src/libFLAC/metadata_iterators.c

   1 /* libFLAC - Free Lossless Audio Codec library
   2  * Copyright (C) 2001,2002,2003,2004  Josh Coalson
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  * - Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *
  11  * - Redistributions in binary form must reproduce the above copyright
  12  * notice, this list of conditions and the following disclaimer in the
  13  * documentation and/or other materials provided with the distribution.
  14  *
  15  * - Neither the name of the Xiph.org Foundation nor the names of its
  16  * contributors may be used to endorse or promote products derived from
  17  * this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  22  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
  23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  26  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  27  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  28  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  29  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 #include <errno.h>
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <string.h>
  36
  37 #if defined _MSC_VER || defined __MINGW32__
  38 #include <sys/utime.h> /* for utime() */
  39 #include <io.h> /* for chmod() */
  40 #else
  41 #include <sys/types.h> /* some flavors of BSD (like OS X) require this to get time_t */
  42 #include <utime.h> /* for utime() */
  43 #include <unistd.h> /* for chown(), unlink() */
  44 #endif
  45 #include <sys/stat.h> /* for stat(), maybe chmod() */
  46
  47 #include "private/metadata.h"
  48
  49 #include "FLAC/assert.h"
  50 #include "FLAC/file_decoder.h"
  51
  52 #ifdef max
  53 #undef max
  54 #endif
  55 #define max(a,b) ((a)>(b)?(a):(b))
  56 #ifdef min
  57 #undef min
  58 #endif
  59 #define min(a,b) ((a)<(b)?(a):(b))
  60
  61
  62 /****************************************************************************
  63  *
  64  * Local function declarations
  65  *
  66  ***************************************************************************/
  67
  68 static void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes);
  69 static void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes);
  70 static void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes);
  71 static FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes);
  72 static FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes);
  73 static FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes);
  74
  75 static FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator);
  76 static FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block);
  77 static FLAC__bool read_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__bool *is_last, FLAC__MetadataType *type, unsigned *length);
  78 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata *block);
  79 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_StreamInfo *block);
  80 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata_Padding *block, unsigned block_length);
  81 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Application *block, unsigned block_length);
  82 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_SeekTable *block, unsigned block_length);
  83 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_entry_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment_Entry *entry);
  84 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment *block);
  85 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet_Track *track);
  86 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet *block);
  87 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Unknown *block, unsigned block_length);
  88
  89 static FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block);
  90 static FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block);
  91 static FLAC__bool write_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block);
  92 static FLAC__bool write_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block);
  93 static FLAC__bool write_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_StreamInfo *block);
  94 static FLAC__bool write_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Padding *block, unsigned block_length);
  95 static FLAC__bool write_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Application *block, unsigned block_length);
  96 static FLAC__bool write_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_SeekTable *block);
  97 static FLAC__bool write_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_VorbisComment *block);
  98 static FLAC__bool write_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_CueSheet *block);
  99 static FLAC__bool write_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Unknown *block, unsigned block_length);
 100
 101 static FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block);
 102 static FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last);
 103 static FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append);
 104
 105 static void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator);
 106 static FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator);
 107
 108 static unsigned seek_to_first_metadata_block_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb);
 109 static unsigned seek_to_first_metadata_block_(FILE *f);
 110
 111 static FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append);
 112 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);
 113
 114 static FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, unsigned bytes/*@@@ 4G limit*/, FLAC__Metadata_SimpleIteratorStatus *status);
 115 static FLAC__bool copy_n_bytes_from_file_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOHandle temp_handle, FLAC__IOCallback_Write temp_write_cb, unsigned bytes/*@@@ 4G limit*/, FLAC__Metadata_SimpleIteratorStatus *status);
 116 static FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status);
 117 static FLAC__bool copy_remaining_bytes_from_file_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Eof eof_cb, FLAC__IOHandle temp_handle, FLAC__IOCallback_Write temp_write_cb, FLAC__Metadata_SimpleIteratorStatus *status);
 118
 119 static FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status);
 120 static FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status);
 121 static void cleanup_tempfile_(FILE **tempfile, char **tempfilename);
 122
 123 static FLAC__bool get_file_stats_(const char *filename, struct stat *stats);
 124 static void set_file_stats_(const char *filename, struct stat *stats);
 125
 126 static int fseek_wrapper_(FLAC__IOHandle handle, FLAC__int64 offset, int whence);
 127 static FLAC__int64 ftell_wrapper_(FLAC__IOHandle handle);
 128
 129 static FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status);
 130
 131
 132 #ifdef FLAC__VALGRIND_TESTING
 133 static size_t local__fwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream)
 134 {
 135         size_t ret = fwrite(ptr, size, nmemb, stream);
 136         if(!ferror(stream))
 137                 fflush(stream);
 138         return ret;
 139 }
 140 #else
 141 #define local__fwrite fwrite
 142 #endif
 143
 144 /****************************************************************************
 145  *
 146  * Level 0 implementation
 147  *
 148  ***************************************************************************/
 149
 150 static FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__FileDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data);
 151 static void metadata_callback_(const FLAC__FileDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data);
 152 static void error_callback_(const FLAC__FileDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data);
 153
 154 typedef struct {
 155         FLAC__bool got_error;
 156         FLAC__bool got_object;
 157         FLAC__StreamMetadata *object;
 158 } level0_client_data;
 159
 160 FLAC_API FLAC__bool FLAC__metadata_get_streaminfo(const char *filename, FLAC__StreamMetadata *streaminfo)
 161 {
 162         level0_client_data cd;
 163         FLAC__FileDecoder *decoder;
 164
 165         FLAC__ASSERT(0 != filename);
 166         FLAC__ASSERT(0 != streaminfo);
 167
 168         decoder = FLAC__file_decoder_new();
 169
 170         if(0 == decoder)
 171                 return false;
 172
 173         cd.got_error = false;
 174         cd.got_object = false;
 175         cd.object = 0;
 176
 177         FLAC__file_decoder_set_md5_checking(decoder, false);
 178         FLAC__file_decoder_set_filename(decoder, filename);
 179         FLAC__file_decoder_set_metadata_ignore_all(decoder);
 180         FLAC__file_decoder_set_metadata_respond(decoder, FLAC__METADATA_TYPE_STREAMINFO);
 181         FLAC__file_decoder_set_write_callback(decoder, write_callback_);
 182         FLAC__file_decoder_set_metadata_callback(decoder, metadata_callback_);
 183         FLAC__file_decoder_set_error_callback(decoder, error_callback_);
 184         FLAC__file_decoder_set_client_data(decoder, &cd);
 185
 186         if(FLAC__file_decoder_init(decoder) != FLAC__FILE_DECODER_OK || cd.got_error) {
 187                 FLAC__file_decoder_finish(decoder);
 188                 FLAC__file_decoder_delete(decoder);
 189                 return false;
 190         }
 191
 192         if(!FLAC__file_decoder_process_until_end_of_metadata(decoder) || cd.got_error) {
 193                 FLAC__file_decoder_finish(decoder);
 194                 FLAC__file_decoder_delete(decoder);
 195                 if(0 != cd.object)
 196                         FLAC__metadata_object_delete(cd.object);
 197                 return false;
 198         }
 199
 200         FLAC__file_decoder_finish(decoder);
 201         FLAC__file_decoder_delete(decoder);
 202
 203         if(cd.got_object) {
 204                 /* can just copy the contents since STREAMINFO has no internal structure */
 205                 *streaminfo = *(cd.object);
 206         }
 207
 208         if(0 != cd.object)
 209                 FLAC__metadata_object_delete(cd.object);
 210
 211         return cd.got_object;
 212 }
 213
 214 FLAC_API FLAC__bool FLAC__metadata_get_tags(const char *filename, FLAC__StreamMetadata **tags)
 215 {
 216         level0_client_data cd;
 217         FLAC__FileDecoder *decoder;
 218
 219         FLAC__ASSERT(0 != filename);
 220         FLAC__ASSERT(0 != tags);
 221
 222         decoder = FLAC__file_decoder_new();
 223
 224         if(0 == decoder)
 225                 return false;
 226
 227         *tags = 0;
 228
 229         cd.got_error = false;
 230         cd.got_object = false;
 231         cd.object = 0;
 232
 233         FLAC__file_decoder_set_md5_checking(decoder, false);
 234         FLAC__file_decoder_set_filename(decoder, filename);
 235         FLAC__file_decoder_set_metadata_ignore_all(decoder);
 236         FLAC__file_decoder_set_metadata_respond(decoder, FLAC__METADATA_TYPE_VORBIS_COMMENT);
 237         FLAC__file_decoder_set_write_callback(decoder, write_callback_);
 238         FLAC__file_decoder_set_metadata_callback(decoder, metadata_callback_);
 239         FLAC__file_decoder_set_error_callback(decoder, error_callback_);
 240         FLAC__file_decoder_set_client_data(decoder, &cd);
 241
 242         if(FLAC__file_decoder_init(decoder) != FLAC__FILE_DECODER_OK || cd.got_error) {
 243                 FLAC__file_decoder_finish(decoder);
 244                 FLAC__file_decoder_delete(decoder);
 245                 return false;
 246         }
 247
 248         if(!FLAC__file_decoder_process_until_end_of_metadata(decoder) || cd.got_error) {
 249                 FLAC__file_decoder_finish(decoder);
 250                 FLAC__file_decoder_delete(decoder);
 251                 if(0 != cd.object)
 252                         FLAC__metadata_object_delete(cd.object);
 253                 return false;
 254         }
 255
 256         FLAC__file_decoder_finish(decoder);
 257         FLAC__file_decoder_delete(decoder);
 258
 259         if(cd.got_object)
 260                 *tags = cd.object;
 261
 262         return cd.got_object;
 263 }
 264
 265 FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__FileDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
 266 {
 267         (void)decoder, (void)frame, (void)buffer, (void)client_data;
 268
 269         return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;
 270 }
 271
 272 void metadata_callback_(const FLAC__FileDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
 273 {
 274         level0_client_data *cd = (level0_client_data *)client_data;
 275         (void)decoder;
 276
 277         /*
 278          * we assume we only get here when the one metadata block we were
 279          * looking for was passed to us
 280          */
 281         if(!cd->got_object) {
 282                 if(0 == (cd->object = FLAC__metadata_object_clone(metadata)))
 283                         cd->got_error = true;
 284                 else
 285                         cd->got_object = true;
 286         }
 287 }
 288
 289 void error_callback_(const FLAC__FileDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
 290 {
 291         level0_client_data *cd = (level0_client_data *)client_data;
 292         (void)decoder;
 293
 294         if(status != FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC)
 295                 cd->got_error = true;
 296 }
 297
 298
 299 /****************************************************************************
 300  *
 301  * Level 1 implementation
 302  *
 303  ***************************************************************************/
 304
 305 #define SIMPLE_ITERATOR_MAX_PUSH_DEPTH (1+4)
 306 /* 1 for initial offset, +4 for our own personal use */
 307
 308 struct FLAC__Metadata_SimpleIterator {
 309         FILE *file;
 310         char *filename, *tempfile_path_prefix;
 311         struct stat stats;
 312         FLAC__bool has_stats;
 313         FLAC__bool is_writable;
 314         FLAC__Metadata_SimpleIteratorStatus status;
 315         /*@@@ 2G limits here because of the offset type: */
 316         long offset[SIMPLE_ITERATOR_MAX_PUSH_DEPTH];
 317         long first_offset; /* this is the offset to the STREAMINFO block */
 318         unsigned depth;
 319         /* this is the metadata block header of the current block we are pointing to: */
 320         FLAC__bool is_last;
 321         FLAC__MetadataType type;
 322         unsigned length;
 323 };
 324
 325 FLAC_API const char * const FLAC__Metadata_SimpleIteratorStatusString[] = {
 326         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK",
 327         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT",
 328         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE",
 329         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE",
 330         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE",
 331         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA",
 332         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR",
 333         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR",
 334         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR",
 335         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR",
 336         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR",
 337         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR",
 338         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR"
 339 };
 340
 341
 342 FLAC_API FLAC__Metadata_SimpleIterator *FLAC__metadata_simple_iterator_new()
 343 {
 344         FLAC__Metadata_SimpleIterator *iterator = (FLAC__Metadata_SimpleIterator*)calloc(1, sizeof(FLAC__Metadata_SimpleIterator));
 345
 346         if(0 != iterator) {
 347                 iterator->file = 0;
 348                 iterator->filename = 0;
 349                 iterator->tempfile_path_prefix = 0;
 350                 iterator->has_stats = false;
 351                 iterator->is_writable = false;
 352                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
 353                 iterator->first_offset = iterator->offset[0] = -1;
 354                 iterator->depth = 0;
 355         }
 356
 357         return iterator;
 358 }
 359
 360 static void simple_iterator_free_guts_(FLAC__Metadata_SimpleIterator *iterator)
 361 {
 362         FLAC__ASSERT(0 != iterator);
 363
 364         if(0 != iterator->file) {
 365                 fclose(iterator->file);
 366                 iterator->file = 0;
 367                 if(iterator->has_stats)
 368                         set_file_stats_(iterator->filename, &iterator->stats);
 369         }
 370         if(0 != iterator->filename) {
 371                 free(iterator->filename);
 372                 iterator->filename = 0;
 373         }
 374         if(0 != iterator->tempfile_path_prefix) {
 375                 free(iterator->tempfile_path_prefix);
 376                 iterator->tempfile_path_prefix = 0;
 377         }
 378 }
 379
 380 FLAC_API void FLAC__metadata_simple_iterator_delete(FLAC__Metadata_SimpleIterator *iterator)
 381 {
 382         FLAC__ASSERT(0 != iterator);
 383
 384         simple_iterator_free_guts_(iterator);
 385         free(iterator);
 386 }
 387
 388 FLAC_API FLAC__Metadata_SimpleIteratorStatus FLAC__metadata_simple_iterator_status(FLAC__Metadata_SimpleIterator *iterator)
 389 {
 390         FLAC__Metadata_SimpleIteratorStatus status;
 391
 392         FLAC__ASSERT(0 != iterator);
 393
 394         status = iterator->status;
 395         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
 396         return status;
 397 }
 398
 399 static FLAC__bool simple_iterator_prime_input_(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool read_only)
 400 {
 401         unsigned ret;
 402
 403         FLAC__ASSERT(0 != iterator);
 404
 405         if(read_only || 0 == (iterator->file = fopen(iterator->filename, "r+b"))) {
 406                 iterator->is_writable = false;
 407                 if(read_only || errno == EACCES) {
 408                         if(0 == (iterator->file = fopen(iterator->filename, "rb"))) {
 409                                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
 410                                 return false;
 411                         }
 412                 }
 413                 else {
 414                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
 415                         return false;
 416                 }
 417         }
 418         else {
 419                 iterator->is_writable = true;
 420         }
 421
 422         ret = seek_to_first_metadata_block_(iterator->file);
 423         switch(ret) {
 424                 case 0:
 425                         iterator->depth = 0;
 426                         iterator->first_offset = iterator->offset[iterator->depth] = ftell(iterator->file);
 427                         return read_metadata_block_header_(iterator);
 428                 case 1:
 429                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
 430                         return false;
 431                 case 2:
 432                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 433                         return false;
 434                 case 3:
 435                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE;
 436                         return false;
 437                 default:
 438                         FLAC__ASSERT(0);
 439                         return false;
 440         }
 441 }
 442
 443 #if 0
 444 @@@ If we decide to finish implementing this, put this comment back in metadata.h
 445 /*
 446  * The 'tempfile_path_prefix' allows you to specify a directory where
 447  * tempfiles should go.  Remember that if your metadata edits cause the
 448  * FLAC file to grow, the entire file will have to be rewritten.  If
 449  * 'tempfile_path_prefix' is NULL, the temp file will be written in the
 450  * same directory as the original FLAC file.  This makes replacing the
 451  * original with the tempfile fast but requires extra space in the same
 452  * partition for the tempfile.  If space is a problem, you can pass a
 453  * directory name belonging to a different partition in
 454  * 'tempfile_path_prefix'.  Note that you should use the forward slash
 455  * '/' as the directory separator.  A trailing slash is not needed; it
 456  * will be added automatically.
 457  */
 458 FLAC__bool FLAC__metadata_simple_iterator_init(FLAC__Metadata_SimpleIterator *iterator, const char *filename, FLAC__bool preserve_file_stats, const char *tempfile_path_prefix);
 459 #endif
 460
 461 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_init(FLAC__Metadata_SimpleIterator *iterator, const char *filename, FLAC__bool read_only, FLAC__bool preserve_file_stats)
 462 {
 463         const char *tempfile_path_prefix = 0; /*@@@ search for comments near 'rename(...)' for what it will take to finish implementing this */
 464
 465         FLAC__ASSERT(0 != iterator);
 466         FLAC__ASSERT(0 != filename);
 467
 468         simple_iterator_free_guts_(iterator);
 469
 470         if(!read_only && preserve_file_stats)
 471                 iterator->has_stats = get_file_stats_(filename, &iterator->stats);
 472
 473         if(0 == (iterator->filename = strdup(filename))) {
 474                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 475                 return false;
 476         }
 477         if(0 != tempfile_path_prefix && 0 == (iterator->tempfile_path_prefix = strdup(tempfile_path_prefix))) {
 478                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 479                 return false;
 480         }
 481
 482         return simple_iterator_prime_input_(iterator, read_only);
 483 }
 484
 485 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_is_writable(const FLAC__Metadata_SimpleIterator *iterator)
 486 {
 487         FLAC__ASSERT(0 != iterator);
 488         FLAC__ASSERT(0 != iterator->file);
 489
 490         return iterator->is_writable;
 491 }
 492
 493 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_next(FLAC__Metadata_SimpleIterator *iterator)
 494 {
 495         FLAC__ASSERT(0 != iterator);
 496         FLAC__ASSERT(0 != iterator->file);
 497
 498         if(iterator->is_last)
 499                 return false;
 500
 501         if(0 != fseek(iterator->file, iterator->length, SEEK_CUR)) {
 502                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 503                 return false;
 504         }
 505
 506         iterator->offset[iterator->depth] = ftell(iterator->file);
 507
 508         return read_metadata_block_header_(iterator);
 509 }
 510
 511 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_prev(FLAC__Metadata_SimpleIterator *iterator)
 512 {
 513         long this_offset;
 514
 515         FLAC__ASSERT(0 != iterator);
 516         FLAC__ASSERT(0 != iterator->file);
 517
 518         if(iterator->offset[iterator->depth] == iterator->first_offset)
 519                 return false;
 520
 521         if(0 != fseek(iterator->file, iterator->first_offset, SEEK_SET)) {
 522                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 523                 return false;
 524         }
 525         this_offset = iterator->first_offset;
 526         if(!read_metadata_block_header_(iterator))
 527                 return false;
 528
 529         /* we ignore any error from ftell() and catch it in fseek() */
 530         while(ftell(iterator->file) + (long)iterator->length < iterator->offset[iterator->depth]) {
 531                 if(0 != fseek(iterator->file, iterator->length, SEEK_CUR)) {
 532                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 533                         return false;
 534                 }
 535                 this_offset = ftell(iterator->file);
 536                 if(!read_metadata_block_header_(iterator))
 537                         return false;
 538         }
 539
 540         iterator->offset[iterator->depth] = this_offset;
 541
 542         return true;
 543 }
 544
 545 FLAC_API FLAC__MetadataType FLAC__metadata_simple_iterator_get_block_type(const FLAC__Metadata_SimpleIterator *iterator)
 546 {
 547         FLAC__ASSERT(0 != iterator);
 548         FLAC__ASSERT(0 != iterator->file);
 549
 550         return iterator->type;
 551 }
 552
 553 FLAC_API FLAC__StreamMetadata *FLAC__metadata_simple_iterator_get_block(FLAC__Metadata_SimpleIterator *iterator)
 554 {
 555         FLAC__StreamMetadata *block = FLAC__metadata_object_new(iterator->type);
 556
 557         FLAC__ASSERT(0 != iterator);
 558         FLAC__ASSERT(0 != iterator->file);
 559
 560         if(0 != block) {
 561                 block->is_last = iterator->is_last;
 562                 block->length = iterator->length;
 563
 564                 if(!read_metadata_block_data_(iterator, block)) {
 565                         FLAC__metadata_object_delete(block);
 566                         return 0;
 567                 }
 568
 569                 /* back up to the beginning of the block data to stay consistent */
 570                 if(0 != fseek(iterator->file, iterator->offset[iterator->depth] + FLAC__STREAM_METADATA_HEADER_LENGTH, SEEK_SET)) {
 571                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 572                         FLAC__metadata_object_delete(block);
 573                         return 0;
 574                 }
 575         }
 576         else
 577                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 578
 579         return block;
 580 }
 581
 582 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_set_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding)
 583 {
 584         FLAC__ASSERT_DECLARATION(long debug_target_offset = iterator->offset[iterator->depth];)
 585         FLAC__bool ret;
 586
 587         FLAC__ASSERT(0 != iterator);
 588         FLAC__ASSERT(0 != iterator->file);
 589         FLAC__ASSERT(0 != block);
 590
 591         if(!iterator->is_writable) {
 592                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE;
 593                 return false;
 594         }
 595
 596         if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO || block->type == FLAC__METADATA_TYPE_STREAMINFO) {
 597                 if(iterator->type != block->type) {
 598                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 599                         return false;
 600                 }
 601         }
 602
 603         block->is_last = iterator->is_last;
 604
 605         if(iterator->length == block->length)
 606                 return write_metadata_block_stationary_(iterator, block);
 607         else if(iterator->length > block->length) {
 608                 if(use_padding && iterator->length >= FLAC__STREAM_METADATA_HEADER_LENGTH + block->length) {
 609                         ret = write_metadata_block_stationary_with_padding_(iterator, block, iterator->length - FLAC__STREAM_METADATA_HEADER_LENGTH - block->length, block->is_last);
 610                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 611                         FLAC__ASSERT(!ret || ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 612                         return ret;
 613                 }
 614                 else {
 615                         ret = rewrite_whole_file_(iterator, block, /*append=*/false);
 616                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 617                         FLAC__ASSERT(!ret || ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 618                         return ret;
 619                 }
 620         }
 621         else /* iterator->length < block->length */ {
 622                 unsigned padding_leftover = 0;
 623                 FLAC__bool padding_is_last = false;
 624                 if(use_padding) {
 625                         /* first see if we can even use padding */
 626                         if(iterator->is_last) {
 627                                 use_padding = false;
 628                         }
 629                         else {
 630                                 const unsigned extra_padding_bytes_required = block->length - iterator->length;
 631                                 simple_iterator_push_(iterator);
 632                                 if(!FLAC__metadata_simple_iterator_next(iterator)) {
 633                                         (void)simple_iterator_pop_(iterator);
 634                                         return false;
 635                                 }
 636                                 if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
 637                                         use_padding = false;
 638                                 }
 639                                 else {
 640                                         if(FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length == extra_padding_bytes_required) {
 641                                                 padding_leftover = 0;
 642                                                 block->is_last = iterator->is_last;
 643                                         }
 644                                         else if(iterator->length < extra_padding_bytes_required)
 645                                                 use_padding = false;
 646                                         else {
 647                                                 padding_leftover = FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length - extra_padding_bytes_required;
 648                                                 padding_is_last = iterator->is_last;
 649                                                 block->is_last = false;
 650                                         }
 651                                 }
 652                                 if(!simple_iterator_pop_(iterator))
 653                                         return false;
 654                         }
 655                 }
 656                 if(use_padding) {
 657                         if(padding_leftover == 0) {
 658                                 ret = write_metadata_block_stationary_(iterator, block);
 659                                 FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 660                                 FLAC__ASSERT(!ret || ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 661                                 return ret;
 662                         }
 663                         else {
 664                                 FLAC__ASSERT(padding_leftover >= FLAC__STREAM_METADATA_HEADER_LENGTH);
 665                                 ret = write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover - FLAC__STREAM_METADATA_HEADER_LENGTH, padding_is_last);
 666                                 FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 667                                 FLAC__ASSERT(!ret || ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 668                                 return ret;
 669                         }
 670                 }
 671                 else {
 672                         ret = rewrite_whole_file_(iterator, block, /*append=*/false);
 673                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 674                         FLAC__ASSERT(!ret || ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 675                         return ret;
 676                 }
 677         }
 678 }
 679
 680 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_insert_block_after(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding)
 681 {
 682         unsigned padding_leftover = 0;
 683         FLAC__bool padding_is_last = false;
 684
 685         FLAC__ASSERT_DECLARATION(long debug_target_offset = iterator->offset[iterator->depth] + FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length;)
 686         FLAC__bool ret;
 687
 688         FLAC__ASSERT(0 != iterator);
 689         FLAC__ASSERT(0 != iterator->file);
 690         FLAC__ASSERT(0 != block);
 691
 692         if(!iterator->is_writable)
 693                 return false;
 694
 695         if(block->type == FLAC__METADATA_TYPE_STREAMINFO) {
 696                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 697                 return false;
 698         }
 699
 700         block->is_last = iterator->is_last;
 701
 702         if(use_padding) {
 703                 /* first see if we can even use padding */
 704                 if(iterator->is_last) {
 705                         use_padding = false;
 706                 }
 707                 else {
 708                         simple_iterator_push_(iterator);
 709                         if(!FLAC__metadata_simple_iterator_next(iterator)) {
 710                                 (void)simple_iterator_pop_(iterator);
 711                                 return false;
 712                         }
 713                         if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
 714                                 use_padding = false;
 715                         }
 716                         else {
 717                                 if(iterator->length == block->length) {
 718                                         padding_leftover = 0;
 719                                         block->is_last = iterator->is_last;
 720                                 }
 721                                 else if(iterator->length < FLAC__STREAM_METADATA_HEADER_LENGTH + block->length)
 722                                         use_padding = false;
 723                                 else {
 724                                         padding_leftover = iterator->length - block->length;
 725                                         padding_is_last = iterator->is_last;
 726                                         block->is_last = false;
 727                                 }
 728                         }
 729                         if(!simple_iterator_pop_(iterator))
 730                                 return false;
 731                 }
 732         }
 733         if(use_padding) {
 734                 /* move to the next block, which is suitable padding */
 735                 if(!FLAC__metadata_simple_iterator_next(iterator))
 736                         return false;
 737                 if(padding_leftover == 0) {
 738                         ret = write_metadata_block_stationary_(iterator, block);
 739                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 740                         FLAC__ASSERT(ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 741                         return ret;
 742                 }
 743                 else {
 744                         FLAC__ASSERT(padding_leftover >= FLAC__STREAM_METADATA_HEADER_LENGTH);
 745                         ret = write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover - FLAC__STREAM_METADATA_HEADER_LENGTH, padding_is_last);
 746                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 747                         FLAC__ASSERT(ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 748                         return ret;
 749                 }
 750         }
 751         else {
 752                 ret = rewrite_whole_file_(iterator, block, /*append=*/true);
 753                 FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 754                 FLAC__ASSERT(ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
 755                 return ret;
 756         }
 757 }
 758
 759 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_delete_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool use_padding)
 760 {
 761         FLAC__ASSERT_DECLARATION(long debug_target_offset = iterator->offset[iterator->depth];)
 762         FLAC__bool ret;
 763
 764         if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO) {
 765                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 766                 return false;
 767         }
 768
 769         if(use_padding) {
 770                 FLAC__StreamMetadata *padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING);
 771                 if(0 == padding) {
 772                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 773                         return false;
 774                 }
 775                 padding->length = iterator->length;
 776                 if(!FLAC__metadata_simple_iterator_set_block(iterator, padding, false)) {
 777                         FLAC__metadata_object_delete(padding);
 778                         return false;
 779                 }
 780                 FLAC__metadata_object_delete(padding);
 781                 if(!FLAC__metadata_simple_iterator_prev(iterator))
 782                         return false;
 783                 FLAC__ASSERT(iterator->offset[iterator->depth] + (long)FLAC__STREAM_METADATA_HEADER_LENGTH + (long)iterator->length == debug_target_offset);
 784                 FLAC__ASSERT(ftell(iterator->file) + (long)iterator->length == debug_target_offset);
 785                 return true;
 786         }
 787         else {
 788                 ret = rewrite_whole_file_(iterator, 0, /*append=*/false);
 789                 FLAC__ASSERT(iterator->offset[iterator->depth] + (long)FLAC__STREAM_METADATA_HEADER_LENGTH + (long)iterator->length == debug_target_offset);
 790                 FLAC__ASSERT(ftell(iterator->file) + (long)iterator->length == debug_target_offset);
 791                 return ret;
 792         }
 793 }
 794
 795
 796
 797 /****************************************************************************
 798  *
 799  * Level 2 implementation
 800  *
 801  ***************************************************************************/
 802
 803
 804 typedef struct FLAC__Metadata_Node {
 805         FLAC__StreamMetadata *data;
 806         struct FLAC__Metadata_Node *prev, *next;
 807 } FLAC__Metadata_Node;
 808
 809 struct FLAC__Metadata_Chain {
 810         char *filename; /* will be NULL if using callbacks */
 811         FLAC__Metadata_Node *head;
 812         FLAC__Metadata_Node *tail;
 813         unsigned nodes;
 814         FLAC__Metadata_ChainStatus status;
 815         long first_offset, last_offset; /*@@@ 2G limit */
 816         /*
 817          * This is the length of the chain initially read from the FLAC file.
 818          * it is used to compare against the current length to decide whether
 819          * or not the whole file has to be rewritten.
 820          */
 821         unsigned initial_length; /*@@@ 4G limit */
 822 };
 823
 824 struct FLAC__Metadata_Iterator {
 825         FLAC__Metadata_Chain *chain;
 826         FLAC__Metadata_Node *current;
 827 };
 828
 829 FLAC_API const char * const FLAC__Metadata_ChainStatusString[] = {
 830         "FLAC__METADATA_CHAIN_STATUS_OK",
 831         "FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT",
 832         "FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE",
 833         "FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE",
 834         "FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE",
 835         "FLAC__METADATA_CHAIN_STATUS_BAD_METADATA",
 836         "FLAC__METADATA_CHAIN_STATUS_READ_ERROR",
 837         "FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR",
 838         "FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR",
 839         "FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR",
 840         "FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR",
 841         "FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR",
 842         "FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR",
 843         "FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS",
 844         "FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH",
 845         "FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL"
 846 };
 847
 848
 849 static FLAC__Metadata_Node *node_new_()
 850 {
 851         return (FLAC__Metadata_Node*)calloc(1, sizeof(FLAC__Metadata_Node));
 852 }
 853
 854 static void node_delete_(FLAC__Metadata_Node *node)
 855 {
 856         FLAC__ASSERT(0 != node);
 857         if(0 != node->data)
 858                 FLAC__metadata_object_delete(node->data);
 859         free(node);
 860 }
 861
 862 static void chain_init_(FLAC__Metadata_Chain *chain)
 863 {
 864         FLAC__ASSERT(0 != chain);
 865
 866         chain->filename = 0;
 867         chain->head = chain->tail = 0;
 868         chain->nodes = 0;
 869         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
 870         chain->initial_length = 0;
 871 }
 872
 873 static void chain_clear_(FLAC__Metadata_Chain *chain)
 874 {
 875         FLAC__Metadata_Node *node, *next;
 876
 877         FLAC__ASSERT(0 != chain);
 878
 879         for(node = chain->head; node; ) {
 880                 next = node->next;
 881                 node_delete_(node);
 882                 node = next;
 883         }
 884
 885         if(0 != chain->filename)
 886                 free(chain->filename);
 887
 888         chain_init_(chain);
 889 }
 890
 891 static void chain_append_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 892 {
 893         FLAC__ASSERT(0 != chain);
 894         FLAC__ASSERT(0 != node);
 895         FLAC__ASSERT(0 != node->data);
 896
 897         node->next = node->prev = 0;
 898         node->data->is_last = true;
 899         if(0 != chain->tail)
 900                 chain->tail->data->is_last = false;
 901
 902         if(0 == chain->head)
 903                 chain->head = node;
 904         else {
 905                 FLAC__ASSERT(0 != chain->tail);
 906                 chain->tail->next = node;
 907                 node->prev = chain->tail;
 908         }
 909         chain->tail = node;
 910         chain->nodes++;
 911 }
 912
 913 static void chain_remove_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 914 {
 915         FLAC__ASSERT(0 != chain);
 916         FLAC__ASSERT(0 != node);
 917
 918         if(node == chain->head)
 919                 chain->head = node->next;
 920         else
 921                 node->prev->next = node->next;
 922
 923         if(node == chain->tail)
 924                 chain->tail = node->prev;
 925         else
 926                 node->next->prev = node->prev;
 927
 928         if(0 != chain->tail)
 929                 chain->tail->data->is_last = true;
 930
 931         chain->nodes--;
 932 }
 933
 934 static void chain_delete_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 935 {
 936         chain_remove_node_(chain, node);
 937         node_delete_(node);
 938 }
 939
 940 static unsigned chain_calculate_length_(FLAC__Metadata_Chain *chain)
 941 {
 942         const FLAC__Metadata_Node *node;
 943         unsigned length = 0;
 944         for(node = chain->head; node; node = node->next)
 945                 length += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
 946         return length;
 947 }
 948
 949 static void iterator_insert_node_(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Node *node)
 950 {
 951         FLAC__ASSERT(0 != node);
 952         FLAC__ASSERT(0 != node->data);
 953         FLAC__ASSERT(0 != iterator);
 954         FLAC__ASSERT(0 != iterator->current);
 955         FLAC__ASSERT(0 != iterator->chain);
 956         FLAC__ASSERT(0 != iterator->chain->head);
 957         FLAC__ASSERT(0 != iterator->chain->tail);
 958
 959         node->data->is_last = false;
 960
 961         node->prev = iterator->current->prev;
 962         node->next = iterator->current;
 963
 964         if(0 == node->prev)
 965                 iterator->chain->head = node;
 966         else
 967                 node->prev->next = node;
 968
 969         iterator->current->prev = node;
 970
 971         iterator->chain->nodes++;
 972 }
 973
 974 static void iterator_insert_node_after_(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Node *node)
 975 {
 976         FLAC__ASSERT(0 != node);
 977         FLAC__ASSERT(0 != node->data);
 978         FLAC__ASSERT(0 != iterator);
 979         FLAC__ASSERT(0 != iterator->current);
 980         FLAC__ASSERT(0 != iterator->chain);
 981         FLAC__ASSERT(0 != iterator->chain->head);
 982         FLAC__ASSERT(0 != iterator->chain->tail);
 983
 984         iterator->current->data->is_last = false;
 985
 986         node->prev = iterator->current;
 987         node->next = iterator->current->next;
 988
 989         if(0 == node->next)
 990                 iterator->chain->tail = node;
 991         else
 992                 node->next->prev = node;
 993
 994         node->prev->next = node;
 995
 996         iterator->chain->tail->data->is_last = true;
 997
 998         iterator->chain->nodes++;
 999 }
1000
1001 /* return true iff node and node->next are both padding */
1002 static FLAC__bool chain_merge_adjacent_padding_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
1003 {
1004         if(node->data->type == FLAC__METADATA_TYPE_PADDING && 0 != node->next && node->next->data->type == FLAC__METADATA_TYPE_PADDING) {
1005                 const unsigned growth = FLAC__STREAM_METADATA_HEADER_LENGTH + node->next->data->length;
1006                 node->data->length += growth;
1007
1008                 chain_delete_node_(chain, node->next);
1009                 return true;
1010         }
1011         else
1012                 return false;
1013 }
1014
1015 /* Returns the new length of the chain, or 0 if there was an error. */
1016 /* WATCHOUT: This can get called multiple times before a write, so
1017  * it should still work when this happens.
1018  */
1019 /* WATCHOUT: Make sure to also update the logic in
1020  * FLAC__metadata_chain_check_if_tempfile_needed() if the logic here changes.
1021  */
1022 static unsigned chain_prepare_for_write_(FLAC__Metadata_Chain *chain, FLAC__bool use_padding)
1023 {
1024         unsigned current_length = chain_calculate_length_(chain);
1025
1026         if(use_padding) {
1027                 /* if the metadata shrank and the last block is padding, we just extend the last padding block */
1028                 if(current_length < chain->initial_length && chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1029                         const unsigned delta = chain->initial_length - current_length;
1030                         chain->tail->data->length += delta;
1031                         current_length += delta;
1032                         FLAC__ASSERT(current_length == chain->initial_length);
1033                 }
1034                 /* if the metadata shrank more than 4 bytes then there's room to add another padding block */
1035                 else if(current_length + FLAC__STREAM_METADATA_HEADER_LENGTH <= chain->initial_length) {
1036                         FLAC__StreamMetadata *padding;
1037                         FLAC__Metadata_Node *node;
1038                         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING))) {
1039                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1040                                 return 0;
1041                         }
1042                         padding->length = chain->initial_length - (FLAC__STREAM_METADATA_HEADER_LENGTH + current_length);
1043                         if(0 == (node = node_new_())) {
1044                                 FLAC__metadata_object_delete(padding);
1045                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1046                                 return 0;
1047                         }
1048                         node->data = padding;
1049                         chain_append_node_(chain, node);
1050                         current_length = chain_calculate_length_(chain);
1051                         FLAC__ASSERT(current_length == chain->initial_length);
1052                 }
1053                 /* if the metadata grew but the last block is padding, try cutting the padding to restore the original length so we don't have to rewrite the whole file */
1054                 else if(current_length > chain->initial_length) {
1055                         const unsigned delta = current_length - chain->initial_length;
1056                         if(chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1057                                 /* if the delta is exactly the size of the last padding block, remove the padding block */
1058                                 if(chain->tail->data->length + FLAC__STREAM_METADATA_HEADER_LENGTH == delta) {
1059                                         chain_delete_node_(chain, chain->tail);
1060                                         current_length = chain_calculate_length_(chain);
1061                                         FLAC__ASSERT(current_length == chain->initial_length);
1062                                 }
1063                                 /* if there is at least 'delta' bytes of padding, trim the padding down */
1064                                 else if(chain->tail->data->length >= delta) {
1065                                         chain->tail->data->length -= delta;
1066                                         current_length -= delta;
1067                                         FLAC__ASSERT(current_length == chain->initial_length);
1068                                 }
1069                         }
1070                 }
1071         }
1072
1073         return current_length;
1074 }
1075
1076 static FLAC__bool chain_read_cb_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb, FLAC__IOCallback_Tell tell_cb)
1077 {
1078         FLAC__Metadata_Node *node;
1079
1080         FLAC__ASSERT(0 != chain);
1081
1082         /* we assume we're already at the beginning of the file */
1083
1084         switch(seek_to_first_metadata_block_cb_(handle, read_cb, seek_cb)) {
1085                 case 0:
1086                         break;
1087                 case 1:
1088                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1089                         return false;
1090                 case 2:
1091                         chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1092                         return false;
1093                 case 3:
1094                         chain->status = FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE;
1095                         return false;
1096                 default:
1097                         FLAC__ASSERT(0);
1098                         return false;
1099         }
1100
1101         {
1102                 FLAC__int64 pos = tell_cb(handle);
1103                 if(pos < 0) {
1104                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1105                         return false;
1106                 }
1107                 chain->first_offset = (long)pos;
1108         }
1109
1110         {
1111                 FLAC__bool is_last;
1112                 FLAC__MetadataType type;
1113                 unsigned length;
1114
1115                 do {
1116                         node = node_new_();
1117                         if(0 == node) {
1118                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1119                                 return false;
1120                         }
1121
1122                         if(!read_metadata_block_header_cb_(handle, read_cb, &is_last, &type, &length)) {
1123                                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1124                                 return false;
1125                         }
1126
1127                         node->data = FLAC__metadata_object_new(type);
1128                         if(0 == node->data) {
1129                                 node_delete_(node);
1130                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1131                                 return false;
1132                         }
1133
1134                         node->data->is_last = is_last;
1135                         node->data->length = length;
1136
1137                         chain->status = get_equivalent_status_(read_metadata_block_data_cb_(handle, read_cb, seek_cb, node->data));
1138                         if(chain->status != FLAC__METADATA_CHAIN_STATUS_OK) {
1139                                 node_delete_(node);
1140                                 return false;
1141                         }
1142                         chain_append_node_(chain, node);
1143                 } while(!is_last);
1144         }
1145
1146         {
1147                 FLAC__int64 pos = tell_cb(handle);
1148                 if(pos < 0) {
1149                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1150                         return false;
1151                 }
1152                 chain->last_offset = (long)pos;
1153         }
1154
1155         chain->initial_length = chain_calculate_length_(chain);
1156
1157         return true;
1158 }
1159
1160 static FLAC__bool chain_rewrite_metadata_in_place_cb_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, FLAC__IOCallback_Seek seek_cb)
1161 {
1162         FLAC__Metadata_Node *node;
1163
1164         FLAC__ASSERT(0 != chain);
1165         FLAC__ASSERT(0 != chain->head);
1166
1167         if(0 != seek_cb(handle, chain->first_offset, SEEK_SET)) {
1168                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1169                 return false;
1170         }
1171
1172         for(node = chain->head; node; node = node->next) {
1173                 if(!write_metadata_block_header_cb_(handle, write_cb, node->data)) {
1174                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1175                         return false;
1176                 }
1177                 if(!write_metadata_block_data_cb_(handle, write_cb, node->data)) {
1178                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1179                         return false;
1180                 }
1181         }
1182
1183         /*FLAC__ASSERT(fflush(), ftell() == chain->last_offset);*/
1184
1185         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
1186         return true;
1187 }
1188
1189 static FLAC__bool chain_rewrite_metadata_in_place_(FLAC__Metadata_Chain *chain)
1190 {
1191         FILE *file;
1192         FLAC__bool ret;
1193
1194         FLAC__ASSERT(0 != chain->filename);
1195
1196         if(0 == (file = fopen(chain->filename, "r+b"))) {
1197                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1198                 return false;
1199         }
1200
1201         /* chain_rewrite_metadata_in_place_cb_() sets chain->status for us */
1202         ret = chain_rewrite_metadata_in_place_cb_(chain, (FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, fseek_wrapper_);
1203
1204         fclose(file);
1205
1206         return ret;
1207 }
1208
1209 static FLAC__bool chain_rewrite_file_(FLAC__Metadata_Chain *chain, const char *tempfile_path_prefix)
1210 {
1211         FILE *f, *tempfile;
1212         char *tempfilename;
1213         FLAC__Metadata_SimpleIteratorStatus status;
1214         const FLAC__Metadata_Node *node;
1215
1216         FLAC__ASSERT(0 != chain);
1217         FLAC__ASSERT(0 != chain->filename);
1218         FLAC__ASSERT(0 != chain->head);
1219
1220         /* copy the file prefix (data up to first metadata block */
1221         if(0 == (f = fopen(chain->filename, "rb"))) {
1222                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1223                 return false;
1224         }
1225         if(!open_tempfile_(chain->filename, tempfile_path_prefix, &tempfile, &tempfilename, &status)) {
1226                 chain->status = get_equivalent_status_(status);
1227                 cleanup_tempfile_(&tempfile, &tempfilename);
1228                 return false;
1229         }
1230         if(!copy_n_bytes_from_file_(f, tempfile, chain->first_offset, &status)) {
1231                 chain->status = get_equivalent_status_(status);
1232                 cleanup_tempfile_(&tempfile, &tempfilename);
1233                 return false;
1234         }
1235
1236         /* write the metadata */
1237         for(node = chain->head; node; node = node->next) {
1238                 if(!write_metadata_block_header_(tempfile, &status, node->data)) {
1239                         chain->status = get_equivalent_status_(status);
1240                         return false;
1241                 }
1242                 if(!write_metadata_block_data_(tempfile, &status, node->data)) {
1243                         chain->status = get_equivalent_status_(status);
1244                         return false;
1245                 }
1246         }
1247         /*FLAC__ASSERT(fflush(), ftell() == chain->last_offset);*/
1248
1249         /* copy the file postfix (everything after the metadata) */
1250         if(0 != fseek(f, chain->last_offset, SEEK_SET)) {
1251                 cleanup_tempfile_(&tempfile, &tempfilename);
1252                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1253                 return false;
1254         }
1255         if(!copy_remaining_bytes_from_file_(f, tempfile, &status)) {
1256                 cleanup_tempfile_(&tempfile, &tempfilename);
1257                 chain->status = get_equivalent_status_(status);
1258                 return false;
1259         }
1260
1261         /* move the tempfile on top of the original */
1262         (void)fclose(f);
1263         if(!transport_tempfile_(chain->filename, &tempfile, &tempfilename, &status))
1264                 return false;
1265
1266         return true;
1267 }
1268
1269 static FLAC__bool chain_rewrite_file_cb_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb, FLAC__IOCallback_Eof eof_cb, FLAC__IOHandle temp_handle, FLAC__IOCallback_Write temp_write_cb)
1270 {
1271         FLAC__Metadata_SimpleIteratorStatus status;
1272         const FLAC__Metadata_Node *node;
1273
1274         FLAC__ASSERT(0 != chain);
1275         FLAC__ASSERT(0 == chain->filename);
1276         FLAC__ASSERT(0 != chain->head);
1277
1278         /* copy the file prefix (data up to first metadata block */
1279         if(!copy_n_bytes_from_file_cb_(handle, read_cb, temp_handle, temp_write_cb, chain->first_offset, &status)) {
1280                 chain->status = get_equivalent_status_(status);
1281                 return false;
1282         }
1283
1284         /* write the metadata */
1285         for(node = chain->head; node; node = node->next) {
1286                 if(!write_metadata_block_header_cb_(temp_handle, temp_write_cb, node->data)) {
1287                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1288                         return false;
1289                 }
1290                 if(!write_metadata_block_data_cb_(temp_handle, temp_write_cb, node->data)) {
1291                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1292                         return false;
1293                 }
1294         }
1295         /*FLAC__ASSERT(fflush(), ftell() == chain->last_offset);*/
1296
1297         /* copy the file postfix (everything after the metadata) */
1298         if(0 != seek_cb(handle, chain->last_offset, SEEK_SET)) {
1299                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1300                 return false;
1301         }
1302         if(!copy_remaining_bytes_from_file_cb_(handle, read_cb, eof_cb, temp_handle, temp_write_cb, &status)) {
1303                 chain->status = get_equivalent_status_(status);
1304                 return false;
1305         }
1306
1307         return true;
1308 }
1309
1310 FLAC_API FLAC__Metadata_Chain *FLAC__metadata_chain_new()
1311 {
1312         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)calloc(1, sizeof(FLAC__Metadata_Chain));
1313
1314         if(0 != chain)
1315                 chain_init_(chain);
1316
1317         return chain;
1318 }
1319
1320 FLAC_API void FLAC__metadata_chain_delete(FLAC__Metadata_Chain *chain)
1321 {
1322         FLAC__ASSERT(0 != chain);
1323
1324         chain_clear_(chain);
1325
1326         free(chain);
1327 }
1328
1329 FLAC_API FLAC__Metadata_ChainStatus FLAC__metadata_chain_status(FLAC__Metadata_Chain *chain)
1330 {
1331         FLAC__Metadata_ChainStatus status;
1332
1333         FLAC__ASSERT(0 != chain);
1334
1335         status = chain->status;
1336         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
1337         return status;
1338 }
1339
1340 FLAC_API FLAC__bool FLAC__metadata_chain_read(FLAC__Metadata_Chain *chain, const char *filename)
1341 {
1342         FILE *file;
1343         FLAC__bool ret;
1344
1345         FLAC__ASSERT(0 != chain);
1346         FLAC__ASSERT(0 != filename);
1347
1348         chain_clear_(chain);
1349
1350         if(0 == (chain->filename = strdup(filename))) {
1351                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1352                 return false;
1353         }
1354
1355         if(0 == (file = fopen(filename, "rb"))) {
1356                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1357                 return false;
1358         }
1359
1360         /* chain_read_cb_() sets chain->status for us */
1361         ret = chain_read_cb_(chain, file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, ftell_wrapper_);
1362
1363         fclose(file);
1364
1365         return ret;
1366 }
1367
1368 FLAC_API FLAC__bool FLAC__metadata_chain_read_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1369 {
1370         FLAC__ASSERT(0 != chain);
1371
1372         chain_clear_(chain);
1373
1374         if (0 == callbacks.read || 0 == callbacks.seek || 0 == callbacks.tell) {
1375                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1376                 return false;
1377         }
1378
1379         if(!chain_read_cb_(chain, handle, callbacks.read, callbacks.seek, callbacks.tell))
1380                 return false; /* chain->status is already set by chain_read_cb_ */
1381
1382         return true;
1383 }
1384
1385 FLAC_API FLAC__bool FLAC__metadata_chain_check_if_tempfile_needed(FLAC__Metadata_Chain *chain, FLAC__bool use_padding)
1386 {
1387         /* This does all the same checks that are in chain_prepare_for_write_()
1388          * but doesn't actually alter the chain.  Make sure to update the logic
1389          * here if chain_prepare_for_write_() changes.
1390          */
1391         const unsigned current_length = chain_calculate_length_(chain);
1392
1393         FLAC__ASSERT(0 != chain);
1394
1395         if(use_padding) {
1396                 /* if the metadata shrank and the last block is padding, we just extend the last padding block */
1397                 if(current_length < chain->initial_length && chain->tail->data->type == FLAC__METADATA_TYPE_PADDING)
1398                         return false;
1399                 /* if the metadata shrank more than 4 bytes then there's room to add another padding block */
1400                 else if(current_length + FLAC__STREAM_METADATA_HEADER_LENGTH <= chain->initial_length)
1401                         return false;
1402                 /* if the metadata grew but the last block is padding, try cutting the padding to restore the original length so we don't have to rewrite the whole file */
1403                 else if(current_length > chain->initial_length) {
1404                         const unsigned delta = current_length - chain->initial_length;
1405                         if(chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1406                                 /* if the delta is exactly the size of the last padding block, remove the padding block */
1407                                 if(chain->tail->data->length + FLAC__STREAM_METADATA_HEADER_LENGTH == delta)
1408                                         return false;
1409                                 /* if there is at least 'delta' bytes of padding, trim the padding down */
1410                                 else if(chain->tail->data->length >= delta)
1411                                         return false;
1412                         }
1413                 }
1414         }
1415
1416         return (current_length != chain->initial_length);
1417 }
1418
1419 FLAC_API FLAC__bool FLAC__metadata_chain_write(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__bool preserve_file_stats)
1420 {
1421         struct stat stats;
1422         const char *tempfile_path_prefix = 0;
1423         unsigned current_length;
1424
1425         FLAC__ASSERT(0 != chain);
1426
1427         if (0 == chain->filename) {
1428                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1429                 return false;
1430         }
1431
1432         current_length = chain_prepare_for_write_(chain, use_padding);
1433
1434         /* a return value of 0 means there was an error; chain->status is already set */
1435         if (0 == current_length)
1436                 return false;
1437
1438         if(preserve_file_stats)
1439                 get_file_stats_(chain->filename, &stats);
1440
1441         if(current_length == chain->initial_length) {
1442                 if(!chain_rewrite_metadata_in_place_(chain))
1443                         return false;
1444         }
1445         else {
1446                 if(!chain_rewrite_file_(chain, tempfile_path_prefix))
1447                         return false;
1448
1449                 /* recompute lengths and offsets */
1450                 {
1451                         const FLAC__Metadata_Node *node;
1452                         chain->initial_length = current_length;
1453                         chain->last_offset = chain->first_offset;
1454                         for(node = chain->head; node; node = node->next)
1455                                 chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1456                 }
1457         }
1458
1459         if(preserve_file_stats)
1460                 set_file_stats_(chain->filename, &stats);
1461
1462         return true;
1463 }
1464
1465 FLAC_API FLAC__bool FLAC__metadata_chain_write_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1466 {
1467         unsigned current_length;
1468
1469         FLAC__ASSERT(0 != chain);
1470
1471         if (0 != chain->filename) {
1472                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1473                 return false;
1474         }
1475
1476         if (0 == callbacks.write || 0 == callbacks.seek) {
1477                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1478                 return false;
1479         }
1480
1481         if (FLAC__metadata_chain_check_if_tempfile_needed(chain, use_padding)) {
1482                 chain->status = FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL;
1483                 return false;
1484         }
1485
1486         current_length = chain_prepare_for_write_(chain, use_padding);
1487
1488         /* a return value of 0 means there was an error; chain->status is already set */
1489         if (0 == current_length)
1490                 return false;
1491
1492         FLAC__ASSERT(current_length == chain->initial_length);
1493
1494         return chain_rewrite_metadata_in_place_cb_(chain, handle, callbacks.write, callbacks.seek);
1495 }
1496
1497 FLAC_API FLAC__bool FLAC__metadata_chain_write_with_callbacks_and_tempfile(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks, FLAC__IOHandle temp_handle, FLAC__IOCallbacks temp_callbacks)
1498 {
1499         unsigned current_length;
1500
1501         FLAC__ASSERT(0 != chain);
1502
1503         if (0 != chain->filename) {
1504                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1505                 return false;
1506         }
1507
1508         if (0 == callbacks.read || 0 == callbacks.seek || 0 == callbacks.eof) {
1509                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1510                 return false;
1511         }
1512         if (0 == temp_callbacks.write) {
1513                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1514                 return false;
1515         }
1516
1517         if (!FLAC__metadata_chain_check_if_tempfile_needed(chain, use_padding)) {
1518                 chain->status = FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL;
1519                 return false;
1520         }
1521
1522         current_length = chain_prepare_for_write_(chain, use_padding);
1523
1524         /* a return value of 0 means there was an error; chain->status is already set */
1525         if (0 == current_length)
1526                 return false;
1527
1528         FLAC__ASSERT(current_length != chain->initial_length);
1529
1530         if(!chain_rewrite_file_cb_(chain, handle, callbacks.read, callbacks.seek, callbacks.eof, temp_handle, temp_callbacks.write))
1531                 return false;
1532
1533         /* recompute lengths and offsets */
1534         {
1535                 const FLAC__Metadata_Node *node;
1536                 chain->initial_length = current_length;
1537                 chain->last_offset = chain->first_offset;
1538                 for(node = chain->head; node; node = node->next)
1539                         chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1540         }
1541
1542         return true;
1543 }
1544
1545 FLAC_API void FLAC__metadata_chain_merge_padding(FLAC__Metadata_Chain *chain)
1546 {
1547         FLAC__Metadata_Node *node;
1548
1549         FLAC__ASSERT(0 != chain);
1550
1551         for(node = chain->head; node; ) {
1552                 if(!chain_merge_adjacent_padding_(chain, node))
1553                         node = node->next;
1554         }
1555 }
1556
1557 FLAC_API void FLAC__metadata_chain_sort_padding(FLAC__Metadata_Chain *chain)
1558 {
1559         FLAC__Metadata_Node *node, *save;
1560         unsigned i;
1561
1562         FLAC__ASSERT(0 != chain);
1563
1564         /*
1565          * Don't try and be too smart... this simple algo is good enough for
1566          * the small number of nodes that we deal with.
1567          */
1568         for(i = 0, node = chain->head; i < chain->nodes; i++) {
1569                 if(node->data->type == FLAC__METADATA_TYPE_PADDING) {
1570                         save = node->next;
1571                         chain_remove_node_(chain, node);
1572                         chain_append_node_(chain, node);
1573                         node = save;
1574                 }
1575                 else {
1576                         node = node->next;
1577                 }
1578         }
1579
1580         FLAC__metadata_chain_merge_padding(chain);
1581 }
1582
1583
1584 FLAC_API FLAC__Metadata_Iterator *FLAC__metadata_iterator_new()
1585 {
1586         FLAC__Metadata_Iterator *iterator = (FLAC__Metadata_Iterator*)calloc(1, sizeof(FLAC__Metadata_Iterator));
1587
1588         /* calloc() implies:
1589                 iterator->current = 0;
1590                 iterator->chain = 0;
1591         */
1592
1593         return iterator;
1594 }
1595
1596 FLAC_API void FLAC__metadata_iterator_delete(FLAC__Metadata_Iterator *iterator)
1597 {
1598         FLAC__ASSERT(0 != iterator);
1599
1600         free(iterator);
1601 }
1602
1603 FLAC_API void FLAC__metadata_iterator_init(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Chain *chain)
1604 {
1605         FLAC__ASSERT(0 != iterator);
1606         FLAC__ASSERT(0 != chain);
1607         FLAC__ASSERT(0 != chain->head);
1608
1609         iterator->chain = chain;
1610         iterator->current = chain->head;
1611 }
1612
1613 FLAC_API FLAC__bool FLAC__metadata_iterator_next(FLAC__Metadata_Iterator *iterator)
1614 {
1615         FLAC__ASSERT(0 != iterator);
1616
1617         if(0 == iterator->current || 0 == iterator->current->next)
1618                 return false;
1619
1620         iterator->current = iterator->current->next;
1621         return true;
1622 }
1623
1624 FLAC_API FLAC__bool FLAC__metadata_iterator_prev(FLAC__Metadata_Iterator *iterator)
1625 {
1626         FLAC__ASSERT(0 != iterator);
1627
1628         if(0 == iterator->current || 0 == iterator->current->prev)
1629                 return false;
1630
1631         iterator->current = iterator->current->prev;
1632         return true;
1633 }
1634
1635 FLAC_API FLAC__MetadataType FLAC__metadata_iterator_get_block_type(const FLAC__Metadata_Iterator *iterator)
1636 {
1637         FLAC__ASSERT(0 != iterator);
1638         FLAC__ASSERT(0 != iterator->current);
1639         FLAC__ASSERT(0 != iterator->current->data);
1640
1641         return iterator->current->data->type;
1642 }
1643
1644 FLAC_API FLAC__StreamMetadata *FLAC__metadata_iterator_get_block(FLAC__Metadata_Iterator *iterator)
1645 {
1646         FLAC__ASSERT(0 != iterator);
1647         FLAC__ASSERT(0 != iterator->current);
1648
1649         return iterator->current->data;
1650 }
1651
1652 FLAC_API FLAC__bool FLAC__metadata_iterator_set_block(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1653 {
1654         FLAC__ASSERT(0 != iterator);
1655         FLAC__ASSERT(0 != block);
1656         return FLAC__metadata_iterator_delete_block(iterator, false) && FLAC__metadata_iterator_insert_block_after(iterator, block);
1657 }
1658
1659 FLAC_API FLAC__bool FLAC__metadata_iterator_delete_block(FLAC__Metadata_Iterator *iterator, FLAC__bool replace_with_padding)
1660 {
1661         FLAC__Metadata_Node *save;
1662
1663         FLAC__ASSERT(0 != iterator);
1664         FLAC__ASSERT(0 != iterator->current);
1665
1666         if(0 == iterator->current->prev) {
1667                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1668                 return false;
1669         }
1670
1671         save = iterator->current->prev;
1672
1673         if(replace_with_padding) {
1674                 FLAC__metadata_object_delete_data(iterator->current->data);
1675                 iterator->current->data->type = FLAC__METADATA_TYPE_PADDING;
1676         }
1677         else {
1678                 chain_delete_node_(iterator->chain, iterator->current);
1679         }
1680
1681         iterator->current = save;
1682         return true;
1683 }
1684
1685 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_before(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1686 {
1687         FLAC__Metadata_Node *node;
1688
1689         FLAC__ASSERT(0 != iterator);
1690         FLAC__ASSERT(0 != iterator->current);
1691         FLAC__ASSERT(0 != block);
1692
1693         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1694                 return false;
1695
1696         if(0 == iterator->current->prev) {
1697                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1698                 return false;
1699         }
1700
1701         if(0 == (node = node_new_()))
1702                 return false;
1703
1704         node->data = block;
1705         iterator_insert_node_(iterator, node);
1706         iterator->current = node;
1707         return true;
1708 }
1709
1710 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_after(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1711 {
1712         FLAC__Metadata_Node *node;
1713
1714         FLAC__ASSERT(0 != iterator);
1715         FLAC__ASSERT(0 != iterator->current);
1716         FLAC__ASSERT(0 != block);
1717
1718         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1719                 return false;
1720
1721         if(0 == (node = node_new_()))
1722                 return false;
1723
1724         node->data = block;
1725         iterator_insert_node_after_(iterator, node);
1726         iterator->current = node;
1727         return true;
1728 }
1729
1730
1731 /****************************************************************************
1732  *
1733  * Local function definitions
1734  *
1735  ***************************************************************************/
1736
1737 void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
1738 {
1739         unsigned i;
1740
1741         b += bytes;
1742
1743         for(i = 0; i < bytes; i++) {
1744                 *(--b) = (FLAC__byte)(val & 0xff);
1745                 val >>= 8;
1746         }
1747 }
1748
1749 void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
1750 {
1751         unsigned i;
1752
1753         for(i = 0; i < bytes; i++) {
1754                 *(b++) = (FLAC__byte)(val & 0xff);
1755                 val >>= 8;
1756         }
1757 }
1758
1759 void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes)
1760 {
1761         unsigned i;
1762
1763         b += bytes;
1764
1765         for(i = 0; i < bytes; i++) {
1766                 *(--b) = (FLAC__byte)(val & 0xff);
1767                 val >>= 8;
1768         }
1769 }
1770
1771 FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes)
1772 {
1773         FLAC__uint32 ret = 0;
1774         unsigned i;
1775
1776         for(i = 0; i < bytes; i++)
1777                 ret = (ret << 8) | (FLAC__uint32)(*b++);
1778
1779         return ret;
1780 }
1781
1782 FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes)
1783 {
1784         FLAC__uint32 ret = 0;
1785         unsigned i;
1786
1787         b += bytes;
1788
1789         for(i = 0; i < bytes; i++)
1790                 ret = (ret << 8) | (FLAC__uint32)(*--b);
1791
1792         return ret;
1793 }
1794
1795 FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes)
1796 {
1797         FLAC__uint64 ret = 0;
1798         unsigned i;
1799
1800         for(i = 0; i < bytes; i++)
1801                 ret = (ret << 8) | (FLAC__uint64)(*b++);
1802
1803         return ret;
1804 }
1805
1806 FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator)
1807 {
1808         FLAC__ASSERT(0 != iterator);
1809         FLAC__ASSERT(0 != iterator->file);
1810
1811         if(!read_metadata_block_header_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, &iterator->is_last, &iterator->type, &iterator->length)) {
1812                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1813                 return false;
1814         }
1815
1816         return true;
1817 }
1818
1819 FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block)
1820 {
1821         FLAC__ASSERT(0 != iterator);
1822         FLAC__ASSERT(0 != iterator->file);
1823
1824         iterator->status = read_metadata_block_data_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, block);
1825
1826         return (iterator->status == FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK);
1827 }
1828
1829 FLAC__bool read_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__bool *is_last, FLAC__MetadataType *type, unsigned *length)
1830 {
1831         FLAC__byte raw_header[FLAC__STREAM_METADATA_HEADER_LENGTH];
1832
1833         if(read_cb(raw_header, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
1834                 return false;
1835
1836         *is_last = raw_header[0] & 0x80? true : false;
1837         *type = (FLAC__MetadataType)(raw_header[0] & 0x7f);
1838         *length = unpack_uint32_(raw_header + 1, 3);
1839
1840         /* Note that we don't check:
1841          *    if(iterator->type >= FLAC__METADATA_TYPE_UNDEFINED)
1842          * we just will read in an opaque block
1843          */
1844
1845         return true;
1846 }
1847
1848 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata *block)
1849 {
1850         switch(block->type) {
1851                 case FLAC__METADATA_TYPE_STREAMINFO:
1852                         return read_metadata_block_data_streaminfo_cb_(handle, read_cb, &block->data.stream_info);
1853                 case FLAC__METADATA_TYPE_PADDING:
1854                         return read_metadata_block_data_padding_cb_(handle, seek_cb, &block->data.padding, block->length);
1855                 case FLAC__METADATA_TYPE_APPLICATION:
1856                         return read_metadata_block_data_application_cb_(handle, read_cb, &block->data.application, block->length);
1857                 case FLAC__METADATA_TYPE_SEEKTABLE:
1858                         return read_metadata_block_data_seektable_cb_(handle, read_cb, &block->data.seek_table, block->length);
1859                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
1860                         return read_metadata_block_data_vorbis_comment_cb_(handle, read_cb, &block->data.vorbis_comment);
1861                 case FLAC__METADATA_TYPE_CUESHEET:
1862                         return read_metadata_block_data_cuesheet_cb_(handle, read_cb, &block->data.cue_sheet);
1863                 default:
1864                         return read_metadata_block_data_unknown_cb_(handle, read_cb, &block->data.unknown, block->length);
1865         }
1866 }
1867
1868 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_StreamInfo *block)
1869 {
1870         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH], *b;
1871
1872         if(read_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
1873                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1874
1875         b = buffer;
1876
1877         /* we are using hardcoded numbers for simplicity but we should
1878          * probably eventually write a bit-level unpacker and use the
1879          * _STREAMINFO_ constants.
1880          */
1881         block->min_blocksize = unpack_uint32_(b, 2); b += 2;
1882         block->max_blocksize = unpack_uint32_(b, 2); b += 2;
1883         block->min_framesize = unpack_uint32_(b, 3); b += 3;
1884         block->max_framesize = unpack_uint32_(b, 3); b += 3;
1885         block->sample_rate = (unpack_uint32_(b, 2) << 4) | ((unsigned)(b[2] & 0xf0) >> 4);
1886         block->channels = (unsigned)((b[2] & 0x0e) >> 1) + 1;
1887         block->bits_per_sample = ((((unsigned)(b[2] & 0x01)) << 4) | (((unsigned)(b[3] & 0xf0)) >> 4)) + 1;
1888         block->total_samples = (((FLAC__uint64)(b[3] & 0x0f)) << 32) | unpack_uint64_(b+4, 4);
1889         memcpy(block->md5sum, b+8, 16);
1890
1891         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1892 }
1893
1894
1895 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata_Padding *block, unsigned block_length)
1896 {
1897         (void)block; /* nothing to do; we don't care about reading the padding bytes */
1898
1899         if(0 != seek_cb(handle, block_length, SEEK_CUR))
1900                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
1901
1902         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1903 }
1904
1905 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Application *block, unsigned block_length)
1906 {
1907         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
1908
1909         if(read_cb(block->id, 1, id_bytes, handle) != id_bytes)
1910                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1911
1912         block_length -= id_bytes;
1913
1914         if(block_length == 0) {
1915                 block->data = 0;
1916         }
1917         else {
1918                 if(0 == (block->data = (FLAC__byte*)malloc(block_length)))
1919                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
1920
1921                 if(read_cb(block->data, 1, block_length, handle) != block_length)
1922                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1923         }
1924
1925         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1926 }
1927
1928 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_SeekTable *block, unsigned block_length)
1929 {
1930         unsigned i;
1931         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
1932
1933         FLAC__ASSERT(block_length % FLAC__STREAM_METADATA_SEEKPOINT_LENGTH == 0);
1934
1935         block->num_points = block_length / FLAC__STREAM_METADATA_SEEKPOINT_LENGTH;
1936
1937         if(block->num_points == 0)
1938                 block->points = 0;
1939         else if(0 == (block->points = (FLAC__StreamMetadata_SeekPoint*)malloc(block->num_points * sizeof(FLAC__StreamMetadata_SeekPoint))))
1940                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
1941
1942         for(i = 0; i < block->num_points; i++) {
1943                 if(read_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
1944                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1945                 /* some MAGIC NUMBERs here */
1946                 block->points[i].sample_number = unpack_uint64_(buffer, 8);
1947                 block->points[i].stream_offset = unpack_uint64_(buffer+8, 8);
1948                 block->points[i].frame_samples = unpack_uint32_(buffer+16, 2);
1949         }
1950
1951         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1952 }
1953
1954 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_entry_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment_Entry *entry)
1955 {
1956         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
1957         FLAC__byte buffer[4]; /* magic number is asserted below */
1958
1959         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8 == 4);
1960
1961         if(read_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
1962                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1963         entry->length = unpack_uint32_little_endian_(buffer, entry_length_len);
1964
1965         if(0 != entry->entry)
1966                 free(entry->entry);
1967
1968         if(entry->length == 0) {
1969                 entry->entry = 0;
1970         }
1971         else {
1972                 if(0 == (entry->entry = (FLAC__byte*)malloc(entry->length)))
1973                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
1974
1975                 if(read_cb(entry->entry, 1, entry->length, handle) != entry->length)
1976                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1977         }
1978
1979         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1980 }
1981
1982 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment *block)
1983 {
1984         unsigned i;
1985         FLAC__Metadata_SimpleIteratorStatus status;
1986         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
1987         FLAC__byte buffer[4]; /* magic number is asserted below */
1988
1989         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8 == 4);
1990
1991         if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, &(block->vendor_string))))
1992                 return status;
1993
1994         if(read_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
1995                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1996         block->num_comments = unpack_uint32_little_endian_(buffer, num_comments_len);
1997
1998         if(block->num_comments == 0) {
1999                 block->comments = 0;
2000         }
2001         else if(0 == (block->comments = (FLAC__StreamMetadata_VorbisComment_Entry*)calloc(block->num_comments, sizeof(FLAC__StreamMetadata_VorbisComment_Entry))))
2002                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2003
2004         for(i = 0; i < block->num_comments; i++) {
2005                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, block->comments + i)))
2006                         return status;
2007         }
2008
2009         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2010 }
2011
2012 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet_Track *track)
2013 {
2014         unsigned i, len;
2015         FLAC__byte buffer[32]; /* asserted below that this is big enough */
2016
2017         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2018         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2019         FLAC__ASSERT(sizeof(buffer) >= (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8);
2020
2021         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2022         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2023         if(read_cb(buffer, 1, len, handle) != len)
2024                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2025         track->offset = unpack_uint64_(buffer, len);
2026
2027         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2028         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2029         if(read_cb(buffer, 1, len, handle) != len)
2030                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2031         track->number = (FLAC__byte)unpack_uint32_(buffer, len);
2032
2033         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2034         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2035         if(read_cb(track->isrc, 1, len, handle) != len)
2036                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2037
2038         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) % 8 == 0);
2039         len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2040         if(read_cb(buffer, 1, len, handle) != len)
2041                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2042         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN == 1);
2043         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN == 1);
2044         track->type = buffer[0] >> 7;
2045         track->pre_emphasis = (buffer[0] >> 6) & 1;
2046
2047         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2048         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2049         if(read_cb(buffer, 1, len, handle) != len)
2050                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2051         track->num_indices = (FLAC__byte)unpack_uint32_(buffer, len);
2052
2053         if(track->num_indices == 0) {
2054                 track->indices = 0;
2055         }
2056         else if(0 == (track->indices = (FLAC__StreamMetadata_CueSheet_Index*)calloc(track->num_indices, sizeof(FLAC__StreamMetadata_CueSheet_Index))))
2057                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2058
2059         for(i = 0; i < track->num_indices; i++) {
2060                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2061                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2062                 if(read_cb(buffer, 1, len, handle) != len)
2063                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2064                 track->indices[i].offset = unpack_uint64_(buffer, len);
2065
2066                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2067                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2068                 if(read_cb(buffer, 1, len, handle) != len)
2069                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2070                 track->indices[i].number = (FLAC__byte)unpack_uint32_(buffer, len);
2071
2072                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2073                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2074                 if(read_cb(buffer, 1, len, handle) != len)
2075                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2076         }
2077
2078         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2079 }
2080
2081 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet *block)
2082 {
2083         unsigned i, len;
2084         FLAC__Metadata_SimpleIteratorStatus status;
2085         FLAC__byte buffer[1024]; /* MSVC needs a constant expression so we put a magic number and assert */
2086
2087         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN)/8 <= sizeof(buffer));
2088         FLAC__ASSERT(sizeof(FLAC__uint64) <= sizeof(buffer));
2089
2090         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2091         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2092         if(read_cb(block->media_catalog_number, 1, len, handle) != len)
2093                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2094
2095         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2096         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2097         if(read_cb(buffer, 1, len, handle) != len)
2098                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2099         block->lead_in = unpack_uint64_(buffer, len);
2100
2101         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2102         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2103         if(read_cb(buffer, 1, len, handle) != len)
2104                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2105         block->is_cd = buffer[0]&0x80? true : false;
2106
2107         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2108         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2109         if(read_cb(buffer, 1, len, handle) != len)
2110                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2111         block->num_tracks = unpack_uint32_(buffer, len);
2112
2113         if(block->num_tracks == 0) {
2114                 block->tracks = 0;
2115         }
2116         else if(0 == (block->tracks = (FLAC__StreamMetadata_CueSheet_Track*)calloc(block->num_tracks, sizeof(FLAC__StreamMetadata_CueSheet_Track))))
2117                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2118
2119         for(i = 0; i < block->num_tracks; i++) {
2120                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_cuesheet_track_cb_(handle, read_cb, block->tracks + i)))
2121                         return status;
2122         }
2123
2124         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2125 }
2126
2127 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2128 {
2129         if(block_length == 0) {
2130                 block->data = 0;
2131         }
2132         else {
2133                 if(0 == (block->data = (FLAC__byte*)malloc(block_length)))
2134                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2135
2136                 if(read_cb(block->data, 1, block_length, handle) != block_length)
2137                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2138         }
2139
2140         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2141 }
2142
2143 FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2144 {
2145         FLAC__ASSERT(0 != file);
2146         FLAC__ASSERT(0 != status);
2147
2148         if(!write_metadata_block_header_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2149                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2150                 return false;
2151         }
2152
2153         return true;
2154 }
2155
2156 FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2157 {
2158         FLAC__ASSERT(0 != file);
2159         FLAC__ASSERT(0 != status);
2160
2161         if (write_metadata_block_data_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2162                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2163                 return true;
2164         }
2165         else {
2166                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2167                 return false;
2168         }
2169 }
2170
2171 FLAC__bool write_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2172 {
2173         FLAC__byte buffer[FLAC__STREAM_METADATA_HEADER_LENGTH];
2174
2175         FLAC__ASSERT(block->length < (1u << FLAC__STREAM_METADATA_LENGTH_LEN));
2176
2177         buffer[0] = (block->is_last? 0x80 : 0) | (FLAC__byte)block->type;
2178         pack_uint32_(block->length, buffer + 1, 3);
2179
2180         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
2181                 return false;
2182
2183         return true;
2184 }
2185
2186 FLAC__bool write_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2187 {
2188         FLAC__ASSERT(0 != block);
2189
2190         switch(block->type) {
2191                 case FLAC__METADATA_TYPE_STREAMINFO:
2192                         return write_metadata_block_data_streaminfo_cb_(handle, write_cb, &block->data.stream_info);
2193                 case FLAC__METADATA_TYPE_PADDING:
2194                         return write_metadata_block_data_padding_cb_(handle, write_cb, &block->data.padding, block->length);
2195                 case FLAC__METADATA_TYPE_APPLICATION:
2196                         return write_metadata_block_data_application_cb_(handle, write_cb, &block->data.application, block->length);
2197                 case FLAC__METADATA_TYPE_SEEKTABLE:
2198                         return write_metadata_block_data_seektable_cb_(handle, write_cb, &block->data.seek_table);
2199                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
2200                         return write_metadata_block_data_vorbis_comment_cb_(handle, write_cb, &block->data.vorbis_comment);
2201                 case FLAC__METADATA_TYPE_CUESHEET:
2202                         return write_metadata_block_data_cuesheet_cb_(handle, write_cb, &block->data.cue_sheet);
2203                 default:
2204                         return write_metadata_block_data_unknown_cb_(handle, write_cb, &block->data.unknown, block->length);
2205         }
2206 }
2207
2208 FLAC__bool write_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_StreamInfo *block)
2209 {
2210         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH];
2211         const unsigned channels1 = block->channels - 1;
2212         const unsigned bps1 = block->bits_per_sample - 1;
2213
2214         /* we are using hardcoded numbers for simplicity but we should
2215          * probably eventually write a bit-level packer and use the
2216          * _STREAMINFO_ constants.
2217          */
2218         pack_uint32_(block->min_blocksize, buffer, 2);
2219         pack_uint32_(block->max_blocksize, buffer+2, 2);
2220         pack_uint32_(block->min_framesize, buffer+4, 3);
2221         pack_uint32_(block->max_framesize, buffer+7, 3);
2222         buffer[10] = (block->sample_rate >> 12) & 0xff;
2223         buffer[11] = (block->sample_rate >> 4) & 0xff;
2224         buffer[12] = ((block->sample_rate & 0x0f) << 4) | (channels1 << 1) | (bps1 >> 4);
2225         buffer[13] = (FLAC__byte)(((bps1 & 0x0f) << 4) | ((block->total_samples >> 32) & 0x0f));
2226         pack_uint32_((FLAC__uint32)block->total_samples, buffer+14, 4);
2227         memcpy(buffer+18, block->md5sum, 16);
2228
2229         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
2230                 return false;
2231
2232         return true;
2233 }
2234
2235 FLAC__bool write_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Padding *block, unsigned block_length)
2236 {
2237         unsigned i, n = block_length;
2238         FLAC__byte buffer[1024];
2239
2240         (void)block;
2241
2242         memset(buffer, 0, 1024);
2243
2244         for(i = 0; i < n/1024; i++)
2245                 if(write_cb(buffer, 1, 1024, handle) != 1024)
2246                         return false;
2247
2248         n %= 1024;
2249
2250         if(write_cb(buffer, 1, n, handle) != n)
2251                 return false;
2252
2253         return true;
2254 }
2255
2256 FLAC__bool write_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Application *block, unsigned block_length)
2257 {
2258         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
2259
2260         if(write_cb(block->id, 1, id_bytes, handle) != id_bytes)
2261                 return false;
2262
2263         block_length -= id_bytes;
2264
2265         if(write_cb(block->data, 1, block_length, handle) != block_length)
2266                 return false;
2267
2268         return true;
2269 }
2270
2271 FLAC__bool write_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_SeekTable *block)
2272 {
2273         unsigned i;
2274         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
2275
2276         for(i = 0; i < block->num_points; i++) {
2277                 /* some MAGIC NUMBERs here */
2278                 pack_uint64_(block->points[i].sample_number, buffer, 8);
2279                 pack_uint64_(block->points[i].stream_offset, buffer+8, 8);
2280                 pack_uint32_(block->points[i].frame_samples, buffer+16, 2);
2281                 if(write_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
2282                         return false;
2283         }
2284
2285         return true;
2286 }
2287
2288 FLAC__bool write_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_VorbisComment *block)
2289 {
2290         unsigned i;
2291         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
2292         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2293         FLAC__byte buffer[4]; /* magic number is asserted below */
2294
2295         FLAC__ASSERT(max(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN, FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN) / 8 == 4);
2296
2297         pack_uint32_little_endian_(block->vendor_string.length, buffer, entry_length_len);
2298         if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2299                 return false;
2300         if(write_cb(block->vendor_string.entry, 1, block->vendor_string.length, handle) != block->vendor_string.length)
2301                 return false;
2302
2303         pack_uint32_little_endian_(block->num_comments, buffer, num_comments_len);
2304         if(write_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2305                 return false;
2306
2307         for(i = 0; i < block->num_comments; i++) {
2308                 pack_uint32_little_endian_(block->comments[i].length, buffer, entry_length_len);
2309                 if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2310                         return false;
2311                 if(write_cb(block->comments[i].entry, 1, block->comments[i].length, handle) != block->comments[i].length)
2312                         return false;
2313         }
2314
2315         return true;
2316 }
2317
2318 FLAC__bool write_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_CueSheet *block)
2319 {
2320         unsigned i, j, len;
2321         FLAC__byte buffer[1024]; /* asserted below that this is big enough */
2322
2323         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2324         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN/8);
2325         FLAC__ASSERT(sizeof(buffer) >= (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN)/8);
2326         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2327
2328         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2329         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2330         if(write_cb(block->media_catalog_number, 1, len, handle) != len)
2331                 return false;
2332
2333         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2334         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2335         pack_uint64_(block->lead_in, buffer, len);
2336         if(write_cb(buffer, 1, len, handle) != len)
2337                 return false;
2338
2339         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2340         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2341         memset(buffer, 0, len);
2342         if(block->is_cd)
2343                 buffer[0] |= 0x80;
2344         if(write_cb(buffer, 1, len, handle) != len)
2345                 return false;
2346
2347         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2348         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2349         pack_uint32_(block->num_tracks, buffer, len);
2350         if(write_cb(buffer, 1, len, handle) != len)
2351                 return false;
2352
2353         for(i = 0; i < block->num_tracks; i++) {
2354                 FLAC__StreamMetadata_CueSheet_Track *track = block->tracks + i;
2355
2356                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2357                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2358                 pack_uint64_(track->offset, buffer, len);
2359                 if(write_cb(buffer, 1, len, handle) != len)
2360                         return false;
2361
2362                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2363                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2364                 pack_uint32_(track->number, buffer, len);
2365                 if(write_cb(buffer, 1, len, handle) != len)
2366                         return false;
2367
2368                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2369                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2370                 if(write_cb(track->isrc, 1, len, handle) != len)
2371                         return false;
2372
2373                 FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) % 8 == 0);
2374                 len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2375                 memset(buffer, 0, len);
2376                 buffer[0] = (track->type << 7) | (track->pre_emphasis << 6);
2377                 if(write_cb(buffer, 1, len, handle) != len)
2378                         return false;
2379
2380                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2381                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2382                 pack_uint32_(track->num_indices, buffer, len);
2383                 if(write_cb(buffer, 1, len, handle) != len)
2384                         return false;
2385
2386                 for(j = 0; j < track->num_indices; j++) {
2387                         FLAC__StreamMetadata_CueSheet_Index *index = track->indices + j;
2388
2389                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2390                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2391                         pack_uint64_(index->offset, buffer, len);
2392                         if(write_cb(buffer, 1, len, handle) != len)
2393                                 return false;
2394
2395                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2396                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2397                         pack_uint32_(index->number, buffer, len);
2398                         if(write_cb(buffer, 1, len, handle) != len)
2399                                 return false;
2400
2401                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2402                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2403                         memset(buffer, 0, len);
2404                         if(write_cb(buffer, 1, len, handle) != len)
2405                                 return false;
2406                 }
2407         }
2408
2409         return true;
2410 }
2411
2412 FLAC__bool write_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2413 {
2414         if(write_cb(block->data, 1, block_length, handle) != block_length)
2415                 return false;
2416
2417         return true;
2418 }
2419
2420 FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block)
2421 {
2422         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2423                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2424                 return false;
2425         }
2426
2427         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2428                 return false;
2429
2430         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2431                 return false;
2432
2433         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2434                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2435                 return false;
2436         }
2437
2438         return read_metadata_block_header_(iterator);
2439 }
2440
2441 FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last)
2442 {
2443         FLAC__StreamMetadata *padding;
2444
2445         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2446                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2447                 return false;
2448         }
2449
2450         block->is_last = false;
2451
2452         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2453                 return false;
2454
2455         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2456                 return false;
2457
2458         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING)))
2459                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2460
2461         padding->is_last = padding_is_last;
2462         padding->length = padding_length;
2463
2464         if(!write_metadata_block_header_(iterator->file, &iterator->status, padding)) {
2465                 FLAC__metadata_object_delete(padding);
2466                 return false;
2467         }
2468
2469         if(!write_metadata_block_data_(iterator->file, &iterator->status, padding)) {
2470                 FLAC__metadata_object_delete(padding);
2471                 return false;
2472         }
2473
2474         FLAC__metadata_object_delete(padding);
2475
2476         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2477                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2478                 return false;
2479         }
2480
2481         return read_metadata_block_header_(iterator);
2482 }
2483
2484 FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append)
2485 {
2486         FILE *tempfile;
2487         char *tempfilename;
2488         int fixup_is_last_code = 0; /* 0 => no need to change any is_last flags */
2489         long fixup_is_last_flag_offset = -1;
2490
2491         FLAC__ASSERT(0 != block || append == false);
2492
2493         if(iterator->is_last) {
2494                 if(append) {
2495                         fixup_is_last_code = 1; /* 1 => clear the is_last flag at the following offset */
2496                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2497                 }
2498                 else if(0 == block) {
2499                         simple_iterator_push_(iterator);
2500                         if(!FLAC__metadata_simple_iterator_prev(iterator)) {
2501                                 (void)simple_iterator_pop_(iterator);
2502                                 return false;
2503                         }
2504                         fixup_is_last_code = -1; /* -1 => set the is_last the flag at the following offset */
2505                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2506                         if(!simple_iterator_pop_(iterator))
2507                                 return false;
2508                 }
2509         }
2510
2511         if(!simple_iterator_copy_file_prefix_(iterator, &tempfile, &tempfilename, append))
2512                 return false;
2513
2514         if(0 != block) {
2515                 if(!write_metadata_block_header_(tempfile, &iterator->status, block)) {
2516                         cleanup_tempfile_(&tempfile, &tempfilename);
2517                         return false;
2518                 }
2519
2520                 if(!write_metadata_block_data_(tempfile, &iterator->status, block)) {
2521                         cleanup_tempfile_(&tempfile, &tempfilename);
2522                         return false;
2523                 }
2524         }
2525
2526         if(!simple_iterator_copy_file_postfix_(iterator, &tempfile, &tempfilename, fixup_is_last_code, fixup_is_last_flag_offset, block==0))
2527                 return false;
2528
2529         if(append)
2530                 return FLAC__metadata_simple_iterator_next(iterator);
2531
2532         return true;
2533 }
2534
2535 void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator)
2536 {
2537         FLAC__ASSERT(iterator->depth+1 < SIMPLE_ITERATOR_MAX_PUSH_DEPTH);
2538         iterator->offset[iterator->depth+1] = iterator->offset[iterator->depth];
2539         iterator->depth++;
2540 }
2541
2542 FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator)
2543 {
2544         FLAC__ASSERT(iterator->depth > 0);
2545         iterator->depth--;
2546         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2547                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2548                 return false;
2549         }
2550
2551         return read_metadata_block_header_(iterator);
2552 }
2553
2554 /* return meanings:
2555  * 0: ok
2556  * 1: read error
2557  * 2: seek error
2558  * 3: not a FLAC file
2559  */
2560 unsigned seek_to_first_metadata_block_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb)
2561 {
2562         FLAC__byte buffer[4];
2563         size_t n;
2564         unsigned i;
2565
2566         FLAC__ASSERT(FLAC__STREAM_SYNC_LENGTH == 4);
2567
2568         /* skip any id3v2 tag */
2569         errno = 0;
2570         n = read_cb(buffer, 1, 4, handle);
2571         if(errno)
2572                 return 1;
2573         else if(n != 4)
2574                 return 3;
2575         else if(0 == memcmp(buffer, "ID3", 3)) {
2576                 unsigned tag_length = 0;
2577
2578                 /* skip to the tag length */
2579                 if(seek_cb(handle, 2, SEEK_CUR) < 0)
2580                         return 2;
2581
2582                 /* read the length */
2583                 for(i = 0; i < 4; i++) {
2584                         if(read_cb(buffer, 1, 1, handle) < 1 || buffer[0] & 0x80)
2585                                 return 1;
2586                         tag_length <<= 7;
2587                         tag_length |= (buffer[0] & 0x7f);
2588                 }
2589
2590                 /* skip the rest of the tag */
2591                 if(seek_cb(handle, tag_length, SEEK_CUR) < 0)
2592                         return 2;
2593
2594                 /* read the stream sync code */
2595                 errno = 0;
2596                 n = read_cb(buffer, 1, 4, handle);
2597                 if(errno)
2598                         return 1;
2599                 else if(n != 4)
2600                         return 3;
2601         }
2602
2603         /* check for the fLaC signature */
2604         if(0 == memcmp(FLAC__STREAM_SYNC_STRING, buffer, FLAC__STREAM_SYNC_LENGTH))
2605                 return 0;
2606         else
2607                 return 3;
2608 }
2609
2610 unsigned seek_to_first_metadata_block_(FILE *f)
2611 {
2612         return seek_to_first_metadata_block_cb_((FLAC__IOHandle)f, (FLAC__IOCallback_Read)fread, fseek_wrapper_);
2613 }
2614
2615 FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append)
2616 {
2617         const long offset_end = append? iterator->offset[iterator->depth] + (long)FLAC__STREAM_METADATA_HEADER_LENGTH + (long)iterator->length : iterator->offset[iterator->depth];
2618
2619         if(0 != fseek(iterator->file, 0, SEEK_SET)) {
2620                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2621                 return false;
2622         }
2623         if(!open_tempfile_(iterator->filename, iterator->tempfile_path_prefix, tempfile, tempfilename, &iterator->status)) {
2624                 cleanup_tempfile_(tempfile, tempfilename);
2625                 return false;
2626         }
2627         if(!copy_n_bytes_from_file_(iterator->file, *tempfile, offset_end, &iterator->status)) {
2628                 cleanup_tempfile_(tempfile, tempfilename);
2629                 return false;
2630         }
2631
2632         return true;
2633 }
2634
2635 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)
2636 {
2637         long save_offset = iterator->offset[iterator->depth]; /*@@@ 2G limit */
2638         FLAC__ASSERT(0 != *tempfile);
2639
2640         if(0 != fseek(iterator->file, save_offset + FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length, SEEK_SET)) {
2641                 cleanup_tempfile_(tempfile, tempfilename);
2642                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2643                 return false;
2644         }
2645         if(!copy_remaining_bytes_from_file_(iterator->file, *tempfile, &iterator->status)) {
2646                 cleanup_tempfile_(tempfile, tempfilename);
2647                 return false;
2648         }
2649
2650         if(fixup_is_last_code != 0) {
2651                 /*
2652                  * if code == 1, it means a block was appended to the end so
2653                  *   we have to clear the is_last flag of the previous block
2654                  * if code == -1, it means the last block was deleted so
2655                  *   we have to set the is_last flag of the previous block
2656                  */
2657                 /* MAGIC NUMBERs here; we know the is_last flag is the high bit of the byte at this location */
2658                 FLAC__byte x;
2659                 if(0 != fseek(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
2660                         cleanup_tempfile_(tempfile, tempfilename);
2661                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2662                         return false;
2663                 }
2664                 if(fread(&x, 1, 1, *tempfile) != 1) {
2665                         cleanup_tempfile_(tempfile, tempfilename);
2666                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2667                         return false;
2668                 }
2669                 if(fixup_is_last_code > 0) {
2670                         FLAC__ASSERT(x & 0x80);
2671                         x &= 0x7f;
2672                 }
2673                 else {
2674                         FLAC__ASSERT(!(x & 0x80));
2675                         x |= 0x80;
2676                 }
2677                 if(0 != fseek(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
2678                         cleanup_tempfile_(tempfile, tempfilename);
2679                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2680                         return false;
2681                 }
2682                 if(local__fwrite(&x, 1, 1, *tempfile) != 1) {
2683                         cleanup_tempfile_(tempfile, tempfilename);
2684                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2685                         return false;
2686                 }
2687         }
2688
2689         (void)fclose(iterator->file);
2690
2691         if(!transport_tempfile_(iterator->filename, tempfile, tempfilename, &iterator->status))
2692                 return false;
2693
2694         if(iterator->has_stats)
2695                 set_file_stats_(iterator->filename, &iterator->stats);
2696
2697         if(!simple_iterator_prime_input_(iterator, !iterator->is_writable))
2698                 return false;
2699         if(backup) {
2700                 while(iterator->offset[iterator->depth] + (long)FLAC__STREAM_METADATA_HEADER_LENGTH + (long)iterator->length < save_offset)
2701                         if(!FLAC__metadata_simple_iterator_next(iterator))
2702                                 return false;
2703                 return true;
2704         }
2705         else {
2706                 /* move the iterator to it's original block faster by faking a push, then doing a pop_ */
2707                 FLAC__ASSERT(iterator->depth == 0);
2708                 iterator->offset[0] = save_offset;
2709                 iterator->depth++;
2710                 return simple_iterator_pop_(iterator);
2711         }
2712 }
2713
2714 FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, unsigned bytes/*@@@ 4G limit*/, FLAC__Metadata_SimpleIteratorStatus *status)
2715 {
2716         FLAC__byte buffer[8192];
2717         unsigned n;
2718
2719         while(bytes > 0) {
2720                 n = min(sizeof(buffer), bytes);
2721                 if(fread(buffer, 1, n, file) != n) {
2722                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2723                         return false;
2724                 }
2725                 if(local__fwrite(buffer, 1, n, tempfile) != n) {
2726                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2727                         return false;
2728                 }
2729                 bytes -= n;
2730         }
2731
2732         return true;
2733 }
2734
2735 FLAC__bool copy_n_bytes_from_file_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOHandle temp_handle, FLAC__IOCallback_Write temp_write_cb, unsigned bytes/*@@@ 4G limit*/, FLAC__Metadata_SimpleIteratorStatus *status)
2736 {
2737         FLAC__byte buffer[8192];
2738         unsigned n;
2739
2740         while(bytes > 0) {
2741                 n = min(sizeof(buffer), bytes);
2742                 if(read_cb(buffer, 1, n, handle) != n) {
2743                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2744                         return false;
2745                 }
2746                 if(temp_write_cb(buffer, 1, n, temp_handle) != n) {
2747                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2748                         return false;
2749                 }
2750                 bytes -= n;
2751         }
2752
2753         return true;
2754 }
2755
2756 FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status)
2757 {
2758         FLAC__byte buffer[8192];
2759         size_t n;
2760
2761         while(!feof(file)) {
2762                 n = fread(buffer, 1, sizeof(buffer), file);
2763                 if(n == 0 && !feof(file)) {
2764                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2765                         return false;
2766                 }
2767                 if(n > 0 && local__fwrite(buffer, 1, n, tempfile) != n) {
2768                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2769                         return false;
2770                 }
2771         }
2772
2773         return true;
2774 }
2775
2776 FLAC__bool copy_remaining_bytes_from_file_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Eof eof_cb, FLAC__IOHandle temp_handle, FLAC__IOCallback_Write temp_write_cb, FLAC__Metadata_SimpleIteratorStatus *status)
2777 {
2778         FLAC__byte buffer[8192];
2779         size_t n;
2780
2781         while(!eof_cb(handle)) {
2782                 n = read_cb(buffer, 1, sizeof(buffer), handle);
2783                 if(n == 0 && !eof_cb(handle)) {
2784                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2785                         return false;
2786                 }
2787                 if(n > 0 && temp_write_cb(buffer, 1, n, temp_handle) != n) {
2788                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2789                         return false;
2790                 }
2791         }
2792
2793         return true;
2794 }
2795
2796 FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
2797 {
2798         static const char *tempfile_suffix = ".metadata_edit";
2799         if(0 == tempfile_path_prefix) {
2800                 if(0 == (*tempfilename = (char*)malloc(strlen(filename) + strlen(tempfile_suffix) + 1))) {
2801                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2802                         return false;
2803                 }
2804                 strcpy(*tempfilename, filename);
2805                 strcat(*tempfilename, tempfile_suffix);
2806         }
2807         else {
2808                 const char *p = strrchr(filename, '/');
2809                 if(0 == p)
2810                         p = filename;
2811                 else
2812                         p++;
2813
2814                 if(0 == (*tempfilename = (char*)malloc(strlen(tempfile_path_prefix) + 1 + strlen(p) + strlen(tempfile_suffix) + 1))) {
2815                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2816                         return false;
2817                 }
2818                 strcpy(*tempfilename, tempfile_path_prefix);
2819                 strcat(*tempfilename, "/");
2820                 strcat(*tempfilename, p);
2821                 strcat(*tempfilename, tempfile_suffix);
2822         }
2823
2824         if(0 == (*tempfile = fopen(*tempfilename, "w+b"))) {
2825                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
2826                 return false;
2827         }
2828
2829         return true;
2830 }
2831
2832 FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
2833 {
2834         FLAC__ASSERT(0 != filename);
2835         FLAC__ASSERT(0 != tempfile);
2836         FLAC__ASSERT(0 != *tempfile);
2837         FLAC__ASSERT(0 != tempfilename);
2838         FLAC__ASSERT(0 != *tempfilename);
2839         FLAC__ASSERT(0 != status);
2840
2841         (void)fclose(*tempfile);
2842         *tempfile = 0;
2843
2844 #if defined _MSC_VER || defined __MINGW32__
2845         if(unlink(filename) < 0) {
2846                 cleanup_tempfile_(tempfile, tempfilename);
2847                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR;
2848                 return false;
2849         }
2850 #endif
2851
2852         /*@@@ to fully support the tempfile_path_prefix we need to update this piece to actually copy across filesystems instead of just rename(): */
2853         if(0 != rename(*tempfilename, filename)) {
2854                 cleanup_tempfile_(tempfile, tempfilename);
2855                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR;
2856                 return false;
2857         }
2858
2859         cleanup_tempfile_(tempfile, tempfilename);
2860
2861         return true;
2862 }
2863
2864 void cleanup_tempfile_(FILE **tempfile, char **tempfilename)
2865 {
2866         if(0 != *tempfile) {
2867                 (void)fclose(*tempfile);
2868                 *tempfile = 0;
2869         }
2870
2871         if(0 != *tempfilename) {
2872                 (void)unlink(*tempfilename);
2873                 free(*tempfilename);
2874                 *tempfilename = 0;
2875         }
2876 }
2877
2878 FLAC__bool get_file_stats_(const char *filename, struct stat *stats)
2879 {
2880         FLAC__ASSERT(0 != filename);
2881         FLAC__ASSERT(0 != stats);
2882         return (0 == stat(filename, stats));
2883 }
2884
2885 void set_file_stats_(const char *filename, struct stat *stats)
2886 {
2887         struct utimbuf srctime;
2888
2889         FLAC__ASSERT(0 != filename);
2890         FLAC__ASSERT(0 != stats);
2891
2892         srctime.actime = stats->st_atime;
2893         srctime.modtime = stats->st_mtime;
2894         (void)chmod(filename, stats->st_mode);
2895         (void)utime(filename, &srctime);
2896 #if !defined _MSC_VER && !defined __MINGW32__
2897         (void)chown(filename, stats->st_uid, -1);
2898         (void)chown(filename, -1, stats->st_gid);
2899 #endif
2900 }
2901
2902 /* @@@ WATCHOUT @@@
2903  * We cast FLAC__int64 to long and use fseek()/ftell() because
2904  * none of our operations on metadata is ever likely to go past
2905  * 2 gigabytes.
2906  */
2907 int fseek_wrapper_(FLAC__IOHandle handle, FLAC__int64 offset, int whence)
2908 {
2909         FLAC__ASSERT(offset <= 0x7fffffff);
2910         return fseek((FILE*)handle, (long)offset, whence);
2911 }
2912
2913 FLAC__int64 ftell_wrapper_(FLAC__IOHandle handle)
2914 {
2915         return (long)ftell((FILE*)handle);
2916 }
2917
2918 FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status)
2919 {
2920         switch(status) {
2921                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK:
2922                         return FLAC__METADATA_CHAIN_STATUS_OK;
2923                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT:
2924                         return FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT;
2925                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE:
2926                         return FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
2927                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE:
2928                         return FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE;
2929                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE:
2930                         return FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE;
2931                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA:
2932                         return FLAC__METADATA_CHAIN_STATUS_BAD_METADATA;
2933                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR:
2934                         return FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
2935                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR:
2936                         return FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
2937                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR:
2938                         return FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
2939                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR:
2940                         return FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR;
2941                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR:
2942                         return FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR;
2943                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR:
2944                         return FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
2945                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR:
2946                 default:
2947                         return FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
2948         }
2949 }