src/libFLAC/metadata_iterators.c

   1 /* libFLAC - Free Lossless Audio Codec library
   2  * Copyright (C) 2001,2002,2003,2004,2005,2006,2007  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 #define fseeko fseek
  51 #define ftello ftell
  52 #endif
  53 #else
  54 #include <sys/types.h> /* some flavors of BSD (like OS X) require this to get time_t */
  55 #include <utime.h> /* for utime() */
  56 #include <unistd.h> /* for chown(), unlink() */
  57 #endif
  58 #include <sys/stat.h> /* for stat(), maybe chmod() */
  59
  60 #include "private/metadata.h"
  61
  62 #include "FLAC/assert.h"
  63 #include "FLAC/stream_decoder.h"
  64 #include "share/alloc.h"
  65
  66 #ifdef max
  67 #undef max
  68 #endif
  69 #define max(a,b) ((a)>(b)?(a):(b))
  70 #ifdef min
  71 #undef min
  72 #endif
  73 #define min(a,b) ((a)<(b)?(a):(b))
  74
  75
  76 /****************************************************************************
  77  *
  78  * Local function declarations
  79  *
  80  ***************************************************************************/
  81
  82 static void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes);
  83 static void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes);
  84 static void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes);
  85 static FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes);
  86 static FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes);
  87 static FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes);
  88
  89 static FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator);
  90 static FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block);
  91 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);
  92 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);
  93 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_StreamInfo *block);
  94 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);
  95 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);
  96 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);
  97 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);
  98 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment *block);
  99 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet_Track *track);
 100 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet *block);
 101 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Picture *block);
 102 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);
 103
 104 static FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block);
 105 static FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block);
 106 static FLAC__bool write_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block);
 107 static FLAC__bool write_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block);
 108 static FLAC__bool write_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_StreamInfo *block);
 109 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);
 110 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);
 111 static FLAC__bool write_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_SeekTable *block);
 112 static FLAC__bool write_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_VorbisComment *block);
 113 static FLAC__bool write_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_CueSheet *block);
 114 static FLAC__bool write_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Picture *block);
 115 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);
 116
 117 static FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block);
 118 static FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last);
 119 static FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append);
 120
 121 static void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator);
 122 static FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator);
 123
 124 static unsigned seek_to_first_metadata_block_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb);
 125 static unsigned seek_to_first_metadata_block_(FILE *f);
 126
 127 static FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append);
 128 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);
 129
 130 static FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status);
 131 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);
 132 static FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status);
 133 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);
 134
 135 static FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status);
 136 static FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status);
 137 static void cleanup_tempfile_(FILE **tempfile, char **tempfilename);
 138
 139 static FLAC__bool get_file_stats_(const char *filename, struct stat *stats);
 140 static void set_file_stats_(const char *filename, struct stat *stats);
 141
 142 static int fseek_wrapper_(FLAC__IOHandle handle, FLAC__int64 offset, int whence);
 143 static FLAC__int64 ftell_wrapper_(FLAC__IOHandle handle);
 144
 145 static FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status);
 146
 147
 148 #ifdef FLAC__VALGRIND_TESTING
 149 static size_t local__fwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream)
 150 {
 151         size_t ret = fwrite(ptr, size, nmemb, stream);
 152         if(!ferror(stream))
 153                 fflush(stream);
 154         return ret;
 155 }
 156 #else
 157 #define local__fwrite fwrite
 158 #endif
 159
 160 /****************************************************************************
 161  *
 162  * Level 0 implementation
 163  *
 164  ***************************************************************************/
 165
 166 static FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data);
 167 static void metadata_callback_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data);
 168 static void error_callback_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data);
 169
 170 typedef struct {
 171         FLAC__bool got_error;
 172         FLAC__StreamMetadata *object;
 173 } level0_client_data;
 174
 175 static FLAC__StreamMetadata *get_one_metadata_block_(const char *filename, FLAC__MetadataType type)
 176 {
 177         level0_client_data cd;
 178         FLAC__StreamDecoder *decoder;
 179
 180         FLAC__ASSERT(0 != filename);
 181
 182         cd.got_error = false;
 183         cd.object = 0;
 184
 185         decoder = FLAC__stream_decoder_new();
 186
 187         if(0 == decoder)
 188                 return 0;
 189
 190         FLAC__stream_decoder_set_md5_checking(decoder, false);
 191         FLAC__stream_decoder_set_metadata_ignore_all(decoder);
 192         FLAC__stream_decoder_set_metadata_respond(decoder, type);
 193
 194         if(FLAC__stream_decoder_init_file(decoder, filename, write_callback_, metadata_callback_, error_callback_, &cd) != FLAC__STREAM_DECODER_INIT_STATUS_OK || cd.got_error) {
 195                 (void)FLAC__stream_decoder_finish(decoder);
 196                 FLAC__stream_decoder_delete(decoder);
 197                 return 0;
 198         }
 199
 200         if(!FLAC__stream_decoder_process_until_end_of_metadata(decoder) || cd.got_error) {
 201                 (void)FLAC__stream_decoder_finish(decoder);
 202                 FLAC__stream_decoder_delete(decoder);
 203                 if(0 != cd.object)
 204                         FLAC__metadata_object_delete(cd.object);
 205                 return 0;
 206         }
 207
 208         (void)FLAC__stream_decoder_finish(decoder);
 209         FLAC__stream_decoder_delete(decoder);
 210
 211         return cd.object;
 212 }
 213
 214 FLAC_API FLAC__bool FLAC__metadata_get_streaminfo(const char *filename, FLAC__StreamMetadata *streaminfo)
 215 {
 216         FLAC__StreamMetadata *object;
 217
 218         FLAC__ASSERT(0 != filename);
 219         FLAC__ASSERT(0 != streaminfo);
 220
 221         object = get_one_metadata_block_(filename, FLAC__METADATA_TYPE_STREAMINFO);
 222
 223         if (object) {
 224                 /* can just copy the contents since STREAMINFO has no internal structure */
 225                 *streaminfo = *object;
 226                 FLAC__metadata_object_delete(object);
 227                 return true;
 228         }
 229         else {
 230                 return false;
 231         }
 232 }
 233
 234 FLAC_API FLAC__bool FLAC__metadata_get_tags(const char *filename, FLAC__StreamMetadata **tags)
 235 {
 236         FLAC__ASSERT(0 != filename);
 237         FLAC__ASSERT(0 != tags);
 238
 239         *tags = get_one_metadata_block_(filename, FLAC__METADATA_TYPE_VORBIS_COMMENT);
 240
 241         return 0 != *tags;
 242 }
 243
 244 FLAC_API FLAC__bool FLAC__metadata_get_cuesheet(const char *filename, FLAC__StreamMetadata **cuesheet)
 245 {
 246         FLAC__ASSERT(0 != filename);
 247         FLAC__ASSERT(0 != cuesheet);
 248
 249         *cuesheet = get_one_metadata_block_(filename, FLAC__METADATA_TYPE_CUESHEET);
 250
 251         return 0 != *cuesheet;
 252 }
 253
 254 FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
 255 {
 256         (void)decoder, (void)frame, (void)buffer, (void)client_data;
 257
 258         return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;
 259 }
 260
 261 void metadata_callback_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
 262 {
 263         level0_client_data *cd = (level0_client_data *)client_data;
 264         (void)decoder;
 265
 266         /*
 267          * we assume we only get here when the one metadata block we were
 268          * looking for was passed to us
 269          */
 270         if(!cd->got_error && 0 == cd->object) {
 271                 if(0 == (cd->object = FLAC__metadata_object_clone(metadata)))
 272                         cd->got_error = true;
 273         }
 274 }
 275
 276 void error_callback_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
 277 {
 278         level0_client_data *cd = (level0_client_data *)client_data;
 279         (void)decoder;
 280
 281         if(status != FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC)
 282                 cd->got_error = true;
 283 }
 284
 285 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)
 286 {
 287         FLAC__Metadata_SimpleIterator *it;
 288         FLAC__uint64 max_area_seen = 0;
 289         FLAC__uint64 max_depth_seen = 0;
 290
 291         FLAC__ASSERT(0 != filename);
 292         FLAC__ASSERT(0 != picture);
 293
 294         *picture = 0;
 295
 296         it = FLAC__metadata_simple_iterator_new();
 297         if(0 == it)
 298                 return false;
 299         if(!FLAC__metadata_simple_iterator_init(it, filename, /*read_only=*/true, /*preserve_file_stats=*/true)) {
 300                 FLAC__metadata_simple_iterator_delete(it);
 301                 return false;
 302         }
 303         do {
 304                 if(FLAC__metadata_simple_iterator_get_block_type(it) == FLAC__METADATA_TYPE_PICTURE) {
 305                         FLAC__StreamMetadata *obj = FLAC__metadata_simple_iterator_get_block(it);
 306                         FLAC__uint64 area = (FLAC__uint64)obj->data.picture.width * (FLAC__uint64)obj->data.picture.height;
 307                         /* check constraints */
 308                         if(
 309                                 (type == (FLAC__StreamMetadata_Picture_Type)(-1) || type == obj->data.picture.type) &&
 310                                 (mime_type == 0 || !strcmp(mime_type, obj->data.picture.mime_type)) &&
 311                                 (description == 0 || !strcmp((const char *)description, (const char *)obj->data.picture.description)) &&
 312                                 obj->data.picture.width <= max_width &&
 313                                 obj->data.picture.height <= max_height &&
 314                                 obj->data.picture.depth <= max_depth &&
 315                                 obj->data.picture.colors <= max_colors &&
 316                                 (area > max_area_seen || (area == max_area_seen && obj->data.picture.depth > max_depth_seen))
 317                         ) {
 318                                 if(*picture)
 319                                         FLAC__metadata_object_delete(*picture);
 320                                 *picture = obj;
 321                                 max_area_seen = area;
 322                                 max_depth_seen = obj->data.picture.depth;
 323                         }
 324                         else {
 325                                 FLAC__metadata_object_delete(obj);
 326                         }
 327                 }
 328         } while(FLAC__metadata_simple_iterator_next(it));
 329
 330         FLAC__metadata_simple_iterator_delete(it);
 331
 332         return (0 != *picture);
 333 }
 334
 335
 336 /****************************************************************************
 337  *
 338  * Level 1 implementation
 339  *
 340  ***************************************************************************/
 341
 342 #define SIMPLE_ITERATOR_MAX_PUSH_DEPTH (1+4)
 343 /* 1 for initial offset, +4 for our own personal use */
 344
 345 struct FLAC__Metadata_SimpleIterator {
 346         FILE *file;
 347         char *filename, *tempfile_path_prefix;
 348         struct stat stats;
 349         FLAC__bool has_stats;
 350         FLAC__bool is_writable;
 351         FLAC__Metadata_SimpleIteratorStatus status;
 352         off_t offset[SIMPLE_ITERATOR_MAX_PUSH_DEPTH];
 353         off_t first_offset; /* this is the offset to the STREAMINFO block */
 354         unsigned depth;
 355         /* this is the metadata block header of the current block we are pointing to: */
 356         FLAC__bool is_last;
 357         FLAC__MetadataType type;
 358         unsigned length;
 359 };
 360
 361 FLAC_API const char * const FLAC__Metadata_SimpleIteratorStatusString[] = {
 362         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK",
 363         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT",
 364         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE",
 365         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE",
 366         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE",
 367         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA",
 368         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR",
 369         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR",
 370         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR",
 371         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR",
 372         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR",
 373         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR",
 374         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR"
 375 };
 376
 377
 378 FLAC_API FLAC__Metadata_SimpleIterator *FLAC__metadata_simple_iterator_new(void)
 379 {
 380         FLAC__Metadata_SimpleIterator *iterator = (FLAC__Metadata_SimpleIterator*)calloc(1, sizeof(FLAC__Metadata_SimpleIterator));
 381
 382         if(0 != iterator) {
 383                 iterator->file = 0;
 384                 iterator->filename = 0;
 385                 iterator->tempfile_path_prefix = 0;
 386                 iterator->has_stats = false;
 387                 iterator->is_writable = false;
 388                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
 389                 iterator->first_offset = iterator->offset[0] = -1;
 390                 iterator->depth = 0;
 391         }
 392
 393         return iterator;
 394 }
 395
 396 static void simple_iterator_free_guts_(FLAC__Metadata_SimpleIterator *iterator)
 397 {
 398         FLAC__ASSERT(0 != iterator);
 399
 400         if(0 != iterator->file) {
 401                 fclose(iterator->file);
 402                 iterator->file = 0;
 403                 if(iterator->has_stats)
 404                         set_file_stats_(iterator->filename, &iterator->stats);
 405         }
 406         if(0 != iterator->filename) {
 407                 free(iterator->filename);
 408                 iterator->filename = 0;
 409         }
 410         if(0 != iterator->tempfile_path_prefix) {
 411                 free(iterator->tempfile_path_prefix);
 412                 iterator->tempfile_path_prefix = 0;
 413         }
 414 }
 415
 416 FLAC_API void FLAC__metadata_simple_iterator_delete(FLAC__Metadata_SimpleIterator *iterator)
 417 {
 418         FLAC__ASSERT(0 != iterator);
 419
 420         simple_iterator_free_guts_(iterator);
 421         free(iterator);
 422 }
 423
 424 FLAC_API FLAC__Metadata_SimpleIteratorStatus FLAC__metadata_simple_iterator_status(FLAC__Metadata_SimpleIterator *iterator)
 425 {
 426         FLAC__Metadata_SimpleIteratorStatus status;
 427
 428         FLAC__ASSERT(0 != iterator);
 429
 430         status = iterator->status;
 431         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
 432         return status;
 433 }
 434
 435 static FLAC__bool simple_iterator_prime_input_(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool read_only)
 436 {
 437         unsigned ret;
 438
 439         FLAC__ASSERT(0 != iterator);
 440
 441         if(read_only || 0 == (iterator->file = fopen(iterator->filename, "r+be"))) {
 442                 iterator->is_writable = false;
 443                 if(read_only || errno == EACCES) {
 444                         if(0 == (iterator->file = fopen(iterator->filename, "rbe"))) {
 445                                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
 446                                 return false;
 447                         }
 448                 }
 449                 else {
 450                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
 451                         return false;
 452                 }
 453         }
 454         else {
 455                 iterator->is_writable = true;
 456         }
 457
 458         ret = seek_to_first_metadata_block_(iterator->file);
 459         switch(ret) {
 460                 case 0:
 461                         iterator->depth = 0;
 462                         iterator->first_offset = iterator->offset[iterator->depth] = ftello(iterator->file);
 463                         return read_metadata_block_header_(iterator);
 464                 case 1:
 465                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
 466                         return false;
 467                 case 2:
 468                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 469                         return false;
 470                 case 3:
 471                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE;
 472                         return false;
 473                 default:
 474                         FLAC__ASSERT(0);
 475                         return false;
 476         }
 477 }
 478
 479 #if 0
 480 @@@ If we decide to finish implementing this, put this comment back in metadata.h
 481 /*
 482  * The 'tempfile_path_prefix' allows you to specify a directory where
 483  * tempfiles should go.  Remember that if your metadata edits cause the
 484  * FLAC file to grow, the entire file will have to be rewritten.  If
 485  * 'tempfile_path_prefix' is NULL, the temp file will be written in the
 486  * same directory as the original FLAC file.  This makes replacing the
 487  * original with the tempfile fast but requires extra space in the same
 488  * partition for the tempfile.  If space is a problem, you can pass a
 489  * directory name belonging to a different partition in
 490  * 'tempfile_path_prefix'.  Note that you should use the forward slash
 491  * '/' as the directory separator.  A trailing slash is not needed; it
 492  * will be added automatically.
 493  */
 494 FLAC__bool FLAC__metadata_simple_iterator_init(FLAC__Metadata_SimpleIterator *iterator, const char *filename, FLAC__bool preserve_file_stats, const char *tempfile_path_prefix);
 495 #endif
 496
 497 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)
 498 {
 499         const char *tempfile_path_prefix = 0; /*@@@ search for comments near 'rename(...)' for what it will take to finish implementing this */
 500
 501         FLAC__ASSERT(0 != iterator);
 502         FLAC__ASSERT(0 != filename);
 503
 504         simple_iterator_free_guts_(iterator);
 505
 506         if(!read_only && preserve_file_stats)
 507                 iterator->has_stats = get_file_stats_(filename, &iterator->stats);
 508
 509         if(0 == (iterator->filename = strdup(filename))) {
 510                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 511                 return false;
 512         }
 513         if(0 != tempfile_path_prefix && 0 == (iterator->tempfile_path_prefix = strdup(tempfile_path_prefix))) {
 514                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 515                 return false;
 516         }
 517
 518         return simple_iterator_prime_input_(iterator, read_only);
 519 }
 520
 521 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_is_writable(const FLAC__Metadata_SimpleIterator *iterator)
 522 {
 523         FLAC__ASSERT(0 != iterator);
 524         FLAC__ASSERT(0 != iterator->file);
 525
 526         return iterator->is_writable;
 527 }
 528
 529 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_next(FLAC__Metadata_SimpleIterator *iterator)
 530 {
 531         FLAC__ASSERT(0 != iterator);
 532         FLAC__ASSERT(0 != iterator->file);
 533
 534         if(iterator->is_last)
 535                 return false;
 536
 537         if(0 != fseeko(iterator->file, iterator->length, SEEK_CUR)) {
 538                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 539                 return false;
 540         }
 541
 542         iterator->offset[iterator->depth] = ftello(iterator->file);
 543
 544         return read_metadata_block_header_(iterator);
 545 }
 546
 547 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_prev(FLAC__Metadata_SimpleIterator *iterator)
 548 {
 549         off_t this_offset;
 550
 551         FLAC__ASSERT(0 != iterator);
 552         FLAC__ASSERT(0 != iterator->file);
 553
 554         if(iterator->offset[iterator->depth] == iterator->first_offset)
 555                 return false;
 556
 557         if(0 != fseeko(iterator->file, iterator->first_offset, SEEK_SET)) {
 558                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 559                 return false;
 560         }
 561         this_offset = iterator->first_offset;
 562         if(!read_metadata_block_header_(iterator))
 563                 return false;
 564
 565         /* we ignore any error from ftello() and catch it in fseeko() */
 566         while(ftello(iterator->file) + (off_t)iterator->length < iterator->offset[iterator->depth]) {
 567                 if(0 != fseeko(iterator->file, iterator->length, SEEK_CUR)) {
 568                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 569                         return false;
 570                 }
 571                 this_offset = ftello(iterator->file);
 572                 if(!read_metadata_block_header_(iterator))
 573                         return false;
 574         }
 575
 576         iterator->offset[iterator->depth] = this_offset;
 577
 578         return true;
 579 }
 580
 581 /*@@@@add to tests*/
 582 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_is_last(const FLAC__Metadata_SimpleIterator *iterator)
 583 {
 584         FLAC__ASSERT(0 != iterator);
 585         FLAC__ASSERT(0 != iterator->file);
 586
 587         return iterator->is_last;
 588 }
 589
 590 /*@@@@add to tests*/
 591 FLAC_API off_t FLAC__metadata_simple_iterator_get_block_offset(const FLAC__Metadata_SimpleIterator *iterator)
 592 {
 593         FLAC__ASSERT(0 != iterator);
 594         FLAC__ASSERT(0 != iterator->file);
 595
 596         return iterator->offset[iterator->depth];
 597 }
 598
 599 FLAC_API FLAC__MetadataType FLAC__metadata_simple_iterator_get_block_type(const FLAC__Metadata_SimpleIterator *iterator)
 600 {
 601         FLAC__ASSERT(0 != iterator);
 602         FLAC__ASSERT(0 != iterator->file);
 603
 604         return iterator->type;
 605 }
 606
 607 /*@@@@add to tests*/
 608 FLAC_API unsigned FLAC__metadata_simple_iterator_get_block_length(const FLAC__Metadata_SimpleIterator *iterator)
 609 {
 610         FLAC__ASSERT(0 != iterator);
 611         FLAC__ASSERT(0 != iterator->file);
 612
 613         return iterator->length;
 614 }
 615
 616 /*@@@@add to tests*/
 617 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_get_application_id(FLAC__Metadata_SimpleIterator *iterator, FLAC__byte *id)
 618 {
 619         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
 620
 621         FLAC__ASSERT(0 != iterator);
 622         FLAC__ASSERT(0 != iterator->file);
 623         FLAC__ASSERT(0 != id);
 624
 625         if(iterator->type != FLAC__METADATA_TYPE_APPLICATION) {
 626                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 627                 return false;
 628         }
 629
 630         if(fread(id, 1, id_bytes, iterator->file) != id_bytes) {
 631                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
 632                 return false;
 633         }
 634
 635         /* back up */
 636         if(0 != fseeko(iterator->file, -((int)id_bytes), SEEK_CUR)) {
 637                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 638                 return false;
 639         }
 640
 641         return true;
 642 }
 643
 644 FLAC_API FLAC__StreamMetadata *FLAC__metadata_simple_iterator_get_block(FLAC__Metadata_SimpleIterator *iterator)
 645 {
 646         FLAC__StreamMetadata *block = FLAC__metadata_object_new(iterator->type);
 647
 648         FLAC__ASSERT(0 != iterator);
 649         FLAC__ASSERT(0 != iterator->file);
 650
 651         if(0 != block) {
 652                 block->is_last = iterator->is_last;
 653                 block->length = iterator->length;
 654
 655                 if(!read_metadata_block_data_(iterator, block)) {
 656                         FLAC__metadata_object_delete(block);
 657                         return 0;
 658                 }
 659
 660                 /* back up to the beginning of the block data to stay consistent */
 661                 if(0 != fseeko(iterator->file, iterator->offset[iterator->depth] + FLAC__STREAM_METADATA_HEADER_LENGTH, SEEK_SET)) {
 662                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 663                         FLAC__metadata_object_delete(block);
 664                         return 0;
 665                 }
 666         }
 667         else
 668                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 669
 670         return block;
 671 }
 672
 673 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_set_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding)
 674 {
 675         FLAC__ASSERT_DECLARATION(off_t debug_target_offset = iterator->offset[iterator->depth];)
 676         FLAC__bool ret;
 677
 678         FLAC__ASSERT(0 != iterator);
 679         FLAC__ASSERT(0 != iterator->file);
 680         FLAC__ASSERT(0 != block);
 681
 682         if(!iterator->is_writable) {
 683                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE;
 684                 return false;
 685         }
 686
 687         if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO || block->type == FLAC__METADATA_TYPE_STREAMINFO) {
 688                 if(iterator->type != block->type) {
 689                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 690                         return false;
 691                 }
 692         }
 693
 694         block->is_last = iterator->is_last;
 695
 696         if(iterator->length == block->length)
 697                 return write_metadata_block_stationary_(iterator, block);
 698         else if(iterator->length > block->length) {
 699                 if(use_padding && iterator->length >= FLAC__STREAM_METADATA_HEADER_LENGTH + block->length) {
 700                         ret = write_metadata_block_stationary_with_padding_(iterator, block, iterator->length - FLAC__STREAM_METADATA_HEADER_LENGTH - block->length, block->is_last);
 701                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 702                         FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 703                         return ret;
 704                 }
 705                 else {
 706                         ret = rewrite_whole_file_(iterator, block, /*append=*/false);
 707                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 708                         FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 709                         return ret;
 710                 }
 711         }
 712         else /* iterator->length < block->length */ {
 713                 unsigned padding_leftover = 0;
 714                 FLAC__bool padding_is_last = false;
 715                 if(use_padding) {
 716                         /* first see if we can even use padding */
 717                         if(iterator->is_last) {
 718                                 use_padding = false;
 719                         }
 720                         else {
 721                                 const unsigned extra_padding_bytes_required = block->length - iterator->length;
 722                                 simple_iterator_push_(iterator);
 723                                 if(!FLAC__metadata_simple_iterator_next(iterator)) {
 724                                         (void)simple_iterator_pop_(iterator);
 725                                         return false;
 726                                 }
 727                                 if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
 728                                         use_padding = false;
 729                                 }
 730                                 else {
 731                                         if(FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length == extra_padding_bytes_required) {
 732                                                 padding_leftover = 0;
 733                                                 block->is_last = iterator->is_last;
 734                                         }
 735                                         else if(iterator->length < extra_padding_bytes_required)
 736                                                 use_padding = false;
 737                                         else {
 738                                                 padding_leftover = FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length - extra_padding_bytes_required;
 739                                                 padding_is_last = iterator->is_last;
 740                                                 block->is_last = false;
 741                                         }
 742                                 }
 743                                 if(!simple_iterator_pop_(iterator))
 744                                         return false;
 745                         }
 746                 }
 747                 if(use_padding) {
 748                         if(padding_leftover == 0) {
 749                                 ret = write_metadata_block_stationary_(iterator, block);
 750                                 FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 751                                 FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 752                                 return ret;
 753                         }
 754                         else {
 755                                 FLAC__ASSERT(padding_leftover >= FLAC__STREAM_METADATA_HEADER_LENGTH);
 756                                 ret = write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover - FLAC__STREAM_METADATA_HEADER_LENGTH, padding_is_last);
 757                                 FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 758                                 FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 759                                 return ret;
 760                         }
 761                 }
 762                 else {
 763                         ret = rewrite_whole_file_(iterator, block, /*append=*/false);
 764                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 765                         FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 766                         return ret;
 767                 }
 768         }
 769 }
 770
 771 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_insert_block_after(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding)
 772 {
 773         unsigned padding_leftover = 0;
 774         FLAC__bool padding_is_last = false;
 775
 776         FLAC__ASSERT_DECLARATION(off_t debug_target_offset = iterator->offset[iterator->depth] + FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length;)
 777         FLAC__bool ret;
 778
 779         FLAC__ASSERT(0 != iterator);
 780         FLAC__ASSERT(0 != iterator->file);
 781         FLAC__ASSERT(0 != block);
 782
 783         if(!iterator->is_writable)
 784                 return false;
 785
 786         if(block->type == FLAC__METADATA_TYPE_STREAMINFO) {
 787                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 788                 return false;
 789         }
 790
 791         block->is_last = iterator->is_last;
 792
 793         if(use_padding) {
 794                 /* first see if we can even use padding */
 795                 if(iterator->is_last) {
 796                         use_padding = false;
 797                 }
 798                 else {
 799                         simple_iterator_push_(iterator);
 800                         if(!FLAC__metadata_simple_iterator_next(iterator)) {
 801                                 (void)simple_iterator_pop_(iterator);
 802                                 return false;
 803                         }
 804                         if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
 805                                 use_padding = false;
 806                         }
 807                         else {
 808                                 if(iterator->length == block->length) {
 809                                         padding_leftover = 0;
 810                                         block->is_last = iterator->is_last;
 811                                 }
 812                                 else if(iterator->length < FLAC__STREAM_METADATA_HEADER_LENGTH + block->length)
 813                                         use_padding = false;
 814                                 else {
 815                                         padding_leftover = iterator->length - block->length;
 816                                         padding_is_last = iterator->is_last;
 817                                         block->is_last = false;
 818                                 }
 819                         }
 820                         if(!simple_iterator_pop_(iterator))
 821                                 return false;
 822                 }
 823         }
 824         if(use_padding) {
 825                 /* move to the next block, which is suitable padding */
 826                 if(!FLAC__metadata_simple_iterator_next(iterator))
 827                         return false;
 828                 if(padding_leftover == 0) {
 829                         ret = write_metadata_block_stationary_(iterator, block);
 830                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 831                         FLAC__ASSERT(ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 832                         return ret;
 833                 }
 834                 else {
 835                         FLAC__ASSERT(padding_leftover >= FLAC__STREAM_METADATA_HEADER_LENGTH);
 836                         ret = write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover - FLAC__STREAM_METADATA_HEADER_LENGTH, padding_is_last);
 837                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 838                         FLAC__ASSERT(ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 839                         return ret;
 840                 }
 841         }
 842         else {
 843                 ret = rewrite_whole_file_(iterator, block, /*append=*/true);
 844                 FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 845                 FLAC__ASSERT(ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 846                 return ret;
 847         }
 848 }
 849
 850 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_delete_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool use_padding)
 851 {
 852         FLAC__ASSERT_DECLARATION(off_t debug_target_offset = iterator->offset[iterator->depth];)
 853         FLAC__bool ret;
 854
 855         if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO) {
 856                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 857                 return false;
 858         }
 859
 860         if(use_padding) {
 861                 FLAC__StreamMetadata *padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING);
 862                 if(0 == padding) {
 863                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 864                         return false;
 865                 }
 866                 padding->length = iterator->length;
 867                 if(!FLAC__metadata_simple_iterator_set_block(iterator, padding, false)) {
 868                         FLAC__metadata_object_delete(padding);
 869                         return false;
 870                 }
 871                 FLAC__metadata_object_delete(padding);
 872                 if(!FLAC__metadata_simple_iterator_prev(iterator))
 873                         return false;
 874                 FLAC__ASSERT(iterator->offset[iterator->depth] + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length == debug_target_offset);
 875                 FLAC__ASSERT(ftello(iterator->file) + (off_t)iterator->length == debug_target_offset);
 876                 return true;
 877         }
 878         else {
 879                 ret = rewrite_whole_file_(iterator, 0, /*append=*/false);
 880                 FLAC__ASSERT(iterator->offset[iterator->depth] + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length == debug_target_offset);
 881                 FLAC__ASSERT(ftello(iterator->file) + (off_t)iterator->length == debug_target_offset);
 882                 return ret;
 883         }
 884 }
 885
 886
 887
 888 /****************************************************************************
 889  *
 890  * Level 2 implementation
 891  *
 892  ***************************************************************************/
 893
 894
 895 typedef struct FLAC__Metadata_Node {
 896         FLAC__StreamMetadata *data;
 897         struct FLAC__Metadata_Node *prev, *next;
 898 } FLAC__Metadata_Node;
 899
 900 struct FLAC__Metadata_Chain {
 901         char *filename; /* will be NULL if using callbacks */
 902         FLAC__bool is_ogg;
 903         FLAC__Metadata_Node *head;
 904         FLAC__Metadata_Node *tail;
 905         unsigned nodes;
 906         FLAC__Metadata_ChainStatus status;
 907         off_t first_offset, last_offset;
 908         /*
 909          * This is the length of the chain initially read from the FLAC file.
 910          * it is used to compare against the current length to decide whether
 911          * or not the whole file has to be rewritten.
 912          */
 913         off_t initial_length;
 914         /* @@@ hacky, these are currently only needed by ogg reader */
 915         FLAC__IOHandle handle;
 916         FLAC__IOCallback_Read read_cb;
 917 };
 918
 919 struct FLAC__Metadata_Iterator {
 920         FLAC__Metadata_Chain *chain;
 921         FLAC__Metadata_Node *current;
 922 };
 923
 924 FLAC_API const char * const FLAC__Metadata_ChainStatusString[] = {
 925         "FLAC__METADATA_CHAIN_STATUS_OK",
 926         "FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT",
 927         "FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE",
 928         "FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE",
 929         "FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE",
 930         "FLAC__METADATA_CHAIN_STATUS_BAD_METADATA",
 931         "FLAC__METADATA_CHAIN_STATUS_READ_ERROR",
 932         "FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR",
 933         "FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR",
 934         "FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR",
 935         "FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR",
 936         "FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR",
 937         "FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR",
 938         "FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS",
 939         "FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH",
 940         "FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL"
 941 };
 942
 943
 944 static FLAC__Metadata_Node *node_new_(void)
 945 {
 946         return (FLAC__Metadata_Node*)calloc(1, sizeof(FLAC__Metadata_Node));
 947 }
 948
 949 static void node_delete_(FLAC__Metadata_Node *node)
 950 {
 951         FLAC__ASSERT(0 != node);
 952         if(0 != node->data)
 953                 FLAC__metadata_object_delete(node->data);
 954         free(node);
 955 }
 956
 957 static void chain_init_(FLAC__Metadata_Chain *chain)
 958 {
 959         FLAC__ASSERT(0 != chain);
 960
 961         chain->filename = 0;
 962         chain->is_ogg = false;
 963         chain->head = chain->tail = 0;
 964         chain->nodes = 0;
 965         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
 966         chain->initial_length = 0;
 967         chain->read_cb = 0;
 968 }
 969
 970 static void chain_clear_(FLAC__Metadata_Chain *chain)
 971 {
 972         FLAC__Metadata_Node *node, *next;
 973
 974         FLAC__ASSERT(0 != chain);
 975
 976         for(node = chain->head; node; ) {
 977                 next = node->next;
 978                 node_delete_(node);
 979                 node = next;
 980         }
 981
 982         if(0 != chain->filename)
 983                 free(chain->filename);
 984
 985         chain_init_(chain);
 986 }
 987
 988 static void chain_append_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 989 {
 990         FLAC__ASSERT(0 != chain);
 991         FLAC__ASSERT(0 != node);
 992         FLAC__ASSERT(0 != node->data);
 993
 994         node->next = node->prev = 0;
 995         node->data->is_last = true;
 996         if(0 != chain->tail)
 997                 chain->tail->data->is_last = false;
 998
 999         if(0 == chain->head)
1000                 chain->head = node;
1001         else {
1002                 FLAC__ASSERT(0 != chain->tail);
1003                 chain->tail->next = node;
1004                 node->prev = chain->tail;
1005         }
1006         chain->tail = node;
1007         chain->nodes++;
1008 }
1009
1010 static void chain_remove_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
1011 {
1012         FLAC__ASSERT(0 != chain);
1013         FLAC__ASSERT(0 != node);
1014
1015         if(node == chain->head)
1016                 chain->head = node->next;
1017         else
1018                 node->prev->next = node->next;
1019
1020         if(node == chain->tail)
1021                 chain->tail = node->prev;
1022         else
1023                 node->next->prev = node->prev;
1024
1025         if(0 != chain->tail)
1026                 chain->tail->data->is_last = true;
1027
1028         chain->nodes--;
1029 }
1030
1031 static void chain_delete_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
1032 {
1033         chain_remove_node_(chain, node);
1034         node_delete_(node);
1035 }
1036
1037 static off_t chain_calculate_length_(FLAC__Metadata_Chain *chain)
1038 {
1039         const FLAC__Metadata_Node *node;
1040         off_t length = 0;
1041         for(node = chain->head; node; node = node->next)
1042                 length += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1043         return length;
1044 }
1045
1046 static void iterator_insert_node_(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Node *node)
1047 {
1048         FLAC__ASSERT(0 != node);
1049         FLAC__ASSERT(0 != node->data);
1050         FLAC__ASSERT(0 != iterator);
1051         FLAC__ASSERT(0 != iterator->current);
1052         FLAC__ASSERT(0 != iterator->chain);
1053         FLAC__ASSERT(0 != iterator->chain->head);
1054         FLAC__ASSERT(0 != iterator->chain->tail);
1055
1056         node->data->is_last = false;
1057
1058         node->prev = iterator->current->prev;
1059         node->next = iterator->current;
1060
1061         if(0 == node->prev)
1062                 iterator->chain->head = node;
1063         else
1064                 node->prev->next = node;
1065
1066         iterator->current->prev = node;
1067
1068         iterator->chain->nodes++;
1069 }
1070
1071 static void iterator_insert_node_after_(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Node *node)
1072 {
1073         FLAC__ASSERT(0 != node);
1074         FLAC__ASSERT(0 != node->data);
1075         FLAC__ASSERT(0 != iterator);
1076         FLAC__ASSERT(0 != iterator->current);
1077         FLAC__ASSERT(0 != iterator->chain);
1078         FLAC__ASSERT(0 != iterator->chain->head);
1079         FLAC__ASSERT(0 != iterator->chain->tail);
1080
1081         iterator->current->data->is_last = false;
1082
1083         node->prev = iterator->current;
1084         node->next = iterator->current->next;
1085
1086         if(0 == node->next)
1087                 iterator->chain->tail = node;
1088         else
1089                 node->next->prev = node;
1090
1091         node->prev->next = node;
1092
1093         iterator->chain->tail->data->is_last = true;
1094
1095         iterator->chain->nodes++;
1096 }
1097
1098 /* return true iff node and node->next are both padding */
1099 static FLAC__bool chain_merge_adjacent_padding_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
1100 {
1101         if(node->data->type == FLAC__METADATA_TYPE_PADDING && 0 != node->next && node->next->data->type == FLAC__METADATA_TYPE_PADDING) {
1102                 const unsigned growth = FLAC__STREAM_METADATA_HEADER_LENGTH + node->next->data->length;
1103                 node->data->length += growth;
1104
1105                 chain_delete_node_(chain, node->next);
1106                 return true;
1107         }
1108         else
1109                 return false;
1110 }
1111
1112 /* Returns the new length of the chain, or 0 if there was an error. */
1113 /* WATCHOUT: This can get called multiple times before a write, so
1114  * it should still work when this happens.
1115  */
1116 /* WATCHOUT: Make sure to also update the logic in
1117  * FLAC__metadata_chain_check_if_tempfile_needed() if the logic here changes.
1118  */
1119 static off_t chain_prepare_for_write_(FLAC__Metadata_Chain *chain, FLAC__bool use_padding)
1120 {
1121         off_t current_length = chain_calculate_length_(chain);
1122
1123         if(use_padding) {
1124                 /* if the metadata shrank and the last block is padding, we just extend the last padding block */
1125                 if(current_length < chain->initial_length && chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1126                         const off_t delta = chain->initial_length - current_length;
1127                         chain->tail->data->length += delta;
1128                         current_length += delta;
1129                         FLAC__ASSERT(current_length == chain->initial_length);
1130                 }
1131                 /* if the metadata shrank more than 4 bytes then there's room to add another padding block */
1132                 else if(current_length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH <= chain->initial_length) {
1133                         FLAC__StreamMetadata *padding;
1134                         FLAC__Metadata_Node *node;
1135                         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING))) {
1136                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1137                                 return 0;
1138                         }
1139                         padding->length = chain->initial_length - (FLAC__STREAM_METADATA_HEADER_LENGTH + current_length);
1140                         if(0 == (node = node_new_())) {
1141                                 FLAC__metadata_object_delete(padding);
1142                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1143                                 return 0;
1144                         }
1145                         node->data = padding;
1146                         chain_append_node_(chain, node);
1147                         current_length = chain_calculate_length_(chain);
1148                         FLAC__ASSERT(current_length == chain->initial_length);
1149                 }
1150                 /* 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 */
1151                 else if(current_length > chain->initial_length) {
1152                         const off_t delta = current_length - chain->initial_length;
1153                         if(chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1154                                 /* if the delta is exactly the size of the last padding block, remove the padding block */
1155                                 if((off_t)chain->tail->data->length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH == delta) {
1156                                         chain_delete_node_(chain, chain->tail);
1157                                         current_length = chain_calculate_length_(chain);
1158                                         FLAC__ASSERT(current_length == chain->initial_length);
1159                                 }
1160                                 /* if there is at least 'delta' bytes of padding, trim the padding down */
1161                                 else if((off_t)chain->tail->data->length >= delta) {
1162                                         chain->tail->data->length -= delta;
1163                                         current_length -= delta;
1164                                         FLAC__ASSERT(current_length == chain->initial_length);
1165                                 }
1166                         }
1167                 }
1168         }
1169
1170         return current_length;
1171 }
1172
1173 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)
1174 {
1175         FLAC__Metadata_Node *node;
1176
1177         FLAC__ASSERT(0 != chain);
1178
1179         /* we assume we're already at the beginning of the file */
1180
1181         switch(seek_to_first_metadata_block_cb_(handle, read_cb, seek_cb)) {
1182                 case 0:
1183                         break;
1184                 case 1:
1185                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1186                         return false;
1187                 case 2:
1188                         chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1189                         return false;
1190                 case 3:
1191                         chain->status = FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE;
1192                         return false;
1193                 default:
1194                         FLAC__ASSERT(0);
1195                         return false;
1196         }
1197
1198         {
1199                 FLAC__int64 pos = tell_cb(handle);
1200                 if(pos < 0) {
1201                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1202                         return false;
1203                 }
1204                 chain->first_offset = (off_t)pos;
1205         }
1206
1207         {
1208                 FLAC__bool is_last;
1209                 FLAC__MetadataType type;
1210                 unsigned length;
1211
1212                 do {
1213                         node = node_new_();
1214                         if(0 == node) {
1215                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1216                                 return false;
1217                         }
1218
1219                         if(!read_metadata_block_header_cb_(handle, read_cb, &is_last, &type, &length)) {
1220                 node_delete_(node);
1221                                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1222                                 return false;
1223                         }
1224
1225                         node->data = FLAC__metadata_object_new(type);
1226                         if(0 == node->data) {
1227                                 node_delete_(node);
1228                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1229                                 return false;
1230                         }
1231
1232                         node->data->is_last = is_last;
1233                         node->data->length = length;
1234
1235                         chain->status = get_equivalent_status_(read_metadata_block_data_cb_(handle, read_cb, seek_cb, node->data));
1236                         if(chain->status != FLAC__METADATA_CHAIN_STATUS_OK) {
1237                                 node_delete_(node);
1238                                 return false;
1239                         }
1240                         chain_append_node_(chain, node);
1241                 } while(!is_last);
1242         }
1243
1244         {
1245                 FLAC__int64 pos = tell_cb(handle);
1246                 if(pos < 0) {
1247                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1248                         return false;
1249                 }
1250                 chain->last_offset = (off_t)pos;
1251         }
1252
1253         chain->initial_length = chain_calculate_length_(chain);
1254
1255         return true;
1256 }
1257
1258 static FLAC__StreamDecoderReadStatus chain_read_ogg_read_cb_(const FLAC__StreamDecoder *decoder, FLAC__byte buffer[], size_t *bytes, void *client_data)
1259 {
1260         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1261         (void)decoder;
1262         if(*bytes > 0 && chain->status == FLAC__METADATA_CHAIN_STATUS_OK) {
1263                 *bytes = chain->read_cb(buffer, sizeof(FLAC__byte), *bytes, chain->handle);
1264                 if(*bytes == 0)
1265                         return FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM;
1266                 else
1267                         return FLAC__STREAM_DECODER_READ_STATUS_CONTINUE;
1268         }
1269         else
1270                 return FLAC__STREAM_DECODER_READ_STATUS_ABORT;
1271 }
1272
1273 static FLAC__StreamDecoderWriteStatus chain_read_ogg_write_cb_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
1274 {
1275         (void)decoder, (void)frame, (void)buffer, (void)client_data;
1276         return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
1277 }
1278
1279 static void chain_read_ogg_metadata_cb_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
1280 {
1281         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1282         FLAC__Metadata_Node *node;
1283
1284         (void)decoder;
1285
1286         node = node_new_();
1287         if(0 == node) {
1288                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1289                 return;
1290         }
1291
1292         node->data = FLAC__metadata_object_clone(metadata);
1293         if(0 == node->data) {
1294                 node_delete_(node);
1295                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1296                 return;
1297         }
1298
1299         chain_append_node_(chain, node);
1300 }
1301
1302 static void chain_read_ogg_error_cb_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
1303 {
1304         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1305         (void)decoder, (void)status;
1306         chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1307 }
1308
1309 static FLAC__bool chain_read_ogg_cb_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb)
1310 {
1311         FLAC__StreamDecoder *decoder;
1312
1313         FLAC__ASSERT(0 != chain);
1314
1315         /* we assume we're already at the beginning of the file */
1316
1317         chain->handle = handle;
1318         chain->read_cb = read_cb;
1319         if(0 == (decoder = FLAC__stream_decoder_new())) {
1320                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1321                 return false;
1322         }
1323         FLAC__stream_decoder_set_metadata_respond_all(decoder);
1324         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) {
1325                 FLAC__stream_decoder_delete(decoder);
1326                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1327                 return false;
1328         }
1329
1330         chain->first_offset = 0; /*@@@ wrong; will need to be set correctly to implement metadata writing for Ogg FLAC */
1331
1332         if(!FLAC__stream_decoder_process_until_end_of_metadata(decoder))
1333                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1334         if(chain->status != FLAC__METADATA_CHAIN_STATUS_OK) {
1335                 FLAC__stream_decoder_delete(decoder);
1336                 return false;
1337         }
1338
1339         FLAC__stream_decoder_delete(decoder);
1340
1341         chain->last_offset = 0; /*@@@ wrong; will need to be set correctly to implement metadata writing for Ogg FLAC */
1342
1343         chain->initial_length = chain_calculate_length_(chain);
1344
1345         return true;
1346 }
1347
1348 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)
1349 {
1350         FLAC__Metadata_Node *node;
1351
1352         FLAC__ASSERT(0 != chain);
1353         FLAC__ASSERT(0 != chain->head);
1354
1355         if(0 != seek_cb(handle, chain->first_offset, SEEK_SET)) {
1356                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1357                 return false;
1358         }
1359
1360         for(node = chain->head; node; node = node->next) {
1361                 if(!write_metadata_block_header_cb_(handle, write_cb, node->data)) {
1362                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1363                         return false;
1364                 }
1365                 if(!write_metadata_block_data_cb_(handle, write_cb, node->data)) {
1366                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1367                         return false;
1368                 }
1369         }
1370
1371         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1372
1373         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
1374         return true;
1375 }
1376
1377 static FLAC__bool chain_rewrite_metadata_in_place_(FLAC__Metadata_Chain *chain)
1378 {
1379         FILE *file;
1380         FLAC__bool ret;
1381
1382         FLAC__ASSERT(0 != chain->filename);
1383
1384         if(0 == (file = fopen(chain->filename, "r+be"))) {
1385                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1386                 return false;
1387         }
1388
1389         /* chain_rewrite_metadata_in_place_cb_() sets chain->status for us */
1390         ret = chain_rewrite_metadata_in_place_cb_(chain, (FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, fseek_wrapper_);
1391
1392         fclose(file);
1393
1394         return ret;
1395 }
1396
1397 static FLAC__bool chain_rewrite_file_(FLAC__Metadata_Chain *chain, const char *tempfile_path_prefix)
1398 {
1399         FILE *f, *tempfile;
1400         char *tempfilename;
1401         FLAC__Metadata_SimpleIteratorStatus status;
1402         const FLAC__Metadata_Node *node;
1403
1404         FLAC__ASSERT(0 != chain);
1405         FLAC__ASSERT(0 != chain->filename);
1406         FLAC__ASSERT(0 != chain->head);
1407
1408         /* copy the file prefix (data up to first metadata block */
1409         if(0 == (f = fopen(chain->filename, "rbe"))) {
1410                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1411                 return false;
1412         }
1413         if(!open_tempfile_(chain->filename, tempfile_path_prefix, &tempfile, &tempfilename, &status)) {
1414                 chain->status = get_equivalent_status_(status);
1415                 cleanup_tempfile_(&tempfile, &tempfilename);
1416         fclose(f);
1417                 return false;
1418         }
1419         if(!copy_n_bytes_from_file_(f, tempfile, chain->first_offset, &status)) {
1420                 chain->status = get_equivalent_status_(status);
1421                 cleanup_tempfile_(&tempfile, &tempfilename);
1422         fclose(f);
1423                 return false;
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             cleanup_tempfile_(&tempfile, &tempfilename);
1431             fclose(f);
1432                         return false;
1433                 }
1434                 if(!write_metadata_block_data_(tempfile, &status, node->data)) {
1435                         chain->status = get_equivalent_status_(status);
1436             cleanup_tempfile_(&tempfile, &tempfilename);
1437             fclose(f);
1438                         return false;
1439                 }
1440         }
1441         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1442
1443         /* copy the file postfix (everything after the metadata) */
1444         if(0 != fseeko(f, chain->last_offset, SEEK_SET)) {
1445                 cleanup_tempfile_(&tempfile, &tempfilename);
1446                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1447         fclose(f);
1448                 return false;
1449         }
1450         if(!copy_remaining_bytes_from_file_(f, tempfile, &status)) {
1451                 cleanup_tempfile_(&tempfile, &tempfilename);
1452         fclose(f);
1453                 chain->status = get_equivalent_status_(status);
1454                 return false;
1455         }
1456
1457         /* move the tempfile on top of the original */
1458         (void)fclose(f);
1459         if(!transport_tempfile_(chain->filename, &tempfile, &tempfilename, &status))
1460                 return false;
1461
1462         return true;
1463 }
1464
1465 /* assumes 'handle' is already at beginning of file */
1466 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)
1467 {
1468         FLAC__Metadata_SimpleIteratorStatus status;
1469         const FLAC__Metadata_Node *node;
1470
1471         FLAC__ASSERT(0 != chain);
1472         FLAC__ASSERT(0 == chain->filename);
1473         FLAC__ASSERT(0 != chain->head);
1474
1475         /* copy the file prefix (data up to first metadata block */
1476         if(!copy_n_bytes_from_file_cb_(handle, read_cb, temp_handle, temp_write_cb, chain->first_offset, &status)) {
1477                 chain->status = get_equivalent_status_(status);
1478                 return false;
1479         }
1480
1481         /* write the metadata */
1482         for(node = chain->head; node; node = node->next) {
1483                 if(!write_metadata_block_header_cb_(temp_handle, temp_write_cb, node->data)) {
1484                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1485                         return false;
1486                 }
1487                 if(!write_metadata_block_data_cb_(temp_handle, temp_write_cb, node->data)) {
1488                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1489                         return false;
1490                 }
1491         }
1492         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1493
1494         /* copy the file postfix (everything after the metadata) */
1495         if(0 != seek_cb(handle, chain->last_offset, SEEK_SET)) {
1496                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1497                 return false;
1498         }
1499         if(!copy_remaining_bytes_from_file_cb_(handle, read_cb, eof_cb, temp_handle, temp_write_cb, &status)) {
1500                 chain->status = get_equivalent_status_(status);
1501                 return false;
1502         }
1503
1504         return true;
1505 }
1506
1507 FLAC_API FLAC__Metadata_Chain *FLAC__metadata_chain_new(void)
1508 {
1509         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)calloc(1, sizeof(FLAC__Metadata_Chain));
1510
1511         if(0 != chain)
1512                 chain_init_(chain);
1513
1514         return chain;
1515 }
1516
1517 FLAC_API void FLAC__metadata_chain_delete(FLAC__Metadata_Chain *chain)
1518 {
1519         FLAC__ASSERT(0 != chain);
1520
1521         chain_clear_(chain);
1522
1523         free(chain);
1524 }
1525
1526 FLAC_API FLAC__Metadata_ChainStatus FLAC__metadata_chain_status(FLAC__Metadata_Chain *chain)
1527 {
1528         FLAC__Metadata_ChainStatus status;
1529
1530         FLAC__ASSERT(0 != chain);
1531
1532         status = chain->status;
1533         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
1534         return status;
1535 }
1536
1537 static FLAC__bool chain_read_(FLAC__Metadata_Chain *chain, const char *filename, FLAC__bool is_ogg)
1538 {
1539         FILE *file;
1540         FLAC__bool ret;
1541
1542         FLAC__ASSERT(0 != chain);
1543         FLAC__ASSERT(0 != filename);
1544
1545         chain_clear_(chain);
1546
1547         if(0 == (chain->filename = strdup(filename))) {
1548                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1549                 return false;
1550         }
1551
1552         chain->is_ogg = is_ogg;
1553
1554         if(0 == (file = fopen(filename, "rbe"))) {
1555                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1556                 return false;
1557         }
1558
1559         /* the function also sets chain->status for us */
1560         ret = is_ogg?
1561                 chain_read_ogg_cb_(chain, file, (FLAC__IOCallback_Read)fread) :
1562                 chain_read_cb_(chain, file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, ftell_wrapper_)
1563         ;
1564
1565         fclose(file);
1566
1567         return ret;
1568 }
1569
1570 FLAC_API FLAC__bool FLAC__metadata_chain_read(FLAC__Metadata_Chain *chain, const char *filename)
1571 {
1572         return chain_read_(chain, filename, /*is_ogg=*/false);
1573 }
1574
1575 /*@@@@add to tests*/
1576 FLAC_API FLAC__bool FLAC__metadata_chain_read_ogg(FLAC__Metadata_Chain *chain, const char *filename)
1577 {
1578         return chain_read_(chain, filename, /*is_ogg=*/true);
1579 }
1580
1581 static FLAC__bool chain_read_with_callbacks_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks, FLAC__bool is_ogg)
1582 {
1583         FLAC__bool ret;
1584
1585         FLAC__ASSERT(0 != chain);
1586
1587         chain_clear_(chain);
1588
1589         if (0 == callbacks.read || 0 == callbacks.seek || 0 == callbacks.tell) {
1590                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1591                 return false;
1592         }
1593
1594         chain->is_ogg = is_ogg;
1595
1596         /* rewind */
1597         if(0 != callbacks.seek(handle, 0, SEEK_SET)) {
1598                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1599                 return false;
1600         }
1601
1602         /* the function also sets chain->status for us */
1603         ret = is_ogg?
1604                 chain_read_ogg_cb_(chain, handle, callbacks.read) :
1605                 chain_read_cb_(chain, handle, callbacks.read, callbacks.seek, callbacks.tell)
1606         ;
1607
1608         return ret;
1609 }
1610
1611 FLAC_API FLAC__bool FLAC__metadata_chain_read_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1612 {
1613         return chain_read_with_callbacks_(chain, handle, callbacks, /*is_ogg=*/false);
1614 }
1615
1616 /*@@@@add to tests*/
1617 FLAC_API FLAC__bool FLAC__metadata_chain_read_ogg_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1618 {
1619         return chain_read_with_callbacks_(chain, handle, callbacks, /*is_ogg=*/true);
1620 }
1621
1622 FLAC_API FLAC__bool FLAC__metadata_chain_check_if_tempfile_needed(FLAC__Metadata_Chain *chain, FLAC__bool use_padding)
1623 {
1624         /* This does all the same checks that are in chain_prepare_for_write_()
1625          * but doesn't actually alter the chain.  Make sure to update the logic
1626          * here if chain_prepare_for_write_() changes.
1627          */
1628         const off_t current_length = chain_calculate_length_(chain);
1629
1630         FLAC__ASSERT(0 != chain);
1631
1632         if(use_padding) {
1633                 /* if the metadata shrank and the last block is padding, we just extend the last padding block */
1634                 if(current_length < chain->initial_length && chain->tail->data->type == FLAC__METADATA_TYPE_PADDING)
1635                         return false;
1636                 /* if the metadata shrank more than 4 bytes then there's room to add another padding block */
1637                 else if(current_length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH <= chain->initial_length)
1638                         return false;
1639                 /* 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 */
1640                 else if(current_length > chain->initial_length) {
1641                         const off_t delta = current_length - chain->initial_length;
1642                         if(chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1643                                 /* if the delta is exactly the size of the last padding block, remove the padding block */
1644                                 if((off_t)chain->tail->data->length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH == delta)
1645                                         return false;
1646                                 /* if there is at least 'delta' bytes of padding, trim the padding down */
1647                                 else if((off_t)chain->tail->data->length >= delta)
1648                                         return false;
1649                         }
1650                 }
1651         }
1652
1653         return (current_length != chain->initial_length);
1654 }
1655
1656 FLAC_API FLAC__bool FLAC__metadata_chain_write(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__bool preserve_file_stats)
1657 {
1658         struct stat stats;
1659         const char *tempfile_path_prefix = 0;
1660         off_t current_length;
1661
1662         FLAC__ASSERT(0 != chain);
1663
1664         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1665                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1666                 return false;
1667         }
1668
1669         if (0 == chain->filename) {
1670                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1671                 return false;
1672         }
1673
1674         current_length = chain_prepare_for_write_(chain, use_padding);
1675
1676         /* a return value of 0 means there was an error; chain->status is already set */
1677         if (0 == current_length)
1678                 return false;
1679
1680         if(preserve_file_stats)
1681                 get_file_stats_(chain->filename, &stats);
1682
1683         if(current_length == chain->initial_length) {
1684                 if(!chain_rewrite_metadata_in_place_(chain))
1685                         return false;
1686         }
1687         else {
1688                 if(!chain_rewrite_file_(chain, tempfile_path_prefix))
1689                         return false;
1690
1691                 /* recompute lengths and offsets */
1692                 {
1693                         const FLAC__Metadata_Node *node;
1694                         chain->initial_length = current_length;
1695                         chain->last_offset = chain->first_offset;
1696                         for(node = chain->head; node; node = node->next)
1697                                 chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1698                 }
1699         }
1700
1701         if(preserve_file_stats)
1702                 set_file_stats_(chain->filename, &stats);
1703
1704         return true;
1705 }
1706
1707 FLAC_API FLAC__bool FLAC__metadata_chain_write_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1708 {
1709         off_t current_length;
1710
1711         FLAC__ASSERT(0 != chain);
1712
1713         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1714                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1715                 return false;
1716         }
1717
1718         if (0 != chain->filename) {
1719                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1720                 return false;
1721         }
1722
1723         if (0 == callbacks.write || 0 == callbacks.seek) {
1724                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1725                 return false;
1726         }
1727
1728         if (FLAC__metadata_chain_check_if_tempfile_needed(chain, use_padding)) {
1729                 chain->status = FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL;
1730                 return false;
1731         }
1732
1733         current_length = chain_prepare_for_write_(chain, use_padding);
1734
1735         /* a return value of 0 means there was an error; chain->status is already set */
1736         if (0 == current_length)
1737                 return false;
1738
1739         FLAC__ASSERT(current_length == chain->initial_length);
1740
1741         return chain_rewrite_metadata_in_place_cb_(chain, handle, callbacks.write, callbacks.seek);
1742 }
1743
1744 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)
1745 {
1746         off_t current_length;
1747
1748         FLAC__ASSERT(0 != chain);
1749
1750         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1751                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1752                 return false;
1753         }
1754
1755         if (0 != chain->filename) {
1756                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1757                 return false;
1758         }
1759
1760         if (0 == callbacks.read || 0 == callbacks.seek || 0 == callbacks.eof) {
1761                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1762                 return false;
1763         }
1764         if (0 == temp_callbacks.write) {
1765                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1766                 return false;
1767         }
1768
1769         if (!FLAC__metadata_chain_check_if_tempfile_needed(chain, use_padding)) {
1770                 chain->status = FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL;
1771                 return false;
1772         }
1773
1774         current_length = chain_prepare_for_write_(chain, use_padding);
1775
1776         /* a return value of 0 means there was an error; chain->status is already set */
1777         if (0 == current_length)
1778                 return false;
1779
1780         FLAC__ASSERT(current_length != chain->initial_length);
1781
1782         /* rewind */
1783         if(0 != callbacks.seek(handle, 0, SEEK_SET)) {
1784                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1785                 return false;
1786         }
1787
1788         if(!chain_rewrite_file_cb_(chain, handle, callbacks.read, callbacks.seek, callbacks.eof, temp_handle, temp_callbacks.write))
1789                 return false;
1790
1791         /* recompute lengths and offsets */
1792         {
1793                 const FLAC__Metadata_Node *node;
1794                 chain->initial_length = current_length;
1795                 chain->last_offset = chain->first_offset;
1796                 for(node = chain->head; node; node = node->next)
1797                         chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1798         }
1799
1800         return true;
1801 }
1802
1803 FLAC_API void FLAC__metadata_chain_merge_padding(FLAC__Metadata_Chain *chain)
1804 {
1805         FLAC__Metadata_Node *node;
1806
1807         FLAC__ASSERT(0 != chain);
1808
1809         for(node = chain->head; node; ) {
1810                 if(!chain_merge_adjacent_padding_(chain, node))
1811                         node = node->next;
1812         }
1813 }
1814
1815 FLAC_API void FLAC__metadata_chain_sort_padding(FLAC__Metadata_Chain *chain)
1816 {
1817         FLAC__Metadata_Node *node, *save;
1818         unsigned i;
1819
1820         FLAC__ASSERT(0 != chain);
1821
1822         /*
1823          * Don't try and be too smart... this simple algo is good enough for
1824          * the small number of nodes that we deal with.
1825          */
1826         for(i = 0, node = chain->head; i < chain->nodes; i++) {
1827                 if(node->data->type == FLAC__METADATA_TYPE_PADDING) {
1828                         save = node->next;
1829                         chain_remove_node_(chain, node);
1830                         chain_append_node_(chain, node);
1831                         node = save;
1832                 }
1833                 else {
1834                         node = node->next;
1835                 }
1836         }
1837
1838         FLAC__metadata_chain_merge_padding(chain);
1839 }
1840
1841
1842 FLAC_API FLAC__Metadata_Iterator *FLAC__metadata_iterator_new(void)
1843 {
1844         FLAC__Metadata_Iterator *iterator = (FLAC__Metadata_Iterator*)calloc(1, sizeof(FLAC__Metadata_Iterator));
1845
1846         /* calloc() implies:
1847                 iterator->current = 0;
1848                 iterator->chain = 0;
1849         */
1850
1851         return iterator;
1852 }
1853
1854 FLAC_API void FLAC__metadata_iterator_delete(FLAC__Metadata_Iterator *iterator)
1855 {
1856         FLAC__ASSERT(0 != iterator);
1857
1858         free(iterator);
1859 }
1860
1861 FLAC_API void FLAC__metadata_iterator_init(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Chain *chain)
1862 {
1863         FLAC__ASSERT(0 != iterator);
1864         FLAC__ASSERT(0 != chain);
1865         FLAC__ASSERT(0 != chain->head);
1866
1867         iterator->chain = chain;
1868         iterator->current = chain->head;
1869 }
1870
1871 FLAC_API FLAC__bool FLAC__metadata_iterator_next(FLAC__Metadata_Iterator *iterator)
1872 {
1873         FLAC__ASSERT(0 != iterator);
1874
1875         if(0 == iterator->current || 0 == iterator->current->next)
1876                 return false;
1877
1878         iterator->current = iterator->current->next;
1879         return true;
1880 }
1881
1882 FLAC_API FLAC__bool FLAC__metadata_iterator_prev(FLAC__Metadata_Iterator *iterator)
1883 {
1884         FLAC__ASSERT(0 != iterator);
1885
1886         if(0 == iterator->current || 0 == iterator->current->prev)
1887                 return false;
1888
1889         iterator->current = iterator->current->prev;
1890         return true;
1891 }
1892
1893 FLAC_API FLAC__MetadataType FLAC__metadata_iterator_get_block_type(const FLAC__Metadata_Iterator *iterator)
1894 {
1895         FLAC__ASSERT(0 != iterator);
1896         FLAC__ASSERT(0 != iterator->current);
1897         FLAC__ASSERT(0 != iterator->current->data);
1898
1899         return iterator->current->data->type;
1900 }
1901
1902 FLAC_API FLAC__StreamMetadata *FLAC__metadata_iterator_get_block(FLAC__Metadata_Iterator *iterator)
1903 {
1904         FLAC__ASSERT(0 != iterator);
1905         FLAC__ASSERT(0 != iterator->current);
1906
1907         return iterator->current->data;
1908 }
1909
1910 FLAC_API FLAC__bool FLAC__metadata_iterator_set_block(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1911 {
1912         FLAC__ASSERT(0 != iterator);
1913         FLAC__ASSERT(0 != block);
1914         return FLAC__metadata_iterator_delete_block(iterator, false) && FLAC__metadata_iterator_insert_block_after(iterator, block);
1915 }
1916
1917 FLAC_API FLAC__bool FLAC__metadata_iterator_delete_block(FLAC__Metadata_Iterator *iterator, FLAC__bool replace_with_padding)
1918 {
1919         FLAC__Metadata_Node *save;
1920
1921         FLAC__ASSERT(0 != iterator);
1922         FLAC__ASSERT(0 != iterator->current);
1923
1924         if(0 == iterator->current->prev) {
1925                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1926                 return false;
1927         }
1928
1929         save = iterator->current->prev;
1930
1931         if(replace_with_padding) {
1932                 FLAC__metadata_object_delete_data(iterator->current->data);
1933                 iterator->current->data->type = FLAC__METADATA_TYPE_PADDING;
1934         }
1935         else {
1936                 chain_delete_node_(iterator->chain, iterator->current);
1937         }
1938
1939         iterator->current = save;
1940         return true;
1941 }
1942
1943 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_before(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1944 {
1945         FLAC__Metadata_Node *node;
1946
1947         FLAC__ASSERT(0 != iterator);
1948         FLAC__ASSERT(0 != iterator->current);
1949         FLAC__ASSERT(0 != block);
1950
1951         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1952                 return false;
1953
1954         if(0 == iterator->current->prev) {
1955                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1956                 return false;
1957         }
1958
1959         if(0 == (node = node_new_()))
1960                 return false;
1961
1962         node->data = block;
1963         iterator_insert_node_(iterator, node);
1964         iterator->current = node;
1965         return true;
1966 }
1967
1968 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_after(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1969 {
1970         FLAC__Metadata_Node *node;
1971
1972         FLAC__ASSERT(0 != iterator);
1973         FLAC__ASSERT(0 != iterator->current);
1974         FLAC__ASSERT(0 != block);
1975
1976         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1977                 return false;
1978
1979         if(0 == (node = node_new_()))
1980                 return false;
1981
1982         node->data = block;
1983         iterator_insert_node_after_(iterator, node);
1984         iterator->current = node;
1985         return true;
1986 }
1987
1988
1989 /****************************************************************************
1990  *
1991  * Local function definitions
1992  *
1993  ***************************************************************************/
1994
1995 void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
1996 {
1997         unsigned i;
1998
1999         b += bytes;
2000
2001         for(i = 0; i < bytes; i++) {
2002                 *(--b) = (FLAC__byte)(val & 0xff);
2003                 val >>= 8;
2004         }
2005 }
2006
2007 void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
2008 {
2009         unsigned i;
2010
2011         for(i = 0; i < bytes; i++) {
2012                 *(b++) = (FLAC__byte)(val & 0xff);
2013                 val >>= 8;
2014         }
2015 }
2016
2017 void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes)
2018 {
2019         unsigned i;
2020
2021         b += bytes;
2022
2023         for(i = 0; i < bytes; i++) {
2024                 *(--b) = (FLAC__byte)(val & 0xff);
2025                 val >>= 8;
2026         }
2027 }
2028
2029 FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes)
2030 {
2031         FLAC__uint32 ret = 0;
2032         unsigned i;
2033
2034         for(i = 0; i < bytes; i++)
2035                 ret = (ret << 8) | (FLAC__uint32)(*b++);
2036
2037         return ret;
2038 }
2039
2040 FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes)
2041 {
2042         FLAC__uint32 ret = 0;
2043         unsigned i;
2044
2045         b += bytes;
2046
2047         for(i = 0; i < bytes; i++)
2048                 ret = (ret << 8) | (FLAC__uint32)(*--b);
2049
2050         return ret;
2051 }
2052
2053 FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes)
2054 {
2055         FLAC__uint64 ret = 0;
2056         unsigned i;
2057
2058         for(i = 0; i < bytes; i++)
2059                 ret = (ret << 8) | (FLAC__uint64)(*b++);
2060
2061         return ret;
2062 }
2063
2064 FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator)
2065 {
2066         FLAC__ASSERT(0 != iterator);
2067         FLAC__ASSERT(0 != iterator->file);
2068
2069         if(!read_metadata_block_header_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, &iterator->is_last, &iterator->type, &iterator->length)) {
2070                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2071                 return false;
2072         }
2073
2074         return true;
2075 }
2076
2077 FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block)
2078 {
2079         FLAC__ASSERT(0 != iterator);
2080         FLAC__ASSERT(0 != iterator->file);
2081
2082         iterator->status = read_metadata_block_data_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, block);
2083
2084         return (iterator->status == FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK);
2085 }
2086
2087 FLAC__bool read_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__bool *is_last, FLAC__MetadataType *type, unsigned *length)
2088 {
2089         FLAC__byte raw_header[FLAC__STREAM_METADATA_HEADER_LENGTH];
2090
2091         if(read_cb(raw_header, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
2092                 return false;
2093
2094         *is_last = raw_header[0] & 0x80? true : false;
2095         *type = (FLAC__MetadataType)(raw_header[0] & 0x7f);
2096         *length = unpack_uint32_(raw_header + 1, 3);
2097
2098         /* Note that we don't check:
2099          *    if(iterator->type >= FLAC__METADATA_TYPE_UNDEFINED)
2100          * we just will read in an opaque block
2101          */
2102
2103         return true;
2104 }
2105
2106 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata *block)
2107 {
2108         switch(block->type) {
2109                 case FLAC__METADATA_TYPE_STREAMINFO:
2110                         return read_metadata_block_data_streaminfo_cb_(handle, read_cb, &block->data.stream_info);
2111                 case FLAC__METADATA_TYPE_PADDING:
2112                         return read_metadata_block_data_padding_cb_(handle, seek_cb, &block->data.padding, block->length);
2113                 case FLAC__METADATA_TYPE_APPLICATION:
2114                         return read_metadata_block_data_application_cb_(handle, read_cb, &block->data.application, block->length);
2115                 case FLAC__METADATA_TYPE_SEEKTABLE:
2116                         return read_metadata_block_data_seektable_cb_(handle, read_cb, &block->data.seek_table, block->length);
2117                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
2118                         return read_metadata_block_data_vorbis_comment_cb_(handle, read_cb, &block->data.vorbis_comment);
2119                 case FLAC__METADATA_TYPE_CUESHEET:
2120                         return read_metadata_block_data_cuesheet_cb_(handle, read_cb, &block->data.cue_sheet);
2121                 case FLAC__METADATA_TYPE_PICTURE:
2122                         return read_metadata_block_data_picture_cb_(handle, read_cb, &block->data.picture);
2123                 default:
2124                         return read_metadata_block_data_unknown_cb_(handle, read_cb, &block->data.unknown, block->length);
2125         }
2126 }
2127
2128 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_StreamInfo *block)
2129 {
2130         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH], *b;
2131
2132         if(read_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
2133                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2134
2135         b = buffer;
2136
2137         /* we are using hardcoded numbers for simplicity but we should
2138          * probably eventually write a bit-level unpacker and use the
2139          * _STREAMINFO_ constants.
2140          */
2141         block->min_blocksize = unpack_uint32_(b, 2); b += 2;
2142         block->max_blocksize = unpack_uint32_(b, 2); b += 2;
2143         block->min_framesize = unpack_uint32_(b, 3); b += 3;
2144         block->max_framesize = unpack_uint32_(b, 3); b += 3;
2145         block->sample_rate = (unpack_uint32_(b, 2) << 4) | ((unsigned)(b[2] & 0xf0) >> 4);
2146         block->channels = (unsigned)((b[2] & 0x0e) >> 1) + 1;
2147         block->bits_per_sample = ((((unsigned)(b[2] & 0x01)) << 4) | (((unsigned)(b[3] & 0xf0)) >> 4)) + 1;
2148         block->total_samples = (((FLAC__uint64)(b[3] & 0x0f)) << 32) | unpack_uint64_(b+4, 4);
2149         memcpy(block->md5sum, b+8, 16);
2150
2151         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2152 }
2153
2154 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata_Padding *block, unsigned block_length)
2155 {
2156         (void)block; /* nothing to do; we don't care about reading the padding bytes */
2157
2158         if(0 != seek_cb(handle, block_length, SEEK_CUR))
2159                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2160
2161         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2162 }
2163
2164 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Application *block, unsigned block_length)
2165 {
2166         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
2167
2168         if(read_cb(block->id, 1, id_bytes, handle) != id_bytes)
2169                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2170
2171         if(block_length < id_bytes)
2172                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2173
2174         block_length -= id_bytes;
2175
2176         if(block_length == 0) {
2177                 block->data = 0;
2178         }
2179         else {
2180                 if(0 == (block->data = (FLAC__byte*)malloc(block_length)))
2181                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2182
2183                 if(read_cb(block->data, 1, block_length, handle) != block_length)
2184                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2185         }
2186
2187         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2188 }
2189
2190 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_SeekTable *block, unsigned block_length)
2191 {
2192         unsigned i;
2193         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
2194
2195         FLAC__ASSERT(block_length % FLAC__STREAM_METADATA_SEEKPOINT_LENGTH == 0);
2196
2197         block->num_points = block_length / FLAC__STREAM_METADATA_SEEKPOINT_LENGTH;
2198
2199         if(block->num_points == 0)
2200                 block->points = 0;
2201         else if(0 == (block->points = (FLAC__StreamMetadata_SeekPoint*)safe_malloc_mul_2op_(block->num_points, /*times*/sizeof(FLAC__StreamMetadata_SeekPoint))))
2202                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2203
2204         for(i = 0; i < block->num_points; i++) {
2205                 if(read_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
2206                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2207                 /* some MAGIC NUMBERs here */
2208                 block->points[i].sample_number = unpack_uint64_(buffer, 8);
2209                 block->points[i].stream_offset = unpack_uint64_(buffer+8, 8);
2210                 block->points[i].frame_samples = unpack_uint32_(buffer+16, 2);
2211         }
2212
2213         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2214 }
2215
2216 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_entry_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment_Entry *entry)
2217 {
2218         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
2219         FLAC__byte buffer[4]; /* magic number is asserted below */
2220
2221         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8 == sizeof(buffer));
2222
2223         if(read_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2224                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2225         entry->length = unpack_uint32_little_endian_(buffer, entry_length_len);
2226
2227         if(0 != entry->entry)
2228                 free(entry->entry);
2229
2230         if(entry->length == 0) {
2231                 entry->entry = 0;
2232         }
2233         else {
2234                 if(0 == (entry->entry = (FLAC__byte*)safe_malloc_add_2op_(entry->length, /*+*/1)))
2235                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2236
2237                 if(read_cb(entry->entry, 1, entry->length, handle) != entry->length)
2238                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2239
2240                 entry->entry[entry->length] = '\0';
2241         }
2242
2243         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2244 }
2245
2246 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment *block)
2247 {
2248         unsigned i;
2249         FLAC__Metadata_SimpleIteratorStatus status;
2250         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2251         FLAC__byte buffer[4]; /* magic number is asserted below */
2252
2253         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8 == sizeof(buffer));
2254
2255         if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, &(block->vendor_string))))
2256                 return status;
2257
2258         if(read_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2259                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2260         block->num_comments = unpack_uint32_little_endian_(buffer, num_comments_len);
2261
2262         if(block->num_comments == 0) {
2263                 block->comments = 0;
2264         }
2265         else if(0 == (block->comments = (FLAC__StreamMetadata_VorbisComment_Entry*)calloc(block->num_comments, sizeof(FLAC__StreamMetadata_VorbisComment_Entry))))
2266                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2267
2268         for(i = 0; i < block->num_comments; i++) {
2269                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, block->comments + i)))
2270                         return status;
2271         }
2272
2273         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2274 }
2275
2276 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet_Track *track)
2277 {
2278         unsigned i, len;
2279         FLAC__byte buffer[32]; /* asserted below that this is big enough */
2280
2281         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2282         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2283         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);
2284
2285         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2286         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2287         if(read_cb(buffer, 1, len, handle) != len)
2288                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2289         track->offset = unpack_uint64_(buffer, len);
2290
2291         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2292         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2293         if(read_cb(buffer, 1, len, handle) != len)
2294                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2295         track->number = (FLAC__byte)unpack_uint32_(buffer, len);
2296
2297         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2298         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2299         if(read_cb(track->isrc, 1, len, handle) != len)
2300                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2301
2302         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);
2303         len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2304         if(read_cb(buffer, 1, len, handle) != len)
2305                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2306         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN == 1);
2307         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN == 1);
2308         track->type = buffer[0] >> 7;
2309         track->pre_emphasis = (buffer[0] >> 6) & 1;
2310
2311         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2312         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2313         if(read_cb(buffer, 1, len, handle) != len)
2314                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2315         track->num_indices = (FLAC__byte)unpack_uint32_(buffer, len);
2316
2317         if(track->num_indices == 0) {
2318                 track->indices = 0;
2319         }
2320         else if(0 == (track->indices = (FLAC__StreamMetadata_CueSheet_Index*)calloc(track->num_indices, sizeof(FLAC__StreamMetadata_CueSheet_Index))))
2321                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2322
2323         for(i = 0; i < track->num_indices; i++) {
2324                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2325                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2326                 if(read_cb(buffer, 1, len, handle) != len)
2327                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2328                 track->indices[i].offset = unpack_uint64_(buffer, len);
2329
2330                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2331                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2332                 if(read_cb(buffer, 1, len, handle) != len)
2333                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2334                 track->indices[i].number = (FLAC__byte)unpack_uint32_(buffer, len);
2335
2336                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2337                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2338                 if(read_cb(buffer, 1, len, handle) != len)
2339                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2340         }
2341
2342         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2343 }
2344
2345 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet *block)
2346 {
2347         unsigned i, len;
2348         FLAC__Metadata_SimpleIteratorStatus status;
2349         FLAC__byte buffer[1024]; /* MSVC needs a constant expression so we put a magic number and assert */
2350
2351         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN)/8 <= sizeof(buffer));
2352         FLAC__ASSERT(sizeof(FLAC__uint64) <= sizeof(buffer));
2353
2354         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2355         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2356         if(read_cb(block->media_catalog_number, 1, len, handle) != len)
2357                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2358
2359         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2360         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2361         if(read_cb(buffer, 1, len, handle) != len)
2362                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2363         block->lead_in = unpack_uint64_(buffer, len);
2364
2365         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2366         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2367         if(read_cb(buffer, 1, len, handle) != len)
2368                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2369         block->is_cd = buffer[0]&0x80? true : false;
2370
2371         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2372         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2373         if(read_cb(buffer, 1, len, handle) != len)
2374                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2375         block->num_tracks = unpack_uint32_(buffer, len);
2376
2377         if(block->num_tracks == 0) {
2378                 block->tracks = 0;
2379         }
2380         else if(0 == (block->tracks = (FLAC__StreamMetadata_CueSheet_Track*)calloc(block->num_tracks, sizeof(FLAC__StreamMetadata_CueSheet_Track))))
2381                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2382
2383         for(i = 0; i < block->num_tracks; i++) {
2384                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_cuesheet_track_cb_(handle, read_cb, block->tracks + i)))
2385                         return status;
2386         }
2387
2388         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2389 }
2390
2391 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)
2392 {
2393         FLAC__byte buffer[sizeof(FLAC__uint32)];
2394
2395         FLAC__ASSERT(0 != data);
2396         FLAC__ASSERT(length_len%8 == 0);
2397
2398         length_len /= 8; /* convert to bytes */
2399
2400         FLAC__ASSERT(sizeof(buffer) >= length_len);
2401
2402         if(read_cb(buffer, 1, length_len, handle) != length_len)
2403                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2404         *length = unpack_uint32_(buffer, length_len);
2405
2406         if(0 != *data)
2407                 free(*data);
2408
2409         if(0 == (*data = (FLAC__byte*)safe_malloc_add_2op_(*length, /*+*/1)))
2410                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2411
2412         if(*length > 0) {
2413                 if(read_cb(*data, 1, *length, handle) != *length)
2414                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2415         }
2416
2417         (*data)[*length] = '\0';
2418
2419         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2420 }
2421
2422 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Picture *block)
2423 {
2424         FLAC__Metadata_SimpleIteratorStatus status;
2425         FLAC__byte buffer[4]; /* asserted below that this is big enough */
2426         FLAC__uint32 len;
2427
2428         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8);
2429         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8);
2430         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8);
2431         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8);
2432         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8);
2433
2434         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_TYPE_LEN % 8 == 0);
2435         len = FLAC__STREAM_METADATA_PICTURE_TYPE_LEN / 8;
2436         if(read_cb(buffer, 1, len, handle) != len)
2437                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2438         block->type = (FLAC__StreamMetadata_Picture_Type)unpack_uint32_(buffer, len);
2439
2440         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)
2441                 return status;
2442
2443         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)
2444                 return status;
2445
2446         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN % 8 == 0);
2447         len = FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN / 8;
2448         if(read_cb(buffer, 1, len, handle) != len)
2449                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2450         block->width = unpack_uint32_(buffer, len);
2451
2452         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN % 8 == 0);
2453         len = FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN / 8;
2454         if(read_cb(buffer, 1, len, handle) != len)
2455                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2456         block->height = unpack_uint32_(buffer, len);
2457
2458         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN % 8 == 0);
2459         len = FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN / 8;
2460         if(read_cb(buffer, 1, len, handle) != len)
2461                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2462         block->depth = unpack_uint32_(buffer, len);
2463
2464         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_COLORS_LEN % 8 == 0);
2465         len = FLAC__STREAM_METADATA_PICTURE_COLORS_LEN / 8;
2466         if(read_cb(buffer, 1, len, handle) != len)
2467                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2468         block->colors = unpack_uint32_(buffer, len);
2469
2470         /* for convenience we use read_metadata_block_data_picture_cstring_cb_() even though it adds an extra terminating NUL we don't use */
2471         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)
2472                 return status;
2473
2474         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2475 }
2476
2477 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2478 {
2479         if(block_length == 0) {
2480                 block->data = 0;
2481         }
2482         else {
2483                 if(0 == (block->data = (FLAC__byte*)malloc(block_length)))
2484                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2485
2486                 if(read_cb(block->data, 1, block_length, handle) != block_length)
2487                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2488         }
2489
2490         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2491 }
2492
2493 FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2494 {
2495         FLAC__ASSERT(0 != file);
2496         FLAC__ASSERT(0 != status);
2497
2498         if(!write_metadata_block_header_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2499                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2500                 return false;
2501         }
2502
2503         return true;
2504 }
2505
2506 FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2507 {
2508         FLAC__ASSERT(0 != file);
2509         FLAC__ASSERT(0 != status);
2510
2511         if (write_metadata_block_data_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2512                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2513                 return true;
2514         }
2515         else {
2516                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2517                 return false;
2518         }
2519 }
2520
2521 FLAC__bool write_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2522 {
2523         FLAC__byte buffer[FLAC__STREAM_METADATA_HEADER_LENGTH];
2524
2525         FLAC__ASSERT(block->length < (1u << FLAC__STREAM_METADATA_LENGTH_LEN));
2526
2527         buffer[0] = (block->is_last? 0x80 : 0) | (FLAC__byte)block->type;
2528         pack_uint32_(block->length, buffer + 1, 3);
2529
2530         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
2531                 return false;
2532
2533         return true;
2534 }
2535
2536 FLAC__bool write_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2537 {
2538         FLAC__ASSERT(0 != block);
2539
2540         switch(block->type) {
2541                 case FLAC__METADATA_TYPE_STREAMINFO:
2542                         return write_metadata_block_data_streaminfo_cb_(handle, write_cb, &block->data.stream_info);
2543                 case FLAC__METADATA_TYPE_PADDING:
2544                         return write_metadata_block_data_padding_cb_(handle, write_cb, &block->data.padding, block->length);
2545                 case FLAC__METADATA_TYPE_APPLICATION:
2546                         return write_metadata_block_data_application_cb_(handle, write_cb, &block->data.application, block->length);
2547                 case FLAC__METADATA_TYPE_SEEKTABLE:
2548                         return write_metadata_block_data_seektable_cb_(handle, write_cb, &block->data.seek_table);
2549                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
2550                         return write_metadata_block_data_vorbis_comment_cb_(handle, write_cb, &block->data.vorbis_comment);
2551                 case FLAC__METADATA_TYPE_CUESHEET:
2552                         return write_metadata_block_data_cuesheet_cb_(handle, write_cb, &block->data.cue_sheet);
2553                 case FLAC__METADATA_TYPE_PICTURE:
2554                         return write_metadata_block_data_picture_cb_(handle, write_cb, &block->data.picture);
2555                 default:
2556                         return write_metadata_block_data_unknown_cb_(handle, write_cb, &block->data.unknown, block->length);
2557         }
2558 }
2559
2560 FLAC__bool write_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_StreamInfo *block)
2561 {
2562         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH];
2563         const unsigned channels1 = block->channels - 1;
2564         const unsigned bps1 = block->bits_per_sample - 1;
2565
2566         /* we are using hardcoded numbers for simplicity but we should
2567          * probably eventually write a bit-level packer and use the
2568          * _STREAMINFO_ constants.
2569          */
2570         pack_uint32_(block->min_blocksize, buffer, 2);
2571         pack_uint32_(block->max_blocksize, buffer+2, 2);
2572         pack_uint32_(block->min_framesize, buffer+4, 3);
2573         pack_uint32_(block->max_framesize, buffer+7, 3);
2574         buffer[10] = (block->sample_rate >> 12) & 0xff;
2575         buffer[11] = (block->sample_rate >> 4) & 0xff;
2576         buffer[12] = ((block->sample_rate & 0x0f) << 4) | (channels1 << 1) | (bps1 >> 4);
2577         buffer[13] = (FLAC__byte)(((bps1 & 0x0f) << 4) | ((block->total_samples >> 32) & 0x0f));
2578         pack_uint32_((FLAC__uint32)block->total_samples, buffer+14, 4);
2579         memcpy(buffer+18, block->md5sum, 16);
2580
2581         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
2582                 return false;
2583
2584         return true;
2585 }
2586
2587 FLAC__bool write_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Padding *block, unsigned block_length)
2588 {
2589         unsigned i, n = block_length;
2590         FLAC__byte buffer[1024];
2591
2592         (void)block;
2593
2594         memset(buffer, 0, 1024);
2595
2596         for(i = 0; i < n/1024; i++)
2597                 if(write_cb(buffer, 1, 1024, handle) != 1024)
2598                         return false;
2599
2600         n %= 1024;
2601
2602         if(write_cb(buffer, 1, n, handle) != n)
2603                 return false;
2604
2605         return true;
2606 }
2607
2608 FLAC__bool write_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Application *block, unsigned block_length)
2609 {
2610         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
2611
2612         if(write_cb(block->id, 1, id_bytes, handle) != id_bytes)
2613                 return false;
2614
2615         block_length -= id_bytes;
2616
2617         if(write_cb(block->data, 1, block_length, handle) != block_length)
2618                 return false;
2619
2620         return true;
2621 }
2622
2623 FLAC__bool write_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_SeekTable *block)
2624 {
2625         unsigned i;
2626         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
2627
2628         for(i = 0; i < block->num_points; i++) {
2629                 /* some MAGIC NUMBERs here */
2630                 pack_uint64_(block->points[i].sample_number, buffer, 8);
2631                 pack_uint64_(block->points[i].stream_offset, buffer+8, 8);
2632                 pack_uint32_(block->points[i].frame_samples, buffer+16, 2);
2633                 if(write_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
2634                         return false;
2635         }
2636
2637         return true;
2638 }
2639
2640 FLAC__bool write_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_VorbisComment *block)
2641 {
2642         unsigned i;
2643         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
2644         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2645         FLAC__byte buffer[4]; /* magic number is asserted below */
2646
2647         FLAC__ASSERT(max(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN, FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN) / 8 == sizeof(buffer));
2648
2649         pack_uint32_little_endian_(block->vendor_string.length, buffer, entry_length_len);
2650         if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2651                 return false;
2652         if(write_cb(block->vendor_string.entry, 1, block->vendor_string.length, handle) != block->vendor_string.length)
2653                 return false;
2654
2655         pack_uint32_little_endian_(block->num_comments, buffer, num_comments_len);
2656         if(write_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2657                 return false;
2658
2659         for(i = 0; i < block->num_comments; i++) {
2660                 pack_uint32_little_endian_(block->comments[i].length, buffer, entry_length_len);
2661                 if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2662                         return false;
2663                 if(write_cb(block->comments[i].entry, 1, block->comments[i].length, handle) != block->comments[i].length)
2664                         return false;
2665         }
2666
2667         return true;
2668 }
2669
2670 FLAC__bool write_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_CueSheet *block)
2671 {
2672         unsigned i, j, len;
2673         FLAC__byte buffer[1024]; /* asserted below that this is big enough */
2674
2675         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2676         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN/8);
2677         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);
2678         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2679
2680         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2681         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2682         if(write_cb(block->media_catalog_number, 1, len, handle) != len)
2683                 return false;
2684
2685         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2686         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2687         pack_uint64_(block->lead_in, buffer, len);
2688         if(write_cb(buffer, 1, len, handle) != len)
2689                 return false;
2690
2691         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2692         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2693         memset(buffer, 0, len);
2694         if(block->is_cd)
2695                 buffer[0] |= 0x80;
2696         if(write_cb(buffer, 1, len, handle) != len)
2697                 return false;
2698
2699         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2700         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2701         pack_uint32_(block->num_tracks, buffer, len);
2702         if(write_cb(buffer, 1, len, handle) != len)
2703                 return false;
2704
2705         for(i = 0; i < block->num_tracks; i++) {
2706                 FLAC__StreamMetadata_CueSheet_Track *track = block->tracks + i;
2707
2708                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2709                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2710                 pack_uint64_(track->offset, buffer, len);
2711                 if(write_cb(buffer, 1, len, handle) != len)
2712                         return false;
2713
2714                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2715                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2716                 pack_uint32_(track->number, buffer, len);
2717                 if(write_cb(buffer, 1, len, handle) != len)
2718                         return false;
2719
2720                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2721                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2722                 if(write_cb(track->isrc, 1, len, handle) != len)
2723                         return false;
2724
2725                 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);
2726                 len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2727                 memset(buffer, 0, len);
2728                 buffer[0] = (track->type << 7) | (track->pre_emphasis << 6);
2729                 if(write_cb(buffer, 1, len, handle) != len)
2730                         return false;
2731
2732                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2733                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2734                 pack_uint32_(track->num_indices, buffer, len);
2735                 if(write_cb(buffer, 1, len, handle) != len)
2736                         return false;
2737
2738                 for(j = 0; j < track->num_indices; j++) {
2739                         FLAC__StreamMetadata_CueSheet_Index *index = track->indices + j;
2740
2741                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2742                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2743                         pack_uint64_(index->offset, buffer, len);
2744                         if(write_cb(buffer, 1, len, handle) != len)
2745                                 return false;
2746
2747                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2748                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2749                         pack_uint32_(index->number, buffer, len);
2750                         if(write_cb(buffer, 1, len, handle) != len)
2751                                 return false;
2752
2753                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2754                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2755                         memset(buffer, 0, len);
2756                         if(write_cb(buffer, 1, len, handle) != len)
2757                                 return false;
2758                 }
2759         }
2760
2761         return true;
2762 }
2763
2764 FLAC__bool write_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Picture *block)
2765 {
2766         unsigned len;
2767         size_t slen;
2768         FLAC__byte buffer[4]; /* magic number is asserted below */
2769
2770         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_TYPE_LEN%8);
2771         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN%8);
2772         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN%8);
2773         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN%8);
2774         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN%8);
2775         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN%8);
2776         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_COLORS_LEN%8);
2777         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN%8);
2778         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8);
2779         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN/8);
2780         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN/8);
2781         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8);
2782         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8);
2783         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8);
2784         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8);
2785         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN/8);
2786
2787         len = FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8;
2788         pack_uint32_(block->type, buffer, len);
2789         if(write_cb(buffer, 1, len, handle) != len)
2790                 return false;
2791
2792         len = FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN/8;
2793         slen = strlen(block->mime_type);
2794         pack_uint32_(slen, buffer, len);
2795         if(write_cb(buffer, 1, len, handle) != len)
2796                 return false;
2797         if(write_cb(block->mime_type, 1, slen, handle) != slen)
2798                 return false;
2799
2800         len = FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN/8;
2801         slen = strlen((const char *)block->description);
2802         pack_uint32_(slen, buffer, len);
2803         if(write_cb(buffer, 1, len, handle) != len)
2804                 return false;
2805         if(write_cb(block->description, 1, slen, handle) != slen)
2806                 return false;
2807
2808         len = FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8;
2809         pack_uint32_(block->width, buffer, len);
2810         if(write_cb(buffer, 1, len, handle) != len)
2811                 return false;
2812
2813         len = FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8;
2814         pack_uint32_(block->height, buffer, len);
2815         if(write_cb(buffer, 1, len, handle) != len)
2816                 return false;
2817
2818         len = FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8;
2819         pack_uint32_(block->depth, buffer, len);
2820         if(write_cb(buffer, 1, len, handle) != len)
2821                 return false;
2822
2823         len = FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8;
2824         pack_uint32_(block->colors, buffer, len);
2825         if(write_cb(buffer, 1, len, handle) != len)
2826                 return false;
2827
2828         len = FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN/8;
2829         pack_uint32_(block->data_length, buffer, len);
2830         if(write_cb(buffer, 1, len, handle) != len)
2831                 return false;
2832         if(write_cb(block->data, 1, block->data_length, handle) != block->data_length)
2833                 return false;
2834
2835         return true;
2836 }
2837
2838 FLAC__bool write_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2839 {
2840         if(write_cb(block->data, 1, block_length, handle) != block_length)
2841                 return false;
2842
2843         return true;
2844 }
2845
2846 FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block)
2847 {
2848         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2849                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2850                 return false;
2851         }
2852
2853         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2854                 return false;
2855
2856         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2857                 return false;
2858
2859         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2860                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2861                 return false;
2862         }
2863
2864         return read_metadata_block_header_(iterator);
2865 }
2866
2867 FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last)
2868 {
2869         FLAC__StreamMetadata *padding;
2870
2871         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2872                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2873                 return false;
2874         }
2875
2876         block->is_last = false;
2877
2878         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2879                 return false;
2880
2881         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2882                 return false;
2883
2884         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING)))
2885                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2886
2887         padding->is_last = padding_is_last;
2888         padding->length = padding_length;
2889
2890         if(!write_metadata_block_header_(iterator->file, &iterator->status, padding)) {
2891                 FLAC__metadata_object_delete(padding);
2892                 return false;
2893         }
2894
2895         if(!write_metadata_block_data_(iterator->file, &iterator->status, padding)) {
2896                 FLAC__metadata_object_delete(padding);
2897                 return false;
2898         }
2899
2900         FLAC__metadata_object_delete(padding);
2901
2902         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2903                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2904                 return false;
2905         }
2906
2907         return read_metadata_block_header_(iterator);
2908 }
2909
2910 FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append)
2911 {
2912         FILE *tempfile;
2913         char *tempfilename;
2914         int fixup_is_last_code = 0; /* 0 => no need to change any is_last flags */
2915         off_t fixup_is_last_flag_offset = -1;
2916
2917         FLAC__ASSERT(0 != block || append == false);
2918
2919         if(iterator->is_last) {
2920                 if(append) {
2921                         fixup_is_last_code = 1; /* 1 => clear the is_last flag at the following offset */
2922                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2923                 }
2924                 else if(0 == block) {
2925                         simple_iterator_push_(iterator);
2926                         if(!FLAC__metadata_simple_iterator_prev(iterator)) {
2927                                 (void)simple_iterator_pop_(iterator);
2928                                 return false;
2929                         }
2930                         fixup_is_last_code = -1; /* -1 => set the is_last the flag at the following offset */
2931                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2932                         if(!simple_iterator_pop_(iterator))
2933                                 return false;
2934                 }
2935         }
2936
2937         if(!simple_iterator_copy_file_prefix_(iterator, &tempfile, &tempfilename, append))
2938                 return false;
2939
2940         if(0 != block) {
2941                 if(!write_metadata_block_header_(tempfile, &iterator->status, block)) {
2942                         cleanup_tempfile_(&tempfile, &tempfilename);
2943                         return false;
2944                 }
2945
2946                 if(!write_metadata_block_data_(tempfile, &iterator->status, block)) {
2947                         cleanup_tempfile_(&tempfile, &tempfilename);
2948                         return false;
2949                 }
2950         }
2951
2952         if(!simple_iterator_copy_file_postfix_(iterator, &tempfile, &tempfilename, fixup_is_last_code, fixup_is_last_flag_offset, block==0))
2953                 return false;
2954
2955         if(append)
2956                 return FLAC__metadata_simple_iterator_next(iterator);
2957
2958         return true;
2959 }
2960
2961 void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator)
2962 {
2963         FLAC__ASSERT(iterator->depth+1 < SIMPLE_ITERATOR_MAX_PUSH_DEPTH);
2964         iterator->offset[iterator->depth+1] = iterator->offset[iterator->depth];
2965         iterator->depth++;
2966 }
2967
2968 FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator)
2969 {
2970         FLAC__ASSERT(iterator->depth > 0);
2971         iterator->depth--;
2972         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2973                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2974                 return false;
2975         }
2976
2977         return read_metadata_block_header_(iterator);
2978 }
2979
2980 /* return meanings:
2981  * 0: ok
2982  * 1: read error
2983  * 2: seek error
2984  * 3: not a FLAC file
2985  */
2986 unsigned seek_to_first_metadata_block_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb)
2987 {
2988         FLAC__byte buffer[4];
2989         size_t n;
2990         unsigned i;
2991
2992         FLAC__ASSERT(FLAC__STREAM_SYNC_LENGTH == sizeof(buffer));
2993
2994         /* skip any id3v2 tag */
2995         errno = 0;
2996         n = read_cb(buffer, 1, 4, handle);
2997         if(errno)
2998                 return 1;
2999         else if(n != 4)
3000                 return 3;
3001         else if(0 == memcmp(buffer, "ID3", 3)) {
3002                 unsigned tag_length = 0;
3003
3004                 /* skip to the tag length */
3005                 if(seek_cb(handle, 2, SEEK_CUR) < 0)
3006                         return 2;
3007
3008                 /* read the length */
3009                 for(i = 0; i < 4; i++) {
3010                         if(read_cb(buffer, 1, 1, handle) < 1 || buffer[0] & 0x80)
3011                                 return 1;
3012                         tag_length <<= 7;
3013                         tag_length |= (buffer[0] & 0x7f);
3014                 }
3015
3016                 /* skip the rest of the tag */
3017                 if(seek_cb(handle, tag_length, SEEK_CUR) < 0)
3018                         return 2;
3019
3020                 /* read the stream sync code */
3021                 errno = 0;
3022                 n = read_cb(buffer, 1, 4, handle);
3023                 if(errno)
3024                         return 1;
3025                 else if(n != 4)
3026                         return 3;
3027         }
3028
3029         /* check for the fLaC signature */
3030         if(0 == memcmp(FLAC__STREAM_SYNC_STRING, buffer, FLAC__STREAM_SYNC_LENGTH))
3031                 return 0;
3032         else
3033                 return 3;
3034 }
3035
3036 unsigned seek_to_first_metadata_block_(FILE *f)
3037 {
3038         return seek_to_first_metadata_block_cb_((FLAC__IOHandle)f, (FLAC__IOCallback_Read)fread, fseek_wrapper_);
3039 }
3040
3041 FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append)
3042 {
3043         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];
3044
3045         if(0 != fseeko(iterator->file, 0, SEEK_SET)) {
3046                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3047                 return false;
3048         }
3049         if(!open_tempfile_(iterator->filename, iterator->tempfile_path_prefix, tempfile, tempfilename, &iterator->status)) {
3050                 cleanup_tempfile_(tempfile, tempfilename);
3051                 return false;
3052         }
3053         if(!copy_n_bytes_from_file_(iterator->file, *tempfile, offset_end, &iterator->status)) {
3054                 cleanup_tempfile_(tempfile, tempfilename);
3055                 return false;
3056         }
3057
3058         return true;
3059 }
3060
3061 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)
3062 {
3063         off_t save_offset = iterator->offset[iterator->depth];
3064         FLAC__ASSERT(0 != *tempfile);
3065
3066         if(0 != fseeko(iterator->file, save_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length, SEEK_SET)) {
3067                 cleanup_tempfile_(tempfile, tempfilename);
3068                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3069                 return false;
3070         }
3071         if(!copy_remaining_bytes_from_file_(iterator->file, *tempfile, &iterator->status)) {
3072                 cleanup_tempfile_(tempfile, tempfilename);
3073                 return false;
3074         }
3075
3076         if(fixup_is_last_code != 0) {
3077                 /*
3078                  * if code == 1, it means a block was appended to the end so
3079                  *   we have to clear the is_last flag of the previous block
3080                  * if code == -1, it means the last block was deleted so
3081                  *   we have to set the is_last flag of the previous block
3082                  */
3083                 /* MAGIC NUMBERs here; we know the is_last flag is the high bit of the byte at this location */
3084                 FLAC__byte x;
3085                 if(0 != fseeko(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
3086                         cleanup_tempfile_(tempfile, tempfilename);
3087                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3088                         return false;
3089                 }
3090                 if(fread(&x, 1, 1, *tempfile) != 1) {
3091                         cleanup_tempfile_(tempfile, tempfilename);
3092                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3093                         return false;
3094                 }
3095                 if(fixup_is_last_code > 0) {
3096                         FLAC__ASSERT(x & 0x80);
3097                         x &= 0x7f;
3098                 }
3099                 else {
3100                         FLAC__ASSERT(!(x & 0x80));
3101                         x |= 0x80;
3102                 }
3103                 if(0 != fseeko(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
3104                         cleanup_tempfile_(tempfile, tempfilename);
3105                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3106                         return false;
3107                 }
3108                 if(local__fwrite(&x, 1, 1, *tempfile) != 1) {
3109                         cleanup_tempfile_(tempfile, tempfilename);
3110                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3111                         return false;
3112                 }
3113         }
3114
3115         (void)fclose(iterator->file);
3116
3117         if(!transport_tempfile_(iterator->filename, tempfile, tempfilename, &iterator->status))
3118                 return false;
3119
3120         if(iterator->has_stats)
3121                 set_file_stats_(iterator->filename, &iterator->stats);
3122
3123         if(!simple_iterator_prime_input_(iterator, !iterator->is_writable))
3124                 return false;
3125         if(backup) {
3126                 while(iterator->offset[iterator->depth] + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length < save_offset)
3127                         if(!FLAC__metadata_simple_iterator_next(iterator))
3128                                 return false;
3129                 return true;
3130         }
3131         else {
3132                 /* move the iterator to it's original block faster by faking a push, then doing a pop_ */
3133                 FLAC__ASSERT(iterator->depth == 0);
3134                 iterator->offset[0] = save_offset;
3135                 iterator->depth++;
3136                 return simple_iterator_pop_(iterator);
3137         }
3138 }
3139
3140 FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status)
3141 {
3142         FLAC__byte buffer[8192];
3143         size_t n;
3144
3145         FLAC__ASSERT(bytes >= 0);
3146         while(bytes > 0) {
3147                 n = min(sizeof(buffer), (size_t)bytes);
3148                 if(fread(buffer, 1, n, file) != n) {
3149                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3150                         return false;
3151                 }
3152                 if(local__fwrite(buffer, 1, n, tempfile) != n) {
3153                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3154                         return false;
3155                 }
3156                 bytes -= n;
3157         }
3158
3159         return true;
3160 }
3161
3162 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)
3163 {
3164         FLAC__byte buffer[8192];
3165         size_t n;
3166
3167         FLAC__ASSERT(bytes >= 0);
3168         while(bytes > 0) {
3169                 n = min(sizeof(buffer), (size_t)bytes);
3170                 if(read_cb(buffer, 1, n, handle) != n) {
3171                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3172                         return false;
3173                 }
3174                 if(temp_write_cb(buffer, 1, n, temp_handle) != n) {
3175                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3176                         return false;
3177                 }
3178                 bytes -= n;
3179         }
3180
3181         return true;
3182 }
3183
3184 FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status)
3185 {
3186         FLAC__byte buffer[8192];
3187         size_t n;
3188
3189         while(!feof(file)) {
3190                 n = fread(buffer, 1, sizeof(buffer), file);
3191                 if(n == 0 && !feof(file)) {
3192                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3193                         return false;
3194                 }
3195                 if(n > 0 && local__fwrite(buffer, 1, n, tempfile) != n) {
3196                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3197                         return false;
3198                 }
3199         }
3200
3201         return true;
3202 }
3203
3204 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)
3205 {
3206         FLAC__byte buffer[8192];
3207         size_t n;
3208
3209         while(!eof_cb(handle)) {
3210                 n = read_cb(buffer, 1, sizeof(buffer), handle);
3211                 if(n == 0 && !eof_cb(handle)) {
3212                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3213                         return false;
3214                 }
3215                 if(n > 0 && temp_write_cb(buffer, 1, n, temp_handle) != n) {
3216                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3217                         return false;
3218                 }
3219         }
3220
3221         return true;
3222 }
3223
3224 FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
3225 {
3226         static const char *tempfile_suffix = ".metadata_edit";
3227         if(0 == tempfile_path_prefix) {
3228                 if(0 == (*tempfilename = (char*)safe_malloc_add_3op_(strlen(filename), /*+*/strlen(tempfile_suffix), /*+*/1))) {
3229                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
3230                         return false;
3231                 }
3232                 strcpy(*tempfilename, filename);
3233                 strcat(*tempfilename, tempfile_suffix);
3234         }
3235         else {
3236                 const char *p = strrchr(filename, '/');
3237                 if(0 == p)
3238                         p = filename;
3239                 else
3240                         p++;
3241
3242                 if(0 == (*tempfilename = (char*)safe_malloc_add_4op_(strlen(tempfile_path_prefix), /*+*/strlen(p), /*+*/strlen(tempfile_suffix), /*+*/2))) {
3243                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
3244                         return false;
3245                 }
3246                 strcpy(*tempfilename, tempfile_path_prefix);
3247                 strcat(*tempfilename, "/");
3248                 strcat(*tempfilename, p);
3249                 strcat(*tempfilename, tempfile_suffix);
3250         }
3251
3252         if(0 == (*tempfile = fopen(*tempfilename, "w+be"))) {
3253                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
3254                 return false;
3255         }
3256
3257         return true;
3258 }
3259
3260 FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
3261 {
3262         FLAC__ASSERT(0 != filename);
3263         FLAC__ASSERT(0 != tempfile);
3264         FLAC__ASSERT(0 != *tempfile);
3265         FLAC__ASSERT(0 != tempfilename);
3266         FLAC__ASSERT(0 != *tempfilename);
3267         FLAC__ASSERT(0 != status);
3268
3269         (void)fclose(*tempfile);
3270         *tempfile = 0;
3271
3272 #if defined _MSC_VER || defined __BORLANDC__ || defined __MINGW32__ || defined __EMX__
3273         /* on some flavors of windows, rename() will fail if the destination already exists */
3274         if(unlink(filename) < 0) {
3275                 cleanup_tempfile_(tempfile, tempfilename);
3276                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR;
3277                 return false;
3278         }
3279 #endif
3280
3281         /*@@@ to fully support the tempfile_path_prefix we need to update this piece to actually copy across filesystems instead of just rename(): */
3282         if(0 != rename(*tempfilename, filename)) {
3283                 cleanup_tempfile_(tempfile, tempfilename);
3284                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR;
3285                 return false;
3286         }
3287
3288         cleanup_tempfile_(tempfile, tempfilename);
3289
3290         return true;
3291 }
3292
3293 void cleanup_tempfile_(FILE **tempfile, char **tempfilename)
3294 {
3295         if(0 != *tempfile) {
3296                 (void)fclose(*tempfile);
3297                 *tempfile = 0;
3298         }
3299
3300         if(0 != *tempfilename) {
3301                 (void)unlink(*tempfilename);
3302                 free(*tempfilename);
3303                 *tempfilename = 0;
3304         }
3305 }
3306
3307 FLAC__bool get_file_stats_(const char *filename, struct stat *stats)
3308 {
3309         FLAC__ASSERT(0 != filename);
3310         FLAC__ASSERT(0 != stats);
3311         return (0 == stat(filename, stats));
3312 }
3313
3314 void set_file_stats_(const char *filename, struct stat *stats)
3315 {
3316         struct utimbuf srctime;
3317
3318         FLAC__ASSERT(0 != filename);
3319         FLAC__ASSERT(0 != stats);
3320
3321         srctime.actime = stats->st_atime;
3322         srctime.modtime = stats->st_mtime;
3323         (void)chmod(filename, stats->st_mode);
3324         (void)utime(filename, &srctime);
3325 #if !defined _MSC_VER && !defined __BORLANDC__ && !defined __MINGW32__ && !defined __EMX__
3326         (void)chown(filename, stats->st_uid, -1);
3327         (void)chown(filename, -1, stats->st_gid);
3328 #endif
3329 }
3330
3331 int fseek_wrapper_(FLAC__IOHandle handle, FLAC__int64 offset, int whence)
3332 {
3333         return fseeko((FILE*)handle, (off_t)offset, whence);
3334 }
3335
3336 FLAC__int64 ftell_wrapper_(FLAC__IOHandle handle)
3337 {
3338         return ftello((FILE*)handle);
3339 }
3340
3341 FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status)
3342 {
3343         switch(status) {
3344                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK:
3345                         return FLAC__METADATA_CHAIN_STATUS_OK;
3346                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT:
3347                         return FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT;
3348                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE:
3349                         return FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
3350                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE:
3351                         return FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE;
3352                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE:
3353                         return FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE;
3354                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA:
3355                         return FLAC__METADATA_CHAIN_STATUS_BAD_METADATA;
3356                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR:
3357                         return FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
3358                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR:
3359                         return FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
3360                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR:
3361                         return FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
3362                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR:
3363                         return FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR;
3364                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR:
3365                         return FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR;
3366                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR:
3367                         return FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
3368                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR:
3369                 default:
3370                         return FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
3371         }
3372 }