src/libFLAC/metadata_iterators.c

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