src/libFLAC/metadata_iterators.c

   1 /* libFLAC - Free Lossless Audio Codec library
   2  * Copyright (C) 2001,2002,2003,2004  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 #include <errno.h>
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <string.h>
  36
  37 #if defined _MSC_VER || defined __MINGW32__
  38 #include <sys/utime.h> /* for utime() */
  39 #include <io.h> /* for chmod() */
  40 #else
  41 #include <sys/types.h> /* some flavors of BSD (like OS X) require this to get time_t */
  42 #include <utime.h> /* for utime() */
  43 #include <unistd.h> /* for chown(), unlink() */
  44 #endif
  45 #include <sys/stat.h> /* for stat(), maybe chmod() */
  46
  47 #include "private/metadata.h"
  48
  49 #include "FLAC/assert.h"
  50 #include "FLAC/file_decoder.h"
  51
  52 #ifdef max
  53 #undef max
  54 #endif
  55 #define max(a,b) ((a)>(b)?(a):(b))
  56 #ifdef min
  57 #undef min
  58 #endif
  59 #define min(a,b) ((a)<(b)?(a):(b))
  60
  61
  62 /****************************************************************************
  63  *
  64  * Local function declarations
  65  *
  66  ***************************************************************************/
  67
  68 static void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes);
  69 static void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes);
  70 static void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes);
  71 static FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes);
  72 static FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes);
  73 static FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes);
  74
  75 static FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator);
  76 static FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block);
  77 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_(FILE *file, FLAC__StreamMetadata_StreamInfo *block);
  78 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_padding_(FILE *file, FLAC__StreamMetadata_Padding *block, unsigned block_length);
  79 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_application_(FILE *file, FLAC__StreamMetadata_Application *block, unsigned block_length);
  80 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_seektable_(FILE *file, FLAC__StreamMetadata_SeekTable *block, unsigned block_length);
  81 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_entry_(FILE *file, FLAC__StreamMetadata_VorbisComment_Entry *entry);
  82 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_(FILE *file, FLAC__StreamMetadata_VorbisComment *block);
  83 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_(FILE *file, FLAC__StreamMetadata_CueSheet_Track *track);
  84 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_(FILE *file, FLAC__StreamMetadata_CueSheet *block);
  85 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_unknown_(FILE *file, FLAC__StreamMetadata_Unknown *block, unsigned block_length);
  86
  87 static FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block);
  88 static FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block);
  89 static FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_streaminfo_(FILE *file, const FLAC__StreamMetadata_StreamInfo *block);
  90 static FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_padding_(FILE *file, const FLAC__StreamMetadata_Padding *block, unsigned block_length);
  91 static FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_application_(FILE *file, const FLAC__StreamMetadata_Application *block, unsigned block_length);
  92 static FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_seektable_(FILE *file, const FLAC__StreamMetadata_SeekTable *block);
  93 static FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_vorbis_comment_(FILE *file, const FLAC__StreamMetadata_VorbisComment *block);
  94 static FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_cuesheet_(FILE *file, const FLAC__StreamMetadata_CueSheet *block);
  95 static FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_unknown_(FILE *file, const FLAC__StreamMetadata_Unknown *block, unsigned block_length);
  96 static FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block);
  97 static FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last);
  98 static FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append);
  99
 100 static FLAC__bool chain_rewrite_chain_(FLAC__Metadata_Chain *chain);
 101 static FLAC__bool chain_rewrite_file_(FLAC__Metadata_Chain *chain, const char *tempfile_path_prefix);
 102
 103 static void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator);
 104 static FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator);
 105
 106 /* return 0 if OK, 1 if read error, 2 if not a FLAC file */
 107 static unsigned seek_to_first_metadata_block_(FILE *f);
 108
 109 static FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append);
 110 static FLAC__bool simple_iterator_copy_file_postfix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, int fixup_is_last_code, long fixup_is_last_flag_offset, FLAC__bool backup);
 111
 112 static FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, unsigned bytes/*@@@ 4G limit*/, FLAC__Metadata_SimpleIteratorStatus *status);
 113 static FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status);
 114
 115 static FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status);
 116 static FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status);
 117 static void cleanup_tempfile_(FILE **tempfile, char **tempfilename);
 118
 119 static FLAC__bool get_file_stats_(const char *filename, struct stat *stats);
 120 static void set_file_stats_(const char *filename, struct stat *stats);
 121
 122 static FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status);
 123
 124
 125 #ifdef FLAC__VALGRIND_TESTING
 126 static size_t local__fwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream)
 127 {
 128         size_t ret = fwrite(ptr, size, nmemb, stream);
 129         if(!ferror(stream))
 130                 fflush(stream);
 131         return ret;
 132 }
 133 #else
 134 #define local__fwrite fwrite
 135 #endif
 136
 137 /****************************************************************************
 138  *
 139  * Level 0 implementation
 140  *
 141  ***************************************************************************/
 142
 143 static FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__FileDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data);
 144 static void metadata_callback_(const FLAC__FileDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data);
 145 static void error_callback_(const FLAC__FileDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data);
 146
 147 typedef struct {
 148         FLAC__bool got_error;
 149         FLAC__bool got_streaminfo;
 150         FLAC__StreamMetadata *streaminfo;
 151 } level0_client_data;
 152
 153 FLAC_API FLAC__bool FLAC__metadata_get_streaminfo(const char *filename, FLAC__StreamMetadata *streaminfo)
 154 {
 155         level0_client_data cd;
 156         FLAC__FileDecoder *decoder;
 157
 158         FLAC__ASSERT(0 != filename);
 159         FLAC__ASSERT(0 != streaminfo);
 160
 161         decoder = FLAC__file_decoder_new();
 162
 163         if(0 == decoder)
 164                 return false;
 165
 166         cd.got_error = false;
 167         cd.got_streaminfo = false;
 168         cd.streaminfo = streaminfo;
 169
 170         FLAC__file_decoder_set_md5_checking(decoder, false);
 171         FLAC__file_decoder_set_filename(decoder, filename);
 172         FLAC__file_decoder_set_metadata_ignore_all(decoder);
 173         FLAC__file_decoder_set_metadata_respond(decoder, FLAC__METADATA_TYPE_STREAMINFO);
 174         FLAC__file_decoder_set_write_callback(decoder, write_callback_);
 175         FLAC__file_decoder_set_metadata_callback(decoder, metadata_callback_);
 176         FLAC__file_decoder_set_error_callback(decoder, error_callback_);
 177         FLAC__file_decoder_set_client_data(decoder, &cd);
 178
 179         if(FLAC__file_decoder_init(decoder) != FLAC__FILE_DECODER_OK || cd.got_error) {
 180                 FLAC__file_decoder_finish(decoder);
 181                 FLAC__file_decoder_delete(decoder);
 182                 return false;
 183         }
 184
 185         /* the first thing decoded must be the STREAMINFO block: */
 186         if(!FLAC__file_decoder_process_until_end_of_metadata(decoder) || cd.got_error) {
 187                 FLAC__file_decoder_finish(decoder);
 188                 FLAC__file_decoder_delete(decoder);
 189                 return false;
 190         }
 191
 192         FLAC__file_decoder_finish(decoder);
 193         FLAC__file_decoder_delete(decoder);
 194
 195         return !cd.got_error && cd.got_streaminfo;
 196 }
 197
 198 FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__FileDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
 199 {
 200         (void)decoder, (void)frame, (void)buffer, (void)client_data;
 201
 202         return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;
 203 }
 204
 205 void metadata_callback_(const FLAC__FileDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
 206 {
 207         level0_client_data *cd = (level0_client_data *)client_data;
 208         (void)decoder;
 209
 210         if(metadata->type == FLAC__METADATA_TYPE_STREAMINFO && 0 != cd->streaminfo) {
 211                 *(cd->streaminfo) = *metadata;
 212                 cd->got_streaminfo = true;
 213         }
 214 }
 215
 216 void error_callback_(const FLAC__FileDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
 217 {
 218         level0_client_data *cd = (level0_client_data *)client_data;
 219         (void)decoder;
 220
 221         if(status != FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC)
 222                 cd->got_error = true;
 223 }
 224
 225
 226 /****************************************************************************
 227  *
 228  * Level 1 implementation
 229  *
 230  ***************************************************************************/
 231
 232 #define SIMPLE_ITERATOR_MAX_PUSH_DEPTH (1+4)
 233 /* 1 for initial offset, +4 for our own personal use */
 234
 235 struct FLAC__Metadata_SimpleIterator {
 236         FILE *file;
 237         char *filename, *tempfile_path_prefix;
 238         struct stat stats;
 239         FLAC__bool has_stats;
 240         FLAC__bool is_writable;
 241         FLAC__Metadata_SimpleIteratorStatus status;
 242         /*@@@ 2G limits here because of the offset type: */
 243         long offset[SIMPLE_ITERATOR_MAX_PUSH_DEPTH];
 244         long first_offset; /* this is the offset to the STREAMINFO block */
 245         unsigned depth;
 246         /* this is the metadata block header of the current block we are pointing to: */
 247         FLAC__bool is_last;
 248         FLAC__MetadataType type;
 249         unsigned length;
 250 };
 251
 252 FLAC_API const char * const FLAC__Metadata_SimpleIteratorStatusString[] = {
 253         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK",
 254         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT",
 255         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE",
 256         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE",
 257         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE",
 258         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA",
 259         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR",
 260         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR",
 261         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR",
 262         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR",
 263         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR",
 264         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR",
 265         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR"
 266 };
 267
 268
 269 FLAC_API FLAC__Metadata_SimpleIterator *FLAC__metadata_simple_iterator_new()
 270 {
 271         FLAC__Metadata_SimpleIterator *iterator = (FLAC__Metadata_SimpleIterator*)calloc(1, sizeof(FLAC__Metadata_SimpleIterator));
 272
 273         if(0 != iterator) {
 274                 iterator->file = 0;
 275                 iterator->filename = 0;
 276                 iterator->tempfile_path_prefix = 0;
 277                 iterator->has_stats = false;
 278                 iterator->is_writable = false;
 279                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
 280                 iterator->first_offset = iterator->offset[0] = -1;
 281                 iterator->depth = 0;
 282         }
 283
 284         return iterator;
 285 }
 286
 287 static void simple_iterator_free_guts_(FLAC__Metadata_SimpleIterator *iterator)
 288 {
 289         FLAC__ASSERT(0 != iterator);
 290
 291         if(0 != iterator->file) {
 292                 fclose(iterator->file);
 293                 iterator->file = 0;
 294                 if(iterator->has_stats)
 295                         set_file_stats_(iterator->filename, &iterator->stats);
 296         }
 297         if(0 != iterator->filename) {
 298                 free(iterator->filename);
 299                 iterator->filename = 0;
 300         }
 301         if(0 != iterator->tempfile_path_prefix) {
 302                 free(iterator->tempfile_path_prefix);
 303                 iterator->tempfile_path_prefix = 0;
 304         }
 305 }
 306
 307 FLAC_API void FLAC__metadata_simple_iterator_delete(FLAC__Metadata_SimpleIterator *iterator)
 308 {
 309         FLAC__ASSERT(0 != iterator);
 310
 311         simple_iterator_free_guts_(iterator);
 312         free(iterator);
 313 }
 314
 315 FLAC_API FLAC__Metadata_SimpleIteratorStatus FLAC__metadata_simple_iterator_status(FLAC__Metadata_SimpleIterator *iterator)
 316 {
 317         FLAC__Metadata_SimpleIteratorStatus status;
 318
 319         FLAC__ASSERT(0 != iterator);
 320
 321         status = iterator->status;
 322         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
 323         return status;
 324 }
 325
 326 static FLAC__bool simple_iterator_prime_input_(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool read_only)
 327 {
 328         unsigned ret;
 329
 330         FLAC__ASSERT(0 != iterator);
 331
 332         if(read_only || 0 == (iterator->file = fopen(iterator->filename, "r+b"))) {
 333                 iterator->is_writable = false;
 334                 if(read_only || errno == EACCES) {
 335                         if(0 == (iterator->file = fopen(iterator->filename, "rb"))) {
 336                                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
 337                                 return false;
 338                         }
 339                 }
 340                 else {
 341                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
 342                         return false;
 343                 }
 344         }
 345         else {
 346                 iterator->is_writable = true;
 347         }
 348
 349         ret = seek_to_first_metadata_block_(iterator->file);
 350         switch(ret) {
 351                 case 0:
 352                         iterator->depth = 0;
 353                         iterator->first_offset = iterator->offset[iterator->depth] = ftell(iterator->file);
 354                         return read_metadata_block_header_(iterator);
 355                 case 1:
 356                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
 357                         return false;
 358                 case 2:
 359                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE;
 360                         return false;
 361                 default:
 362                         FLAC__ASSERT(0);
 363                         return false;
 364         }
 365 }
 366
 367 #if 0
 368 @@@ If we decide to finish implementing this, put this comment back in metadata.h
 369 /*
 370  * The 'tempfile_path_prefix' allows you to specify a directory where
 371  * tempfiles should go.  Remember that if your metadata edits cause the
 372  * FLAC file to grow, the entire file will have to be rewritten.  If
 373  * 'tempfile_path_prefix' is NULL, the temp file will be written in the
 374  * same directory as the original FLAC file.  This makes replacing the
 375  * original with the tempfile fast but requires extra space in the same
 376  * partition for the tempfile.  If space is a problem, you can pass a
 377  * directory name belonging to a different partition in
 378  * 'tempfile_path_prefix'.  Note that you should use the forward slash
 379  * '/' as the directory separator.  A trailing slash is not needed; it
 380  * will be added automatically.
 381  */
 382 FLAC__bool FLAC__metadata_simple_iterator_init(FLAC__Metadata_SimpleIterator *iterator, const char *filename, FLAC__bool preserve_file_stats, const char *tempfile_path_prefix);
 383 #endif
 384
 385 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)
 386 {
 387         const char *tempfile_path_prefix = 0; /*@@@ search for comments near 'rename(...)' for what it will take to finish implementing this */
 388
 389         FLAC__ASSERT(0 != iterator);
 390         FLAC__ASSERT(0 != filename);
 391
 392         simple_iterator_free_guts_(iterator);
 393
 394         if(!read_only && preserve_file_stats)
 395                 iterator->has_stats = get_file_stats_(filename, &iterator->stats);
 396
 397         if(0 == (iterator->filename = strdup(filename))) {
 398                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 399                 return false;
 400         }
 401         if(0 != tempfile_path_prefix && 0 == (iterator->tempfile_path_prefix = strdup(tempfile_path_prefix))) {
 402                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 403                 return false;
 404         }
 405
 406         return simple_iterator_prime_input_(iterator, read_only);
 407 }
 408
 409 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_is_writable(const FLAC__Metadata_SimpleIterator *iterator)
 410 {
 411         FLAC__ASSERT(0 != iterator);
 412         FLAC__ASSERT(0 != iterator->file);
 413
 414         return iterator->is_writable;
 415 }
 416
 417 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_next(FLAC__Metadata_SimpleIterator *iterator)
 418 {
 419         FLAC__ASSERT(0 != iterator);
 420         FLAC__ASSERT(0 != iterator->file);
 421
 422         if(iterator->is_last)
 423                 return false;
 424
 425         if(0 != fseek(iterator->file, iterator->length, SEEK_CUR)) {
 426                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 427                 return false;
 428         }
 429
 430         iterator->offset[iterator->depth] = ftell(iterator->file);
 431
 432         return read_metadata_block_header_(iterator);
 433 }
 434
 435 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_prev(FLAC__Metadata_SimpleIterator *iterator)
 436 {
 437         long this_offset;
 438
 439         FLAC__ASSERT(0 != iterator);
 440         FLAC__ASSERT(0 != iterator->file);
 441
 442         if(iterator->offset[iterator->depth] == iterator->first_offset)
 443                 return false;
 444
 445         if(0 != fseek(iterator->file, iterator->first_offset, SEEK_SET)) {
 446                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 447                 return false;
 448         }
 449         this_offset = iterator->first_offset;
 450         if(!read_metadata_block_header_(iterator))
 451                 return false;
 452
 453         /* we ignore any error from ftell() and catch it in fseek() */
 454         while(ftell(iterator->file) + (long)iterator->length < iterator->offset[iterator->depth]) {
 455                 if(0 != fseek(iterator->file, iterator->length, SEEK_CUR)) {
 456                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 457                         return false;
 458                 }
 459                 this_offset = ftell(iterator->file);
 460                 if(!read_metadata_block_header_(iterator))
 461                         return false;
 462         }
 463
 464         iterator->offset[iterator->depth] = this_offset;
 465
 466         return true;
 467 }
 468
 469 FLAC_API FLAC__MetadataType FLAC__metadata_simple_iterator_get_block_type(const FLAC__Metadata_SimpleIterator *iterator)
 470 {
 471         FLAC__ASSERT(0 != iterator);
 472         FLAC__ASSERT(0 != iterator->file);
 473
 474         return iterator->type;
 475 }
 476
 477 FLAC_API FLAC__StreamMetadata *FLAC__metadata_simple_iterator_get_block(FLAC__Metadata_SimpleIterator *iterator)
 478 {
 479         FLAC__StreamMetadata *block = FLAC__metadata_object_new(iterator->type);
 480
 481         FLAC__ASSERT(0 != iterator);
 482         FLAC__ASSERT(0 != iterator->file);
 483
 484         if(0 != block) {
 485                 block->is_last = iterator->is_last;
 486                 block->length = iterator->length;
 487
 488                 if(!read_metadata_block_data_(iterator, block)) {
 489                         FLAC__metadata_object_delete(block);
 490                         return 0;
 491                 }
 492
 493                 /* back up to the beginning of the block data to stay consistent */
 494                 if(0 != fseek(iterator->file, iterator->offset[iterator->depth] + FLAC__STREAM_METADATA_HEADER_LENGTH, SEEK_SET)) {
 495                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 496                         FLAC__metadata_object_delete(block);
 497                         return 0;
 498                 }
 499         }
 500         else
 501                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 502
 503         return block;
 504 }
 505
 506 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_set_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding)
 507 {
 508         FLAC__ASSERT_DECLARATION(long debug_target_offset = iterator->offset[iterator->depth];)
 509         FLAC__bool ret;
 510
 511         FLAC__ASSERT(0 != iterator);
 512         FLAC__ASSERT(0 != iterator->file);
 513         FLAC__ASSERT(0 != block);
 514
 515         if(!iterator->is_writable) {
 516                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE;
 517                 return false;
 518         }
 519
 520         if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO || block->type == FLAC__METADATA_TYPE_STREAMINFO) {
 521                 if(iterator->type != block->type) {
 522                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 523                         return false;
 524                 }
 525         }
 526
 527         block->is_last = iterator->is_last;
 528
 529         if(iterator->length == block->length)
 530                 return write_metadata_block_stationary_(iterator, block);
 531         else if(iterator->length > block->length) {
 532                 if(use_padding && iterator->length >= FLAC__STREAM_METADATA_HEADER_LENGTH + block->length) {
 533                         ret = write_metadata_block_stationary_with_padding_(iterator, block, iterator->length - FLAC__STREAM_METADATA_HEADER_LENGTH - block->length, block->is_last);
 534                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 535                         FLAC__ASSERT(!ret || ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 536                         return ret;
 537                 }
 538                 else {
 539                         ret = rewrite_whole_file_(iterator, block, /*append=*/false);
 540                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 541                         FLAC__ASSERT(!ret || ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 542                         return ret;
 543                 }
 544         }
 545         else /* iterator->length < block->length */ {
 546                 unsigned padding_leftover = 0;
 547                 FLAC__bool padding_is_last = false;
 548                 if(use_padding) {
 549                         /* first see if we can even use padding */
 550                         if(iterator->is_last) {
 551                                 use_padding = false;
 552                         }
 553                         else {
 554                                 const unsigned extra_padding_bytes_required = block->length - iterator->length;
 555                                 simple_iterator_push_(iterator);
 556                                 if(!FLAC__metadata_simple_iterator_next(iterator)) {
 557                                         (void)simple_iterator_pop_(iterator);
 558                                         return false;
 559                                 }
 560                                 if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
 561                                         use_padding = false;
 562                                 }
 563                                 else {
 564                                         if(FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length == extra_padding_bytes_required) {
 565                                                 padding_leftover = 0;
 566                                                 block->is_last = iterator->is_last;
 567                                         }
 568                                         else if(iterator->length < extra_padding_bytes_required)
 569                                                 use_padding = false;
 570                                         else {
 571                                                 padding_leftover = FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length - extra_padding_bytes_required;
 572                                                 padding_is_last = iterator->is_last;
 573                                                 block->is_last = false;
 574                                         }
 575                                 }
 576                                 if(!simple_iterator_pop_(iterator))
 577                                         return false;
 578                         }
 579                 }
 580                 if(use_padding) {
 581                         if(padding_leftover == 0) {
 582                                 ret = write_metadata_block_stationary_(iterator, block);
 583                                 FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 584                                 FLAC__ASSERT(!ret || ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 585                                 return ret;
 586                         }
 587                         else {
 588                                 FLAC__ASSERT(padding_leftover >= FLAC__STREAM_METADATA_HEADER_LENGTH);
 589                                 ret = write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover - FLAC__STREAM_METADATA_HEADER_LENGTH, padding_is_last);
 590                                 FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 591                                 FLAC__ASSERT(!ret || ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 592                                 return ret;
 593                         }
 594                 }
 595                 else {
 596                         ret = rewrite_whole_file_(iterator, block, /*append=*/false);
 597                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 598                         FLAC__ASSERT(!ret || ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 599                         return ret;
 600                 }
 601         }
 602 }
 603
 604 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_insert_block_after(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding)
 605 {
 606         unsigned padding_leftover = 0;
 607         FLAC__bool padding_is_last = false;
 608
 609         FLAC__ASSERT_DECLARATION(long debug_target_offset = iterator->offset[iterator->depth] + FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length;)
 610         FLAC__bool ret;
 611
 612         FLAC__ASSERT(0 != iterator);
 613         FLAC__ASSERT(0 != iterator->file);
 614         FLAC__ASSERT(0 != block);
 615
 616         if(!iterator->is_writable)
 617                 return false;
 618
 619         if(block->type == FLAC__METADATA_TYPE_STREAMINFO) {
 620                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 621                 return false;
 622         }
 623
 624         block->is_last = iterator->is_last;
 625
 626         if(use_padding) {
 627                 /* first see if we can even use padding */
 628                 if(iterator->is_last) {
 629                         use_padding = false;
 630                 }
 631                 else {
 632                         simple_iterator_push_(iterator);
 633                         if(!FLAC__metadata_simple_iterator_next(iterator)) {
 634                                 (void)simple_iterator_pop_(iterator);
 635                                 return false;
 636                         }
 637                         if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
 638                                 use_padding = false;
 639                         }
 640                         else {
 641                                 if(iterator->length == block->length) {
 642                                         padding_leftover = 0;
 643                                         block->is_last = iterator->is_last;
 644                                 }
 645                                 else if(iterator->length < FLAC__STREAM_METADATA_HEADER_LENGTH + block->length)
 646                                         use_padding = false;
 647                                 else {
 648                                         padding_leftover = iterator->length - block->length;
 649                                         padding_is_last = iterator->is_last;
 650                                         block->is_last = false;
 651                                 }
 652                         }
 653                         if(!simple_iterator_pop_(iterator))
 654                                 return false;
 655                 }
 656         }
 657         if(use_padding) {
 658                 /* move to the next block, which is suitable padding */
 659                 if(!FLAC__metadata_simple_iterator_next(iterator))
 660                         return false;
 661                 if(padding_leftover == 0) {
 662                         ret = write_metadata_block_stationary_(iterator, block);
 663                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 664                         FLAC__ASSERT(ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 665                         return ret;
 666                 }
 667                 else {
 668                         FLAC__ASSERT(padding_leftover >= FLAC__STREAM_METADATA_HEADER_LENGTH);
 669                         ret = write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover - FLAC__STREAM_METADATA_HEADER_LENGTH, padding_is_last);
 670                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 671                         FLAC__ASSERT(ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 672                         return ret;
 673                 }
 674         }
 675         else {
 676                 ret = rewrite_whole_file_(iterator, block, /*append=*/true);
 677                 FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 678                 FLAC__ASSERT(ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 679                 return ret;
 680         }
 681 }
 682
 683 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_delete_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool use_padding)
 684 {
 685         FLAC__ASSERT_DECLARATION(long debug_target_offset = iterator->offset[iterator->depth];)
 686         FLAC__bool ret;
 687
 688         if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO) {
 689                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 690                 return false;
 691         }
 692
 693         if(use_padding) {
 694                 FLAC__StreamMetadata *padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING);
 695                 if(0 == padding) {
 696                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 697                         return false;
 698                 }
 699                 padding->length = iterator->length;
 700                 if(!FLAC__metadata_simple_iterator_set_block(iterator, padding, false)) {
 701                         FLAC__metadata_object_delete(padding);
 702                         return false;
 703                 }
 704                 FLAC__metadata_object_delete(padding);
 705                 if(!FLAC__metadata_simple_iterator_prev(iterator))
 706                         return false;
 707                 FLAC__ASSERT(iterator->offset[iterator->depth] + (long)FLAC__STREAM_METADATA_HEADER_LENGTH + (long)iterator->length == debug_target_offset);
 708                 FLAC__ASSERT(ftell(iterator->file) + (long)iterator->length == debug_target_offset);
 709                 return true;
 710         }
 711         else {
 712                 ret = rewrite_whole_file_(iterator, 0, /*append=*/false);
 713                 FLAC__ASSERT(iterator->offset[iterator->depth] + (long)FLAC__STREAM_METADATA_HEADER_LENGTH + (long)iterator->length == debug_target_offset);
 714                 FLAC__ASSERT(ftell(iterator->file) + (long)iterator->length == debug_target_offset);
 715                 return ret;
 716         }
 717 }
 718
 719
 720
 721 /****************************************************************************
 722  *
 723  * Level 2 implementation
 724  *
 725  ***************************************************************************/
 726
 727
 728 typedef struct FLAC__Metadata_Node {
 729         FLAC__StreamMetadata *data;
 730         struct FLAC__Metadata_Node *prev, *next;
 731 } FLAC__Metadata_Node;
 732
 733 struct FLAC__Metadata_Chain {
 734         char *filename;
 735         FLAC__Metadata_Node *head;
 736         FLAC__Metadata_Node *tail;
 737         unsigned nodes;
 738         FLAC__Metadata_ChainStatus status;
 739         long first_offset, last_offset; /*@@@ 2G limit */
 740         /*
 741          * This is the length of the chain initially read from the FLAC file.
 742          * it is used to compare against the current length to decide whether
 743          * or not the whole file has to be rewritten.
 744          */
 745         unsigned initial_length; /*@@@ 4G limit */
 746 };
 747
 748 struct FLAC__Metadata_Iterator {
 749         FLAC__Metadata_Chain *chain;
 750         FLAC__Metadata_Node *current;
 751 };
 752
 753 FLAC_API const char * const FLAC__Metadata_ChainStatusString[] = {
 754         "FLAC__METADATA_CHAIN_STATUS_OK",
 755         "FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT",
 756         "FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE",
 757         "FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE",
 758         "FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE",
 759         "FLAC__METADATA_CHAIN_STATUS_BAD_METADATA",
 760         "FLAC__METADATA_CHAIN_STATUS_READ_ERROR",
 761         "FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR",
 762         "FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR",
 763         "FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR",
 764         "FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR",
 765         "FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR",
 766         "FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR"
 767 };
 768
 769
 770 static FLAC__Metadata_Node *node_new_()
 771 {
 772         return (FLAC__Metadata_Node*)calloc(1, sizeof(FLAC__Metadata_Node));
 773 }
 774
 775 static void node_delete_(FLAC__Metadata_Node *node)
 776 {
 777         FLAC__ASSERT(0 != node);
 778         if(0 != node->data)
 779                 FLAC__metadata_object_delete(node->data);
 780         free(node);
 781 }
 782
 783 static void chain_append_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 784 {
 785         FLAC__ASSERT(0 != chain);
 786         FLAC__ASSERT(0 != node);
 787         FLAC__ASSERT(0 != node->data);
 788
 789         node->next = node->prev = 0;
 790         node->data->is_last = true;
 791         if(0 != chain->tail)
 792                 chain->tail->data->is_last = false;
 793
 794         if(0 == chain->head)
 795                 chain->head = node;
 796         else {
 797                 FLAC__ASSERT(0 != chain->tail);
 798                 chain->tail->next = node;
 799                 node->prev = chain->tail;
 800         }
 801         chain->tail = node;
 802         chain->nodes++;
 803 }
 804
 805 static void chain_remove_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 806 {
 807         FLAC__ASSERT(0 != chain);
 808         FLAC__ASSERT(0 != node);
 809
 810         if(node == chain->head)
 811                 chain->head = node->next;
 812         else
 813                 node->prev->next = node->next;
 814
 815         if(node == chain->tail)
 816                 chain->tail = node->prev;
 817         else
 818                 node->next->prev = node->prev;
 819
 820         if(0 != chain->tail)
 821                 chain->tail->data->is_last = true;
 822
 823         chain->nodes--;
 824 }
 825
 826 static void chain_delete_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 827 {
 828         chain_remove_node_(chain, node);
 829         node_delete_(node);
 830 }
 831
 832 static unsigned chain_calculate_length_(FLAC__Metadata_Chain *chain)
 833 {
 834         const FLAC__Metadata_Node *node;
 835         unsigned length = 0;
 836         for(node = chain->head; node; node = node->next)
 837                 length += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
 838         return length;
 839 }
 840
 841 static void iterator_insert_node_(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Node *node)
 842 {
 843         FLAC__ASSERT(0 != node);
 844         FLAC__ASSERT(0 != node->data);
 845         FLAC__ASSERT(0 != iterator);
 846         FLAC__ASSERT(0 != iterator->current);
 847         FLAC__ASSERT(0 != iterator->chain);
 848         FLAC__ASSERT(0 != iterator->chain->head);
 849         FLAC__ASSERT(0 != iterator->chain->tail);
 850
 851         node->data->is_last = false;
 852
 853         node->prev = iterator->current->prev;
 854         node->next = iterator->current;
 855
 856         if(0 == node->prev)
 857                 iterator->chain->head = node;
 858         else
 859                 node->prev->next = node;
 860
 861         iterator->current->prev = node;
 862
 863         iterator->chain->nodes++;
 864 }
 865
 866 static void iterator_insert_node_after_(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Node *node)
 867 {
 868         FLAC__ASSERT(0 != node);
 869         FLAC__ASSERT(0 != node->data);
 870         FLAC__ASSERT(0 != iterator);
 871         FLAC__ASSERT(0 != iterator->current);
 872         FLAC__ASSERT(0 != iterator->chain);
 873         FLAC__ASSERT(0 != iterator->chain->head);
 874         FLAC__ASSERT(0 != iterator->chain->tail);
 875
 876         iterator->current->data->is_last = false;
 877
 878         node->prev = iterator->current;
 879         node->next = iterator->current->next;
 880
 881         if(0 == node->next)
 882                 iterator->chain->tail = node;
 883         else
 884                 node->next->prev = node;
 885
 886         node->prev->next = node;
 887
 888         iterator->chain->tail->data->is_last = true;
 889
 890         iterator->chain->nodes++;
 891 }
 892
 893 /* return true iff node and node->next are both padding */
 894 static FLAC__bool chain_merge_adjacent_padding_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 895 {
 896         if(node->data->type == FLAC__METADATA_TYPE_PADDING && 0 != node->next && node->next->data->type == FLAC__METADATA_TYPE_PADDING) {
 897                 const unsigned growth = FLAC__STREAM_METADATA_HEADER_LENGTH + node->next->data->length;
 898                 node->data->length += growth;
 899
 900                 chain_delete_node_(chain, node->next);
 901                 return true;
 902         }
 903         else
 904                 return false;
 905 }
 906
 907 FLAC_API FLAC__Metadata_Chain *FLAC__metadata_chain_new()
 908 {
 909         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)calloc(1, sizeof(FLAC__Metadata_Chain));
 910
 911         if(0 != chain) {
 912                 chain->filename = 0;
 913                 chain->head = chain->tail = 0;
 914                 chain->nodes = 0;
 915                 chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
 916                 chain->initial_length = 0;
 917         }
 918
 919         return chain;
 920 }
 921
 922 FLAC_API void FLAC__metadata_chain_delete(FLAC__Metadata_Chain *chain)
 923 {
 924         FLAC__Metadata_Node *node, *next;
 925
 926         FLAC__ASSERT(0 != chain);
 927
 928         for(node = chain->head; node; ) {
 929                 next = node->next;
 930                 node_delete_(node);
 931                 node = next;
 932         }
 933
 934         if(0 != chain->filename)
 935                 free(chain->filename);
 936
 937         free(chain);
 938 }
 939
 940 FLAC_API FLAC__Metadata_ChainStatus FLAC__metadata_chain_status(FLAC__Metadata_Chain *chain)
 941 {
 942         FLAC__Metadata_ChainStatus status;
 943
 944         FLAC__ASSERT(0 != chain);
 945
 946         status = chain->status;
 947         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
 948         return status;
 949 }
 950
 951 FLAC_API FLAC__bool FLAC__metadata_chain_read(FLAC__Metadata_Chain *chain, const char *filename)
 952 {
 953         FLAC__Metadata_SimpleIterator *iterator;
 954         FLAC__Metadata_Node *node;
 955
 956         FLAC__ASSERT(0 != chain);
 957         FLAC__ASSERT(0 != filename);
 958
 959         if(0 == (chain->filename = strdup(filename))) {
 960                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
 961                 return false;
 962         }
 963
 964         if(0 == (iterator = FLAC__metadata_simple_iterator_new())) {
 965                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
 966                 return false;
 967         }
 968
 969         if(!FLAC__metadata_simple_iterator_init(iterator, filename, /*read_only=*/true, /*preserve_file_stats=*/false)) {
 970                 chain->status = get_equivalent_status_(iterator->status);
 971                 return false;
 972         }
 973
 974         chain->first_offset = iterator->offset[iterator->depth];
 975
 976         do {
 977                 node = node_new_();
 978                 if(0 == node) {
 979                         chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
 980                         return false;
 981                 }
 982                 node->data = FLAC__metadata_simple_iterator_get_block(iterator);
 983                 if(0 == node->data) {
 984                         node_delete_(node);
 985                         chain->status = get_equivalent_status_(iterator->status);
 986                         return false;
 987                 }
 988                 chain_append_node_(chain, node);
 989         } while(FLAC__metadata_simple_iterator_next(iterator));
 990
 991         if(!iterator->is_last || iterator->status != FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK) {
 992                 chain->status = get_equivalent_status_(iterator->status);
 993                 return false;
 994         }
 995
 996         chain->last_offset = ftell(iterator->file) + iterator->length;
 997         FLAC__metadata_simple_iterator_delete(iterator);
 998
 999         chain->initial_length = chain_calculate_length_(chain);
1000         return true;
1001 }
1002
1003 FLAC_API FLAC__bool FLAC__metadata_chain_write(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__bool preserve_file_stats)
1004 {
1005         struct stat stats;
1006         const char *tempfile_path_prefix = 0;
1007         unsigned current_length;
1008
1009         FLAC__ASSERT(0 != chain);
1010
1011         current_length = chain_calculate_length_(chain);
1012
1013         if(use_padding) {
1014                 if(current_length < chain->initial_length && chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1015                         const unsigned delta = chain->initial_length - current_length;
1016                         chain->tail->data->length += delta;
1017                         current_length += delta;
1018                         FLAC__ASSERT(current_length == chain->initial_length);
1019                 }
1020                 else if(current_length + FLAC__STREAM_METADATA_HEADER_LENGTH <= chain->initial_length) {
1021                         FLAC__StreamMetadata *padding;
1022                         FLAC__Metadata_Node *node;
1023                         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING))) {
1024                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1025                                 return false;
1026                         }
1027                         padding->length = chain->initial_length - (FLAC__STREAM_METADATA_HEADER_LENGTH + current_length);
1028                         if(0 == (node = node_new_())) {
1029                                 FLAC__metadata_object_delete(padding);
1030                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1031                                 return false;
1032                         }
1033                         node->data = padding;
1034                         chain_append_node_(chain, node);
1035                         current_length = chain_calculate_length_(chain);
1036                         FLAC__ASSERT(current_length == chain->initial_length);
1037                 }
1038                 else if(current_length > chain->initial_length) {
1039                         const unsigned delta = current_length - chain->initial_length;
1040                         if(chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1041                                 if(chain->tail->data->length + FLAC__STREAM_METADATA_HEADER_LENGTH == delta) {
1042                                         chain_delete_node_(chain, chain->tail);
1043                                         current_length = chain_calculate_length_(chain);
1044                                         FLAC__ASSERT(current_length == chain->initial_length);
1045                                 }
1046                                 else if(chain->tail->data->length >= delta) {
1047                                         chain->tail->data->length -= delta;
1048                                         current_length -= delta;
1049                                         FLAC__ASSERT(current_length == chain->initial_length);
1050                                 }
1051                         }
1052                 }
1053         }
1054
1055         if(preserve_file_stats)
1056                 get_file_stats_(chain->filename, &stats);
1057
1058         if(current_length == chain->initial_length) {
1059                 if(!chain_rewrite_chain_(chain))
1060                         return false;
1061         }
1062         else {
1063                 if(!chain_rewrite_file_(chain, tempfile_path_prefix))
1064                         return false;
1065         }
1066
1067         if(preserve_file_stats)
1068                 set_file_stats_(chain->filename, &stats);
1069
1070         /* recompute lengths and offsets if necessary */
1071         if(chain->initial_length != current_length) {
1072                 const FLAC__Metadata_Node *node;
1073                 chain->initial_length = current_length;
1074                 chain->last_offset = chain->first_offset;
1075                 for(node = chain->head; node; node = node->next)
1076                         chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1077         }
1078
1079         return true;
1080 }
1081
1082 FLAC_API void FLAC__metadata_chain_merge_padding(FLAC__Metadata_Chain *chain)
1083 {
1084         FLAC__Metadata_Node *node;
1085
1086         FLAC__ASSERT(0 != chain);
1087
1088         for(node = chain->head; node; ) {
1089                 if(!chain_merge_adjacent_padding_(chain, node))
1090                         node = node->next;
1091         }
1092 }
1093
1094 FLAC_API void FLAC__metadata_chain_sort_padding(FLAC__Metadata_Chain *chain)
1095 {
1096         FLAC__Metadata_Node *node, *save;
1097         unsigned i;
1098
1099         FLAC__ASSERT(0 != chain);
1100
1101         /*
1102          * Don't try and be too smart... this simple algo is good enough for
1103          * the small number of nodes that we deal with.
1104          */
1105         for(i = 0, node = chain->head; i < chain->nodes; i++) {
1106                 if(node->data->type == FLAC__METADATA_TYPE_PADDING) {
1107                         save = node->next;
1108                         chain_remove_node_(chain, node);
1109                         chain_append_node_(chain, node);
1110                         node = save;
1111                 }
1112                 else {
1113                         node = node->next;
1114                 }
1115         }
1116
1117         FLAC__metadata_chain_merge_padding(chain);
1118 }
1119
1120
1121 FLAC_API FLAC__Metadata_Iterator *FLAC__metadata_iterator_new()
1122 {
1123         FLAC__Metadata_Iterator *iterator = (FLAC__Metadata_Iterator*)calloc(1, sizeof(FLAC__Metadata_Iterator));
1124
1125         /* calloc() implies:
1126                 iterator->current = 0;
1127                 iterator->chain = 0;
1128         */
1129
1130         return iterator;
1131 }
1132
1133 FLAC_API void FLAC__metadata_iterator_delete(FLAC__Metadata_Iterator *iterator)
1134 {
1135         FLAC__ASSERT(0 != iterator);
1136
1137         free(iterator);
1138 }
1139
1140 FLAC_API void FLAC__metadata_iterator_init(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Chain *chain)
1141 {
1142         FLAC__ASSERT(0 != iterator);
1143         FLAC__ASSERT(0 != chain);
1144         FLAC__ASSERT(0 != chain->head);
1145
1146         iterator->chain = chain;
1147         iterator->current = chain->head;
1148 }
1149
1150 FLAC_API FLAC__bool FLAC__metadata_iterator_next(FLAC__Metadata_Iterator *iterator)
1151 {
1152         FLAC__ASSERT(0 != iterator);
1153
1154         if(0 == iterator->current || 0 == iterator->current->next)
1155                 return false;
1156
1157         iterator->current = iterator->current->next;
1158         return true;
1159 }
1160
1161 FLAC_API FLAC__bool FLAC__metadata_iterator_prev(FLAC__Metadata_Iterator *iterator)
1162 {
1163         FLAC__ASSERT(0 != iterator);
1164
1165         if(0 == iterator->current || 0 == iterator->current->prev)
1166                 return false;
1167
1168         iterator->current = iterator->current->prev;
1169         return true;
1170 }
1171
1172 FLAC_API FLAC__MetadataType FLAC__metadata_iterator_get_block_type(const FLAC__Metadata_Iterator *iterator)
1173 {
1174         FLAC__ASSERT(0 != iterator);
1175         FLAC__ASSERT(0 != iterator->current);
1176         FLAC__ASSERT(0 != iterator->current->data);
1177
1178         return iterator->current->data->type;
1179 }
1180
1181 FLAC_API FLAC__StreamMetadata *FLAC__metadata_iterator_get_block(FLAC__Metadata_Iterator *iterator)
1182 {
1183         FLAC__ASSERT(0 != iterator);
1184         FLAC__ASSERT(0 != iterator->current);
1185
1186         return iterator->current->data;
1187 }
1188
1189 FLAC_API FLAC__bool FLAC__metadata_iterator_set_block(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1190 {
1191         FLAC__ASSERT(0 != iterator);
1192         FLAC__ASSERT(0 != block);
1193         return FLAC__metadata_iterator_delete_block(iterator, false) && FLAC__metadata_iterator_insert_block_after(iterator, block);
1194 }
1195
1196 FLAC_API FLAC__bool FLAC__metadata_iterator_delete_block(FLAC__Metadata_Iterator *iterator, FLAC__bool replace_with_padding)
1197 {
1198         FLAC__Metadata_Node *save;
1199
1200         FLAC__ASSERT(0 != iterator);
1201         FLAC__ASSERT(0 != iterator->current);
1202
1203         if(0 == iterator->current->prev) {
1204                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1205                 return false;
1206         }
1207
1208         save = iterator->current->prev;
1209
1210         if(replace_with_padding) {
1211                 FLAC__metadata_object_delete_data(iterator->current->data);
1212                 iterator->current->data->type = FLAC__METADATA_TYPE_PADDING;
1213         }
1214         else {
1215                 chain_delete_node_(iterator->chain, iterator->current);
1216         }
1217
1218         iterator->current = save;
1219         return true;
1220 }
1221
1222 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_before(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1223 {
1224         FLAC__Metadata_Node *node;
1225
1226         FLAC__ASSERT(0 != iterator);
1227         FLAC__ASSERT(0 != iterator->current);
1228         FLAC__ASSERT(0 != block);
1229
1230         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1231                 return false;
1232
1233         if(0 == iterator->current->prev) {
1234                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1235                 return false;
1236         }
1237
1238         if(0 == (node = node_new_()))
1239                 return false;
1240
1241         node->data = block;
1242         iterator_insert_node_(iterator, node);
1243         iterator->current = node;
1244         return true;
1245 }
1246
1247 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_after(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1248 {
1249         FLAC__Metadata_Node *node;
1250
1251         FLAC__ASSERT(0 != iterator);
1252         FLAC__ASSERT(0 != iterator->current);
1253         FLAC__ASSERT(0 != block);
1254
1255         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1256                 return false;
1257
1258         if(0 == (node = node_new_()))
1259                 return false;
1260
1261         node->data = block;
1262         iterator_insert_node_after_(iterator, node);
1263         iterator->current = node;
1264         return true;
1265 }
1266
1267
1268 /****************************************************************************
1269  *
1270  * Local function definitions
1271  *
1272  ***************************************************************************/
1273
1274 void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
1275 {
1276         unsigned i;
1277
1278         b += bytes;
1279
1280         for(i = 0; i < bytes; i++) {
1281                 *(--b) = (FLAC__byte)(val & 0xff);
1282                 val >>= 8;
1283         }
1284 }
1285
1286 void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
1287 {
1288         unsigned i;
1289
1290         for(i = 0; i < bytes; i++) {
1291                 *(b++) = (FLAC__byte)(val & 0xff);
1292                 val >>= 8;
1293         }
1294 }
1295
1296 void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes)
1297 {
1298         unsigned i;
1299
1300         b += bytes;
1301
1302         for(i = 0; i < bytes; i++) {
1303                 *(--b) = (FLAC__byte)(val & 0xff);
1304                 val >>= 8;
1305         }
1306 }
1307
1308 FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes)
1309 {
1310         FLAC__uint32 ret = 0;
1311         unsigned i;
1312
1313         for(i = 0; i < bytes; i++)
1314                 ret = (ret << 8) | (FLAC__uint32)(*b++);
1315
1316         return ret;
1317 }
1318
1319 FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes)
1320 {
1321         FLAC__uint32 ret = 0;
1322         unsigned i;
1323
1324         b += bytes;
1325
1326         for(i = 0; i < bytes; i++)
1327                 ret = (ret << 8) | (FLAC__uint32)(*--b);
1328
1329         return ret;
1330 }
1331
1332 FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes)
1333 {
1334         FLAC__uint64 ret = 0;
1335         unsigned i;
1336
1337         for(i = 0; i < bytes; i++)
1338                 ret = (ret << 8) | (FLAC__uint64)(*b++);
1339
1340         return ret;
1341 }
1342
1343 FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator)
1344 {
1345         FLAC__byte raw_header[FLAC__STREAM_METADATA_HEADER_LENGTH];
1346
1347         FLAC__ASSERT(0 != iterator);
1348         FLAC__ASSERT(0 != iterator->file);
1349
1350         if(fread(raw_header, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, iterator->file) != FLAC__STREAM_METADATA_HEADER_LENGTH) {
1351                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1352                 return false;
1353         }
1354
1355         iterator->is_last = raw_header[0] & 0x80? true : false;
1356         iterator->type = (FLAC__MetadataType)(raw_header[0] & 0x7f);
1357         iterator->length = unpack_uint32_(raw_header + 1, 3);
1358
1359         /* Note that we don't check:
1360          *    if(iterator->type >= FLAC__METADATA_TYPE_UNDEFINED)
1361          * we just will read in an opaque block
1362          */
1363
1364         return true;
1365 }
1366
1367 FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block)
1368 {
1369         FLAC__ASSERT(0 != iterator);
1370         FLAC__ASSERT(0 != iterator->file);
1371
1372         switch(block->type) {
1373                 case FLAC__METADATA_TYPE_STREAMINFO:
1374                         iterator->status = read_metadata_block_data_streaminfo_(iterator->file, &block->data.stream_info);
1375                         break;
1376                 case FLAC__METADATA_TYPE_PADDING:
1377                         iterator->status = read_metadata_block_data_padding_(iterator->file, &block->data.padding, block->length);
1378                         break;
1379                 case FLAC__METADATA_TYPE_APPLICATION:
1380                         iterator->status = read_metadata_block_data_application_(iterator->file, &block->data.application, block->length);
1381                         break;
1382                 case FLAC__METADATA_TYPE_SEEKTABLE:
1383                         iterator->status = read_metadata_block_data_seektable_(iterator->file, &block->data.seek_table, block->length);
1384                         break;
1385                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
1386                         iterator->status = read_metadata_block_data_vorbis_comment_(iterator->file, &block->data.vorbis_comment);
1387                         break;
1388                 case FLAC__METADATA_TYPE_CUESHEET:
1389                         iterator->status = read_metadata_block_data_cuesheet_(iterator->file, &block->data.cue_sheet);
1390                         break;
1391                 default:
1392                         iterator->status = read_metadata_block_data_unknown_(iterator->file, &block->data.unknown, block->length);
1393                         break;
1394         }
1395
1396         return (iterator->status == FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK);
1397 }
1398
1399 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_(FILE *file, FLAC__StreamMetadata_StreamInfo *block)
1400 {
1401         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH], *b;
1402
1403         FLAC__ASSERT(0 != file);
1404
1405         if(fread(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, file) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
1406                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1407
1408         b = buffer;
1409
1410         /* we are using hardcoded numbers for simplicity but we should
1411          * probably eventually write a bit-level unpacker and use the
1412          * _STREAMINFO_ constants.
1413          */
1414         block->min_blocksize = unpack_uint32_(b, 2); b += 2;
1415         block->max_blocksize = unpack_uint32_(b, 2); b += 2;
1416         block->min_framesize = unpack_uint32_(b, 3); b += 3;
1417         block->max_framesize = unpack_uint32_(b, 3); b += 3;
1418         block->sample_rate = (unpack_uint32_(b, 2) << 4) | ((unsigned)(b[2] & 0xf0) >> 4);
1419         block->channels = (unsigned)((b[2] & 0x0e) >> 1) + 1;
1420         block->bits_per_sample = ((((unsigned)(b[2] & 0x01)) << 4) | (((unsigned)(b[3] & 0xf0)) >> 4)) + 1;
1421         block->total_samples = (((FLAC__uint64)(b[3] & 0x0f)) << 32) | unpack_uint64_(b+4, 4);
1422         memcpy(block->md5sum, b+8, 16);
1423
1424         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1425 }
1426
1427
1428 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_padding_(FILE *file, FLAC__StreamMetadata_Padding *block, unsigned block_length)
1429 {
1430         FLAC__ASSERT(0 != file);
1431
1432         (void)block; /* nothing to do; we don't care about reading the padding bytes */
1433
1434         if(0 != fseek(file, block_length, SEEK_CUR))
1435                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
1436
1437         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1438 }
1439
1440 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_application_(FILE *file, FLAC__StreamMetadata_Application *block, unsigned block_length)
1441 {
1442         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
1443
1444         FLAC__ASSERT(0 != file);
1445
1446         if(fread(block->id, 1, id_bytes, file) != id_bytes)
1447                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1448
1449         block_length -= id_bytes;
1450
1451         if(block_length == 0) {
1452                 block->data = 0;
1453         }
1454         else {
1455                 if(0 == (block->data = (FLAC__byte*)malloc(block_length)))
1456                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
1457
1458                 if(fread(block->data, 1, block_length, file) != block_length)
1459                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1460         }
1461
1462         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1463 }
1464
1465 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_seektable_(FILE *file, FLAC__StreamMetadata_SeekTable *block, unsigned block_length)
1466 {
1467         unsigned i;
1468         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
1469
1470         FLAC__ASSERT(0 != file);
1471         FLAC__ASSERT(block_length % FLAC__STREAM_METADATA_SEEKPOINT_LENGTH == 0);
1472
1473         block->num_points = block_length / FLAC__STREAM_METADATA_SEEKPOINT_LENGTH;
1474
1475         if(block->num_points == 0)
1476                 block->points = 0;
1477         else if(0 == (block->points = (FLAC__StreamMetadata_SeekPoint*)malloc(block->num_points * sizeof(FLAC__StreamMetadata_SeekPoint))))
1478                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
1479
1480         for(i = 0; i < block->num_points; i++) {
1481                 if(fread(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, file) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
1482                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1483                 /* some MAGIC NUMBERs here */
1484                 block->points[i].sample_number = unpack_uint64_(buffer, 8);
1485                 block->points[i].stream_offset = unpack_uint64_(buffer+8, 8);
1486                 block->points[i].frame_samples = unpack_uint32_(buffer+16, 2);
1487         }
1488
1489         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1490 }
1491
1492 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_entry_(FILE *file, FLAC__StreamMetadata_VorbisComment_Entry *entry)
1493 {
1494         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
1495         FLAC__byte buffer[4]; /* magic number is asserted below */
1496
1497         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8 == 4);
1498         FLAC__ASSERT(0 != file);
1499
1500         if(fread(buffer, 1, entry_length_len, file) != entry_length_len)
1501                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1502         entry->length = unpack_uint32_little_endian_(buffer, entry_length_len);
1503
1504         if(0 != entry->entry)
1505                 free(entry->entry);
1506
1507         if(entry->length == 0) {
1508                 entry->entry = 0;
1509         }
1510         else {
1511                 if(0 == (entry->entry = (FLAC__byte*)malloc(entry->length)))
1512                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
1513
1514                 if(fread(entry->entry, 1, entry->length, file) != entry->length)
1515                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1516         }
1517
1518         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1519 }
1520
1521 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_(FILE *file, FLAC__StreamMetadata_VorbisComment *block)
1522 {
1523         unsigned i;
1524         FLAC__Metadata_SimpleIteratorStatus status;
1525         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
1526         FLAC__byte buffer[4]; /* magic number is asserted below */
1527
1528         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8 == 4);
1529         FLAC__ASSERT(0 != file);
1530
1531         if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_(file, &(block->vendor_string))))
1532                 return status;
1533
1534         if(fread(buffer, 1, num_comments_len, file) != num_comments_len)
1535                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1536         block->num_comments = unpack_uint32_little_endian_(buffer, num_comments_len);
1537
1538         if(block->num_comments == 0) {
1539                 block->comments = 0;
1540         }
1541         else if(0 == (block->comments = (FLAC__StreamMetadata_VorbisComment_Entry*)calloc(block->num_comments, sizeof(FLAC__StreamMetadata_VorbisComment_Entry))))
1542                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
1543
1544         for(i = 0; i < block->num_comments; i++) {
1545                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_(file, block->comments + i)))
1546                         return status;
1547         }
1548
1549         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1550 }
1551
1552 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_(FILE *file, FLAC__StreamMetadata_CueSheet_Track *track)
1553 {
1554         unsigned i, len;
1555         FLAC__byte buffer[32]; /* asserted below that this is big enough */
1556
1557         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
1558         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
1559         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);
1560
1561         FLAC__ASSERT(0 != file);
1562
1563         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
1564         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
1565         if(fread(buffer, 1, len, file) != len)
1566                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1567         track->offset = unpack_uint64_(buffer, len);
1568
1569         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
1570         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
1571         if(fread(buffer, 1, len, file) != len)
1572                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1573         track->number = (FLAC__byte)unpack_uint32_(buffer, len);
1574
1575         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
1576         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
1577         if(fread(track->isrc, 1, len, file) != len)
1578                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1579
1580         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);
1581         len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
1582         if(fread(buffer, 1, len, file) != len)
1583                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1584         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN == 1);
1585         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN == 1);
1586         track->type = buffer[0] >> 7;
1587         track->pre_emphasis = (buffer[0] >> 6) & 1;
1588
1589         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
1590         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
1591         if(fread(buffer, 1, len, file) != len)
1592                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1593         track->num_indices = (FLAC__byte)unpack_uint32_(buffer, len);
1594
1595         if(track->num_indices == 0) {
1596                 track->indices = 0;
1597         }
1598         else if(0 == (track->indices = (FLAC__StreamMetadata_CueSheet_Index*)calloc(track->num_indices, sizeof(FLAC__StreamMetadata_CueSheet_Index))))
1599                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
1600
1601         for(i = 0; i < track->num_indices; i++) {
1602                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
1603                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
1604                 if(fread(buffer, 1, len, file) != len)
1605                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1606                 track->indices[i].offset = unpack_uint64_(buffer, len);
1607
1608                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
1609                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
1610                 if(fread(buffer, 1, len, file) != len)
1611                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1612                 track->indices[i].number = (FLAC__byte)unpack_uint32_(buffer, len);
1613
1614                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
1615                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
1616                 if(fread(buffer, 1, len, file) != len)
1617                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1618         }
1619
1620         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1621 }
1622
1623 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_(FILE *file, FLAC__StreamMetadata_CueSheet *block)
1624 {
1625         unsigned i, len;
1626         FLAC__Metadata_SimpleIteratorStatus status;
1627         FLAC__byte buffer[1024]; /* MSVC needs a constant expression so we put a magic number and assert */
1628
1629         FLAC__ASSERT(0 != file);
1630         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN)/8 <= sizeof(buffer));
1631         FLAC__ASSERT(sizeof(FLAC__uint64) <= sizeof(buffer));
1632
1633         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
1634         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
1635         if(fread(block->media_catalog_number, 1, len, file) != len)
1636                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1637
1638         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
1639         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
1640         if(fread(buffer, 1, len, file) != len)
1641                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1642         block->lead_in = unpack_uint64_(buffer, len);
1643
1644         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
1645         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
1646         if(fread(buffer, 1, len, file) != len)
1647                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1648         block->is_cd = buffer[0]&0x80? true : false;
1649
1650         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
1651         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
1652         if(fread(buffer, 1, len, file) != len)
1653                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1654         block->num_tracks = unpack_uint32_(buffer, len);
1655
1656         if(block->num_tracks == 0) {
1657                 block->tracks = 0;
1658         }
1659         else if(0 == (block->tracks = (FLAC__StreamMetadata_CueSheet_Track*)calloc(block->num_tracks, sizeof(FLAC__StreamMetadata_CueSheet_Track))))
1660                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
1661
1662         for(i = 0; i < block->num_tracks; i++) {
1663                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_cuesheet_track_(file, block->tracks + i)))
1664                         return status;
1665         }
1666
1667         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1668 }
1669
1670 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_unknown_(FILE *file, FLAC__StreamMetadata_Unknown *block, unsigned block_length)
1671 {
1672         FLAC__ASSERT(0 != file);
1673
1674         if(block_length == 0) {
1675                 block->data = 0;
1676         }
1677         else {
1678                 if(0 == (block->data = (FLAC__byte*)malloc(block_length)))
1679                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
1680
1681                 if(fread(block->data, 1, block_length, file) != block_length)
1682                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1683         }
1684
1685         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1686 }
1687
1688 FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
1689 {
1690         FLAC__byte buffer[FLAC__STREAM_METADATA_HEADER_LENGTH];
1691
1692         FLAC__ASSERT(0 != file);
1693         FLAC__ASSERT(0 != status);
1694         FLAC__ASSERT(block->length < (1u << FLAC__STREAM_METADATA_LENGTH_LEN));
1695
1696         buffer[0] = (block->is_last? 0x80 : 0) | (FLAC__byte)block->type;
1697         pack_uint32_(block->length, buffer + 1, 3);
1698
1699         if(local__fwrite(buffer, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, file) != FLAC__STREAM_METADATA_HEADER_LENGTH) {
1700                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1701                 return false;
1702         }
1703
1704         return true;
1705 }
1706
1707 FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
1708 {
1709         FLAC__ASSERT(0 != file);
1710         FLAC__ASSERT(0 != status);
1711
1712         switch(block->type) {
1713                 case FLAC__METADATA_TYPE_STREAMINFO:
1714                         *status = write_metadata_block_data_streaminfo_(file, &block->data.stream_info);
1715                         break;
1716                 case FLAC__METADATA_TYPE_PADDING:
1717                         *status = write_metadata_block_data_padding_(file, &block->data.padding, block->length);
1718                         break;
1719                 case FLAC__METADATA_TYPE_APPLICATION:
1720                         *status = write_metadata_block_data_application_(file, &block->data.application, block->length);
1721                         break;
1722                 case FLAC__METADATA_TYPE_SEEKTABLE:
1723                         *status = write_metadata_block_data_seektable_(file, &block->data.seek_table);
1724                         break;
1725                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
1726                         *status = write_metadata_block_data_vorbis_comment_(file, &block->data.vorbis_comment);
1727                         break;
1728                 case FLAC__METADATA_TYPE_CUESHEET:
1729                         *status = write_metadata_block_data_cuesheet_(file, &block->data.cue_sheet);
1730                         break;
1731                 default:
1732                         *status = write_metadata_block_data_unknown_(file, &block->data.unknown, block->length);
1733                         break;
1734         }
1735         return (*status == FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK);
1736 }
1737
1738 FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_streaminfo_(FILE *file, const FLAC__StreamMetadata_StreamInfo *block)
1739 {
1740         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH];
1741         const unsigned channels1 = block->channels - 1;
1742         const unsigned bps1 = block->bits_per_sample - 1;
1743
1744         FLAC__ASSERT(0 != file);
1745
1746         /* we are using hardcoded numbers for simplicity but we should
1747          * probably eventually write a bit-level packer and use the
1748          * _STREAMINFO_ constants.
1749          */
1750         pack_uint32_(block->min_blocksize, buffer, 2);
1751         pack_uint32_(block->max_blocksize, buffer+2, 2);
1752         pack_uint32_(block->min_framesize, buffer+4, 3);
1753         pack_uint32_(block->max_framesize, buffer+7, 3);
1754         buffer[10] = (block->sample_rate >> 12) & 0xff;
1755         buffer[11] = (block->sample_rate >> 4) & 0xff;
1756         buffer[12] = ((block->sample_rate & 0x0f) << 4) | (channels1 << 1) | (bps1 >> 4);
1757         buffer[13] = (FLAC__byte)(((bps1 & 0x0f) << 4) | ((block->total_samples >> 32) & 0x0f));
1758         pack_uint32_((FLAC__uint32)block->total_samples, buffer+14, 4);
1759         memcpy(buffer+18, block->md5sum, 16);
1760
1761         if(local__fwrite(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, file) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
1762                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1763
1764         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1765 }
1766
1767 FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_padding_(FILE *file, const FLAC__StreamMetadata_Padding *block, unsigned block_length)
1768 {
1769         unsigned i, n = block_length;
1770         FLAC__byte buffer[1024];
1771
1772         FLAC__ASSERT(0 != file);
1773
1774         (void)block;
1775
1776         memset(buffer, 0, 1024);
1777
1778         for(i = 0; i < n/1024; i++)
1779                 if(local__fwrite(buffer, 1, 1024, file) != 1024)
1780                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1781
1782         n %= 1024;
1783
1784         if(local__fwrite(buffer, 1, n, file) != n)
1785                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1786
1787         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1788 }
1789
1790 FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_application_(FILE *file, const FLAC__StreamMetadata_Application *block, unsigned block_length)
1791 {
1792         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
1793
1794         FLAC__ASSERT(0 != file);
1795
1796         if(local__fwrite(block->id, 1, id_bytes, file) != id_bytes)
1797                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1798
1799         block_length -= id_bytes;
1800
1801         if(local__fwrite(block->data, 1, block_length, file) != block_length)
1802                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1803
1804         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1805 }
1806
1807 FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_seektable_(FILE *file, const FLAC__StreamMetadata_SeekTable *block)
1808 {
1809         unsigned i;
1810         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
1811
1812         FLAC__ASSERT(0 != file);
1813
1814         for(i = 0; i < block->num_points; i++) {
1815                 /* some MAGIC NUMBERs here */
1816                 pack_uint64_(block->points[i].sample_number, buffer, 8);
1817                 pack_uint64_(block->points[i].stream_offset, buffer+8, 8);
1818                 pack_uint32_(block->points[i].frame_samples, buffer+16, 2);
1819                 if(local__fwrite(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, file) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
1820                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1821         }
1822
1823         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1824 }
1825
1826 FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_vorbis_comment_(FILE *file, const FLAC__StreamMetadata_VorbisComment *block)
1827 {
1828         unsigned i;
1829         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
1830         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
1831         FLAC__byte buffer[4]; /* magic number is asserted below */
1832
1833         FLAC__ASSERT(max(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN, FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN) / 8 == 4);
1834         FLAC__ASSERT(0 != file);
1835
1836         pack_uint32_little_endian_(block->vendor_string.length, buffer, entry_length_len);
1837         if(local__fwrite(buffer, 1, entry_length_len, file) != entry_length_len)
1838                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1839         if(local__fwrite(block->vendor_string.entry, 1, block->vendor_string.length, file) != block->vendor_string.length)
1840                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1841
1842         pack_uint32_little_endian_(block->num_comments, buffer, num_comments_len);
1843         if(local__fwrite(buffer, 1, num_comments_len, file) != num_comments_len)
1844                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1845
1846         for(i = 0; i < block->num_comments; i++) {
1847                 pack_uint32_little_endian_(block->comments[i].length, buffer, entry_length_len);
1848                 if(local__fwrite(buffer, 1, entry_length_len, file) != entry_length_len)
1849                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1850                 if(local__fwrite(block->comments[i].entry, 1, block->comments[i].length, file) != block->comments[i].length)
1851                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1852         }
1853
1854         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1855 }
1856
1857 FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_cuesheet_(FILE *file, const FLAC__StreamMetadata_CueSheet *block)
1858 {
1859         unsigned i, j, len;
1860         FLAC__byte buffer[1024]; /* asserted below that this is big enough */
1861
1862         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
1863         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN/8);
1864         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);
1865         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
1866
1867         FLAC__ASSERT(0 != file);
1868
1869         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
1870         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
1871         if(local__fwrite(block->media_catalog_number, 1, len, file) != len)
1872                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1873
1874         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
1875         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
1876         pack_uint64_(block->lead_in, buffer, len);
1877         if(local__fwrite(buffer, 1, len, file) != len)
1878                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1879
1880         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
1881         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
1882         memset(buffer, 0, len);
1883         if(block->is_cd)
1884                 buffer[0] |= 0x80;
1885         if(local__fwrite(buffer, 1, len, file) != len)
1886                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1887
1888         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
1889         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
1890         pack_uint32_(block->num_tracks, buffer, len);
1891         if(local__fwrite(buffer, 1, len, file) != len)
1892                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1893
1894         for(i = 0; i < block->num_tracks; i++) {
1895                 FLAC__StreamMetadata_CueSheet_Track *track = block->tracks + i;
1896
1897                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
1898                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
1899                 pack_uint64_(track->offset, buffer, len);
1900                 if(local__fwrite(buffer, 1, len, file) != len)
1901                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1902
1903                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
1904                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
1905                 pack_uint32_(track->number, buffer, len);
1906                 if(local__fwrite(buffer, 1, len, file) != len)
1907                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1908
1909                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
1910                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
1911                 if(local__fwrite(track->isrc, 1, len, file) != len)
1912                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1913
1914                 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);
1915                 len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
1916                 memset(buffer, 0, len);
1917                 buffer[0] = (track->type << 7) | (track->pre_emphasis << 6);
1918                 if(local__fwrite(buffer, 1, len, file) != len)
1919                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1920
1921                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
1922                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
1923                 pack_uint32_(track->num_indices, buffer, len);
1924                 if(local__fwrite(buffer, 1, len, file) != len)
1925                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1926
1927                 for(j = 0; j < track->num_indices; j++) {
1928                         FLAC__StreamMetadata_CueSheet_Index *index = track->indices + j;
1929
1930                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
1931                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
1932                         pack_uint64_(index->offset, buffer, len);
1933                         if(local__fwrite(buffer, 1, len, file) != len)
1934                                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1935
1936                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
1937                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
1938                         pack_uint32_(index->number, buffer, len);
1939                         if(local__fwrite(buffer, 1, len, file) != len)
1940                                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1941
1942                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
1943                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
1944                         memset(buffer, 0, len);
1945                         if(local__fwrite(buffer, 1, len, file) != len)
1946                                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1947                 }
1948         }
1949
1950         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1951 }
1952
1953 FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_unknown_(FILE *file, const FLAC__StreamMetadata_Unknown *block, unsigned block_length)
1954 {
1955         FLAC__ASSERT(0 != file);
1956
1957         if(local__fwrite(block->data, 1, block_length, file) != block_length)
1958                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1959
1960         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1961 }
1962
1963 FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block)
1964 {
1965         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
1966                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
1967                 return false;
1968         }
1969
1970         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
1971                 return false;
1972
1973         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
1974                 return false;
1975
1976         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
1977                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
1978                 return false;
1979         }
1980
1981         return read_metadata_block_header_(iterator);
1982 }
1983
1984 FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last)
1985 {
1986         FLAC__StreamMetadata *padding;
1987
1988         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
1989                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
1990                 return false;
1991         }
1992
1993         block->is_last = false;
1994
1995         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
1996                 return false;
1997
1998         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
1999                 return false;
2000
2001         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING)))
2002                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2003
2004         padding->is_last = padding_is_last;
2005         padding->length = padding_length;
2006
2007         if(!write_metadata_block_header_(iterator->file, &iterator->status, padding)) {
2008                 FLAC__metadata_object_delete(padding);
2009                 return false;
2010         }
2011
2012         if(!write_metadata_block_data_(iterator->file, &iterator->status, padding)) {
2013                 FLAC__metadata_object_delete(padding);
2014                 return false;
2015         }
2016
2017         FLAC__metadata_object_delete(padding);
2018
2019         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2020                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2021                 return false;
2022         }
2023
2024         return read_metadata_block_header_(iterator);
2025 }
2026
2027 FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append)
2028 {
2029         FILE *tempfile;
2030         char *tempfilename;
2031         int fixup_is_last_code = 0; /* 0 => no need to change any is_last flags */
2032         long fixup_is_last_flag_offset = -1;
2033
2034         FLAC__ASSERT(0 != block || append == false);
2035
2036         if(iterator->is_last) {
2037                 if(append) {
2038                         fixup_is_last_code = 1; /* 1 => clear the is_last flag at the following offset */
2039                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2040                 }
2041                 else if(0 == block) {
2042                         simple_iterator_push_(iterator);
2043                         if(!FLAC__metadata_simple_iterator_prev(iterator)) {
2044                                 (void)simple_iterator_pop_(iterator);
2045                                 return false;
2046                         }
2047                         fixup_is_last_code = -1; /* -1 => set the is_last the flag at the following offset */
2048                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2049                         if(!simple_iterator_pop_(iterator))
2050                                 return false;
2051                 }
2052         }
2053
2054         if(!simple_iterator_copy_file_prefix_(iterator, &tempfile, &tempfilename, append))
2055                 return false;
2056
2057         if(0 != block) {
2058                 if(!write_metadata_block_header_(tempfile, &iterator->status, block)) {
2059                         cleanup_tempfile_(&tempfile, &tempfilename);
2060                         return false;
2061                 }
2062
2063                 if(!write_metadata_block_data_(tempfile, &iterator->status, block)) {
2064                         cleanup_tempfile_(&tempfile, &tempfilename);
2065                         return false;
2066                 }
2067         }
2068
2069         if(!simple_iterator_copy_file_postfix_(iterator, &tempfile, &tempfilename, fixup_is_last_code, fixup_is_last_flag_offset, block==0))
2070                 return false;
2071
2072         if(append)
2073                 return FLAC__metadata_simple_iterator_next(iterator);
2074
2075         return true;
2076 }
2077
2078 FLAC__bool chain_rewrite_chain_(FLAC__Metadata_Chain *chain)
2079 {
2080         FILE *f;
2081         FLAC__Metadata_Node *node;
2082         FLAC__Metadata_SimpleIteratorStatus status;
2083
2084         FLAC__ASSERT(0 != chain);
2085         FLAC__ASSERT(0 != chain->filename);
2086         FLAC__ASSERT(0 != chain->head);
2087
2088         if(0 == (f = fopen(chain->filename, "r+b"))) {
2089                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
2090                 return false;
2091         }
2092         if(0 != fseek(f, chain->first_offset, SEEK_SET)) {
2093                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
2094                 return false;
2095         }
2096
2097         for(node = chain->head; node; node = node->next) {
2098                 if(!write_metadata_block_header_(f, &status, node->data)) {
2099                         chain->status = get_equivalent_status_(status);
2100                         return false;
2101                 }
2102                 if(!write_metadata_block_data_(f, &status, node->data)) {
2103                         chain->status = get_equivalent_status_(status);
2104                         return false;
2105                 }
2106         }
2107
2108         /*FLAC__ASSERT(fflush(), ftell() == chain->last_offset);*/
2109
2110         (void)fclose(f);
2111
2112         return true;
2113 }
2114
2115 FLAC__bool chain_rewrite_file_(FLAC__Metadata_Chain *chain, const char *tempfile_path_prefix)
2116 {
2117         FILE *f, *tempfile;
2118         char *tempfilename;
2119         FLAC__Metadata_SimpleIteratorStatus status;
2120         const FLAC__Metadata_Node *node;
2121
2122         FLAC__ASSERT(0 != chain);
2123         FLAC__ASSERT(0 != chain->filename);
2124         FLAC__ASSERT(0 != chain->head);
2125
2126         /* copy the file prefix (data up to first metadata block */
2127         if(0 == (f = fopen(chain->filename, "rb"))) {
2128                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
2129                 return false;
2130         }
2131         if(!open_tempfile_(chain->filename, tempfile_path_prefix, &tempfile, &tempfilename, &status)) {
2132                 chain->status = get_equivalent_status_(status);
2133                 cleanup_tempfile_(&tempfile, &tempfilename);
2134                 return false;
2135         }
2136         if(!copy_n_bytes_from_file_(f, tempfile, chain->first_offset, &status)) {
2137                 chain->status = get_equivalent_status_(status);
2138                 cleanup_tempfile_(&tempfile, &tempfilename);
2139                 return false;
2140         }
2141
2142         /* write the metadata */
2143         for(node = chain->head; node; node = node->next) {
2144                 if(!write_metadata_block_header_(tempfile, &status, node->data)) {
2145                         chain->status = get_equivalent_status_(status);
2146                         return false;
2147                 }
2148                 if(!write_metadata_block_data_(tempfile, &status, node->data)) {
2149                         chain->status = get_equivalent_status_(status);
2150                         return false;
2151                 }
2152         }
2153         /*FLAC__ASSERT(fflush(), ftell() == chain->last_offset);*/
2154
2155         /* copy the file postfix (everything after the metadata) */
2156         if(0 != fseek(f, chain->last_offset, SEEK_SET)) {
2157                 cleanup_tempfile_(&tempfile, &tempfilename);
2158                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
2159                 return false;
2160         }
2161         if(!copy_remaining_bytes_from_file_(f, tempfile, &status)) {
2162                 cleanup_tempfile_(&tempfile, &tempfilename);
2163                 chain->status = get_equivalent_status_(status);
2164                 return false;
2165         }
2166
2167         /* move the tempfile on top of the original */
2168         (void)fclose(f);
2169         if(!transport_tempfile_(chain->filename, &tempfile, &tempfilename, &status))
2170                 return false;
2171
2172         return true;
2173 }
2174
2175 void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator)
2176 {
2177         FLAC__ASSERT(iterator->depth+1 < SIMPLE_ITERATOR_MAX_PUSH_DEPTH);
2178         iterator->offset[iterator->depth+1] = iterator->offset[iterator->depth];
2179         iterator->depth++;
2180 }
2181
2182 FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator)
2183 {
2184         FLAC__ASSERT(iterator->depth > 0);
2185         iterator->depth--;
2186         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2187                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2188                 return false;
2189         }
2190
2191         return read_metadata_block_header_(iterator);
2192 }
2193
2194 unsigned seek_to_first_metadata_block_(FILE *f)
2195 {
2196         FLAC__byte buffer[4];
2197         size_t n;
2198         unsigned i;
2199
2200         FLAC__ASSERT(0 != f);
2201         FLAC__ASSERT(FLAC__STREAM_SYNC_LENGTH == 4);
2202
2203         /* skip any id3v2 tag */
2204         errno = 0;
2205         n = fread(buffer, 1, 4, f);
2206         if(errno)
2207                 return 1;
2208         else
2209         if(n != 4)
2210                 return 2;
2211         else if(0 == memcmp(buffer, "ID3", 3)) {
2212                 unsigned tag_length = 0;
2213
2214                 /* skip to the tag length */
2215                 if(fseek(f, 2, SEEK_CUR) < 0)
2216                         return 1;
2217
2218                 /* read the length */
2219                 for(i = 0; i < 4; i++) {
2220                         if(fread(buffer, 1, 1, f) < 1 || buffer[0] & 0x80)
2221                                 return 1;
2222                         tag_length <<= 7;
2223                         tag_length |= (buffer[0] & 0x7f);
2224                 }
2225
2226                 /* skip the rest of the tag */
2227                 if(fseek(f, tag_length, SEEK_CUR) < 0)
2228                         return 1;
2229
2230                 /* read the stream sync code */
2231                 errno = 0;
2232                 n = fread(buffer, 1, 4, f);
2233                 if(errno)
2234                         return 1;
2235                 else
2236                 if(n != 4)
2237                         return 2;
2238         }
2239
2240         /* check for the fLaC signature */
2241         if(0 == memcmp(FLAC__STREAM_SYNC_STRING, buffer, FLAC__STREAM_SYNC_LENGTH))
2242                 return 0;
2243         else
2244                 return 2;
2245 }
2246
2247 FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append)
2248 {
2249         const long offset_end = append? iterator->offset[iterator->depth] + (long)FLAC__STREAM_METADATA_HEADER_LENGTH + (long)iterator->length : iterator->offset[iterator->depth];
2250
2251         if(0 != fseek(iterator->file, 0, SEEK_SET)) {
2252                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2253                 return false;
2254         }
2255         if(!open_tempfile_(iterator->filename, iterator->tempfile_path_prefix, tempfile, tempfilename, &iterator->status)) {
2256                 cleanup_tempfile_(tempfile, tempfilename);
2257                 return false;
2258         }
2259         if(!copy_n_bytes_from_file_(iterator->file, *tempfile, offset_end, &iterator->status)) {
2260                 cleanup_tempfile_(tempfile, tempfilename);
2261                 return false;
2262         }
2263
2264         return true;
2265 }
2266
2267 FLAC__bool simple_iterator_copy_file_postfix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, int fixup_is_last_code, long fixup_is_last_flag_offset, FLAC__bool backup)
2268 {
2269         long save_offset = iterator->offset[iterator->depth]; /*@@@ 2G limit */
2270         FLAC__ASSERT(0 != *tempfile);
2271
2272         if(0 != fseek(iterator->file, save_offset + FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length, SEEK_SET)) {
2273                 cleanup_tempfile_(tempfile, tempfilename);
2274                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2275                 return false;
2276         }
2277         if(!copy_remaining_bytes_from_file_(iterator->file, *tempfile, &iterator->status)) {
2278                 cleanup_tempfile_(tempfile, tempfilename);
2279                 return false;
2280         }
2281
2282         if(fixup_is_last_code != 0) {
2283                 /*
2284                  * if code == 1, it means a block was appended to the end so
2285                  *   we have to clear the is_last flag of the previous block
2286                  * if code == -1, it means the last block was deleted so
2287                  *   we have to set the is_last flag of the previous block
2288                  */
2289                 /* MAGIC NUMBERs here; we know the is_last flag is the high bit of the byte at this location */
2290                 FLAC__byte x;
2291                 if(0 != fseek(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
2292                         cleanup_tempfile_(tempfile, tempfilename);
2293                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2294                         return false;
2295                 }
2296                 if(fread(&x, 1, 1, *tempfile) != 1) {
2297                         cleanup_tempfile_(tempfile, tempfilename);
2298                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2299                         return false;
2300                 }
2301                 if(fixup_is_last_code > 0) {
2302                         FLAC__ASSERT(x & 0x80);
2303                         x &= 0x7f;
2304                 }
2305                 else {
2306                         FLAC__ASSERT(!(x & 0x80));
2307                         x |= 0x80;
2308                 }
2309                 if(0 != fseek(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
2310                         cleanup_tempfile_(tempfile, tempfilename);
2311                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2312                         return false;
2313                 }
2314                 if(local__fwrite(&x, 1, 1, *tempfile) != 1) {
2315                         cleanup_tempfile_(tempfile, tempfilename);
2316                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2317                         return false;
2318                 }
2319         }
2320
2321         (void)fclose(iterator->file);
2322
2323         if(!transport_tempfile_(iterator->filename, tempfile, tempfilename, &iterator->status))
2324                 return false;
2325
2326         if(iterator->has_stats)
2327                 set_file_stats_(iterator->filename, &iterator->stats);
2328
2329         if(!simple_iterator_prime_input_(iterator, !iterator->is_writable))
2330                 return false;
2331         if(backup) {
2332                 while(iterator->offset[iterator->depth] + (long)FLAC__STREAM_METADATA_HEADER_LENGTH + (long)iterator->length < save_offset)
2333                         if(!FLAC__metadata_simple_iterator_next(iterator))
2334                                 return false;
2335                 return true;
2336         }
2337         else {
2338                 /* move the iterator to it's original block faster by faking a push, then doing a pop_ */
2339                 FLAC__ASSERT(iterator->depth == 0);
2340                 iterator->offset[0] = save_offset;
2341                 iterator->depth++;
2342                 return simple_iterator_pop_(iterator);
2343         }
2344 }
2345
2346 FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, unsigned bytes/*@@@ 4G limit*/, FLAC__Metadata_SimpleIteratorStatus *status)
2347 {
2348         FLAC__byte buffer[8192];
2349         unsigned n;
2350
2351         while(bytes > 0) {
2352                 n = min(sizeof(buffer), bytes);
2353                 if(fread(buffer, 1, n, file) != n) {
2354                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2355                         return false;
2356                 }
2357                 if(local__fwrite(buffer, 1, n, tempfile) != n) {
2358                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2359                         return false;
2360                 }
2361                 bytes -= n;
2362         }
2363
2364         return true;
2365 }
2366
2367 FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status)
2368 {
2369         FLAC__byte buffer[8192];
2370         size_t n;
2371
2372         while(!feof(file)) {
2373                 n = fread(buffer, 1, sizeof(buffer), file);
2374                 if(n == 0 && !feof(file)) {
2375                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2376                         return false;
2377                 }
2378                 if(n > 0 && local__fwrite(buffer, 1, n, tempfile) != n) {
2379                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2380                         return false;
2381                 }
2382         }
2383
2384         return true;
2385 }
2386
2387 FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
2388 {
2389         static const char *tempfile_suffix = ".metadata_edit";
2390         if(0 == tempfile_path_prefix) {
2391                 if(0 == (*tempfilename = (char*)malloc(strlen(filename) + strlen(tempfile_suffix) + 1))) {
2392                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2393                         return false;
2394                 }
2395                 strcpy(*tempfilename, filename);
2396                 strcat(*tempfilename, tempfile_suffix);
2397         }
2398         else {
2399                 const char *p = strrchr(filename, '/');
2400                 if(0 == p)
2401                         p = filename;
2402                 else
2403                         p++;
2404
2405                 if(0 == (*tempfilename = (char*)malloc(strlen(tempfile_path_prefix) + 1 + strlen(p) + strlen(tempfile_suffix) + 1))) {
2406                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2407                         return false;
2408                 }
2409                 strcpy(*tempfilename, tempfile_path_prefix);
2410                 strcat(*tempfilename, "/");
2411                 strcat(*tempfilename, p);
2412                 strcat(*tempfilename, tempfile_suffix);
2413         }
2414
2415         if(0 == (*tempfile = fopen(*tempfilename, "w+b"))) {
2416                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
2417                 return false;
2418         }
2419
2420         return true;
2421 }
2422
2423 FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
2424 {
2425         FLAC__ASSERT(0 != filename);
2426         FLAC__ASSERT(0 != tempfile);
2427         FLAC__ASSERT(0 != *tempfile);
2428         FLAC__ASSERT(0 != tempfilename);
2429         FLAC__ASSERT(0 != *tempfilename);
2430         FLAC__ASSERT(0 != status);
2431
2432         (void)fclose(*tempfile);
2433         *tempfile = 0;
2434
2435 #if defined _MSC_VER || defined __MINGW32__
2436         if(unlink(filename) < 0) {
2437                 cleanup_tempfile_(tempfile, tempfilename);
2438                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR;
2439                 return false;
2440         }
2441 #endif
2442
2443         /*@@@ to fully support the tempfile_path_prefix we need to update this piece to actually copy across filesystems instead of just rename(): */
2444         if(0 != rename(*tempfilename, filename)) {
2445                 cleanup_tempfile_(tempfile, tempfilename);
2446                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR;
2447                 return false;
2448         }
2449
2450         cleanup_tempfile_(tempfile, tempfilename);
2451
2452         return true;
2453 }
2454
2455 void cleanup_tempfile_(FILE **tempfile, char **tempfilename)
2456 {
2457         if(0 != *tempfile) {
2458                 (void)fclose(*tempfile);
2459                 *tempfile = 0;
2460         }
2461
2462         if(0 != *tempfilename) {
2463                 (void)unlink(*tempfilename);
2464                 free(*tempfilename);
2465                 *tempfilename = 0;
2466         }
2467 }
2468
2469 FLAC__bool get_file_stats_(const char *filename, struct stat *stats)
2470 {
2471         FLAC__ASSERT(0 != filename);
2472         FLAC__ASSERT(0 != stats);
2473         return (0 == stat(filename, stats));
2474 }
2475
2476 void set_file_stats_(const char *filename, struct stat *stats)
2477 {
2478         struct utimbuf srctime;
2479
2480         FLAC__ASSERT(0 != filename);
2481         FLAC__ASSERT(0 != stats);
2482
2483         srctime.actime = stats->st_atime;
2484         srctime.modtime = stats->st_mtime;
2485         (void)chmod(filename, stats->st_mode);
2486         (void)utime(filename, &srctime);
2487 #if !defined _MSC_VER && !defined __MINGW32__
2488         (void)chown(filename, stats->st_uid, -1);
2489         (void)chown(filename, -1, stats->st_gid);
2490 #endif
2491 }
2492
2493 FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status)
2494 {
2495         switch(status) {
2496                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK:
2497                         return FLAC__METADATA_CHAIN_STATUS_OK;
2498                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT:
2499                         return FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT;
2500                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE:
2501                         return FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
2502                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE:
2503                         return FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE;
2504                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE:
2505                         return FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE;
2506                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA:
2507                         return FLAC__METADATA_CHAIN_STATUS_BAD_METADATA;
2508                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR:
2509                         return FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
2510                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR:
2511                         return FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
2512                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR:
2513                         return FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
2514                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR:
2515                         return FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR;
2516                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR:
2517                         return FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR;
2518                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR:
2519                         return FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
2520                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR:
2521                 default:
2522                         return FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
2523         }
2524 }