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