src/libFLAC/metadata_iterators.c

   1 /* libFLAC - Free Lossless Audio Codec library
   2  * Copyright (C) 2001,2002,2003,2004,2005  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+1)))
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                 entry->entry[entry->length] = '\0';
1992         }
1993
1994         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
1995 }
1996
1997 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment *block)
1998 {
1999         unsigned i;
2000         FLAC__Metadata_SimpleIteratorStatus status;
2001         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2002         FLAC__byte buffer[4]; /* magic number is asserted below */
2003
2004         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8 == 4);
2005
2006         if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, &(block->vendor_string))))
2007                 return status;
2008
2009         if(read_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2010                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2011         block->num_comments = unpack_uint32_little_endian_(buffer, num_comments_len);
2012
2013         if(block->num_comments == 0) {
2014                 block->comments = 0;
2015         }
2016         else if(0 == (block->comments = (FLAC__StreamMetadata_VorbisComment_Entry*)calloc(block->num_comments, sizeof(FLAC__StreamMetadata_VorbisComment_Entry))))
2017                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2018
2019         for(i = 0; i < block->num_comments; i++) {
2020                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, block->comments + i)))
2021                         return status;
2022         }
2023
2024         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2025 }
2026
2027 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet_Track *track)
2028 {
2029         unsigned i, len;
2030         FLAC__byte buffer[32]; /* asserted below that this is big enough */
2031
2032         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2033         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2034         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);
2035
2036         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2037         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2038         if(read_cb(buffer, 1, len, handle) != len)
2039                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2040         track->offset = unpack_uint64_(buffer, len);
2041
2042         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2043         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2044         if(read_cb(buffer, 1, len, handle) != len)
2045                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2046         track->number = (FLAC__byte)unpack_uint32_(buffer, len);
2047
2048         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2049         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2050         if(read_cb(track->isrc, 1, len, handle) != len)
2051                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2052
2053         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);
2054         len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2055         if(read_cb(buffer, 1, len, handle) != len)
2056                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2057         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN == 1);
2058         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN == 1);
2059         track->type = buffer[0] >> 7;
2060         track->pre_emphasis = (buffer[0] >> 6) & 1;
2061
2062         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2063         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2064         if(read_cb(buffer, 1, len, handle) != len)
2065                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2066         track->num_indices = (FLAC__byte)unpack_uint32_(buffer, len);
2067
2068         if(track->num_indices == 0) {
2069                 track->indices = 0;
2070         }
2071         else if(0 == (track->indices = (FLAC__StreamMetadata_CueSheet_Index*)calloc(track->num_indices, sizeof(FLAC__StreamMetadata_CueSheet_Index))))
2072                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2073
2074         for(i = 0; i < track->num_indices; i++) {
2075                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2076                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2077                 if(read_cb(buffer, 1, len, handle) != len)
2078                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2079                 track->indices[i].offset = unpack_uint64_(buffer, len);
2080
2081                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2082                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2083                 if(read_cb(buffer, 1, len, handle) != len)
2084                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2085                 track->indices[i].number = (FLAC__byte)unpack_uint32_(buffer, len);
2086
2087                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2088                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2089                 if(read_cb(buffer, 1, len, handle) != len)
2090                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2091         }
2092
2093         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2094 }
2095
2096 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet *block)
2097 {
2098         unsigned i, len;
2099         FLAC__Metadata_SimpleIteratorStatus status;
2100         FLAC__byte buffer[1024]; /* MSVC needs a constant expression so we put a magic number and assert */
2101
2102         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN)/8 <= sizeof(buffer));
2103         FLAC__ASSERT(sizeof(FLAC__uint64) <= sizeof(buffer));
2104
2105         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2106         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2107         if(read_cb(block->media_catalog_number, 1, len, handle) != len)
2108                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2109
2110         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2111         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2112         if(read_cb(buffer, 1, len, handle) != len)
2113                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2114         block->lead_in = unpack_uint64_(buffer, len);
2115
2116         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2117         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2118         if(read_cb(buffer, 1, len, handle) != len)
2119                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2120         block->is_cd = buffer[0]&0x80? true : false;
2121
2122         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2123         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2124         if(read_cb(buffer, 1, len, handle) != len)
2125                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2126         block->num_tracks = unpack_uint32_(buffer, len);
2127
2128         if(block->num_tracks == 0) {
2129                 block->tracks = 0;
2130         }
2131         else if(0 == (block->tracks = (FLAC__StreamMetadata_CueSheet_Track*)calloc(block->num_tracks, sizeof(FLAC__StreamMetadata_CueSheet_Track))))
2132                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2133
2134         for(i = 0; i < block->num_tracks; i++) {
2135                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_cuesheet_track_cb_(handle, read_cb, block->tracks + i)))
2136                         return status;
2137         }
2138
2139         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2140 }
2141
2142 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2143 {
2144         if(block_length == 0) {
2145                 block->data = 0;
2146         }
2147         else {
2148                 if(0 == (block->data = (FLAC__byte*)malloc(block_length)))
2149                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2150
2151                 if(read_cb(block->data, 1, block_length, handle) != block_length)
2152                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2153         }
2154
2155         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2156 }
2157
2158 FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2159 {
2160         FLAC__ASSERT(0 != file);
2161         FLAC__ASSERT(0 != status);
2162
2163         if(!write_metadata_block_header_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2164                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2165                 return false;
2166         }
2167
2168         return true;
2169 }
2170
2171 FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2172 {
2173         FLAC__ASSERT(0 != file);
2174         FLAC__ASSERT(0 != status);
2175
2176         if (write_metadata_block_data_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2177                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2178                 return true;
2179         }
2180         else {
2181                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2182                 return false;
2183         }
2184 }
2185
2186 FLAC__bool write_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2187 {
2188         FLAC__byte buffer[FLAC__STREAM_METADATA_HEADER_LENGTH];
2189
2190         FLAC__ASSERT(block->length < (1u << FLAC__STREAM_METADATA_LENGTH_LEN));
2191
2192         buffer[0] = (block->is_last? 0x80 : 0) | (FLAC__byte)block->type;
2193         pack_uint32_(block->length, buffer + 1, 3);
2194
2195         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
2196                 return false;
2197
2198         return true;
2199 }
2200
2201 FLAC__bool write_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2202 {
2203         FLAC__ASSERT(0 != block);
2204
2205         switch(block->type) {
2206                 case FLAC__METADATA_TYPE_STREAMINFO:
2207                         return write_metadata_block_data_streaminfo_cb_(handle, write_cb, &block->data.stream_info);
2208                 case FLAC__METADATA_TYPE_PADDING:
2209                         return write_metadata_block_data_padding_cb_(handle, write_cb, &block->data.padding, block->length);
2210                 case FLAC__METADATA_TYPE_APPLICATION:
2211                         return write_metadata_block_data_application_cb_(handle, write_cb, &block->data.application, block->length);
2212                 case FLAC__METADATA_TYPE_SEEKTABLE:
2213                         return write_metadata_block_data_seektable_cb_(handle, write_cb, &block->data.seek_table);
2214                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
2215                         return write_metadata_block_data_vorbis_comment_cb_(handle, write_cb, &block->data.vorbis_comment);
2216                 case FLAC__METADATA_TYPE_CUESHEET:
2217                         return write_metadata_block_data_cuesheet_cb_(handle, write_cb, &block->data.cue_sheet);
2218                 default:
2219                         return write_metadata_block_data_unknown_cb_(handle, write_cb, &block->data.unknown, block->length);
2220         }
2221 }
2222
2223 FLAC__bool write_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_StreamInfo *block)
2224 {
2225         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH];
2226         const unsigned channels1 = block->channels - 1;
2227         const unsigned bps1 = block->bits_per_sample - 1;
2228
2229         /* we are using hardcoded numbers for simplicity but we should
2230          * probably eventually write a bit-level packer and use the
2231          * _STREAMINFO_ constants.
2232          */
2233         pack_uint32_(block->min_blocksize, buffer, 2);
2234         pack_uint32_(block->max_blocksize, buffer+2, 2);
2235         pack_uint32_(block->min_framesize, buffer+4, 3);
2236         pack_uint32_(block->max_framesize, buffer+7, 3);
2237         buffer[10] = (block->sample_rate >> 12) & 0xff;
2238         buffer[11] = (block->sample_rate >> 4) & 0xff;
2239         buffer[12] = ((block->sample_rate & 0x0f) << 4) | (channels1 << 1) | (bps1 >> 4);
2240         buffer[13] = (FLAC__byte)(((bps1 & 0x0f) << 4) | ((block->total_samples >> 32) & 0x0f));
2241         pack_uint32_((FLAC__uint32)block->total_samples, buffer+14, 4);
2242         memcpy(buffer+18, block->md5sum, 16);
2243
2244         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
2245                 return false;
2246
2247         return true;
2248 }
2249
2250 FLAC__bool write_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Padding *block, unsigned block_length)
2251 {
2252         unsigned i, n = block_length;
2253         FLAC__byte buffer[1024];
2254
2255         (void)block;
2256
2257         memset(buffer, 0, 1024);
2258
2259         for(i = 0; i < n/1024; i++)
2260                 if(write_cb(buffer, 1, 1024, handle) != 1024)
2261                         return false;
2262
2263         n %= 1024;
2264
2265         if(write_cb(buffer, 1, n, handle) != n)
2266                 return false;
2267
2268         return true;
2269 }
2270
2271 FLAC__bool write_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Application *block, unsigned block_length)
2272 {
2273         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
2274
2275         if(write_cb(block->id, 1, id_bytes, handle) != id_bytes)
2276                 return false;
2277
2278         block_length -= id_bytes;
2279
2280         if(write_cb(block->data, 1, block_length, handle) != block_length)
2281                 return false;
2282
2283         return true;
2284 }
2285
2286 FLAC__bool write_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_SeekTable *block)
2287 {
2288         unsigned i;
2289         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
2290
2291         for(i = 0; i < block->num_points; i++) {
2292                 /* some MAGIC NUMBERs here */
2293                 pack_uint64_(block->points[i].sample_number, buffer, 8);
2294                 pack_uint64_(block->points[i].stream_offset, buffer+8, 8);
2295                 pack_uint32_(block->points[i].frame_samples, buffer+16, 2);
2296                 if(write_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
2297                         return false;
2298         }
2299
2300         return true;
2301 }
2302
2303 FLAC__bool write_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_VorbisComment *block)
2304 {
2305         unsigned i;
2306         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
2307         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2308         FLAC__byte buffer[4]; /* magic number is asserted below */
2309
2310         FLAC__ASSERT(max(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN, FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN) / 8 == 4);
2311
2312         pack_uint32_little_endian_(block->vendor_string.length, buffer, entry_length_len);
2313         if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2314                 return false;
2315         if(write_cb(block->vendor_string.entry, 1, block->vendor_string.length, handle) != block->vendor_string.length)
2316                 return false;
2317
2318         pack_uint32_little_endian_(block->num_comments, buffer, num_comments_len);
2319         if(write_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2320                 return false;
2321
2322         for(i = 0; i < block->num_comments; i++) {
2323                 pack_uint32_little_endian_(block->comments[i].length, buffer, entry_length_len);
2324                 if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2325                         return false;
2326                 if(write_cb(block->comments[i].entry, 1, block->comments[i].length, handle) != block->comments[i].length)
2327                         return false;
2328         }
2329
2330         return true;
2331 }
2332
2333 FLAC__bool write_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_CueSheet *block)
2334 {
2335         unsigned i, j, len;
2336         FLAC__byte buffer[1024]; /* asserted below that this is big enough */
2337
2338         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2339         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN/8);
2340         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);
2341         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2342
2343         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2344         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2345         if(write_cb(block->media_catalog_number, 1, len, handle) != len)
2346                 return false;
2347
2348         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2349         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2350         pack_uint64_(block->lead_in, buffer, len);
2351         if(write_cb(buffer, 1, len, handle) != len)
2352                 return false;
2353
2354         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2355         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2356         memset(buffer, 0, len);
2357         if(block->is_cd)
2358                 buffer[0] |= 0x80;
2359         if(write_cb(buffer, 1, len, handle) != len)
2360                 return false;
2361
2362         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2363         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2364         pack_uint32_(block->num_tracks, buffer, len);
2365         if(write_cb(buffer, 1, len, handle) != len)
2366                 return false;
2367
2368         for(i = 0; i < block->num_tracks; i++) {
2369                 FLAC__StreamMetadata_CueSheet_Track *track = block->tracks + i;
2370
2371                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2372                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2373                 pack_uint64_(track->offset, buffer, len);
2374                 if(write_cb(buffer, 1, len, handle) != len)
2375                         return false;
2376
2377                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2378                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2379                 pack_uint32_(track->number, buffer, len);
2380                 if(write_cb(buffer, 1, len, handle) != len)
2381                         return false;
2382
2383                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2384                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2385                 if(write_cb(track->isrc, 1, len, handle) != len)
2386                         return false;
2387
2388                 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);
2389                 len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2390                 memset(buffer, 0, len);
2391                 buffer[0] = (track->type << 7) | (track->pre_emphasis << 6);
2392                 if(write_cb(buffer, 1, len, handle) != len)
2393                         return false;
2394
2395                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2396                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2397                 pack_uint32_(track->num_indices, buffer, len);
2398                 if(write_cb(buffer, 1, len, handle) != len)
2399                         return false;
2400
2401                 for(j = 0; j < track->num_indices; j++) {
2402                         FLAC__StreamMetadata_CueSheet_Index *index = track->indices + j;
2403
2404                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2405                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2406                         pack_uint64_(index->offset, buffer, len);
2407                         if(write_cb(buffer, 1, len, handle) != len)
2408                                 return false;
2409
2410                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2411                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2412                         pack_uint32_(index->number, buffer, len);
2413                         if(write_cb(buffer, 1, len, handle) != len)
2414                                 return false;
2415
2416                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2417                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2418                         memset(buffer, 0, len);
2419                         if(write_cb(buffer, 1, len, handle) != len)
2420                                 return false;
2421                 }
2422         }
2423
2424         return true;
2425 }
2426
2427 FLAC__bool write_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2428 {
2429         if(write_cb(block->data, 1, block_length, handle) != block_length)
2430                 return false;
2431
2432         return true;
2433 }
2434
2435 FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block)
2436 {
2437         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2438                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2439                 return false;
2440         }
2441
2442         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2443                 return false;
2444
2445         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2446                 return false;
2447
2448         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2449                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2450                 return false;
2451         }
2452
2453         return read_metadata_block_header_(iterator);
2454 }
2455
2456 FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last)
2457 {
2458         FLAC__StreamMetadata *padding;
2459
2460         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2461                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2462                 return false;
2463         }
2464
2465         block->is_last = false;
2466
2467         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2468                 return false;
2469
2470         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2471                 return false;
2472
2473         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING)))
2474                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2475
2476         padding->is_last = padding_is_last;
2477         padding->length = padding_length;
2478
2479         if(!write_metadata_block_header_(iterator->file, &iterator->status, padding)) {
2480                 FLAC__metadata_object_delete(padding);
2481                 return false;
2482         }
2483
2484         if(!write_metadata_block_data_(iterator->file, &iterator->status, padding)) {
2485                 FLAC__metadata_object_delete(padding);
2486                 return false;
2487         }
2488
2489         FLAC__metadata_object_delete(padding);
2490
2491         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2492                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2493                 return false;
2494         }
2495
2496         return read_metadata_block_header_(iterator);
2497 }
2498
2499 FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append)
2500 {
2501         FILE *tempfile;
2502         char *tempfilename;
2503         int fixup_is_last_code = 0; /* 0 => no need to change any is_last flags */
2504         long fixup_is_last_flag_offset = -1;
2505
2506         FLAC__ASSERT(0 != block || append == false);
2507
2508         if(iterator->is_last) {
2509                 if(append) {
2510                         fixup_is_last_code = 1; /* 1 => clear the is_last flag at the following offset */
2511                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2512                 }
2513                 else if(0 == block) {
2514                         simple_iterator_push_(iterator);
2515                         if(!FLAC__metadata_simple_iterator_prev(iterator)) {
2516                                 (void)simple_iterator_pop_(iterator);
2517                                 return false;
2518                         }
2519                         fixup_is_last_code = -1; /* -1 => set the is_last the flag at the following offset */
2520                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2521                         if(!simple_iterator_pop_(iterator))
2522                                 return false;
2523                 }
2524         }
2525
2526         if(!simple_iterator_copy_file_prefix_(iterator, &tempfile, &tempfilename, append))
2527                 return false;
2528
2529         if(0 != block) {
2530                 if(!write_metadata_block_header_(tempfile, &iterator->status, block)) {
2531                         cleanup_tempfile_(&tempfile, &tempfilename);
2532                         return false;
2533                 }
2534
2535                 if(!write_metadata_block_data_(tempfile, &iterator->status, block)) {
2536                         cleanup_tempfile_(&tempfile, &tempfilename);
2537                         return false;
2538                 }
2539         }
2540
2541         if(!simple_iterator_copy_file_postfix_(iterator, &tempfile, &tempfilename, fixup_is_last_code, fixup_is_last_flag_offset, block==0))
2542                 return false;
2543
2544         if(append)
2545                 return FLAC__metadata_simple_iterator_next(iterator);
2546
2547         return true;
2548 }
2549
2550 void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator)
2551 {
2552         FLAC__ASSERT(iterator->depth+1 < SIMPLE_ITERATOR_MAX_PUSH_DEPTH);
2553         iterator->offset[iterator->depth+1] = iterator->offset[iterator->depth];
2554         iterator->depth++;
2555 }
2556
2557 FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator)
2558 {
2559         FLAC__ASSERT(iterator->depth > 0);
2560         iterator->depth--;
2561         if(0 != fseek(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2562                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2563                 return false;
2564         }
2565
2566         return read_metadata_block_header_(iterator);
2567 }
2568
2569 /* return meanings:
2570  * 0: ok
2571  * 1: read error
2572  * 2: seek error
2573  * 3: not a FLAC file
2574  */
2575 unsigned seek_to_first_metadata_block_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb)
2576 {
2577         FLAC__byte buffer[4];
2578         size_t n;
2579         unsigned i;
2580
2581         FLAC__ASSERT(FLAC__STREAM_SYNC_LENGTH == 4);
2582
2583         /* skip any id3v2 tag */
2584         errno = 0;
2585         n = read_cb(buffer, 1, 4, handle);
2586         if(errno)
2587                 return 1;
2588         else if(n != 4)
2589                 return 3;
2590         else if(0 == memcmp(buffer, "ID3", 3)) {
2591                 unsigned tag_length = 0;
2592
2593                 /* skip to the tag length */
2594                 if(seek_cb(handle, 2, SEEK_CUR) < 0)
2595                         return 2;
2596
2597                 /* read the length */
2598                 for(i = 0; i < 4; i++) {
2599                         if(read_cb(buffer, 1, 1, handle) < 1 || buffer[0] & 0x80)
2600                                 return 1;
2601                         tag_length <<= 7;
2602                         tag_length |= (buffer[0] & 0x7f);
2603                 }
2604
2605                 /* skip the rest of the tag */
2606                 if(seek_cb(handle, tag_length, SEEK_CUR) < 0)
2607                         return 2;
2608
2609                 /* read the stream sync code */
2610                 errno = 0;
2611                 n = read_cb(buffer, 1, 4, handle);
2612                 if(errno)
2613                         return 1;
2614                 else if(n != 4)
2615                         return 3;
2616         }
2617
2618         /* check for the fLaC signature */
2619         if(0 == memcmp(FLAC__STREAM_SYNC_STRING, buffer, FLAC__STREAM_SYNC_LENGTH))
2620                 return 0;
2621         else
2622                 return 3;
2623 }
2624
2625 unsigned seek_to_first_metadata_block_(FILE *f)
2626 {
2627         return seek_to_first_metadata_block_cb_((FLAC__IOHandle)f, (FLAC__IOCallback_Read)fread, fseek_wrapper_);
2628 }
2629
2630 FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append)
2631 {
2632         const long offset_end = append? iterator->offset[iterator->depth] + (long)FLAC__STREAM_METADATA_HEADER_LENGTH + (long)iterator->length : iterator->offset[iterator->depth];
2633
2634         if(0 != fseek(iterator->file, 0, SEEK_SET)) {
2635                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2636                 return false;
2637         }
2638         if(!open_tempfile_(iterator->filename, iterator->tempfile_path_prefix, tempfile, tempfilename, &iterator->status)) {
2639                 cleanup_tempfile_(tempfile, tempfilename);
2640                 return false;
2641         }
2642         if(!copy_n_bytes_from_file_(iterator->file, *tempfile, offset_end, &iterator->status)) {
2643                 cleanup_tempfile_(tempfile, tempfilename);
2644                 return false;
2645         }
2646
2647         return true;
2648 }
2649
2650 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)
2651 {
2652         long save_offset = iterator->offset[iterator->depth]; /*@@@ 2G limit */
2653         FLAC__ASSERT(0 != *tempfile);
2654
2655         if(0 != fseek(iterator->file, save_offset + FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length, SEEK_SET)) {
2656                 cleanup_tempfile_(tempfile, tempfilename);
2657                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2658                 return false;
2659         }
2660         if(!copy_remaining_bytes_from_file_(iterator->file, *tempfile, &iterator->status)) {
2661                 cleanup_tempfile_(tempfile, tempfilename);
2662                 return false;
2663         }
2664
2665         if(fixup_is_last_code != 0) {
2666                 /*
2667                  * if code == 1, it means a block was appended to the end so
2668                  *   we have to clear the is_last flag of the previous block
2669                  * if code == -1, it means the last block was deleted so
2670                  *   we have to set the is_last flag of the previous block
2671                  */
2672                 /* MAGIC NUMBERs here; we know the is_last flag is the high bit of the byte at this location */
2673                 FLAC__byte x;
2674                 if(0 != fseek(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
2675                         cleanup_tempfile_(tempfile, tempfilename);
2676                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2677                         return false;
2678                 }
2679                 if(fread(&x, 1, 1, *tempfile) != 1) {
2680                         cleanup_tempfile_(tempfile, tempfilename);
2681                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2682                         return false;
2683                 }
2684                 if(fixup_is_last_code > 0) {
2685                         FLAC__ASSERT(x & 0x80);
2686                         x &= 0x7f;
2687                 }
2688                 else {
2689                         FLAC__ASSERT(!(x & 0x80));
2690                         x |= 0x80;
2691                 }
2692                 if(0 != fseek(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
2693                         cleanup_tempfile_(tempfile, tempfilename);
2694                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2695                         return false;
2696                 }
2697                 if(local__fwrite(&x, 1, 1, *tempfile) != 1) {
2698                         cleanup_tempfile_(tempfile, tempfilename);
2699                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2700                         return false;
2701                 }
2702         }
2703
2704         (void)fclose(iterator->file);
2705
2706         if(!transport_tempfile_(iterator->filename, tempfile, tempfilename, &iterator->status))
2707                 return false;
2708
2709         if(iterator->has_stats)
2710                 set_file_stats_(iterator->filename, &iterator->stats);
2711
2712         if(!simple_iterator_prime_input_(iterator, !iterator->is_writable))
2713                 return false;
2714         if(backup) {
2715                 while(iterator->offset[iterator->depth] + (long)FLAC__STREAM_METADATA_HEADER_LENGTH + (long)iterator->length < save_offset)
2716                         if(!FLAC__metadata_simple_iterator_next(iterator))
2717                                 return false;
2718                 return true;
2719         }
2720         else {
2721                 /* move the iterator to it's original block faster by faking a push, then doing a pop_ */
2722                 FLAC__ASSERT(iterator->depth == 0);
2723                 iterator->offset[0] = save_offset;
2724                 iterator->depth++;
2725                 return simple_iterator_pop_(iterator);
2726         }
2727 }
2728
2729 FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, unsigned bytes/*@@@ 4G limit*/, FLAC__Metadata_SimpleIteratorStatus *status)
2730 {
2731         FLAC__byte buffer[8192];
2732         unsigned n;
2733
2734         while(bytes > 0) {
2735                 n = min(sizeof(buffer), bytes);
2736                 if(fread(buffer, 1, n, file) != n) {
2737                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2738                         return false;
2739                 }
2740                 if(local__fwrite(buffer, 1, n, tempfile) != n) {
2741                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2742                         return false;
2743                 }
2744                 bytes -= n;
2745         }
2746
2747         return true;
2748 }
2749
2750 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)
2751 {
2752         FLAC__byte buffer[8192];
2753         unsigned n;
2754
2755         while(bytes > 0) {
2756                 n = min(sizeof(buffer), bytes);
2757                 if(read_cb(buffer, 1, n, handle) != n) {
2758                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2759                         return false;
2760                 }
2761                 if(temp_write_cb(buffer, 1, n, temp_handle) != n) {
2762                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2763                         return false;
2764                 }
2765                 bytes -= n;
2766         }
2767
2768         return true;
2769 }
2770
2771 FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status)
2772 {
2773         FLAC__byte buffer[8192];
2774         size_t n;
2775
2776         while(!feof(file)) {
2777                 n = fread(buffer, 1, sizeof(buffer), file);
2778                 if(n == 0 && !feof(file)) {
2779                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2780                         return false;
2781                 }
2782                 if(n > 0 && local__fwrite(buffer, 1, n, tempfile) != n) {
2783                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2784                         return false;
2785                 }
2786         }
2787
2788         return true;
2789 }
2790
2791 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)
2792 {
2793         FLAC__byte buffer[8192];
2794         size_t n;
2795
2796         while(!eof_cb(handle)) {
2797                 n = read_cb(buffer, 1, sizeof(buffer), handle);
2798                 if(n == 0 && !eof_cb(handle)) {
2799                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2800                         return false;
2801                 }
2802                 if(n > 0 && temp_write_cb(buffer, 1, n, temp_handle) != n) {
2803                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2804                         return false;
2805                 }
2806         }
2807
2808         return true;
2809 }
2810
2811 FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
2812 {
2813         static const char *tempfile_suffix = ".metadata_edit";
2814         if(0 == tempfile_path_prefix) {
2815                 if(0 == (*tempfilename = (char*)malloc(strlen(filename) + strlen(tempfile_suffix) + 1))) {
2816                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2817                         return false;
2818                 }
2819                 strcpy(*tempfilename, filename);
2820                 strcat(*tempfilename, tempfile_suffix);
2821         }
2822         else {
2823                 const char *p = strrchr(filename, '/');
2824                 if(0 == p)
2825                         p = filename;
2826                 else
2827                         p++;
2828
2829                 if(0 == (*tempfilename = (char*)malloc(strlen(tempfile_path_prefix) + 1 + strlen(p) + strlen(tempfile_suffix) + 1))) {
2830                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2831                         return false;
2832                 }
2833                 strcpy(*tempfilename, tempfile_path_prefix);
2834                 strcat(*tempfilename, "/");
2835                 strcat(*tempfilename, p);
2836                 strcat(*tempfilename, tempfile_suffix);
2837         }
2838
2839         if(0 == (*tempfile = fopen(*tempfilename, "w+b"))) {
2840                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
2841                 return false;
2842         }
2843
2844         return true;
2845 }
2846
2847 FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
2848 {
2849         FLAC__ASSERT(0 != filename);
2850         FLAC__ASSERT(0 != tempfile);
2851         FLAC__ASSERT(0 != *tempfile);
2852         FLAC__ASSERT(0 != tempfilename);
2853         FLAC__ASSERT(0 != *tempfilename);
2854         FLAC__ASSERT(0 != status);
2855
2856         (void)fclose(*tempfile);
2857         *tempfile = 0;
2858
2859 #if defined _MSC_VER || defined __MINGW32__ || defined __EMX__
2860         if(unlink(filename) < 0) {
2861                 cleanup_tempfile_(tempfile, tempfilename);
2862                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR;
2863                 return false;
2864         }
2865 #endif
2866
2867         /*@@@ to fully support the tempfile_path_prefix we need to update this piece to actually copy across filesystems instead of just rename(): */
2868         if(0 != rename(*tempfilename, filename)) {
2869                 cleanup_tempfile_(tempfile, tempfilename);
2870                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR;
2871                 return false;
2872         }
2873
2874         cleanup_tempfile_(tempfile, tempfilename);
2875
2876         return true;
2877 }
2878
2879 void cleanup_tempfile_(FILE **tempfile, char **tempfilename)
2880 {
2881         if(0 != *tempfile) {
2882                 (void)fclose(*tempfile);
2883                 *tempfile = 0;
2884         }
2885
2886         if(0 != *tempfilename) {
2887                 (void)unlink(*tempfilename);
2888                 free(*tempfilename);
2889                 *tempfilename = 0;
2890         }
2891 }
2892
2893 FLAC__bool get_file_stats_(const char *filename, struct stat *stats)
2894 {
2895         FLAC__ASSERT(0 != filename);
2896         FLAC__ASSERT(0 != stats);
2897         return (0 == stat(filename, stats));
2898 }
2899
2900 void set_file_stats_(const char *filename, struct stat *stats)
2901 {
2902         struct utimbuf srctime;
2903
2904         FLAC__ASSERT(0 != filename);
2905         FLAC__ASSERT(0 != stats);
2906
2907         srctime.actime = stats->st_atime;
2908         srctime.modtime = stats->st_mtime;
2909         (void)chmod(filename, stats->st_mode);
2910         (void)utime(filename, &srctime);
2911 #if !defined _MSC_VER && !defined __MINGW32__ && !defined __EMX__
2912         (void)chown(filename, stats->st_uid, -1);
2913         (void)chown(filename, -1, stats->st_gid);
2914 #endif
2915 }
2916
2917 /* @@@ WATCHOUT @@@
2918  * We cast FLAC__int64 to long and use fseek()/ftell() because
2919  * none of our operations on metadata is ever likely to go past
2920  * 2 gigabytes.
2921  */
2922 int fseek_wrapper_(FLAC__IOHandle handle, FLAC__int64 offset, int whence)
2923 {
2924         FLAC__ASSERT(offset <= 0x7fffffff);
2925         return fseek((FILE*)handle, (long)offset, whence);
2926 }
2927
2928 FLAC__int64 ftell_wrapper_(FLAC__IOHandle handle)
2929 {
2930         return (long)ftell((FILE*)handle);
2931 }
2932
2933 FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status)
2934 {
2935         switch(status) {
2936                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK:
2937                         return FLAC__METADATA_CHAIN_STATUS_OK;
2938                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT:
2939                         return FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT;
2940                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE:
2941                         return FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
2942                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE:
2943                         return FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE;
2944                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE:
2945                         return FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE;
2946                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA:
2947                         return FLAC__METADATA_CHAIN_STATUS_BAD_METADATA;
2948                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR:
2949                         return FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
2950                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR:
2951                         return FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
2952                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR:
2953                         return FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
2954                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR:
2955                         return FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR;
2956                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR:
2957                         return FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR;
2958                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR:
2959                         return FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
2960                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR:
2961                 default:
2962                         return FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
2963         }
2964 }