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 /* assumes 'handle' is already at beginning of file */
1270 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)
1271 {
1272         FLAC__Metadata_SimpleIteratorStatus status;
1273         const FLAC__Metadata_Node *node;
1274
1275         FLAC__ASSERT(0 != chain);
1276         FLAC__ASSERT(0 == chain->filename);
1277         FLAC__ASSERT(0 != chain->head);
1278
1279         /* copy the file prefix (data up to first metadata block */
1280         if(!copy_n_bytes_from_file_cb_(handle, read_cb, temp_handle, temp_write_cb, chain->first_offset, &status)) {
1281                 chain->status = get_equivalent_status_(status);
1282                 return false;
1283         }
1284
1285         /* write the metadata */
1286         for(node = chain->head; node; node = node->next) {
1287                 if(!write_metadata_block_header_cb_(temp_handle, temp_write_cb, node->data)) {
1288                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1289                         return false;
1290                 }
1291                 if(!write_metadata_block_data_cb_(temp_handle, temp_write_cb, node->data)) {
1292                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1293                         return false;
1294                 }
1295         }
1296         /*FLAC__ASSERT(fflush(), ftell() == chain->last_offset);*/
1297
1298         /* copy the file postfix (everything after the metadata) */
1299         if(0 != seek_cb(handle, chain->last_offset, SEEK_SET)) {
1300                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1301                 return false;
1302         }
1303         if(!copy_remaining_bytes_from_file_cb_(handle, read_cb, eof_cb, temp_handle, temp_write_cb, &status)) {
1304                 chain->status = get_equivalent_status_(status);
1305                 return false;
1306         }
1307
1308         return true;
1309 }
1310
1311 FLAC_API FLAC__Metadata_Chain *FLAC__metadata_chain_new()
1312 {
1313         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)calloc(1, sizeof(FLAC__Metadata_Chain));
1314
1315         if(0 != chain)
1316                 chain_init_(chain);
1317
1318         return chain;
1319 }
1320
1321 FLAC_API void FLAC__metadata_chain_delete(FLAC__Metadata_Chain *chain)
1322 {
1323         FLAC__ASSERT(0 != chain);
1324
1325         chain_clear_(chain);
1326
1327         free(chain);
1328 }
1329
1330 FLAC_API FLAC__Metadata_ChainStatus FLAC__metadata_chain_status(FLAC__Metadata_Chain *chain)
1331 {
1332         FLAC__Metadata_ChainStatus status;
1333
1334         FLAC__ASSERT(0 != chain);
1335
1336         status = chain->status;
1337         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
1338         return status;
1339 }
1340
1341 FLAC_API FLAC__bool FLAC__metadata_chain_read(FLAC__Metadata_Chain *chain, const char *filename)
1342 {
1343         FILE *file;
1344         FLAC__bool ret;
1345
1346         FLAC__ASSERT(0 != chain);
1347         FLAC__ASSERT(0 != filename);
1348
1349         chain_clear_(chain);
1350
1351         if(0 == (chain->filename = strdup(filename))) {
1352                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1353                 return false;
1354         }
1355
1356         if(0 == (file = fopen(filename, "rb"))) {
1357                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1358                 return false;
1359         }
1360
1361         /* chain_read_cb_() sets chain->status for us */
1362         ret = chain_read_cb_(chain, file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, ftell_wrapper_);
1363
1364         fclose(file);
1365
1366         return ret;
1367 }
1368
1369 FLAC_API FLAC__bool FLAC__metadata_chain_read_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1370 {
1371         FLAC__ASSERT(0 != chain);
1372
1373         chain_clear_(chain);
1374
1375         if (0 == callbacks.read || 0 == callbacks.seek || 0 == callbacks.tell) {
1376                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1377                 return false;
1378         }
1379
1380         /* rewind */
1381         if(0 != callbacks.seek(handle, 0, SEEK_SET)) {
1382                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1383                 return false;
1384         }
1385
1386         if(!chain_read_cb_(chain, handle, callbacks.read, callbacks.seek, callbacks.tell))
1387                 return false; /* chain->status is already set by chain_read_cb_ */
1388
1389         return true;
1390 }
1391
1392 FLAC_API FLAC__bool FLAC__metadata_chain_check_if_tempfile_needed(FLAC__Metadata_Chain *chain, FLAC__bool use_padding)
1393 {
1394         /* This does all the same checks that are in chain_prepare_for_write_()
1395          * but doesn't actually alter the chain.  Make sure to update the logic
1396          * here if chain_prepare_for_write_() changes.
1397          */
1398         const unsigned current_length = chain_calculate_length_(chain);
1399
1400         FLAC__ASSERT(0 != chain);
1401
1402         if(use_padding) {
1403                 /* if the metadata shrank and the last block is padding, we just extend the last padding block */
1404                 if(current_length < chain->initial_length && chain->tail->data->type == FLAC__METADATA_TYPE_PADDING)
1405                         return false;
1406                 /* if the metadata shrank more than 4 bytes then there's room to add another padding block */
1407                 else if(current_length + FLAC__STREAM_METADATA_HEADER_LENGTH <= chain->initial_length)
1408                         return false;
1409                 /* 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 */
1410                 else if(current_length > chain->initial_length) {
1411                         const unsigned delta = current_length - chain->initial_length;
1412                         if(chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1413                                 /* if the delta is exactly the size of the last padding block, remove the padding block */
1414                                 if(chain->tail->data->length + FLAC__STREAM_METADATA_HEADER_LENGTH == delta)
1415                                         return false;
1416                                 /* if there is at least 'delta' bytes of padding, trim the padding down */
1417                                 else if(chain->tail->data->length >= delta)
1418                                         return false;
1419                         }
1420                 }
1421         }
1422
1423         return (current_length != chain->initial_length);
1424 }
1425
1426 FLAC_API FLAC__bool FLAC__metadata_chain_write(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__bool preserve_file_stats)
1427 {
1428         struct stat stats;
1429         const char *tempfile_path_prefix = 0;
1430         unsigned current_length;
1431
1432         FLAC__ASSERT(0 != chain);
1433
1434         if (0 == chain->filename) {
1435                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1436                 return false;
1437         }
1438
1439         current_length = chain_prepare_for_write_(chain, use_padding);
1440
1441         /* a return value of 0 means there was an error; chain->status is already set */
1442         if (0 == current_length)
1443                 return false;
1444
1445         if(preserve_file_stats)
1446                 get_file_stats_(chain->filename, &stats);
1447
1448         if(current_length == chain->initial_length) {
1449                 if(!chain_rewrite_metadata_in_place_(chain))
1450                         return false;
1451         }
1452         else {
1453                 if(!chain_rewrite_file_(chain, tempfile_path_prefix))
1454                         return false;
1455
1456                 /* recompute lengths and offsets */
1457                 {
1458                         const FLAC__Metadata_Node *node;
1459                         chain->initial_length = current_length;
1460                         chain->last_offset = chain->first_offset;
1461                         for(node = chain->head; node; node = node->next)
1462                                 chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1463                 }
1464         }
1465
1466         if(preserve_file_stats)
1467                 set_file_stats_(chain->filename, &stats);
1468
1469         return true;
1470 }
1471
1472 FLAC_API FLAC__bool FLAC__metadata_chain_write_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1473 {
1474         unsigned current_length;
1475
1476         FLAC__ASSERT(0 != chain);
1477
1478         if (0 != chain->filename) {
1479                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1480                 return false;
1481         }
1482
1483         if (0 == callbacks.write || 0 == callbacks.seek) {
1484                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1485                 return false;
1486         }
1487
1488         if (FLAC__metadata_chain_check_if_tempfile_needed(chain, use_padding)) {
1489                 chain->status = FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL;
1490                 return false;
1491         }
1492
1493         current_length = chain_prepare_for_write_(chain, use_padding);
1494
1495         /* a return value of 0 means there was an error; chain->status is already set */
1496         if (0 == current_length)
1497                 return false;
1498
1499         FLAC__ASSERT(current_length == chain->initial_length);
1500
1501         return chain_rewrite_metadata_in_place_cb_(chain, handle, callbacks.write, callbacks.seek);
1502 }
1503
1504 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)
1505 {
1506         unsigned current_length;
1507
1508         FLAC__ASSERT(0 != chain);
1509
1510         if (0 != chain->filename) {
1511                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1512                 return false;
1513         }
1514
1515         if (0 == callbacks.read || 0 == callbacks.seek || 0 == callbacks.eof) {
1516                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1517                 return false;
1518         }
1519         if (0 == temp_callbacks.write) {
1520                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1521                 return false;
1522         }
1523
1524         if (!FLAC__metadata_chain_check_if_tempfile_needed(chain, use_padding)) {
1525                 chain->status = FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL;
1526                 return false;
1527         }
1528
1529         current_length = chain_prepare_for_write_(chain, use_padding);
1530
1531         /* a return value of 0 means there was an error; chain->status is already set */
1532         if (0 == current_length)
1533                 return false;
1534
1535         FLAC__ASSERT(current_length != chain->initial_length);
1536
1537         /* rewind */
1538         if(0 != callbacks.seek(handle, 0, SEEK_SET)) {
1539                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1540                 return false;
1541         }
1542
1543         if(!chain_rewrite_file_cb_(chain, handle, callbacks.read, callbacks.seek, callbacks.eof, temp_handle, temp_callbacks.write))
1544                 return false;
1545
1546         /* recompute lengths and offsets */
1547         {
1548                 const FLAC__Metadata_Node *node;
1549                 chain->initial_length = current_length;
1550                 chain->last_offset = chain->first_offset;
1551                 for(node = chain->head; node; node = node->next)
1552                         chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1553         }
1554
1555         return true;
1556 }
1557
1558 FLAC_API void FLAC__metadata_chain_merge_padding(FLAC__Metadata_Chain *chain)
1559 {
1560         FLAC__Metadata_Node *node;
1561
1562         FLAC__ASSERT(0 != chain);
1563
1564         for(node = chain->head; node; ) {
1565                 if(!chain_merge_adjacent_padding_(chain, node))
1566                         node = node->next;
1567         }
1568 }
1569
1570 FLAC_API void FLAC__metadata_chain_sort_padding(FLAC__Metadata_Chain *chain)
1571 {
1572         FLAC__Metadata_Node *node, *save;
1573         unsigned i;
1574
1575         FLAC__ASSERT(0 != chain);
1576
1577         /*
1578          * Don't try and be too smart... this simple algo is good enough for
1579          * the small number of nodes that we deal with.
1580          */
1581         for(i = 0, node = chain->head; i < chain->nodes; i++) {
1582                 if(node->data->type == FLAC__METADATA_TYPE_PADDING) {
1583                         save = node->next;
1584                         chain_remove_node_(chain, node);
1585                         chain_append_node_(chain, node);
1586                         node = save;
1587                 }
1588                 else {
1589                         node = node->next;
1590                 }
1591         }
1592
1593         FLAC__metadata_chain_merge_padding(chain);
1594 }
1595
1596
1597 FLAC_API FLAC__Metadata_Iterator *FLAC__metadata_iterator_new()
1598 {
1599         FLAC__Metadata_Iterator *iterator = (FLAC__Metadata_Iterator*)calloc(1, sizeof(FLAC__Metadata_Iterator));
1600
1601         /* calloc() implies:
1602                 iterator->current = 0;
1603                 iterator->chain = 0;
1604         */
1605
1606         return iterator;
1607 }
1608
1609 FLAC_API void FLAC__metadata_iterator_delete(FLAC__Metadata_Iterator *iterator)
1610 {
1611         FLAC__ASSERT(0 != iterator);
1612
1613         free(iterator);
1614 }
1615
1616 FLAC_API void FLAC__metadata_iterator_init(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Chain *chain)
1617 {
1618         FLAC__ASSERT(0 != iterator);
1619         FLAC__ASSERT(0 != chain);
1620         FLAC__ASSERT(0 != chain->head);
1621
1622         iterator->chain = chain;
1623         iterator->current = chain->head;
1624 }
1625
1626 FLAC_API FLAC__bool FLAC__metadata_iterator_next(FLAC__Metadata_Iterator *iterator)
1627 {
1628         FLAC__ASSERT(0 != iterator);
1629
1630         if(0 == iterator->current || 0 == iterator->current->next)
1631                 return false;
1632
1633         iterator->current = iterator->current->next;
1634         return true;
1635 }
1636
1637 FLAC_API FLAC__bool FLAC__metadata_iterator_prev(FLAC__Metadata_Iterator *iterator)
1638 {
1639         FLAC__ASSERT(0 != iterator);
1640
1641         if(0 == iterator->current || 0 == iterator->current->prev)
1642                 return false;
1643
1644         iterator->current = iterator->current->prev;
1645         return true;
1646 }
1647
1648 FLAC_API FLAC__MetadataType FLAC__metadata_iterator_get_block_type(const FLAC__Metadata_Iterator *iterator)
1649 {
1650         FLAC__ASSERT(0 != iterator);
1651         FLAC__ASSERT(0 != iterator->current);
1652         FLAC__ASSERT(0 != iterator->current->data);
1653
1654         return iterator->current->data->type;
1655 }
1656
1657 FLAC_API FLAC__StreamMetadata *FLAC__metadata_iterator_get_block(FLAC__Metadata_Iterator *iterator)
1658 {
1659         FLAC__ASSERT(0 != iterator);
1660         FLAC__ASSERT(0 != iterator->current);
1661
1662         return iterator->current->data;
1663 }
1664
1665 FLAC_API FLAC__bool FLAC__metadata_iterator_set_block(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1666 {
1667         FLAC__ASSERT(0 != iterator);
1668         FLAC__ASSERT(0 != block);
1669         return FLAC__metadata_iterator_delete_block(iterator, false) && FLAC__metadata_iterator_insert_block_after(iterator, block);
1670 }
1671
1672 FLAC_API FLAC__bool FLAC__metadata_iterator_delete_block(FLAC__Metadata_Iterator *iterator, FLAC__bool replace_with_padding)
1673 {
1674         FLAC__Metadata_Node *save;
1675
1676         FLAC__ASSERT(0 != iterator);
1677         FLAC__ASSERT(0 != iterator->current);
1678
1679         if(0 == iterator->current->prev) {
1680                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1681                 return false;
1682         }
1683
1684         save = iterator->current->prev;
1685
1686         if(replace_with_padding) {
1687                 FLAC__metadata_object_delete_data(iterator->current->data);
1688                 iterator->current->data->type = FLAC__METADATA_TYPE_PADDING;
1689         }
1690         else {
1691                 chain_delete_node_(iterator->chain, iterator->current);
1692         }
1693
1694         iterator->current = save;
1695         return true;
1696 }
1697
1698 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_before(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1699 {
1700         FLAC__Metadata_Node *node;
1701
1702         FLAC__ASSERT(0 != iterator);
1703         FLAC__ASSERT(0 != iterator->current);
1704         FLAC__ASSERT(0 != block);
1705
1706         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1707                 return false;
1708
1709         if(0 == iterator->current->prev) {
1710                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1711                 return false;
1712         }
1713
1714         if(0 == (node = node_new_()))
1715                 return false;
1716
1717         node->data = block;
1718         iterator_insert_node_(iterator, node);
1719         iterator->current = node;
1720         return true;
1721 }
1722
1723 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_after(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1724 {
1725         FLAC__Metadata_Node *node;
1726
1727         FLAC__ASSERT(0 != iterator);
1728         FLAC__ASSERT(0 != iterator->current);
1729         FLAC__ASSERT(0 != block);
1730
1731         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1732                 return false;
1733
1734         if(0 == (node = node_new_()))
1735                 return false;
1736
1737         node->data = block;
1738         iterator_insert_node_after_(iterator, node);
1739         iterator->current = node;
1740         return true;
1741 }
1742
1743
1744 /****************************************************************************
1745  *
1746  * Local function definitions
1747  *
1748  ***************************************************************************/
1749
1750 void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
1751 {
1752         unsigned i;
1753
1754         b += bytes;
1755
1756         for(i = 0; i < bytes; i++) {
1757                 *(--b) = (FLAC__byte)(val & 0xff);
1758                 val >>= 8;
1759         }
1760 }
1761
1762 void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
1763 {
1764         unsigned i;
1765
1766         for(i = 0; i < bytes; i++) {
1767                 *(b++) = (FLAC__byte)(val & 0xff);
1768                 val >>= 8;
1769         }
1770 }
1771
1772 void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes)
1773 {
1774         unsigned i;
1775
1776         b += bytes;
1777
1778         for(i = 0; i < bytes; i++) {
1779                 *(--b) = (FLAC__byte)(val & 0xff);
1780                 val >>= 8;
1781         }
1782 }
1783
1784 FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes)
1785 {
1786         FLAC__uint32 ret = 0;
1787         unsigned i;
1788
1789         for(i = 0; i < bytes; i++)
1790                 ret = (ret << 8) | (FLAC__uint32)(*b++);
1791
1792         return ret;
1793 }
1794
1795 FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes)
1796 {
1797         FLAC__uint32 ret = 0;
1798         unsigned i;
1799
1800         b += bytes;
1801
1802         for(i = 0; i < bytes; i++)
1803                 ret = (ret << 8) | (FLAC__uint32)(*--b);
1804
1805         return ret;
1806 }
1807
1808 FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes)
1809 {
1810         FLAC__uint64 ret = 0;
1811         unsigned i;
1812
1813         for(i = 0; i < bytes; i++)
1814                 ret = (ret << 8) | (FLAC__uint64)(*b++);
1815
1816         return ret;
1817 }
1818
1819 FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator)
1820 {
1821         FLAC__ASSERT(0 != iterator);
1822         FLAC__ASSERT(0 != iterator->file);
1823
1824         if(!read_metadata_block_header_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, &iterator->is_last, &iterator->type, &iterator->length)) {
1825                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1826                 return false;
1827         }
1828
1829         return true;
1830 }
1831
1832 FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block)
1833 {
1834         FLAC__ASSERT(0 != iterator);
1835         FLAC__ASSERT(0 != iterator->file);
1836
1837         iterator->status = read_metadata_block_data_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, block);
1838
1839         return (iterator->status == FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK);
1840 }
1841
1842 FLAC__bool read_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__bool *is_last, FLAC__MetadataType *type, unsigned *length)
1843 {
1844         FLAC__byte raw_header[FLAC__STREAM_METADATA_HEADER_LENGTH];
1845
1846         if(read_cb(raw_header, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
1847                 return false;
1848
1849         *is_last = raw_header[0] & 0x80? true : false;
1850         *type = (FLAC__MetadataType)(raw_header[0] & 0x7f);
1851         *length = unpack_uint32_(raw_header + 1, 3);
1852
1853         /* Note that we don't check:
1854          *    if(iterator->type >= FLAC__METADATA_TYPE_UNDEFINED)
1855          * we just will read in an opaque block
1856          */
1857
1858         return true;
1859 }
1860
1861 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata *block)
1862 {
1863         switch(block->type) {
1864                 case FLAC__METADATA_TYPE_STREAMINFO:
1865                         return read_metadata_block_data_streaminfo_cb_(handle, read_cb, &block->data.stream_info);
1866                 case FLAC__METADATA_TYPE_PADDING:
1867                         return read_metadata_block_data_padding_cb_(handle, seek_cb, &block->data.padding, block->length);
1868                 case FLAC__METADATA_TYPE_APPLICATION:
1869                         return read_metadata_block_data_application_cb_(handle, read_cb, &block->data.application, block->length);
1870                 case FLAC__METADATA_TYPE_SEEKTABLE:
1871                         return read_metadata_block_data_seektable_cb_(handle, read_cb, &block->data.seek_table, block->length);
1872                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
1873                         return read_metadata_block_data_vorbis_comment_cb_(handle, read_cb, &block->data.vorbis_comment);
1874                 case FLAC__METADATA_TYPE_CUESHEET:
1875                         return read_metadata_block_data_cuesheet_cb_(handle, read_cb, &block->data.cue_sheet);
1876                 default:
1877                         return read_metadata_block_data_unknown_cb_(handle, read_cb, &block->data.unknown, block->length);
1878         }
1879 }
1880
1881 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_StreamInfo *block)
1882 {
1883         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH], *b;
1884
1885         if(read_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
1886                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1887
1888         b = buffer;
1889
1890         /* we are using hardcoded numbers for simplicity but we should
1891          * probably eventually write a bit-level unpacker and use the
1892          * _STREAMINFO_ constants.
1893          */
1894         block->min_blocksize = unpack_uint32_(b, 2); b += 2;
1895         block->max_blocksize = unpack_uint32_(b, 2); b += 2;
1896         block->min_framesize = unpack_uint32_(b, 3); b += 3;
1897         block->max_framesize = unpack_uint32_(b, 3); b += 3;
1898         block->sample_rate = (unpack_uint32_(b, 2) << 4) | ((unsigned)(b[2] & 0xf0) >> 4);
1899         block->channels = (unsigned)((b[2] & 0x0e) >> 1) + 1;
1900         block->bits_per_sample = ((((unsigned)(b[2] & 0x01)) << 4) | (((unsigned)(b[3] & 0xf0)) >> 4)) + 1;
1901         block->total_samples = (((FLAC__uint64)(b[3] & 0x0f)) << 32) | unpack_uint64_(b+4, 4);
1902         memcpy(block->md5sum, b+8, 16);
1903
1904         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1905 }
1906
1907
1908 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata_Padding *block, unsigned block_length)
1909 {
1910         (void)block; /* nothing to do; we don't care about reading the padding bytes */
1911
1912         if(0 != seek_cb(handle, block_length, SEEK_CUR))
1913                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
1914
1915         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1916 }
1917
1918 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Application *block, unsigned block_length)
1919 {
1920         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
1921
1922         if(read_cb(block->id, 1, id_bytes, handle) != id_bytes)
1923                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1924
1925         block_length -= id_bytes;
1926
1927         if(block_length == 0) {
1928                 block->data = 0;
1929         }
1930         else {
1931                 if(0 == (block->data = (FLAC__byte*)malloc(block_length)))
1932                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
1933
1934                 if(read_cb(block->data, 1, block_length, handle) != block_length)
1935                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1936         }
1937
1938         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1939 }
1940
1941 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_SeekTable *block, unsigned block_length)
1942 {
1943         unsigned i;
1944         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
1945
1946         FLAC__ASSERT(block_length % FLAC__STREAM_METADATA_SEEKPOINT_LENGTH == 0);
1947
1948         block->num_points = block_length / FLAC__STREAM_METADATA_SEEKPOINT_LENGTH;
1949
1950         if(block->num_points == 0)
1951                 block->points = 0;
1952         else if(0 == (block->points = (FLAC__StreamMetadata_SeekPoint*)malloc(block->num_points * sizeof(FLAC__StreamMetadata_SeekPoint))))
1953                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
1954
1955         for(i = 0; i < block->num_points; i++) {
1956                 if(read_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
1957                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1958                 /* some MAGIC NUMBERs here */
1959                 block->points[i].sample_number = unpack_uint64_(buffer, 8);
1960                 block->points[i].stream_offset = unpack_uint64_(buffer+8, 8);
1961                 block->points[i].frame_samples = unpack_uint32_(buffer+16, 2);
1962         }
1963
1964         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1965 }
1966
1967 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_entry_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment_Entry *entry)
1968 {
1969         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
1970         FLAC__byte buffer[4]; /* magic number is asserted below */
1971
1972         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8 == 4);
1973
1974         if(read_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
1975                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1976         entry->length = unpack_uint32_little_endian_(buffer, entry_length_len);
1977
1978         if(0 != entry->entry)
1979                 free(entry->entry);
1980
1981         if(entry->length == 0) {
1982                 entry->entry = 0;
1983         }
1984         else {
1985                 if(0 == (entry->entry = (FLAC__byte*)malloc(entry->length)))
1986                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
1987
1988                 if(read_cb(entry->entry, 1, entry->length, handle) != entry->length)
1989                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
1990         }
1991
1992         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1993 }
1994
1995 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment *block)
1996 {
1997         unsigned i;
1998         FLAC__Metadata_SimpleIteratorStatus status;
1999         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2000         FLAC__byte buffer[4]; /* magic number is asserted below */
2001
2002         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8 == 4);
2003
2004         if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, &(block->vendor_string))))
2005                 return status;
2006
2007         if(read_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2008                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2009         block->num_comments = unpack_uint32_little_endian_(buffer, num_comments_len);
2010
2011         if(block->num_comments == 0) {
2012                 block->comments = 0;
2013         }
2014         else if(0 == (block->comments = (FLAC__StreamMetadata_VorbisComment_Entry*)calloc(block->num_comments, sizeof(FLAC__StreamMetadata_VorbisComment_Entry))))
2015                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2016
2017         for(i = 0; i < block->num_comments; i++) {
2018                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, block->comments + i)))
2019                         return status;
2020         }
2021
2022         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2023 }
2024
2025 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet_Track *track)
2026 {
2027         unsigned i, len;
2028         FLAC__byte buffer[32]; /* asserted below that this is big enough */
2029
2030         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2031         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2032         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);
2033
2034         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2035         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2036         if(read_cb(buffer, 1, len, handle) != len)
2037                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2038         track->offset = unpack_uint64_(buffer, len);
2039
2040         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2041         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2042         if(read_cb(buffer, 1, len, handle) != len)
2043                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2044         track->number = (FLAC__byte)unpack_uint32_(buffer, len);
2045
2046         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2047         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2048         if(read_cb(track->isrc, 1, len, handle) != len)
2049                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2050
2051         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);
2052         len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2053         if(read_cb(buffer, 1, len, handle) != len)
2054                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2055         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN == 1);
2056         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN == 1);
2057         track->type = buffer[0] >> 7;
2058         track->pre_emphasis = (buffer[0] >> 6) & 1;
2059
2060         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2061         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2062         if(read_cb(buffer, 1, len, handle) != len)
2063                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2064         track->num_indices = (FLAC__byte)unpack_uint32_(buffer, len);
2065
2066         if(track->num_indices == 0) {
2067                 track->indices = 0;
2068         }
2069         else if(0 == (track->indices = (FLAC__StreamMetadata_CueSheet_Index*)calloc(track->num_indices, sizeof(FLAC__StreamMetadata_CueSheet_Index))))
2070                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2071
2072         for(i = 0; i < track->num_indices; i++) {
2073                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2074                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2075                 if(read_cb(buffer, 1, len, handle) != len)
2076                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2077                 track->indices[i].offset = unpack_uint64_(buffer, len);
2078
2079                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2080                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2081                 if(read_cb(buffer, 1, len, handle) != len)
2082                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2083                 track->indices[i].number = (FLAC__byte)unpack_uint32_(buffer, len);
2084
2085                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2086                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2087                 if(read_cb(buffer, 1, len, handle) != len)
2088                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2089         }
2090
2091         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2092 }
2093
2094 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet *block)
2095 {
2096         unsigned i, len;
2097         FLAC__Metadata_SimpleIteratorStatus status;
2098         FLAC__byte buffer[1024]; /* MSVC needs a constant expression so we put a magic number and assert */
2099
2100         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN)/8 <= sizeof(buffer));
2101         FLAC__ASSERT(sizeof(FLAC__uint64) <= sizeof(buffer));
2102
2103         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2104         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2105         if(read_cb(block->media_catalog_number, 1, len, handle) != len)
2106                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2107
2108         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2109         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2110         if(read_cb(buffer, 1, len, handle) != len)
2111                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2112         block->lead_in = unpack_uint64_(buffer, len);
2113
2114         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2115         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2116         if(read_cb(buffer, 1, len, handle) != len)
2117                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2118         block->is_cd = buffer[0]&0x80? true : false;
2119
2120         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2121         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2122         if(read_cb(buffer, 1, len, handle) != len)
2123                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2124         block->num_tracks = unpack_uint32_(buffer, len);
2125
2126         if(block->num_tracks == 0) {
2127                 block->tracks = 0;
2128         }
2129         else if(0 == (block->tracks = (FLAC__StreamMetadata_CueSheet_Track*)calloc(block->num_tracks, sizeof(FLAC__StreamMetadata_CueSheet_Track))))
2130                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2131
2132         for(i = 0; i < block->num_tracks; i++) {
2133                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_cuesheet_track_cb_(handle, read_cb, block->tracks + i)))
2134                         return status;
2135         }
2136
2137         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2138 }
2139
2140 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2141 {
2142         if(block_length == 0) {
2143                 block->data = 0;
2144         }
2145         else {
2146                 if(0 == (block->data = (FLAC__byte*)malloc(block_length)))
2147                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2148
2149                 if(read_cb(block->data, 1, block_length, handle) != block_length)
2150                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2151         }
2152
2153         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2154 }
2155
2156 FLAC__bool write_metadata_block_header_(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_header_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2162                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2163                 return false;
2164         }
2165
2166         return true;
2167 }
2168
2169 FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2170 {
2171         FLAC__ASSERT(0 != file);
2172         FLAC__ASSERT(0 != status);
2173
2174         if (write_metadata_block_data_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2175                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2176                 return true;
2177         }
2178         else {
2179                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2180                 return false;
2181         }
2182 }
2183
2184 FLAC__bool write_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2185 {
2186         FLAC__byte buffer[FLAC__STREAM_METADATA_HEADER_LENGTH];
2187
2188         FLAC__ASSERT(block->length < (1u << FLAC__STREAM_METADATA_LENGTH_LEN));
2189
2190         buffer[0] = (block->is_last? 0x80 : 0) | (FLAC__byte)block->type;
2191         pack_uint32_(block->length, buffer + 1, 3);
2192
2193         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
2194                 return false;
2195
2196         return true;
2197 }
2198
2199 FLAC__bool write_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2200 {
2201         FLAC__ASSERT(0 != block);
2202
2203         switch(block->type) {
2204                 case FLAC__METADATA_TYPE_STREAMINFO:
2205                         return write_metadata_block_data_streaminfo_cb_(handle, write_cb, &block->data.stream_info);
2206                 case FLAC__METADATA_TYPE_PADDING:
2207                         return write_metadata_block_data_padding_cb_(handle, write_cb, &block->data.padding, block->length);
2208                 case FLAC__METADATA_TYPE_APPLICATION:
2209                         return write_metadata_block_data_application_cb_(handle, write_cb, &block->data.application, block->length);
2210                 case FLAC__METADATA_TYPE_SEEKTABLE:
2211                         return write_metadata_block_data_seektable_cb_(handle, write_cb, &block->data.seek_table);
2212                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
2213                         return write_metadata_block_data_vorbis_comment_cb_(handle, write_cb, &block->data.vorbis_comment);
2214                 case FLAC__METADATA_TYPE_CUESHEET:
2215                         return write_metadata_block_data_cuesheet_cb_(handle, write_cb, &block->data.cue_sheet);
2216                 default:
2217                         return write_metadata_block_data_unknown_cb_(handle, write_cb, &block->data.unknown, block->length);
2218         }
2219 }
2220
2221 FLAC__bool write_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_StreamInfo *block)
2222 {
2223         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH];
2224         const unsigned channels1 = block->channels - 1;
2225         const unsigned bps1 = block->bits_per_sample - 1;
2226
2227         /* we are using hardcoded numbers for simplicity but we should
2228          * probably eventually write a bit-level packer and use the
2229          * _STREAMINFO_ constants.
2230          */
2231         pack_uint32_(block->min_blocksize, buffer, 2);
2232         pack_uint32_(block->max_blocksize, buffer+2, 2);
2233         pack_uint32_(block->min_framesize, buffer+4, 3);
2234         pack_uint32_(block->max_framesize, buffer+7, 3);
2235         buffer[10] = (block->sample_rate >> 12) & 0xff;
2236         buffer[11] = (block->sample_rate >> 4) & 0xff;
2237         buffer[12] = ((block->sample_rate & 0x0f) << 4) | (channels1 << 1) | (bps1 >> 4);
2238         buffer[13] = (FLAC__byte)(((bps1 & 0x0f) << 4) | ((block->total_samples >> 32) & 0x0f));
2239         pack_uint32_((FLAC__uint32)block->total_samples, buffer+14, 4);
2240         memcpy(buffer+18, block->md5sum, 16);
2241
2242         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
2243                 return false;
2244
2245         return true;
2246 }
2247
2248 FLAC__bool write_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Padding *block, unsigned block_length)
2249 {
2250         unsigned i, n = block_length;
2251         FLAC__byte buffer[1024];
2252
2253         (void)block;
2254
2255         memset(buffer, 0, 1024);
2256
2257         for(i = 0; i < n/1024; i++)
2258                 if(write_cb(buffer, 1, 1024, handle) != 1024)
2259                         return false;
2260
2261         n %= 1024;
2262
2263         if(write_cb(buffer, 1, n, handle) != n)
2264                 return false;
2265
2266         return true;
2267 }
2268
2269 FLAC__bool write_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Application *block, unsigned block_length)
2270 {
2271         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
2272
2273         if(write_cb(block->id, 1, id_bytes, handle) != id_bytes)
2274                 return false;
2275
2276         block_length -= id_bytes;
2277
2278         if(write_cb(block->data, 1, block_length, handle) != block_length)
2279                 return false;
2280
2281         return true;
2282 }
2283
2284 FLAC__bool write_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_SeekTable *block)
2285 {
2286         unsigned i;
2287         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
2288
2289         for(i = 0; i < block->num_points; i++) {
2290                 /* some MAGIC NUMBERs here */
2291                 pack_uint64_(block->points[i].sample_number, buffer, 8);
2292                 pack_uint64_(block->points[i].stream_offset, buffer+8, 8);
2293                 pack_uint32_(block->points[i].frame_samples, buffer+16, 2);
2294                 if(write_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
2295                         return false;
2296         }
2297
2298         return true;
2299 }
2300
2301 FLAC__bool write_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_VorbisComment *block)
2302 {
2303         unsigned i;
2304         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
2305         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2306         FLAC__byte buffer[4]; /* magic number is asserted below */
2307
2308         FLAC__ASSERT(max(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN, FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN) / 8 == 4);
2309
2310         pack_uint32_little_endian_(block->vendor_string.length, buffer, entry_length_len);
2311         if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2312                 return false;
2313         if(write_cb(block->vendor_string.entry, 1, block->vendor_string.length, handle) != block->vendor_string.length)
2314                 return false;
2315
2316         pack_uint32_little_endian_(block->num_comments, buffer, num_comments_len);
2317         if(write_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2318                 return false;
2319
2320         for(i = 0; i < block->num_comments; i++) {
2321                 pack_uint32_little_endian_(block->comments[i].length, buffer, entry_length_len);
2322                 if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2323                         return false;
2324                 if(write_cb(block->comments[i].entry, 1, block->comments[i].length, handle) != block->comments[i].length)
2325                         return false;
2326         }
2327
2328         return true;
2329 }
2330
2331 FLAC__bool write_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_CueSheet *block)
2332 {
2333         unsigned i, j, len;
2334         FLAC__byte buffer[1024]; /* asserted below that this is big enough */
2335
2336         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2337         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN/8);
2338         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);
2339         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2340
2341         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2342         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2343         if(write_cb(block->media_catalog_number, 1, len, handle) != len)
2344                 return false;
2345
2346         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2347         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2348         pack_uint64_(block->lead_in, buffer, len);
2349         if(write_cb(buffer, 1, len, handle) != len)
2350                 return false;
2351
2352         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2353         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2354         memset(buffer, 0, len);
2355         if(block->is_cd)
2356                 buffer[0] |= 0x80;
2357         if(write_cb(buffer, 1, len, handle) != len)
2358                 return false;
2359
2360         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2361         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2362         pack_uint32_(block->num_tracks, buffer, len);
2363         if(write_cb(buffer, 1, len, handle) != len)
2364                 return false;
2365
2366         for(i = 0; i < block->num_tracks; i++) {
2367                 FLAC__StreamMetadata_CueSheet_Track *track = block->tracks + i;
2368
2369                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2370                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2371                 pack_uint64_(track->offset, buffer, len);
2372                 if(write_cb(buffer, 1, len, handle) != len)
2373                         return false;
2374
2375                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2376                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2377                 pack_uint32_(track->number, buffer, len);
2378                 if(write_cb(buffer, 1, len, handle) != len)
2379                         return false;
2380
2381                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2382                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2383                 if(write_cb(track->isrc, 1, len, handle) != len)
2384                         return false;
2385
2386                 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);
2387                 len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2388                 memset(buffer, 0, len);
2389                 buffer[0] = (track->type << 7) | (track->pre_emphasis << 6);
2390                 if(write_cb(buffer, 1, len, handle) != len)
2391                         return false;
2392
2393                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2394                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2395                 pack_uint32_(track->num_indices, buffer, len);
2396                 if(write_cb(buffer, 1, len, handle) != len)
2397                         return false;
2398
2399                 for(j = 0; j < track->num_indices; j++) {
2400                         FLAC__StreamMetadata_CueSheet_Index *index = track->indices + j;
2401
2402                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2403                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2404                         pack_uint64_(index->offset, buffer, len);
2405                         if(write_cb(buffer, 1, len, handle) != len)
2406                                 return false;
2407
2408                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2409                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2410                         pack_uint32_(index->number, buffer, len);
2411                         if(write_cb(buffer, 1, len, handle) != len)
2412                                 return false;
2413
2414                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2415                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2416                         memset(buffer, 0, len);
2417                         if(write_cb(buffer, 1, len, handle) != len)
2418                                 return false;
2419                 }
2420         }
2421
2422         return true;
2423 }
2424
2425 FLAC__bool write_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2426 {
2427         if(write_cb(block->data, 1, block_length, handle) != block_length)
2428                 return false;
2429
2430         return true;
2431 }
2432
2433 FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block)
2434 {
2435         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2436                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2437                 return false;
2438         }
2439
2440         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2441                 return false;
2442
2443         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2444                 return false;
2445
2446         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2447                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2448                 return false;
2449         }
2450
2451         return read_metadata_block_header_(iterator);
2452 }
2453
2454 FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last)
2455 {
2456         FLAC__StreamMetadata *padding;
2457
2458         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2459                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2460                 return false;
2461         }
2462
2463         block->is_last = false;
2464
2465         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2466                 return false;
2467
2468         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2469                 return false;
2470
2471         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING)))
2472                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2473
2474         padding->is_last = padding_is_last;
2475         padding->length = padding_length;
2476
2477         if(!write_metadata_block_header_(iterator->file, &iterator->status, padding)) {
2478                 FLAC__metadata_object_delete(padding);
2479                 return false;
2480         }
2481
2482         if(!write_metadata_block_data_(iterator->file, &iterator->status, padding)) {
2483                 FLAC__metadata_object_delete(padding);
2484                 return false;
2485         }
2486
2487         FLAC__metadata_object_delete(padding);
2488
2489         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2490                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2491                 return false;
2492         }
2493
2494         return read_metadata_block_header_(iterator);
2495 }
2496
2497 FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append)
2498 {
2499         FILE *tempfile;
2500         char *tempfilename;
2501         int fixup_is_last_code = 0; /* 0 => no need to change any is_last flags */
2502         long fixup_is_last_flag_offset = -1;
2503
2504         FLAC__ASSERT(0 != block || append == false);
2505
2506         if(iterator->is_last) {
2507                 if(append) {
2508                         fixup_is_last_code = 1; /* 1 => clear the is_last flag at the following offset */
2509                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2510                 }
2511                 else if(0 == block) {
2512                         simple_iterator_push_(iterator);
2513                         if(!FLAC__metadata_simple_iterator_prev(iterator)) {
2514                                 (void)simple_iterator_pop_(iterator);
2515                                 return false;
2516                         }
2517                         fixup_is_last_code = -1; /* -1 => set the is_last the flag at the following offset */
2518                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2519                         if(!simple_iterator_pop_(iterator))
2520                                 return false;
2521                 }
2522         }
2523
2524         if(!simple_iterator_copy_file_prefix_(iterator, &tempfile, &tempfilename, append))
2525                 return false;
2526
2527         if(0 != block) {
2528                 if(!write_metadata_block_header_(tempfile, &iterator->status, block)) {
2529                         cleanup_tempfile_(&tempfile, &tempfilename);
2530                         return false;
2531                 }
2532
2533                 if(!write_metadata_block_data_(tempfile, &iterator->status, block)) {
2534                         cleanup_tempfile_(&tempfile, &tempfilename);
2535                         return false;
2536                 }
2537         }
2538
2539         if(!simple_iterator_copy_file_postfix_(iterator, &tempfile, &tempfilename, fixup_is_last_code, fixup_is_last_flag_offset, block==0))
2540                 return false;
2541
2542         if(append)
2543                 return FLAC__metadata_simple_iterator_next(iterator);
2544
2545         return true;
2546 }
2547
2548 void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator)
2549 {
2550         FLAC__ASSERT(iterator->depth+1 < SIMPLE_ITERATOR_MAX_PUSH_DEPTH);
2551         iterator->offset[iterator->depth+1] = iterator->offset[iterator->depth];
2552         iterator->depth++;
2553 }
2554
2555 FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator)
2556 {
2557         FLAC__ASSERT(iterator->depth > 0);
2558         iterator->depth--;
2559         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2560                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2561                 return false;
2562         }
2563
2564         return read_metadata_block_header_(iterator);
2565 }
2566
2567 /* return meanings:
2568  * 0: ok
2569  * 1: read error
2570  * 2: seek error
2571  * 3: not a FLAC file
2572  */
2573 unsigned seek_to_first_metadata_block_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb)
2574 {
2575         FLAC__byte buffer[4];
2576         size_t n;
2577         unsigned i;
2578
2579         FLAC__ASSERT(FLAC__STREAM_SYNC_LENGTH == 4);
2580
2581         /* skip any id3v2 tag */
2582         errno = 0;
2583         n = read_cb(buffer, 1, 4, handle);
2584         if(errno)
2585                 return 1;
2586         else if(n != 4)
2587                 return 3;
2588         else if(0 == memcmp(buffer, "ID3", 3)) {
2589                 unsigned tag_length = 0;
2590
2591                 /* skip to the tag length */
2592                 if(seek_cb(handle, 2, SEEK_CUR) < 0)
2593                         return 2;
2594
2595                 /* read the length */
2596                 for(i = 0; i < 4; i++) {
2597                         if(read_cb(buffer, 1, 1, handle) < 1 || buffer[0] & 0x80)
2598                                 return 1;
2599                         tag_length <<= 7;
2600                         tag_length |= (buffer[0] & 0x7f);
2601                 }
2602
2603                 /* skip the rest of the tag */
2604                 if(seek_cb(handle, tag_length, SEEK_CUR) < 0)
2605                         return 2;
2606
2607                 /* read the stream sync code */
2608                 errno = 0;
2609                 n = read_cb(buffer, 1, 4, handle);
2610                 if(errno)
2611                         return 1;
2612                 else if(n != 4)
2613                         return 3;
2614         }
2615
2616         /* check for the fLaC signature */
2617         if(0 == memcmp(FLAC__STREAM_SYNC_STRING, buffer, FLAC__STREAM_SYNC_LENGTH))
2618                 return 0;
2619         else
2620                 return 3;
2621 }
2622
2623 unsigned seek_to_first_metadata_block_(FILE *f)
2624 {
2625         return seek_to_first_metadata_block_cb_((FLAC__IOHandle)f, (FLAC__IOCallback_Read)fread, fseek_wrapper_);
2626 }
2627
2628 FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append)
2629 {
2630         const long offset_end = append? iterator->offset[iterator->depth] + (long)FLAC__STREAM_METADATA_HEADER_LENGTH + (long)iterator->length : iterator->offset[iterator->depth];
2631
2632         if(0 != fseek(iterator->file, 0, SEEK_SET)) {
2633                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2634                 return false;
2635         }
2636         if(!open_tempfile_(iterator->filename, iterator->tempfile_path_prefix, tempfile, tempfilename, &iterator->status)) {
2637                 cleanup_tempfile_(tempfile, tempfilename);
2638                 return false;
2639         }
2640         if(!copy_n_bytes_from_file_(iterator->file, *tempfile, offset_end, &iterator->status)) {
2641                 cleanup_tempfile_(tempfile, tempfilename);
2642                 return false;
2643         }
2644
2645         return true;
2646 }
2647
2648 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)
2649 {
2650         long save_offset = iterator->offset[iterator->depth]; /*@@@ 2G limit */
2651         FLAC__ASSERT(0 != *tempfile);
2652
2653         if(0 != fseek(iterator->file, save_offset + FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length, SEEK_SET)) {
2654                 cleanup_tempfile_(tempfile, tempfilename);
2655                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2656                 return false;
2657         }
2658         if(!copy_remaining_bytes_from_file_(iterator->file, *tempfile, &iterator->status)) {
2659                 cleanup_tempfile_(tempfile, tempfilename);
2660                 return false;
2661         }
2662
2663         if(fixup_is_last_code != 0) {
2664                 /*
2665                  * if code == 1, it means a block was appended to the end so
2666                  *   we have to clear the is_last flag of the previous block
2667                  * if code == -1, it means the last block was deleted so
2668                  *   we have to set the is_last flag of the previous block
2669                  */
2670                 /* MAGIC NUMBERs here; we know the is_last flag is the high bit of the byte at this location */
2671                 FLAC__byte x;
2672                 if(0 != fseek(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
2673                         cleanup_tempfile_(tempfile, tempfilename);
2674                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2675                         return false;
2676                 }
2677                 if(fread(&x, 1, 1, *tempfile) != 1) {
2678                         cleanup_tempfile_(tempfile, tempfilename);
2679                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2680                         return false;
2681                 }
2682                 if(fixup_is_last_code > 0) {
2683                         FLAC__ASSERT(x & 0x80);
2684                         x &= 0x7f;
2685                 }
2686                 else {
2687                         FLAC__ASSERT(!(x & 0x80));
2688                         x |= 0x80;
2689                 }
2690                 if(0 != fseek(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
2691                         cleanup_tempfile_(tempfile, tempfilename);
2692                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2693                         return false;
2694                 }
2695                 if(local__fwrite(&x, 1, 1, *tempfile) != 1) {
2696                         cleanup_tempfile_(tempfile, tempfilename);
2697                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2698                         return false;
2699                 }
2700         }
2701
2702         (void)fclose(iterator->file);
2703
2704         if(!transport_tempfile_(iterator->filename, tempfile, tempfilename, &iterator->status))
2705                 return false;
2706
2707         if(iterator->has_stats)
2708                 set_file_stats_(iterator->filename, &iterator->stats);
2709
2710         if(!simple_iterator_prime_input_(iterator, !iterator->is_writable))
2711                 return false;
2712         if(backup) {
2713                 while(iterator->offset[iterator->depth] + (long)FLAC__STREAM_METADATA_HEADER_LENGTH + (long)iterator->length < save_offset)
2714                         if(!FLAC__metadata_simple_iterator_next(iterator))
2715                                 return false;
2716                 return true;
2717         }
2718         else {
2719                 /* move the iterator to it's original block faster by faking a push, then doing a pop_ */
2720                 FLAC__ASSERT(iterator->depth == 0);
2721                 iterator->offset[0] = save_offset;
2722                 iterator->depth++;
2723                 return simple_iterator_pop_(iterator);
2724         }
2725 }
2726
2727 FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, unsigned bytes/*@@@ 4G limit*/, FLAC__Metadata_SimpleIteratorStatus *status)
2728 {
2729         FLAC__byte buffer[8192];
2730         unsigned n;
2731
2732         while(bytes > 0) {
2733                 n = min(sizeof(buffer), bytes);
2734                 if(fread(buffer, 1, n, file) != n) {
2735                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2736                         return false;
2737                 }
2738                 if(local__fwrite(buffer, 1, n, tempfile) != n) {
2739                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2740                         return false;
2741                 }
2742                 bytes -= n;
2743         }
2744
2745         return true;
2746 }
2747
2748 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)
2749 {
2750         FLAC__byte buffer[8192];
2751         unsigned n;
2752
2753         while(bytes > 0) {
2754                 n = min(sizeof(buffer), bytes);
2755                 if(read_cb(buffer, 1, n, handle) != n) {
2756                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2757                         return false;
2758                 }
2759                 if(temp_write_cb(buffer, 1, n, temp_handle) != n) {
2760                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2761                         return false;
2762                 }
2763                 bytes -= n;
2764         }
2765
2766         return true;
2767 }
2768
2769 FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status)
2770 {
2771         FLAC__byte buffer[8192];
2772         size_t n;
2773
2774         while(!feof(file)) {
2775                 n = fread(buffer, 1, sizeof(buffer), file);
2776                 if(n == 0 && !feof(file)) {
2777                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2778                         return false;
2779                 }
2780                 if(n > 0 && local__fwrite(buffer, 1, n, tempfile) != n) {
2781                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2782                         return false;
2783                 }
2784         }
2785
2786         return true;
2787 }
2788
2789 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)
2790 {
2791         FLAC__byte buffer[8192];
2792         size_t n;
2793
2794         while(!eof_cb(handle)) {
2795                 n = read_cb(buffer, 1, sizeof(buffer), handle);
2796                 if(n == 0 && !eof_cb(handle)) {
2797                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2798                         return false;
2799                 }
2800                 if(n > 0 && temp_write_cb(buffer, 1, n, temp_handle) != n) {
2801                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2802                         return false;
2803                 }
2804         }
2805
2806         return true;
2807 }
2808
2809 FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
2810 {
2811         static const char *tempfile_suffix = ".metadata_edit";
2812         if(0 == tempfile_path_prefix) {
2813                 if(0 == (*tempfilename = (char*)malloc(strlen(filename) + strlen(tempfile_suffix) + 1))) {
2814                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2815                         return false;
2816                 }
2817                 strcpy(*tempfilename, filename);
2818                 strcat(*tempfilename, tempfile_suffix);
2819         }
2820         else {
2821                 const char *p = strrchr(filename, '/');
2822                 if(0 == p)
2823                         p = filename;
2824                 else
2825                         p++;
2826
2827                 if(0 == (*tempfilename = (char*)malloc(strlen(tempfile_path_prefix) + 1 + strlen(p) + strlen(tempfile_suffix) + 1))) {
2828                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2829                         return false;
2830                 }
2831                 strcpy(*tempfilename, tempfile_path_prefix);
2832                 strcat(*tempfilename, "/");
2833                 strcat(*tempfilename, p);
2834                 strcat(*tempfilename, tempfile_suffix);
2835         }
2836
2837         if(0 == (*tempfile = fopen(*tempfilename, "w+b"))) {
2838                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
2839                 return false;
2840         }
2841
2842         return true;
2843 }
2844
2845 FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
2846 {
2847         FLAC__ASSERT(0 != filename);
2848         FLAC__ASSERT(0 != tempfile);
2849         FLAC__ASSERT(0 != *tempfile);
2850         FLAC__ASSERT(0 != tempfilename);
2851         FLAC__ASSERT(0 != *tempfilename);
2852         FLAC__ASSERT(0 != status);
2853
2854         (void)fclose(*tempfile);
2855         *tempfile = 0;
2856
2857 #if defined _MSC_VER || defined __MINGW32__
2858         if(unlink(filename) < 0) {
2859                 cleanup_tempfile_(tempfile, tempfilename);
2860                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR;
2861                 return false;
2862         }
2863 #endif
2864
2865         /*@@@ to fully support the tempfile_path_prefix we need to update this piece to actually copy across filesystems instead of just rename(): */
2866         if(0 != rename(*tempfilename, filename)) {
2867                 cleanup_tempfile_(tempfile, tempfilename);
2868                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR;
2869                 return false;
2870         }
2871
2872         cleanup_tempfile_(tempfile, tempfilename);
2873
2874         return true;
2875 }
2876
2877 void cleanup_tempfile_(FILE **tempfile, char **tempfilename)
2878 {
2879         if(0 != *tempfile) {
2880                 (void)fclose(*tempfile);
2881                 *tempfile = 0;
2882         }
2883
2884         if(0 != *tempfilename) {
2885                 (void)unlink(*tempfilename);
2886                 free(*tempfilename);
2887                 *tempfilename = 0;
2888         }
2889 }
2890
2891 FLAC__bool get_file_stats_(const char *filename, struct stat *stats)
2892 {
2893         FLAC__ASSERT(0 != filename);
2894         FLAC__ASSERT(0 != stats);
2895         return (0 == stat(filename, stats));
2896 }
2897
2898 void set_file_stats_(const char *filename, struct stat *stats)
2899 {
2900         struct utimbuf srctime;
2901
2902         FLAC__ASSERT(0 != filename);
2903         FLAC__ASSERT(0 != stats);
2904
2905         srctime.actime = stats->st_atime;
2906         srctime.modtime = stats->st_mtime;
2907         (void)chmod(filename, stats->st_mode);
2908         (void)utime(filename, &srctime);
2909 #if !defined _MSC_VER && !defined __MINGW32__
2910         (void)chown(filename, stats->st_uid, -1);
2911         (void)chown(filename, -1, stats->st_gid);
2912 #endif
2913 }
2914
2915 /* @@@ WATCHOUT @@@
2916  * We cast FLAC__int64 to long and use fseek()/ftell() because
2917  * none of our operations on metadata is ever likely to go past
2918  * 2 gigabytes.
2919  */
2920 int fseek_wrapper_(FLAC__IOHandle handle, FLAC__int64 offset, int whence)
2921 {
2922         FLAC__ASSERT(offset <= 0x7fffffff);
2923         return fseek((FILE*)handle, (long)offset, whence);
2924 }
2925
2926 FLAC__int64 ftell_wrapper_(FLAC__IOHandle handle)
2927 {
2928         return (long)ftell((FILE*)handle);
2929 }
2930
2931 FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status)
2932 {
2933         switch(status) {
2934                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK:
2935                         return FLAC__METADATA_CHAIN_STATUS_OK;
2936                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT:
2937                         return FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT;
2938                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE:
2939                         return FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
2940                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE:
2941                         return FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE;
2942                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE:
2943                         return FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE;
2944                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA:
2945                         return FLAC__METADATA_CHAIN_STATUS_BAD_METADATA;
2946                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR:
2947                         return FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
2948                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR:
2949                         return FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
2950                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR:
2951                         return FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
2952                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR:
2953                         return FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR;
2954                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR:
2955                         return FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR;
2956                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR:
2957                         return FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
2958                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR:
2959                 default:
2960                         return FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
2961         }
2962 }