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 #if defined _MSC_VER || defined __BORLANDC__ || defined __MINGW32__
  42 #if defined __BORLANDC__
  43 #include <utime.h> /* for utime() */
  44 #else
  45 #include <sys/utime.h> /* for utime() */
  46 #endif
  47 #include <io.h> /* for chmod() */
  48 #include <sys/types.h> /* for off_t */
  49 #if _MSC_VER <= 1600 || defined __BORLANDC__ /* @@@ [2G limit] */
  50 #ifndef fseeko
  51 #define fseeko fseek
  52 #endif
  53 #ifndef ftello
  54 #define ftello ftell
  55 #endif
  56 #endif
  57 #else
  58 #include <sys/types.h> /* some flavors of BSD (like OS X) require this to get time_t */
  59 #include <utime.h> /* for utime() */
  60 #include <unistd.h> /* for chown(), unlink() */
  61 #endif
  62 #include <sys/stat.h> /* for stat(), maybe chmod() */
  63
  64 #include "private/metadata.h"
  65
  66 #include "FLAC/assert.h"
  67 #include "FLAC/stream_decoder.h"
  68 #include "share/alloc.h"
  69
  70 #ifdef max
  71 #undef max
  72 #endif
  73 #define max(a,b) ((a)>(b)?(a):(b))
  74 #ifdef min
  75 #undef min
  76 #endif
  77 #define min(a,b) ((a)<(b)?(a):(b))
  78
  79
  80 /****************************************************************************
  81  *
  82  * Local function declarations
  83  *
  84  ***************************************************************************/
  85
  86 static void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes);
  87 static void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes);
  88 static void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes);
  89 static FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes);
  90 static FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes);
  91 static FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes);
  92
  93 static FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator);
  94 static FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block);
  95 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);
  96 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);
  97 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_StreamInfo *block);
  98 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);
  99 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);
 100 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);
 101 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);
 102 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment *block);
 103 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet_Track *track);
 104 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet *block);
 105 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Picture *block);
 106 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);
 107
 108 static FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block);
 109 static FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block);
 110 static FLAC__bool write_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block);
 111 static FLAC__bool write_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block);
 112 static FLAC__bool write_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_StreamInfo *block);
 113 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);
 114 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);
 115 static FLAC__bool write_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_SeekTable *block);
 116 static FLAC__bool write_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_VorbisComment *block);
 117 static FLAC__bool write_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_CueSheet *block);
 118 static FLAC__bool write_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Picture *block);
 119 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);
 120
 121 static FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block);
 122 static FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last);
 123 static FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append);
 124
 125 static void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator);
 126 static FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator);
 127
 128 static unsigned seek_to_first_metadata_block_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb);
 129 static unsigned seek_to_first_metadata_block_(FILE *f);
 130
 131 static FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append);
 132 static FLAC__bool simple_iterator_copy_file_postfix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, int fixup_is_last_code, off_t fixup_is_last_flag_offset, FLAC__bool backup);
 133
 134 static FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status);
 135 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, off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status);
 136 static FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status);
 137 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);
 138
 139 static FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status);
 140 static FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status);
 141 static void cleanup_tempfile_(FILE **tempfile, char **tempfilename);
 142
 143 static FLAC__bool get_file_stats_(const char *filename, struct stat *stats);
 144 static void set_file_stats_(const char *filename, struct stat *stats);
 145
 146 static int fseek_wrapper_(FLAC__IOHandle handle, FLAC__int64 offset, int whence);
 147 static FLAC__int64 ftell_wrapper_(FLAC__IOHandle handle);
 148
 149 static FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status);
 150
 151
 152 #ifdef FLAC__VALGRIND_TESTING
 153 static size_t local__fwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream)
 154 {
 155         size_t ret = fwrite(ptr, size, nmemb, stream);
 156         if(!ferror(stream))
 157                 fflush(stream);
 158         return ret;
 159 }
 160 #else
 161 #define local__fwrite fwrite
 162 #endif
 163
 164 /****************************************************************************
 165  *
 166  * Level 0 implementation
 167  *
 168  ***************************************************************************/
 169
 170 static FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data);
 171 static void metadata_callback_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data);
 172 static void error_callback_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data);
 173
 174 typedef struct {
 175         FLAC__bool got_error;
 176         FLAC__StreamMetadata *object;
 177 } level0_client_data;
 178
 179 static FLAC__StreamMetadata *get_one_metadata_block_(const char *filename, FLAC__MetadataType type)
 180 {
 181         level0_client_data cd;
 182         FLAC__StreamDecoder *decoder;
 183
 184         FLAC__ASSERT(0 != filename);
 185
 186         cd.got_error = false;
 187         cd.object = 0;
 188
 189         decoder = FLAC__stream_decoder_new();
 190
 191         if(0 == decoder)
 192                 return 0;
 193
 194         FLAC__stream_decoder_set_md5_checking(decoder, false);
 195         FLAC__stream_decoder_set_metadata_ignore_all(decoder);
 196         FLAC__stream_decoder_set_metadata_respond(decoder, type);
 197
 198         if(FLAC__stream_decoder_init_file(decoder, filename, write_callback_, metadata_callback_, error_callback_, &cd) != FLAC__STREAM_DECODER_INIT_STATUS_OK || cd.got_error) {
 199                 (void)FLAC__stream_decoder_finish(decoder);
 200                 FLAC__stream_decoder_delete(decoder);
 201                 return 0;
 202         }
 203
 204         if(!FLAC__stream_decoder_process_until_end_of_metadata(decoder) || cd.got_error) {
 205                 (void)FLAC__stream_decoder_finish(decoder);
 206                 FLAC__stream_decoder_delete(decoder);
 207                 if(0 != cd.object)
 208                         FLAC__metadata_object_delete(cd.object);
 209                 return 0;
 210         }
 211
 212         (void)FLAC__stream_decoder_finish(decoder);
 213         FLAC__stream_decoder_delete(decoder);
 214
 215         return cd.object;
 216 }
 217
 218 FLAC_API FLAC__bool FLAC__metadata_get_streaminfo(const char *filename, FLAC__StreamMetadata *streaminfo)
 219 {
 220         FLAC__StreamMetadata *object;
 221
 222         FLAC__ASSERT(0 != filename);
 223         FLAC__ASSERT(0 != streaminfo);
 224
 225         object = get_one_metadata_block_(filename, FLAC__METADATA_TYPE_STREAMINFO);
 226
 227         if (object) {
 228                 /* can just copy the contents since STREAMINFO has no internal structure */
 229                 *streaminfo = *object;
 230                 FLAC__metadata_object_delete(object);
 231                 return true;
 232         }
 233         else {
 234                 return false;
 235         }
 236 }
 237
 238 FLAC_API FLAC__bool FLAC__metadata_get_tags(const char *filename, FLAC__StreamMetadata **tags)
 239 {
 240         FLAC__ASSERT(0 != filename);
 241         FLAC__ASSERT(0 != tags);
 242
 243         *tags = get_one_metadata_block_(filename, FLAC__METADATA_TYPE_VORBIS_COMMENT);
 244
 245         return 0 != *tags;
 246 }
 247
 248 FLAC_API FLAC__bool FLAC__metadata_get_cuesheet(const char *filename, FLAC__StreamMetadata **cuesheet)
 249 {
 250         FLAC__ASSERT(0 != filename);
 251         FLAC__ASSERT(0 != cuesheet);
 252
 253         *cuesheet = get_one_metadata_block_(filename, FLAC__METADATA_TYPE_CUESHEET);
 254
 255         return 0 != *cuesheet;
 256 }
 257
 258 FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
 259 {
 260         (void)decoder, (void)frame, (void)buffer, (void)client_data;
 261
 262         return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;
 263 }
 264
 265 void metadata_callback_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
 266 {
 267         level0_client_data *cd = (level0_client_data *)client_data;
 268         (void)decoder;
 269
 270         /*
 271          * we assume we only get here when the one metadata block we were
 272          * looking for was passed to us
 273          */
 274         if(!cd->got_error && 0 == cd->object) {
 275                 if(0 == (cd->object = FLAC__metadata_object_clone(metadata)))
 276                         cd->got_error = true;
 277         }
 278 }
 279
 280 void error_callback_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
 281 {
 282         level0_client_data *cd = (level0_client_data *)client_data;
 283         (void)decoder;
 284
 285         if(status != FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC)
 286                 cd->got_error = true;
 287 }
 288
 289 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)
 290 {
 291         FLAC__Metadata_SimpleIterator *it;
 292         FLAC__uint64 max_area_seen = 0;
 293         FLAC__uint64 max_depth_seen = 0;
 294
 295         FLAC__ASSERT(0 != filename);
 296         FLAC__ASSERT(0 != picture);
 297
 298         *picture = 0;
 299
 300         it = FLAC__metadata_simple_iterator_new();
 301         if(0 == it)
 302                 return false;
 303         if(!FLAC__metadata_simple_iterator_init(it, filename, /*read_only=*/true, /*preserve_file_stats=*/true)) {
 304                 FLAC__metadata_simple_iterator_delete(it);
 305                 return false;
 306         }
 307         do {
 308                 if(FLAC__metadata_simple_iterator_get_block_type(it) == FLAC__METADATA_TYPE_PICTURE) {
 309                         FLAC__StreamMetadata *obj = FLAC__metadata_simple_iterator_get_block(it);
 310                         FLAC__uint64 area = (FLAC__uint64)obj->data.picture.width * (FLAC__uint64)obj->data.picture.height;
 311                         /* check constraints */
 312                         if(
 313                                 (type == (FLAC__StreamMetadata_Picture_Type)(-1) || type == obj->data.picture.type) &&
 314                                 (mime_type == 0 || !strcmp(mime_type, obj->data.picture.mime_type)) &&
 315                                 (description == 0 || !strcmp((const char *)description, (const char *)obj->data.picture.description)) &&
 316                                 obj->data.picture.width <= max_width &&
 317                                 obj->data.picture.height <= max_height &&
 318                                 obj->data.picture.depth <= max_depth &&
 319                                 obj->data.picture.colors <= max_colors &&
 320                                 (area > max_area_seen || (area == max_area_seen && obj->data.picture.depth > max_depth_seen))
 321                         ) {
 322                                 if(*picture)
 323                                         FLAC__metadata_object_delete(*picture);
 324                                 *picture = obj;
 325                                 max_area_seen = area;
 326                                 max_depth_seen = obj->data.picture.depth;
 327                         }
 328                         else {
 329                                 FLAC__metadata_object_delete(obj);
 330                         }
 331                 }
 332         } while(FLAC__metadata_simple_iterator_next(it));
 333
 334         FLAC__metadata_simple_iterator_delete(it);
 335
 336         return (0 != *picture);
 337 }
 338
 339
 340 /****************************************************************************
 341  *
 342  * Level 1 implementation
 343  *
 344  ***************************************************************************/
 345
 346 #define SIMPLE_ITERATOR_MAX_PUSH_DEPTH (1+4)
 347 /* 1 for initial offset, +4 for our own personal use */
 348
 349 struct FLAC__Metadata_SimpleIterator {
 350         FILE *file;
 351         char *filename, *tempfile_path_prefix;
 352         struct stat stats;
 353         FLAC__bool has_stats;
 354         FLAC__bool is_writable;
 355         FLAC__Metadata_SimpleIteratorStatus status;
 356         off_t offset[SIMPLE_ITERATOR_MAX_PUSH_DEPTH];
 357         off_t first_offset; /* this is the offset to the STREAMINFO block */
 358         unsigned depth;
 359         /* this is the metadata block header of the current block we are pointing to: */
 360         FLAC__bool is_last;
 361         FLAC__MetadataType type;
 362         unsigned length;
 363 };
 364
 365 FLAC_API const char * const FLAC__Metadata_SimpleIteratorStatusString[] = {
 366         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK",
 367         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT",
 368         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE",
 369         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE",
 370         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE",
 371         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA",
 372         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR",
 373         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR",
 374         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR",
 375         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR",
 376         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR",
 377         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR",
 378         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR"
 379 };
 380
 381
 382 FLAC_API FLAC__Metadata_SimpleIterator *FLAC__metadata_simple_iterator_new(void)
 383 {
 384         FLAC__Metadata_SimpleIterator *iterator = (FLAC__Metadata_SimpleIterator*)calloc(1, sizeof(FLAC__Metadata_SimpleIterator));
 385
 386         if(0 != iterator) {
 387                 iterator->file = 0;
 388                 iterator->filename = 0;
 389                 iterator->tempfile_path_prefix = 0;
 390                 iterator->has_stats = false;
 391                 iterator->is_writable = false;
 392                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
 393                 iterator->first_offset = iterator->offset[0] = -1;
 394                 iterator->depth = 0;
 395         }
 396
 397         return iterator;
 398 }
 399
 400 static void simple_iterator_free_guts_(FLAC__Metadata_SimpleIterator *iterator)
 401 {
 402         FLAC__ASSERT(0 != iterator);
 403
 404         if(0 != iterator->file) {
 405                 fclose(iterator->file);
 406                 iterator->file = 0;
 407                 if(iterator->has_stats)
 408                         set_file_stats_(iterator->filename, &iterator->stats);
 409         }
 410         if(0 != iterator->filename) {
 411                 free(iterator->filename);
 412                 iterator->filename = 0;
 413         }
 414         if(0 != iterator->tempfile_path_prefix) {
 415                 free(iterator->tempfile_path_prefix);
 416                 iterator->tempfile_path_prefix = 0;
 417         }
 418 }
 419
 420 FLAC_API void FLAC__metadata_simple_iterator_delete(FLAC__Metadata_SimpleIterator *iterator)
 421 {
 422         FLAC__ASSERT(0 != iterator);
 423
 424         simple_iterator_free_guts_(iterator);
 425         free(iterator);
 426 }
 427
 428 FLAC_API FLAC__Metadata_SimpleIteratorStatus FLAC__metadata_simple_iterator_status(FLAC__Metadata_SimpleIterator *iterator)
 429 {
 430         FLAC__Metadata_SimpleIteratorStatus status;
 431
 432         FLAC__ASSERT(0 != iterator);
 433
 434         status = iterator->status;
 435         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
 436         return status;
 437 }
 438
 439 static FLAC__bool simple_iterator_prime_input_(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool read_only)
 440 {
 441         unsigned ret;
 442
 443         FLAC__ASSERT(0 != iterator);
 444
 445         if(read_only || 0 == (iterator->file = fopen(iterator->filename, "r+b"))) {
 446                 iterator->is_writable = false;
 447                 if(read_only || errno == EACCES) {
 448                         if(0 == (iterator->file = fopen(iterator->filename, "rb"))) {
 449                                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
 450                                 return false;
 451                         }
 452                 }
 453                 else {
 454                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
 455                         return false;
 456                 }
 457         }
 458         else {
 459                 iterator->is_writable = true;
 460         }
 461
 462         ret = seek_to_first_metadata_block_(iterator->file);
 463         switch(ret) {
 464                 case 0:
 465                         iterator->depth = 0;
 466                         iterator->first_offset = iterator->offset[iterator->depth] = ftello(iterator->file);
 467                         return read_metadata_block_header_(iterator);
 468                 case 1:
 469                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
 470                         return false;
 471                 case 2:
 472                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 473                         return false;
 474                 case 3:
 475                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE;
 476                         return false;
 477                 default:
 478                         FLAC__ASSERT(0);
 479                         return false;
 480         }
 481 }
 482
 483 #if 0
 484 @@@ If we decide to finish implementing this, put this comment back in metadata.h
 485 /*
 486  * The 'tempfile_path_prefix' allows you to specify a directory where
 487  * tempfiles should go.  Remember that if your metadata edits cause the
 488  * FLAC file to grow, the entire file will have to be rewritten.  If
 489  * 'tempfile_path_prefix' is NULL, the temp file will be written in the
 490  * same directory as the original FLAC file.  This makes replacing the
 491  * original with the tempfile fast but requires extra space in the same
 492  * partition for the tempfile.  If space is a problem, you can pass a
 493  * directory name belonging to a different partition in
 494  * 'tempfile_path_prefix'.  Note that you should use the forward slash
 495  * '/' as the directory separator.  A trailing slash is not needed; it
 496  * will be added automatically.
 497  */
 498 FLAC__bool FLAC__metadata_simple_iterator_init(FLAC__Metadata_SimpleIterator *iterator, const char *filename, FLAC__bool preserve_file_stats, const char *tempfile_path_prefix);
 499 #endif
 500
 501 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)
 502 {
 503         const char *tempfile_path_prefix = 0; /*@@@ search for comments near 'rename(...)' for what it will take to finish implementing this */
 504
 505         FLAC__ASSERT(0 != iterator);
 506         FLAC__ASSERT(0 != filename);
 507
 508         simple_iterator_free_guts_(iterator);
 509
 510         if(!read_only && preserve_file_stats)
 511                 iterator->has_stats = get_file_stats_(filename, &iterator->stats);
 512
 513         if(0 == (iterator->filename = strdup(filename))) {
 514                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 515                 return false;
 516         }
 517         if(0 != tempfile_path_prefix && 0 == (iterator->tempfile_path_prefix = strdup(tempfile_path_prefix))) {
 518                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 519                 return false;
 520         }
 521
 522         return simple_iterator_prime_input_(iterator, read_only);
 523 }
 524
 525 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_is_writable(const FLAC__Metadata_SimpleIterator *iterator)
 526 {
 527         FLAC__ASSERT(0 != iterator);
 528         FLAC__ASSERT(0 != iterator->file);
 529
 530         return iterator->is_writable;
 531 }
 532
 533 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_next(FLAC__Metadata_SimpleIterator *iterator)
 534 {
 535         FLAC__ASSERT(0 != iterator);
 536         FLAC__ASSERT(0 != iterator->file);
 537
 538         if(iterator->is_last)
 539                 return false;
 540
 541         if(0 != fseeko(iterator->file, iterator->length, SEEK_CUR)) {
 542                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 543                 return false;
 544         }
 545
 546         iterator->offset[iterator->depth] = ftello(iterator->file);
 547
 548         return read_metadata_block_header_(iterator);
 549 }
 550
 551 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_prev(FLAC__Metadata_SimpleIterator *iterator)
 552 {
 553         off_t this_offset;
 554
 555         FLAC__ASSERT(0 != iterator);
 556         FLAC__ASSERT(0 != iterator->file);
 557
 558         if(iterator->offset[iterator->depth] == iterator->first_offset)
 559                 return false;
 560
 561         if(0 != fseeko(iterator->file, iterator->first_offset, SEEK_SET)) {
 562                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 563                 return false;
 564         }
 565         this_offset = iterator->first_offset;
 566         if(!read_metadata_block_header_(iterator))
 567                 return false;
 568
 569         /* we ignore any error from ftello() and catch it in fseeko() */
 570         while(ftello(iterator->file) + (off_t)iterator->length < iterator->offset[iterator->depth]) {
 571                 if(0 != fseeko(iterator->file, iterator->length, SEEK_CUR)) {
 572                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 573                         return false;
 574                 }
 575                 this_offset = ftello(iterator->file);
 576                 if(!read_metadata_block_header_(iterator))
 577                         return false;
 578         }
 579
 580         iterator->offset[iterator->depth] = this_offset;
 581
 582         return true;
 583 }
 584
 585 /*@@@@add to tests*/
 586 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_is_last(const FLAC__Metadata_SimpleIterator *iterator)
 587 {
 588         FLAC__ASSERT(0 != iterator);
 589         FLAC__ASSERT(0 != iterator->file);
 590
 591         return iterator->is_last;
 592 }
 593
 594 /*@@@@add to tests*/
 595 FLAC_API off_t FLAC__metadata_simple_iterator_get_block_offset(const FLAC__Metadata_SimpleIterator *iterator)
 596 {
 597         FLAC__ASSERT(0 != iterator);
 598         FLAC__ASSERT(0 != iterator->file);
 599
 600         return iterator->offset[iterator->depth];
 601 }
 602
 603 FLAC_API FLAC__MetadataType FLAC__metadata_simple_iterator_get_block_type(const FLAC__Metadata_SimpleIterator *iterator)
 604 {
 605         FLAC__ASSERT(0 != iterator);
 606         FLAC__ASSERT(0 != iterator->file);
 607
 608         return iterator->type;
 609 }
 610
 611 /*@@@@add to tests*/
 612 FLAC_API unsigned FLAC__metadata_simple_iterator_get_block_length(const FLAC__Metadata_SimpleIterator *iterator)
 613 {
 614         FLAC__ASSERT(0 != iterator);
 615         FLAC__ASSERT(0 != iterator->file);
 616
 617         return iterator->length;
 618 }
 619
 620 /*@@@@add to tests*/
 621 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_get_application_id(FLAC__Metadata_SimpleIterator *iterator, FLAC__byte *id)
 622 {
 623         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
 624
 625         FLAC__ASSERT(0 != iterator);
 626         FLAC__ASSERT(0 != iterator->file);
 627         FLAC__ASSERT(0 != id);
 628
 629         if(iterator->type != FLAC__METADATA_TYPE_APPLICATION) {
 630                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 631                 return false;
 632         }
 633
 634         if(fread(id, 1, id_bytes, iterator->file) != id_bytes) {
 635                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
 636                 return false;
 637         }
 638
 639         /* back up */
 640         if(0 != fseeko(iterator->file, -((int)id_bytes), SEEK_CUR)) {
 641                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 642                 return false;
 643         }
 644
 645         return true;
 646 }
 647
 648 FLAC_API FLAC__StreamMetadata *FLAC__metadata_simple_iterator_get_block(FLAC__Metadata_SimpleIterator *iterator)
 649 {
 650         FLAC__StreamMetadata *block = FLAC__metadata_object_new(iterator->type);
 651
 652         FLAC__ASSERT(0 != iterator);
 653         FLAC__ASSERT(0 != iterator->file);
 654
 655         if(0 != block) {
 656                 block->is_last = iterator->is_last;
 657                 block->length = iterator->length;
 658
 659                 if(!read_metadata_block_data_(iterator, block)) {
 660                         FLAC__metadata_object_delete(block);
 661                         return 0;
 662                 }
 663
 664                 /* back up to the beginning of the block data to stay consistent */
 665                 if(0 != fseeko(iterator->file, iterator->offset[iterator->depth] + FLAC__STREAM_METADATA_HEADER_LENGTH, SEEK_SET)) {
 666                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 667                         FLAC__metadata_object_delete(block);
 668                         return 0;
 669                 }
 670         }
 671         else
 672                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 673
 674         return block;
 675 }
 676
 677 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_set_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding)
 678 {
 679         FLAC__ASSERT_DECLARATION(off_t debug_target_offset = iterator->offset[iterator->depth];)
 680         FLAC__bool ret;
 681
 682         FLAC__ASSERT(0 != iterator);
 683         FLAC__ASSERT(0 != iterator->file);
 684         FLAC__ASSERT(0 != block);
 685
 686         if(!iterator->is_writable) {
 687                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE;
 688                 return false;
 689         }
 690
 691         if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO || block->type == FLAC__METADATA_TYPE_STREAMINFO) {
 692                 if(iterator->type != block->type) {
 693                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 694                         return false;
 695                 }
 696         }
 697
 698         block->is_last = iterator->is_last;
 699
 700         if(iterator->length == block->length)
 701                 return write_metadata_block_stationary_(iterator, block);
 702         else if(iterator->length > block->length) {
 703                 if(use_padding && iterator->length >= FLAC__STREAM_METADATA_HEADER_LENGTH + block->length) {
 704                         ret = write_metadata_block_stationary_with_padding_(iterator, block, iterator->length - FLAC__STREAM_METADATA_HEADER_LENGTH - block->length, block->is_last);
 705                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 706                         FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 707                         return ret;
 708                 }
 709                 else {
 710                         ret = rewrite_whole_file_(iterator, block, /*append=*/false);
 711                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 712                         FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 713                         return ret;
 714                 }
 715         }
 716         else /* iterator->length < block->length */ {
 717                 unsigned padding_leftover = 0;
 718                 FLAC__bool padding_is_last = false;
 719                 if(use_padding) {
 720                         /* first see if we can even use padding */
 721                         if(iterator->is_last) {
 722                                 use_padding = false;
 723                         }
 724                         else {
 725                                 const unsigned extra_padding_bytes_required = block->length - iterator->length;
 726                                 simple_iterator_push_(iterator);
 727                                 if(!FLAC__metadata_simple_iterator_next(iterator)) {
 728                                         (void)simple_iterator_pop_(iterator);
 729                                         return false;
 730                                 }
 731                                 if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
 732                                         use_padding = false;
 733                                 }
 734                                 else {
 735                                         if(FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length == extra_padding_bytes_required) {
 736                                                 padding_leftover = 0;
 737                                                 block->is_last = iterator->is_last;
 738                                         }
 739                                         else if(iterator->length < extra_padding_bytes_required)
 740                                                 use_padding = false;
 741                                         else {
 742                                                 padding_leftover = FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length - extra_padding_bytes_required;
 743                                                 padding_is_last = iterator->is_last;
 744                                                 block->is_last = false;
 745                                         }
 746                                 }
 747                                 if(!simple_iterator_pop_(iterator))
 748                                         return false;
 749                         }
 750                 }
 751                 if(use_padding) {
 752                         if(padding_leftover == 0) {
 753                                 ret = write_metadata_block_stationary_(iterator, block);
 754                                 FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 755                                 FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 756                                 return ret;
 757                         }
 758                         else {
 759                                 FLAC__ASSERT(padding_leftover >= FLAC__STREAM_METADATA_HEADER_LENGTH);
 760                                 ret = write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover - FLAC__STREAM_METADATA_HEADER_LENGTH, padding_is_last);
 761                                 FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 762                                 FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 763                                 return ret;
 764                         }
 765                 }
 766                 else {
 767                         ret = rewrite_whole_file_(iterator, block, /*append=*/false);
 768                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 769                         FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 770                         return ret;
 771                 }
 772         }
 773 }
 774
 775 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_insert_block_after(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding)
 776 {
 777         unsigned padding_leftover = 0;
 778         FLAC__bool padding_is_last = false;
 779
 780         FLAC__ASSERT_DECLARATION(off_t debug_target_offset = iterator->offset[iterator->depth] + FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length;)
 781         FLAC__bool ret;
 782
 783         FLAC__ASSERT(0 != iterator);
 784         FLAC__ASSERT(0 != iterator->file);
 785         FLAC__ASSERT(0 != block);
 786
 787         if(!iterator->is_writable)
 788                 return false;
 789
 790         if(block->type == FLAC__METADATA_TYPE_STREAMINFO) {
 791                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 792                 return false;
 793         }
 794
 795         block->is_last = iterator->is_last;
 796
 797         if(use_padding) {
 798                 /* first see if we can even use padding */
 799                 if(iterator->is_last) {
 800                         use_padding = false;
 801                 }
 802                 else {
 803                         simple_iterator_push_(iterator);
 804                         if(!FLAC__metadata_simple_iterator_next(iterator)) {
 805                                 (void)simple_iterator_pop_(iterator);
 806                                 return false;
 807                         }
 808                         if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
 809                                 use_padding = false;
 810                         }
 811                         else {
 812                                 if(iterator->length == block->length) {
 813                                         padding_leftover = 0;
 814                                         block->is_last = iterator->is_last;
 815                                 }
 816                                 else if(iterator->length < FLAC__STREAM_METADATA_HEADER_LENGTH + block->length)
 817                                         use_padding = false;
 818                                 else {
 819                                         padding_leftover = iterator->length - block->length;
 820                                         padding_is_last = iterator->is_last;
 821                                         block->is_last = false;
 822                                 }
 823                         }
 824                         if(!simple_iterator_pop_(iterator))
 825                                 return false;
 826                 }
 827         }
 828         if(use_padding) {
 829                 /* move to the next block, which is suitable padding */
 830                 if(!FLAC__metadata_simple_iterator_next(iterator))
 831                         return false;
 832                 if(padding_leftover == 0) {
 833                         ret = write_metadata_block_stationary_(iterator, block);
 834                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 835                         FLAC__ASSERT(ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 836                         return ret;
 837                 }
 838                 else {
 839                         FLAC__ASSERT(padding_leftover >= FLAC__STREAM_METADATA_HEADER_LENGTH);
 840                         ret = write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover - FLAC__STREAM_METADATA_HEADER_LENGTH, padding_is_last);
 841                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 842                         FLAC__ASSERT(ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 843                         return ret;
 844                 }
 845         }
 846         else {
 847                 ret = rewrite_whole_file_(iterator, block, /*append=*/true);
 848                 FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 849                 FLAC__ASSERT(ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 850                 return ret;
 851         }
 852 }
 853
 854 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_delete_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool use_padding)
 855 {
 856         FLAC__ASSERT_DECLARATION(off_t debug_target_offset = iterator->offset[iterator->depth];)
 857         FLAC__bool ret;
 858
 859         if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO) {
 860                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 861                 return false;
 862         }
 863
 864         if(use_padding) {
 865                 FLAC__StreamMetadata *padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING);
 866                 if(0 == padding) {
 867                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 868                         return false;
 869                 }
 870                 padding->length = iterator->length;
 871                 if(!FLAC__metadata_simple_iterator_set_block(iterator, padding, false)) {
 872                         FLAC__metadata_object_delete(padding);
 873                         return false;
 874                 }
 875                 FLAC__metadata_object_delete(padding);
 876                 if(!FLAC__metadata_simple_iterator_prev(iterator))
 877                         return false;
 878                 FLAC__ASSERT(iterator->offset[iterator->depth] + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length == debug_target_offset);
 879                 FLAC__ASSERT(ftello(iterator->file) + (off_t)iterator->length == debug_target_offset);
 880                 return true;
 881         }
 882         else {
 883                 ret = rewrite_whole_file_(iterator, 0, /*append=*/false);
 884                 FLAC__ASSERT(iterator->offset[iterator->depth] + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length == debug_target_offset);
 885                 FLAC__ASSERT(ftello(iterator->file) + (off_t)iterator->length == debug_target_offset);
 886                 return ret;
 887         }
 888 }
 889
 890
 891
 892 /****************************************************************************
 893  *
 894  * Level 2 implementation
 895  *
 896  ***************************************************************************/
 897
 898
 899 typedef struct FLAC__Metadata_Node {
 900         FLAC__StreamMetadata *data;
 901         struct FLAC__Metadata_Node *prev, *next;
 902 } FLAC__Metadata_Node;
 903
 904 struct FLAC__Metadata_Chain {
 905         char *filename; /* will be NULL if using callbacks */
 906         FLAC__bool is_ogg;
 907         FLAC__Metadata_Node *head;
 908         FLAC__Metadata_Node *tail;
 909         unsigned nodes;
 910         FLAC__Metadata_ChainStatus status;
 911         off_t first_offset, last_offset;
 912         /*
 913          * This is the length of the chain initially read from the FLAC file.
 914          * it is used to compare against the current length to decide whether
 915          * or not the whole file has to be rewritten.
 916          */
 917         off_t initial_length;
 918         /* @@@ hacky, these are currently only needed by ogg reader */
 919         FLAC__IOHandle handle;
 920         FLAC__IOCallback_Read read_cb;
 921 };
 922
 923 struct FLAC__Metadata_Iterator {
 924         FLAC__Metadata_Chain *chain;
 925         FLAC__Metadata_Node *current;
 926 };
 927
 928 FLAC_API const char * const FLAC__Metadata_ChainStatusString[] = {
 929         "FLAC__METADATA_CHAIN_STATUS_OK",
 930         "FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT",
 931         "FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE",
 932         "FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE",
 933         "FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE",
 934         "FLAC__METADATA_CHAIN_STATUS_BAD_METADATA",
 935         "FLAC__METADATA_CHAIN_STATUS_READ_ERROR",
 936         "FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR",
 937         "FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR",
 938         "FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR",
 939         "FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR",
 940         "FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR",
 941         "FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR",
 942         "FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS",
 943         "FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH",
 944         "FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL"
 945 };
 946
 947
 948 static FLAC__Metadata_Node *node_new_(void)
 949 {
 950         return (FLAC__Metadata_Node*)calloc(1, sizeof(FLAC__Metadata_Node));
 951 }
 952
 953 static void node_delete_(FLAC__Metadata_Node *node)
 954 {
 955         FLAC__ASSERT(0 != node);
 956         if(0 != node->data)
 957                 FLAC__metadata_object_delete(node->data);
 958         free(node);
 959 }
 960
 961 static void chain_init_(FLAC__Metadata_Chain *chain)
 962 {
 963         FLAC__ASSERT(0 != chain);
 964
 965         chain->filename = 0;
 966         chain->is_ogg = false;
 967         chain->head = chain->tail = 0;
 968         chain->nodes = 0;
 969         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
 970         chain->initial_length = 0;
 971         chain->read_cb = 0;
 972 }
 973
 974 static void chain_clear_(FLAC__Metadata_Chain *chain)
 975 {
 976         FLAC__Metadata_Node *node, *next;
 977
 978         FLAC__ASSERT(0 != chain);
 979
 980         for(node = chain->head; node; ) {
 981                 next = node->next;
 982                 node_delete_(node);
 983                 node = next;
 984         }
 985
 986         if(0 != chain->filename)
 987                 free(chain->filename);
 988
 989         chain_init_(chain);
 990 }
 991
 992 static void chain_append_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 993 {
 994         FLAC__ASSERT(0 != chain);
 995         FLAC__ASSERT(0 != node);
 996         FLAC__ASSERT(0 != node->data);
 997
 998         node->next = node->prev = 0;
 999         node->data->is_last = true;
1000         if(0 != chain->tail)
1001                 chain->tail->data->is_last = false;
1002
1003         if(0 == chain->head)
1004                 chain->head = node;
1005         else {
1006                 FLAC__ASSERT(0 != chain->tail);
1007                 chain->tail->next = node;
1008                 node->prev = chain->tail;
1009         }
1010         chain->tail = node;
1011         chain->nodes++;
1012 }
1013
1014 static void chain_remove_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
1015 {
1016         FLAC__ASSERT(0 != chain);
1017         FLAC__ASSERT(0 != node);
1018
1019         if(node == chain->head)
1020                 chain->head = node->next;
1021         else
1022                 node->prev->next = node->next;
1023
1024         if(node == chain->tail)
1025                 chain->tail = node->prev;
1026         else
1027                 node->next->prev = node->prev;
1028
1029         if(0 != chain->tail)
1030                 chain->tail->data->is_last = true;
1031
1032         chain->nodes--;
1033 }
1034
1035 static void chain_delete_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
1036 {
1037         chain_remove_node_(chain, node);
1038         node_delete_(node);
1039 }
1040
1041 static off_t chain_calculate_length_(FLAC__Metadata_Chain *chain)
1042 {
1043         const FLAC__Metadata_Node *node;
1044         off_t length = 0;
1045         for(node = chain->head; node; node = node->next)
1046                 length += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1047         return length;
1048 }
1049
1050 static void iterator_insert_node_(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Node *node)
1051 {
1052         FLAC__ASSERT(0 != node);
1053         FLAC__ASSERT(0 != node->data);
1054         FLAC__ASSERT(0 != iterator);
1055         FLAC__ASSERT(0 != iterator->current);
1056         FLAC__ASSERT(0 != iterator->chain);
1057         FLAC__ASSERT(0 != iterator->chain->head);
1058         FLAC__ASSERT(0 != iterator->chain->tail);
1059
1060         node->data->is_last = false;
1061
1062         node->prev = iterator->current->prev;
1063         node->next = iterator->current;
1064
1065         if(0 == node->prev)
1066                 iterator->chain->head = node;
1067         else
1068                 node->prev->next = node;
1069
1070         iterator->current->prev = node;
1071
1072         iterator->chain->nodes++;
1073 }
1074
1075 static void iterator_insert_node_after_(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Node *node)
1076 {
1077         FLAC__ASSERT(0 != node);
1078         FLAC__ASSERT(0 != node->data);
1079         FLAC__ASSERT(0 != iterator);
1080         FLAC__ASSERT(0 != iterator->current);
1081         FLAC__ASSERT(0 != iterator->chain);
1082         FLAC__ASSERT(0 != iterator->chain->head);
1083         FLAC__ASSERT(0 != iterator->chain->tail);
1084
1085         iterator->current->data->is_last = false;
1086
1087         node->prev = iterator->current;
1088         node->next = iterator->current->next;
1089
1090         if(0 == node->next)
1091                 iterator->chain->tail = node;
1092         else
1093                 node->next->prev = node;
1094
1095         node->prev->next = node;
1096
1097         iterator->chain->tail->data->is_last = true;
1098
1099         iterator->chain->nodes++;
1100 }
1101
1102 /* return true iff node and node->next are both padding */
1103 static FLAC__bool chain_merge_adjacent_padding_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
1104 {
1105         if(node->data->type == FLAC__METADATA_TYPE_PADDING && 0 != node->next && node->next->data->type == FLAC__METADATA_TYPE_PADDING) {
1106                 const unsigned growth = FLAC__STREAM_METADATA_HEADER_LENGTH + node->next->data->length;
1107                 node->data->length += growth;
1108
1109                 chain_delete_node_(chain, node->next);
1110                 return true;
1111         }
1112         else
1113                 return false;
1114 }
1115
1116 /* Returns the new length of the chain, or 0 if there was an error. */
1117 /* WATCHOUT: This can get called multiple times before a write, so
1118  * it should still work when this happens.
1119  */
1120 /* WATCHOUT: Make sure to also update the logic in
1121  * FLAC__metadata_chain_check_if_tempfile_needed() if the logic here changes.
1122  */
1123 static off_t chain_prepare_for_write_(FLAC__Metadata_Chain *chain, FLAC__bool use_padding)
1124 {
1125         off_t current_length = chain_calculate_length_(chain);
1126
1127         if(use_padding) {
1128                 /* if the metadata shrank and the last block is padding, we just extend the last padding block */
1129                 if(current_length < chain->initial_length && chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1130                         const off_t delta = chain->initial_length - current_length;
1131                         chain->tail->data->length += delta;
1132                         current_length += delta;
1133                         FLAC__ASSERT(current_length == chain->initial_length);
1134                 }
1135                 /* if the metadata shrank more than 4 bytes then there's room to add another padding block */
1136                 else if(current_length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH <= chain->initial_length) {
1137                         FLAC__StreamMetadata *padding;
1138                         FLAC__Metadata_Node *node;
1139                         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING))) {
1140                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1141                                 return 0;
1142                         }
1143                         padding->length = chain->initial_length - (FLAC__STREAM_METADATA_HEADER_LENGTH + current_length);
1144                         if(0 == (node = node_new_())) {
1145                                 FLAC__metadata_object_delete(padding);
1146                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1147                                 return 0;
1148                         }
1149                         node->data = padding;
1150                         chain_append_node_(chain, node);
1151                         current_length = chain_calculate_length_(chain);
1152                         FLAC__ASSERT(current_length == chain->initial_length);
1153                 }
1154                 /* 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 */
1155                 else if(current_length > chain->initial_length) {
1156                         const off_t delta = current_length - chain->initial_length;
1157                         if(chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1158                                 /* if the delta is exactly the size of the last padding block, remove the padding block */
1159                                 if((off_t)chain->tail->data->length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH == delta) {
1160                                         chain_delete_node_(chain, chain->tail);
1161                                         current_length = chain_calculate_length_(chain);
1162                                         FLAC__ASSERT(current_length == chain->initial_length);
1163                                 }
1164                                 /* if there is at least 'delta' bytes of padding, trim the padding down */
1165                                 else if((off_t)chain->tail->data->length >= delta) {
1166                                         chain->tail->data->length -= delta;
1167                                         current_length -= delta;
1168                                         FLAC__ASSERT(current_length == chain->initial_length);
1169                                 }
1170                         }
1171                 }
1172         }
1173
1174         return current_length;
1175 }
1176
1177 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)
1178 {
1179         FLAC__Metadata_Node *node;
1180
1181         FLAC__ASSERT(0 != chain);
1182
1183         /* we assume we're already at the beginning of the file */
1184
1185         switch(seek_to_first_metadata_block_cb_(handle, read_cb, seek_cb)) {
1186                 case 0:
1187                         break;
1188                 case 1:
1189                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1190                         return false;
1191                 case 2:
1192                         chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1193                         return false;
1194                 case 3:
1195                         chain->status = FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE;
1196                         return false;
1197                 default:
1198                         FLAC__ASSERT(0);
1199                         return false;
1200         }
1201
1202         {
1203                 FLAC__int64 pos = tell_cb(handle);
1204                 if(pos < 0) {
1205                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1206                         return false;
1207                 }
1208                 chain->first_offset = (off_t)pos;
1209         }
1210
1211         {
1212                 FLAC__bool is_last;
1213                 FLAC__MetadataType type;
1214                 unsigned length;
1215
1216                 do {
1217                         node = node_new_();
1218                         if(0 == node) {
1219                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1220                                 return false;
1221                         }
1222
1223                         if(!read_metadata_block_header_cb_(handle, read_cb, &is_last, &type, &length)) {
1224                                 node_delete_(node);
1225                                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1226                                 return false;
1227                         }
1228
1229                         node->data = FLAC__metadata_object_new(type);
1230                         if(0 == node->data) {
1231                                 node_delete_(node);
1232                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1233                                 return false;
1234                         }
1235
1236                         node->data->is_last = is_last;
1237                         node->data->length = length;
1238
1239                         chain->status = get_equivalent_status_(read_metadata_block_data_cb_(handle, read_cb, seek_cb, node->data));
1240                         if(chain->status != FLAC__METADATA_CHAIN_STATUS_OK) {
1241                                 node_delete_(node);
1242                                 return false;
1243                         }
1244                         chain_append_node_(chain, node);
1245                 } while(!is_last);
1246         }
1247
1248         {
1249                 FLAC__int64 pos = tell_cb(handle);
1250                 if(pos < 0) {
1251                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1252                         return false;
1253                 }
1254                 chain->last_offset = (off_t)pos;
1255         }
1256
1257         chain->initial_length = chain_calculate_length_(chain);
1258
1259         return true;
1260 }
1261
1262 static FLAC__StreamDecoderReadStatus chain_read_ogg_read_cb_(const FLAC__StreamDecoder *decoder, FLAC__byte buffer[], size_t *bytes, void *client_data)
1263 {
1264         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1265         (void)decoder;
1266         if(*bytes > 0 && chain->status == FLAC__METADATA_CHAIN_STATUS_OK) {
1267                 *bytes = chain->read_cb(buffer, sizeof(FLAC__byte), *bytes, chain->handle);
1268                 if(*bytes == 0)
1269                         return FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM;
1270                 else
1271                         return FLAC__STREAM_DECODER_READ_STATUS_CONTINUE;
1272         }
1273         else
1274                 return FLAC__STREAM_DECODER_READ_STATUS_ABORT;
1275 }
1276
1277 static FLAC__StreamDecoderWriteStatus chain_read_ogg_write_cb_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
1278 {
1279         (void)decoder, (void)frame, (void)buffer, (void)client_data;
1280         return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
1281 }
1282
1283 static void chain_read_ogg_metadata_cb_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
1284 {
1285         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1286         FLAC__Metadata_Node *node;
1287
1288         (void)decoder;
1289
1290         node = node_new_();
1291         if(0 == node) {
1292                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1293                 return;
1294         }
1295
1296         node->data = FLAC__metadata_object_clone(metadata);
1297         if(0 == node->data) {
1298                 node_delete_(node);
1299                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1300                 return;
1301         }
1302
1303         chain_append_node_(chain, node);
1304 }
1305
1306 static void chain_read_ogg_error_cb_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
1307 {
1308         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1309         (void)decoder, (void)status;
1310         chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1311 }
1312
1313 static FLAC__bool chain_read_ogg_cb_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb)
1314 {
1315         FLAC__StreamDecoder *decoder;
1316
1317         FLAC__ASSERT(0 != chain);
1318
1319         /* we assume we're already at the beginning of the file */
1320
1321         chain->handle = handle;
1322         chain->read_cb = read_cb;
1323         if(0 == (decoder = FLAC__stream_decoder_new())) {
1324                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1325                 return false;
1326         }
1327         FLAC__stream_decoder_set_metadata_respond_all(decoder);
1328         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) {
1329                 FLAC__stream_decoder_delete(decoder);
1330                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1331                 return false;
1332         }
1333
1334         chain->first_offset = 0; /*@@@ wrong; will need to be set correctly to implement metadata writing for Ogg FLAC */
1335
1336         if(!FLAC__stream_decoder_process_until_end_of_metadata(decoder))
1337                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1338         if(chain->status != FLAC__METADATA_CHAIN_STATUS_OK) {
1339                 FLAC__stream_decoder_delete(decoder);
1340                 return false;
1341         }
1342
1343         FLAC__stream_decoder_delete(decoder);
1344
1345         chain->last_offset = 0; /*@@@ wrong; will need to be set correctly to implement metadata writing for Ogg FLAC */
1346
1347         chain->initial_length = chain_calculate_length_(chain);
1348
1349         return true;
1350 }
1351
1352 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)
1353 {
1354         FLAC__Metadata_Node *node;
1355
1356         FLAC__ASSERT(0 != chain);
1357         FLAC__ASSERT(0 != chain->head);
1358
1359         if(0 != seek_cb(handle, chain->first_offset, SEEK_SET)) {
1360                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1361                 return false;
1362         }
1363
1364         for(node = chain->head; node; node = node->next) {
1365                 if(!write_metadata_block_header_cb_(handle, write_cb, node->data)) {
1366                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1367                         return false;
1368                 }
1369                 if(!write_metadata_block_data_cb_(handle, write_cb, node->data)) {
1370                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1371                         return false;
1372                 }
1373         }
1374
1375         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1376
1377         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
1378         return true;
1379 }
1380
1381 static FLAC__bool chain_rewrite_metadata_in_place_(FLAC__Metadata_Chain *chain)
1382 {
1383         FILE *file;
1384         FLAC__bool ret;
1385
1386         FLAC__ASSERT(0 != chain->filename);
1387
1388         if(0 == (file = fopen(chain->filename, "r+b"))) {
1389                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1390                 return false;
1391         }
1392
1393         /* chain_rewrite_metadata_in_place_cb_() sets chain->status for us */
1394         ret = chain_rewrite_metadata_in_place_cb_(chain, (FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, fseek_wrapper_);
1395
1396         fclose(file);
1397
1398         return ret;
1399 }
1400
1401 static FLAC__bool chain_rewrite_file_(FLAC__Metadata_Chain *chain, const char *tempfile_path_prefix)
1402 {
1403         FILE *f, *tempfile;
1404         char *tempfilename;
1405         FLAC__Metadata_SimpleIteratorStatus status;
1406         const FLAC__Metadata_Node *node;
1407
1408         FLAC__ASSERT(0 != chain);
1409         FLAC__ASSERT(0 != chain->filename);
1410         FLAC__ASSERT(0 != chain->head);
1411
1412         /* copy the file prefix (data up to first metadata block */
1413         if(0 == (f = fopen(chain->filename, "rb"))) {
1414                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1415                 return false;
1416         }
1417         if(!open_tempfile_(chain->filename, tempfile_path_prefix, &tempfile, &tempfilename, &status)) {
1418                 chain->status = get_equivalent_status_(status);
1419                 goto err;
1420         }
1421         if(!copy_n_bytes_from_file_(f, tempfile, chain->first_offset, &status)) {
1422                 chain->status = get_equivalent_status_(status);
1423                 goto err;
1424         }
1425
1426         /* write the metadata */
1427         for(node = chain->head; node; node = node->next) {
1428                 if(!write_metadata_block_header_(tempfile, &status, node->data)) {
1429                         chain->status = get_equivalent_status_(status);
1430                         goto err;
1431                 }
1432                 if(!write_metadata_block_data_(tempfile, &status, node->data)) {
1433                         chain->status = get_equivalent_status_(status);
1434                         goto err;
1435                 }
1436         }
1437         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1438
1439         /* copy the file postfix (everything after the metadata) */
1440         if(0 != fseeko(f, chain->last_offset, SEEK_SET)) {
1441                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1442                 goto err;
1443         }
1444         if(!copy_remaining_bytes_from_file_(f, tempfile, &status)) {
1445                 chain->status = get_equivalent_status_(status);
1446                 goto err;
1447         }
1448
1449         /* move the tempfile on top of the original */
1450         (void)fclose(f);
1451         if(!transport_tempfile_(chain->filename, &tempfile, &tempfilename, &status))
1452                 return false;
1453
1454         return true;
1455
1456 err:
1457         (void)fclose(f);
1458         cleanup_tempfile_(&tempfile, &tempfilename);
1459         return false;
1460 }
1461
1462 /* assumes 'handle' is already at beginning of file */
1463 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)
1464 {
1465         FLAC__Metadata_SimpleIteratorStatus status;
1466         const FLAC__Metadata_Node *node;
1467
1468         FLAC__ASSERT(0 != chain);
1469         FLAC__ASSERT(0 == chain->filename);
1470         FLAC__ASSERT(0 != chain->head);
1471
1472         /* copy the file prefix (data up to first metadata block */
1473         if(!copy_n_bytes_from_file_cb_(handle, read_cb, temp_handle, temp_write_cb, chain->first_offset, &status)) {
1474                 chain->status = get_equivalent_status_(status);
1475                 return false;
1476         }
1477
1478         /* write the metadata */
1479         for(node = chain->head; node; node = node->next) {
1480                 if(!write_metadata_block_header_cb_(temp_handle, temp_write_cb, node->data)) {
1481                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1482                         return false;
1483                 }
1484                 if(!write_metadata_block_data_cb_(temp_handle, temp_write_cb, node->data)) {
1485                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1486                         return false;
1487                 }
1488         }
1489         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1490
1491         /* copy the file postfix (everything after the metadata) */
1492         if(0 != seek_cb(handle, chain->last_offset, SEEK_SET)) {
1493                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1494                 return false;
1495         }
1496         if(!copy_remaining_bytes_from_file_cb_(handle, read_cb, eof_cb, temp_handle, temp_write_cb, &status)) {
1497                 chain->status = get_equivalent_status_(status);
1498                 return false;
1499         }
1500
1501         return true;
1502 }
1503
1504 FLAC_API FLAC__Metadata_Chain *FLAC__metadata_chain_new(void)
1505 {
1506         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)calloc(1, sizeof(FLAC__Metadata_Chain));
1507
1508         if(0 != chain)
1509                 chain_init_(chain);
1510
1511         return chain;
1512 }
1513
1514 FLAC_API void FLAC__metadata_chain_delete(FLAC__Metadata_Chain *chain)
1515 {
1516         FLAC__ASSERT(0 != chain);
1517
1518         chain_clear_(chain);
1519
1520         free(chain);
1521 }
1522
1523 FLAC_API FLAC__Metadata_ChainStatus FLAC__metadata_chain_status(FLAC__Metadata_Chain *chain)
1524 {
1525         FLAC__Metadata_ChainStatus status;
1526
1527         FLAC__ASSERT(0 != chain);
1528
1529         status = chain->status;
1530         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
1531         return status;
1532 }
1533
1534 static FLAC__bool chain_read_(FLAC__Metadata_Chain *chain, const char *filename, FLAC__bool is_ogg)
1535 {
1536         FILE *file;
1537         FLAC__bool ret;
1538
1539         FLAC__ASSERT(0 != chain);
1540         FLAC__ASSERT(0 != filename);
1541
1542         chain_clear_(chain);
1543
1544         if(0 == (chain->filename = strdup(filename))) {
1545                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1546                 return false;
1547         }
1548
1549         chain->is_ogg = is_ogg;
1550
1551         if(0 == (file = fopen(filename, "rb"))) {
1552                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1553                 return false;
1554         }
1555
1556         /* the function also sets chain->status for us */
1557         ret = is_ogg?
1558                 chain_read_ogg_cb_(chain, file, (FLAC__IOCallback_Read)fread) :
1559                 chain_read_cb_(chain, file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, ftell_wrapper_)
1560         ;
1561
1562         fclose(file);
1563
1564         return ret;
1565 }
1566
1567 FLAC_API FLAC__bool FLAC__metadata_chain_read(FLAC__Metadata_Chain *chain, const char *filename)
1568 {
1569         return chain_read_(chain, filename, /*is_ogg=*/false);
1570 }
1571
1572 /*@@@@add to tests*/
1573 FLAC_API FLAC__bool FLAC__metadata_chain_read_ogg(FLAC__Metadata_Chain *chain, const char *filename)
1574 {
1575         return chain_read_(chain, filename, /*is_ogg=*/true);
1576 }
1577
1578 static FLAC__bool chain_read_with_callbacks_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks, FLAC__bool is_ogg)
1579 {
1580         FLAC__bool ret;
1581
1582         FLAC__ASSERT(0 != chain);
1583
1584         chain_clear_(chain);
1585
1586         if (0 == callbacks.read || 0 == callbacks.seek || 0 == callbacks.tell) {
1587                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1588                 return false;
1589         }
1590
1591         chain->is_ogg = is_ogg;
1592
1593         /* rewind */
1594         if(0 != callbacks.seek(handle, 0, SEEK_SET)) {
1595                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1596                 return false;
1597         }
1598
1599         /* the function also sets chain->status for us */
1600         ret = is_ogg?
1601                 chain_read_ogg_cb_(chain, handle, callbacks.read) :
1602                 chain_read_cb_(chain, handle, callbacks.read, callbacks.seek, callbacks.tell)
1603         ;
1604
1605         return ret;
1606 }
1607
1608 FLAC_API FLAC__bool FLAC__metadata_chain_read_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1609 {
1610         return chain_read_with_callbacks_(chain, handle, callbacks, /*is_ogg=*/false);
1611 }
1612
1613 /*@@@@add to tests*/
1614 FLAC_API FLAC__bool FLAC__metadata_chain_read_ogg_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1615 {
1616         return chain_read_with_callbacks_(chain, handle, callbacks, /*is_ogg=*/true);
1617 }
1618
1619 FLAC_API FLAC__bool FLAC__metadata_chain_check_if_tempfile_needed(FLAC__Metadata_Chain *chain, FLAC__bool use_padding)
1620 {
1621         /* This does all the same checks that are in chain_prepare_for_write_()
1622          * but doesn't actually alter the chain.  Make sure to update the logic
1623          * here if chain_prepare_for_write_() changes.
1624          */
1625         const off_t current_length = chain_calculate_length_(chain);
1626
1627         FLAC__ASSERT(0 != chain);
1628
1629         if(use_padding) {
1630                 /* if the metadata shrank and the last block is padding, we just extend the last padding block */
1631                 if(current_length < chain->initial_length && chain->tail->data->type == FLAC__METADATA_TYPE_PADDING)
1632                         return false;
1633                 /* if the metadata shrank more than 4 bytes then there's room to add another padding block */
1634                 else if(current_length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH <= chain->initial_length)
1635                         return false;
1636                 /* 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 */
1637                 else if(current_length > chain->initial_length) {
1638                         const off_t delta = current_length - chain->initial_length;
1639                         if(chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1640                                 /* if the delta is exactly the size of the last padding block, remove the padding block */
1641                                 if((off_t)chain->tail->data->length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH == delta)
1642                                         return false;
1643                                 /* if there is at least 'delta' bytes of padding, trim the padding down */
1644                                 else if((off_t)chain->tail->data->length >= delta)
1645                                         return false;
1646                         }
1647                 }
1648         }
1649
1650         return (current_length != chain->initial_length);
1651 }
1652
1653 FLAC_API FLAC__bool FLAC__metadata_chain_write(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__bool preserve_file_stats)
1654 {
1655         struct stat stats;
1656         const char *tempfile_path_prefix = 0;
1657         off_t current_length;
1658
1659         FLAC__ASSERT(0 != chain);
1660
1661         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1662                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1663                 return false;
1664         }
1665
1666         if (0 == chain->filename) {
1667                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1668                 return false;
1669         }
1670
1671         current_length = chain_prepare_for_write_(chain, use_padding);
1672
1673         /* a return value of 0 means there was an error; chain->status is already set */
1674         if (0 == current_length)
1675                 return false;
1676
1677         if(preserve_file_stats)
1678                 get_file_stats_(chain->filename, &stats);
1679
1680         if(current_length == chain->initial_length) {
1681                 if(!chain_rewrite_metadata_in_place_(chain))
1682                         return false;
1683         }
1684         else {
1685                 if(!chain_rewrite_file_(chain, tempfile_path_prefix))
1686                         return false;
1687
1688                 /* recompute lengths and offsets */
1689                 {
1690                         const FLAC__Metadata_Node *node;
1691                         chain->initial_length = current_length;
1692                         chain->last_offset = chain->first_offset;
1693                         for(node = chain->head; node; node = node->next)
1694                                 chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1695                 }
1696         }
1697
1698         if(preserve_file_stats)
1699                 set_file_stats_(chain->filename, &stats);
1700
1701         return true;
1702 }
1703
1704 FLAC_API FLAC__bool FLAC__metadata_chain_write_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1705 {
1706         off_t current_length;
1707
1708         FLAC__ASSERT(0 != chain);
1709
1710         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1711                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1712                 return false;
1713         }
1714
1715         if (0 != chain->filename) {
1716                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1717                 return false;
1718         }
1719
1720         if (0 == callbacks.write || 0 == callbacks.seek) {
1721                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1722                 return false;
1723         }
1724
1725         if (FLAC__metadata_chain_check_if_tempfile_needed(chain, use_padding)) {
1726                 chain->status = FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL;
1727                 return false;
1728         }
1729
1730         current_length = chain_prepare_for_write_(chain, use_padding);
1731
1732         /* a return value of 0 means there was an error; chain->status is already set */
1733         if (0 == current_length)
1734                 return false;
1735
1736         FLAC__ASSERT(current_length == chain->initial_length);
1737
1738         return chain_rewrite_metadata_in_place_cb_(chain, handle, callbacks.write, callbacks.seek);
1739 }
1740
1741 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)
1742 {
1743         off_t current_length;
1744
1745         FLAC__ASSERT(0 != chain);
1746
1747         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1748                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1749                 return false;
1750         }
1751
1752         if (0 != chain->filename) {
1753                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1754                 return false;
1755         }
1756
1757         if (0 == callbacks.read || 0 == callbacks.seek || 0 == callbacks.eof) {
1758                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1759                 return false;
1760         }
1761         if (0 == temp_callbacks.write) {
1762                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1763                 return false;
1764         }
1765
1766         if (!FLAC__metadata_chain_check_if_tempfile_needed(chain, use_padding)) {
1767                 chain->status = FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL;
1768                 return false;
1769         }
1770
1771         current_length = chain_prepare_for_write_(chain, use_padding);
1772
1773         /* a return value of 0 means there was an error; chain->status is already set */
1774         if (0 == current_length)
1775                 return false;
1776
1777         FLAC__ASSERT(current_length != chain->initial_length);
1778
1779         /* rewind */
1780         if(0 != callbacks.seek(handle, 0, SEEK_SET)) {
1781                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1782                 return false;
1783         }
1784
1785         if(!chain_rewrite_file_cb_(chain, handle, callbacks.read, callbacks.seek, callbacks.eof, temp_handle, temp_callbacks.write))
1786                 return false;
1787
1788         /* recompute lengths and offsets */
1789         {
1790                 const FLAC__Metadata_Node *node;
1791                 chain->initial_length = current_length;
1792                 chain->last_offset = chain->first_offset;
1793                 for(node = chain->head; node; node = node->next)
1794                         chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1795         }
1796
1797         return true;
1798 }
1799
1800 FLAC_API void FLAC__metadata_chain_merge_padding(FLAC__Metadata_Chain *chain)
1801 {
1802         FLAC__Metadata_Node *node;
1803
1804         FLAC__ASSERT(0 != chain);
1805
1806         for(node = chain->head; node; ) {
1807                 if(!chain_merge_adjacent_padding_(chain, node))
1808                         node = node->next;
1809         }
1810 }
1811
1812 FLAC_API void FLAC__metadata_chain_sort_padding(FLAC__Metadata_Chain *chain)
1813 {
1814         FLAC__Metadata_Node *node, *save;
1815         unsigned i;
1816
1817         FLAC__ASSERT(0 != chain);
1818
1819         /*
1820          * Don't try and be too smart... this simple algo is good enough for
1821          * the small number of nodes that we deal with.
1822          */
1823         for(i = 0, node = chain->head; i < chain->nodes; i++) {
1824                 if(node->data->type == FLAC__METADATA_TYPE_PADDING) {
1825                         save = node->next;
1826                         chain_remove_node_(chain, node);
1827                         chain_append_node_(chain, node);
1828                         node = save;
1829                 }
1830                 else {
1831                         node = node->next;
1832                 }
1833         }
1834
1835         FLAC__metadata_chain_merge_padding(chain);
1836 }
1837
1838
1839 FLAC_API FLAC__Metadata_Iterator *FLAC__metadata_iterator_new(void)
1840 {
1841         FLAC__Metadata_Iterator *iterator = (FLAC__Metadata_Iterator*)calloc(1, sizeof(FLAC__Metadata_Iterator));
1842
1843         /* calloc() implies:
1844                 iterator->current = 0;
1845                 iterator->chain = 0;
1846         */
1847
1848         return iterator;
1849 }
1850
1851 FLAC_API void FLAC__metadata_iterator_delete(FLAC__Metadata_Iterator *iterator)
1852 {
1853         FLAC__ASSERT(0 != iterator);
1854
1855         free(iterator);
1856 }
1857
1858 FLAC_API void FLAC__metadata_iterator_init(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Chain *chain)
1859 {
1860         FLAC__ASSERT(0 != iterator);
1861         FLAC__ASSERT(0 != chain);
1862         FLAC__ASSERT(0 != chain->head);
1863
1864         iterator->chain = chain;
1865         iterator->current = chain->head;
1866 }
1867
1868 FLAC_API FLAC__bool FLAC__metadata_iterator_next(FLAC__Metadata_Iterator *iterator)
1869 {
1870         FLAC__ASSERT(0 != iterator);
1871
1872         if(0 == iterator->current || 0 == iterator->current->next)
1873                 return false;
1874
1875         iterator->current = iterator->current->next;
1876         return true;
1877 }
1878
1879 FLAC_API FLAC__bool FLAC__metadata_iterator_prev(FLAC__Metadata_Iterator *iterator)
1880 {
1881         FLAC__ASSERT(0 != iterator);
1882
1883         if(0 == iterator->current || 0 == iterator->current->prev)
1884                 return false;
1885
1886         iterator->current = iterator->current->prev;
1887         return true;
1888 }
1889
1890 FLAC_API FLAC__MetadataType FLAC__metadata_iterator_get_block_type(const FLAC__Metadata_Iterator *iterator)
1891 {
1892         FLAC__ASSERT(0 != iterator);
1893         FLAC__ASSERT(0 != iterator->current);
1894         FLAC__ASSERT(0 != iterator->current->data);
1895
1896         return iterator->current->data->type;
1897 }
1898
1899 FLAC_API FLAC__StreamMetadata *FLAC__metadata_iterator_get_block(FLAC__Metadata_Iterator *iterator)
1900 {
1901         FLAC__ASSERT(0 != iterator);
1902         FLAC__ASSERT(0 != iterator->current);
1903
1904         return iterator->current->data;
1905 }
1906
1907 FLAC_API FLAC__bool FLAC__metadata_iterator_set_block(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1908 {
1909         FLAC__ASSERT(0 != iterator);
1910         FLAC__ASSERT(0 != block);
1911         return FLAC__metadata_iterator_delete_block(iterator, false) && FLAC__metadata_iterator_insert_block_after(iterator, block);
1912 }
1913
1914 FLAC_API FLAC__bool FLAC__metadata_iterator_delete_block(FLAC__Metadata_Iterator *iterator, FLAC__bool replace_with_padding)
1915 {
1916         FLAC__Metadata_Node *save;
1917
1918         FLAC__ASSERT(0 != iterator);
1919         FLAC__ASSERT(0 != iterator->current);
1920
1921         if(0 == iterator->current->prev) {
1922                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1923                 return false;
1924         }
1925
1926         save = iterator->current->prev;
1927
1928         if(replace_with_padding) {
1929                 FLAC__metadata_object_delete_data(iterator->current->data);
1930                 iterator->current->data->type = FLAC__METADATA_TYPE_PADDING;
1931         }
1932         else {
1933                 chain_delete_node_(iterator->chain, iterator->current);
1934         }
1935
1936         iterator->current = save;
1937         return true;
1938 }
1939
1940 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_before(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1941 {
1942         FLAC__Metadata_Node *node;
1943
1944         FLAC__ASSERT(0 != iterator);
1945         FLAC__ASSERT(0 != iterator->current);
1946         FLAC__ASSERT(0 != block);
1947
1948         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1949                 return false;
1950
1951         if(0 == iterator->current->prev) {
1952                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1953                 return false;
1954         }
1955
1956         if(0 == (node = node_new_()))
1957                 return false;
1958
1959         node->data = block;
1960         iterator_insert_node_(iterator, node);
1961         iterator->current = node;
1962         return true;
1963 }
1964
1965 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_after(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1966 {
1967         FLAC__Metadata_Node *node;
1968
1969         FLAC__ASSERT(0 != iterator);
1970         FLAC__ASSERT(0 != iterator->current);
1971         FLAC__ASSERT(0 != block);
1972
1973         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1974                 return false;
1975
1976         if(0 == (node = node_new_()))
1977                 return false;
1978
1979         node->data = block;
1980         iterator_insert_node_after_(iterator, node);
1981         iterator->current = node;
1982         return true;
1983 }
1984
1985
1986 /****************************************************************************
1987  *
1988  * Local function definitions
1989  *
1990  ***************************************************************************/
1991
1992 void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
1993 {
1994         unsigned i;
1995
1996         b += bytes;
1997
1998         for(i = 0; i < bytes; i++) {
1999                 *(--b) = (FLAC__byte)(val & 0xff);
2000                 val >>= 8;
2001         }
2002 }
2003
2004 void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
2005 {
2006         unsigned i;
2007
2008         for(i = 0; i < bytes; i++) {
2009                 *(b++) = (FLAC__byte)(val & 0xff);
2010                 val >>= 8;
2011         }
2012 }
2013
2014 void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes)
2015 {
2016         unsigned i;
2017
2018         b += bytes;
2019
2020         for(i = 0; i < bytes; i++) {
2021                 *(--b) = (FLAC__byte)(val & 0xff);
2022                 val >>= 8;
2023         }
2024 }
2025
2026 FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes)
2027 {
2028         FLAC__uint32 ret = 0;
2029         unsigned i;
2030
2031         for(i = 0; i < bytes; i++)
2032                 ret = (ret << 8) | (FLAC__uint32)(*b++);
2033
2034         return ret;
2035 }
2036
2037 FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes)
2038 {
2039         FLAC__uint32 ret = 0;
2040         unsigned i;
2041
2042         b += bytes;
2043
2044         for(i = 0; i < bytes; i++)
2045                 ret = (ret << 8) | (FLAC__uint32)(*--b);
2046
2047         return ret;
2048 }
2049
2050 FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes)
2051 {
2052         FLAC__uint64 ret = 0;
2053         unsigned i;
2054
2055         for(i = 0; i < bytes; i++)
2056                 ret = (ret << 8) | (FLAC__uint64)(*b++);
2057
2058         return ret;
2059 }
2060
2061 FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator)
2062 {
2063         FLAC__ASSERT(0 != iterator);
2064         FLAC__ASSERT(0 != iterator->file);
2065
2066         if(!read_metadata_block_header_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, &iterator->is_last, &iterator->type, &iterator->length)) {
2067                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2068                 return false;
2069         }
2070
2071         return true;
2072 }
2073
2074 FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block)
2075 {
2076         FLAC__ASSERT(0 != iterator);
2077         FLAC__ASSERT(0 != iterator->file);
2078
2079         iterator->status = read_metadata_block_data_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, block);
2080
2081         return (iterator->status == FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK);
2082 }
2083
2084 FLAC__bool read_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__bool *is_last, FLAC__MetadataType *type, unsigned *length)
2085 {
2086         FLAC__byte raw_header[FLAC__STREAM_METADATA_HEADER_LENGTH];
2087
2088         if(read_cb(raw_header, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
2089                 return false;
2090
2091         *is_last = raw_header[0] & 0x80? true : false;
2092         *type = (FLAC__MetadataType)(raw_header[0] & 0x7f);
2093         *length = unpack_uint32_(raw_header + 1, 3);
2094
2095         /* Note that we don't check:
2096          *    if(iterator->type >= FLAC__METADATA_TYPE_UNDEFINED)
2097          * we just will read in an opaque block
2098          */
2099
2100         return true;
2101 }
2102
2103 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata *block)
2104 {
2105         switch(block->type) {
2106                 case FLAC__METADATA_TYPE_STREAMINFO:
2107                         return read_metadata_block_data_streaminfo_cb_(handle, read_cb, &block->data.stream_info);
2108                 case FLAC__METADATA_TYPE_PADDING:
2109                         return read_metadata_block_data_padding_cb_(handle, seek_cb, &block->data.padding, block->length);
2110                 case FLAC__METADATA_TYPE_APPLICATION:
2111                         return read_metadata_block_data_application_cb_(handle, read_cb, &block->data.application, block->length);
2112                 case FLAC__METADATA_TYPE_SEEKTABLE:
2113                         return read_metadata_block_data_seektable_cb_(handle, read_cb, &block->data.seek_table, block->length);
2114                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
2115                         return read_metadata_block_data_vorbis_comment_cb_(handle, read_cb, &block->data.vorbis_comment);
2116                 case FLAC__METADATA_TYPE_CUESHEET:
2117                         return read_metadata_block_data_cuesheet_cb_(handle, read_cb, &block->data.cue_sheet);
2118                 case FLAC__METADATA_TYPE_PICTURE:
2119                         return read_metadata_block_data_picture_cb_(handle, read_cb, &block->data.picture);
2120                 default:
2121                         return read_metadata_block_data_unknown_cb_(handle, read_cb, &block->data.unknown, block->length);
2122         }
2123 }
2124
2125 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_StreamInfo *block)
2126 {
2127         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH], *b;
2128
2129         if(read_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
2130                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2131
2132         b = buffer;
2133
2134         /* we are using hardcoded numbers for simplicity but we should
2135          * probably eventually write a bit-level unpacker and use the
2136          * _STREAMINFO_ constants.
2137          */
2138         block->min_blocksize = unpack_uint32_(b, 2); b += 2;
2139         block->max_blocksize = unpack_uint32_(b, 2); b += 2;
2140         block->min_framesize = unpack_uint32_(b, 3); b += 3;
2141         block->max_framesize = unpack_uint32_(b, 3); b += 3;
2142         block->sample_rate = (unpack_uint32_(b, 2) << 4) | ((unsigned)(b[2] & 0xf0) >> 4);
2143         block->channels = (unsigned)((b[2] & 0x0e) >> 1) + 1;
2144         block->bits_per_sample = ((((unsigned)(b[2] & 0x01)) << 4) | (((unsigned)(b[3] & 0xf0)) >> 4)) + 1;
2145         block->total_samples = (((FLAC__uint64)(b[3] & 0x0f)) << 32) | unpack_uint64_(b+4, 4);
2146         memcpy(block->md5sum, b+8, 16);
2147
2148         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2149 }
2150
2151 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata_Padding *block, unsigned block_length)
2152 {
2153         (void)block; /* nothing to do; we don't care about reading the padding bytes */
2154
2155         if(0 != seek_cb(handle, block_length, SEEK_CUR))
2156                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2157
2158         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2159 }
2160
2161 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Application *block, unsigned block_length)
2162 {
2163         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
2164
2165         if(read_cb(block->id, 1, id_bytes, handle) != id_bytes)
2166                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2167
2168         if(block_length < id_bytes)
2169                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2170
2171         block_length -= id_bytes;
2172
2173         if(block_length == 0) {
2174                 block->data = 0;
2175         }
2176         else {
2177                 if(0 == (block->data = (FLAC__byte*)malloc(block_length)))
2178                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2179
2180                 if(read_cb(block->data, 1, block_length, handle) != block_length)
2181                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2182         }
2183
2184         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2185 }
2186
2187 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_SeekTable *block, unsigned block_length)
2188 {
2189         unsigned i;
2190         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
2191
2192         FLAC__ASSERT(block_length % FLAC__STREAM_METADATA_SEEKPOINT_LENGTH == 0);
2193
2194         block->num_points = block_length / FLAC__STREAM_METADATA_SEEKPOINT_LENGTH;
2195
2196         if(block->num_points == 0)
2197                 block->points = 0;
2198         else if(0 == (block->points = (FLAC__StreamMetadata_SeekPoint*)safe_malloc_mul_2op_(block->num_points, /*times*/sizeof(FLAC__StreamMetadata_SeekPoint))))
2199                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2200
2201         for(i = 0; i < block->num_points; i++) {
2202                 if(read_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
2203                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2204                 /* some MAGIC NUMBERs here */
2205                 block->points[i].sample_number = unpack_uint64_(buffer, 8);
2206                 block->points[i].stream_offset = unpack_uint64_(buffer+8, 8);
2207                 block->points[i].frame_samples = unpack_uint32_(buffer+16, 2);
2208         }
2209
2210         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2211 }
2212
2213 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_entry_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment_Entry *entry)
2214 {
2215         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
2216         FLAC__byte buffer[4]; /* magic number is asserted below */
2217
2218         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8 == sizeof(buffer));
2219
2220         if(read_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2221                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2222         entry->length = unpack_uint32_little_endian_(buffer, entry_length_len);
2223
2224         if(0 != entry->entry)
2225                 free(entry->entry);
2226
2227         if(entry->length == 0) {
2228                 entry->entry = 0;
2229         }
2230         else {
2231                 if(0 == (entry->entry = (FLAC__byte*)safe_malloc_add_2op_(entry->length, /*+*/1)))
2232                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2233
2234                 if(read_cb(entry->entry, 1, entry->length, handle) != entry->length)
2235                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2236
2237                 entry->entry[entry->length] = '\0';
2238         }
2239
2240         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2241 }
2242
2243 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment *block)
2244 {
2245         unsigned i;
2246         FLAC__Metadata_SimpleIteratorStatus status;
2247         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2248         FLAC__byte buffer[4]; /* magic number is asserted below */
2249
2250         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8 == sizeof(buffer));
2251
2252         if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, &(block->vendor_string))))
2253                 return status;
2254
2255         if(read_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2256                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2257         block->num_comments = unpack_uint32_little_endian_(buffer, num_comments_len);
2258
2259         if(block->num_comments == 0) {
2260                 block->comments = 0;
2261         }
2262         else if(0 == (block->comments = (FLAC__StreamMetadata_VorbisComment_Entry*)calloc(block->num_comments, sizeof(FLAC__StreamMetadata_VorbisComment_Entry))))
2263                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2264
2265         for(i = 0; i < block->num_comments; i++) {
2266                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, block->comments + i)))
2267                         return status;
2268         }
2269
2270         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2271 }
2272
2273 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet_Track *track)
2274 {
2275         unsigned i, len;
2276         FLAC__byte buffer[32]; /* asserted below that this is big enough */
2277
2278         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2279         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2280         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);
2281
2282         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2283         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2284         if(read_cb(buffer, 1, len, handle) != len)
2285                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2286         track->offset = unpack_uint64_(buffer, len);
2287
2288         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2289         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2290         if(read_cb(buffer, 1, len, handle) != len)
2291                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2292         track->number = (FLAC__byte)unpack_uint32_(buffer, len);
2293
2294         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2295         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2296         if(read_cb(track->isrc, 1, len, handle) != len)
2297                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2298
2299         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);
2300         len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2301         if(read_cb(buffer, 1, len, handle) != len)
2302                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2303         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN == 1);
2304         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN == 1);
2305         track->type = buffer[0] >> 7;
2306         track->pre_emphasis = (buffer[0] >> 6) & 1;
2307
2308         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2309         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2310         if(read_cb(buffer, 1, len, handle) != len)
2311                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2312         track->num_indices = (FLAC__byte)unpack_uint32_(buffer, len);
2313
2314         if(track->num_indices == 0) {
2315                 track->indices = 0;
2316         }
2317         else if(0 == (track->indices = (FLAC__StreamMetadata_CueSheet_Index*)calloc(track->num_indices, sizeof(FLAC__StreamMetadata_CueSheet_Index))))
2318                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2319
2320         for(i = 0; i < track->num_indices; i++) {
2321                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2322                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2323                 if(read_cb(buffer, 1, len, handle) != len)
2324                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2325                 track->indices[i].offset = unpack_uint64_(buffer, len);
2326
2327                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2328                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2329                 if(read_cb(buffer, 1, len, handle) != len)
2330                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2331                 track->indices[i].number = (FLAC__byte)unpack_uint32_(buffer, len);
2332
2333                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2334                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2335                 if(read_cb(buffer, 1, len, handle) != len)
2336                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2337         }
2338
2339         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2340 }
2341
2342 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet *block)
2343 {
2344         unsigned i, len;
2345         FLAC__Metadata_SimpleIteratorStatus status;
2346         FLAC__byte buffer[1024]; /* MSVC needs a constant expression so we put a magic number and assert */
2347
2348         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN)/8 <= sizeof(buffer));
2349         FLAC__ASSERT(sizeof(FLAC__uint64) <= sizeof(buffer));
2350
2351         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2352         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2353         if(read_cb(block->media_catalog_number, 1, len, handle) != len)
2354                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2355
2356         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2357         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2358         if(read_cb(buffer, 1, len, handle) != len)
2359                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2360         block->lead_in = unpack_uint64_(buffer, len);
2361
2362         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2363         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2364         if(read_cb(buffer, 1, len, handle) != len)
2365                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2366         block->is_cd = buffer[0]&0x80? true : false;
2367
2368         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2369         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2370         if(read_cb(buffer, 1, len, handle) != len)
2371                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2372         block->num_tracks = unpack_uint32_(buffer, len);
2373
2374         if(block->num_tracks == 0) {
2375                 block->tracks = 0;
2376         }
2377         else if(0 == (block->tracks = (FLAC__StreamMetadata_CueSheet_Track*)calloc(block->num_tracks, sizeof(FLAC__StreamMetadata_CueSheet_Track))))
2378                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2379
2380         for(i = 0; i < block->num_tracks; i++) {
2381                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_cuesheet_track_cb_(handle, read_cb, block->tracks + i)))
2382                         return status;
2383         }
2384
2385         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2386 }
2387
2388 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)
2389 {
2390         FLAC__byte buffer[sizeof(FLAC__uint32)];
2391
2392         FLAC__ASSERT(0 != data);
2393         FLAC__ASSERT(length_len%8 == 0);
2394
2395         length_len /= 8; /* convert to bytes */
2396
2397         FLAC__ASSERT(sizeof(buffer) >= length_len);
2398
2399         if(read_cb(buffer, 1, length_len, handle) != length_len)
2400                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2401         *length = unpack_uint32_(buffer, length_len);
2402
2403         if(0 != *data)
2404                 free(*data);
2405
2406         if(0 == (*data = (FLAC__byte*)safe_malloc_add_2op_(*length, /*+*/1)))
2407                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2408
2409         if(*length > 0) {
2410                 if(read_cb(*data, 1, *length, handle) != *length)
2411                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2412         }
2413
2414         (*data)[*length] = '\0';
2415
2416         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2417 }
2418
2419 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Picture *block)
2420 {
2421         FLAC__Metadata_SimpleIteratorStatus status;
2422         FLAC__byte buffer[4]; /* asserted below that this is big enough */
2423         FLAC__uint32 len;
2424
2425         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8);
2426         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8);
2427         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8);
2428         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8);
2429         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8);
2430
2431         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_TYPE_LEN % 8 == 0);
2432         len = FLAC__STREAM_METADATA_PICTURE_TYPE_LEN / 8;
2433         if(read_cb(buffer, 1, len, handle) != len)
2434                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2435         block->type = (FLAC__StreamMetadata_Picture_Type)unpack_uint32_(buffer, len);
2436
2437         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)
2438                 return status;
2439
2440         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)
2441                 return status;
2442
2443         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN % 8 == 0);
2444         len = FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN / 8;
2445         if(read_cb(buffer, 1, len, handle) != len)
2446                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2447         block->width = unpack_uint32_(buffer, len);
2448
2449         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN % 8 == 0);
2450         len = FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN / 8;
2451         if(read_cb(buffer, 1, len, handle) != len)
2452                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2453         block->height = unpack_uint32_(buffer, len);
2454
2455         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN % 8 == 0);
2456         len = FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN / 8;
2457         if(read_cb(buffer, 1, len, handle) != len)
2458                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2459         block->depth = unpack_uint32_(buffer, len);
2460
2461         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_COLORS_LEN % 8 == 0);
2462         len = FLAC__STREAM_METADATA_PICTURE_COLORS_LEN / 8;
2463         if(read_cb(buffer, 1, len, handle) != len)
2464                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2465         block->colors = unpack_uint32_(buffer, len);
2466
2467         /* for convenience we use read_metadata_block_data_picture_cstring_cb_() even though it adds an extra terminating NUL we don't use */
2468         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)
2469                 return status;
2470
2471         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2472 }
2473
2474 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2475 {
2476         if(block_length == 0) {
2477                 block->data = 0;
2478         }
2479         else {
2480                 if(0 == (block->data = (FLAC__byte*)malloc(block_length)))
2481                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2482
2483                 if(read_cb(block->data, 1, block_length, handle) != block_length)
2484                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2485         }
2486
2487         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2488 }
2489
2490 FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2491 {
2492         FLAC__ASSERT(0 != file);
2493         FLAC__ASSERT(0 != status);
2494
2495         if(!write_metadata_block_header_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2496                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2497                 return false;
2498         }
2499
2500         return true;
2501 }
2502
2503 FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2504 {
2505         FLAC__ASSERT(0 != file);
2506         FLAC__ASSERT(0 != status);
2507
2508         if (write_metadata_block_data_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2509                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2510                 return true;
2511         }
2512         else {
2513                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2514                 return false;
2515         }
2516 }
2517
2518 FLAC__bool write_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2519 {
2520         FLAC__byte buffer[FLAC__STREAM_METADATA_HEADER_LENGTH];
2521
2522         FLAC__ASSERT(block->length < (1u << FLAC__STREAM_METADATA_LENGTH_LEN));
2523
2524         buffer[0] = (block->is_last? 0x80 : 0) | (FLAC__byte)block->type;
2525         pack_uint32_(block->length, buffer + 1, 3);
2526
2527         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
2528                 return false;
2529
2530         return true;
2531 }
2532
2533 FLAC__bool write_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2534 {
2535         FLAC__ASSERT(0 != block);
2536
2537         switch(block->type) {
2538                 case FLAC__METADATA_TYPE_STREAMINFO:
2539                         return write_metadata_block_data_streaminfo_cb_(handle, write_cb, &block->data.stream_info);
2540                 case FLAC__METADATA_TYPE_PADDING:
2541                         return write_metadata_block_data_padding_cb_(handle, write_cb, &block->data.padding, block->length);
2542                 case FLAC__METADATA_TYPE_APPLICATION:
2543                         return write_metadata_block_data_application_cb_(handle, write_cb, &block->data.application, block->length);
2544                 case FLAC__METADATA_TYPE_SEEKTABLE:
2545                         return write_metadata_block_data_seektable_cb_(handle, write_cb, &block->data.seek_table);
2546                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
2547                         return write_metadata_block_data_vorbis_comment_cb_(handle, write_cb, &block->data.vorbis_comment);
2548                 case FLAC__METADATA_TYPE_CUESHEET:
2549                         return write_metadata_block_data_cuesheet_cb_(handle, write_cb, &block->data.cue_sheet);
2550                 case FLAC__METADATA_TYPE_PICTURE:
2551                         return write_metadata_block_data_picture_cb_(handle, write_cb, &block->data.picture);
2552                 default:
2553                         return write_metadata_block_data_unknown_cb_(handle, write_cb, &block->data.unknown, block->length);
2554         }
2555 }
2556
2557 FLAC__bool write_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_StreamInfo *block)
2558 {
2559         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH];
2560         const unsigned channels1 = block->channels - 1;
2561         const unsigned bps1 = block->bits_per_sample - 1;
2562
2563         /* we are using hardcoded numbers for simplicity but we should
2564          * probably eventually write a bit-level packer and use the
2565          * _STREAMINFO_ constants.
2566          */
2567         pack_uint32_(block->min_blocksize, buffer, 2);
2568         pack_uint32_(block->max_blocksize, buffer+2, 2);
2569         pack_uint32_(block->min_framesize, buffer+4, 3);
2570         pack_uint32_(block->max_framesize, buffer+7, 3);
2571         buffer[10] = (block->sample_rate >> 12) & 0xff;
2572         buffer[11] = (block->sample_rate >> 4) & 0xff;
2573         buffer[12] = ((block->sample_rate & 0x0f) << 4) | (channels1 << 1) | (bps1 >> 4);
2574         buffer[13] = (FLAC__byte)(((bps1 & 0x0f) << 4) | ((block->total_samples >> 32) & 0x0f));
2575         pack_uint32_((FLAC__uint32)block->total_samples, buffer+14, 4);
2576         memcpy(buffer+18, block->md5sum, 16);
2577
2578         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
2579                 return false;
2580
2581         return true;
2582 }
2583
2584 FLAC__bool write_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Padding *block, unsigned block_length)
2585 {
2586         unsigned i, n = block_length;
2587         FLAC__byte buffer[1024];
2588
2589         (void)block;
2590
2591         memset(buffer, 0, 1024);
2592
2593         for(i = 0; i < n/1024; i++)
2594                 if(write_cb(buffer, 1, 1024, handle) != 1024)
2595                         return false;
2596
2597         n %= 1024;
2598
2599         if(write_cb(buffer, 1, n, handle) != n)
2600                 return false;
2601
2602         return true;
2603 }
2604
2605 FLAC__bool write_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Application *block, unsigned block_length)
2606 {
2607         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
2608
2609         if(write_cb(block->id, 1, id_bytes, handle) != id_bytes)
2610                 return false;
2611
2612         block_length -= id_bytes;
2613
2614         if(write_cb(block->data, 1, block_length, handle) != block_length)
2615                 return false;
2616
2617         return true;
2618 }
2619
2620 FLAC__bool write_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_SeekTable *block)
2621 {
2622         unsigned i;
2623         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
2624
2625         for(i = 0; i < block->num_points; i++) {
2626                 /* some MAGIC NUMBERs here */
2627                 pack_uint64_(block->points[i].sample_number, buffer, 8);
2628                 pack_uint64_(block->points[i].stream_offset, buffer+8, 8);
2629                 pack_uint32_(block->points[i].frame_samples, buffer+16, 2);
2630                 if(write_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
2631                         return false;
2632         }
2633
2634         return true;
2635 }
2636
2637 FLAC__bool write_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_VorbisComment *block)
2638 {
2639         unsigned i;
2640         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
2641         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2642         FLAC__byte buffer[4]; /* magic number is asserted below */
2643
2644         FLAC__ASSERT(max(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN, FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN) / 8 == sizeof(buffer));
2645
2646         pack_uint32_little_endian_(block->vendor_string.length, buffer, entry_length_len);
2647         if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2648                 return false;
2649         if(write_cb(block->vendor_string.entry, 1, block->vendor_string.length, handle) != block->vendor_string.length)
2650                 return false;
2651
2652         pack_uint32_little_endian_(block->num_comments, buffer, num_comments_len);
2653         if(write_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2654                 return false;
2655
2656         for(i = 0; i < block->num_comments; i++) {
2657                 pack_uint32_little_endian_(block->comments[i].length, buffer, entry_length_len);
2658                 if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2659                         return false;
2660                 if(write_cb(block->comments[i].entry, 1, block->comments[i].length, handle) != block->comments[i].length)
2661                         return false;
2662         }
2663
2664         return true;
2665 }
2666
2667 FLAC__bool write_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_CueSheet *block)
2668 {
2669         unsigned i, j, len;
2670         FLAC__byte buffer[1024]; /* asserted below that this is big enough */
2671
2672         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2673         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN/8);
2674         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);
2675         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2676
2677         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2678         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2679         if(write_cb(block->media_catalog_number, 1, len, handle) != len)
2680                 return false;
2681
2682         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2683         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2684         pack_uint64_(block->lead_in, buffer, len);
2685         if(write_cb(buffer, 1, len, handle) != len)
2686                 return false;
2687
2688         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2689         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2690         memset(buffer, 0, len);
2691         if(block->is_cd)
2692                 buffer[0] |= 0x80;
2693         if(write_cb(buffer, 1, len, handle) != len)
2694                 return false;
2695
2696         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2697         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2698         pack_uint32_(block->num_tracks, buffer, len);
2699         if(write_cb(buffer, 1, len, handle) != len)
2700                 return false;
2701
2702         for(i = 0; i < block->num_tracks; i++) {
2703                 FLAC__StreamMetadata_CueSheet_Track *track = block->tracks + i;
2704
2705                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2706                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2707                 pack_uint64_(track->offset, buffer, len);
2708                 if(write_cb(buffer, 1, len, handle) != len)
2709                         return false;
2710
2711                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2712                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2713                 pack_uint32_(track->number, buffer, len);
2714                 if(write_cb(buffer, 1, len, handle) != len)
2715                         return false;
2716
2717                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2718                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2719                 if(write_cb(track->isrc, 1, len, handle) != len)
2720                         return false;
2721
2722                 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);
2723                 len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2724                 memset(buffer, 0, len);
2725                 buffer[0] = (track->type << 7) | (track->pre_emphasis << 6);
2726                 if(write_cb(buffer, 1, len, handle) != len)
2727                         return false;
2728
2729                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2730                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2731                 pack_uint32_(track->num_indices, buffer, len);
2732                 if(write_cb(buffer, 1, len, handle) != len)
2733                         return false;
2734
2735                 for(j = 0; j < track->num_indices; j++) {
2736                         FLAC__StreamMetadata_CueSheet_Index *index = track->indices + j;
2737
2738                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2739                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2740                         pack_uint64_(index->offset, buffer, len);
2741                         if(write_cb(buffer, 1, len, handle) != len)
2742                                 return false;
2743
2744                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2745                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2746                         pack_uint32_(index->number, buffer, len);
2747                         if(write_cb(buffer, 1, len, handle) != len)
2748                                 return false;
2749
2750                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2751                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2752                         memset(buffer, 0, len);
2753                         if(write_cb(buffer, 1, len, handle) != len)
2754                                 return false;
2755                 }
2756         }
2757
2758         return true;
2759 }
2760
2761 FLAC__bool write_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Picture *block)
2762 {
2763         unsigned len;
2764         size_t slen;
2765         FLAC__byte buffer[4]; /* magic number is asserted below */
2766
2767         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_TYPE_LEN%8);
2768         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN%8);
2769         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN%8);
2770         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN%8);
2771         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN%8);
2772         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN%8);
2773         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_COLORS_LEN%8);
2774         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN%8);
2775         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8);
2776         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN/8);
2777         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN/8);
2778         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8);
2779         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8);
2780         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8);
2781         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8);
2782         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN/8);
2783
2784         len = FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8;
2785         pack_uint32_(block->type, buffer, len);
2786         if(write_cb(buffer, 1, len, handle) != len)
2787                 return false;
2788
2789         len = FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN/8;
2790         slen = strlen(block->mime_type);
2791         pack_uint32_(slen, buffer, len);
2792         if(write_cb(buffer, 1, len, handle) != len)
2793                 return false;
2794         if(write_cb(block->mime_type, 1, slen, handle) != slen)
2795                 return false;
2796
2797         len = FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN/8;
2798         slen = strlen((const char *)block->description);
2799         pack_uint32_(slen, buffer, len);
2800         if(write_cb(buffer, 1, len, handle) != len)
2801                 return false;
2802         if(write_cb(block->description, 1, slen, handle) != slen)
2803                 return false;
2804
2805         len = FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8;
2806         pack_uint32_(block->width, buffer, len);
2807         if(write_cb(buffer, 1, len, handle) != len)
2808                 return false;
2809
2810         len = FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8;
2811         pack_uint32_(block->height, buffer, len);
2812         if(write_cb(buffer, 1, len, handle) != len)
2813                 return false;
2814
2815         len = FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8;
2816         pack_uint32_(block->depth, buffer, len);
2817         if(write_cb(buffer, 1, len, handle) != len)
2818                 return false;
2819
2820         len = FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8;
2821         pack_uint32_(block->colors, buffer, len);
2822         if(write_cb(buffer, 1, len, handle) != len)
2823                 return false;
2824
2825         len = FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN/8;
2826         pack_uint32_(block->data_length, buffer, len);
2827         if(write_cb(buffer, 1, len, handle) != len)
2828                 return false;
2829         if(write_cb(block->data, 1, block->data_length, handle) != block->data_length)
2830                 return false;
2831
2832         return true;
2833 }
2834
2835 FLAC__bool write_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2836 {
2837         if(write_cb(block->data, 1, block_length, handle) != block_length)
2838                 return false;
2839
2840         return true;
2841 }
2842
2843 FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block)
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         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2851                 return false;
2852
2853         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2854                 return false;
2855
2856         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2857                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2858                 return false;
2859         }
2860
2861         return read_metadata_block_header_(iterator);
2862 }
2863
2864 FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last)
2865 {
2866         FLAC__StreamMetadata *padding;
2867
2868         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2869                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2870                 return false;
2871         }
2872
2873         block->is_last = false;
2874
2875         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2876                 return false;
2877
2878         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2879                 return false;
2880
2881         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING)))
2882                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2883
2884         padding->is_last = padding_is_last;
2885         padding->length = padding_length;
2886
2887         if(!write_metadata_block_header_(iterator->file, &iterator->status, padding)) {
2888                 FLAC__metadata_object_delete(padding);
2889                 return false;
2890         }
2891
2892         if(!write_metadata_block_data_(iterator->file, &iterator->status, padding)) {
2893                 FLAC__metadata_object_delete(padding);
2894                 return false;
2895         }
2896
2897         FLAC__metadata_object_delete(padding);
2898
2899         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2900                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2901                 return false;
2902         }
2903
2904         return read_metadata_block_header_(iterator);
2905 }
2906
2907 FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append)
2908 {
2909         FILE *tempfile;
2910         char *tempfilename;
2911         int fixup_is_last_code = 0; /* 0 => no need to change any is_last flags */
2912         off_t fixup_is_last_flag_offset = -1;
2913
2914         FLAC__ASSERT(0 != block || append == false);
2915
2916         if(iterator->is_last) {
2917                 if(append) {
2918                         fixup_is_last_code = 1; /* 1 => clear the is_last flag at the following offset */
2919                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2920                 }
2921                 else if(0 == block) {
2922                         simple_iterator_push_(iterator);
2923                         if(!FLAC__metadata_simple_iterator_prev(iterator)) {
2924                                 (void)simple_iterator_pop_(iterator);
2925                                 return false;
2926                         }
2927                         fixup_is_last_code = -1; /* -1 => set the is_last the flag at the following offset */
2928                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2929                         if(!simple_iterator_pop_(iterator))
2930                                 return false;
2931                 }
2932         }
2933
2934         if(!simple_iterator_copy_file_prefix_(iterator, &tempfile, &tempfilename, append))
2935                 return false;
2936
2937         if(0 != block) {
2938                 if(!write_metadata_block_header_(tempfile, &iterator->status, block)) {
2939                         cleanup_tempfile_(&tempfile, &tempfilename);
2940                         return false;
2941                 }
2942
2943                 if(!write_metadata_block_data_(tempfile, &iterator->status, block)) {
2944                         cleanup_tempfile_(&tempfile, &tempfilename);
2945                         return false;
2946                 }
2947         }
2948
2949         if(!simple_iterator_copy_file_postfix_(iterator, &tempfile, &tempfilename, fixup_is_last_code, fixup_is_last_flag_offset, block==0))
2950                 return false;
2951
2952         if(append)
2953                 return FLAC__metadata_simple_iterator_next(iterator);
2954
2955         return true;
2956 }
2957
2958 void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator)
2959 {
2960         FLAC__ASSERT(iterator->depth+1 < SIMPLE_ITERATOR_MAX_PUSH_DEPTH);
2961         iterator->offset[iterator->depth+1] = iterator->offset[iterator->depth];
2962         iterator->depth++;
2963 }
2964
2965 FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator)
2966 {
2967         FLAC__ASSERT(iterator->depth > 0);
2968         iterator->depth--;
2969         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2970                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2971                 return false;
2972         }
2973
2974         return read_metadata_block_header_(iterator);
2975 }
2976
2977 /* return meanings:
2978  * 0: ok
2979  * 1: read error
2980  * 2: seek error
2981  * 3: not a FLAC file
2982  */
2983 unsigned seek_to_first_metadata_block_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb)
2984 {
2985         FLAC__byte buffer[4];
2986         size_t n;
2987         unsigned i;
2988
2989         FLAC__ASSERT(FLAC__STREAM_SYNC_LENGTH == sizeof(buffer));
2990
2991         /* skip any id3v2 tag */
2992         errno = 0;
2993         n = read_cb(buffer, 1, 4, handle);
2994         if(errno)
2995                 return 1;
2996         else if(n != 4)
2997                 return 3;
2998         else if(0 == memcmp(buffer, "ID3", 3)) {
2999                 unsigned tag_length = 0;
3000
3001                 /* skip to the tag length */
3002                 if(seek_cb(handle, 2, SEEK_CUR) < 0)
3003                         return 2;
3004
3005                 /* read the length */
3006                 for(i = 0; i < 4; i++) {
3007                         if(read_cb(buffer, 1, 1, handle) < 1 || buffer[0] & 0x80)
3008                                 return 1;
3009                         tag_length <<= 7;
3010                         tag_length |= (buffer[0] & 0x7f);
3011                 }
3012
3013                 /* skip the rest of the tag */
3014                 if(seek_cb(handle, tag_length, SEEK_CUR) < 0)
3015                         return 2;
3016
3017                 /* read the stream sync code */
3018                 errno = 0;
3019                 n = read_cb(buffer, 1, 4, handle);
3020                 if(errno)
3021                         return 1;
3022                 else if(n != 4)
3023                         return 3;
3024         }
3025
3026         /* check for the fLaC signature */
3027         if(0 == memcmp(FLAC__STREAM_SYNC_STRING, buffer, FLAC__STREAM_SYNC_LENGTH))
3028                 return 0;
3029         else
3030                 return 3;
3031 }
3032
3033 unsigned seek_to_first_metadata_block_(FILE *f)
3034 {
3035         return seek_to_first_metadata_block_cb_((FLAC__IOHandle)f, (FLAC__IOCallback_Read)fread, fseek_wrapper_);
3036 }
3037
3038 FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append)
3039 {
3040         const off_t offset_end = append? iterator->offset[iterator->depth] + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length : iterator->offset[iterator->depth];
3041
3042         if(0 != fseeko(iterator->file, 0, SEEK_SET)) {
3043                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3044                 return false;
3045         }
3046         if(!open_tempfile_(iterator->filename, iterator->tempfile_path_prefix, tempfile, tempfilename, &iterator->status)) {
3047                 cleanup_tempfile_(tempfile, tempfilename);
3048                 return false;
3049         }
3050         if(!copy_n_bytes_from_file_(iterator->file, *tempfile, offset_end, &iterator->status)) {
3051                 cleanup_tempfile_(tempfile, tempfilename);
3052                 return false;
3053         }
3054
3055         return true;
3056 }
3057
3058 FLAC__bool simple_iterator_copy_file_postfix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, int fixup_is_last_code, off_t fixup_is_last_flag_offset, FLAC__bool backup)
3059 {
3060         off_t save_offset = iterator->offset[iterator->depth];
3061         FLAC__ASSERT(0 != *tempfile);
3062
3063         if(0 != fseeko(iterator->file, save_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length, SEEK_SET)) {
3064                 cleanup_tempfile_(tempfile, tempfilename);
3065                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3066                 return false;
3067         }
3068         if(!copy_remaining_bytes_from_file_(iterator->file, *tempfile, &iterator->status)) {
3069                 cleanup_tempfile_(tempfile, tempfilename);
3070                 return false;
3071         }
3072
3073         if(fixup_is_last_code != 0) {
3074                 /*
3075                  * if code == 1, it means a block was appended to the end so
3076                  *   we have to clear the is_last flag of the previous block
3077                  * if code == -1, it means the last block was deleted so
3078                  *   we have to set the is_last flag of the previous block
3079                  */
3080                 /* MAGIC NUMBERs here; we know the is_last flag is the high bit of the byte at this location */
3081                 FLAC__byte x;
3082                 if(0 != fseeko(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
3083                         cleanup_tempfile_(tempfile, tempfilename);
3084                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3085                         return false;
3086                 }
3087                 if(fread(&x, 1, 1, *tempfile) != 1) {
3088                         cleanup_tempfile_(tempfile, tempfilename);
3089                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3090                         return false;
3091                 }
3092                 if(fixup_is_last_code > 0) {
3093                         FLAC__ASSERT(x & 0x80);
3094                         x &= 0x7f;
3095                 }
3096                 else {
3097                         FLAC__ASSERT(!(x & 0x80));
3098                         x |= 0x80;
3099                 }
3100                 if(0 != fseeko(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
3101                         cleanup_tempfile_(tempfile, tempfilename);
3102                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3103                         return false;
3104                 }
3105                 if(local__fwrite(&x, 1, 1, *tempfile) != 1) {
3106                         cleanup_tempfile_(tempfile, tempfilename);
3107                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3108                         return false;
3109                 }
3110         }
3111
3112         (void)fclose(iterator->file);
3113
3114         if(!transport_tempfile_(iterator->filename, tempfile, tempfilename, &iterator->status))
3115                 return false;
3116
3117         if(iterator->has_stats)
3118                 set_file_stats_(iterator->filename, &iterator->stats);
3119
3120         if(!simple_iterator_prime_input_(iterator, !iterator->is_writable))
3121                 return false;
3122         if(backup) {
3123                 while(iterator->offset[iterator->depth] + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length < save_offset)
3124                         if(!FLAC__metadata_simple_iterator_next(iterator))
3125                                 return false;
3126                 return true;
3127         }
3128         else {
3129                 /* move the iterator to it's original block faster by faking a push, then doing a pop_ */
3130                 FLAC__ASSERT(iterator->depth == 0);
3131                 iterator->offset[0] = save_offset;
3132                 iterator->depth++;
3133                 return simple_iterator_pop_(iterator);
3134         }
3135 }
3136
3137 FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status)
3138 {
3139         FLAC__byte buffer[8192];
3140         size_t n;
3141
3142         FLAC__ASSERT(bytes >= 0);
3143         while(bytes > 0) {
3144                 n = min(sizeof(buffer), (size_t)bytes);
3145                 if(fread(buffer, 1, n, file) != n) {
3146                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3147                         return false;
3148                 }
3149                 if(local__fwrite(buffer, 1, n, tempfile) != n) {
3150                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3151                         return false;
3152                 }
3153                 bytes -= n;
3154         }
3155
3156         return true;
3157 }
3158
3159 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, off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status)
3160 {
3161         FLAC__byte buffer[8192];
3162         size_t n;
3163
3164         FLAC__ASSERT(bytes >= 0);
3165         while(bytes > 0) {
3166                 n = min(sizeof(buffer), (size_t)bytes);
3167                 if(read_cb(buffer, 1, n, handle) != n) {
3168                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3169                         return false;
3170                 }
3171                 if(temp_write_cb(buffer, 1, n, temp_handle) != n) {
3172                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3173                         return false;
3174                 }
3175                 bytes -= n;
3176         }
3177
3178         return true;
3179 }
3180
3181 FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status)
3182 {
3183         FLAC__byte buffer[8192];
3184         size_t n;
3185
3186         while(!feof(file)) {
3187                 n = fread(buffer, 1, sizeof(buffer), file);
3188                 if(n == 0 && !feof(file)) {
3189                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3190                         return false;
3191                 }
3192                 if(n > 0 && local__fwrite(buffer, 1, n, tempfile) != n) {
3193                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3194                         return false;
3195                 }
3196         }
3197
3198         return true;
3199 }
3200
3201 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)
3202 {
3203         FLAC__byte buffer[8192];
3204         size_t n;
3205
3206         while(!eof_cb(handle)) {
3207                 n = read_cb(buffer, 1, sizeof(buffer), handle);
3208                 if(n == 0 && !eof_cb(handle)) {
3209                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3210                         return false;
3211                 }
3212                 if(n > 0 && temp_write_cb(buffer, 1, n, temp_handle) != n) {
3213                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3214                         return false;
3215                 }
3216         }
3217
3218         return true;
3219 }
3220
3221 FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
3222 {
3223         static const char *tempfile_suffix = ".metadata_edit";
3224         if(0 == tempfile_path_prefix) {
3225                 if(0 == (*tempfilename = (char*)safe_malloc_add_3op_(strlen(filename), /*+*/strlen(tempfile_suffix), /*+*/1))) {
3226                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
3227                         return false;
3228                 }
3229                 strcpy(*tempfilename, filename);
3230                 strcat(*tempfilename, tempfile_suffix);
3231         }
3232         else {
3233                 const char *p = strrchr(filename, '/');
3234                 if(0 == p)
3235                         p = filename;
3236                 else
3237                         p++;
3238
3239                 if(0 == (*tempfilename = (char*)safe_malloc_add_4op_(strlen(tempfile_path_prefix), /*+*/strlen(p), /*+*/strlen(tempfile_suffix), /*+*/2))) {
3240                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
3241                         return false;
3242                 }
3243                 strcpy(*tempfilename, tempfile_path_prefix);
3244                 strcat(*tempfilename, "/");
3245                 strcat(*tempfilename, p);
3246                 strcat(*tempfilename, tempfile_suffix);
3247         }
3248
3249         if(0 == (*tempfile = fopen(*tempfilename, "w+b"))) {
3250                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
3251                 return false;
3252         }
3253
3254         return true;
3255 }
3256
3257 FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
3258 {
3259         FLAC__ASSERT(0 != filename);
3260         FLAC__ASSERT(0 != tempfile);
3261         FLAC__ASSERT(0 != *tempfile);
3262         FLAC__ASSERT(0 != tempfilename);
3263         FLAC__ASSERT(0 != *tempfilename);
3264         FLAC__ASSERT(0 != status);
3265
3266         (void)fclose(*tempfile);
3267         *tempfile = 0;
3268
3269 #if defined _MSC_VER || defined __BORLANDC__ || defined __MINGW32__ || defined __EMX__
3270         /* on some flavors of windows, rename() will fail if the destination already exists */
3271         if(unlink(filename) < 0) {
3272                 cleanup_tempfile_(tempfile, tempfilename);
3273                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR;
3274                 return false;
3275         }
3276 #endif
3277
3278         /*@@@ to fully support the tempfile_path_prefix we need to update this piece to actually copy across filesystems instead of just rename(): */
3279         if(0 != rename(*tempfilename, filename)) {
3280                 cleanup_tempfile_(tempfile, tempfilename);
3281                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR;
3282                 return false;
3283         }
3284
3285         cleanup_tempfile_(tempfile, tempfilename);
3286
3287         return true;
3288 }
3289
3290 void cleanup_tempfile_(FILE **tempfile, char **tempfilename)
3291 {
3292         if(0 != *tempfile) {
3293                 (void)fclose(*tempfile);
3294                 *tempfile = 0;
3295         }
3296
3297         if(0 != *tempfilename) {
3298                 (void)unlink(*tempfilename);
3299                 free(*tempfilename);
3300                 *tempfilename = 0;
3301         }
3302 }
3303
3304 FLAC__bool get_file_stats_(const char *filename, struct stat *stats)
3305 {
3306         FLAC__ASSERT(0 != filename);
3307         FLAC__ASSERT(0 != stats);
3308         return (0 == stat(filename, stats));
3309 }
3310
3311 void set_file_stats_(const char *filename, struct stat *stats)
3312 {
3313         struct utimbuf srctime;
3314
3315         FLAC__ASSERT(0 != filename);
3316         FLAC__ASSERT(0 != stats);
3317
3318         srctime.actime = stats->st_atime;
3319         srctime.modtime = stats->st_mtime;
3320         (void)chmod(filename, stats->st_mode);
3321         (void)utime(filename, &srctime);
3322 #if !defined _MSC_VER && !defined __BORLANDC__ && !defined __MINGW32__ && !defined __EMX__
3323         (void)chown(filename, stats->st_uid, -1);
3324         (void)chown(filename, -1, stats->st_gid);
3325 #endif
3326 }
3327
3328 int fseek_wrapper_(FLAC__IOHandle handle, FLAC__int64 offset, int whence)
3329 {
3330         return fseeko((FILE*)handle, (off_t)offset, whence);
3331 }
3332
3333 FLAC__int64 ftell_wrapper_(FLAC__IOHandle handle)
3334 {
3335         return ftello((FILE*)handle);
3336 }
3337
3338 FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status)
3339 {
3340         switch(status) {
3341                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK:
3342                         return FLAC__METADATA_CHAIN_STATUS_OK;
3343                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT:
3344                         return FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT;
3345                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE:
3346                         return FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
3347                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE:
3348                         return FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE;
3349                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE:
3350                         return FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE;
3351                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA:
3352                         return FLAC__METADATA_CHAIN_STATUS_BAD_METADATA;
3353                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR:
3354                         return FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
3355                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR:
3356                         return FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
3357                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR:
3358                         return FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
3359                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR:
3360                         return FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR;
3361                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR:
3362                         return FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR;
3363                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR:
3364                         return FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
3365                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR:
3366                 default:
3367                         return FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
3368         }
3369 }