src/libFLAC/metadata_iterators.c

   1 /* libFLAC - Free Lossless Audio Codec library
   2  * Copyright (C) 2001,2002  Josh Coalson
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Library General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Library General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Library General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA  02111-1307, USA.
  18  */
  19
  20 #if !defined _MSC_VER && !defined __MINGW32__
  21 /*@@@ don't know how to resolve errno without using LIBC.LIB; must use MSVCRT.LIB only for plugins */
  22 #include <errno.h>
  23 #endif
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27
  28 #if defined _MSC_VER || defined __MINGW32__
  29 #include <sys/utime.h> /* for utime() */
  30 #include <io.h> /* for chmod() */
  31 #else
  32 #include <sys/types.h> /* some flavors of BSD (like OS X) require this to get time_t */
  33 #include <utime.h> /* for utime() */
  34 #include <unistd.h> /* for chown(), unlink() */
  35 #endif
  36 #include <sys/stat.h> /* for stat(), maybe chmod() */
  37
  38 #include "private/metadata.h"
  39
  40 #include "FLAC/assert.h"
  41 #include "FLAC/file_decoder.h"
  42
  43 #ifdef max
  44 #undef max
  45 #endif
  46 #define max(a,b) ((a)>(b)?(a):(b))
  47 #ifdef min
  48 #undef min
  49 #endif
  50 #define min(a,b) ((a)<(b)?(a):(b))
  51
  52
  53 /****************************************************************************
  54  *
  55  * Local function declarations
  56  *
  57  ***************************************************************************/
  58
  59 static void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes);
  60 static void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes);
  61 static void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes);
  62 static FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes);
  63 static FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes);
  64 static FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes);
  65
  66 static FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator);
  67 static FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block);
  68 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_(FILE *file, FLAC__StreamMetadata_StreamInfo *block);
  69 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_padding_(FILE *file, FLAC__StreamMetadata_Padding *block, unsigned block_length);
  70 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_application_(FILE *file, FLAC__StreamMetadata_Application *block, unsigned block_length);
  71 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_seektable_(FILE *file, FLAC__StreamMetadata_SeekTable *block, unsigned block_length);
  72 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_entry_(FILE *file, FLAC__StreamMetadata_VorbisComment_Entry *entry);
  73 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_(FILE *file, FLAC__StreamMetadata_VorbisComment *block);
  74
  75 static FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block);
  76 static FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block);
  77 static FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_streaminfo_(FILE *file, const FLAC__StreamMetadata_StreamInfo *block);
  78 static FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_padding_(FILE *file, const FLAC__StreamMetadata_Padding *block, unsigned block_length);
  79 static FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_application_(FILE *file, const FLAC__StreamMetadata_Application *block, unsigned block_length);
  80 static FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_seektable_(FILE *file, const FLAC__StreamMetadata_SeekTable *block);
  81 static FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_vorbis_comment_(FILE *file, const FLAC__StreamMetadata_VorbisComment *block);
  82 static FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block);
  83 static FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last);
  84 static FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append);
  85
  86 static FLAC__bool chain_rewrite_chain_(FLAC__Metadata_Chain *chain);
  87 static FLAC__bool chain_rewrite_file_(FLAC__Metadata_Chain *chain, const char *tempfile_path_prefix);
  88
  89 static void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator);
  90 static FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator);
  91
  92 /* return 0 if OK, 1 if read error, 2 if not a FLAC file */
  93 static unsigned seek_to_first_metadata_block_(FILE *f);
  94
  95 static FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append);
  96 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);
  97
  98 static FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, unsigned bytes/*@@@ 4G limit*/, FLAC__Metadata_SimpleIteratorStatus *status);
  99 static FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status);
 100
 101 static FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status);
 102 static FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status);
 103 static void cleanup_tempfile_(FILE **tempfile, char **tempfilename);
 104
 105 static FLAC__bool get_file_stats_(const char *filename, struct stat *stats);
 106 static void set_file_stats_(const char *filename, struct stat *stats);
 107
 108 static FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status);
 109
 110
 111 /****************************************************************************
 112  *
 113  * Level 0 implementation
 114  *
 115  ***************************************************************************/
 116
 117 static FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__FileDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data);
 118 static void metadata_callback_(const FLAC__FileDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data);
 119 static void error_callback_(const FLAC__FileDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data);
 120
 121 typedef struct {
 122         FLAC__bool got_error;
 123         FLAC__bool got_streaminfo;
 124         FLAC__StreamMetadata *streaminfo;
 125 } level0_client_data;
 126
 127 FLAC__bool FLAC__metadata_get_streaminfo(const char *filename, FLAC__StreamMetadata *streaminfo)
 128 {
 129         level0_client_data cd;
 130         FLAC__FileDecoder *decoder = FLAC__file_decoder_new();
 131
 132         if(0 == decoder)
 133                 return false;
 134
 135         cd.got_error = false;
 136         cd.got_streaminfo = false;
 137         cd.streaminfo = streaminfo;
 138
 139         FLAC__file_decoder_set_md5_checking(decoder, false);
 140         FLAC__file_decoder_set_filename(decoder, filename);
 141         FLAC__file_decoder_set_write_callback(decoder, write_callback_);
 142         FLAC__file_decoder_set_metadata_callback(decoder, metadata_callback_);
 143         FLAC__file_decoder_set_error_callback(decoder, error_callback_);
 144         FLAC__file_decoder_set_client_data(decoder, &cd);
 145
 146         if(FLAC__file_decoder_init(decoder) != FLAC__FILE_DECODER_OK || cd.got_error) {
 147                 FLAC__file_decoder_finish(decoder);
 148                 FLAC__file_decoder_delete(decoder);
 149                 return false;
 150         }
 151
 152         if(!FLAC__file_decoder_process_metadata(decoder) || cd.got_error) {
 153                 FLAC__file_decoder_finish(decoder);
 154                 FLAC__file_decoder_delete(decoder);
 155                 return false;
 156         }
 157
 158         FLAC__file_decoder_finish(decoder);
 159         FLAC__file_decoder_delete(decoder);
 160
 161         return !cd.got_error && cd.got_streaminfo;
 162 }
 163
 164 FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__FileDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
 165 {
 166         (void)decoder, (void)frame, (void)buffer, (void)client_data;
 167
 168         return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;
 169 }
 170
 171 void metadata_callback_(const FLAC__FileDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
 172 {
 173         level0_client_data *cd = (level0_client_data *)client_data;
 174         (void)decoder;
 175
 176         if(metadata->type == FLAC__METADATA_TYPE_STREAMINFO && 0 != cd->streaminfo) {
 177                 *(cd->streaminfo) = *metadata;
 178                 cd->got_streaminfo = true;
 179         }
 180 }
 181
 182 void error_callback_(const FLAC__FileDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
 183 {
 184         level0_client_data *cd = (level0_client_data *)client_data;
 185         (void)decoder;
 186
 187         if(status != FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC)
 188                 cd->got_error = true;
 189 }
 190
 191
 192 /****************************************************************************
 193  *
 194  * Level 1 implementation
 195  *
 196  ***************************************************************************/
 197
 198 #define SIMPLE_ITERATOR_MAX_PUSH_DEPTH (1+4)
 199 /* 1 for initial offset, +4 for our own personal use */
 200
 201 struct FLAC__Metadata_SimpleIterator {
 202         FILE *file;
 203         char *filename, *tempfile_path_prefix;
 204         struct stat stats;
 205         FLAC__bool has_stats;
 206         FLAC__bool is_writable;
 207         FLAC__Metadata_SimpleIteratorStatus status;
 208         /*@@@ 2G limits here because of the offset type: */
 209         long offset[SIMPLE_ITERATOR_MAX_PUSH_DEPTH];
 210         long first_offset; /* this is the offset to the STREAMINFO block */
 211         unsigned depth;
 212         /* this is the metadata block header of the current block we are pointing to: */
 213         FLAC__bool is_last;
 214         FLAC__MetadataType type;
 215         unsigned length;
 216 };
 217
 218 const char * const FLAC__Metadata_SimpleIteratorStatusString[] = {
 219         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK",
 220         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT",
 221         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE",
 222         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE",
 223         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE",
 224         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA",
 225         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR",
 226         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR",
 227         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR",
 228         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR",
 229         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR",
 230         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR",
 231         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR"
 232 };
 233
 234
 235 FLAC__Metadata_SimpleIterator *FLAC__metadata_simple_iterator_new()
 236 {
 237         FLAC__Metadata_SimpleIterator *iterator = malloc(sizeof(FLAC__Metadata_SimpleIterator));
 238
 239         if(0 != iterator) {
 240                 iterator->file = 0;
 241                 iterator->filename = 0;
 242                 iterator->tempfile_path_prefix = 0;
 243                 iterator->has_stats = false;
 244                 iterator->is_writable = false;
 245                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
 246                 iterator->first_offset = iterator->offset[0] = -1;
 247                 iterator->depth = 0;
 248         }
 249
 250         return iterator;
 251 }
 252
 253 static void simple_iterator_free_guts_(FLAC__Metadata_SimpleIterator *iterator)
 254 {
 255         FLAC__ASSERT(0 != iterator);
 256
 257         if(0 != iterator->file) {
 258                 fclose(iterator->file);
 259                 iterator->file = 0;
 260                 if(iterator->has_stats)
 261                         set_file_stats_(iterator->filename, &iterator->stats);
 262         }
 263         if(0 != iterator->filename) {
 264                 free(iterator->filename);
 265                 iterator->filename = 0;
 266         }
 267         if(0 != iterator->tempfile_path_prefix) {
 268                 free(iterator->tempfile_path_prefix);
 269                 iterator->tempfile_path_prefix = 0;
 270         }
 271 }
 272
 273 void FLAC__metadata_simple_iterator_delete(FLAC__Metadata_SimpleIterator *iterator)
 274 {
 275         FLAC__ASSERT(0 != iterator);
 276
 277         simple_iterator_free_guts_(iterator);
 278         free(iterator);
 279 }
 280
 281 FLAC__Metadata_SimpleIteratorStatus FLAC__metadata_simple_iterator_status(FLAC__Metadata_SimpleIterator *iterator)
 282 {
 283         FLAC__Metadata_SimpleIteratorStatus status;
 284
 285         FLAC__ASSERT(0 != iterator);
 286
 287         status = iterator->status;
 288         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
 289         return status;
 290 }
 291
 292 static FLAC__bool simple_iterator_prime_input_(FLAC__Metadata_SimpleIterator *iterator)
 293 {
 294         unsigned ret;
 295
 296         FLAC__ASSERT(0 != iterator);
 297
 298         iterator->is_writable = false;
 299
 300         if(0 == (iterator->file = fopen(iterator->filename, "r+b"))) {
 301 #if !defined _MSC_VER && !defined __MINGW32__
 302 /*@@@ don't know how to resolve errno without using LIBC.LIB; must use MSVCRT.LIB only for plugins */
 303                 if(errno == EACCES) {
 304 #endif
 305                         if(0 == (iterator->file = fopen(iterator->filename, "rb"))) {
 306                                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
 307                                 return false;
 308                         }
 309 #if !defined _MSC_VER && !defined __MINGW32__
 310                 }
 311 #endif
 312                 else {
 313                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
 314                         return false;
 315                 }
 316         }
 317         else {
 318                 iterator->is_writable = true;
 319         }
 320
 321         ret = seek_to_first_metadata_block_(iterator->file);
 322         switch(ret) {
 323                 case 0:
 324                         iterator->depth = 0;
 325                         iterator->first_offset = iterator->offset[iterator->depth] = ftell(iterator->file);
 326                         return read_metadata_block_header_(iterator);
 327                 case 1:
 328                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
 329                         return false;
 330                 case 2:
 331                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE;
 332                         return false;
 333                 default:
 334                         FLAC__ASSERT(0);
 335                         return false;
 336         }
 337 }
 338
 339 #if 0
 340 @@@ If we decide to finish implementing this, put this comment back in metadata.h
 341 /*
 342  * The 'tempfile_path_prefix' allows you to specify a directory where
 343  * tempfiles should go.  Remember that if your metadata edits cause the
 344  * FLAC file to grow, the entire file will have to be rewritten.  If
 345  * 'tempfile_path_prefix' is NULL, the temp file will be written in the
 346  * same directory as the original FLAC file.  This makes replacing the
 347  * original with the tempfile fast but requires extra space in the same
 348  * partition for the tempfile.  If space is a problem, you can pass a
 349  * directory name belonging to a different partition in
 350  * 'tempfile_path_prefix'.  Note that you should use the forward slash
 351  * '/' as the directory separator.  A trailing slash is not needed; it
 352  * will be added automatically.
 353  */
 354 FLAC__bool FLAC__metadata_simple_iterator_init(FLAC__Metadata_SimpleIterator *iterator, const char *filename, FLAC__bool preserve_file_stats, const char *tempfile_path_prefix);
 355 #endif
 356
 357 FLAC__bool FLAC__metadata_simple_iterator_init(FLAC__Metadata_SimpleIterator *iterator, const char *filename, FLAC__bool preserve_file_stats)
 358 {
 359         const char *tempfile_path_prefix = 0; /*@@@ search for comments near 'rename(...)' for what it will take to finish implementing this */
 360
 361         FLAC__ASSERT(0 != iterator);
 362         FLAC__ASSERT(0 != filename);
 363
 364         simple_iterator_free_guts_(iterator);
 365
 366         if(preserve_file_stats)
 367                 iterator->has_stats = get_file_stats_(filename, &iterator->stats);
 368
 369         if(0 == (iterator->filename = strdup(filename))) {
 370                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 371                 return false;
 372         }
 373         if(0 != tempfile_path_prefix && 0 == (iterator->tempfile_path_prefix = strdup(tempfile_path_prefix))) {
 374                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 375                 return false;
 376         }
 377
 378         return simple_iterator_prime_input_(iterator);
 379 }
 380
 381 FLAC__bool FLAC__metadata_simple_iterator_is_writable(const FLAC__Metadata_SimpleIterator *iterator)
 382 {
 383         FLAC__ASSERT(0 != iterator);
 384         FLAC__ASSERT(0 != iterator->file);
 385
 386         return iterator->is_writable;
 387 }
 388
 389 FLAC__bool FLAC__metadata_simple_iterator_next(FLAC__Metadata_SimpleIterator *iterator)
 390 {
 391         FLAC__ASSERT(0 != iterator);
 392         FLAC__ASSERT(0 != iterator->file);
 393
 394         if(iterator->is_last)
 395                 return false;
 396
 397         if(0 != fseek(iterator->file, iterator->length, SEEK_CUR)) {
 398                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 399                 return false;
 400         }
 401
 402         iterator->offset[iterator->depth] = ftell(iterator->file);
 403
 404         return read_metadata_block_header_(iterator);
 405 }
 406
 407 FLAC__bool FLAC__metadata_simple_iterator_prev(FLAC__Metadata_SimpleIterator *iterator)
 408 {
 409         long this_offset;
 410
 411         FLAC__ASSERT(0 != iterator);
 412         FLAC__ASSERT(0 != iterator->file);
 413
 414         if(iterator->offset[iterator->depth] == iterator->first_offset)
 415                 return false;
 416
 417         if(0 != fseek(iterator->file, iterator->first_offset, SEEK_SET)) {
 418                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 419                 return false;
 420         }
 421         this_offset = iterator->first_offset;
 422         if(!read_metadata_block_header_(iterator))
 423                 return false;
 424
 425         /* we ignore any error from ftell() and catch it in fseek() */
 426         while(ftell(iterator->file) + (long)iterator->length < iterator->offset[iterator->depth]) {
 427                 if(0 != fseek(iterator->file, iterator->length, SEEK_CUR)) {
 428                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 429                         return false;
 430                 }
 431                 this_offset = ftell(iterator->file);
 432                 if(!read_metadata_block_header_(iterator))
 433                         return false;
 434         }
 435
 436         iterator->offset[iterator->depth] = this_offset;
 437
 438         return true;
 439 }
 440
 441 FLAC__MetadataType FLAC__metadata_simple_iterator_get_block_type(const FLAC__Metadata_SimpleIterator *iterator)
 442 {
 443         FLAC__ASSERT(0 != iterator);
 444         FLAC__ASSERT(0 != iterator->file);
 445
 446         return iterator->type;
 447 }
 448
 449 FLAC__StreamMetadata *FLAC__metadata_simple_iterator_get_block(FLAC__Metadata_SimpleIterator *iterator)
 450 {
 451         FLAC__StreamMetadata *block = FLAC__metadata_object_new(iterator->type);
 452
 453         FLAC__ASSERT(0 != iterator);
 454         FLAC__ASSERT(0 != iterator->file);
 455
 456         if(0 != block) {
 457                 block->is_last = iterator->is_last;
 458                 block->length = iterator->length;
 459
 460                 if(!read_metadata_block_data_(iterator, block)) {
 461                         FLAC__metadata_object_delete(block);
 462                         return 0;
 463                 }
 464
 465                 /* back up to the beginning of the block data to stay consistent */
 466                 if(0 != fseek(iterator->file, iterator->offset[iterator->depth] + FLAC__STREAM_METADATA_HEADER_LENGTH, SEEK_SET)) {
 467                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 468                         FLAC__metadata_object_delete(block);
 469                         return 0;
 470                 }
 471         }
 472         else
 473                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 474
 475         return block;
 476 }
 477
 478 FLAC__bool FLAC__metadata_simple_iterator_set_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding)
 479 {
 480         FLAC__ASSERT_DECLARATION(long debug_target_offset = iterator->offset[iterator->depth];)
 481         FLAC__bool ret;
 482
 483         FLAC__ASSERT(0 != iterator);
 484         FLAC__ASSERT(0 != iterator->file);
 485
 486         if(!iterator->is_writable) {
 487                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE;
 488                 return false;
 489         }
 490
 491         if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO || block->type == FLAC__METADATA_TYPE_STREAMINFO) {
 492                 if(iterator->type != block->type) {
 493                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 494                         return false;
 495                 }
 496         }
 497
 498         block->is_last = iterator->is_last;
 499
 500         if(iterator->length == block->length)
 501                 return write_metadata_block_stationary_(iterator, block);
 502         else if(iterator->length > block->length) {
 503                 if(use_padding && iterator->length >= FLAC__STREAM_METADATA_HEADER_LENGTH + block->length) {
 504                         ret =  write_metadata_block_stationary_with_padding_(iterator, block, iterator->length - FLAC__STREAM_METADATA_HEADER_LENGTH - block->length, block->is_last);
 505                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 506                         FLAC__ASSERT(ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 507                         return ret;
 508                 }
 509                 else {
 510                         ret = rewrite_whole_file_(iterator, block, /*append=*/false);
 511                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 512                         FLAC__ASSERT(ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 513                         return ret;
 514                 }
 515         }
 516         else /* iterator->length < block->length */ {
 517                 unsigned padding_leftover = 0;
 518                 FLAC__bool padding_is_last = false;
 519                 if(use_padding) {
 520                         /* first see if we can even use padding */
 521                         if(iterator->is_last) {
 522                                 use_padding = false;
 523                         }
 524                         else {
 525                                 const unsigned extra_padding_bytes_required = block->length - iterator->length;
 526                                 simple_iterator_push_(iterator);
 527                                 if(!FLAC__metadata_simple_iterator_next(iterator)) {
 528                                         (void)simple_iterator_pop_(iterator);
 529                                         return false;
 530                                 }
 531                                 if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
 532                                         use_padding = false;
 533                                 }
 534                                 else {
 535                                         if(FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length == extra_padding_bytes_required) {
 536                                                 padding_leftover = 0;
 537                                                 block->is_last = iterator->is_last;
 538                                         }
 539                                         else if(iterator->length < extra_padding_bytes_required)
 540                                                 use_padding = false;
 541                                         else {
 542                                                 padding_leftover = FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length - extra_padding_bytes_required;
 543                                                 padding_is_last = iterator->is_last;
 544                                                 block->is_last = false;
 545                                         }
 546                                 }
 547                                 if(!simple_iterator_pop_(iterator))
 548                                         return false;
 549                         }
 550                 }
 551                 if(use_padding) {
 552                         if(padding_leftover == 0) {
 553                                 ret = write_metadata_block_stationary_(iterator, block);
 554                                 FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 555                                 FLAC__ASSERT(ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 556                                 return ret;
 557                         }
 558                         else {
 559                                 FLAC__ASSERT(padding_leftover >= FLAC__STREAM_METADATA_HEADER_LENGTH);
 560                                 ret = write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover - FLAC__STREAM_METADATA_HEADER_LENGTH, padding_is_last);
 561                                 FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 562                                 FLAC__ASSERT(ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 563                                 return ret;
 564                         }
 565                 }
 566                 else {
 567                         ret = rewrite_whole_file_(iterator, block, /*append=*/false);
 568                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 569                         FLAC__ASSERT(ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 570                         return ret;
 571                 }
 572         }
 573 }
 574
 575 FLAC__bool FLAC__metadata_simple_iterator_insert_block_after(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding)
 576 {
 577         unsigned padding_leftover = 0;
 578         FLAC__bool padding_is_last = false;
 579
 580         FLAC__ASSERT_DECLARATION(long debug_target_offset = iterator->offset[iterator->depth] + FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length;)
 581         FLAC__bool ret;
 582
 583         FLAC__ASSERT(0 != iterator);
 584         FLAC__ASSERT(0 != iterator->file);
 585
 586         if(!iterator->is_writable)
 587                 return false;
 588
 589         if(block->type == FLAC__METADATA_TYPE_STREAMINFO) {
 590                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 591                 return false;
 592         }
 593
 594         block->is_last = iterator->is_last;
 595
 596         if(use_padding) {
 597                 /* first see if we can even use padding */
 598                 if(iterator->is_last) {
 599                         use_padding = false;
 600                 }
 601                 else {
 602                         simple_iterator_push_(iterator);
 603                         if(!FLAC__metadata_simple_iterator_next(iterator)) {
 604                                 (void)simple_iterator_pop_(iterator);
 605                                 return false;
 606                         }
 607                         if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
 608                                 use_padding = false;
 609                         }
 610                         else {
 611                                 if(iterator->length == block->length) {
 612                                         padding_leftover = 0;
 613                                         block->is_last = iterator->is_last;
 614                                 }
 615                                 else if(iterator->length < FLAC__STREAM_METADATA_HEADER_LENGTH + block->length)
 616                                         use_padding = false;
 617                                 else {
 618                                         padding_leftover = iterator->length - block->length;
 619                                         padding_is_last = iterator->is_last;
 620                                         block->is_last = false;
 621                                 }
 622                         }
 623                         if(!simple_iterator_pop_(iterator))
 624                                 return false;
 625                 }
 626         }
 627         if(use_padding) {
 628                 /* move to the next block, which is suitable padding */
 629                 if(!FLAC__metadata_simple_iterator_next(iterator))
 630                         return false;
 631                 if(padding_leftover == 0) {
 632                         ret = write_metadata_block_stationary_(iterator, block);
 633                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 634                         FLAC__ASSERT(ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 635                         return ret;
 636                 }
 637                 else {
 638                         FLAC__ASSERT(padding_leftover >= FLAC__STREAM_METADATA_HEADER_LENGTH);
 639                         ret = write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover - FLAC__STREAM_METADATA_HEADER_LENGTH, padding_is_last);
 640                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 641                         FLAC__ASSERT(ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 642                         return ret;
 643                 }
 644         }
 645         else {
 646                 ret = rewrite_whole_file_(iterator, block, /*append=*/true);
 647                 FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 648                 FLAC__ASSERT(ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 649                 return ret;
 650         }
 651 }
 652
 653 FLAC__bool FLAC__metadata_simple_iterator_delete_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool use_padding)
 654 {
 655         FLAC__ASSERT_DECLARATION(long debug_target_offset = iterator->offset[iterator->depth];)
 656         FLAC__bool ret;
 657
 658         if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO) {
 659                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 660                 return false;
 661         }
 662
 663         if(use_padding) {
 664                 FLAC__StreamMetadata *padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING);
 665                 if(0 == padding) {
 666                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 667                         return false;
 668                 }
 669                 padding->length = iterator->length;
 670                 if(!FLAC__metadata_simple_iterator_set_block(iterator, padding, false)) {
 671                         FLAC__metadata_object_delete(padding);
 672                         return false;
 673                 }
 674                 FLAC__metadata_object_delete(padding);
 675                 if(!FLAC__metadata_simple_iterator_prev(iterator))
 676                         return false;
 677                 FLAC__ASSERT(iterator->offset[iterator->depth] + (long)FLAC__STREAM_METADATA_HEADER_LENGTH + (long)iterator->length == debug_target_offset);
 678                 FLAC__ASSERT(ftell(iterator->file) + (long)iterator->length == debug_target_offset);
 679                 return true;
 680         }
 681         else {
 682                 ret = rewrite_whole_file_(iterator, 0, /*append=*/false);
 683                 FLAC__ASSERT(iterator->offset[iterator->depth] + (long)FLAC__STREAM_METADATA_HEADER_LENGTH + (long)iterator->length == debug_target_offset);
 684                 FLAC__ASSERT(ftell(iterator->file) + (long)iterator->length == debug_target_offset);
 685                 return ret;
 686         }
 687 }
 688
 689
 690
 691 /****************************************************************************
 692  *
 693  * Level 2 implementation
 694  *
 695  ***************************************************************************/
 696
 697
 698 typedef struct FLAC__Metadata_Node {
 699         FLAC__StreamMetadata *data;
 700         struct FLAC__Metadata_Node *prev, *next;
 701 } FLAC__Metadata_Node;
 702
 703 struct FLAC__Metadata_Chain {
 704         char *filename;
 705         FLAC__Metadata_Node *head;
 706         FLAC__Metadata_Node *tail;
 707         unsigned nodes;
 708         FLAC__Metadata_ChainStatus status;
 709         long first_offset, last_offset; /*@@@ 2G limit */
 710         /*
 711          * This is the length of the chain initially read from the FLAC file.
 712          * it is used to compare against the current_length to decide whether
 713          * or not the whole file has to be rewritten.
 714          */
 715         unsigned initial_length; /*@@@ 4G limit */
 716         unsigned current_length; /*@@@ 4G limit */
 717 };
 718
 719 struct FLAC__Metadata_Iterator {
 720         FLAC__Metadata_Chain *chain;
 721         FLAC__Metadata_Node *current;
 722 };
 723
 724 const char * const FLAC__Metadata_ChainStatusString[] = {
 725         "FLAC__METADATA_CHAIN_STATUS_OK",
 726         "FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT",
 727         "FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE",
 728         "FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE",
 729         "FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE",
 730         "FLAC__METADATA_CHAIN_STATUS_BAD_METADATA",
 731         "FLAC__METADATA_CHAIN_STATUS_READ_ERROR",
 732         "FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR",
 733         "FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR",
 734         "FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR",
 735         "FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR",
 736         "FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR",
 737         "FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR"
 738 };
 739
 740
 741 static FLAC__Metadata_Node *node_new_()
 742 {
 743         FLAC__Metadata_Node *node = (FLAC__Metadata_Node*)malloc(sizeof(FLAC__Metadata_Node));
 744         if(0 != node)
 745                 memset(node, 0, sizeof(FLAC__Metadata_Node));
 746         return node;
 747 }
 748
 749 static void node_delete_(FLAC__Metadata_Node *node)
 750 {
 751         FLAC__ASSERT(0 != node);
 752         if(0 != node->data)
 753                 FLAC__metadata_object_delete(node->data);
 754         free(node);
 755 }
 756
 757 static void chain_append_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 758 {
 759         FLAC__ASSERT(0 != chain);
 760         FLAC__ASSERT(0 != node);
 761         FLAC__ASSERT(0 != node->data);
 762
 763         node->next = node->prev = 0;
 764         node->data->is_last = true;
 765         if(0 != chain->tail)
 766                 chain->tail->data->is_last = false;
 767
 768         if(0 == chain->head)
 769                 chain->head = node;
 770         else {
 771                 FLAC__ASSERT(0 != chain->tail);
 772                 chain->tail->next = node;
 773                 node->prev = chain->tail;
 774         }
 775         chain->tail = node;
 776         chain->nodes++;
 777         chain->current_length += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
 778 }
 779
 780 static void chain_remove_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 781 {
 782         FLAC__ASSERT(0 != chain);
 783         FLAC__ASSERT(0 != node);
 784
 785         if(node == chain->head)
 786                 chain->head = node->next;
 787         else
 788                 node->prev->next = node->next;
 789
 790         if(node == chain->tail)
 791                 chain->tail = node->prev;
 792         else
 793                 node->next->prev = node->prev;
 794
 795         if(0 != chain->tail)
 796                 chain->tail->data->is_last = true;
 797
 798         chain->nodes--;
 799         chain->current_length -= (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
 800 }
 801
 802 static void chain_delete_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 803 {
 804         chain_remove_node_(chain, node);
 805         node_delete_(node);
 806 }
 807
 808 static void iterator_insert_node_(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Node *node)
 809 {
 810         FLAC__ASSERT(0 != node);
 811         FLAC__ASSERT(0 != node->data);
 812         FLAC__ASSERT(0 != iterator);
 813         FLAC__ASSERT(0 != iterator->current);
 814         FLAC__ASSERT(0 != iterator->chain);
 815         FLAC__ASSERT(0 != iterator->chain->head);
 816         FLAC__ASSERT(0 != iterator->chain->tail);
 817
 818         node->data->is_last = false;
 819
 820         node->prev = iterator->current->prev;
 821         node->next = iterator->current;
 822
 823         if(0 == node->prev)
 824                 iterator->chain->head = node;
 825         else
 826                 node->prev->next = node;
 827
 828         iterator->current->prev = node;
 829
 830         iterator->chain->nodes++;
 831         iterator->chain->current_length += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
 832 }
 833
 834 static void iterator_insert_node_after_(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Node *node)
 835 {
 836         FLAC__ASSERT(0 != node);
 837         FLAC__ASSERT(0 != node->data);
 838         FLAC__ASSERT(0 != iterator);
 839         FLAC__ASSERT(0 != iterator->current);
 840         FLAC__ASSERT(0 != iterator->chain);
 841         FLAC__ASSERT(0 != iterator->chain->head);
 842         FLAC__ASSERT(0 != iterator->chain->tail);
 843
 844         iterator->current->data->is_last = false;
 845
 846         node->prev = iterator->current;
 847         node->next = iterator->current->next;
 848
 849         if(0 == node->next)
 850                 iterator->chain->tail = node;
 851         else
 852                 node->next->prev = node;
 853
 854         node->prev->next = node;
 855
 856         iterator->chain->tail->data->is_last = true;
 857
 858         iterator->chain->nodes++;
 859         iterator->chain->current_length += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
 860 }
 861
 862 /* return true iff node and node->next are both padding */
 863 static FLAC__bool chain_merge_adjacent_padding_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 864 {
 865         if(node->data->type == FLAC__METADATA_TYPE_PADDING && 0 != node->next && node->next->data->type == FLAC__METADATA_TYPE_PADDING) {
 866                 const unsigned growth = FLAC__STREAM_METADATA_HEADER_LENGTH + node->next->data->length;
 867                 node->data->length += growth;
 868                 chain->current_length += growth;
 869
 870                 chain_delete_node_(chain, node->next);
 871                 return true;
 872         }
 873         else
 874                 return false;
 875 }
 876
 877 FLAC__Metadata_Chain *FLAC__metadata_chain_new()
 878 {
 879         FLAC__Metadata_Chain *chain = malloc(sizeof(FLAC__Metadata_Chain));
 880
 881         if(0 != chain) {
 882                 chain->filename = 0;
 883                 chain->head = chain->tail = 0;
 884                 chain->nodes = 0;
 885                 chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
 886                 chain->initial_length = chain->current_length = 0;
 887         }
 888
 889         return chain;
 890 }
 891
 892 void FLAC__metadata_chain_delete(FLAC__Metadata_Chain *chain)
 893 {
 894         FLAC__Metadata_Node *node, *next;
 895
 896         FLAC__ASSERT(0 != chain);
 897
 898         for(node = chain->head; node; ) {
 899                 next = node->next;
 900                 node_delete_(node);
 901                 node = next;
 902         }
 903
 904         if(0 != chain->filename)
 905                 free(chain->filename);
 906
 907         free(chain);
 908 }
 909
 910 FLAC__Metadata_ChainStatus FLAC__metadata_chain_status(FLAC__Metadata_Chain *chain)
 911 {
 912         FLAC__Metadata_ChainStatus status;
 913
 914         FLAC__ASSERT(0 != chain);
 915
 916         status = chain->status;
 917         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
 918         return status;
 919 }
 920
 921 FLAC__bool FLAC__metadata_chain_read(FLAC__Metadata_Chain *chain, const char *filename)
 922 {
 923         FLAC__Metadata_SimpleIterator *iterator;
 924         FLAC__Metadata_Node *node;
 925
 926         FLAC__ASSERT(0 != chain);
 927         FLAC__ASSERT(0 != filename);
 928
 929         if(0 == (chain->filename = strdup(filename))) {
 930                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
 931                 return false;
 932         }
 933
 934         if(0 == (iterator = FLAC__metadata_simple_iterator_new())) {
 935                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
 936                 return false;
 937         }
 938
 939         if(!FLAC__metadata_simple_iterator_init(iterator, filename, /*preserve_file_stats=*/false)) {
 940                 chain->status = get_equivalent_status_(iterator->status);
 941                 return false;
 942         }
 943
 944         chain->first_offset = iterator->offset[iterator->depth];
 945
 946         do {
 947                 node = node_new_();
 948                 if(0 == node) {
 949                         chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
 950                         return false;
 951                 }
 952                 node->data = FLAC__metadata_simple_iterator_get_block(iterator);
 953                 if(0 == node->data) {
 954                         node_delete_(node);
 955                         chain->status = get_equivalent_status_(iterator->status);
 956                         return false;
 957                 }
 958                 chain_append_node_(chain, node);
 959         } while(FLAC__metadata_simple_iterator_next(iterator));
 960
 961         if(!iterator->is_last || iterator->status != FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK) {
 962                 chain->status = get_equivalent_status_(iterator->status);
 963                 return false;
 964         }
 965
 966         chain->last_offset = ftell(iterator->file) + iterator->length;
 967         FLAC__metadata_simple_iterator_delete(iterator);
 968
 969         chain->initial_length = chain->current_length;
 970         return true;
 971 }
 972
 973 FLAC__bool FLAC__metadata_chain_write(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__bool preserve_file_stats)
 974 {
 975         struct stat stats;
 976         const char *tempfile_path_prefix = 0;
 977
 978         if(use_padding) {
 979                 if(chain->current_length < chain->initial_length && chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
 980                         const unsigned delta = chain->initial_length - chain->current_length;
 981                         chain->tail->data->length += delta;
 982                         chain->current_length += delta;
 983                         FLAC__ASSERT(chain->current_length == chain->initial_length);
 984                 }
 985                 else if(chain->current_length + FLAC__STREAM_METADATA_HEADER_LENGTH <= chain->initial_length) {
 986                         FLAC__StreamMetadata *padding;
 987                         FLAC__Metadata_Node *node;
 988                         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING))) {
 989                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
 990                                 return false;
 991                         }
 992                         padding->length = chain->initial_length - (FLAC__STREAM_METADATA_HEADER_LENGTH + chain->current_length);
 993                         if(0 == (node = node_new_())) {
 994                                 FLAC__metadata_object_delete(padding);
 995                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
 996                                 return false;
 997                         }
 998                         node->data = padding;
 999                         chain_append_node_(chain, node);
1000                         FLAC__ASSERT(chain->current_length == chain->initial_length);
1001                 }
1002                 else if(chain->current_length > chain->initial_length) {
1003                         const unsigned delta = chain->current_length - chain->initial_length;
1004                         if(chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1005                                 if(chain->tail->data->length + FLAC__STREAM_METADATA_HEADER_LENGTH == delta) {
1006                                         chain_delete_node_(chain, chain->tail);
1007                                         FLAC__ASSERT(chain->current_length == chain->initial_length);
1008                                 }
1009                                 else if(chain->tail->data->length >= delta) {
1010                                         chain->tail->data->length -= delta;
1011                                         chain->current_length -= delta;
1012                                         FLAC__ASSERT(chain->current_length == chain->initial_length);
1013                                 }
1014                         }
1015                 }
1016         }
1017
1018         if(preserve_file_stats)
1019                 get_file_stats_(chain->filename, &stats);
1020
1021         if(chain->current_length == chain->initial_length) {
1022                 if(!chain_rewrite_chain_(chain))
1023                         return false;
1024         }
1025         else {
1026                 if(!chain_rewrite_file_(chain, tempfile_path_prefix))
1027                         return false;
1028         }
1029
1030         if(preserve_file_stats)
1031                 set_file_stats_(chain->filename, &stats);
1032
1033         /* recompute lengths and offsets if necessary */
1034         if(chain->initial_length != chain->current_length) {
1035                 const FLAC__Metadata_Node *node;
1036                 chain->initial_length = chain->current_length;
1037                 chain->last_offset = chain->first_offset;
1038                 for(node = chain->head; node; node = node->next)
1039                         chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1040         }
1041
1042         return true;
1043 }
1044
1045 void FLAC__metadata_chain_merge_padding(FLAC__Metadata_Chain *chain)
1046 {
1047         FLAC__Metadata_Node *node;
1048
1049         FLAC__ASSERT(0 != chain);
1050
1051         for(node = chain->head; node; ) {
1052                 if(!chain_merge_adjacent_padding_(chain, node))
1053                         node = node->next;
1054         }
1055 }
1056
1057 void FLAC__metadata_chain_sort_padding(FLAC__Metadata_Chain *chain)
1058 {
1059         FLAC__Metadata_Node *node, *save;
1060         unsigned i;
1061
1062         FLAC__ASSERT(0 != chain);
1063
1064         /*
1065          * Don't try and be too smart... this simple algo is good enough for
1066          * the small number of nodes that we deal with.
1067          */
1068         for(i = 0, node = chain->head; i < chain->nodes; i++) {
1069                 if(node->data->type == FLAC__METADATA_TYPE_PADDING) {
1070                         save = node->next;
1071                         chain_remove_node_(chain, node);
1072                         chain_append_node_(chain, node);
1073                         node = save;
1074                 }
1075                 else {
1076                         node = node->next;
1077                 }
1078         }
1079
1080         FLAC__metadata_chain_merge_padding(chain);
1081 }
1082
1083
1084 FLAC__Metadata_Iterator *FLAC__metadata_iterator_new()
1085 {
1086         FLAC__Metadata_Iterator *iterator = malloc(sizeof(FLAC__Metadata_Iterator));
1087
1088         if(0 != iterator) {
1089                 iterator->current = 0;
1090                 iterator->chain = 0;
1091         }
1092
1093         return iterator;
1094 }
1095
1096 void FLAC__metadata_iterator_delete(FLAC__Metadata_Iterator *iterator)
1097 {
1098         FLAC__ASSERT(0 != iterator);
1099
1100         free(iterator);
1101 }
1102
1103 /*
1104  * Initialize the iterator to point to the first metadata block in the
1105  * given chain.
1106  */
1107 void FLAC__metadata_iterator_init(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Chain *chain)
1108 {
1109         FLAC__ASSERT(0 != iterator);
1110         FLAC__ASSERT(0 != chain);
1111         FLAC__ASSERT(0 != chain->head);
1112
1113         iterator->chain = chain;
1114         iterator->current = chain->head;
1115 }
1116
1117 FLAC__bool FLAC__metadata_iterator_next(FLAC__Metadata_Iterator *iterator)
1118 {
1119         FLAC__ASSERT(0 != iterator);
1120
1121         if(0 == iterator->current || 0 == iterator->current->next)
1122                 return false;
1123
1124         iterator->current = iterator->current->next;
1125         return true;
1126 }
1127
1128 FLAC__bool FLAC__metadata_iterator_prev(FLAC__Metadata_Iterator *iterator)
1129 {
1130         FLAC__ASSERT(0 != iterator);
1131
1132         if(0 == iterator->current || 0 == iterator->current->prev)
1133                 return false;
1134
1135         iterator->current = iterator->current->prev;
1136         return true;
1137 }
1138
1139 FLAC__MetadataType FLAC__metadata_iterator_get_block_type(const FLAC__Metadata_Iterator *iterator)
1140 {
1141         FLAC__ASSERT(0 != iterator);
1142         FLAC__ASSERT(0 != iterator->current);
1143         FLAC__ASSERT(0 != iterator->current->data);
1144
1145         return iterator->current->data->type;
1146 }
1147
1148 FLAC__StreamMetadata *FLAC__metadata_iterator_get_block(FLAC__Metadata_Iterator *iterator)
1149 {
1150         FLAC__ASSERT(0 != iterator);
1151         FLAC__ASSERT(0 != iterator->current);
1152
1153         return iterator->current->data;
1154 }
1155
1156 FLAC__bool FLAC__metadata_iterator_set_block(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1157 {
1158         return FLAC__metadata_iterator_delete_block(iterator, false) && FLAC__metadata_iterator_insert_block_after(iterator, block);
1159 }
1160
1161 FLAC__bool FLAC__metadata_iterator_delete_block(FLAC__Metadata_Iterator *iterator, FLAC__bool replace_with_padding)
1162 {
1163         FLAC__Metadata_Node *save;
1164
1165         FLAC__ASSERT(0 != iterator);
1166         FLAC__ASSERT(0 != iterator->current);
1167
1168         if(0 == iterator->current->prev) {
1169                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1170                 return false;
1171         }
1172
1173         save = iterator->current->prev;
1174
1175         if(replace_with_padding) {
1176                 FLAC__metadata_object_delete_data(iterator->current->data);
1177                 iterator->current->data->type = FLAC__METADATA_TYPE_PADDING;
1178         }
1179         else {
1180                 chain_delete_node_(iterator->chain, iterator->current);
1181         }
1182
1183         iterator->current = save;
1184         return true;
1185 }
1186
1187 FLAC__bool FLAC__metadata_iterator_insert_block_before(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1188 {
1189         FLAC__Metadata_Node *node;
1190
1191         FLAC__ASSERT(0 != iterator);
1192         FLAC__ASSERT(0 != iterator->current);
1193
1194         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1195                 return false;
1196
1197         if(0 == iterator->current->prev) {
1198                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1199                 return false;
1200         }
1201
1202         if(0 == (node = node_new_()))
1203                 return false;
1204
1205         node->data = block;
1206         iterator_insert_node_(iterator, node);
1207         iterator->current = node;
1208         return true;
1209 }
1210
1211 FLAC__bool FLAC__metadata_iterator_insert_block_after(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1212 {
1213         FLAC__Metadata_Node *node;
1214
1215         FLAC__ASSERT(0 != iterator);
1216         FLAC__ASSERT(0 != iterator->current);
1217
1218         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1219                 return false;
1220
1221         if(0 == (node = node_new_()))
1222                 return false;
1223
1224         node->data = block;
1225         iterator_insert_node_after_(iterator, node);
1226         iterator->current = node;
1227         return true;
1228 }
1229
1230
1231 /****************************************************************************
1232  *
1233  * Local function definitions
1234  *
1235  ***************************************************************************/
1236
1237 void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
1238 {
1239         unsigned i;
1240
1241         b += bytes;
1242
1243         for(i = 0; i < bytes; i++) {
1244                 *(--b) = (FLAC__byte)(val & 0xff);
1245                 val >>= 8;
1246         }
1247 }
1248
1249 void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
1250 {
1251         unsigned i;
1252
1253         for(i = 0; i < bytes; i++) {
1254                 *(b++) = (FLAC__byte)(val & 0xff);
1255                 val >>= 8;
1256         }
1257 }
1258
1259 void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes)
1260 {
1261         unsigned i;
1262
1263         b += bytes;
1264
1265         for(i = 0; i < bytes; i++) {
1266                 *(--b) = (FLAC__byte)(val & 0xff);
1267                 val >>= 8;
1268         }
1269 }
1270
1271 FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes)
1272 {
1273         FLAC__uint32 ret = 0;
1274         unsigned i;
1275
1276         for(i = 0; i < bytes; i++)
1277                 ret = (ret << 8) | (FLAC__uint32)(*b++);
1278
1279         return ret;
1280 }
1281
1282 FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes)
1283 {
1284         FLAC__uint32 ret = 0;
1285         unsigned i;
1286
1287         b += bytes;
1288
1289         for(i = 0; i < bytes; i++)
1290                 ret = (ret << 8) | (FLAC__uint32)(*--b);
1291
1292         return ret;
1293 }
1294
1295 FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes)
1296 {
1297         FLAC__uint64 ret = 0;
1298         unsigned i;
1299
1300         for(i = 0; i < bytes; i++)
1301                 ret = (ret << 8) | (FLAC__uint64)(*b++);
1302
1303         return ret;
1304 }
1305
1306 FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator)
1307 {
1308         FLAC__byte raw_header[FLAC__STREAM_METADATA_HEADER_LENGTH];
1309
1310         FLAC__ASSERT(0 != iterator);
1311         FLAC__ASSERT(0 != iterator->file);
1312
1313         if(fread(raw_header, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, iterator->file) != FLAC__STREAM_METADATA_HEADER_LENGTH) {
1314                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1315                 return false;
1316         }
1317
1318         iterator->is_last = raw_header[0] & 0x80? true : false;
1319         iterator->type = (FLAC__MetadataType)(raw_header[0] & 0x7f);
1320         iterator->length = unpack_uint32_(raw_header + 1, 3);
1321
1322         /* do some checking */
1323         if(iterator->type > FLAC__METADATA_TYPE_VORBIS_COMMENT) {
1324                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA;
1325                 return false;
1326         }
1327
1328         return true;
1329 }
1330
1331 FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block)
1332 {
1333         FLAC__ASSERT(0 != iterator);
1334         FLAC__ASSERT(0 != iterator->file);
1335
1336         switch(block->type) {
1337                 case FLAC__METADATA_TYPE_STREAMINFO:
1338                         iterator->status = read_metadata_block_data_streaminfo_(iterator->file, &block->data.stream_info);
1339                         break;
1340                 case FLAC__METADATA_TYPE_PADDING:
1341                         iterator->status = read_metadata_block_data_padding_(iterator->file, &block->data.padding, block->length);
1342                         break;
1343                 case FLAC__METADATA_TYPE_APPLICATION:
1344                         iterator->status = read_metadata_block_data_application_(iterator->file, &block->data.application, block->length);
1345                         break;
1346                 case FLAC__METADATA_TYPE_SEEKTABLE:
1347                         iterator->status = read_metadata_block_data_seektable_(iterator->file, &block->data.seek_table, block->length);
1348                         break;
1349                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
1350                         iterator->status = read_metadata_block_data_vorbis_comment_(iterator->file, &block->data.vorbis_comment);
1351                         break;
1352                 default:
1353                         FLAC__ASSERT(0);
1354                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR;
1355         }
1356
1357         return (iterator->status == FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK);
1358 }
1359
1360 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_(FILE *file, FLAC__StreamMetadata_StreamInfo *block)
1361 {
1362         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH], *b;
1363
1364         FLAC__ASSERT(0 != file);
1365
1366         if(fread(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, file) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
1367                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1368
1369         b = buffer;
1370
1371         /* @@@ we are using hardcoded numbers for simplicity but we should
1372          * probably eventually write a bit-level unpacker and use the
1373          * _STREAMINFO_ constants.
1374          */
1375         block->min_blocksize = unpack_uint32_(b, 2); b += 2;
1376         block->max_blocksize = unpack_uint32_(b, 2); b += 2;
1377         block->min_framesize = unpack_uint32_(b, 3); b += 3;
1378         block->max_framesize = unpack_uint32_(b, 3); b += 3;
1379         block->sample_rate = (unpack_uint32_(b, 2) << 4) | ((unsigned)(b[2] & 0xf0) >> 4);
1380         block->channels = (unsigned)((b[2] & 0x0e) >> 1) + 1;
1381         block->bits_per_sample = ((((unsigned)(b[2] & 0x01)) << 1) | (((unsigned)(b[3] & 0xf0)) >> 4)) + 1;
1382         block->total_samples = (((FLAC__uint64)(b[3] & 0x0f)) << 32) | unpack_uint64_(b+4, 4);
1383         memcpy(block->md5sum, b+8, 16);
1384
1385         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1386 }
1387
1388
1389 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_padding_(FILE *file, FLAC__StreamMetadata_Padding *block, unsigned block_length)
1390 {
1391         FLAC__ASSERT(0 != file);
1392
1393         (void)block; /* nothing to do; we don't care about reading the padding bytes */
1394
1395         if(0 != fseek(file, block_length, SEEK_CUR))
1396                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
1397
1398         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1399 }
1400
1401 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_application_(FILE *file, FLAC__StreamMetadata_Application *block, unsigned block_length)
1402 {
1403         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
1404
1405         FLAC__ASSERT(0 != file);
1406
1407         if(fread(block->id, 1, id_bytes, file) != id_bytes)
1408                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1409
1410         block_length -= id_bytes;
1411
1412         if(block_length == 0) {
1413                 block->data = 0;
1414         }
1415         else {
1416                 if(0 == (block->data = malloc(block_length)))
1417                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
1418
1419                 if(fread(block->data, 1, block_length, file) != block_length)
1420                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1421         }
1422
1423         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1424 }
1425
1426 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_seektable_(FILE *file, FLAC__StreamMetadata_SeekTable *block, unsigned block_length)
1427 {
1428         unsigned i;
1429         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
1430
1431         FLAC__ASSERT(0 != file);
1432         FLAC__ASSERT(block_length % FLAC__STREAM_METADATA_SEEKPOINT_LENGTH == 0);
1433
1434         block->num_points = block_length / FLAC__STREAM_METADATA_SEEKPOINT_LENGTH;
1435
1436         if(block->num_points == 0)
1437                 block->points = 0;
1438         else if(0 == (block->points = malloc(block->num_points * sizeof(FLAC__StreamMetadata_SeekPoint))))
1439                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
1440
1441         for(i = 0; i < block->num_points; i++) {
1442                 if(fread(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, file) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
1443                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1444                 /*@@@ some MAGIC NUMBERs here */
1445                 block->points[i].sample_number = unpack_uint64_(buffer, 8);
1446                 block->points[i].stream_offset = unpack_uint64_(buffer+8, 8);
1447                 block->points[i].frame_samples = unpack_uint32_(buffer+16, 2);
1448         }
1449
1450         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1451 }
1452
1453 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_entry_(FILE *file, FLAC__StreamMetadata_VorbisComment_Entry *entry)
1454 {
1455         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
1456         FLAC__byte buffer[4]; /* magic number is asserted below */
1457
1458         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8 == 4);
1459         FLAC__ASSERT(0 != file);
1460
1461         if(fread(buffer, 1, entry_length_len, file) != entry_length_len)
1462                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1463         entry->length = unpack_uint32_little_endian_(buffer, entry_length_len);
1464
1465         if(entry->length == 0) {
1466                 entry->entry = 0;
1467         }
1468         else {
1469                 if(0 == (entry->entry = malloc(entry->length)))
1470                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
1471
1472                 if(fread(entry->entry, 1, entry->length, file) != entry->length)
1473                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1474         }
1475
1476         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1477 }
1478
1479 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_(FILE *file, FLAC__StreamMetadata_VorbisComment *block)
1480 {
1481         unsigned i;
1482         FLAC__Metadata_SimpleIteratorStatus status;
1483         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
1484         FLAC__byte buffer[4]; /* magic number is asserted below */
1485
1486         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8 == 4);
1487         FLAC__ASSERT(0 != file);
1488
1489         if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_(file, &(block->vendor_string))))
1490                 return status;
1491
1492         if(fread(buffer, 1, num_comments_len, file) != num_comments_len)
1493                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1494         block->num_comments = unpack_uint32_little_endian_(buffer, num_comments_len);
1495
1496         if(block->num_comments == 0) {
1497                 block->comments = 0;
1498         }
1499         else if(0 == (block->comments = malloc(block->num_comments * sizeof(FLAC__StreamMetadata_VorbisComment_Entry))))
1500                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
1501
1502         for(i = 0; i < block->num_comments; i++) {
1503                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_(file, block->comments + i)))
1504                         return status;
1505         }
1506
1507         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1508 }
1509
1510 FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
1511 {
1512         FLAC__byte buffer[FLAC__STREAM_METADATA_HEADER_LENGTH];
1513
1514         FLAC__ASSERT(0 != file);
1515         FLAC__ASSERT(0 != status);
1516         FLAC__ASSERT(block->length < (1u << FLAC__STREAM_METADATA_LENGTH_LEN));
1517
1518         buffer[0] = (block->is_last? 0x80 : 0) | (FLAC__byte)block->type;
1519         pack_uint32_(block->length, buffer + 1, 3);
1520
1521         if(fwrite(buffer, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, file) != FLAC__STREAM_METADATA_HEADER_LENGTH) {
1522                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1523                 return false;
1524         }
1525
1526         return true;
1527 }
1528
1529 FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
1530 {
1531         FLAC__ASSERT(0 != file);
1532         FLAC__ASSERT(0 != status);
1533
1534         switch(block->type) {
1535                 case FLAC__METADATA_TYPE_STREAMINFO:
1536                         *status = write_metadata_block_data_streaminfo_(file, &block->data.stream_info);
1537                         break;
1538                 case FLAC__METADATA_TYPE_PADDING:
1539                         *status = write_metadata_block_data_padding_(file, &block->data.padding, block->length);
1540                         break;
1541                 case FLAC__METADATA_TYPE_APPLICATION:
1542                         *status = write_metadata_block_data_application_(file, &block->data.application, block->length);
1543                         break;
1544                 case FLAC__METADATA_TYPE_SEEKTABLE:
1545                         *status = write_metadata_block_data_seektable_(file, &block->data.seek_table);
1546                         break;
1547                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
1548                         *status = write_metadata_block_data_vorbis_comment_(file, &block->data.vorbis_comment);
1549                         break;
1550                 default:
1551                         FLAC__ASSERT(0);
1552                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR;
1553         }
1554         return (*status == FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK);
1555 }
1556
1557 FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_streaminfo_(FILE *file, const FLAC__StreamMetadata_StreamInfo *block)
1558 {
1559         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH];
1560         const unsigned channels1 = block->channels - 1;
1561         const unsigned bps1 = block->bits_per_sample - 1;
1562
1563         FLAC__ASSERT(0 != file);
1564
1565         /* @@@ we are using hardcoded numbers for simplicity but we should
1566          * probably eventually write a bit-level packer and use the
1567          * _STREAMINFO_ constants.
1568          */
1569         pack_uint32_(block->min_blocksize, buffer, 2);
1570         pack_uint32_(block->max_blocksize, buffer+2, 2);
1571         pack_uint32_(block->min_framesize, buffer+4, 3);
1572         pack_uint32_(block->max_framesize, buffer+7, 3);
1573         buffer[10] = (block->sample_rate >> 12) & 0xff;
1574         buffer[11] = (block->sample_rate >> 4) & 0xff;
1575         buffer[12] = ((block->sample_rate & 0x0f) << 4) | (channels1 << 1) | (bps1 >> 4);
1576         buffer[13] = (FLAC__byte)(((bps1 & 0x0f) << 4) | ((block->total_samples >> 32) & 0x0f));
1577         pack_uint32_((FLAC__uint32)block->total_samples, buffer+14, 4);
1578         memcpy(buffer+18, block->md5sum, 16);
1579
1580         if(fwrite(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, file) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
1581                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1582
1583         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1584 }
1585
1586 FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_padding_(FILE *file, const FLAC__StreamMetadata_Padding *block, unsigned block_length)
1587 {
1588         unsigned i, n = block_length;
1589         FLAC__byte buffer[1024];
1590
1591         FLAC__ASSERT(0 != file);
1592
1593         (void)block;
1594
1595         memset(buffer, 0, 1024);
1596
1597         for(i = 0; i < n/1024; i++)
1598                 if(fwrite(buffer, 1, 1024, file) != 1024)
1599                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1600
1601         n %= 1024;
1602
1603         if(fwrite(buffer, 1, n, file) != n)
1604                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1605
1606         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1607 }
1608
1609 FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_application_(FILE *file, const FLAC__StreamMetadata_Application *block, unsigned block_length)
1610 {
1611         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
1612
1613         FLAC__ASSERT(0 != file);
1614
1615         if(fwrite(block->id, 1, id_bytes, file) != id_bytes)
1616                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1617
1618         block_length -= id_bytes;
1619
1620         if(fwrite(block->data, 1, block_length, file) != block_length)
1621                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1622
1623         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1624 }
1625
1626 FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_seektable_(FILE *file, const FLAC__StreamMetadata_SeekTable *block)
1627 {
1628         unsigned i;
1629         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
1630
1631         FLAC__ASSERT(0 != file);
1632
1633         for(i = 0; i < block->num_points; i++) {
1634                 /*@@@ some MAGIC NUMBERs here */
1635                 pack_uint64_(block->points[i].sample_number, buffer, 8);
1636                 pack_uint64_(block->points[i].stream_offset, buffer+8, 8);
1637                 pack_uint32_(block->points[i].frame_samples, buffer+16, 2);
1638                 if(fwrite(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, file) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
1639                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1640         }
1641
1642         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1643 }
1644
1645 FLAC__Metadata_SimpleIteratorStatus write_metadata_block_data_vorbis_comment_(FILE *file, const FLAC__StreamMetadata_VorbisComment *block)
1646 {
1647         unsigned i;
1648         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
1649         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
1650         FLAC__byte buffer[4]; /* magic number is asserted below */
1651
1652         FLAC__ASSERT(max(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN, FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN) / 8 == 4);
1653         FLAC__ASSERT(0 != file);
1654
1655         pack_uint32_little_endian_(block->vendor_string.length, buffer, entry_length_len);
1656         if(fwrite(buffer, 1, entry_length_len, file) != entry_length_len)
1657                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1658         if(fwrite(block->vendor_string.entry, 1, block->vendor_string.length, file) != block->vendor_string.length)
1659                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1660
1661         pack_uint32_little_endian_(block->num_comments, buffer, num_comments_len);
1662         if(fwrite(buffer, 1, num_comments_len, file) != num_comments_len)
1663                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1664
1665         for(i = 0; i < block->num_comments; i++) {
1666                 pack_uint32_little_endian_(block->comments[i].length, buffer, entry_length_len);
1667                 if(fwrite(buffer, 1, entry_length_len, file) != entry_length_len)
1668                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1669                 if(fwrite(block->comments[i].entry, 1, block->comments[i].length, file) != block->comments[i].length)
1670                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
1671         }
1672
1673         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1674 }
1675
1676 FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block)
1677 {
1678         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
1679                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
1680                 return false;
1681         }
1682
1683         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
1684                 return false;
1685
1686         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
1687                 return false;
1688
1689         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
1690                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
1691                 return false;
1692         }
1693
1694         return read_metadata_block_header_(iterator);
1695 }
1696
1697 FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last)
1698 {
1699         FLAC__StreamMetadata *padding;
1700
1701         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
1702                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
1703                 return false;
1704         }
1705
1706         block->is_last = false;
1707
1708         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
1709                 return false;
1710
1711         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
1712                 return false;
1713
1714         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING)))
1715                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
1716
1717         padding->is_last = padding_is_last;
1718         padding->length = padding_length;
1719
1720         if(!write_metadata_block_header_(iterator->file, &iterator->status, padding)) {
1721                 FLAC__metadata_object_delete(padding);
1722                 return false;
1723         }
1724
1725         if(!write_metadata_block_data_(iterator->file, &iterator->status, padding)) {
1726                 FLAC__metadata_object_delete(padding);
1727                 return false;
1728         }
1729
1730         FLAC__metadata_object_delete(padding);
1731
1732         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
1733                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
1734                 return false;
1735         }
1736
1737         return read_metadata_block_header_(iterator);
1738 }
1739
1740 FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append)
1741 {
1742         FILE *tempfile;
1743         char *tempfilename;
1744         int fixup_is_last_code = 0; /* 0 => no need to change any is_last flags */
1745         long fixup_is_last_flag_offset = -1;
1746
1747         FLAC__ASSERT(0 != block || append == false);
1748
1749         if(iterator->is_last) {
1750                 if(append) {
1751                         fixup_is_last_code = 1; /* 1 => clear the is_last flag at the following offset */
1752                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
1753                 }
1754                 else if(0 == block) {
1755                         simple_iterator_push_(iterator);
1756                         if(!FLAC__metadata_simple_iterator_prev(iterator)) {
1757                                 (void)simple_iterator_pop_(iterator);
1758                                 return false;
1759                         }
1760                         fixup_is_last_code = -1; /* -1 => set the is_last the flag at the following offset */
1761                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
1762                         if(!simple_iterator_pop_(iterator))
1763                                 return false;
1764                 }
1765         }
1766
1767         if(!simple_iterator_copy_file_prefix_(iterator, &tempfile, &tempfilename, append))
1768                 return false;
1769
1770         if(0 != block) {
1771                 if(!write_metadata_block_header_(tempfile, &iterator->status, block)) {
1772                         cleanup_tempfile_(&tempfile, &tempfilename);
1773                         return false;
1774                 }
1775
1776                 if(!write_metadata_block_data_(tempfile, &iterator->status, block)) {
1777                         cleanup_tempfile_(&tempfile, &tempfilename);
1778                         return false;
1779                 }
1780         }
1781
1782         if(!simple_iterator_copy_file_postfix_(iterator, &tempfile, &tempfilename, fixup_is_last_code, fixup_is_last_flag_offset, block==0))
1783                 return false;
1784
1785         if(append)
1786                 return FLAC__metadata_simple_iterator_next(iterator);
1787
1788         return true;
1789 }
1790
1791 FLAC__bool chain_rewrite_chain_(FLAC__Metadata_Chain *chain)
1792 {
1793         FILE *f;
1794         FLAC__Metadata_Node *node;
1795         FLAC__Metadata_SimpleIteratorStatus status;
1796
1797         FLAC__ASSERT(0 != chain);
1798         FLAC__ASSERT(0 != chain->filename);
1799         FLAC__ASSERT(0 != chain->head);
1800
1801         if(0 == (f = fopen(chain->filename, "r+b"))) {
1802                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1803                 return false;
1804         }
1805         if(0 != fseek(f, chain->first_offset, SEEK_SET)) {
1806                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1807                 return false;
1808         }
1809
1810         for(node = chain->head; node; node = node->next) {
1811                 if(!write_metadata_block_header_(f, &status, node->data)) {
1812                         chain->status = get_equivalent_status_(status);
1813                         return false;
1814                 }
1815                 if(!write_metadata_block_data_(f, &status, node->data)) {
1816                         chain->status = get_equivalent_status_(status);
1817                         return false;
1818                 }
1819         }
1820
1821         /*FLAC__ASSERT(fflush(), ftell() == chain->last_offset);*/
1822
1823         (void)fclose(f);
1824
1825         return true;
1826 }
1827
1828 FLAC__bool chain_rewrite_file_(FLAC__Metadata_Chain *chain, const char *tempfile_path_prefix)
1829 {
1830         FILE *f, *tempfile;
1831         char *tempfilename;
1832         FLAC__Metadata_SimpleIteratorStatus status;
1833         const FLAC__Metadata_Node *node;
1834
1835         FLAC__ASSERT(0 != chain);
1836         FLAC__ASSERT(0 != chain->filename);
1837         FLAC__ASSERT(0 != chain->head);
1838
1839         /* copy the file prefix (data up to first metadata block */
1840         if(0 == (f = fopen(chain->filename, "rb"))) {
1841                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1842                 return false;
1843         }
1844         if(!open_tempfile_(chain->filename, tempfile_path_prefix, &tempfile, &tempfilename, &status)) {
1845                 chain->status = get_equivalent_status_(status);
1846                 cleanup_tempfile_(&tempfile, &tempfilename);
1847                 return false;
1848         }
1849         if(!copy_n_bytes_from_file_(f, tempfile, chain->first_offset, &status)) {
1850                 chain->status = get_equivalent_status_(status);
1851                 cleanup_tempfile_(&tempfile, &tempfilename);
1852                 return false;
1853         }
1854
1855         /* write the metadata */
1856         for(node = chain->head; node; node = node->next) {
1857                 if(!write_metadata_block_header_(tempfile, &status, node->data)) {
1858                         chain->status = get_equivalent_status_(status);
1859                         return false;
1860                 }
1861                 if(!write_metadata_block_data_(tempfile, &status, node->data)) {
1862                         chain->status = get_equivalent_status_(status);
1863                         return false;
1864                 }
1865         }
1866         /*FLAC__ASSERT(fflush(), ftell() == chain->last_offset);*/
1867
1868         /* copy the file postfix (everything after the metadata) */
1869         if(0 != fseek(f, chain->last_offset, SEEK_SET)) {
1870                 cleanup_tempfile_(&tempfile, &tempfilename);
1871                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1872                 return false;
1873         }
1874         if(!copy_remaining_bytes_from_file_(f, tempfile, &status)) {
1875                 cleanup_tempfile_(&tempfile, &tempfilename);
1876                 chain->status = get_equivalent_status_(status);
1877                 return false;
1878         }
1879
1880         /* move the tempfile on top of the original */
1881         (void)fclose(f);
1882         if(!transport_tempfile_(chain->filename, &tempfile, &tempfilename, &status))
1883                 return false;
1884
1885         return true;
1886 }
1887
1888 void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator)
1889 {
1890         FLAC__ASSERT(iterator->depth+1 < SIMPLE_ITERATOR_MAX_PUSH_DEPTH);
1891         iterator->offset[iterator->depth+1] = iterator->offset[iterator->depth];
1892         iterator->depth++;
1893 }
1894
1895 FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator)
1896 {
1897         FLAC__ASSERT(iterator->depth > 0);
1898         iterator->depth--;
1899         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
1900                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
1901                 return false;
1902         }
1903
1904         return read_metadata_block_header_(iterator);
1905 }
1906
1907 unsigned seek_to_first_metadata_block_(FILE *f)
1908 {
1909         FLAC__byte buffer[4];
1910         size_t n;
1911         unsigned i;
1912
1913         FLAC__ASSERT(0 != f);
1914         FLAC__ASSERT(FLAC__STREAM_SYNC_LENGTH == 4);
1915
1916         /* skip any id3v2 tag */
1917 #if !defined _MSC_VER && !defined __MINGW32__
1918 /*@@@ don't know how to resolve errno without using LIBC.LIB; must use MSVCRT.LIB only for plugins */
1919         errno = 0;
1920 #endif
1921         n = fread(buffer, 1, 4, f);
1922 #if !defined _MSC_VER && !defined __MINGW32__
1923 /*@@@ don't know how to resolve errno without using LIBC.LIB; must use MSVCRT.LIB only for plugins */
1924         if(errno)
1925                 return 1;
1926         else
1927 #endif
1928         if(n != 4)
1929                 return 2;
1930         else if(0 == memcmp(buffer, "ID3", 3)) {
1931                 unsigned tag_length = 0;
1932
1933                 /* skip to the tag length */
1934                 if(fseek(f, 2, SEEK_CUR) < 0)
1935                         return 1;
1936
1937                 /* read the length */
1938                 for(i = 0; i < 4; i++) {
1939                         if(fread(buffer, 1, 1, f) < 1 || buffer[0] & 0x80)
1940                                 return 1;
1941                         tag_length <<= 7;
1942                         tag_length |= (buffer[0] & 0x7f);
1943                 }
1944
1945                 /* skip the rest of the tag */
1946                 if(fseek(f, tag_length, SEEK_CUR) < 0)
1947                         return 1;
1948
1949                 /* read the stream sync code */
1950 #if !defined _MSC_VER && !defined __MINGW32__
1951 /*@@@ don't know how to resolve errno without using LIBC.LIB; must use MSVCRT.LIB only for plugins */
1952                 errno = 0;
1953 #endif
1954                 n = fread(buffer, 1, 4, f);
1955 #if !defined _MSC_VER && !defined __MINGW32__
1956 /*@@@ don't know how to resolve errno without using LIBC.LIB; must use MSVCRT.LIB only for plugins */
1957                 if(errno)
1958                         return 1;
1959                 else
1960 #endif
1961                 if(n != 4)
1962                         return 2;
1963         }
1964
1965         /* check for the fLaC signature */
1966         if(0 == memcmp(FLAC__STREAM_SYNC_STRING, buffer, FLAC__STREAM_SYNC_LENGTH))
1967                 return 0;
1968         else
1969                 return 2;
1970 }
1971
1972 FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append)
1973 {
1974         const long offset_end = append? iterator->offset[iterator->depth] + (long)FLAC__STREAM_METADATA_HEADER_LENGTH + (long)iterator->length : iterator->offset[iterator->depth];
1975
1976         if(0 != fseek(iterator->file, 0, SEEK_SET)) {
1977                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
1978                 return false;
1979         }
1980         if(!open_tempfile_(iterator->filename, iterator->tempfile_path_prefix, tempfile, tempfilename, &iterator->status)) {
1981                 cleanup_tempfile_(tempfile, tempfilename);
1982                 return false;
1983         }
1984         if(!copy_n_bytes_from_file_(iterator->file, *tempfile, offset_end, &iterator->status)) {
1985                 cleanup_tempfile_(tempfile, tempfilename);
1986                 return false;
1987         }
1988
1989         return true;
1990 }
1991
1992 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)
1993 {
1994         long save_offset = iterator->offset[iterator->depth]; /*@@@ 2G limit */
1995         FLAC__ASSERT(0 != *tempfile);
1996
1997         if(0 != fseek(iterator->file, save_offset + FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length, SEEK_SET)) {
1998                 cleanup_tempfile_(tempfile, tempfilename);
1999                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2000                 return false;
2001         }
2002         if(!copy_remaining_bytes_from_file_(iterator->file, *tempfile, &iterator->status)) {
2003                 cleanup_tempfile_(tempfile, tempfilename);
2004                 return false;
2005         }
2006
2007         if(fixup_is_last_code != 0) {
2008                 /*
2009                  * if code == 1, it means a block was appended to the end so
2010                  *   we have to clear the is_last flag of the previous block
2011                  * if code == -1, it means the last block was deleted so
2012                  *   we have to set the is_last flag of the previous block
2013                  */
2014                 /*@@@ MAGIC NUMBERs here; we know the is_last flag is the high bit of the byte at this location */
2015                 FLAC__byte x;
2016                 if(0 != fseek(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
2017                         cleanup_tempfile_(tempfile, tempfilename);
2018                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2019                         return false;
2020                 }
2021                 if(fread(&x, 1, 1, *tempfile) != 1) {
2022                         cleanup_tempfile_(tempfile, tempfilename);
2023                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2024                         return false;
2025                 }
2026                 if(fixup_is_last_code > 0) {
2027                         FLAC__ASSERT(x & 0x80);
2028                         x &= 0x7f;
2029                 }
2030                 else {
2031                         FLAC__ASSERT(!(x & 0x80));
2032                         x |= 0x80;
2033                 }
2034                 if(0 != fseek(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
2035                         cleanup_tempfile_(tempfile, tempfilename);
2036                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2037                         return false;
2038                 }
2039                 if(fwrite(&x, 1, 1, *tempfile) != 1) {
2040                         cleanup_tempfile_(tempfile, tempfilename);
2041                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2042                         return false;
2043                 }
2044         }
2045
2046         (void)fclose(iterator->file);
2047
2048         if(!transport_tempfile_(iterator->filename, tempfile, tempfilename, &iterator->status))
2049                 return false;
2050
2051         if(iterator->has_stats)
2052                 set_file_stats_(iterator->filename, &iterator->stats);
2053
2054         if(!simple_iterator_prime_input_(iterator))
2055                 return false;
2056         if(backup) {
2057                 while(iterator->offset[iterator->depth] + (long)FLAC__STREAM_METADATA_HEADER_LENGTH + (long)iterator->length < save_offset)
2058                         if(!FLAC__metadata_simple_iterator_next(iterator))
2059                                 return false;
2060                 return true;
2061         }
2062         else {
2063                 /* move the iterator to it's original block faster by faking a push, then doing a pop_ */
2064                 FLAC__ASSERT(iterator->depth == 0);
2065                 iterator->offset[0] = save_offset;
2066                 iterator->depth++;
2067                 return simple_iterator_pop_(iterator);
2068         }
2069 }
2070
2071 FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, unsigned bytes/*@@@ 4G limit*/, FLAC__Metadata_SimpleIteratorStatus *status)
2072 {
2073         FLAC__byte buffer[8192];
2074         unsigned n;
2075
2076         while(bytes > 0) {
2077                 n = min(sizeof(buffer), bytes);
2078                 if(fread(buffer, 1, n, file) != n) {
2079                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2080                         return false;
2081                 }
2082                 if(fwrite(buffer, 1, n, tempfile) != n) {
2083                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2084                         return false;
2085                 }
2086                 bytes -= n;
2087         }
2088
2089         return true;
2090 }
2091
2092 FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status)
2093 {
2094         FLAC__byte buffer[8192];
2095         size_t n;
2096
2097         while(!feof(file)) {
2098                 n = fread(buffer, 1, sizeof(buffer), file);
2099                 if(n == 0 && !feof(file)) {
2100                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2101                         return false;
2102                 }
2103                 if(n > 0 && fwrite(buffer, 1, n, tempfile) != n) {
2104                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2105                         return false;
2106                 }
2107         }
2108
2109         return true;
2110 }
2111
2112 FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
2113 {
2114         static const char *tempfile_suffix = ".metadata_edit";
2115         if(0 == tempfile_path_prefix) {
2116                 if(0 == (*tempfilename = malloc(strlen(filename) + strlen(tempfile_suffix) + 1))) {
2117                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2118                         return false;
2119                 }
2120                 strcpy(*tempfilename, filename);
2121                 strcat(*tempfilename, tempfile_suffix);
2122         }
2123         else {
2124                 const char *p = strrchr(filename, '/');
2125                 if(0 == p)
2126                         p = filename;
2127                 else
2128                         p++;
2129
2130                 if(0 == (*tempfilename = malloc(strlen(tempfile_path_prefix) + 1 + strlen(p) + strlen(tempfile_suffix) + 1))) {
2131                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2132                         return false;
2133                 }
2134                 strcpy(*tempfilename, tempfile_path_prefix);
2135                 strcat(*tempfilename, "/");
2136                 strcat(*tempfilename, p);
2137                 strcat(*tempfilename, tempfile_suffix);
2138         }
2139
2140         if(0 == (*tempfile = fopen(*tempfilename, "w+b"))) {
2141                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
2142                 return false;
2143         }
2144
2145         return true;
2146 }
2147
2148 FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
2149 {
2150         FLAC__ASSERT(0 != filename);
2151         FLAC__ASSERT(0 != tempfile);
2152         FLAC__ASSERT(0 != *tempfile);
2153         FLAC__ASSERT(0 != tempfilename);
2154         FLAC__ASSERT(0 != *tempfilename);
2155         FLAC__ASSERT(0 != status);
2156
2157         (void)fclose(*tempfile);
2158         *tempfile = 0;
2159
2160 #if defined _MSC_VER || defined __MINGW32__
2161         if(unlink(filename) < 0) {
2162                 cleanup_tempfile_(tempfile, tempfilename);
2163                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR;
2164                 return false;
2165         }
2166 #endif
2167
2168         /*@@@ to fully support the tempfile_path_prefix we need to update this piece to actually copy across filesystems instead of just rename(): */
2169         if(0 != rename(*tempfilename, filename)) {
2170                 cleanup_tempfile_(tempfile, tempfilename);
2171                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR;
2172                 return false;
2173         }
2174
2175         cleanup_tempfile_(tempfile, tempfilename);
2176
2177         return true;
2178 }
2179
2180 void cleanup_tempfile_(FILE **tempfile, char **tempfilename)
2181 {
2182         if(0 != *tempfile) {
2183                 (void)fclose(*tempfile);
2184                 *tempfile = 0;
2185         }
2186
2187         if(0 != *tempfilename) {
2188                 (void)unlink(*tempfilename);
2189                 free(*tempfilename);
2190                 *tempfilename = 0;
2191         }
2192 }
2193
2194 FLAC__bool get_file_stats_(const char *filename, struct stat *stats)
2195 {
2196         FLAC__ASSERT(0 != filename);
2197         FLAC__ASSERT(0 != stats);
2198         return (0 == stat(filename, stats));
2199 }
2200
2201 void set_file_stats_(const char *filename, struct stat *stats)
2202 {
2203         struct utimbuf srctime;
2204
2205         FLAC__ASSERT(0 != filename);
2206         FLAC__ASSERT(0 != stats);
2207
2208         srctime.actime = stats->st_atime;
2209         srctime.modtime = stats->st_mtime;
2210         (void)chmod(filename, stats->st_mode);
2211         (void)utime(filename, &srctime);
2212 #if !defined _MSC_VER && !defined __MINGW32__
2213         (void)chown(filename, stats->st_uid, -1);
2214         (void)chown(filename, -1, stats->st_gid);
2215 #endif
2216 }
2217
2218 FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status)
2219 {
2220         switch(status) {
2221                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK:
2222                         return FLAC__METADATA_CHAIN_STATUS_OK;
2223                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT:
2224                         return FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT;
2225                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE:
2226                         return FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
2227                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE:
2228                         return FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE;
2229                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE:
2230                         return FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE;
2231                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA:
2232                         return FLAC__METADATA_CHAIN_STATUS_BAD_METADATA;
2233                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR:
2234                         return FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
2235                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR:
2236                         return FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
2237                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR:
2238                         return FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
2239                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR:
2240                         return FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR;
2241                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR:
2242                         return FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR;
2243                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR:
2244                         return FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
2245                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR:
2246                 default:
2247                         return FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
2248         }
2249 }