src/libFLAC/metadata_iterators.c

   1 /* libFLAC - Free Lossless Audio Codec library
   2  * Copyright (C) 2001,2002,2003,2004,2005,2006,2007,2008,2009  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 #if HAVE_CONFIG_H
  33 #  include <config.h>
  34 #endif
  35
  36 #include <errno.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40
  41 #include <sys/stat.h> /* for stat(), maybe chmod() */
  42
  43 #include "private/metadata.h"
  44
  45 #include "FLAC/assert.h"
  46 #include "FLAC/stream_decoder.h"
  47 #include "share/alloc.h"
  48 #include "share/compat.h"
  49 #include "share/macros.h"
  50 #include "share/safe_str.h"
  51 #include "private/macros.h"
  52 #include "private/memory.h"
  53
  54 /* Alias the first (in share/alloc.h) to the second (in src/libFLAC/memory.c). */
  55 #define safe_malloc_mul_2op_ safe_malloc_mul_2op_p
  56
  57 /****************************************************************************
  58  *
  59  * Local function declarations
  60  *
  61  ***************************************************************************/
  62
  63 static void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes);
  64 static void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes);
  65 static void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes);
  66 static FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes);
  67 static FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes);
  68 static FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes);
  69
  70 static FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator);
  71 static FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block);
  72 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);
  73 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);
  74 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_StreamInfo *block);
  75 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);
  76 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);
  77 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);
  78 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);
  79 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment *block);
  80 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet_Track *track);
  81 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet *block);
  82 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Picture *block);
  83 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);
  84
  85 static FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block);
  86 static FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block);
  87 static FLAC__bool write_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block);
  88 static FLAC__bool write_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block);
  89 static FLAC__bool write_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_StreamInfo *block);
  90 static FLAC__bool write_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Padding *block, unsigned block_length);
  91 static FLAC__bool write_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Application *block, unsigned block_length);
  92 static FLAC__bool write_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_SeekTable *block);
  93 static FLAC__bool write_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_VorbisComment *block);
  94 static FLAC__bool write_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_CueSheet *block);
  95 static FLAC__bool write_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Picture *block);
  96 static FLAC__bool write_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Unknown *block, unsigned block_length);
  97
  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 void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator);
 103 static FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator);
 104
 105 static unsigned seek_to_first_metadata_block_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb);
 106 static unsigned seek_to_first_metadata_block_(FILE *f);
 107
 108 static FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append);
 109 static FLAC__bool simple_iterator_copy_file_postfix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, int fixup_is_last_code, FLAC__off_t fixup_is_last_flag_offset, FLAC__bool backup);
 110
 111 static FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status);
 112 static FLAC__bool copy_n_bytes_from_file_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOHandle temp_handle, FLAC__IOCallback_Write temp_write_cb, FLAC__off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status);
 113 static FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status);
 114 static FLAC__bool copy_remaining_bytes_from_file_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Eof eof_cb, FLAC__IOHandle temp_handle, FLAC__IOCallback_Write temp_write_cb, FLAC__Metadata_SimpleIteratorStatus *status);
 115
 116 static FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status);
 117 static FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status);
 118 static void cleanup_tempfile_(FILE **tempfile, char **tempfilename);
 119
 120 static FLAC__bool get_file_stats_(const char *filename, struct stat *stats);
 121 static void set_file_stats_(const char *filename, struct stat *stats);
 122
 123 static int fseek_wrapper_(FLAC__IOHandle handle, FLAC__int64 offset, int whence);
 124 static FLAC__int64 ftell_wrapper_(FLAC__IOHandle handle);
 125
 126 static FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status);
 127
 128
 129 #ifdef FLAC__VALGRIND_TESTING
 130 static size_t local__fwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream)
 131 {
 132         size_t ret = fwrite(ptr, size, nmemb, stream);
 133         if(!ferror(stream))
 134                 fflush(stream);
 135         return ret;
 136 }
 137 #else
 138 #define local__fwrite fwrite
 139 #endif
 140
 141 /****************************************************************************
 142  *
 143  * Level 0 implementation
 144  *
 145  ***************************************************************************/
 146
 147 static FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data);
 148 static void metadata_callback_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data);
 149 static void error_callback_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data);
 150
 151 typedef struct {
 152         FLAC__bool got_error;
 153         FLAC__StreamMetadata *object;
 154 } level0_client_data;
 155
 156 static FLAC__StreamMetadata *get_one_metadata_block_(const char *filename, FLAC__MetadataType type)
 157 {
 158         level0_client_data cd;
 159         FLAC__StreamDecoder *decoder;
 160
 161         FLAC__ASSERT(0 != filename);
 162
 163         cd.got_error = false;
 164         cd.object = 0;
 165
 166         decoder = FLAC__stream_decoder_new();
 167
 168         if(0 == decoder)
 169                 return 0;
 170
 171         FLAC__stream_decoder_set_md5_checking(decoder, false);
 172         FLAC__stream_decoder_set_metadata_ignore_all(decoder);
 173         FLAC__stream_decoder_set_metadata_respond(decoder, type);
 174
 175         if(FLAC__stream_decoder_init_file(decoder, filename, write_callback_, metadata_callback_, error_callback_, &cd) != FLAC__STREAM_DECODER_INIT_STATUS_OK || cd.got_error) {
 176                 (void)FLAC__stream_decoder_finish(decoder);
 177                 FLAC__stream_decoder_delete(decoder);
 178                 return 0;
 179         }
 180
 181         if(!FLAC__stream_decoder_process_until_end_of_metadata(decoder) || cd.got_error) {
 182                 (void)FLAC__stream_decoder_finish(decoder);
 183                 FLAC__stream_decoder_delete(decoder);
 184                 if(0 != cd.object)
 185                         FLAC__metadata_object_delete(cd.object);
 186                 return 0;
 187         }
 188
 189         (void)FLAC__stream_decoder_finish(decoder);
 190         FLAC__stream_decoder_delete(decoder);
 191
 192         return cd.object;
 193 }
 194
 195 FLAC_API FLAC__bool FLAC__metadata_get_streaminfo(const char *filename, FLAC__StreamMetadata *streaminfo)
 196 {
 197         FLAC__StreamMetadata *object;
 198
 199         FLAC__ASSERT(0 != filename);
 200         FLAC__ASSERT(0 != streaminfo);
 201
 202         object = get_one_metadata_block_(filename, FLAC__METADATA_TYPE_STREAMINFO);
 203
 204         if (object) {
 205                 /* can just copy the contents since STREAMINFO has no internal structure */
 206                 *streaminfo = *object;
 207                 FLAC__metadata_object_delete(object);
 208                 return true;
 209         }
 210         else {
 211                 return false;
 212         }
 213 }
 214
 215 FLAC_API FLAC__bool FLAC__metadata_get_tags(const char *filename, FLAC__StreamMetadata **tags)
 216 {
 217         FLAC__ASSERT(0 != filename);
 218         FLAC__ASSERT(0 != tags);
 219
 220         *tags = get_one_metadata_block_(filename, FLAC__METADATA_TYPE_VORBIS_COMMENT);
 221
 222         return 0 != *tags;
 223 }
 224
 225 FLAC_API FLAC__bool FLAC__metadata_get_cuesheet(const char *filename, FLAC__StreamMetadata **cuesheet)
 226 {
 227         FLAC__ASSERT(0 != filename);
 228         FLAC__ASSERT(0 != cuesheet);
 229
 230         *cuesheet = get_one_metadata_block_(filename, FLAC__METADATA_TYPE_CUESHEET);
 231
 232         return 0 != *cuesheet;
 233 }
 234
 235 FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
 236 {
 237         (void)decoder, (void)frame, (void)buffer, (void)client_data;
 238
 239         return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;
 240 }
 241
 242 void metadata_callback_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
 243 {
 244         level0_client_data *cd = (level0_client_data *)client_data;
 245         (void)decoder;
 246
 247         /*
 248          * we assume we only get here when the one metadata block we were
 249          * looking for was passed to us
 250          */
 251         if(!cd->got_error && 0 == cd->object) {
 252                 if(0 == (cd->object = FLAC__metadata_object_clone(metadata)))
 253                         cd->got_error = true;
 254         }
 255 }
 256
 257 void error_callback_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
 258 {
 259         level0_client_data *cd = (level0_client_data *)client_data;
 260         (void)decoder;
 261
 262         if(status != FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC)
 263                 cd->got_error = true;
 264 }
 265
 266 FLAC_API FLAC__bool FLAC__metadata_get_picture(const char *filename, FLAC__StreamMetadata **picture, FLAC__StreamMetadata_Picture_Type type, const char *mime_type, const FLAC__byte *description, unsigned max_width, unsigned max_height, unsigned max_depth, unsigned max_colors)
 267 {
 268         FLAC__Metadata_SimpleIterator *it;
 269         FLAC__uint64 max_area_seen = 0;
 270         FLAC__uint64 max_depth_seen = 0;
 271
 272         FLAC__ASSERT(0 != filename);
 273         FLAC__ASSERT(0 != picture);
 274
 275         *picture = 0;
 276
 277         it = FLAC__metadata_simple_iterator_new();
 278         if(0 == it)
 279                 return false;
 280         if(!FLAC__metadata_simple_iterator_init(it, filename, /*read_only=*/true, /*preserve_file_stats=*/true)) {
 281                 FLAC__metadata_simple_iterator_delete(it);
 282                 return false;
 283         }
 284         do {
 285                 if(FLAC__metadata_simple_iterator_get_block_type(it) == FLAC__METADATA_TYPE_PICTURE) {
 286                         FLAC__StreamMetadata *obj = FLAC__metadata_simple_iterator_get_block(it);
 287                         FLAC__uint64 area = (FLAC__uint64)obj->data.picture.width * (FLAC__uint64)obj->data.picture.height;
 288                         /* check constraints */
 289                         if(
 290                                 (type == (FLAC__StreamMetadata_Picture_Type)(-1) || type == obj->data.picture.type) &&
 291                                 (mime_type == 0 || !strcmp(mime_type, obj->data.picture.mime_type)) &&
 292                                 (description == 0 || !strcmp((const char *)description, (const char *)obj->data.picture.description)) &&
 293                                 obj->data.picture.width <= max_width &&
 294                                 obj->data.picture.height <= max_height &&
 295                                 obj->data.picture.depth <= max_depth &&
 296                                 obj->data.picture.colors <= max_colors &&
 297                                 (area > max_area_seen || (area == max_area_seen && obj->data.picture.depth > max_depth_seen))
 298                         ) {
 299                                 if(*picture)
 300                                         FLAC__metadata_object_delete(*picture);
 301                                 *picture = obj;
 302                                 max_area_seen = area;
 303                                 max_depth_seen = obj->data.picture.depth;
 304                         }
 305                         else {
 306                                 FLAC__metadata_object_delete(obj);
 307                         }
 308                 }
 309         } while(FLAC__metadata_simple_iterator_next(it));
 310
 311         FLAC__metadata_simple_iterator_delete(it);
 312
 313         return (0 != *picture);
 314 }
 315
 316
 317 /****************************************************************************
 318  *
 319  * Level 1 implementation
 320  *
 321  ***************************************************************************/
 322
 323 #define SIMPLE_ITERATOR_MAX_PUSH_DEPTH (1+4)
 324 /* 1 for initial offset, +4 for our own personal use */
 325
 326 struct FLAC__Metadata_SimpleIterator {
 327         FILE *file;
 328         char *filename, *tempfile_path_prefix;
 329         struct stat stats;
 330         FLAC__bool has_stats;
 331         FLAC__bool is_writable;
 332         FLAC__Metadata_SimpleIteratorStatus status;
 333         FLAC__off_t offset[SIMPLE_ITERATOR_MAX_PUSH_DEPTH];
 334         FLAC__off_t first_offset; /* this is the offset to the STREAMINFO block */
 335         unsigned depth;
 336         /* this is the metadata block header of the current block we are pointing to: */
 337         FLAC__bool is_last;
 338         FLAC__MetadataType type;
 339         unsigned length;
 340 };
 341
 342 FLAC_API const char * const FLAC__Metadata_SimpleIteratorStatusString[] = {
 343         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK",
 344         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT",
 345         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE",
 346         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE",
 347         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE",
 348         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA",
 349         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR",
 350         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR",
 351         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR",
 352         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR",
 353         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR",
 354         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR",
 355         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR"
 356 };
 357
 358
 359 FLAC_API FLAC__Metadata_SimpleIterator *FLAC__metadata_simple_iterator_new(void)
 360 {
 361         FLAC__Metadata_SimpleIterator *iterator = calloc(1, sizeof(FLAC__Metadata_SimpleIterator));
 362
 363         if(0 != iterator) {
 364                 iterator->file = 0;
 365                 iterator->filename = 0;
 366                 iterator->tempfile_path_prefix = 0;
 367                 iterator->has_stats = false;
 368                 iterator->is_writable = false;
 369                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
 370                 iterator->first_offset = iterator->offset[0] = -1;
 371                 iterator->depth = 0;
 372         }
 373
 374         return iterator;
 375 }
 376
 377 static void simple_iterator_free_guts_(FLAC__Metadata_SimpleIterator *iterator)
 378 {
 379         FLAC__ASSERT(0 != iterator);
 380
 381         if(0 != iterator->file) {
 382                 fclose(iterator->file);
 383                 iterator->file = 0;
 384                 if(iterator->has_stats)
 385                         set_file_stats_(iterator->filename, &iterator->stats);
 386         }
 387         if(0 != iterator->filename) {
 388                 free(iterator->filename);
 389                 iterator->filename = 0;
 390         }
 391         if(0 != iterator->tempfile_path_prefix) {
 392                 free(iterator->tempfile_path_prefix);
 393                 iterator->tempfile_path_prefix = 0;
 394         }
 395 }
 396
 397 FLAC_API void FLAC__metadata_simple_iterator_delete(FLAC__Metadata_SimpleIterator *iterator)
 398 {
 399         FLAC__ASSERT(0 != iterator);
 400
 401         simple_iterator_free_guts_(iterator);
 402         free(iterator);
 403 }
 404
 405 FLAC_API FLAC__Metadata_SimpleIteratorStatus FLAC__metadata_simple_iterator_status(FLAC__Metadata_SimpleIterator *iterator)
 406 {
 407         FLAC__Metadata_SimpleIteratorStatus status;
 408
 409         FLAC__ASSERT(0 != iterator);
 410
 411         status = iterator->status;
 412         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
 413         return status;
 414 }
 415
 416 static FLAC__bool simple_iterator_prime_input_(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool read_only)
 417 {
 418         unsigned ret;
 419
 420         FLAC__ASSERT(0 != iterator);
 421
 422         if(read_only || 0 == (iterator->file = fopen(iterator->filename, "r+b"))) {
 423                 iterator->is_writable = false;
 424                 if(read_only || errno == EACCES) {
 425                         if(0 == (iterator->file = fopen(iterator->filename, "rb"))) {
 426                                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
 427                                 return false;
 428                         }
 429                 }
 430                 else {
 431                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
 432                         return false;
 433                 }
 434         }
 435         else {
 436                 iterator->is_writable = true;
 437         }
 438
 439         ret = seek_to_first_metadata_block_(iterator->file);
 440         switch(ret) {
 441                 case 0:
 442                         iterator->depth = 0;
 443                         iterator->first_offset = iterator->offset[iterator->depth] = ftello(iterator->file);
 444                         return read_metadata_block_header_(iterator);
 445                 case 1:
 446                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
 447                         return false;
 448                 case 2:
 449                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 450                         return false;
 451                 case 3:
 452                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE;
 453                         return false;
 454                 default:
 455                         FLAC__ASSERT(0);
 456                         return false;
 457         }
 458 }
 459
 460 #if 0
 461 @@@ If we decide to finish implementing this, put this comment back in metadata.h
 462 /*
 463  * The 'tempfile_path_prefix' allows you to specify a directory where
 464  * tempfiles should go.  Remember that if your metadata edits cause the
 465  * FLAC file to grow, the entire file will have to be rewritten.  If
 466  * 'tempfile_path_prefix' is NULL, the temp file will be written in the
 467  * same directory as the original FLAC file.  This makes replacing the
 468  * original with the tempfile fast but requires extra space in the same
 469  * partition for the tempfile.  If space is a problem, you can pass a
 470  * directory name belonging to a different partition in
 471  * 'tempfile_path_prefix'.  Note that you should use the forward slash
 472  * '/' as the directory separator.  A trailing slash is not needed; it
 473  * will be added automatically.
 474  */
 475 FLAC__bool FLAC__metadata_simple_iterator_init(FLAC__Metadata_SimpleIterator *iterator, const char *filename, FLAC__bool preserve_file_stats, const char *tempfile_path_prefix);
 476 #endif
 477
 478 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)
 479 {
 480         const char *tempfile_path_prefix = 0; /*@@@ search for comments near 'rename(...)' for what it will take to finish implementing this */
 481
 482         FLAC__ASSERT(0 != iterator);
 483         FLAC__ASSERT(0 != filename);
 484
 485         simple_iterator_free_guts_(iterator);
 486
 487         if(!read_only && preserve_file_stats)
 488                 iterator->has_stats = get_file_stats_(filename, &iterator->stats);
 489
 490         if(0 == (iterator->filename = strdup(filename))) {
 491                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 492                 return false;
 493         }
 494         if(0 != tempfile_path_prefix && 0 == (iterator->tempfile_path_prefix = strdup(tempfile_path_prefix))) {
 495                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 496                 return false;
 497         }
 498
 499         return simple_iterator_prime_input_(iterator, read_only);
 500 }
 501
 502 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_is_writable(const FLAC__Metadata_SimpleIterator *iterator)
 503 {
 504         FLAC__ASSERT(0 != iterator);
 505         FLAC__ASSERT(0 != iterator->file);
 506
 507         return iterator->is_writable;
 508 }
 509
 510 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_next(FLAC__Metadata_SimpleIterator *iterator)
 511 {
 512         FLAC__ASSERT(0 != iterator);
 513         FLAC__ASSERT(0 != iterator->file);
 514
 515         if(iterator->is_last)
 516                 return false;
 517
 518         if(0 != fseeko(iterator->file, iterator->length, SEEK_CUR)) {
 519                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 520                 return false;
 521         }
 522
 523         iterator->offset[iterator->depth] = ftello(iterator->file);
 524
 525         return read_metadata_block_header_(iterator);
 526 }
 527
 528 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_prev(FLAC__Metadata_SimpleIterator *iterator)
 529 {
 530         FLAC__off_t this_offset;
 531
 532         FLAC__ASSERT(0 != iterator);
 533         FLAC__ASSERT(0 != iterator->file);
 534
 535         if(iterator->offset[iterator->depth] == iterator->first_offset)
 536                 return false;
 537
 538         if(0 != fseeko(iterator->file, iterator->first_offset, SEEK_SET)) {
 539                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 540                 return false;
 541         }
 542         this_offset = iterator->first_offset;
 543         if(!read_metadata_block_header_(iterator))
 544                 return false;
 545
 546         /* we ignore any error from ftello() and catch it in fseeko() */
 547         while(ftello(iterator->file) + (FLAC__off_t)iterator->length < iterator->offset[iterator->depth]) {
 548                 if(0 != fseeko(iterator->file, iterator->length, SEEK_CUR)) {
 549                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 550                         return false;
 551                 }
 552                 this_offset = ftello(iterator->file);
 553                 if(!read_metadata_block_header_(iterator))
 554                         return false;
 555         }
 556
 557         iterator->offset[iterator->depth] = this_offset;
 558
 559         return true;
 560 }
 561
 562 /*@@@@add to tests*/
 563 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_is_last(const FLAC__Metadata_SimpleIterator *iterator)
 564 {
 565         FLAC__ASSERT(0 != iterator);
 566         FLAC__ASSERT(0 != iterator->file);
 567
 568         return iterator->is_last;
 569 }
 570
 571 /*@@@@add to tests*/
 572 FLAC_API off_t FLAC__metadata_simple_iterator_get_block_offset(const FLAC__Metadata_SimpleIterator *iterator)
 573 {
 574         FLAC__ASSERT(0 != iterator);
 575         FLAC__ASSERT(0 != iterator->file);
 576
 577         return iterator->offset[iterator->depth];
 578 }
 579
 580 FLAC_API FLAC__MetadataType FLAC__metadata_simple_iterator_get_block_type(const FLAC__Metadata_SimpleIterator *iterator)
 581 {
 582         FLAC__ASSERT(0 != iterator);
 583         FLAC__ASSERT(0 != iterator->file);
 584
 585         return iterator->type;
 586 }
 587
 588 /*@@@@add to tests*/
 589 FLAC_API unsigned FLAC__metadata_simple_iterator_get_block_length(const FLAC__Metadata_SimpleIterator *iterator)
 590 {
 591         FLAC__ASSERT(0 != iterator);
 592         FLAC__ASSERT(0 != iterator->file);
 593
 594         return iterator->length;
 595 }
 596
 597 /*@@@@add to tests*/
 598 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_get_application_id(FLAC__Metadata_SimpleIterator *iterator, FLAC__byte *id)
 599 {
 600         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
 601
 602         FLAC__ASSERT(0 != iterator);
 603         FLAC__ASSERT(0 != iterator->file);
 604         FLAC__ASSERT(0 != id);
 605
 606         if(iterator->type != FLAC__METADATA_TYPE_APPLICATION) {
 607                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 608                 return false;
 609         }
 610
 611         if(fread(id, 1, id_bytes, iterator->file) != id_bytes) {
 612                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
 613                 return false;
 614         }
 615
 616         /* back up */
 617         if(0 != fseeko(iterator->file, -((int)id_bytes), SEEK_CUR)) {
 618                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 619                 return false;
 620         }
 621
 622         return true;
 623 }
 624
 625 FLAC_API FLAC__StreamMetadata *FLAC__metadata_simple_iterator_get_block(FLAC__Metadata_SimpleIterator *iterator)
 626 {
 627         FLAC__StreamMetadata *block = FLAC__metadata_object_new(iterator->type);
 628
 629         FLAC__ASSERT(0 != iterator);
 630         FLAC__ASSERT(0 != iterator->file);
 631
 632         if(0 != block) {
 633                 block->is_last = iterator->is_last;
 634                 block->length = iterator->length;
 635
 636                 if(!read_metadata_block_data_(iterator, block)) {
 637                         FLAC__metadata_object_delete(block);
 638                         return 0;
 639                 }
 640
 641                 /* back up to the beginning of the block data to stay consistent */
 642                 if(0 != fseeko(iterator->file, iterator->offset[iterator->depth] + FLAC__STREAM_METADATA_HEADER_LENGTH, SEEK_SET)) {
 643                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 644                         FLAC__metadata_object_delete(block);
 645                         return 0;
 646                 }
 647         }
 648         else
 649                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 650
 651         return block;
 652 }
 653
 654 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_set_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding)
 655 {
 656         FLAC__ASSERT_DECLARATION(FLAC__off_t debug_target_offset = iterator->offset[iterator->depth];)
 657         FLAC__bool ret;
 658
 659         FLAC__ASSERT(0 != iterator);
 660         FLAC__ASSERT(0 != iterator->file);
 661         FLAC__ASSERT(0 != block);
 662
 663         if(!iterator->is_writable) {
 664                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE;
 665                 return false;
 666         }
 667
 668         if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO || block->type == FLAC__METADATA_TYPE_STREAMINFO) {
 669                 if(iterator->type != block->type) {
 670                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 671                         return false;
 672                 }
 673         }
 674
 675         block->is_last = iterator->is_last;
 676
 677         if(iterator->length == block->length)
 678                 return write_metadata_block_stationary_(iterator, block);
 679         else if(iterator->length > block->length) {
 680                 if(use_padding && iterator->length >= FLAC__STREAM_METADATA_HEADER_LENGTH + block->length) {
 681                         ret = write_metadata_block_stationary_with_padding_(iterator, block, iterator->length - FLAC__STREAM_METADATA_HEADER_LENGTH - block->length, block->is_last);
 682                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 683                         FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 684                         return ret;
 685                 }
 686                 else {
 687                         ret = rewrite_whole_file_(iterator, block, /*append=*/false);
 688                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 689                         FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 690                         return ret;
 691                 }
 692         }
 693         else /* iterator->length < block->length */ {
 694                 unsigned padding_leftover = 0;
 695                 FLAC__bool padding_is_last = false;
 696                 if(use_padding) {
 697                         /* first see if we can even use padding */
 698                         if(iterator->is_last) {
 699                                 use_padding = false;
 700                         }
 701                         else {
 702                                 const unsigned extra_padding_bytes_required = block->length - iterator->length;
 703                                 simple_iterator_push_(iterator);
 704                                 if(!FLAC__metadata_simple_iterator_next(iterator)) {
 705                                         (void)simple_iterator_pop_(iterator);
 706                                         return false;
 707                                 }
 708                                 if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
 709                                         use_padding = false;
 710                                 }
 711                                 else {
 712                                         if(FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length == extra_padding_bytes_required) {
 713                                                 padding_leftover = 0;
 714                                                 block->is_last = iterator->is_last;
 715                                         }
 716                                         else if(iterator->length < extra_padding_bytes_required)
 717                                                 use_padding = false;
 718                                         else {
 719                                                 padding_leftover = FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length - extra_padding_bytes_required;
 720                                                 padding_is_last = iterator->is_last;
 721                                                 block->is_last = false;
 722                                         }
 723                                 }
 724                                 if(!simple_iterator_pop_(iterator))
 725                                         return false;
 726                         }
 727                 }
 728                 if(use_padding) {
 729                         if(padding_leftover == 0) {
 730                                 ret = write_metadata_block_stationary_(iterator, block);
 731                                 FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 732                                 FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 733                                 return ret;
 734                         }
 735                         else {
 736                                 FLAC__ASSERT(padding_leftover >= FLAC__STREAM_METADATA_HEADER_LENGTH);
 737                                 ret = write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover - FLAC__STREAM_METADATA_HEADER_LENGTH, padding_is_last);
 738                                 FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 739                                 FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 740                                 return ret;
 741                         }
 742                 }
 743                 else {
 744                         ret = rewrite_whole_file_(iterator, block, /*append=*/false);
 745                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 746                         FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 747                         return ret;
 748                 }
 749         }
 750 }
 751
 752 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_insert_block_after(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding)
 753 {
 754         unsigned padding_leftover = 0;
 755         FLAC__bool padding_is_last = false;
 756
 757         FLAC__ASSERT_DECLARATION(FLAC__off_t debug_target_offset = iterator->offset[iterator->depth] + FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length;)
 758         FLAC__bool ret;
 759
 760         FLAC__ASSERT(0 != iterator);
 761         FLAC__ASSERT(0 != iterator->file);
 762         FLAC__ASSERT(0 != block);
 763
 764         if(!iterator->is_writable)
 765                 return false;
 766
 767         if(block->type == FLAC__METADATA_TYPE_STREAMINFO) {
 768                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 769                 return false;
 770         }
 771
 772         block->is_last = iterator->is_last;
 773
 774         if(use_padding) {
 775                 /* first see if we can even use padding */
 776                 if(iterator->is_last) {
 777                         use_padding = false;
 778                 }
 779                 else {
 780                         simple_iterator_push_(iterator);
 781                         if(!FLAC__metadata_simple_iterator_next(iterator)) {
 782                                 (void)simple_iterator_pop_(iterator);
 783                                 return false;
 784                         }
 785                         if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
 786                                 use_padding = false;
 787                         }
 788                         else {
 789                                 if(iterator->length == block->length) {
 790                                         padding_leftover = 0;
 791                                         block->is_last = iterator->is_last;
 792                                 }
 793                                 else if(iterator->length < FLAC__STREAM_METADATA_HEADER_LENGTH + block->length)
 794                                         use_padding = false;
 795                                 else {
 796                                         padding_leftover = iterator->length - block->length;
 797                                         padding_is_last = iterator->is_last;
 798                                         block->is_last = false;
 799                                 }
 800                         }
 801                         if(!simple_iterator_pop_(iterator))
 802                                 return false;
 803                 }
 804         }
 805         if(use_padding) {
 806                 /* move to the next block, which is suitable padding */
 807                 if(!FLAC__metadata_simple_iterator_next(iterator))
 808                         return false;
 809                 if(padding_leftover == 0) {
 810                         ret = write_metadata_block_stationary_(iterator, block);
 811                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 812                         FLAC__ASSERT(ftello(iterator->file) == debug_target_offset + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 813                         return ret;
 814                 }
 815                 else {
 816                         FLAC__ASSERT(padding_leftover >= FLAC__STREAM_METADATA_HEADER_LENGTH);
 817                         ret = write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover - FLAC__STREAM_METADATA_HEADER_LENGTH, padding_is_last);
 818                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 819                         FLAC__ASSERT(ftello(iterator->file) == debug_target_offset + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 820                         return ret;
 821                 }
 822         }
 823         else {
 824                 ret = rewrite_whole_file_(iterator, block, /*append=*/true);
 825                 FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 826                 FLAC__ASSERT(ftello(iterator->file) == debug_target_offset + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 827                 return ret;
 828         }
 829 }
 830
 831 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_delete_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool use_padding)
 832 {
 833         FLAC__ASSERT_DECLARATION(FLAC__off_t debug_target_offset = iterator->offset[iterator->depth];)
 834         FLAC__bool ret;
 835
 836         if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO) {
 837                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 838                 return false;
 839         }
 840
 841         if(use_padding) {
 842                 FLAC__StreamMetadata *padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING);
 843                 if(0 == padding) {
 844                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 845                         return false;
 846                 }
 847                 padding->length = iterator->length;
 848                 if(!FLAC__metadata_simple_iterator_set_block(iterator, padding, false)) {
 849                         FLAC__metadata_object_delete(padding);
 850                         return false;
 851                 }
 852                 FLAC__metadata_object_delete(padding);
 853                 if(!FLAC__metadata_simple_iterator_prev(iterator))
 854                         return false;
 855                 FLAC__ASSERT(iterator->offset[iterator->depth] + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (FLAC__off_t)iterator->length == debug_target_offset);
 856                 FLAC__ASSERT(ftello(iterator->file) + (FLAC__off_t)iterator->length == debug_target_offset);
 857                 return true;
 858         }
 859         else {
 860                 ret = rewrite_whole_file_(iterator, 0, /*append=*/false);
 861                 FLAC__ASSERT(iterator->offset[iterator->depth] + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (FLAC__off_t)iterator->length == debug_target_offset);
 862                 FLAC__ASSERT(ftello(iterator->file) + (FLAC__off_t)iterator->length == debug_target_offset);
 863                 return ret;
 864         }
 865 }
 866
 867
 868
 869 /****************************************************************************
 870  *
 871  * Level 2 implementation
 872  *
 873  ***************************************************************************/
 874
 875
 876 typedef struct FLAC__Metadata_Node {
 877         FLAC__StreamMetadata *data;
 878         struct FLAC__Metadata_Node *prev, *next;
 879 } FLAC__Metadata_Node;
 880
 881 struct FLAC__Metadata_Chain {
 882         char *filename; /* will be NULL if using callbacks */
 883         FLAC__bool is_ogg;
 884         FLAC__Metadata_Node *head;
 885         FLAC__Metadata_Node *tail;
 886         unsigned nodes;
 887         FLAC__Metadata_ChainStatus status;
 888         FLAC__off_t first_offset, last_offset;
 889         /*
 890          * This is the length of the chain initially read from the FLAC file.
 891          * it is used to compare against the current length to decide whether
 892          * or not the whole file has to be rewritten.
 893          */
 894         FLAC__off_t initial_length;
 895         /* @@@ hacky, these are currently only needed by ogg reader */
 896         FLAC__IOHandle handle;
 897         FLAC__IOCallback_Read read_cb;
 898 };
 899
 900 struct FLAC__Metadata_Iterator {
 901         FLAC__Metadata_Chain *chain;
 902         FLAC__Metadata_Node *current;
 903 };
 904
 905 FLAC_API const char * const FLAC__Metadata_ChainStatusString[] = {
 906         "FLAC__METADATA_CHAIN_STATUS_OK",
 907         "FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT",
 908         "FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE",
 909         "FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE",
 910         "FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE",
 911         "FLAC__METADATA_CHAIN_STATUS_BAD_METADATA",
 912         "FLAC__METADATA_CHAIN_STATUS_READ_ERROR",
 913         "FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR",
 914         "FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR",
 915         "FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR",
 916         "FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR",
 917         "FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR",
 918         "FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR",
 919         "FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS",
 920         "FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH",
 921         "FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL"
 922 };
 923
 924
 925 static FLAC__Metadata_Node *node_new_(void)
 926 {
 927         return calloc(1, sizeof(FLAC__Metadata_Node));
 928 }
 929
 930 static void node_delete_(FLAC__Metadata_Node *node)
 931 {
 932         FLAC__ASSERT(0 != node);
 933         if(0 != node->data)
 934                 FLAC__metadata_object_delete(node->data);
 935         free(node);
 936 }
 937
 938 static void chain_init_(FLAC__Metadata_Chain *chain)
 939 {
 940         FLAC__ASSERT(0 != chain);
 941
 942         chain->filename = 0;
 943         chain->is_ogg = false;
 944         chain->head = chain->tail = 0;
 945         chain->nodes = 0;
 946         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
 947         chain->initial_length = 0;
 948         chain->read_cb = 0;
 949 }
 950
 951 static void chain_clear_(FLAC__Metadata_Chain *chain)
 952 {
 953         FLAC__Metadata_Node *node, *next;
 954
 955         FLAC__ASSERT(0 != chain);
 956
 957         for(node = chain->head; node; ) {
 958                 next = node->next;
 959                 node_delete_(node);
 960                 node = next;
 961         }
 962
 963         if(0 != chain->filename)
 964                 free(chain->filename);
 965
 966         chain_init_(chain);
 967 }
 968
 969 static void chain_append_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 970 {
 971         FLAC__ASSERT(0 != chain);
 972         FLAC__ASSERT(0 != node);
 973         FLAC__ASSERT(0 != node->data);
 974
 975         node->next = node->prev = 0;
 976         node->data->is_last = true;
 977         if(0 != chain->tail)
 978                 chain->tail->data->is_last = false;
 979
 980         if(0 == chain->head)
 981                 chain->head = node;
 982         else {
 983                 FLAC__ASSERT(0 != chain->tail);
 984                 chain->tail->next = node;
 985                 node->prev = chain->tail;
 986         }
 987         chain->tail = node;
 988         chain->nodes++;
 989 }
 990
 991 static void chain_remove_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 992 {
 993         FLAC__ASSERT(0 != chain);
 994         FLAC__ASSERT(0 != node);
 995
 996         if(node == chain->head)
 997                 chain->head = node->next;
 998         else
 999                 node->prev->next = node->next;
1000
1001         if(node == chain->tail)
1002                 chain->tail = node->prev;
1003         else
1004                 node->next->prev = node->prev;
1005
1006         if(0 != chain->tail)
1007                 chain->tail->data->is_last = true;
1008
1009         chain->nodes--;
1010 }
1011
1012 static void chain_delete_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
1013 {
1014         chain_remove_node_(chain, node);
1015         node_delete_(node);
1016 }
1017
1018 static FLAC__off_t chain_calculate_length_(FLAC__Metadata_Chain *chain)
1019 {
1020         const FLAC__Metadata_Node *node;
1021         FLAC__off_t length = 0;
1022         for(node = chain->head; node; node = node->next)
1023                 length += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1024         return length;
1025 }
1026
1027 static void iterator_insert_node_(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Node *node)
1028 {
1029         FLAC__ASSERT(0 != node);
1030         FLAC__ASSERT(0 != node->data);
1031         FLAC__ASSERT(0 != iterator);
1032         FLAC__ASSERT(0 != iterator->current);
1033         FLAC__ASSERT(0 != iterator->chain);
1034         FLAC__ASSERT(0 != iterator->chain->head);
1035         FLAC__ASSERT(0 != iterator->chain->tail);
1036
1037         node->data->is_last = false;
1038
1039         node->prev = iterator->current->prev;
1040         node->next = iterator->current;
1041
1042         if(0 == node->prev)
1043                 iterator->chain->head = node;
1044         else
1045                 node->prev->next = node;
1046
1047         iterator->current->prev = node;
1048
1049         iterator->chain->nodes++;
1050 }
1051
1052 static void iterator_insert_node_after_(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Node *node)
1053 {
1054         FLAC__ASSERT(0 != node);
1055         FLAC__ASSERT(0 != node->data);
1056         FLAC__ASSERT(0 != iterator);
1057         FLAC__ASSERT(0 != iterator->current);
1058         FLAC__ASSERT(0 != iterator->chain);
1059         FLAC__ASSERT(0 != iterator->chain->head);
1060         FLAC__ASSERT(0 != iterator->chain->tail);
1061
1062         iterator->current->data->is_last = false;
1063
1064         node->prev = iterator->current;
1065         node->next = iterator->current->next;
1066
1067         if(0 == node->next)
1068                 iterator->chain->tail = node;
1069         else
1070                 node->next->prev = node;
1071
1072         node->prev->next = node;
1073
1074         iterator->chain->tail->data->is_last = true;
1075
1076         iterator->chain->nodes++;
1077 }
1078
1079 /* return true iff node and node->next are both padding */
1080 static FLAC__bool chain_merge_adjacent_padding_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
1081 {
1082         if(node->data->type == FLAC__METADATA_TYPE_PADDING && 0 != node->next && node->next->data->type == FLAC__METADATA_TYPE_PADDING) {
1083                 const unsigned growth = FLAC__STREAM_METADATA_HEADER_LENGTH + node->next->data->length;
1084                 node->data->length += growth;
1085
1086                 chain_delete_node_(chain, node->next);
1087                 return true;
1088         }
1089         else
1090                 return false;
1091 }
1092
1093 /* Returns the new length of the chain, or 0 if there was an error. */
1094 /* WATCHOUT: This can get called multiple times before a write, so
1095  * it should still work when this happens.
1096  */
1097 /* WATCHOUT: Make sure to also update the logic in
1098  * FLAC__metadata_chain_check_if_tempfile_needed() if the logic here changes.
1099  */
1100 static FLAC__off_t chain_prepare_for_write_(FLAC__Metadata_Chain *chain, FLAC__bool use_padding)
1101 {
1102         FLAC__off_t current_length = chain_calculate_length_(chain);
1103
1104         if(use_padding) {
1105                 /* if the metadata shrank and the last block is padding, we just extend the last padding block */
1106                 if(current_length < chain->initial_length && chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1107                         const FLAC__off_t delta = chain->initial_length - current_length;
1108                         chain->tail->data->length += delta;
1109                         current_length += delta;
1110                         FLAC__ASSERT(current_length == chain->initial_length);
1111                 }
1112                 /* if the metadata shrank more than 4 bytes then there's room to add another padding block */
1113                 else if(current_length + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH <= chain->initial_length) {
1114                         FLAC__StreamMetadata *padding;
1115                         FLAC__Metadata_Node *node;
1116                         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING))) {
1117                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1118                                 return 0;
1119                         }
1120                         padding->length = chain->initial_length - (FLAC__STREAM_METADATA_HEADER_LENGTH + current_length);
1121                         if(0 == (node = node_new_())) {
1122                                 FLAC__metadata_object_delete(padding);
1123                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1124                                 return 0;
1125                         }
1126                         node->data = padding;
1127                         chain_append_node_(chain, node);
1128                         current_length = chain_calculate_length_(chain);
1129                         FLAC__ASSERT(current_length == chain->initial_length);
1130                 }
1131                 /* if the metadata grew but the last block is padding, try cutting the padding to restore the original length so we don't have to rewrite the whole file */
1132                 else if(current_length > chain->initial_length) {
1133                         const FLAC__off_t delta = current_length - chain->initial_length;
1134                         if(chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1135                                 /* if the delta is exactly the size of the last padding block, remove the padding block */
1136                                 if((FLAC__off_t)chain->tail->data->length + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH == delta) {
1137                                         chain_delete_node_(chain, chain->tail);
1138                                         current_length = chain_calculate_length_(chain);
1139                                         FLAC__ASSERT(current_length == chain->initial_length);
1140                                 }
1141                                 /* if there is at least 'delta' bytes of padding, trim the padding down */
1142                                 else if((FLAC__off_t)chain->tail->data->length >= delta) {
1143                                         chain->tail->data->length -= delta;
1144                                         current_length -= delta;
1145                                         FLAC__ASSERT(current_length == chain->initial_length);
1146                                 }
1147                         }
1148                 }
1149         }
1150
1151         return current_length;
1152 }
1153
1154 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)
1155 {
1156         FLAC__Metadata_Node *node;
1157
1158         FLAC__ASSERT(0 != chain);
1159
1160         /* we assume we're already at the beginning of the file */
1161
1162         switch(seek_to_first_metadata_block_cb_(handle, read_cb, seek_cb)) {
1163                 case 0:
1164                         break;
1165                 case 1:
1166                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1167                         return false;
1168                 case 2:
1169                         chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1170                         return false;
1171                 case 3:
1172                         chain->status = FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE;
1173                         return false;
1174                 default:
1175                         FLAC__ASSERT(0);
1176                         return false;
1177         }
1178
1179         {
1180                 FLAC__int64 pos = tell_cb(handle);
1181                 if(pos < 0) {
1182                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1183                         return false;
1184                 }
1185                 chain->first_offset = (FLAC__off_t)pos;
1186         }
1187
1188         {
1189                 FLAC__bool is_last;
1190                 FLAC__MetadataType type;
1191                 unsigned length;
1192
1193                 do {
1194                         node = node_new_();
1195                         if(0 == node) {
1196                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1197                                 return false;
1198                         }
1199
1200                         if(!read_metadata_block_header_cb_(handle, read_cb, &is_last, &type, &length)) {
1201                                 node_delete_(node);
1202                                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1203                                 return false;
1204                         }
1205
1206                         node->data = FLAC__metadata_object_new(type);
1207                         if(0 == node->data) {
1208                                 node_delete_(node);
1209                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1210                                 return false;
1211                         }
1212
1213                         node->data->is_last = is_last;
1214                         node->data->length = length;
1215
1216                         chain->status = get_equivalent_status_(read_metadata_block_data_cb_(handle, read_cb, seek_cb, node->data));
1217                         if(chain->status != FLAC__METADATA_CHAIN_STATUS_OK) {
1218                                 node_delete_(node);
1219                                 return false;
1220                         }
1221                         chain_append_node_(chain, node);
1222                 } while(!is_last);
1223         }
1224
1225         {
1226                 FLAC__int64 pos = tell_cb(handle);
1227                 if(pos < 0) {
1228                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1229                         return false;
1230                 }
1231                 chain->last_offset = (FLAC__off_t)pos;
1232         }
1233
1234         chain->initial_length = chain_calculate_length_(chain);
1235
1236         return true;
1237 }
1238
1239 static FLAC__StreamDecoderReadStatus chain_read_ogg_read_cb_(const FLAC__StreamDecoder *decoder, FLAC__byte buffer[], size_t *bytes, void *client_data)
1240 {
1241         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1242         (void)decoder;
1243         if(*bytes > 0 && chain->status == FLAC__METADATA_CHAIN_STATUS_OK) {
1244                 *bytes = chain->read_cb(buffer, sizeof(FLAC__byte), *bytes, chain->handle);
1245                 if(*bytes == 0)
1246                         return FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM;
1247                 else
1248                         return FLAC__STREAM_DECODER_READ_STATUS_CONTINUE;
1249         }
1250         else
1251                 return FLAC__STREAM_DECODER_READ_STATUS_ABORT;
1252 }
1253
1254 static FLAC__StreamDecoderWriteStatus chain_read_ogg_write_cb_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
1255 {
1256         (void)decoder, (void)frame, (void)buffer, (void)client_data;
1257         return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
1258 }
1259
1260 static void chain_read_ogg_metadata_cb_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
1261 {
1262         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1263         FLAC__Metadata_Node *node;
1264
1265         (void)decoder;
1266
1267         node = node_new_();
1268         if(0 == node) {
1269                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1270                 return;
1271         }
1272
1273         node->data = FLAC__metadata_object_clone(metadata);
1274         if(0 == node->data) {
1275                 node_delete_(node);
1276                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1277                 return;
1278         }
1279
1280         chain_append_node_(chain, node);
1281 }
1282
1283 static void chain_read_ogg_error_cb_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
1284 {
1285         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1286         (void)decoder, (void)status;
1287         chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1288 }
1289
1290 static FLAC__bool chain_read_ogg_cb_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb)
1291 {
1292         FLAC__StreamDecoder *decoder;
1293
1294         FLAC__ASSERT(0 != chain);
1295
1296         /* we assume we're already at the beginning of the file */
1297
1298         chain->handle = handle;
1299         chain->read_cb = read_cb;
1300         if(0 == (decoder = FLAC__stream_decoder_new())) {
1301                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1302                 return false;
1303         }
1304         FLAC__stream_decoder_set_metadata_respond_all(decoder);
1305         if(FLAC__stream_decoder_init_ogg_stream(decoder, chain_read_ogg_read_cb_, /*seek_callback=*/0, /*tell_callback=*/0, /*length_callback=*/0, /*eof_callback=*/0, chain_read_ogg_write_cb_, chain_read_ogg_metadata_cb_, chain_read_ogg_error_cb_, chain) != FLAC__STREAM_DECODER_INIT_STATUS_OK) {
1306                 FLAC__stream_decoder_delete(decoder);
1307                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1308                 return false;
1309         }
1310
1311         chain->first_offset = 0; /*@@@ wrong; will need to be set correctly to implement metadata writing for Ogg FLAC */
1312
1313         if(!FLAC__stream_decoder_process_until_end_of_metadata(decoder))
1314                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1315         if(chain->status != FLAC__METADATA_CHAIN_STATUS_OK) {
1316                 FLAC__stream_decoder_delete(decoder);
1317                 return false;
1318         }
1319
1320         FLAC__stream_decoder_delete(decoder);
1321
1322         chain->last_offset = 0; /*@@@ wrong; will need to be set correctly to implement metadata writing for Ogg FLAC */
1323
1324         chain->initial_length = chain_calculate_length_(chain);
1325
1326         return true;
1327 }
1328
1329 static FLAC__bool chain_rewrite_metadata_in_place_cb_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, FLAC__IOCallback_Seek seek_cb)
1330 {
1331         FLAC__Metadata_Node *node;
1332
1333         FLAC__ASSERT(0 != chain);
1334         FLAC__ASSERT(0 != chain->head);
1335
1336         if(0 != seek_cb(handle, chain->first_offset, SEEK_SET)) {
1337                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1338                 return false;
1339         }
1340
1341         for(node = chain->head; node; node = node->next) {
1342                 if(!write_metadata_block_header_cb_(handle, write_cb, node->data)) {
1343                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1344                         return false;
1345                 }
1346                 if(!write_metadata_block_data_cb_(handle, write_cb, node->data)) {
1347                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1348                         return false;
1349                 }
1350         }
1351
1352         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1353
1354         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
1355         return true;
1356 }
1357
1358 static FLAC__bool chain_rewrite_metadata_in_place_(FLAC__Metadata_Chain *chain)
1359 {
1360         FILE *file;
1361         FLAC__bool ret;
1362
1363         FLAC__ASSERT(0 != chain->filename);
1364
1365         if(0 == (file = fopen(chain->filename, "r+b"))) {
1366                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1367                 return false;
1368         }
1369
1370         /* chain_rewrite_metadata_in_place_cb_() sets chain->status for us */
1371         ret = chain_rewrite_metadata_in_place_cb_(chain, (FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, fseek_wrapper_);
1372
1373         fclose(file);
1374
1375         return ret;
1376 }
1377
1378 static FLAC__bool chain_rewrite_file_(FLAC__Metadata_Chain *chain, const char *tempfile_path_prefix)
1379 {
1380         FILE *f, *tempfile;
1381         char *tempfilename;
1382         FLAC__Metadata_SimpleIteratorStatus status;
1383         const FLAC__Metadata_Node *node;
1384
1385         FLAC__ASSERT(0 != chain);
1386         FLAC__ASSERT(0 != chain->filename);
1387         FLAC__ASSERT(0 != chain->head);
1388
1389         /* copy the file prefix (data up to first metadata block */
1390         if(0 == (f = fopen(chain->filename, "rb"))) {
1391                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1392                 return false;
1393         }
1394         if(!open_tempfile_(chain->filename, tempfile_path_prefix, &tempfile, &tempfilename, &status)) {
1395                 chain->status = get_equivalent_status_(status);
1396                 goto err;
1397         }
1398         if(!copy_n_bytes_from_file_(f, tempfile, chain->first_offset, &status)) {
1399                 chain->status = get_equivalent_status_(status);
1400                 goto err;
1401         }
1402
1403         /* write the metadata */
1404         for(node = chain->head; node; node = node->next) {
1405                 if(!write_metadata_block_header_(tempfile, &status, node->data)) {
1406                         chain->status = get_equivalent_status_(status);
1407                         goto err;
1408                 }
1409                 if(!write_metadata_block_data_(tempfile, &status, node->data)) {
1410                         chain->status = get_equivalent_status_(status);
1411                         goto err;
1412                 }
1413         }
1414         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1415
1416         /* copy the file postfix (everything after the metadata) */
1417         if(0 != fseeko(f, chain->last_offset, SEEK_SET)) {
1418                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1419                 goto err;
1420         }
1421         if(!copy_remaining_bytes_from_file_(f, tempfile, &status)) {
1422                 chain->status = get_equivalent_status_(status);
1423                 goto err;
1424         }
1425
1426         /* move the tempfile on top of the original */
1427         (void)fclose(f);
1428         if(!transport_tempfile_(chain->filename, &tempfile, &tempfilename, &status))
1429                 return false;
1430
1431         return true;
1432
1433 err:
1434         (void)fclose(f);
1435         cleanup_tempfile_(&tempfile, &tempfilename);
1436         return false;
1437 }
1438
1439 /* assumes 'handle' is already at beginning of file */
1440 static FLAC__bool chain_rewrite_file_cb_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb, FLAC__IOCallback_Eof eof_cb, FLAC__IOHandle temp_handle, FLAC__IOCallback_Write temp_write_cb)
1441 {
1442         FLAC__Metadata_SimpleIteratorStatus status;
1443         const FLAC__Metadata_Node *node;
1444
1445         FLAC__ASSERT(0 != chain);
1446         FLAC__ASSERT(0 == chain->filename);
1447         FLAC__ASSERT(0 != chain->head);
1448
1449         /* copy the file prefix (data up to first metadata block */
1450         if(!copy_n_bytes_from_file_cb_(handle, read_cb, temp_handle, temp_write_cb, chain->first_offset, &status)) {
1451                 chain->status = get_equivalent_status_(status);
1452                 return false;
1453         }
1454
1455         /* write the metadata */
1456         for(node = chain->head; node; node = node->next) {
1457                 if(!write_metadata_block_header_cb_(temp_handle, temp_write_cb, node->data)) {
1458                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1459                         return false;
1460                 }
1461                 if(!write_metadata_block_data_cb_(temp_handle, temp_write_cb, node->data)) {
1462                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1463                         return false;
1464                 }
1465         }
1466         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1467
1468         /* copy the file postfix (everything after the metadata) */
1469         if(0 != seek_cb(handle, chain->last_offset, SEEK_SET)) {
1470                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1471                 return false;
1472         }
1473         if(!copy_remaining_bytes_from_file_cb_(handle, read_cb, eof_cb, temp_handle, temp_write_cb, &status)) {
1474                 chain->status = get_equivalent_status_(status);
1475                 return false;
1476         }
1477
1478         return true;
1479 }
1480
1481 FLAC_API FLAC__Metadata_Chain *FLAC__metadata_chain_new(void)
1482 {
1483         FLAC__Metadata_Chain *chain = calloc(1, sizeof(FLAC__Metadata_Chain));
1484
1485         if(0 != chain)
1486                 chain_init_(chain);
1487
1488         return chain;
1489 }
1490
1491 FLAC_API void FLAC__metadata_chain_delete(FLAC__Metadata_Chain *chain)
1492 {
1493         FLAC__ASSERT(0 != chain);
1494
1495         chain_clear_(chain);
1496
1497         free(chain);
1498 }
1499
1500 FLAC_API FLAC__Metadata_ChainStatus FLAC__metadata_chain_status(FLAC__Metadata_Chain *chain)
1501 {
1502         FLAC__Metadata_ChainStatus status;
1503
1504         FLAC__ASSERT(0 != chain);
1505
1506         status = chain->status;
1507         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
1508         return status;
1509 }
1510
1511 static FLAC__bool chain_read_(FLAC__Metadata_Chain *chain, const char *filename, FLAC__bool is_ogg)
1512 {
1513         FILE *file;
1514         FLAC__bool ret;
1515
1516         FLAC__ASSERT(0 != chain);
1517         FLAC__ASSERT(0 != filename);
1518
1519         chain_clear_(chain);
1520
1521         if(0 == (chain->filename = strdup(filename))) {
1522                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1523                 return false;
1524         }
1525
1526         chain->is_ogg = is_ogg;
1527
1528         if(0 == (file = fopen(filename, "rb"))) {
1529                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1530                 return false;
1531         }
1532
1533         /* the function also sets chain->status for us */
1534         ret = is_ogg?
1535                 chain_read_ogg_cb_(chain, file, (FLAC__IOCallback_Read)fread) :
1536                 chain_read_cb_(chain, file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, ftell_wrapper_)
1537         ;
1538
1539         fclose(file);
1540
1541         return ret;
1542 }
1543
1544 FLAC_API FLAC__bool FLAC__metadata_chain_read(FLAC__Metadata_Chain *chain, const char *filename)
1545 {
1546         return chain_read_(chain, filename, /*is_ogg=*/false);
1547 }
1548
1549 /*@@@@add to tests*/
1550 FLAC_API FLAC__bool FLAC__metadata_chain_read_ogg(FLAC__Metadata_Chain *chain, const char *filename)
1551 {
1552         return chain_read_(chain, filename, /*is_ogg=*/true);
1553 }
1554
1555 static FLAC__bool chain_read_with_callbacks_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks, FLAC__bool is_ogg)
1556 {
1557         FLAC__bool ret;
1558
1559         FLAC__ASSERT(0 != chain);
1560
1561         chain_clear_(chain);
1562
1563         if (0 == callbacks.read || 0 == callbacks.seek || 0 == callbacks.tell) {
1564                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1565                 return false;
1566         }
1567
1568         chain->is_ogg = is_ogg;
1569
1570         /* rewind */
1571         if(0 != callbacks.seek(handle, 0, SEEK_SET)) {
1572                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1573                 return false;
1574         }
1575
1576         /* the function also sets chain->status for us */
1577         ret = is_ogg?
1578                 chain_read_ogg_cb_(chain, handle, callbacks.read) :
1579                 chain_read_cb_(chain, handle, callbacks.read, callbacks.seek, callbacks.tell)
1580         ;
1581
1582         return ret;
1583 }
1584
1585 FLAC_API FLAC__bool FLAC__metadata_chain_read_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1586 {
1587         return chain_read_with_callbacks_(chain, handle, callbacks, /*is_ogg=*/false);
1588 }
1589
1590 /*@@@@add to tests*/
1591 FLAC_API FLAC__bool FLAC__metadata_chain_read_ogg_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1592 {
1593         return chain_read_with_callbacks_(chain, handle, callbacks, /*is_ogg=*/true);
1594 }
1595
1596 FLAC_API FLAC__bool FLAC__metadata_chain_check_if_tempfile_needed(FLAC__Metadata_Chain *chain, FLAC__bool use_padding)
1597 {
1598         /* This does all the same checks that are in chain_prepare_for_write_()
1599          * but doesn't actually alter the chain.  Make sure to update the logic
1600          * here if chain_prepare_for_write_() changes.
1601          */
1602         const FLAC__off_t current_length = chain_calculate_length_(chain);
1603
1604         FLAC__ASSERT(0 != chain);
1605
1606         if(use_padding) {
1607                 /* if the metadata shrank and the last block is padding, we just extend the last padding block */
1608                 if(current_length < chain->initial_length && chain->tail->data->type == FLAC__METADATA_TYPE_PADDING)
1609                         return false;
1610                 /* if the metadata shrank more than 4 bytes then there's room to add another padding block */
1611                 else if(current_length + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH <= chain->initial_length)
1612                         return false;
1613                 /* if the metadata grew but the last block is padding, try cutting the padding to restore the original length so we don't have to rewrite the whole file */
1614                 else if(current_length > chain->initial_length) {
1615                         const FLAC__off_t delta = current_length - chain->initial_length;
1616                         if(chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1617                                 /* if the delta is exactly the size of the last padding block, remove the padding block */
1618                                 if((FLAC__off_t)chain->tail->data->length + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH == delta)
1619                                         return false;
1620                                 /* if there is at least 'delta' bytes of padding, trim the padding down */
1621                                 else if((FLAC__off_t)chain->tail->data->length >= delta)
1622                                         return false;
1623                         }
1624                 }
1625         }
1626
1627         return (current_length != chain->initial_length);
1628 }
1629
1630 FLAC_API FLAC__bool FLAC__metadata_chain_write(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__bool preserve_file_stats)
1631 {
1632         struct stat stats;
1633         const char *tempfile_path_prefix = 0;
1634         FLAC__off_t current_length;
1635
1636         FLAC__ASSERT(0 != chain);
1637
1638         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1639                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1640                 return false;
1641         }
1642
1643         if (0 == chain->filename) {
1644                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1645                 return false;
1646         }
1647
1648         current_length = chain_prepare_for_write_(chain, use_padding);
1649
1650         /* a return value of 0 means there was an error; chain->status is already set */
1651         if (0 == current_length)
1652                 return false;
1653
1654         if(preserve_file_stats)
1655                 get_file_stats_(chain->filename, &stats);
1656
1657         if(current_length == chain->initial_length) {
1658                 if(!chain_rewrite_metadata_in_place_(chain))
1659                         return false;
1660         }
1661         else {
1662                 if(!chain_rewrite_file_(chain, tempfile_path_prefix))
1663                         return false;
1664
1665                 /* recompute lengths and offsets */
1666                 {
1667                         const FLAC__Metadata_Node *node;
1668                         chain->initial_length = current_length;
1669                         chain->last_offset = chain->first_offset;
1670                         for(node = chain->head; node; node = node->next)
1671                                 chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1672                 }
1673         }
1674
1675         if(preserve_file_stats)
1676                 set_file_stats_(chain->filename, &stats);
1677
1678         return true;
1679 }
1680
1681 FLAC_API FLAC__bool FLAC__metadata_chain_write_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1682 {
1683         FLAC__off_t current_length;
1684
1685         FLAC__ASSERT(0 != chain);
1686
1687         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1688                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1689                 return false;
1690         }
1691
1692         if (0 != chain->filename) {
1693                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1694                 return false;
1695         }
1696
1697         if (0 == callbacks.write || 0 == callbacks.seek) {
1698                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1699                 return false;
1700         }
1701
1702         if (FLAC__metadata_chain_check_if_tempfile_needed(chain, use_padding)) {
1703                 chain->status = FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL;
1704                 return false;
1705         }
1706
1707         current_length = chain_prepare_for_write_(chain, use_padding);
1708
1709         /* a return value of 0 means there was an error; chain->status is already set */
1710         if (0 == current_length)
1711                 return false;
1712
1713         FLAC__ASSERT(current_length == chain->initial_length);
1714
1715         return chain_rewrite_metadata_in_place_cb_(chain, handle, callbacks.write, callbacks.seek);
1716 }
1717
1718 FLAC_API FLAC__bool FLAC__metadata_chain_write_with_callbacks_and_tempfile(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks, FLAC__IOHandle temp_handle, FLAC__IOCallbacks temp_callbacks)
1719 {
1720         FLAC__off_t current_length;
1721
1722         FLAC__ASSERT(0 != chain);
1723
1724         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1725                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1726                 return false;
1727         }
1728
1729         if (0 != chain->filename) {
1730                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1731                 return false;
1732         }
1733
1734         if (0 == callbacks.read || 0 == callbacks.seek || 0 == callbacks.eof) {
1735                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1736                 return false;
1737         }
1738         if (0 == temp_callbacks.write) {
1739                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1740                 return false;
1741         }
1742
1743         if (!FLAC__metadata_chain_check_if_tempfile_needed(chain, use_padding)) {
1744                 chain->status = FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL;
1745                 return false;
1746         }
1747
1748         current_length = chain_prepare_for_write_(chain, use_padding);
1749
1750         /* a return value of 0 means there was an error; chain->status is already set */
1751         if (0 == current_length)
1752                 return false;
1753
1754         FLAC__ASSERT(current_length != chain->initial_length);
1755
1756         /* rewind */
1757         if(0 != callbacks.seek(handle, 0, SEEK_SET)) {
1758                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1759                 return false;
1760         }
1761
1762         if(!chain_rewrite_file_cb_(chain, handle, callbacks.read, callbacks.seek, callbacks.eof, temp_handle, temp_callbacks.write))
1763                 return false;
1764
1765         /* recompute lengths and offsets */
1766         {
1767                 const FLAC__Metadata_Node *node;
1768                 chain->initial_length = current_length;
1769                 chain->last_offset = chain->first_offset;
1770                 for(node = chain->head; node; node = node->next)
1771                         chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1772         }
1773
1774         return true;
1775 }
1776
1777 FLAC_API void FLAC__metadata_chain_merge_padding(FLAC__Metadata_Chain *chain)
1778 {
1779         FLAC__Metadata_Node *node;
1780
1781         FLAC__ASSERT(0 != chain);
1782
1783         for(node = chain->head; node; ) {
1784                 if(!chain_merge_adjacent_padding_(chain, node))
1785                         node = node->next;
1786         }
1787 }
1788
1789 FLAC_API void FLAC__metadata_chain_sort_padding(FLAC__Metadata_Chain *chain)
1790 {
1791         FLAC__Metadata_Node *node, *save;
1792         unsigned i;
1793
1794         FLAC__ASSERT(0 != chain);
1795
1796         /*
1797          * Don't try and be too smart... this simple algo is good enough for
1798          * the small number of nodes that we deal with.
1799          */
1800         for(i = 0, node = chain->head; i < chain->nodes; i++) {
1801                 if(node->data->type == FLAC__METADATA_TYPE_PADDING) {
1802                         save = node->next;
1803                         chain_remove_node_(chain, node);
1804                         chain_append_node_(chain, node);
1805                         node = save;
1806                 }
1807                 else {
1808                         node = node->next;
1809                 }
1810         }
1811
1812         FLAC__metadata_chain_merge_padding(chain);
1813 }
1814
1815
1816 FLAC_API FLAC__Metadata_Iterator *FLAC__metadata_iterator_new(void)
1817 {
1818         FLAC__Metadata_Iterator *iterator = calloc(1, sizeof(FLAC__Metadata_Iterator));
1819
1820         /* calloc() implies:
1821                 iterator->current = 0;
1822                 iterator->chain = 0;
1823         */
1824
1825         return iterator;
1826 }
1827
1828 FLAC_API void FLAC__metadata_iterator_delete(FLAC__Metadata_Iterator *iterator)
1829 {
1830         FLAC__ASSERT(0 != iterator);
1831
1832         free(iterator);
1833 }
1834
1835 FLAC_API void FLAC__metadata_iterator_init(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Chain *chain)
1836 {
1837         FLAC__ASSERT(0 != iterator);
1838         FLAC__ASSERT(0 != chain);
1839         FLAC__ASSERT(0 != chain->head);
1840
1841         iterator->chain = chain;
1842         iterator->current = chain->head;
1843 }
1844
1845 FLAC_API FLAC__bool FLAC__metadata_iterator_next(FLAC__Metadata_Iterator *iterator)
1846 {
1847         FLAC__ASSERT(0 != iterator);
1848
1849         if(0 == iterator->current || 0 == iterator->current->next)
1850                 return false;
1851
1852         iterator->current = iterator->current->next;
1853         return true;
1854 }
1855
1856 FLAC_API FLAC__bool FLAC__metadata_iterator_prev(FLAC__Metadata_Iterator *iterator)
1857 {
1858         FLAC__ASSERT(0 != iterator);
1859
1860         if(0 == iterator->current || 0 == iterator->current->prev)
1861                 return false;
1862
1863         iterator->current = iterator->current->prev;
1864         return true;
1865 }
1866
1867 FLAC_API FLAC__MetadataType FLAC__metadata_iterator_get_block_type(const FLAC__Metadata_Iterator *iterator)
1868 {
1869         FLAC__ASSERT(0 != iterator);
1870         FLAC__ASSERT(0 != iterator->current);
1871         FLAC__ASSERT(0 != iterator->current->data);
1872
1873         return iterator->current->data->type;
1874 }
1875
1876 FLAC_API FLAC__StreamMetadata *FLAC__metadata_iterator_get_block(FLAC__Metadata_Iterator *iterator)
1877 {
1878         FLAC__ASSERT(0 != iterator);
1879         FLAC__ASSERT(0 != iterator->current);
1880
1881         return iterator->current->data;
1882 }
1883
1884 FLAC_API FLAC__bool FLAC__metadata_iterator_set_block(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1885 {
1886         FLAC__ASSERT(0 != iterator);
1887         FLAC__ASSERT(0 != block);
1888         return FLAC__metadata_iterator_delete_block(iterator, false) && FLAC__metadata_iterator_insert_block_after(iterator, block);
1889 }
1890
1891 FLAC_API FLAC__bool FLAC__metadata_iterator_delete_block(FLAC__Metadata_Iterator *iterator, FLAC__bool replace_with_padding)
1892 {
1893         FLAC__Metadata_Node *save;
1894
1895         FLAC__ASSERT(0 != iterator);
1896         FLAC__ASSERT(0 != iterator->current);
1897
1898         if(0 == iterator->current->prev) {
1899                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1900                 return false;
1901         }
1902
1903         save = iterator->current->prev;
1904
1905         if(replace_with_padding) {
1906                 FLAC__metadata_object_delete_data(iterator->current->data);
1907                 iterator->current->data->type = FLAC__METADATA_TYPE_PADDING;
1908         }
1909         else {
1910                 chain_delete_node_(iterator->chain, iterator->current);
1911         }
1912
1913         iterator->current = save;
1914         return true;
1915 }
1916
1917 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_before(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1918 {
1919         FLAC__Metadata_Node *node;
1920
1921         FLAC__ASSERT(0 != iterator);
1922         FLAC__ASSERT(0 != iterator->current);
1923         FLAC__ASSERT(0 != block);
1924
1925         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1926                 return false;
1927
1928         if(0 == iterator->current->prev) {
1929                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1930                 return false;
1931         }
1932
1933         if(0 == (node = node_new_()))
1934                 return false;
1935
1936         node->data = block;
1937         iterator_insert_node_(iterator, node);
1938         iterator->current = node;
1939         return true;
1940 }
1941
1942 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_after(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1943 {
1944         FLAC__Metadata_Node *node;
1945
1946         FLAC__ASSERT(0 != iterator);
1947         FLAC__ASSERT(0 != iterator->current);
1948         FLAC__ASSERT(0 != block);
1949
1950         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1951                 return false;
1952
1953         if(0 == (node = node_new_()))
1954                 return false;
1955
1956         node->data = block;
1957         iterator_insert_node_after_(iterator, node);
1958         iterator->current = node;
1959         return true;
1960 }
1961
1962
1963 /****************************************************************************
1964  *
1965  * Local function definitions
1966  *
1967  ***************************************************************************/
1968
1969 void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
1970 {
1971         unsigned i;
1972
1973         b += bytes;
1974
1975         for(i = 0; i < bytes; i++) {
1976                 *(--b) = (FLAC__byte)(val & 0xff);
1977                 val >>= 8;
1978         }
1979 }
1980
1981 void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
1982 {
1983         unsigned i;
1984
1985         for(i = 0; i < bytes; i++) {
1986                 *(b++) = (FLAC__byte)(val & 0xff);
1987                 val >>= 8;
1988         }
1989 }
1990
1991 void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes)
1992 {
1993         unsigned i;
1994
1995         b += bytes;
1996
1997         for(i = 0; i < bytes; i++) {
1998                 *(--b) = (FLAC__byte)(val & 0xff);
1999                 val >>= 8;
2000         }
2001 }
2002
2003 FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes)
2004 {
2005         FLAC__uint32 ret = 0;
2006         unsigned i;
2007
2008         for(i = 0; i < bytes; i++)
2009                 ret = (ret << 8) | (FLAC__uint32)(*b++);
2010
2011         return ret;
2012 }
2013
2014 FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes)
2015 {
2016         FLAC__uint32 ret = 0;
2017         unsigned i;
2018
2019         b += bytes;
2020
2021         for(i = 0; i < bytes; i++)
2022                 ret = (ret << 8) | (FLAC__uint32)(*--b);
2023
2024         return ret;
2025 }
2026
2027 FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes)
2028 {
2029         FLAC__uint64 ret = 0;
2030         unsigned i;
2031
2032         for(i = 0; i < bytes; i++)
2033                 ret = (ret << 8) | (FLAC__uint64)(*b++);
2034
2035         return ret;
2036 }
2037
2038 FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator)
2039 {
2040         FLAC__ASSERT(0 != iterator);
2041         FLAC__ASSERT(0 != iterator->file);
2042
2043         if(!read_metadata_block_header_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, &iterator->is_last, &iterator->type, &iterator->length)) {
2044                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2045                 return false;
2046         }
2047
2048         return true;
2049 }
2050
2051 FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block)
2052 {
2053         FLAC__ASSERT(0 != iterator);
2054         FLAC__ASSERT(0 != iterator->file);
2055
2056         iterator->status = read_metadata_block_data_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, block);
2057
2058         return (iterator->status == FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK);
2059 }
2060
2061 FLAC__bool read_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__bool *is_last, FLAC__MetadataType *type, unsigned *length)
2062 {
2063         FLAC__byte raw_header[FLAC__STREAM_METADATA_HEADER_LENGTH];
2064
2065         if(read_cb(raw_header, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
2066                 return false;
2067
2068         *is_last = raw_header[0] & 0x80? true : false;
2069         *type = (FLAC__MetadataType)(raw_header[0] & 0x7f);
2070         *length = unpack_uint32_(raw_header + 1, 3);
2071
2072         /* Note that we don't check:
2073          *    if(iterator->type >= FLAC__METADATA_TYPE_UNDEFINED)
2074          * we just will read in an opaque block
2075          */
2076
2077         return true;
2078 }
2079
2080 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata *block)
2081 {
2082         switch(block->type) {
2083                 case FLAC__METADATA_TYPE_STREAMINFO:
2084                         return read_metadata_block_data_streaminfo_cb_(handle, read_cb, &block->data.stream_info);
2085                 case FLAC__METADATA_TYPE_PADDING:
2086                         return read_metadata_block_data_padding_cb_(handle, seek_cb, &block->data.padding, block->length);
2087                 case FLAC__METADATA_TYPE_APPLICATION:
2088                         return read_metadata_block_data_application_cb_(handle, read_cb, &block->data.application, block->length);
2089                 case FLAC__METADATA_TYPE_SEEKTABLE:
2090                         return read_metadata_block_data_seektable_cb_(handle, read_cb, &block->data.seek_table, block->length);
2091                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
2092                         return read_metadata_block_data_vorbis_comment_cb_(handle, read_cb, &block->data.vorbis_comment);
2093                 case FLAC__METADATA_TYPE_CUESHEET:
2094                         return read_metadata_block_data_cuesheet_cb_(handle, read_cb, &block->data.cue_sheet);
2095                 case FLAC__METADATA_TYPE_PICTURE:
2096                         return read_metadata_block_data_picture_cb_(handle, read_cb, &block->data.picture);
2097                 default:
2098                         return read_metadata_block_data_unknown_cb_(handle, read_cb, &block->data.unknown, block->length);
2099         }
2100 }
2101
2102 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_StreamInfo *block)
2103 {
2104         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH], *b;
2105
2106         if(read_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
2107                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2108
2109         b = buffer;
2110
2111         /* we are using hardcoded numbers for simplicity but we should
2112          * probably eventually write a bit-level unpacker and use the
2113          * _STREAMINFO_ constants.
2114          */
2115         block->min_blocksize = unpack_uint32_(b, 2); b += 2;
2116         block->max_blocksize = unpack_uint32_(b, 2); b += 2;
2117         block->min_framesize = unpack_uint32_(b, 3); b += 3;
2118         block->max_framesize = unpack_uint32_(b, 3); b += 3;
2119         block->sample_rate = (unpack_uint32_(b, 2) << 4) | ((unsigned)(b[2] & 0xf0) >> 4);
2120         block->channels = (unsigned)((b[2] & 0x0e) >> 1) + 1;
2121         block->bits_per_sample = ((((unsigned)(b[2] & 0x01)) << 4) | (((unsigned)(b[3] & 0xf0)) >> 4)) + 1;
2122         block->total_samples = (((FLAC__uint64)(b[3] & 0x0f)) << 32) | unpack_uint64_(b+4, 4);
2123         memcpy(block->md5sum, b+8, 16);
2124
2125         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2126 }
2127
2128 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata_Padding *block, unsigned block_length)
2129 {
2130         (void)block; /* nothing to do; we don't care about reading the padding bytes */
2131
2132         if(0 != seek_cb(handle, block_length, SEEK_CUR))
2133                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2134
2135         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2136 }
2137
2138 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Application *block, unsigned block_length)
2139 {
2140         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
2141
2142         if(read_cb(block->id, 1, id_bytes, handle) != id_bytes)
2143                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2144
2145         if(block_length < id_bytes)
2146                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2147
2148         block_length -= id_bytes;
2149
2150         if(block_length == 0) {
2151                 block->data = 0;
2152         }
2153         else {
2154                 if(0 == (block->data = malloc(block_length)))
2155                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2156
2157                 if(read_cb(block->data, 1, block_length, handle) != block_length)
2158                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2159         }
2160
2161         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2162 }
2163
2164 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_SeekTable *block, unsigned block_length)
2165 {
2166         unsigned i;
2167         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
2168
2169         FLAC__ASSERT(block_length % FLAC__STREAM_METADATA_SEEKPOINT_LENGTH == 0);
2170
2171         block->num_points = block_length / FLAC__STREAM_METADATA_SEEKPOINT_LENGTH;
2172
2173         if(block->num_points == 0)
2174                 block->points = 0;
2175         else if(0 == (block->points = safe_malloc_mul_2op_p(block->num_points, /*times*/sizeof(FLAC__StreamMetadata_SeekPoint))))
2176                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2177
2178         for(i = 0; i < block->num_points; i++) {
2179                 if(read_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
2180                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2181                 /* some MAGIC NUMBERs here */
2182                 block->points[i].sample_number = unpack_uint64_(buffer, 8);
2183                 block->points[i].stream_offset = unpack_uint64_(buffer+8, 8);
2184                 block->points[i].frame_samples = unpack_uint32_(buffer+16, 2);
2185         }
2186
2187         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2188 }
2189
2190 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_entry_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment_Entry *entry)
2191 {
2192         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
2193         FLAC__byte buffer[4]; /* magic number is asserted below */
2194
2195         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8 == sizeof(buffer));
2196
2197         if(read_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2198                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2199         entry->length = unpack_uint32_little_endian_(buffer, entry_length_len);
2200
2201         if(0 != entry->entry)
2202                 free(entry->entry);
2203
2204         if(entry->length == 0) {
2205                 entry->entry = 0;
2206         }
2207         else {
2208                 if(0 == (entry->entry = safe_malloc_add_2op_(entry->length, /*+*/1)))
2209                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2210
2211                 if(read_cb(entry->entry, 1, entry->length, handle) != entry->length)
2212                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2213
2214                 entry->entry[entry->length] = '\0';
2215         }
2216
2217         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2218 }
2219
2220 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment *block)
2221 {
2222         unsigned i;
2223         FLAC__Metadata_SimpleIteratorStatus status;
2224         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2225         FLAC__byte buffer[4]; /* magic number is asserted below */
2226
2227         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8 == sizeof(buffer));
2228
2229         if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, &(block->vendor_string))))
2230                 return status;
2231
2232         if(read_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2233                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2234         block->num_comments = unpack_uint32_little_endian_(buffer, num_comments_len);
2235
2236         if(block->num_comments == 0) {
2237                 block->comments = 0;
2238         }
2239         else if(0 == (block->comments = calloc(block->num_comments, sizeof(FLAC__StreamMetadata_VorbisComment_Entry))))
2240                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2241
2242         for(i = 0; i < block->num_comments; i++) {
2243                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, block->comments + i)))
2244                         return status;
2245         }
2246
2247         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2248 }
2249
2250 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet_Track *track)
2251 {
2252         unsigned i, len;
2253         FLAC__byte buffer[32]; /* asserted below that this is big enough */
2254
2255         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2256         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2257         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);
2258
2259         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2260         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2261         if(read_cb(buffer, 1, len, handle) != len)
2262                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2263         track->offset = unpack_uint64_(buffer, len);
2264
2265         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2266         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2267         if(read_cb(buffer, 1, len, handle) != len)
2268                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2269         track->number = (FLAC__byte)unpack_uint32_(buffer, len);
2270
2271         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2272         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2273         if(read_cb(track->isrc, 1, len, handle) != len)
2274                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2275
2276         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);
2277         len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2278         if(read_cb(buffer, 1, len, handle) != len)
2279                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2280         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN == 1);
2281         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN == 1);
2282         track->type = buffer[0] >> 7;
2283         track->pre_emphasis = (buffer[0] >> 6) & 1;
2284
2285         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2286         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2287         if(read_cb(buffer, 1, len, handle) != len)
2288                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2289         track->num_indices = (FLAC__byte)unpack_uint32_(buffer, len);
2290
2291         if(track->num_indices == 0) {
2292                 track->indices = 0;
2293         }
2294         else if(0 == (track->indices = calloc(track->num_indices, sizeof(FLAC__StreamMetadata_CueSheet_Index))))
2295                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2296
2297         for(i = 0; i < track->num_indices; i++) {
2298                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2299                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2300                 if(read_cb(buffer, 1, len, handle) != len)
2301                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2302                 track->indices[i].offset = unpack_uint64_(buffer, len);
2303
2304                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2305                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2306                 if(read_cb(buffer, 1, len, handle) != len)
2307                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2308                 track->indices[i].number = (FLAC__byte)unpack_uint32_(buffer, len);
2309
2310                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2311                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2312                 if(read_cb(buffer, 1, len, handle) != len)
2313                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2314         }
2315
2316         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2317 }
2318
2319 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet *block)
2320 {
2321         unsigned i, len;
2322         FLAC__Metadata_SimpleIteratorStatus status;
2323         FLAC__byte buffer[1024]; /* MSVC needs a constant expression so we put a magic number and assert */
2324
2325         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN)/8 <= sizeof(buffer));
2326         FLAC__ASSERT(sizeof(FLAC__uint64) <= sizeof(buffer));
2327
2328         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2329         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2330         if(read_cb(block->media_catalog_number, 1, len, handle) != len)
2331                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2332
2333         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2334         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2335         if(read_cb(buffer, 1, len, handle) != len)
2336                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2337         block->lead_in = unpack_uint64_(buffer, len);
2338
2339         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2340         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2341         if(read_cb(buffer, 1, len, handle) != len)
2342                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2343         block->is_cd = buffer[0]&0x80? true : false;
2344
2345         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2346         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2347         if(read_cb(buffer, 1, len, handle) != len)
2348                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2349         block->num_tracks = unpack_uint32_(buffer, len);
2350
2351         if(block->num_tracks == 0) {
2352                 block->tracks = 0;
2353         }
2354         else if(0 == (block->tracks = calloc(block->num_tracks, sizeof(FLAC__StreamMetadata_CueSheet_Track))))
2355                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2356
2357         for(i = 0; i < block->num_tracks; i++) {
2358                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_cuesheet_track_cb_(handle, read_cb, block->tracks + i)))
2359                         return status;
2360         }
2361
2362         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2363 }
2364
2365 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_picture_cstring_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__byte **data, FLAC__uint32 *length, FLAC__uint32 length_len)
2366 {
2367         FLAC__byte buffer[sizeof(FLAC__uint32)];
2368
2369         FLAC__ASSERT(0 != data);
2370         FLAC__ASSERT(length_len%8 == 0);
2371
2372         length_len /= 8; /* convert to bytes */
2373
2374         FLAC__ASSERT(sizeof(buffer) >= length_len);
2375
2376         if(read_cb(buffer, 1, length_len, handle) != length_len)
2377                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2378         *length = unpack_uint32_(buffer, length_len);
2379
2380         if(0 != *data)
2381                 free(*data);
2382
2383         if(0 == (*data = safe_malloc_add_2op_(*length, /*+*/1)))
2384                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2385
2386         if(*length > 0) {
2387                 if(read_cb(*data, 1, *length, handle) != *length)
2388                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2389         }
2390
2391         (*data)[*length] = '\0';
2392
2393         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2394 }
2395
2396 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Picture *block)
2397 {
2398         FLAC__Metadata_SimpleIteratorStatus status;
2399         FLAC__byte buffer[4]; /* asserted below that this is big enough */
2400         FLAC__uint32 len;
2401
2402         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8);
2403         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8);
2404         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8);
2405         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8);
2406         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8);
2407
2408         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_TYPE_LEN % 8 == 0);
2409         len = FLAC__STREAM_METADATA_PICTURE_TYPE_LEN / 8;
2410         if(read_cb(buffer, 1, len, handle) != len)
2411                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2412         block->type = (FLAC__StreamMetadata_Picture_Type)unpack_uint32_(buffer, len);
2413
2414         if((status = read_metadata_block_data_picture_cstring_cb_(handle, read_cb, (FLAC__byte**)(&(block->mime_type)), &len, FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN)) != FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK)
2415                 return status;
2416
2417         if((status = read_metadata_block_data_picture_cstring_cb_(handle, read_cb, &(block->description), &len, FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN)) != FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK)
2418                 return status;
2419
2420         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN % 8 == 0);
2421         len = FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN / 8;
2422         if(read_cb(buffer, 1, len, handle) != len)
2423                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2424         block->width = unpack_uint32_(buffer, len);
2425
2426         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN % 8 == 0);
2427         len = FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN / 8;
2428         if(read_cb(buffer, 1, len, handle) != len)
2429                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2430         block->height = unpack_uint32_(buffer, len);
2431
2432         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN % 8 == 0);
2433         len = FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN / 8;
2434         if(read_cb(buffer, 1, len, handle) != len)
2435                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2436         block->depth = unpack_uint32_(buffer, len);
2437
2438         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_COLORS_LEN % 8 == 0);
2439         len = FLAC__STREAM_METADATA_PICTURE_COLORS_LEN / 8;
2440         if(read_cb(buffer, 1, len, handle) != len)
2441                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2442         block->colors = unpack_uint32_(buffer, len);
2443
2444         /* for convenience we use read_metadata_block_data_picture_cstring_cb_() even though it adds an extra terminating NUL we don't use */
2445         if((status = read_metadata_block_data_picture_cstring_cb_(handle, read_cb, &(block->data), &(block->data_length), FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN)) != FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK)
2446                 return status;
2447
2448         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2449 }
2450
2451 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2452 {
2453         if(block_length == 0) {
2454                 block->data = 0;
2455         }
2456         else {
2457                 if(0 == (block->data = malloc(block_length)))
2458                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2459
2460                 if(read_cb(block->data, 1, block_length, handle) != block_length)
2461                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2462         }
2463
2464         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2465 }
2466
2467 FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2468 {
2469         FLAC__ASSERT(0 != file);
2470         FLAC__ASSERT(0 != status);
2471
2472         if(!write_metadata_block_header_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2473                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2474                 return false;
2475         }
2476
2477         return true;
2478 }
2479
2480 FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2481 {
2482         FLAC__ASSERT(0 != file);
2483         FLAC__ASSERT(0 != status);
2484
2485         if (write_metadata_block_data_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2486                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2487                 return true;
2488         }
2489         else {
2490                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2491                 return false;
2492         }
2493 }
2494
2495 FLAC__bool write_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2496 {
2497         FLAC__byte buffer[FLAC__STREAM_METADATA_HEADER_LENGTH];
2498
2499         FLAC__ASSERT(block->length < (1u << FLAC__STREAM_METADATA_LENGTH_LEN));
2500
2501         buffer[0] = (block->is_last? 0x80 : 0) | (FLAC__byte)block->type;
2502         pack_uint32_(block->length, buffer + 1, 3);
2503
2504         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
2505                 return false;
2506
2507         return true;
2508 }
2509
2510 FLAC__bool write_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2511 {
2512         FLAC__ASSERT(0 != block);
2513
2514         switch(block->type) {
2515                 case FLAC__METADATA_TYPE_STREAMINFO:
2516                         return write_metadata_block_data_streaminfo_cb_(handle, write_cb, &block->data.stream_info);
2517                 case FLAC__METADATA_TYPE_PADDING:
2518                         return write_metadata_block_data_padding_cb_(handle, write_cb, &block->data.padding, block->length);
2519                 case FLAC__METADATA_TYPE_APPLICATION:
2520                         return write_metadata_block_data_application_cb_(handle, write_cb, &block->data.application, block->length);
2521                 case FLAC__METADATA_TYPE_SEEKTABLE:
2522                         return write_metadata_block_data_seektable_cb_(handle, write_cb, &block->data.seek_table);
2523                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
2524                         return write_metadata_block_data_vorbis_comment_cb_(handle, write_cb, &block->data.vorbis_comment);
2525                 case FLAC__METADATA_TYPE_CUESHEET:
2526                         return write_metadata_block_data_cuesheet_cb_(handle, write_cb, &block->data.cue_sheet);
2527                 case FLAC__METADATA_TYPE_PICTURE:
2528                         return write_metadata_block_data_picture_cb_(handle, write_cb, &block->data.picture);
2529                 default:
2530                         return write_metadata_block_data_unknown_cb_(handle, write_cb, &block->data.unknown, block->length);
2531         }
2532 }
2533
2534 FLAC__bool write_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_StreamInfo *block)
2535 {
2536         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH];
2537         const unsigned channels1 = block->channels - 1;
2538         const unsigned bps1 = block->bits_per_sample - 1;
2539
2540         /* we are using hardcoded numbers for simplicity but we should
2541          * probably eventually write a bit-level packer and use the
2542          * _STREAMINFO_ constants.
2543          */
2544         pack_uint32_(block->min_blocksize, buffer, 2);
2545         pack_uint32_(block->max_blocksize, buffer+2, 2);
2546         pack_uint32_(block->min_framesize, buffer+4, 3);
2547         pack_uint32_(block->max_framesize, buffer+7, 3);
2548         buffer[10] = (block->sample_rate >> 12) & 0xff;
2549         buffer[11] = (block->sample_rate >> 4) & 0xff;
2550         buffer[12] = ((block->sample_rate & 0x0f) << 4) | (channels1 << 1) | (bps1 >> 4);
2551         buffer[13] = (FLAC__byte)(((bps1 & 0x0f) << 4) | ((block->total_samples >> 32) & 0x0f));
2552         pack_uint32_((FLAC__uint32)block->total_samples, buffer+14, 4);
2553         memcpy(buffer+18, block->md5sum, 16);
2554
2555         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
2556                 return false;
2557
2558         return true;
2559 }
2560
2561 FLAC__bool write_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Padding *block, unsigned block_length)
2562 {
2563         unsigned i, n = block_length;
2564         FLAC__byte buffer[1024];
2565
2566         (void)block;
2567
2568         memset(buffer, 0, 1024);
2569
2570         for(i = 0; i < n/1024; i++)
2571                 if(write_cb(buffer, 1, 1024, handle) != 1024)
2572                         return false;
2573
2574         n %= 1024;
2575
2576         if(write_cb(buffer, 1, n, handle) != n)
2577                 return false;
2578
2579         return true;
2580 }
2581
2582 FLAC__bool write_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Application *block, unsigned block_length)
2583 {
2584         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
2585
2586         if(write_cb(block->id, 1, id_bytes, handle) != id_bytes)
2587                 return false;
2588
2589         block_length -= id_bytes;
2590
2591         if(write_cb(block->data, 1, block_length, handle) != block_length)
2592                 return false;
2593
2594         return true;
2595 }
2596
2597 FLAC__bool write_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_SeekTable *block)
2598 {
2599         unsigned i;
2600         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
2601
2602         for(i = 0; i < block->num_points; i++) {
2603                 /* some MAGIC NUMBERs here */
2604                 pack_uint64_(block->points[i].sample_number, buffer, 8);
2605                 pack_uint64_(block->points[i].stream_offset, buffer+8, 8);
2606                 pack_uint32_(block->points[i].frame_samples, buffer+16, 2);
2607                 if(write_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
2608                         return false;
2609         }
2610
2611         return true;
2612 }
2613
2614 FLAC__bool write_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_VorbisComment *block)
2615 {
2616         unsigned i;
2617         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
2618         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2619         FLAC__byte buffer[4]; /* magic number is asserted below */
2620
2621         FLAC__ASSERT(flac_max(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN, FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN) / 8 == sizeof(buffer));
2622
2623         pack_uint32_little_endian_(block->vendor_string.length, buffer, entry_length_len);
2624         if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2625                 return false;
2626         if(write_cb(block->vendor_string.entry, 1, block->vendor_string.length, handle) != block->vendor_string.length)
2627                 return false;
2628
2629         pack_uint32_little_endian_(block->num_comments, buffer, num_comments_len);
2630         if(write_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2631                 return false;
2632
2633         for(i = 0; i < block->num_comments; i++) {
2634                 pack_uint32_little_endian_(block->comments[i].length, buffer, entry_length_len);
2635                 if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2636                         return false;
2637                 if(write_cb(block->comments[i].entry, 1, block->comments[i].length, handle) != block->comments[i].length)
2638                         return false;
2639         }
2640
2641         return true;
2642 }
2643
2644 FLAC__bool write_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_CueSheet *block)
2645 {
2646         unsigned i, j, len;
2647         FLAC__byte buffer[1024]; /* asserted below that this is big enough */
2648
2649         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2650         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN/8);
2651         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);
2652         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2653
2654         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2655         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2656         if(write_cb(block->media_catalog_number, 1, len, handle) != len)
2657                 return false;
2658
2659         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2660         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2661         pack_uint64_(block->lead_in, buffer, len);
2662         if(write_cb(buffer, 1, len, handle) != len)
2663                 return false;
2664
2665         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2666         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2667         memset(buffer, 0, len);
2668         if(block->is_cd)
2669                 buffer[0] |= 0x80;
2670         if(write_cb(buffer, 1, len, handle) != len)
2671                 return false;
2672
2673         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2674         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2675         pack_uint32_(block->num_tracks, buffer, len);
2676         if(write_cb(buffer, 1, len, handle) != len)
2677                 return false;
2678
2679         for(i = 0; i < block->num_tracks; i++) {
2680                 FLAC__StreamMetadata_CueSheet_Track *track = block->tracks + i;
2681
2682                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2683                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2684                 pack_uint64_(track->offset, buffer, len);
2685                 if(write_cb(buffer, 1, len, handle) != len)
2686                         return false;
2687
2688                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2689                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2690                 pack_uint32_(track->number, buffer, len);
2691                 if(write_cb(buffer, 1, len, handle) != len)
2692                         return false;
2693
2694                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2695                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2696                 if(write_cb(track->isrc, 1, len, handle) != len)
2697                         return false;
2698
2699                 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);
2700                 len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2701                 memset(buffer, 0, len);
2702                 buffer[0] = (track->type << 7) | (track->pre_emphasis << 6);
2703                 if(write_cb(buffer, 1, len, handle) != len)
2704                         return false;
2705
2706                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2707                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2708                 pack_uint32_(track->num_indices, buffer, len);
2709                 if(write_cb(buffer, 1, len, handle) != len)
2710                         return false;
2711
2712                 for(j = 0; j < track->num_indices; j++) {
2713                         FLAC__StreamMetadata_CueSheet_Index *index = track->indices + j;
2714
2715                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2716                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2717                         pack_uint64_(index->offset, buffer, len);
2718                         if(write_cb(buffer, 1, len, handle) != len)
2719                                 return false;
2720
2721                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2722                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2723                         pack_uint32_(index->number, buffer, len);
2724                         if(write_cb(buffer, 1, len, handle) != len)
2725                                 return false;
2726
2727                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2728                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2729                         memset(buffer, 0, len);
2730                         if(write_cb(buffer, 1, len, handle) != len)
2731                                 return false;
2732                 }
2733         }
2734
2735         return true;
2736 }
2737
2738 FLAC__bool write_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Picture *block)
2739 {
2740         unsigned len;
2741         size_t slen;
2742         FLAC__byte buffer[4]; /* magic number is asserted below */
2743
2744         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_TYPE_LEN%8);
2745         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN%8);
2746         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN%8);
2747         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN%8);
2748         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN%8);
2749         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN%8);
2750         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_COLORS_LEN%8);
2751         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN%8);
2752         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8);
2753         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN/8);
2754         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN/8);
2755         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8);
2756         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8);
2757         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8);
2758         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8);
2759         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN/8);
2760
2761         len = FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8;
2762         pack_uint32_(block->type, buffer, len);
2763         if(write_cb(buffer, 1, len, handle) != len)
2764                 return false;
2765
2766         len = FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN/8;
2767         slen = strlen(block->mime_type);
2768         pack_uint32_(slen, buffer, len);
2769         if(write_cb(buffer, 1, len, handle) != len)
2770                 return false;
2771         if(write_cb(block->mime_type, 1, slen, handle) != slen)
2772                 return false;
2773
2774         len = FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN/8;
2775         slen = strlen((const char *)block->description);
2776         pack_uint32_(slen, buffer, len);
2777         if(write_cb(buffer, 1, len, handle) != len)
2778                 return false;
2779         if(write_cb(block->description, 1, slen, handle) != slen)
2780                 return false;
2781
2782         len = FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8;
2783         pack_uint32_(block->width, buffer, len);
2784         if(write_cb(buffer, 1, len, handle) != len)
2785                 return false;
2786
2787         len = FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8;
2788         pack_uint32_(block->height, buffer, len);
2789         if(write_cb(buffer, 1, len, handle) != len)
2790                 return false;
2791
2792         len = FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8;
2793         pack_uint32_(block->depth, buffer, len);
2794         if(write_cb(buffer, 1, len, handle) != len)
2795                 return false;
2796
2797         len = FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8;
2798         pack_uint32_(block->colors, buffer, len);
2799         if(write_cb(buffer, 1, len, handle) != len)
2800                 return false;
2801
2802         len = FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN/8;
2803         pack_uint32_(block->data_length, buffer, len);
2804         if(write_cb(buffer, 1, len, handle) != len)
2805                 return false;
2806         if(write_cb(block->data, 1, block->data_length, handle) != block->data_length)
2807                 return false;
2808
2809         return true;
2810 }
2811
2812 FLAC__bool write_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2813 {
2814         if(write_cb(block->data, 1, block_length, handle) != block_length)
2815                 return false;
2816
2817         return true;
2818 }
2819
2820 FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block)
2821 {
2822         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2823                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2824                 return false;
2825         }
2826
2827         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2828                 return false;
2829
2830         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2831                 return false;
2832
2833         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2834                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2835                 return false;
2836         }
2837
2838         return read_metadata_block_header_(iterator);
2839 }
2840
2841 FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last)
2842 {
2843         FLAC__StreamMetadata *padding;
2844
2845         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2846                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2847                 return false;
2848         }
2849
2850         block->is_last = false;
2851
2852         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2853                 return false;
2854
2855         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2856                 return false;
2857
2858         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING)))
2859                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2860
2861         padding->is_last = padding_is_last;
2862         padding->length = padding_length;
2863
2864         if(!write_metadata_block_header_(iterator->file, &iterator->status, padding)) {
2865                 FLAC__metadata_object_delete(padding);
2866                 return false;
2867         }
2868
2869         if(!write_metadata_block_data_(iterator->file, &iterator->status, padding)) {
2870                 FLAC__metadata_object_delete(padding);
2871                 return false;
2872         }
2873
2874         FLAC__metadata_object_delete(padding);
2875
2876         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2877                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2878                 return false;
2879         }
2880
2881         return read_metadata_block_header_(iterator);
2882 }
2883
2884 FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append)
2885 {
2886         FILE *tempfile = NULL;
2887         char *tempfilename = NULL;
2888         int fixup_is_last_code = 0; /* 0 => no need to change any is_last flags */
2889         FLAC__off_t fixup_is_last_flag_offset = -1;
2890
2891         FLAC__ASSERT(0 != block || append == false);
2892
2893         if(iterator->is_last) {
2894                 if(append) {
2895                         fixup_is_last_code = 1; /* 1 => clear the is_last flag at the following offset */
2896                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2897                 }
2898                 else if(0 == block) {
2899                         simple_iterator_push_(iterator);
2900                         if(!FLAC__metadata_simple_iterator_prev(iterator)) {
2901                                 (void)simple_iterator_pop_(iterator);
2902                                 return false;
2903                         }
2904                         fixup_is_last_code = -1; /* -1 => set the is_last the flag at the following offset */
2905                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2906                         if(!simple_iterator_pop_(iterator))
2907                                 return false;
2908                 }
2909         }
2910
2911         if(!simple_iterator_copy_file_prefix_(iterator, &tempfile, &tempfilename, append))
2912                 return false;
2913
2914         if(0 != block) {
2915                 if(!write_metadata_block_header_(tempfile, &iterator->status, block)) {
2916                         cleanup_tempfile_(&tempfile, &tempfilename);
2917                         return false;
2918                 }
2919
2920                 if(!write_metadata_block_data_(tempfile, &iterator->status, block)) {
2921                         cleanup_tempfile_(&tempfile, &tempfilename);
2922                         return false;
2923                 }
2924         }
2925
2926         if(!simple_iterator_copy_file_postfix_(iterator, &tempfile, &tempfilename, fixup_is_last_code, fixup_is_last_flag_offset, block==0))
2927                 return false;
2928
2929         if(append)
2930                 return FLAC__metadata_simple_iterator_next(iterator);
2931
2932         return true;
2933 }
2934
2935 void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator)
2936 {
2937         FLAC__ASSERT(iterator->depth+1 < SIMPLE_ITERATOR_MAX_PUSH_DEPTH);
2938         iterator->offset[iterator->depth+1] = iterator->offset[iterator->depth];
2939         iterator->depth++;
2940 }
2941
2942 FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator)
2943 {
2944         FLAC__ASSERT(iterator->depth > 0);
2945         iterator->depth--;
2946         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2947                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2948                 return false;
2949         }
2950
2951         return read_metadata_block_header_(iterator);
2952 }
2953
2954 /* return meanings:
2955  * 0: ok
2956  * 1: read error
2957  * 2: seek error
2958  * 3: not a FLAC file
2959  */
2960 unsigned seek_to_first_metadata_block_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb)
2961 {
2962         FLAC__byte buffer[4];
2963         size_t n;
2964         unsigned i;
2965
2966         FLAC__ASSERT(FLAC__STREAM_SYNC_LENGTH == sizeof(buffer));
2967
2968         /* skip any id3v2 tag */
2969         errno = 0;
2970         n = read_cb(buffer, 1, 4, handle);
2971         if(errno)
2972                 return 1;
2973         else if(n != 4)
2974                 return 3;
2975         else if(0 == memcmp(buffer, "ID3", 3)) {
2976                 unsigned tag_length = 0;
2977
2978                 /* skip to the tag length */
2979                 if(seek_cb(handle, 2, SEEK_CUR) < 0)
2980                         return 2;
2981
2982                 /* read the length */
2983                 for(i = 0; i < 4; i++) {
2984                         if(read_cb(buffer, 1, 1, handle) < 1 || buffer[0] & 0x80)
2985                                 return 1;
2986                         tag_length <<= 7;
2987                         tag_length |= (buffer[0] & 0x7f);
2988                 }
2989
2990                 /* skip the rest of the tag */
2991                 if(seek_cb(handle, tag_length, SEEK_CUR) < 0)
2992                         return 2;
2993
2994                 /* read the stream sync code */
2995                 errno = 0;
2996                 n = read_cb(buffer, 1, 4, handle);
2997                 if(errno)
2998                         return 1;
2999                 else if(n != 4)
3000                         return 3;
3001         }
3002
3003         /* check for the fLaC signature */
3004         if(0 == memcmp(FLAC__STREAM_SYNC_STRING, buffer, FLAC__STREAM_SYNC_LENGTH))
3005                 return 0;
3006         else
3007                 return 3;
3008 }
3009
3010 unsigned seek_to_first_metadata_block_(FILE *f)
3011 {
3012         return seek_to_first_metadata_block_cb_((FLAC__IOHandle)f, (FLAC__IOCallback_Read)fread, fseek_wrapper_);
3013 }
3014
3015 FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append)
3016 {
3017         const FLAC__off_t offset_end = append? iterator->offset[iterator->depth] + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (FLAC__off_t)iterator->length : iterator->offset[iterator->depth];
3018
3019         if(0 != fseeko(iterator->file, 0, SEEK_SET)) {
3020                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3021                 return false;
3022         }
3023         if(!open_tempfile_(iterator->filename, iterator->tempfile_path_prefix, tempfile, tempfilename, &iterator->status)) {
3024                 cleanup_tempfile_(tempfile, tempfilename);
3025                 return false;
3026         }
3027         if(!copy_n_bytes_from_file_(iterator->file, *tempfile, offset_end, &iterator->status)) {
3028                 cleanup_tempfile_(tempfile, tempfilename);
3029                 return false;
3030         }
3031
3032         return true;
3033 }
3034
3035 FLAC__bool simple_iterator_copy_file_postfix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, int fixup_is_last_code, FLAC__off_t fixup_is_last_flag_offset, FLAC__bool backup)
3036 {
3037         FLAC__off_t save_offset = iterator->offset[iterator->depth];
3038         FLAC__ASSERT(0 != *tempfile);
3039
3040         if(0 != fseeko(iterator->file, save_offset + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (FLAC__off_t)iterator->length, SEEK_SET)) {
3041                 cleanup_tempfile_(tempfile, tempfilename);
3042                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3043                 return false;
3044         }
3045         if(!copy_remaining_bytes_from_file_(iterator->file, *tempfile, &iterator->status)) {
3046                 cleanup_tempfile_(tempfile, tempfilename);
3047                 return false;
3048         }
3049
3050         if(fixup_is_last_code != 0) {
3051                 /*
3052                  * if code == 1, it means a block was appended to the end so
3053                  *   we have to clear the is_last flag of the previous block
3054                  * if code == -1, it means the last block was deleted so
3055                  *   we have to set the is_last flag of the previous block
3056                  */
3057                 /* MAGIC NUMBERs here; we know the is_last flag is the high bit of the byte at this location */
3058                 FLAC__byte x;
3059                 if(0 != fseeko(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
3060                         cleanup_tempfile_(tempfile, tempfilename);
3061                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3062                         return false;
3063                 }
3064                 if(fread(&x, 1, 1, *tempfile) != 1) {
3065                         cleanup_tempfile_(tempfile, tempfilename);
3066                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3067                         return false;
3068                 }
3069                 if(fixup_is_last_code > 0) {
3070                         FLAC__ASSERT(x & 0x80);
3071                         x &= 0x7f;
3072                 }
3073                 else {
3074                         FLAC__ASSERT(!(x & 0x80));
3075                         x |= 0x80;
3076                 }
3077                 if(0 != fseeko(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
3078                         cleanup_tempfile_(tempfile, tempfilename);
3079                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3080                         return false;
3081                 }
3082                 if(local__fwrite(&x, 1, 1, *tempfile) != 1) {
3083                         cleanup_tempfile_(tempfile, tempfilename);
3084                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3085                         return false;
3086                 }
3087         }
3088
3089         (void)fclose(iterator->file);
3090
3091         if(!transport_tempfile_(iterator->filename, tempfile, tempfilename, &iterator->status))
3092                 return false;
3093
3094         if(iterator->has_stats)
3095                 set_file_stats_(iterator->filename, &iterator->stats);
3096
3097         if(!simple_iterator_prime_input_(iterator, !iterator->is_writable))
3098                 return false;
3099         if(backup) {
3100                 while(iterator->offset[iterator->depth] + (FLAC__off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (FLAC__off_t)iterator->length < save_offset)
3101                         if(!FLAC__metadata_simple_iterator_next(iterator))
3102                                 return false;
3103                 return true;
3104         }
3105         else {
3106                 /* move the iterator to it's original block faster by faking a push, then doing a pop_ */
3107                 FLAC__ASSERT(iterator->depth == 0);
3108                 iterator->offset[0] = save_offset;
3109                 iterator->depth++;
3110                 return simple_iterator_pop_(iterator);
3111         }
3112 }
3113
3114 FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status)
3115 {
3116         FLAC__byte buffer[8192];
3117         size_t n;
3118
3119         FLAC__ASSERT(bytes >= 0);
3120         while(bytes > 0) {
3121                 n = flac_min(sizeof(buffer), (size_t)bytes);
3122                 if(fread(buffer, 1, n, file) != n) {
3123                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3124                         return false;
3125                 }
3126                 if(local__fwrite(buffer, 1, n, tempfile) != n) {
3127                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3128                         return false;
3129                 }
3130                 bytes -= n;
3131         }
3132
3133         return true;
3134 }
3135
3136 FLAC__bool copy_n_bytes_from_file_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOHandle temp_handle, FLAC__IOCallback_Write temp_write_cb, FLAC__off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status)
3137 {
3138         FLAC__byte buffer[8192];
3139         size_t n;
3140
3141         FLAC__ASSERT(bytes >= 0);
3142         while(bytes > 0) {
3143                 n = flac_min(sizeof(buffer), (size_t)bytes);
3144                 if(read_cb(buffer, 1, n, handle) != n) {
3145                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3146                         return false;
3147                 }
3148                 if(temp_write_cb(buffer, 1, n, temp_handle) != n) {
3149                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3150                         return false;
3151                 }
3152                 bytes -= n;
3153         }
3154
3155         return true;
3156 }
3157
3158 FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status)
3159 {
3160         FLAC__byte buffer[8192];
3161         size_t n;
3162
3163         while(!feof(file)) {
3164                 n = fread(buffer, 1, sizeof(buffer), file);
3165                 if(n == 0 && !feof(file)) {
3166                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3167                         return false;
3168                 }
3169                 if(n > 0 && local__fwrite(buffer, 1, n, tempfile) != n) {
3170                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3171                         return false;
3172                 }
3173         }
3174
3175         return true;
3176 }
3177
3178 FLAC__bool copy_remaining_bytes_from_file_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Eof eof_cb, FLAC__IOHandle temp_handle, FLAC__IOCallback_Write temp_write_cb, FLAC__Metadata_SimpleIteratorStatus *status)
3179 {
3180         FLAC__byte buffer[8192];
3181         size_t n;
3182
3183         while(!eof_cb(handle)) {
3184                 n = read_cb(buffer, 1, sizeof(buffer), handle);
3185                 if(n == 0 && !eof_cb(handle)) {
3186                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3187                         return false;
3188                 }
3189                 if(n > 0 && temp_write_cb(buffer, 1, n, temp_handle) != n) {
3190                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3191                         return false;
3192                 }
3193         }
3194
3195         return true;
3196 }
3197
3198 FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
3199 {
3200         static const char *tempfile_suffix = ".metadata_edit";
3201         if(0 == tempfile_path_prefix) {
3202                 size_t dest_len = strlen(filename) + strlen(tempfile_suffix) + 1;
3203                 if(0 == (*tempfilename = safe_malloc_(dest_len))) {
3204                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
3205                         return false;
3206                 }
3207                 safe_strncpy(*tempfilename, filename, dest_len);
3208                 safe_strncat(*tempfilename, tempfile_suffix, dest_len);
3209         }
3210         else {
3211                 const char *p = strrchr(filename, '/');
3212                 size_t dest_len;
3213                 if(0 == p)
3214                         p = filename;
3215                 else
3216                         p++;
3217
3218                 dest_len = strlen(tempfile_path_prefix) + strlen(p) + strlen(tempfile_suffix) + 2;
3219
3220                 if(0 == (*tempfilename = safe_malloc_(dest_len))) {
3221                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
3222                         return false;
3223                 }
3224                 safe_strncpy(*tempfilename, tempfile_path_prefix, dest_len);
3225                 safe_strncat(*tempfilename, "/", dest_len);
3226                 safe_strncat(*tempfilename, p, dest_len);
3227                 safe_strncat(*tempfilename, tempfile_suffix, dest_len);
3228         }
3229
3230         if(0 == (*tempfile = fopen(*tempfilename, "w+b"))) {
3231                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
3232                 return false;
3233         }
3234
3235         return true;
3236 }
3237
3238 FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
3239 {
3240         FLAC__ASSERT(0 != filename);
3241         FLAC__ASSERT(0 != tempfile);
3242         FLAC__ASSERT(0 != *tempfile);
3243         FLAC__ASSERT(0 != tempfilename);
3244         FLAC__ASSERT(0 != *tempfilename);
3245         FLAC__ASSERT(0 != status);
3246
3247         (void)fclose(*tempfile);
3248         *tempfile = 0;
3249
3250 #if defined _MSC_VER || defined __BORLANDC__ || defined __MINGW32__ || defined __EMX__
3251         /* on some flavors of windows, rename() will fail if the destination already exists */
3252         if(unlink(filename) < 0) {
3253                 cleanup_tempfile_(tempfile, tempfilename);
3254                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR;
3255                 return false;
3256         }
3257 #endif
3258
3259         /*@@@ to fully support the tempfile_path_prefix we need to update this piece to actually copy across filesystems instead of just rename(): */
3260         if(0 != rename(*tempfilename, filename)) {
3261                 cleanup_tempfile_(tempfile, tempfilename);
3262                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR;
3263                 return false;
3264         }
3265
3266         cleanup_tempfile_(tempfile, tempfilename);
3267
3268         return true;
3269 }
3270
3271 void cleanup_tempfile_(FILE **tempfile, char **tempfilename)
3272 {
3273         if(0 != *tempfile) {
3274                 (void)fclose(*tempfile);
3275                 *tempfile = 0;
3276         }
3277
3278         if(0 != *tempfilename) {
3279                 (void)unlink(*tempfilename);
3280                 free(*tempfilename);
3281                 *tempfilename = 0;
3282         }
3283 }
3284
3285 FLAC__bool get_file_stats_(const char *filename, struct stat *stats)
3286 {
3287         FLAC__ASSERT(0 != filename);
3288         FLAC__ASSERT(0 != stats);
3289         return (0 == stat(filename, stats));
3290 }
3291
3292 void set_file_stats_(const char *filename, struct stat *stats)
3293 {
3294         struct utimbuf srctime;
3295
3296         FLAC__ASSERT(0 != filename);
3297         FLAC__ASSERT(0 != stats);
3298
3299         srctime.actime = stats->st_atime;
3300         srctime.modtime = stats->st_mtime;
3301         (void)chmod(filename, stats->st_mode);
3302         (void)utime(filename, &srctime);
3303 #if !defined _MSC_VER && !defined __BORLANDC__ && !defined __MINGW32__
3304         FLAC_CHECK_RETURN(chown(filename, stats->st_uid, -1));
3305         FLAC_CHECK_RETURN(chown(filename, -1, stats->st_gid));
3306 #endif
3307 }
3308
3309 int fseek_wrapper_(FLAC__IOHandle handle, FLAC__int64 offset, int whence)
3310 {
3311         return fseeko((FILE*)handle, (FLAC__off_t)offset, whence);
3312 }
3313
3314 FLAC__int64 ftell_wrapper_(FLAC__IOHandle handle)
3315 {
3316         return ftello((FILE*)handle);
3317 }
3318
3319 FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status)
3320 {
3321         switch(status) {
3322                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK:
3323                         return FLAC__METADATA_CHAIN_STATUS_OK;
3324                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT:
3325                         return FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT;
3326                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE:
3327                         return FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
3328                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE:
3329                         return FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE;
3330                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE:
3331                         return FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE;
3332                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA:
3333                         return FLAC__METADATA_CHAIN_STATUS_BAD_METADATA;
3334                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR:
3335                         return FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
3336                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR:
3337                         return FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
3338                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR:
3339                         return FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
3340                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR:
3341                         return FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR;
3342                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR:
3343                         return FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR;
3344                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR:
3345                         return FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
3346                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR:
3347                 default:
3348                         return FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
3349         }
3350 }