEEK_CUR)) {
 567                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 568                         return false;
 569                 }
 570                 this_offset = ftello(iterator->file);
 571                 if(!read_metadata_block_header_(iterator))
 572                         return false;
 573         }
 574
 575         iterator->offset[iterator->depth] = this_offset;
 576
 577         return true;
 578 }
 579
 580 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_is_last(const FLAC__Metadata_SimpleIterator *iterator)
 581 {
 582         FLAC__ASSERT(0 != iterator);
 583         FLAC__ASSERT(0 != iterator->file);
 584
 585         return iterator->is_last;
 586 }
 587
 588 FLAC_API off_t FLAC__metadata_simple_iterator_get_block_offset(const FLAC__Metadata_SimpleIterator *iterator)
 589 {
 590         FLAC__ASSERT(0 != iterator);
 591         FLAC__ASSERT(0 != iterator->file);
 592
 593         return iterator->offset[iterator->depth];
 594 }
 595
 596 FLAC_API FLAC__MetadataType FLAC__metadata_simple_iterator_get_block_type(const FLAC__Metadata_SimpleIterator *iterator)
 597 {
 598         FLAC__ASSERT(0 != iterator);
 599         FLAC__ASSERT(0 != iterator->file);
 600
 601         return iterator->type;
 602 }
 603
 604 FLAC_API unsigned FLAC__metadata_simple_iterator_get_block_length(const FLAC__Metadata_SimpleIterator *iterator)
 605 {
 606         FLAC__ASSERT(0 != iterator);
 607         FLAC__ASSERT(0 != iterator->file);
 608
 609         return iterator->length;
 610 }
 611
 612 FLAC_API FLAC__StreamMetadata *FLAC__metadata_simple_iterator_get_block(FLAC__Metadata_SimpleIterator *iterator)
 613 {
 614         FLAC__StreamMetadata *block = FLAC__metadata_object_new(iterator->type);
 615
 616         FLAC__ASSERT(0 != iterator);
 617         FLAC__ASSERT(0 != iterator->file);
 618
 619         if(0 != block) {
 620                 block->is_last = iterator->is_last;
 621                 block->length = iterator->length;
 622
 623                 if(!read_metadata_block_data_(iterator, block)) {
 624                         FLAC__metadata_object_delete(block);
 625                         return 0;
 626                 }
 627
 628                 /* back up to the beginning of the block data to stay consistent */
 629                 if(0 != fseeko(iterator->file, iterator->offset[iterator->depth] + FLAC__STREAM_METADATA_HEADER_LENGTH, SEEK_SET)) {
 630                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 631                         FLAC__metadata_object_delete(block);
 632                         return 0;
 633                 }
 634         }
 635         else
 636                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 637
 638         return block;
 639 }
 640
 641 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_set_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding)
 642 {
 643         FLAC__ASSERT_DECLARATION(off_t debug_target_offset = iterator->offset[iterator->depth];)
 644         FLAC__bool ret;
 645
 646         FLAC__ASSERT(0 != iterator);
 647         FLAC__ASSERT(0 != iterator->file);
 648         FLAC__ASSERT(0 != block);
 649
 650         if(!iterator->is_writable) {
 651                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE;
 652                 return false;
 653         }
 654
 655         if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO || block->type == FLAC__METADATA_TYPE_STREAMINFO) {
 656                 if(iterator->type != block->type) {
 657                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 658                         return false;
 659                 }
 660         }
 661
 662         block->is_last = iterator->is_last;
 663
 664         if(iterator->length == block->length)
 665                 return write_metadata_block_stationary_(iterator, block);
 666         else if(iterator->length > block->length) {
 667                 if(use_padding && iterator->length >= FLAC__STREAM_METADATA_HEADER_LENGTH + block->length) {
 668                         ret = write_metadata_block_stationary_with_padding_(iterator, block, iterator->length - FLAC__STREAM_METADATA_HEADER_LENGTH - block->length, block->is_last);
 669                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 670                         FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 671                         return ret;
 672                 }
 673                 else {
 674                         ret = rewrite_whole_file_(iterator, block, /*append=*/false);
 675                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 676                         FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 677                         return ret;
 678                 }
 679         }
 680         else /* iterator->length < block->length */ {
 681                 unsigned padding_leftover = 0;
 682                 FLAC__bool padding_is_last = false;
 683                 if(use_padding) {
 684                         /* first see if we can even use padding */
 685                         if(iterator->is_last) {
 686                                 use_padding = false;
 687                         }
 688                         else {
 689                                 const unsigned extra_padding_bytes_required = block->length - iterator->length;
 690                                 simple_iterator_push_(iterator);
 691                                 if(!FLAC__metadata_simple_iterator_next(iterator)) {
 692                                         (void)simple_iterator_pop_(iterator);
 693                                         return false;
 694                                 }
 695                                 if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
 696                                         use_padding = false;
 697                                 }
 698                                 else {
 699                                         if(FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length == extra_padding_bytes_required) {
 700                                                 padding_leftover = 0;
 701                                                 block->is_last = iterator->is_last;
 702                                         }
 703                                         else if(iterator->length < extra_padding_bytes_required)
 704                                                 use_padding = false;
 705                                         else {
 706                                                 padding_leftover = FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length - extra_padding_bytes_required;
 707                                                 padding_is_last = iterator->is_last;
 708                                                 block->is_last = false;
 709                                         }
 710                                 }
 711                                 if(!simple_iterator_pop_(iterator))
 712                                         return false;
 713                         }
 714                 }
 715                 if(use_padding) {
 716                         if(padding_leftover == 0) {
 717                                 ret = write_metadata_block_stationary_(iterator, block);
 718                                 FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 719                                 FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 720                                 return ret;
 721                         }
 722                         else {
 723                                 FLAC__ASSERT(padding_leftover >= FLAC__STREAM_METADATA_HEADER_LENGTH);
 724                                 ret = write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover - FLAC__STREAM_METADATA_HEADER_LENGTH, padding_is_last);
 725                                 FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 726                                 FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 727                                 return ret;
 728                         }
 729                 }
 730                 else {
 731                         ret = rewrite_whole_file_(iterator, block, /*append=*/false);
 732                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 733                         FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 734                         return ret;
 735                 }
 736         }
 737 }
 738
 739 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_insert_block_after(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding)
 740 {
 741         unsigned padding_leftover = 0;
 742         FLAC__bool padding_is_last = false;
 743
 744         FLAC__ASSERT_DECLARATION(off_t debug_target_offset = iterator->offset[iterator->depth] + FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length;)
 745         FLAC__bool ret;
 746
 747         FLAC__ASSERT(0 != iterator);
 748         FLAC__ASSERT(0 != iterator->file);
 749         FLAC__ASSERT(0 != block);
 750
 751         if(!iterator->is_writable)
 752                 return false;
 753
 754         if(block->type == FLAC__METADATA_TYPE_STREAMINFO) {
 755                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 756                 return false;
 757         }
 758
 759         block->is_last = iterator->is_last;
 760
 761         if(use_padding) {
 762                 /* first see if we can even use padding */
 763                 if(iterator->is_last) {
 764                         use_padding = false;
 765                 }
 766                 else {
 767                         simple_iterator_push_(iterator);
 768                         if(!FLAC__metadata_simple_iterator_next(iterator)) {
 769                                 (void)simple_iterator_pop_(iterator);
 770                                 return false;
 771                         }
 772                         if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
 773                                 use_padding = false;
 774                         }
 775                         else {
 776                                 if(iterator->length == block->length) {
 777                                         padding_leftover = 0;
 778                                         block->is_last = iterator->is_last;
 779                                 }
 780                                 else if(iterator->length < FLAC__STREAM_METADATA_HEADER_LENGTH + block->length)
 781                                         use_padding = false;
 782                                 else {
 783                                         padding_leftover = iterator->length - block->length;
 784                                         padding_is_last = iterator->is_last;
 785                                         block->is_last = false;
 786                                 }
 787                         }
 788                         if(!simple_iterator_pop_(iterator))
 789                                 return false;
 790                 }
 791         }
 792         if(use_padding) {
 793                 /* move to the next block, which is suitable padding */
 794                 if(!FLAC__metadata_simple_iterator_next(iterator))
 795                         return false;
 796                 if(padding_leftover == 0) {
 797                         ret = write_metadata_block_stationary_(iterator, block);
 798                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 799                         FLAC__ASSERT(ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 800                         return ret;
 801                 }
 802                 else {
 803                         FLAC__ASSERT(padding_leftover >= FLAC__STREAM_METADATA_HEADER_LENGTH);
 804                         ret = write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover - FLAC__STREAM_METADATA_HEADER_LENGTH, padding_is_last);
 805                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 806                         FLAC__ASSERT(ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 807                         return ret;
 808                 }
 809         }
 810         else {
 811                 ret = rewrite_whole_file_(iterator, block, /*append=*/true);
 812                 FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 813                 FLAC__ASSERT(ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 814                 return ret;
 815         }
 816 }
 817
 818 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_delete_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool use_padding)
 819 {
 820         FLAC__ASSERT_DECLARATION(off_t debug_target_offset = iterator->offset[iterator->depth];)
 821         FLAC__bool ret;
 822
 823         if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO) {
 824                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 825                 return false;
 826         }
 827
 828         if(use_padding) {
 829                 FLAC__StreamMetadata *padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING);
 830                 if(0 == padding) {
 831                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 832                         return false;
 833                 }
 834                 padding->length = iterator->length;
 835                 if(!FLAC__metadata_simple_iterator_set_block(iterator, padding, false)) {
 836                         FLAC__metadata_object_delete(padding);
 837                         return false;
 838                 }
 839                 FLAC__metadata_object_delete(padding);
 840                 if(!FLAC__metadata_simple_iterator_prev(iterator))
 841                         return false;
 842                 FLAC__ASSERT(iterator->offset[iterator->depth] + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length == debug_target_offset);
 843                 FLAC__ASSERT(ftello(iterator->file) + (off_t)iterator->length == debug_target_offset);
 844                 return true;
 845         }
 846         else {
 847                 ret = rewrite_whole_file_(iterator, 0, /*append=*/false);
 848                 FLAC__ASSERT(iterator->offset[iterator->depth] + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length == debug_target_offset);
 849                 FLAC__ASSERT(ftello(iterator->file) + (off_t)iterator->length == debug_target_offset);
 850                 return ret;
 851         }
 852 }
 853
 854
 855
 856 /****************************************************************************
 857  *
 858  * Level 2 implementation
 859  *
 860  ***************************************************************************/
 861
 862
 863 typedef struct FLAC__Metadata_Node {
 864         FLAC__StreamMetadata *data;
 865         struct FLAC__Metadata_Node *prev, *next;
 866 } FLAC__Metadata_Node;
 867
 868 struct FLAC__Metadata_Chain {
 869         char *filename; /* will be NULL if using callbacks */
 870         FLAC__bool is_ogg;
 871         FLAC__Metadata_Node *head;
 872         FLAC__Metadata_Node *tail;
 873         unsigned nodes;
 874         FLAC__Metadata_ChainStatus status;
 875         off_t first_offset, last_offset;
 876         /*
 877          * This is the length of the chain initially read from the FLAC file.
 878          * it is used to compare against the current length to decide whether
 879          * or not the whole file has to be rewritten.
 880          */
 881         off_t initial_length;
 882         /* @@@ hacky, these are currently only needed by ogg reader */
 883         FLAC__IOHandle handle;
 884         FLAC__IOCallback_Read read_cb;
 885 };
 886
 887 struct FLAC__Metadata_Iterator {
 888         FLAC__Metadata_Chain *chain;
 889         FLAC__Metadata_Node *current;
 890 };
 891
 892 FLAC_API const char * const FLAC__Metadata_ChainStatusString[] = {
 893         "FLAC__METADATA_CHAIN_STATUS_OK",
 894         "FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT",
 895         "FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE",
 896         "FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE",
 897         "FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE",
 898         "FLAC__METADATA_CHAIN_STATUS_BAD_METADATA",
 899         "FLAC__METADATA_CHAIN_STATUS_READ_ERROR",
 900         "FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR",
 901         "FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR",
 902         "FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR",
 903         "FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR",
 904         "FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR",
 905         "FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR",
 906         "FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS",
 907         "FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH",
 908         "FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL"
 909 };
 910
 911
 912 static FLAC__Metadata_Node *node_new_(void)
 913 {
 914         return (FLAC__Metadata_Node*)calloc(1, sizeof(FLAC__Metadata_Node));
 915 }
 916
 917 static void node_delete_(FLAC__Metadata_Node *node)
 918 {
 919         FLAC__ASSERT(0 != node);
 920         if(0 != node->data)
 921                 FLAC__metadata_object_delete(node->data);
 922         free(node);
 923 }
 924
 925 static void chain_init_(FLAC__Metadata_Chain *chain)
 926 {
 927         FLAC__ASSERT(0 != chain);
 928
 929         chain->filename = 0;
 930         chain->is_ogg = false;
 931         chain->head = chain->tail = 0;
 932         chain->nodes = 0;
 933         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
 934         chain->initial_length = 0;
 935         chain->read_cb = 0;
 936 }
 937
 938 static void chain_clear_(FLAC__Metadata_Chain *chain)
 939 {
 940         FLAC__Metadata_Node *node, *next;
 941
 942         FLAC__ASSERT(0 != chain);
 943
 944         for(node = chain->head; node; ) {
 945                 next = node->next;
 946                 node_delete_(node);
 947                 node = next;
 948         }
 949
 950         if(0 != chain->filename)
 951                 free(chain->filename);
 952
 953         chain_init_(chain);
 954 }
 955
 956 static void chain_append_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 957 {
 958         FLAC__ASSERT(0 != chain);
 959         FLAC__ASSERT(0 != node);
 960         FLAC__ASSERT(0 != node->data);
 961
 962         node->next = node->prev = 0;
 963         node->data->is_last = true;
 964         if(0 != chain->tail)
 965                 chain->tail->data->is_last = false;
 966
 967         if(0 == chain->head)
 968                 chain->head = node;
 969         else {
 970                 FLAC__ASSERT(0 != chain->tail);
 971                 chain->tail->next = node;
 972                 node->prev = chain->tail;
 973         }
 974         chain->tail = node;
 975         chain->nodes++;
 976 }
 977
 978 static void chain_remove_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 979 {
 980         FLAC__ASSERT(0 != chain);
 981         FLAC__ASSERT(0 != node);
 982
 983         if(node == chain->head)
 984                 chain->head = node->next;
 985         else
 986                 node->prev->next = node->next;
 987
 988         if(node == chain->tail)
 989                 chain->tail = node->prev;
 990         else
 991                 node->next->prev = node->prev;
 992
 993         if(0 != chain->tail)
 994                 chain->tail->data->is_last = true;
 995
 996         chain->nodes--;
 997 }
 998
 999 static void chain_delete_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
1000 {
1001         chain_remove_node_(chain, node);
1002         node_delete_(node);
1003 }
1004
1005 static off_t chain_calculate_length_(FLAC__Metadata_Chain *chain)
1006 {
1007         const FLAC__Metadata_Node *node;
1008         off_t length = 0;
1009         for(node = chain->head; node; node = node->next)
1010                 length += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1011         return length;
1012 }
1013
1014 static void iterator_insert_node_(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Node *node)
1015 {
1016         FLAC__ASSERT(0 != node);
1017         FLAC__ASSERT(0 != node->data);
1018         FLAC__ASSERT(0 != iterator);
1019         FLAC__ASSERT(0 != iterator->current);
1020         FLAC__ASSERT(0 != iterator->chain);
1021         FLAC__ASSERT(0 != iterator->chain->head);
1022         FLAC__ASSERT(0 != iterator->chain->tail);
1023
1024         node->data->is_last = false;
1025
1026         node->prev = iterator->current->prev;
1027         node->next = iterator->current;
1028
1029         if(0 == node->prev)
1030                 iterator->chain->head = node;
1031         else
1032                 node->prev->next = node;
1033
1034         iterator->current->prev = node;
1035
1036         iterator->chain->nodes++;
1037 }
1038
1039 static void iterator_insert_node_after_(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Node *node)
1040 {
1041         FLAC__ASSERT(0 != node);
1042         FLAC__ASSERT(0 != node->data);
1043         FLAC__ASSERT(0 != iterator);
1044         FLAC__ASSERT(0 != iterator->current);
1045         FLAC__ASSERT(0 != iterator->chain);
1046         FLAC__ASSERT(0 != iterator->chain->head);
1047         FLAC__ASSERT(0 != iterator->chain->tail);
1048
1049         iterator->current->data->is_last = false;
1050
1051         node->prev = iterator->current;
1052         node->next = iterator->current->next;
1053
1054         if(0 == node->next)
1055                 iterator->chain->tail = node;
1056         else
1057                 node->next->prev = node;
1058
1059         node->prev->next = node;
1060
1061         iterator->chain->tail->data->is_last = true;
1062
1063         iterator->chain->nodes++;
1064 }
1065
1066 /* return true iff node and node->next are both padding */
1067 static FLAC__bool chain_merge_adjacent_padding_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
1068 {
1069         if(node->data->type == FLAC__METADATA_TYPE_PADDING && 0 != node->next && node->next->data->type == FLAC__METADATA_TYPE_PADDING) {
1070                 const unsigned growth = FLAC__STREAM_METADATA_HEADER_LENGTH + node->next->data->length;
1071                 node->data->length += growth;
1072
1073                 chain_delete_node_(chain, node->next);
1074                 return true;
1075         }
1076         else
1077                 return false;
1078 }
1079
1080 /* Returns the new length of the chain, or 0 if there was an error. */
1081 /* WATCHOUT: This can get called multiple times before a write, so
1082  * it should still work when this happens.
1083  */
1084 /* WATCHOUT: Make sure to also update the logic in
1085  * FLAC__metadata_chain_check_if_tempfile_needed() if the logic here changes.
1086  */
1087 static off_t chain_prepare_for_write_(FLAC__Metadata_Chain *chain, FLAC__bool use_padding)
1088 {
1089         off_t current_length = chain_calculate_length_(chain);
1090
1091         if(use_padding) {
1092                 /* if the metadata shrank and the last block is padding, we just extend the last padding block */
1093                 if(current_length < chain->initial_length && chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1094                         const off_t delta = chain->initial_length - current_length;
1095                         chain->tail->data->length += delta;
1096                         current_length += delta;
1097                         FLAC__ASSERT(current_length == chain->initial_length);
1098                 }
1099                 /* if the metadata shrank more than 4 bytes then there's room to add another padding block */
1100                 else if(current_length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH <= chain->initial_length) {
1101                         FLAC__StreamMetadata *padding;
1102                         FLAC__Metadata_Node *node;
1103                         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING))) {
1104                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1105                                 return 0;
1106                         }
1107                         padding->length = chain->initial_length - (FLAC__STREAM_METADATA_HEADER_LENGTH + current_length);
1108                         if(0 == (node = node_new_())) {
1109                                 FLAC__metadata_object_delete(padding);
1110                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1111                                 return 0;
1112                         }
1113                         node->data = padding;
1114                         chain_append_node_(chain, node);
1115                         current_length = chain_calculate_length_(chain);
1116                         FLAC__ASSERT(current_length == chain->initial_length);
1117                 }
1118                 /* 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 */
1119                 else if(current_length > chain->initial_length) {
1120                         const off_t delta = current_length - chain->initial_length;
1121                         if(chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1122                                 /* if the delta is exactly the size of the last padding block, remove the padding block */
1123                                 if((off_t)chain->tail->data->length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH == delta) {
1124                                         chain_delete_node_(chain, chain->tail);
1125                                         current_length = chain_calculate_length_(chain);
1126                                         FLAC__ASSERT(current_length == chain->initial_length);
1127                                 }
1128                                 /* if there is at least 'delta' bytes of padding, trim the padding down */
1129                                 else if((off_t)chain->tail->data->length >= delta) {
1130                                         chain->tail->data->length -= delta;
1131                                         current_length -= delta;
1132                                         FLAC__ASSERT(current_length == chain->initial_length);
1133                                 }
1134                         }
1135                 }
1136         }
1137
1138         return current_length;
1139 }
1140
1141 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)
1142 {
1143         FLAC__Metadata_Node *node;
1144
1145         FLAC__ASSERT(0 != chain);
1146
1147         /* we assume we're already at the beginning of the file */
1148
1149         switch(seek_to_first_metadata_block_cb_(handle, read_cb, seek_cb)) {
1150                 case 0:
1151                         break;
1152                 case 1:
1153                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1154                         return false;
1155                 case 2:
1156                         chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1157                         return false;
1158                 case 3:
1159                         chain->status = FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE;
1160                         return false;
1161                 default:
1162                         FLAC__ASSERT(0);
1163                         return false;
1164         }
1165
1166         {
1167                 FLAC__int64 pos = tell_cb(handle);
1168                 if(pos < 0) {
1169                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1170                         return false;
1171                 }
1172                 chain->first_offset = (off_t)pos;
1173         }
1174
1175         {
1176                 FLAC__bool is_last;
1177                 FLAC__MetadataType type;
1178                 unsigned length;
1179
1180                 do {
1181                         node = node_new_();
1182                         if(0 == node) {
1183                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1184                                 return false;
1185                         }
1186
1187                         if(!read_metadata_block_header_cb_(handle, read_cb, &is_last, &type, &length)) {
1188                                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1189                                 return false;
1190                         }
1191
1192                         node->data = FLAC__metadata_object_new(type);
1193                         if(0 == node->data) {
1194                                 node_delete_(node);
1195                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1196                                 return false;
1197                         }
1198
1199                         node->data->is_last = is_last;
1200                         node->data->length = length;
1201
1202                         chain->status = get_equivalent_status_(read_metadata_block_data_cb_(handle, read_cb, seek_cb, node->data));
1203                         if(chain->status != FLAC__METADATA_CHAIN_STATUS_OK) {
1204                                 node_delete_(node);
1205                                 return false;
1206                         }
1207                         chain_append_node_(chain, node);
1208                 } while(!is_last);
1209         }
1210
1211         {
1212                 FLAC__int64 pos = tell_cb(handle);
1213                 if(pos < 0) {
1214                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1215                         return false;
1216                 }
1217                 chain->last_offset = (off_t)pos;
1218         }
1219
1220         chain->initial_length = chain_calculate_length_(chain);
1221
1222         return true;
1223 }
1224
1225 static FLAC__StreamDecoderReadStatus chain_read_ogg_read_cb_(const FLAC__StreamDecoder *decoder, FLAC__byte buffer[], size_t *bytes, void *client_data)
1226 {
1227         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1228         (void)decoder;
1229         if(*bytes > 0 && chain->status == FLAC__METADATA_CHAIN_STATUS_OK) {
1230                 *bytes = chain->read_cb(buffer, sizeof(FLAC__byte), *bytes, chain->handle);
1231                 if(*bytes == 0)
1232                         return FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM;
1233                 else
1234                         return FLAC__STREAM_DECODER_READ_STATUS_CONTINUE;
1235         }
1236         else
1237                 return FLAC__STREAM_DECODER_READ_STATUS_ABORT;
1238 }
1239
1240 static FLAC__StreamDecoderWriteStatus chain_read_ogg_write_cb_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
1241 {
1242         (void)decoder, (void)frame, (void)buffer, (void)client_data;
1243         return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
1244 }
1245
1246 static void chain_read_ogg_metadata_cb_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
1247 {
1248         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1249         FLAC__Metadata_Node *node;
1250
1251         (void)decoder;
1252
1253         node = node_new_();
1254         if(0 == node) {
1255                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1256                 return;
1257         }
1258
1259         node->data = FLAC__metadata_object_clone(metadata);
1260         if(0 == node->data) {
1261                 node_delete_(node);
1262                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1263                 return;
1264         }
1265
1266         chain_append_node_(chain, node);
1267 }
1268
1269 static void chain_read_ogg_error_cb_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
1270 {
1271         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1272         (void)decoder, (void)status;
1273         chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1274 }
1275
1276 static FLAC__bool chain_read_ogg_cb_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb)
1277 {
1278         FLAC__StreamDecoder *decoder;
1279
1280         FLAC__ASSERT(0 != chain);
1281
1282         /* we assume we're already at the beginning of the file */
1283
1284         chain->handle = handle;
1285         chain->read_cb = read_cb;
1286         if(0 == (decoder = FLAC__stream_decoder_new())) {
1287                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1288                 return false;
1289         }
1290         FLAC__stream_decoder_set_metadata_respond_all(decoder);
1291         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) {
1292                 FLAC__stream_decoder_delete(decoder);
1293                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1294                 return false;
1295         }
1296
1297         chain->first_offset = 0; /*@@@ wrong; will need to be set correctly to implement metadata writing for Ogg FLAC */
1298
1299         if(!FLAC__stream_decoder_process_until_end_of_metadata(decoder))
1300                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1301         if(chain->status != FLAC__METADATA_CHAIN_STATUS_OK) {
1302                 FLAC__stream_decoder_delete(decoder);
1303                 return false;
1304         }
1305
1306         FLAC__stream_decoder_delete(decoder);
1307
1308         chain->last_offset = 0; /*@@@ wrong; will need to be set correctly to implement metadata writing for Ogg FLAC */
1309
1310         chain->initial_length = chain_calculate_length_(chain);
1311
1312         return true;
1313 }
1314
1315 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)
1316 {
1317         FLAC__Metadata_Node *node;
1318
1319         FLAC__ASSERT(0 != chain);
1320         FLAC__ASSERT(0 != chain->head);
1321
1322         if(0 != seek_cb(handle, chain->first_offset, SEEK_SET)) {
1323                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1324                 return false;
1325         }
1326
1327         for(node = chain->head; node; node = node->next) {
1328                 if(!write_metadata_block_header_cb_(handle, write_cb, node->data)) {
1329                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1330                         return false;
1331                 }
1332                 if(!write_metadata_block_data_cb_(handle, write_cb, node->data)) {
1333                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1334                         return false;
1335                 }
1336         }
1337
1338         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1339
1340         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
1341         return true;
1342 }
1343
1344 static FLAC__bool chain_rewrite_metadata_in_place_(FLAC__Metadata_Chain *chain)
1345 {
1346         FILE *file;
1347         FLAC__bool ret;
1348
1349         FLAC__ASSERT(0 != chain->filename);
1350
1351         if(0 == (file = fopen(chain->filename, "r+b"))) {
1352                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1353                 return false;
1354         }
1355
1356         /* chain_rewrite_metadata_in_place_cb_() sets chain->status for us */
1357         ret = chain_rewrite_metadata_in_place_cb_(chain, (FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, fseek_wrapper_);
1358
1359         fclose(file);
1360
1361         return ret;
1362 }
1363
1364 static FLAC__bool chain_rewrite_file_(FLAC__Metadata_Chain *chain, const char *tempfile_path_prefix)
1365 {
1366         FILE *f, *tempfile;
1367         char *tempfilename;
1368         FLAC__Metadata_SimpleIteratorStatus status;
1369         const FLAC__Metadata_Node *node;
1370
1371         FLAC__ASSERT(0 != chain);
1372         FLAC__ASSERT(0 != chain->filename);
1373         FLAC__ASSERT(0 != chain->head);
1374
1375         /* copy the file prefix (data up to first metadata block */
1376         if(0 == (f = fopen(chain->filename, "rb"))) {
1377                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1378                 return false;
1379         }
1380         if(!open_tempfile_(chain->filename, tempfile_path_prefix, &tempfile, &tempfilename, &status)) {
1381                 chain->status = get_equivalent_status_(status);
1382                 cleanup_tempfile_(&tempfile, &tempfilename);
1383                 return false;
1384         }
1385         if(!copy_n_bytes_from_file_(f, tempfile, chain->first_offset, &status)) {
1386                 chain->status = get_equivalent_status_(status);
1387                 cleanup_tempfile_(&tempfile, &tempfilename);
1388                 return false;
1389         }
1390
1391         /* write the metadata */
1392         for(node = chain->head; node; node = node->next) {
1393                 if(!write_metadata_block_header_(tempfile, &status, node->data)) {
1394                         chain->status = get_equivalent_status_(status);
1395                         return false;
1396                 }
1397                 if(!write_metadata_block_data_(tempfile, &status, node->data)) {
1398                         chain->status = get_equivalent_status_(status);
1399                         return false;
1400                 }
1401         }
1402         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1403
1404         /* copy the file postfix (everything after the metadata) */
1405         if(0 != fseeko(f, chain->last_offset, SEEK_SET)) {
1406                 cleanup_tempfile_(&tempfile, &tempfilename);
1407                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1408                 return false;
1409         }
1410         if(!copy_remaining_bytes_from_file_(f, tempfile, &status)) {
1411                 cleanup_tempfile_(&tempfile, &tempfilename);
1412                 chain->status = get_equivalent_status_(status);
1413                 return false;
1414         }
1415
1416         /* move the tempfile on top of the original */
1417         (void)fclose(f);
1418         if(!transport_tempfile_(chain->filename, &tempfile, &tempfilename, &status))
1419                 return false;
1420
1421         return true;
1422 }
1423
1424 /* assumes 'handle' is already at beginning of file */
1425 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)
1426 {
1427         FLAC__Metadata_SimpleIteratorStatus status;
1428         const FLAC__Metadata_Node *node;
1429
1430         FLAC__ASSERT(0 != chain);
1431         FLAC__ASSERT(0 == chain->filename);
1432         FLAC__ASSERT(0 != chain->head);
1433
1434         /* copy the file prefix (data up to first metadata block */
1435         if(!copy_n_bytes_from_file_cb_(handle, read_cb, temp_handle, temp_write_cb, chain->first_offset, &status)) {
1436                 chain->status = get_equivalent_status_(status);
1437                 return false;
1438         }
1439
1440         /* write the metadata */
1441         for(node = chain->head; node; node = node->next) {
1442                 if(!write_metadata_block_header_cb_(temp_handle, temp_write_cb, node->data)) {
1443                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1444                         return false;
1445                 }
1446                 if(!write_metadata_block_data_cb_(temp_handle, temp_write_cb, node->data)) {
1447                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1448                         return false;
1449                 }
1450         }
1451         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1452
1453         /* copy the file postfix (everything after the metadata) */
1454         if(0 != seek_cb(handle, chain->last_offset, SEEK_SET)) {
1455                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1456                 return false;
1457         }
1458         if(!copy_remaining_bytes_from_file_cb_(handle, read_cb, eof_cb, temp_handle, temp_write_cb, &status)) {
1459                 chain->status = get_equivalent_status_(status);
1460                 return false;
1461         }
1462
1463         return true;
1464 }
1465
1466 FLAC_API FLAC__Metadata_Chain *FLAC__metadata_chain_new(void)
1467 {
1468         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)calloc(1, sizeof(FLAC__Metadata_Chain));
1469
1470         if(0 != chain)
1471                 chain_init_(chain);
1472
1473         return chain;
1474 }
1475
1476 FLAC_API void FLAC__metadata_chain_delete(FLAC__Metadata_Chain *chain)
1477 {
1478         FLAC__ASSERT(0 != chain);
1479
1480         chain_clear_(chain);
1481
1482         free(chain);
1483 }
1484
1485 FLAC_API FLAC__Metadata_ChainStatus FLAC__metadata_chain_status(FLAC__Metadata_Chain *chain)
1486 {
1487         FLAC__Metadata_ChainStatus status;
1488
1489         FLAC__ASSERT(0 != chain);
1490
1491         status = chain->status;
1492         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
1493         return status;
1494 }
1495
1496 static FLAC__bool chain_read_(FLAC__Metadata_Chain *chain, const char *filename, FLAC__bool is_ogg)
1497 {
1498         FILE *file;
1499         FLAC__bool ret;
1500
1501         FLAC__ASSERT(0 != chain);
1502         FLAC__ASSERT(0 != filename);
1503
1504         chain_clear_(chain);
1505
1506         if(0 == (chain->filename = strdup(filename))) {
1507                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1508                 return false;
1509         }
1510
1511         chain->is_ogg = is_ogg;
1512
1513         if(0 == (file = fopen(filename, "rb"))) {
1514                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1515                 return false;
1516         }
1517
1518         /* the function also sets chain->status for us */
1519         ret = is_ogg?
1520                 chain_read_ogg_cb_(chain, file, (FLAC__IOCallback_Read)fread) :
1521                 chain_read_cb_(chain, file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, ftell_wrapper_)
1522         ;
1523
1524         fclose(file);
1525
1526         return ret;
1527 }
1528
1529 FLAC_API FLAC__bool FLAC__metadata_chain_read(FLAC__Metadata_Chain *chain, const char *filename)
1530 {
1531         return chain_read_(chain, filename, /*is_ogg=*/false);
1532 }
1533
1534 FLAC_API FLAC__bool FLAC__metadata_chain_read_ogg(FLAC__Metadata_Chain *chain, const char *filename)
1535 {
1536         return chain_read_(chain, filename, /*is_ogg=*/true);
1537 }
1538
1539 static FLAC__bool chain_read_with_callbacks_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks, FLAC__bool is_ogg)
1540 {
1541         FLAC__bool ret;
1542
1543         FLAC__ASSERT(0 != chain);
1544
1545         chain_clear_(chain);
1546
1547         if (0 == callbacks.read || 0 == callbacks.seek || 0 == callbacks.tell) {
1548                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1549                 return false;
1550         }
1551
1552         chain->is_ogg = is_ogg;
1553
1554         /* rewind */
1555         if(0 != callbacks.seek(handle, 0, SEEK_SET)) {
1556                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1557                 return false;
1558         }
1559
1560         /* the function also sets chain->status for us */
1561         ret = is_ogg?
1562                 chain_read_ogg_cb_(chain, handle, callbacks.read) :
1563                 chain_read_cb_(chain, handle, callbacks.read, callbacks.seek, callbacks.tell)
1564         ;
1565
1566         return ret;
1567 }
1568
1569 FLAC_API FLAC__bool FLAC__metadata_chain_read_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1570 {
1571         return chain_read_with_callbacks_(chain, handle, callbacks, /*is_ogg=*/false);
1572 }
1573
1574 FLAC_API FLAC__bool FLAC__metadata_chain_read_ogg_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1575 {
1576         return chain_read_with_callbacks_(chain, handle, callbacks, /*is_ogg=*/true);
1577 }
1578
1579 FLAC_API FLAC__bool FLAC__metadata_chain_check_if_tempfile_needed(FLAC__Metadata_Chain *chain, FLAC__bool use_padding)
1580 {
1581         /* This does all the same checks that are in chain_prepare_for_write_()
1582          * but doesn't actually alter the chain.  Make sure to update the logic
1583          * here if chain_prepare_for_write_() changes.
1584          */
1585         const off_t current_length = chain_calculate_length_(chain);
1586
1587         FLAC__ASSERT(0 != chain);
1588
1589         if(use_padding) {
1590                 /* if the metadata shrank and the last block is padding, we just extend the last padding block */
1591                 if(current_length < chain->initial_length && chain->tail->data->type == FLAC__METADATA_TYPE_PADDING)
1592                         return false;
1593                 /* if the metadata shrank more than 4 bytes then there's room to add another padding block */
1594                 else if(current_length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH <= chain->initial_length)
1595                         return false;
1596                 /* 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 */
1597                 else if(current_length > chain->initial_length) {
1598                         const off_t delta = current_length - chain->initial_length;
1599                         if(chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1600                                 /* if the delta is exactly the size of the last padding block, remove the padding block */
1601                                 if((off_t)chain->tail->data->length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH == delta)
1602                                         return false;
1603                                 /* if there is at least 'delta' bytes of padding, trim the padding down */
1604                                 else if((off_t)chain->tail->data->length >= delta)
1605                                         return false;
1606                         }
1607                 }
1608         }
1609
1610         return (current_length != chain->initial_length);
1611 }
1612
1613 FLAC_API FLAC__bool FLAC__metadata_chain_write(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__bool preserve_file_stats)
1614 {
1615         struct stat stats;
1616         const char *tempfile_path_prefix = 0;
1617         off_t current_length;
1618
1619         FLAC__ASSERT(0 != chain);
1620
1621         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1622                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1623                 return false;
1624         }
1625
1626         if (0 == chain->filename) {
1627                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1628                 return false;
1629         }
1630
1631         current_length = chain_prepare_for_write_(chain, use_padding);
1632
1633         /* a return value of 0 means there was an error; chain->status is already set */
1634         if (0 == current_length)
1635                 return false;
1636
1637         if(preserve_file_stats)
1638                 get_file_stats_(chain->filename, &stats);
1639
1640         if(current_length == chain->initial_length) {
1641                 if(!chain_rewrite_metadata_in_place_(chain))
1642                         return false;
1643         }
1644         else {
1645                 if(!chain_rewrite_file_(chain, tempfile_path_prefix))
1646                         return false;
1647
1648                 /* recompute lengths and offsets */
1649                 {
1650                         const FLAC__Metadata_Node *node;
1651                         chain->initial_length = current_length;
1652                         chain->last_offset = chain->first_offset;
1653                         for(node = chain->head; node; node = node->next)
1654                                 chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1655                 }
1656         }
1657
1658         if(preserve_file_stats)
1659                 set_file_stats_(chain->filename, &stats);
1660
1661         return true;
1662 }
1663
1664 FLAC_API FLAC__bool FLAC__metadata_chain_write_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1665 {
1666         off_t current_length;
1667
1668         FLAC__ASSERT(0 != chain);
1669
1670         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1671                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1672                 return false;
1673         }
1674
1675         if (0 != chain->filename) {
1676                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1677                 return false;
1678         }
1679
1680         if (0 == callbacks.write || 0 == callbacks.seek) {
1681                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1682                 return false;
1683         }
1684
1685         if (FLAC__metadata_chain_check_if_tempfile_needed(chain, use_padding)) {
1686                 chain->status = FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL;
1687                 return false;
1688         }
1689
1690         current_length = chain_prepare_for_write_(chain, use_padding);
1691
1692         /* a return value of 0 means there was an error; chain->status is already set */
1693         if (0 == current_length)
1694                 return false;
1695
1696         FLAC__ASSERT(current_length == chain->initial_length);
1697
1698         return chain_rewrite_metadata_in_place_cb_(chain, handle, callbacks.write, callbacks.seek);
1699 }
1700
1701 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)
1702 {
1703         off_t current_length;
1704
1705         FLAC__ASSERT(0 != chain);
1706
1707         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1708                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1709                 return false;
1710         }
1711
1712         if (0 != chain->filename) {
1713                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1714                 return false;
1715         }
1716
1717         if (0 == callbacks.read || 0 == callbacks.seek || 0 == callbacks.eof) {
1718                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1719                 return false;
1720         }
1721         if (0 == temp_callbacks.write) {
1722                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1723                 return false;
1724         }
1725
1726         if (!FLAC__metadata_chain_check_if_tempfile_needed(chain, use_padding)) {
1727                 chain->status = FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL;
1728                 return false;
1729         }
1730
1731         current_length = chain_prepare_for_write_(chain, use_padding);
1732
1733         /* a return value of 0 means there was an error; chain->status is already set */
1734         if (0 == current_length)
1735                 return false;
1736
1737         FLAC__ASSERT(current_length != chain->initial_length);
1738
1739         /* rewind */
1740         if(0 != callbacks.seek(handle, 0, SEEK_SET)) {
1741                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1742                 return false;
1743         }
1744
1745         if(!chain_rewrite_file_cb_(chain, handle, callbacks.read, callbacks.seek, callbacks.eof, temp_handle, temp_callbacks.write))
1746                 return false;
1747
1748         /* recompute lengths and offsets */
1749         {
1750                 const FLAC__Metadata_Node *node;
1751                 chain->initial_length = current_length;
1752                 chain->last_offset = chain->first_offset;
1753                 for(node = chain->head; node; node = node->next)
1754                         chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1755         }
1756
1757         return true;
1758 }
1759
1760 FLAC_API void FLAC__metadata_chain_merge_padding(FLAC__Metadata_Chain *chain)
1761 {
1762         FLAC__Metadata_Node *node;
1763
1764         FLAC__ASSERT(0 != chain);
1765
1766         for(node = chain->head; node; ) {
1767                 if(!chain_merge_adjacent_padding_(chain, node))
1768                         node = node->next;
1769         }
1770 }
1771
1772 FLAC_API void FLAC__metadata_chain_sort_padding(FLAC__Metadata_Chain *chain)
1773 {
1774         FLAC__Metadata_Node *node, *save;
1775         unsigned i;
1776
1777         FLAC__ASSERT(0 != chain);
1778
1779         /*
1780          * Don't try and be too smart... this simple algo is good enough for
1781          * the small number of nodes that we deal with.
1782          */
1783         for(i = 0, node = chain->head; i < chain->nodes; i++) {
1784                 if(node->data->type == FLAC__METADATA_TYPE_PADDING) {
1785                         save = node->next;
1786                         chain_remove_node_(chain, node);
1787                         chain_append_node_(chain, node);
1788                         node = save;
1789                 }
1790                 else {
1791                         node = node->next;
1792                 }
1793         }
1794
1795         FLAC__metadata_chain_merge_padding(chain);
1796 }
1797
1798
1799 FLAC_API FLAC__Metadata_Iterator *FLAC__metadata_iterator_new(void)
1800 {
1801         FLAC__Metadata_Iterator *iterator = (FLAC__Metadata_Iterator*)calloc(1, sizeof(FLAC__Metadata_Iterator));
1802
1803         /* calloc() implies:
1804                 iterator->current = 0;
1805                 iterator->chain = 0;
1806         */
1807
1808         return iterator;
1809 }
1810
1811 FLAC_API void FLAC__metadata_iterator_delete(FLAC__Metadata_Iterator *iterator)
1812 {
1813         FLAC__ASSERT(0 != iterator);
1814
1815         free(iterator);
1816 }
1817
1818 FLAC_API void FLAC__metadata_iterator_init(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Chain *chain)
1819 {
1820         FLAC__ASSERT(0 != iterator);
1821         FLAC__ASSERT(0 != chain);
1822         FLAC__ASSERT(0 != chain->head);
1823
1824         iterator->chain = chain;
1825         iterator->current = chain->head;
1826 }
1827
1828 FLAC_API FLAC__bool FLAC__metadata_iterator_next(FLAC__Metadata_Iterator *iterator)
1829 {
1830         FLAC__ASSERT(0 != iterator);
1831
1832         if(0 == iterator->current || 0 == iterator->current->next)
1833                 return false;
1834
1835         iterator->current = iterator->current->next;
1836         return true;
1837 }
1838
1839 FLAC_API FLAC__bool FLAC__metadata_iterator_prev(FLAC__Metadata_Iterator *iterator)
1840 {
1841         FLAC__ASSERT(0 != iterator);
1842
1843         if(0 == iterator->current || 0 == iterator->current->prev)
1844                 return false;
1845
1846         iterator->current = iterator->current->prev;
1847         return true;
1848 }
1849
1850 FLAC_API FLAC__MetadataType FLAC__metadata_iterator_get_block_type(const FLAC__Metadata_Iterator *iterator)
1851 {
1852         FLAC__ASSERT(0 != iterator);
1853         FLAC__ASSERT(0 != iterator->current);
1854         FLAC__ASSERT(0 != iterator->current->data);
1855
1856         return iterator->current->data->type;
1857 }
1858
1859 FLAC_API FLAC__StreamMetadata *FLAC__metadata_iterator_get_block(FLAC__Metadata_Iterator *iterator)
1860 {
1861         FLAC__ASSERT(0 != iterator);
1862         FLAC__ASSERT(0 != iterator->current);
1863
1864         return iterator->current->data;
1865 }
1866
1867 FLAC_API FLAC__bool FLAC__metadata_iterator_set_block(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1868 {
1869         FLAC__ASSERT(0 != iterator);
1870         FLAC__ASSERT(0 != block);
1871         return FLAC__metadata_iterator_delete_block(iterator, false) && FLAC__metadata_iterator_insert_block_after(iterator, block);
1872 }
1873
1874 FLAC_API FLAC__bool FLAC__metadata_iterator_delete_block(FLAC__Metadata_Iterator *iterator, FLAC__bool replace_with_padding)
1875 {
1876         FLAC__Metadata_Node *save;
1877
1878         FLAC__ASSERT(0 != iterator);
1879         FLAC__ASSERT(0 != iterator->current);
1880
1881         if(0 == iterator->current->prev) {
1882                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1883                 return false;
1884         }
1885
1886         save = iterator->current->prev;
1887
1888         if(replace_with_padding) {
1889                 FLAC__metadata_object_delete_data(iterator->current->data);
1890                 iterator->current->data->type = FLAC__METADATA_TYPE_PADDING;
1891         }
1892         else {
1893                 chain_delete_node_(iterator->chain, iterator->current);
1894         }
1895
1896         iterator->current = save;
1897         return true;
1898 }
1899
1900 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_before(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1901 {
1902         FLAC__Metadata_Node *node;
1903
1904         FLAC__ASSERT(0 != iterator);
1905         FLAC__ASSERT(0 != iterator->current);
1906         FLAC__ASSERT(0 != block);
1907
1908         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1909                 return false;
1910
1911         if(0 == iterator->current->prev) {
1912                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1913                 return false;
1914         }
1915
1916         if(0 == (node = node_new_()))
1917                 return false;
1918
1919         node->data = block;
1920         iterator_insert_node_(iterator, node);
1921         iterator->current = node;
1922         return true;
1923 }
1924
1925 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_after(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1926 {
1927         FLAC__Metadata_Node *node;
1928
1929         FLAC__ASSERT(0 != iterator);
1930         FLAC__ASSERT(0 != iterator->current);
1931         FLAC__ASSERT(0 != block);
1932
1933         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1934                 return false;
1935
1936         if(0 == (node = node_new_()))
1937                 return false;
1938
1939         node->data = block;
1940         iterator_insert_node_after_(iterator, node);
1941         iterator->current = node;
1942         return true;
1943 }
1944
1945
1946 /****************************************************************************
1947  *
1948  * Local function definitions
1949  *
1950  ***************************************************************************/
1951
1952 void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
1953 {
1954         unsigned i;
1955
1956         b += bytes;
1957
1958         for(i = 0; i < bytes; i++) {
1959                 *(--b) = (FLAC__byte)(val & 0xff);
1960                 val >>= 8;
1961         }
1962 }
1963
1964 void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
1965 {
1966         unsigned i;
1967
1968         for(i = 0; i < bytes; i++) {
1969                 *(b++) = (FLAC__byte)(val & 0xff);
1970                 val >>= 8;
1971         }
1972 }
1973
1974 void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes)
1975 {
1976         unsigned i;
1977
1978         b += bytes;
1979
1980         for(i = 0; i < bytes; i++) {
1981                 *(--b) = (FLAC__byte)(val & 0xff);
1982                 val >>= 8;
1983         }
1984 }
1985
1986 FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes)
1987 {
1988         FLAC__uint32 ret = 0;
1989         unsigned i;
1990
1991         for(i = 0; i < bytes; i++)
1992                 ret = (ret << 8) | (FLAC__uint32)(*b++);
1993
1994         return ret;
1995 }
1996
1997 FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes)
1998 {
1999         FLAC__uint32 ret = 0;
2000         unsigned i;
2001
2002         b += bytes;
2003
2004         for(i = 0; i < bytes; i++)
2005                 ret = (ret << 8) | (FLAC__uint32)(*--b);
2006
2007         return ret;
2008 }
2009
2010 FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes)
2011 {
2012         FLAC__uint64 ret = 0;
2013         unsigned i;
2014
2015         for(i = 0; i < bytes; i++)
2016                 ret = (ret << 8) | (FLAC__uint64)(*b++);
2017
2018         return ret;
2019 }
2020
2021 FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator)
2022 {
2023         FLAC__ASSERT(0 != iterator);
2024         FLAC__ASSERT(0 != iterator->file);
2025
2026         if(!read_metadata_block_header_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, &iterator->is_last, &iterator->type, &iterator->length)) {
2027                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2028                 return false;
2029         }
2030
2031         return true;
2032 }
2033
2034 FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block)
2035 {
2036         FLAC__ASSERT(0 != iterator);
2037         FLAC__ASSERT(0 != iterator->file);
2038
2039         iterator->status = read_metadata_block_data_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, block);
2040
2041         return (iterator->status == FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK);
2042 }
2043
2044 FLAC__bool read_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__bool *is_last, FLAC__MetadataType *type, unsigned *length)
2045 {
2046         FLAC__byte raw_header[FLAC__STREAM_METADATA_HEADER_LENGTH];
2047
2048         if(read_cb(raw_header, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
2049                 return false;
2050
2051         *is_last = raw_header[0] & 0x80? true : false;
2052         *type = (FLAC__MetadataType)(raw_header[0] & 0x7f);
2053         *length = unpack_uint32_(raw_header + 1, 3);
2054
2055         /* Note that we don't check:
2056          *    if(iterator->type >= FLAC__METADATA_TYPE_UNDEFINED)
2057          * we just will read in an opaque block
2058          */
2059
2060         return true;
2061 }
2062
2063 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata *block)
2064 {
2065         switch(block->type) {
2066                 case FLAC__METADATA_TYPE_STREAMINFO:
2067                         return read_metadata_block_data_streaminfo_cb_(handle, read_cb, &block->data.stream_info);
2068                 case FLAC__METADATA_TYPE_PADDING:
2069                         return read_metadata_block_data_padding_cb_(handle, seek_cb, &block->data.padding, block->length);
2070                 case FLAC__METADATA_TYPE_APPLICATION:
2071                         return read_metadata_block_data_application_cb_(handle, read_cb, &block->data.application, block->length);
2072                 case FLAC__METADATA_TYPE_SEEKTABLE:
2073                         return read_metadata_block_data_seektable_cb_(handle, read_cb, &block->data.seek_table, block->length);
2074                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
2075                         return read_metadata_block_data_vorbis_comment_cb_(handle, read_cb, &block->data.vorbis_comment);
2076                 case FLAC__METADATA_TYPE_CUESHEET:
2077                         return read_metadata_block_data_cuesheet_cb_(handle, read_cb, &block->data.cue_sheet);
2078                 case FLAC__METADATA_TYPE_PICTURE:
2079                         return read_metadata_block_data_picture_cb_(handle, read_cb, &block->data.picture);
2080                 default:
2081                         return read_metadata_block_data_unknown_cb_(handle, read_cb, &block->data.unknown, block->length);
2082         }
2083 }
2084
2085 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_StreamInfo *block)
2086 {
2087         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH], *b;
2088
2089         if(read_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
2090                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2091
2092         b = buffer;
2093
2094         /* we are using hardcoded numbers for simplicity but we should
2095          * probably eventually write a bit-level unpacker and use the
2096          * _STREAMINFO_ constants.
2097          */
2098         block->min_blocksize = unpack_uint32_(b, 2); b += 2;
2099         block->max_blocksize = unpack_uint32_(b, 2); b += 2;
2100         block->min_framesize = unpack_uint32_(b, 3); b += 3;
2101         block->max_framesize = unpack_uint32_(b, 3); b += 3;
2102         block->sample_rate = (unpack_uint32_(b, 2) << 4) | ((unsigned)(b[2] & 0xf0) >> 4);
2103         block->channels = (unsigned)((b[2] & 0x0e) >> 1) + 1;
2104         block->bits_per_sample = ((((unsigned)(b[2] & 0x01)) << 4) | (((unsigned)(b[3] & 0xf0)) >> 4)) + 1;
2105         block->total_samples = (((FLAC__uint64)(b[3] & 0x0f)) << 32) | unpack_uint64_(b+4, 4);
2106         memcpy(block->md5sum, b+8, 16);
2107
2108         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2109 }
2110
2111 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata_Padding *block, unsigned block_length)
2112 {
2113         (void)block; /* nothing to do; we don't care about reading the padding bytes */
2114
2115         if(0 != seek_cb(handle, block_length, SEEK_CUR))
2116                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2117
2118         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2119 }
2120
2121 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Application *block, unsigned block_length)
2122 {
2123         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
2124
2125         if(read_cb(block->id, 1, id_bytes, handle) != id_bytes)
2126                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2127
2128         block_length -= id_bytes;
2129
2130         if(block_length == 0) {
2131                 block->data = 0;
2132         }
2133         else {
2134                 if(0 == (block->data = (FLAC__byte*)malloc(block_length)))
2135                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2136
2137                 if(read_cb(block->data, 1, block_length, handle) != block_length)
2138                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2139         }
2140
2141         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2142 }
2143
2144 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_SeekTable *block, unsigned block_length)
2145 {
2146         unsigned i;
2147         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
2148
2149         FLAC__ASSERT(block_length % FLAC__STREAM_METADATA_SEEKPOINT_LENGTH == 0);
2150
2151         block->num_points = block_length / FLAC__STREAM_METADATA_SEEKPOINT_LENGTH;
2152
2153         if(block->num_points == 0)
2154                 block->points = 0;
2155         else if(0 == (block->points = (FLAC__StreamMetadata_SeekPoint*)malloc(block->num_points * sizeof(FLAC__StreamMetadata_SeekPoint))))
2156                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2157
2158         for(i = 0; i < block->num_points; i++) {
2159                 if(read_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
2160                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2161                 /* some MAGIC NUMBERs here */
2162                 block->points[i].sample_number = unpack_uint64_(buffer, 8);
2163                 block->points[i].stream_offset = unpack_uint64_(buffer+8, 8);
2164                 block->points[i].frame_samples = unpack_uint32_(buffer+16, 2);
2165         }
2166
2167         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2168 }
2169
2170 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_entry_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment_Entry *entry)
2171 {
2172         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
2173         FLAC__byte buffer[4]; /* magic number is asserted below */
2174
2175         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8 == sizeof(buffer));
2176
2177         if(read_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2178                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2179         entry->length = unpack_uint32_little_endian_(buffer, entry_length_len);
2180
2181         if(0 != entry->entry)
2182                 free(entry->entry);
2183
2184         if(entry->length == 0) {
2185                 entry->entry = 0;
2186         }
2187         else {
2188                 if(0 == (entry->entry = (FLAC__byte*)malloc(entry->length+1)))
2189                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2190
2191                 if(read_cb(entry->entry, 1, entry->length, handle) != entry->length)
2192                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2193
2194                 entry->entry[entry->length] = '\0';
2195         }
2196
2197         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2198 }
2199
2200 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment *block)
2201 {
2202         unsigned i;
2203         FLAC__Metadata_SimpleIteratorStatus status;
2204         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2205         FLAC__byte buffer[4]; /* magic number is asserted below */
2206
2207         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8 == sizeof(buffer));
2208
2209         if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, &(block->vendor_string))))
2210                 return status;
2211
2212         if(read_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2213                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2214         block->num_comments = unpack_uint32_little_endian_(buffer, num_comments_len);
2215
2216         if(block->num_comments == 0) {
2217                 block->comments = 0;
2218         }
2219         else if(0 == (block->comments = (FLAC__StreamMetadata_VorbisComment_Entry*)calloc(block->num_comments, sizeof(FLAC__StreamMetadata_VorbisComment_Entry))))
2220                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2221
2222         for(i = 0; i < block->num_comments; i++) {
2223                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, block->comments + i)))
2224                         return status;
2225         }
2226
2227         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2228 }
2229
2230 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet_Track *track)
2231 {
2232         unsigned i, len;
2233         FLAC__byte buffer[32]; /* asserted below that this is big enough */
2234
2235         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2236         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2237         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);
2238
2239         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2240         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2241         if(read_cb(buffer, 1, len, handle) != len)
2242                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2243         track->offset = unpack_uint64_(buffer, len);
2244
2245         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2246         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2247         if(read_cb(buffer, 1, len, handle) != len)
2248                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2249         track->number = (FLAC__byte)unpack_uint32_(buffer, len);
2250
2251         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2252         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2253         if(read_cb(track->isrc, 1, len, handle) != len)
2254                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2255
2256         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);
2257         len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2258         if(read_cb(buffer, 1, len, handle) != len)
2259                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2260         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN == 1);
2261         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN == 1);
2262         track->type = buffer[0] >> 7;
2263         track->pre_emphasis = (buffer[0] >> 6) & 1;
2264
2265         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2266         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2267         if(read_cb(buffer, 1, len, handle) != len)
2268                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2269         track->num_indices = (FLAC__byte)unpack_uint32_(buffer, len);
2270
2271         if(track->num_indices == 0) {
2272                 track->indices = 0;
2273         }
2274         else if(0 == (track->indices = (FLAC__StreamMetadata_CueSheet_Index*)calloc(track->num_indices, sizeof(FLAC__StreamMetadata_CueSheet_Index))))
2275                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2276
2277         for(i = 0; i < track->num_indices; i++) {
2278                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2279                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2280                 if(read_cb(buffer, 1, len, handle) != len)
2281                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2282                 track->indices[i].offset = unpack_uint64_(buffer, len);
2283
2284                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2285                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2286                 if(read_cb(buffer, 1, len, handle) != len)
2287                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2288                 track->indices[i].number = (FLAC__byte)unpack_uint32_(buffer, len);
2289
2290                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2291                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2292                 if(read_cb(buffer, 1, len, handle) != len)
2293                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2294         }
2295
2296         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2297 }
2298
2299 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet *block)
2300 {
2301         unsigned i, len;
2302         FLAC__Metadata_SimpleIteratorStatus status;
2303         FLAC__byte buffer[1024]; /* MSVC needs a constant expression so we put a magic number and assert */
2304
2305         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN)/8 <= sizeof(buffer));
2306         FLAC__ASSERT(sizeof(FLAC__uint64) <= sizeof(buffer));
2307
2308         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2309         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2310         if(read_cb(block->media_catalog_number, 1, len, handle) != len)
2311                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2312
2313         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2314         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2315         if(read_cb(buffer, 1, len, handle) != len)
2316                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2317         block->lead_in = unpack_uint64_(buffer, len);
2318
2319         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2320         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2321         if(read_cb(buffer, 1, len, handle) != len)
2322                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2323         block->is_cd = buffer[0]&0x80? true : false;
2324
2325         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2326         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2327         if(read_cb(buffer, 1, len, handle) != len)
2328                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2329         block->num_tracks = unpack_uint32_(buffer, len);
2330
2331         if(block->num_tracks == 0) {
2332                 block->tracks = 0;
2333         }
2334         else if(0 == (block->tracks = (FLAC__StreamMetadata_CueSheet_Track*)calloc(block->num_tracks, sizeof(FLAC__StreamMetadata_CueSheet_Track))))
2335                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2336
2337         for(i = 0; i < block->num_tracks; i++) {
2338                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_cuesheet_track_cb_(handle, read_cb, block->tracks + i)))
2339                         return status;
2340         }
2341
2342         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2343 }
2344
2345 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)
2346 {
2347         FLAC__byte buffer[sizeof(FLAC__uint32)];
2348
2349         FLAC__ASSERT(0 != data);
2350         FLAC__ASSERT(length_len%8 == 0);
2351
2352         length_len /= 8; /* convert to bytes */
2353
2354         FLAC__ASSERT(sizeof(buffer) >= length_len);
2355
2356         if(read_cb(buffer, 1, length_len, handle) != length_len)
2357                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2358         *length = unpack_uint32_(buffer, length_len);
2359
2360         if(0 != *data)
2361                 free(*data);
2362
2363         if(0 == (*data = (FLAC__byte*)malloc(*length+1)))
2364                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2365
2366         if(*length > 0) {
2367                 if(read_cb(*data, 1, *length, handle) != *length)
2368                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2369         }
2370
2371         (*data)[*length] = '\0';
2372
2373         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2374 }
2375
2376 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Picture *block)
2377 {
2378         FLAC__Metadata_SimpleIteratorStatus status;
2379         FLAC__byte buffer[4]; /* asserted below that this is big enough */
2380         FLAC__uint32 len;
2381
2382         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8);
2383         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8);
2384         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8);
2385         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8);
2386         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8);
2387
2388         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_TYPE_LEN % 8 == 0);
2389         len = FLAC__STREAM_METADATA_PICTURE_TYPE_LEN / 8;
2390         if(read_cb(buffer, 1, len, handle) != len)
2391                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2392         block->type = (FLAC__StreamMetadata_Picture_Type)unpack_uint32_(buffer, len);
2393
2394         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)
2395                 return status;
2396
2397         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)
2398                 return status;
2399
2400         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN % 8 == 0);
2401         len = FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN / 8;
2402         if(read_cb(buffer, 1, len, handle) != len)
2403                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2404         block->width = unpack_uint32_(buffer, len);
2405
2406         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN % 8 == 0);
2407         len = FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN / 8;
2408         if(read_cb(buffer, 1, len, handle) != len)
2409                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2410         block->height = unpack_uint32_(buffer, len);
2411
2412         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN % 8 == 0);
2413         len = FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN / 8;
2414         if(read_cb(buffer, 1, len, handle) != len)
2415                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2416         block->depth = unpack_uint32_(buffer, len);
2417
2418         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_COLORS_LEN % 8 == 0);
2419         len = FLAC__STREAM_METADATA_PICTURE_COLORS_LEN / 8;
2420         if(read_cb(buffer, 1, len, handle) != len)
2421                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2422         block->colors = unpack_uint32_(buffer, len);
2423
2424         /* for convenience we use read_metadata_block_data_picture_cstring_cb_() even though it adds an extra terminating NUL we don't use */
2425         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)
2426                 return status;
2427
2428         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2429 }
2430
2431 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2432 {
2433         if(block_length == 0) {
2434                 block->data = 0;
2435         }
2436         else {
2437                 if(0 == (block->data = (FLAC__byte*)malloc(block_length)))
2438                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2439
2440                 if(read_cb(block->data, 1, block_length, handle) != block_length)
2441                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2442         }
2443
2444         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2445 }
2446
2447 FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2448 {
2449         FLAC__ASSERT(0 != file);
2450         FLAC__ASSERT(0 != status);
2451
2452         if(!write_metadata_block_header_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2453                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2454                 return false;
2455         }
2456
2457         return true;
2458 }
2459
2460 FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2461 {
2462         FLAC__ASSERT(0 != file);
2463         FLAC__ASSERT(0 != status);
2464
2465         if (write_metadata_block_data_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2466                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2467                 return true;
2468         }
2469         else {
2470                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2471                 return false;
2472         }
2473 }
2474
2475 FLAC__bool write_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2476 {
2477         FLAC__byte buffer[FLAC__STREAM_METADATA_HEADER_LENGTH];
2478
2479         FLAC__ASSERT(block->length < (1u << FLAC__STREAM_METADATA_LENGTH_LEN));
2480
2481         buffer[0] = (block->is_last? 0x80 : 0) | (FLAC__byte)block->type;
2482         pack_uint32_(block->length, buffer + 1, 3);
2483
2484         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
2485                 return false;
2486
2487         return true;
2488 }
2489
2490 FLAC__bool write_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2491 {
2492         FLAC__ASSERT(0 != block);
2493
2494         switch(block->type) {
2495                 case FLAC__METADATA_TYPE_STREAMINFO:
2496                         return write_metadata_block_data_streaminfo_cb_(handle, write_cb, &block->data.stream_info);
2497                 case FLAC__METADATA_TYPE_PADDING:
2498                         return write_metadata_block_data_padding_cb_(handle, write_cb, &block->data.padding, block->length);
2499                 case FLAC__METADATA_TYPE_APPLICATION:
2500                         return write_metadata_block_data_application_cb_(handle, write_cb, &block->data.application, block->length);
2501                 case FLAC__METADATA_TYPE_SEEKTABLE:
2502                         return write_metadata_block_data_seektable_cb_(handle, write_cb, &block->data.seek_table);
2503                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
2504                         return write_metadata_block_data_vorbis_comment_cb_(handle, write_cb, &block->data.vorbis_comment);
2505                 case FLAC__METADATA_TYPE_CUESHEET:
2506                         return write_metadata_block_data_cuesheet_cb_(handle, write_cb, &block->data.cue_sheet);
2507                 case FLAC__METADATA_TYPE_PICTURE:
2508                         return write_metadata_block_data_picture_cb_(handle, write_cb, &block->data.picture);
2509                 default:
2510                         return write_metadata_block_data_unknown_cb_(handle, write_cb, &block->data.unknown, block->length);
2511         }
2512 }
2513
2514 FLAC__bool write_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_StreamInfo *block)
2515 {
2516         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH];
2517         const unsigned channels1 = block->channels - 1;
2518         const unsigned bps1 = block->bits_per_sample - 1;
2519
2520         /* we are using hardcoded numbers for simplicity but we should
2521          * probably eventually write a bit-level packer and use the
2522          * _STREAMINFO_ constants.
2523          */
2524         pack_uint32_(block->min_blocksize, buffer, 2);
2525         pack_uint32_(block->max_blocksize, buffer+2, 2);
2526         pack_uint32_(block->min_framesize, buffer+4, 3);
2527         pack_uint32_(block->max_framesize, buffer+7, 3);
2528         buffer[10] = (block->sample_rate >> 12) & 0xff;
2529         buffer[11] = (block->sample_rate >> 4) & 0xff;
2530         buffer[12] = ((block->sample_rate & 0x0f) << 4) | (channels1 << 1) | (bps1 >> 4);
2531         buffer[13] = (FLAC__byte)(((bps1 & 0x0f) << 4) | ((block->total_samples >> 32) & 0x0f));
2532         pack_uint32_((FLAC__uint32)block->total_samples, buffer+14, 4);
2533         memcpy(buffer+18, block->md5sum, 16);
2534
2535         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
2536                 return false;
2537
2538         return true;
2539 }
2540
2541 FLAC__bool write_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Padding *block, unsigned block_length)
2542 {
2543         unsigned i, n = block_length;
2544         FLAC__byte buffer[1024];
2545
2546         (void)block;
2547
2548         memset(buffer, 0, 1024);
2549
2550         for(i = 0; i < n/1024; i++)
2551                 if(write_cb(buffer, 1, 1024, handle) != 1024)
2552                         return false;
2553
2554         n %= 1024;
2555
2556         if(write_cb(buffer, 1, n, handle) != n)
2557                 return false;
2558
2559         return true;
2560 }
2561
2562 FLAC__bool write_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Application *block, unsigned block_length)
2563 {
2564         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
2565
2566         if(write_cb(block->id, 1, id_bytes, handle) != id_bytes)
2567                 return false;
2568
2569         block_length -= id_bytes;
2570
2571         if(write_cb(block->data, 1, block_length, handle) != block_length)
2572                 return false;
2573
2574         return true;
2575 }
2576
2577 FLAC__bool write_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_SeekTable *block)
2578 {
2579         unsigned i;
2580         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
2581
2582         for(i = 0; i < block->num_points; i++) {
2583                 /* some MAGIC NUMBERs here */
2584                 pack_uint64_(block->points[i].sample_number, buffer, 8);
2585                 pack_uint64_(block->points[i].stream_offset, buffer+8, 8);
2586                 pack_uint32_(block->points[i].frame_samples, buffer+16, 2);
2587                 if(write_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
2588                         return false;
2589         }
2590
2591         return true;
2592 }
2593
2594 FLAC__bool write_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_VorbisComment *block)
2595 {
2596         unsigned i;
2597         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
2598         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2599         FLAC__byte buffer[4]; /* magic number is asserted below */
2600
2601         FLAC__ASSERT(max(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN, FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN) / 8 == sizeof(buffer));
2602
2603         pack_uint32_little_endian_(block->vendor_string.length, buffer, entry_length_len);
2604         if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2605                 return false;
2606         if(write_cb(block->vendor_string.entry, 1, block->vendor_string.length, handle) != block->vendor_string.length)
2607                 return false;
2608
2609         pack_uint32_little_endian_(block->num_comments, buffer, num_comments_len);
2610         if(write_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2611                 return false;
2612
2613         for(i = 0; i < block->num_comments; i++) {
2614                 pack_uint32_little_endian_(block->comments[i].length, buffer, entry_length_len);
2615                 if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2616                         return false;
2617                 if(write_cb(block->comments[i].entry, 1, block->comments[i].length, handle) != block->comments[i].length)
2618                         return false;
2619         }
2620
2621         return true;
2622 }
2623
2624 FLAC__bool write_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_CueSheet *block)
2625 {
2626         unsigned i, j, len;
2627         FLAC__byte buffer[1024]; /* asserted below that this is big enough */
2628
2629         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2630         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN/8);
2631         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);
2632         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2633
2634         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2635         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2636         if(write_cb(block->media_catalog_number, 1, len, handle) != len)
2637                 return false;
2638
2639         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2640         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2641         pack_uint64_(block->lead_in, buffer, len);
2642         if(write_cb(buffer, 1, len, handle) != len)
2643                 return false;
2644
2645         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2646         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2647         memset(buffer, 0, len);
2648         if(block->is_cd)
2649                 buffer[0] |= 0x80;
2650         if(write_cb(buffer, 1, len, handle) != len)
2651                 return false;
2652
2653         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2654         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2655         pack_uint32_(block->num_tracks, buffer, len);
2656         if(write_cb(buffer, 1, len, handle) != len)
2657                 return false;
2658
2659         for(i = 0; i < block->num_tracks; i++) {
2660                 FLAC__StreamMetadata_CueSheet_Track *track = block->tracks + i;
2661
2662                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2663                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2664                 pack_uint64_(track->offset, buffer, len);
2665                 if(write_cb(buffer, 1, len, handle) != len)
2666                         return false;
2667
2668                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2669                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2670                 pack_uint32_(track->number, buffer, len);
2671                 if(write_cb(buffer, 1, len, handle) != len)
2672                         return false;
2673
2674                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2675                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2676                 if(write_cb(track->isrc, 1, len, handle) != len)
2677                         return false;
2678
2679                 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);
2680                 len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2681                 memset(buffer, 0, len);
2682                 buffer[0] = (track->type << 7) | (track->pre_emphasis << 6);
2683                 if(write_cb(buffer, 1, len, handle) != len)
2684                         return false;
2685
2686                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2687                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2688                 pack_uint32_(track->num_indices, buffer, len);
2689                 if(write_cb(buffer, 1, len, handle) != len)
2690                         return false;
2691
2692                 for(j = 0; j < track->num_indices; j++) {
2693                         FLAC__StreamMetadata_CueSheet_Index *index = track->indices + j;
2694
2695                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2696                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2697                         pack_uint64_(index->offset, buffer, len);
2698                         if(write_cb(buffer, 1, len, handle) != len)
2699                                 return false;
2700
2701                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2702                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2703                         pack_uint32_(index->number, buffer, len);
2704                         if(write_cb(buffer, 1, len, handle) != len)
2705                                 return false;
2706
2707                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2708                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2709                         memset(buffer, 0, len);
2710                         if(write_cb(buffer, 1, len, handle) != len)
2711                                 return false;
2712                 }
2713         }
2714
2715         return true;
2716 }
2717
2718 FLAC__bool write_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Picture *block)
2719 {
2720         unsigned len;
2721         size_t slen;
2722         FLAC__byte buffer[4]; /* magic number is asserted below */
2723
2724         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_TYPE_LEN%8);
2725         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN%8);
2726         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN%8);
2727         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN%8);
2728         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN%8);
2729         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN%8);
2730         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_COLORS_LEN%8);
2731         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN%8);
2732         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8);
2733         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN/8);
2734         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN/8);
2735         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8);
2736         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8);
2737         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8);
2738         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8);
2739         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN/8);
2740
2741         len = FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8;
2742         pack_uint32_(block->type, buffer, len);
2743         if(write_cb(buffer, 1, len, handle) != len)
2744                 return false;
2745
2746         len = FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN/8;
2747         slen = strlen(block->mime_type);
2748         pack_uint32_(slen, buffer, len);
2749         if(write_cb(buffer, 1, len, handle) != len)
2750                 return false;
2751         if(write_cb(block->mime_type, 1, slen, handle) != slen)
2752                 return false;
2753
2754         len = FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN/8;
2755         slen = strlen((const char *)block->description);
2756         pack_uint32_(slen, buffer, len);
2757         if(write_cb(buffer, 1, len, handle) != len)
2758                 return false;
2759         if(write_cb(block->description, 1, slen, handle) != slen)
2760                 return false;
2761
2762         len = FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8;
2763         pack_uint32_(block->width, buffer, len);
2764         if(write_cb(buffer, 1, len, handle) != len)
2765                 return false;
2766
2767         len = FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8;
2768         pack_uint32_(block->height, buffer, len);
2769         if(write_cb(buffer, 1, len, handle) != len)
2770                 return false;
2771
2772         len = FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8;
2773         pack_uint32_(block->depth, buffer, len);
2774         if(write_cb(buffer, 1, len, handle) != len)
2775                 return false;
2776
2777         len = FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8;
2778         pack_uint32_(block->colors, buffer, len);
2779         if(write_cb(buffer, 1, len, handle) != len)
2780                 return false;
2781
2782         len = FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN/8;
2783         pack_uint32_(block->data_length, buffer, len);
2784         if(write_cb(buffer, 1, len, handle) != len)
2785                 return false;
2786         if(write_cb(block->data, 1, block->data_length, handle) != block->data_length)
2787                 return false;
2788
2789         return true;
2790 }
2791
2792 FLAC__bool write_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2793 {
2794         if(write_cb(block->data, 1, block_length, handle) != block_length)
2795                 return false;
2796
2797         return true;
2798 }
2799
2800 FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block)
2801 {
2802         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2803                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2804                 return false;
2805         }
2806
2807         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2808                 return false;
2809
2810         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2811                 return false;
2812
2813         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2814                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2815                 return false;
2816         }
2817
2818         return read_metadata_block_header_(iterator);
2819 }
2820
2821 FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last)
2822 {
2823         FLAC__StreamMetadata *padding;
2824
2825         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2826                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2827                 return false;
2828         }
2829
2830         block->is_last = false;
2831
2832         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2833                 return false;
2834
2835         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2836                 return false;
2837
2838         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING)))
2839                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2840
2841         padding->is_last = padding_is_last;
2842         padding->length = padding_length;
2843
2844         if(!write_metadata_block_header_(iterator->file, &iterator->status, padding)) {
2845                 FLAC__metadata_object_delete(padding);
2846                 return false;
2847         }
2848
2849         if(!write_metadata_block_data_(iterator->file, &iterator->status, padding)) {
2850                 FLAC__metadata_object_delete(padding);
2851                 return false;
2852         }
2853
2854         FLAC__metadata_object_delete(padding);
2855
2856         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2857                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2858                 return false;
2859         }
2860
2861         return read_metadata_block_header_(iterator);
2862 }
2863
2864 FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append)
2865 {
2866         FILE *tempfile;
2867         char *tempfilename;
2868         int fixup_is_last_code = 0; /* 0 => no need to change any is_last flags */
2869         off_t fixup_is_last_flag_offset = -1;
2870
2871         FLAC__ASSERT(0 != block || append == false);
2872
2873         if(iterator->is_last) {
2874                 if(append) {
2875                         fixup_is_last_code = 1; /* 1 => clear the is_last flag at the following offset */
2876                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2877                 }
2878                 else if(0 == block) {
2879                         simple_iterator_push_(iterator);
2880                         if(!FLAC__metadata_simple_iterator_prev(iterator)) {
2881                                 (void)simple_iterator_pop_(iterator);
2882                                 return false;
2883                         }
2884                         fixup_is_last_code = -1; /* -1 => set the is_last the flag at the following offset */
2885                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2886                         if(!simple_iterator_pop_(iterator))
2887                                 return false;
2888                 }
2889         }
2890
2891         if(!simple_iterator_copy_file_prefix_(iterator, &tempfile, &tempfilename, append))
2892                 return false;
2893
2894         if(0 != block) {
2895                 if(!write_metadata_block_header_(tempfile, &iterator->status, block)) {
2896                         cleanup_tempfile_(&tempfile, &tempfilename);
2897                         return false;
2898                 }
2899
2900                 if(!write_metadata_block_data_(tempfile, &iterator->status, block)) {
2901                         cleanup_tempfile_(&tempfile, &tempfilename);
2902                         return false;
2903                 }
2904         }
2905
2906         if(!simple_iterator_copy_file_postfix_(iterator, &tempfile, &tempfilename, fixup_is_last_code, fixup_is_last_flag_offset, block==0))
2907                 return false;
2908
2909         if(append)
2910                 return FLAC__metadata_simple_iterator_next(iterator);
2911
2912         return true;
2913 }
2914
2915 void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator)
2916 {
2917         FLAC__ASSERT(iterator->depth+1 < SIMPLE_ITERATOR_MAX_PUSH_DEPTH);
2918         iterator->offset[iterator->depth+1] = iterator->offset[iterator->depth];
2919         iterator->depth++;
2920 }
2921
2922 FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator)
2923 {
2924         FLAC__ASSERT(iterator->depth > 0);
2925         iterator->depth--;
2926         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2927                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2928                 return false;
2929         }
2930
2931         return read_metadata_block_header_(iterator);
2932 }
2933
2934 /* return meanings:
2935  * 0: ok
2936  * 1: read error
2937  * 2: seek error
2938  * 3: not a FLAC file
2939  */
2940 unsigned seek_to_first_metadata_block_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb)
2941 {
2942         FLAC__byte buffer[4];
2943         size_t n;
2944         unsigned i;
2945
2946         FLAC__ASSERT(FLAC__STREAM_SYNC_LENGTH == sizeof(buffer));
2947
2948         /* skip any id3v2 tag */
2949         errno = 0;
2950         n = read_cb(buffer, 1, 4, handle);
2951         if(errno)
2952                 return 1;
2953         else if(n != 4)
2954                 return 3;
2955         else if(0 == memcmp(buffer, "ID3", 3)) {
2956                 unsigned tag_length = 0;
2957
2958                 /* skip to the tag length */
2959                 if(seek_cb(handle, 2, SEEK_CUR) < 0)
2960                         return 2;
2961
2962                 /* read the length */
2963                 for(i = 0; i < 4; i++) {
2964                         if(read_cb(buffer, 1, 1, handle) < 1 || buffer[0] & 0x80)
2965                                 return 1;
2966                         tag_length <<= 7;
2967                         tag_length |= (buffer[0] & 0x7f);
2968                 }
2969
2970                 /* skip the rest of the tag */
2971                 if(seek_cb(handle, tag_length, SEEK_CUR) < 0)
2972                         return 2;
2973
2974                 /* read the stream sync code */
2975                 errno = 0;
2976                 n = read_cb(buffer, 1, 4, handle);
2977                 if(errno)
2978                         return 1;
2979                 else if(n != 4)
2980                         return 3;
2981         }
2982
2983         /* check for the fLaC signature */
2984         if(0 == memcmp(FLAC__STREAM_SYNC_STRING, buffer, FLAC__STREAM_SYNC_LENGTH))
2985                 return 0;
2986         else
2987                 return 3;
2988 }
2989
2990 unsigned seek_to_first_metadata_block_(FILE *f)
2991 {
2992         return seek_to_first_metadata_block_cb_((FLAC__IOHandle)f, (FLAC__IOCallback_Read)fread, fseek_wrapper_);
2993 }
2994
2995 FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append)
2996 {
2997         const off_t offset_end = append? iterator->offset[iterator->depth] + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length : iterator->offset[iterator->depth];
2998
2999         if(0 != fseeko(iterator->file, 0, SEEK_SET)) {
3000                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3001                 return false;
3002         }
3003         if(!open_tempfile_(iterator->filename, iterator->tempfile_path_prefix, tempfile, tempfilename, &iterator->status)) {
3004                 cleanup_tempfile_(tempfile, tempfilename);
3005                 return false;
3006         }
3007         if(!copy_n_bytes_from_file_(iterator->file, *tempfile, offset_end, &iterator->status)) {
3008                 cleanup_tempfile_(tempfile, tempfilename);
3009                 return false;
3010         }
3011
3012         return true;
3013 }
3014
3015 FLAC__bool simple_iterator_copy_file_postfix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, int fixup_is_last_code, off_t fixup_is_last_flag_offset, FLAC__bool backup)
3016 {
3017         off_t save_offset = iterator->offset[iterator->depth];
3018         FLAC__ASSERT(0 != *tempfile);
3019
3020         if(0 != fseeko(iterator->file, save_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length, SEEK_SET)) {
3021                 cleanup_tempfile_(tempfile, tempfilename);
3022                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3023                 return false;
3024         }
3025         if(!copy_remaining_bytes_from_file_(iterator->file, *tempfile, &iterator->status)) {
3026                 cleanup_tempfile_(tempfile, tempfilename);
3027                 return false;
3028         }
3029
3030         if(fixup_is_last_code != 0) {
3031                 /*
3032                  * if code == 1, it means a block was appended to the end so
3033                  *   we have to clear the is_last flag of the previous block
3034                  * if code == -1, it means the last block was deleted so
3035                  *   we have to set the is_last flag of the previous block
3036                  */
3037                 /* MAGIC NUMBERs here; we know the is_last flag is the high bit of the byte at this location */
3038                 FLAC__byte x;
3039                 if(0 != fseeko(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
3040                         cleanup_tempfile_(tempfile, tempfilename);
3041                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3042                         return false;
3043                 }
3044                 if(fread(&x, 1, 1, *tempfile) != 1) {
3045                         cleanup_tempfile_(tempfile, tempfilename);
3046                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3047                         return false;
3048                 }
3049                 if(fixup_is_last_code > 0) {
3050                         FLAC__ASSERT(x & 0x80);
3051                         x &= 0x7f;
3052                 }
3053                 else {
3054                         FLAC__ASSERT(!(x & 0x80));
3055                         x |= 0x80;
3056                 }
3057                 if(0 != fseeko(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
3058                         cleanup_tempfile_(tempfile, tempfilename);
3059                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3060                         return false;
3061                 }
3062                 if(local__fwrite(&x, 1, 1, *tempfile) != 1) {
3063                         cleanup_tempfile_(tempfile, tempfilename);
3064                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3065                         return false;
3066                 }
3067         }
3068
3069         (void)fclose(iterator->file);
3070
3071         if(!transport_tempfile_(iterator->filename, tempfile, tempfilename, &iterator->status))
3072                 return false;
3073
3074         if(iterator->has_stats)
3075                 set_file_stats_(iterator->filename, &iterator->stats);
3076
3077         if(!simple_iterator_prime_input_(iterator, !iterator->is_writable))
3078                 return false;
3079         if(backup) {
3080                 while(iterator->offset[iterator->depth] + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length < save_offset)
3081                         if(!FLAC__metadata_simple_iterator_next(iterator))
3082                                 return false;
3083                 return true;
3084         }
3085         else {
3086                 /* move the iterator to it's original block faster by faking a push, then doing a pop_ */
3087                 FLAC__ASSERT(iterator->depth == 0);
3088                 iterator->offset[0] = save_offset;
3089                 iterator->depth++;
3090                 return simple_iterator_pop_(iterator);
3091         }
3092 }
3093
3094 FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status)
3095 {
3096         FLAC__byte buffer[8192];
3097         size_t n;
3098
3099         FLAC__ASSERT(bytes >= 0);
3100         while(bytes > 0) {
3101                 n = min(sizeof(buffer), (size_t)bytes);
3102                 if(fread(buffer, 1, n, file) != n) {
3103                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3104                         return false;
3105                 }
3106                 if(local__fwrite(buffer, 1, n, tempfile) != n) {
3107                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3108                         return false;
3109                 }
3110                 bytes -= n;
3111         }
3112
3113         return true;
3114 }
3115
3116 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, off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status)
3117 {
3118         FLAC__byte buffer[8192];
3119         size_t n;
3120
3121         FLAC__ASSERT(bytes >= 0);
3122         while(bytes > 0) {
3123                 n = min(sizeof(buffer), (size_t)bytes);
3124                 if(read_cb(buffer, 1, n, handle) != n) {
3125                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3126                         return false;
3127                 }
3128                 if(temp_write_cb(buffer, 1, n, temp_handle) != n) {
3129                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3130                         return false;
3131                 }
3132                 bytes -= n;
3133         }
3134
3135         return true;
3136 }
3137
3138 FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status)
3139 {
3140         FLAC__byte buffer[8192];
3141         size_t n;
3142
3143         while(!feof(file)) {
3144                 n = fread(buffer, 1, sizeof(buffer), file);
3145                 if(n == 0 && !feof(file)) {
3146                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3147                         return false;
3148                 }
3149                 if(n > 0 && local__fwrite(buffer, 1, n, tempfile) != n) {
3150                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3151                         return false;
3152                 }
3153         }
3154
3155         return true;
3156 }
3157
3158 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)
3159 {
3160         FLAC__byte buffer[8192];
3161         size_t n;
3162
3163         while(!eof_cb(handle)) {
3164                 n = read_cb(buffer, 1, sizeof(buffer), handle);
3165                 if(n == 0 && !eof_cb(handle)) {
3166                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3167                         return false;
3168                 }
3169                 if(n > 0 && temp_write_cb(buffer, 1, n, temp_handle) != n) {
3170                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3171                         return false;
3172                 }
3173         }
3174
3175         return true;
3176 }
3177
3178 FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
3179 {
3180         static const char *tempfile_suffix = ".metadata_edit";
3181         if(0 == tempfile_path_prefix) {
3182                 if(0 == (*tempfilename = (char*)malloc(strlen(filename) + strlen(tempfile_suffix) + 1))) {
3183                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
3184                         return false;
3185                 }
3186                 strcpy(*tempfilename, filename);
3187                 strcat(*tempfilename, tempfile_suffix);
3188         }
3189         else {
3190                 const char *p = strrchr(filename, '/');
3191                 if(0 == p)
3192                         p = filename;
3193                 else
3194                         p++;
3195
3196                 if(0 == (*tempfilename = (char*)malloc(strlen(tempfile_path_prefix) + 1 + strlen(p) + strlen(tempfile_suffix) + 1))) {
3197                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
3198                         return false;
3199                 }
3200                 strcpy(*tempfilename, tempfile_path_prefix);
3201                 strcat(*tempfilename, "/");
3202                 strcat(*tempfilename, p);
3203                 strcat(*tempfilename, tempfile_suffix);
3204         }
3205
3206         if(0 == (*tempfile = fopen(*tempfilename, "w+b"))) {
3207                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
3208                 return false;
3209         }
3210
3211         return true;
3212 }
3213
3214 FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
3215 {
3216         FLAC__ASSERT(0 != filename);
3217         FLAC__ASSERT(0 != tempfile);
3218         FLAC__ASSERT(0 != *tempfile);
3219         FLAC__ASSERT(0 != tempfilename);
3220         FLAC__ASSERT(0 != *tempfilename);
3221         FLAC__ASSERT(0 != status);
3222
3223         (void)fclose(*tempfile);
3224         *tempfile = 0;
3225
3226 #if defined _MSC_VER || defined __BORLANDC__ || defined __MINGW32__ || defined __EMX__
3227         /* on some flavors of windows, rename() will fail if the destination already exists */
3228         if(unlink(filename) < 0) {
3229                 cleanup_tempfile_(tempfile, tempfilename);
3230                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR;
3231                 return false;
3232         }
3233 #endif
3234
3235         /*@@@ to fully support the tempfile_path_prefix we need to update this piece to actually copy across filesystems instead of just rename(): */
3236         if(0 != rename(*tempfilename, filename)) {
3237                 cleanup_tempfile_(tempfile, tempfilename);
3238                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR;
3239                 return false;
3240         }
3241
3242         cleanup_tempfile_(tempfile, tempfilename);
3243
3244         return true;
3245 }
3246
3247 void cleanup_tempfile_(FILE **tempfile, char **tempfilename)
3248 {
3249         if(0 != *tempfile) {
3250                 (void)fclose(*tempfile);
3251                 *tempfile = 0;
3252         }
3253
3254         if(0 != *tempfilename) {
3255                 (void)unlink(*tempfilename);
3256                 free(*tempfilename);
3257                 *tempfilename = 0;
3258         }
3259 }
3260
3261 FLAC__bool get_file_stats_(const char *filename, struct stat *stats)
3262 {
3263         FLAC__ASSERT(0 != filename);
3264         FLAC__ASSERT(0 != stats);
3265         return (0 == stat(filename, stats));
3266 }
3267
3268 void set_file_stats_(const char *filename, struct stat *stats)
3269 {
3270         struct utimbuf srctime;
3271
3272         FLAC__ASSERT(0 != filename);
3273         FLAC__ASSERT(0 != stats);
3274
3275         srctime.actime = stats->st_atime;
3276         srctime.modtime = stats->st_mtime;
3277         (void)chmod(filename, stats->st_mode);
3278         (void)utime(filename, &srctime);
3279 #if !defined _MSC_VER && !defined __BORLANDC__ && !defined __MINGW32__ && !defined __EMX__
3280         (void)chown(filename, stats->st_uid, -1);
3281         (void)chown(filename, -1, stats->st_gid);
3282 #endif
3283 }
3284
3285 int fseek_wrapper_(FLAC__IOHandle handle, FLAC__int64 offset, int whence)
3286 {
3287         return fseeko((FILE*)handle, (off_t)offset, whence);
3288 }
3289
3290 FLAC__int64 ftell_wrapper_(FLAC__IOHandle handle)
3291 {
3292         return ftello((FILE*)handle);
3293 }
3294
3295 FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status)
3296 {
3297         switch(status) {
3298                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK:
3299                         return FLAC__METADATA_CHAIN_STATUS_OK;
3300                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT:
3301                         return FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT;
3302                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE:
3303                         return FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
3304                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE:
3305                         return FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE;
3306                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE:
3307                         return FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE;
3308                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA:
3309                         return FLAC__METADATA_CHAIN_STATUS_BAD_METADATA;
3310                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR:
3311                         return FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
3312                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR:
3313                         return FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
3314                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR:
3315                         return FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
3316                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR:
3317                         return FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR;
3318                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR:
3319                         return FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR;
3320                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR:
3321                         return FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
3322                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR:
3323                 default:
3324                         return FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
3325         }
3326 }