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+b"))) {
 442                 iterator->is_writable = false;
 443                 if(read_only || errno == EACCES) {
 444                         if(0 == (iterator->file = fopen(iterator->filename, "rb"))) {
 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                                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1221                                 return false;
1222                         }
1223
1224                         node->data = FLAC__metadata_object_new(type);
1225                         if(0 == node->data) {
1226                                 node_delete_(node);
1227                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1228                                 return false;
1229                         }
1230
1231                         node->data->is_last = is_last;
1232                         node->data->length = length;
1233
1234                         chain->status = get_equivalent_status_(read_metadata_block_data_cb_(handle, read_cb, seek_cb, node->data));
1235                         if(chain->status != FLAC__METADATA_CHAIN_STATUS_OK) {
1236                                 node_delete_(node);
1237                                 return false;
1238                         }
1239                         chain_append_node_(chain, node);
1240                 } while(!is_last);
1241         }
1242
1243         {
1244                 FLAC__int64 pos = tell_cb(handle);
1245                 if(pos < 0) {
1246                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1247                         return false;
1248                 }
1249                 chain->last_offset = (off_t)pos;
1250         }
1251
1252         chain->initial_length = chain_calculate_length_(chain);
1253
1254         return true;
1255 }
1256
1257 static FLAC__StreamDecoderReadStatus chain_read_ogg_read_cb_(const FLAC__StreamDecoder *decoder, FLAC__byte buffer[], size_t *bytes, void *client_data)
1258 {
1259         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1260         (void)decoder;
1261         if(*bytes > 0 && chain->status == FLAC__METADATA_CHAIN_STATUS_OK) {
1262                 *bytes = chain->read_cb(buffer, sizeof(FLAC__byte), *bytes, chain->handle);
1263                 if(*bytes == 0)
1264                         return FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM;
1265                 else
1266                         return FLAC__STREAM_DECODER_READ_STATUS_CONTINUE;
1267         }
1268         else
1269                 return FLAC__STREAM_DECODER_READ_STATUS_ABORT;
1270 }
1271
1272 static FLAC__StreamDecoderWriteStatus chain_read_ogg_write_cb_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
1273 {
1274         (void)decoder, (void)frame, (void)buffer, (void)client_data;
1275         return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
1276 }
1277
1278 static void chain_read_ogg_metadata_cb_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
1279 {
1280         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1281         FLAC__Metadata_Node *node;
1282
1283         (void)decoder;
1284
1285         node = node_new_();
1286         if(0 == node) {
1287                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1288                 return;
1289         }
1290
1291         node->data = FLAC__metadata_object_clone(metadata);
1292         if(0 == node->data) {
1293                 node_delete_(node);
1294                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1295                 return;
1296         }
1297
1298         chain_append_node_(chain, node);
1299 }
1300
1301 static void chain_read_ogg_error_cb_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
1302 {
1303         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1304         (void)decoder, (void)status;
1305         chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1306 }
1307
1308 static FLAC__bool chain_read_ogg_cb_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb)
1309 {
1310         FLAC__StreamDecoder *decoder;
1311
1312         FLAC__ASSERT(0 != chain);
1313
1314         /* we assume we're already at the beginning of the file */
1315
1316         chain->handle = handle;
1317         chain->read_cb = read_cb;
1318         if(0 == (decoder = FLAC__stream_decoder_new())) {
1319                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1320                 return false;
1321         }
1322         FLAC__stream_decoder_set_metadata_respond_all(decoder);
1323         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) {
1324                 FLAC__stream_decoder_delete(decoder);
1325                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1326                 return false;
1327         }
1328
1329         chain->first_offset = 0; /*@@@ wrong; will need to be set correctly to implement metadata writing for Ogg FLAC */
1330
1331         if(!FLAC__stream_decoder_process_until_end_of_metadata(decoder))
1332                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1333         if(chain->status != FLAC__METADATA_CHAIN_STATUS_OK) {
1334                 FLAC__stream_decoder_delete(decoder);
1335                 return false;
1336         }
1337
1338         FLAC__stream_decoder_delete(decoder);
1339
1340         chain->last_offset = 0; /*@@@ wrong; will need to be set correctly to implement metadata writing for Ogg FLAC */
1341
1342         chain->initial_length = chain_calculate_length_(chain);
1343
1344         return true;
1345 }
1346
1347 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)
1348 {
1349         FLAC__Metadata_Node *node;
1350
1351         FLAC__ASSERT(0 != chain);
1352         FLAC__ASSERT(0 != chain->head);
1353
1354         if(0 != seek_cb(handle, chain->first_offset, SEEK_SET)) {
1355                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1356                 return false;
1357         }
1358
1359         for(node = chain->head; node; node = node->next) {
1360                 if(!write_metadata_block_header_cb_(handle, write_cb, node->data)) {
1361                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1362                         return false;
1363                 }
1364                 if(!write_metadata_block_data_cb_(handle, write_cb, node->data)) {
1365                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1366                         return false;
1367                 }
1368         }
1369
1370         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1371
1372         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
1373         return true;
1374 }
1375
1376 static FLAC__bool chain_rewrite_metadata_in_place_(FLAC__Metadata_Chain *chain)
1377 {
1378         FILE *file;
1379         FLAC__bool ret;
1380
1381         FLAC__ASSERT(0 != chain->filename);
1382
1383         if(0 == (file = fopen(chain->filename, "r+b"))) {
1384                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1385                 return false;
1386         }
1387
1388         /* chain_rewrite_metadata_in_place_cb_() sets chain->status for us */
1389         ret = chain_rewrite_metadata_in_place_cb_(chain, (FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, fseek_wrapper_);
1390
1391         fclose(file);
1392
1393         return ret;
1394 }
1395
1396 static FLAC__bool chain_rewrite_file_(FLAC__Metadata_Chain *chain, const char *tempfile_path_prefix)
1397 {
1398         FILE *f, *tempfile;
1399         char *tempfilename;
1400         FLAC__Metadata_SimpleIteratorStatus status;
1401         const FLAC__Metadata_Node *node;
1402
1403         FLAC__ASSERT(0 != chain);
1404         FLAC__ASSERT(0 != chain->filename);
1405         FLAC__ASSERT(0 != chain->head);
1406
1407         /* copy the file prefix (data up to first metadata block */
1408         if(0 == (f = fopen(chain->filename, "rb"))) {
1409                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1410                 return false;
1411         }
1412         if(!open_tempfile_(chain->filename, tempfile_path_prefix, &tempfile, &tempfilename, &status)) {
1413                 chain->status = get_equivalent_status_(status);
1414                 cleanup_tempfile_(&tempfile, &tempfilename);
1415                 return false;
1416         }
1417         if(!copy_n_bytes_from_file_(f, tempfile, chain->first_offset, &status)) {
1418                 chain->status = get_equivalent_status_(status);
1419                 cleanup_tempfile_(&tempfile, &tempfilename);
1420                 return false;
1421         }
1422
1423         /* write the metadata */
1424         for(node = chain->head; node; node = node->next) {
1425                 if(!write_metadata_block_header_(tempfile, &status, node->data)) {
1426                         chain->status = get_equivalent_status_(status);
1427                         return false;
1428                 }
1429                 if(!write_metadata_block_data_(tempfile, &status, node->data)) {
1430                         chain->status = get_equivalent_status_(status);
1431                         return false;
1432                 }
1433         }
1434         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1435
1436         /* copy the file postfix (everything after the metadata) */
1437         if(0 != fseeko(f, chain->last_offset, SEEK_SET)) {
1438                 cleanup_tempfile_(&tempfile, &tempfilename);
1439                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1440                 return false;
1441         }
1442         if(!copy_remaining_bytes_from_file_(f, tempfile, &status)) {
1443                 cleanup_tempfile_(&tempfile, &tempfilename);
1444                 chain->status = get_equivalent_status_(status);
1445                 return false;
1446         }
1447
1448         /* move the tempfile on top of the original */
1449         (void)fclose(f);
1450         if(!transport_tempfile_(chain->filename, &tempfile, &tempfilename, &status))
1451                 return false;
1452
1453         return true;
1454 }
1455
1456 /* assumes 'handle' is already at beginning of file */
1457 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)
1458 {
1459         FLAC__Metadata_SimpleIteratorStatus status;
1460         const FLAC__Metadata_Node *node;
1461
1462         FLAC__ASSERT(0 != chain);
1463         FLAC__ASSERT(0 == chain->filename);
1464         FLAC__ASSERT(0 != chain->head);
1465
1466         /* copy the file prefix (data up to first metadata block */
1467         if(!copy_n_bytes_from_file_cb_(handle, read_cb, temp_handle, temp_write_cb, chain->first_offset, &status)) {
1468                 chain->status = get_equivalent_status_(status);
1469                 return false;
1470         }
1471
1472         /* write the metadata */
1473         for(node = chain->head; node; node = node->next) {
1474                 if(!write_metadata_block_header_cb_(temp_handle, temp_write_cb, node->data)) {
1475                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1476                         return false;
1477                 }
1478                 if(!write_metadata_block_data_cb_(temp_handle, temp_write_cb, node->data)) {
1479                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1480                         return false;
1481                 }
1482         }
1483         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1484
1485         /* copy the file postfix (everything after the metadata) */
1486         if(0 != seek_cb(handle, chain->last_offset, SEEK_SET)) {
1487                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1488                 return false;
1489         }
1490         if(!copy_remaining_bytes_from_file_cb_(handle, read_cb, eof_cb, temp_handle, temp_write_cb, &status)) {
1491                 chain->status = get_equivalent_status_(status);
1492                 return false;
1493         }
1494
1495         return true;
1496 }
1497
1498 FLAC_API FLAC__Metadata_Chain *FLAC__metadata_chain_new(void)
1499 {
1500         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)calloc(1, sizeof(FLAC__Metadata_Chain));
1501
1502         if(0 != chain)
1503                 chain_init_(chain);
1504
1505         return chain;
1506 }
1507
1508 FLAC_API void FLAC__metadata_chain_delete(FLAC__Metadata_Chain *chain)
1509 {
1510         FLAC__ASSERT(0 != chain);
1511
1512         chain_clear_(chain);
1513
1514         free(chain);
1515 }
1516
1517 FLAC_API FLAC__Metadata_ChainStatus FLAC__metadata_chain_status(FLAC__Metadata_Chain *chain)
1518 {
1519         FLAC__Metadata_ChainStatus status;
1520
1521         FLAC__ASSERT(0 != chain);
1522
1523         status = chain->status;
1524         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
1525         return status;
1526 }
1527
1528 static FLAC__bool chain_read_(FLAC__Metadata_Chain *chain, const char *filename, FLAC__bool is_ogg)
1529 {
1530         FILE *file;
1531         FLAC__bool ret;
1532
1533         FLAC__ASSERT(0 != chain);
1534         FLAC__ASSERT(0 != filename);
1535
1536         chain_clear_(chain);
1537
1538         if(0 == (chain->filename = strdup(filename))) {
1539                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1540                 return false;
1541         }
1542
1543         chain->is_ogg = is_ogg;
1544
1545         if(0 == (file = fopen(filename, "rb"))) {
1546                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1547                 return false;
1548         }
1549
1550         /* the function also sets chain->status for us */
1551         ret = is_ogg?
1552                 chain_read_ogg_cb_(chain, file, (FLAC__IOCallback_Read)fread) :
1553                 chain_read_cb_(chain, file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, ftell_wrapper_)
1554         ;
1555
1556         fclose(file);
1557
1558         return ret;
1559 }
1560
1561 FLAC_API FLAC__bool FLAC__metadata_chain_read(FLAC__Metadata_Chain *chain, const char *filename)
1562 {
1563         return chain_read_(chain, filename, /*is_ogg=*/false);
1564 }
1565
1566 /*@@@@add to tests*/
1567 FLAC_API FLAC__bool FLAC__metadata_chain_read_ogg(FLAC__Metadata_Chain *chain, const char *filename)
1568 {
1569         return chain_read_(chain, filename, /*is_ogg=*/true);
1570 }
1571
1572 static FLAC__bool chain_read_with_callbacks_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks, FLAC__bool is_ogg)
1573 {
1574         FLAC__bool ret;
1575
1576         FLAC__ASSERT(0 != chain);
1577
1578         chain_clear_(chain);
1579
1580         if (0 == callbacks.read || 0 == callbacks.seek || 0 == callbacks.tell) {
1581                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1582                 return false;
1583         }
1584
1585         chain->is_ogg = is_ogg;
1586
1587         /* rewind */
1588         if(0 != callbacks.seek(handle, 0, SEEK_SET)) {
1589                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1590                 return false;
1591         }
1592
1593         /* the function also sets chain->status for us */
1594         ret = is_ogg?
1595                 chain_read_ogg_cb_(chain, handle, callbacks.read) :
1596                 chain_read_cb_(chain, handle, callbacks.read, callbacks.seek, callbacks.tell)
1597         ;
1598
1599         return ret;
1600 }
1601
1602 FLAC_API FLAC__bool FLAC__metadata_chain_read_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1603 {
1604         return chain_read_with_callbacks_(chain, handle, callbacks, /*is_ogg=*/false);
1605 }
1606
1607 /*@@@@add to tests*/
1608 FLAC_API FLAC__bool FLAC__metadata_chain_read_ogg_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1609 {
1610         return chain_read_with_callbacks_(chain, handle, callbacks, /*is_ogg=*/true);
1611 }
1612
1613 FLAC_API FLAC__bool FLAC__metadata_chain_check_if_tempfile_needed(FLAC__Metadata_Chain *chain, FLAC__bool use_padding)
1614 {
1615         /* This does all the same checks that are in chain_prepare_for_write_()
1616          * but doesn't actually alter the chain.  Make sure to update the logic
1617          * here if chain_prepare_for_write_() changes.
1618          */
1619         const off_t current_length = chain_calculate_length_(chain);
1620
1621         FLAC__ASSERT(0 != chain);
1622
1623         if(use_padding) {
1624                 /* if the metadata shrank and the last block is padding, we just extend the last padding block */
1625                 if(current_length < chain->initial_length && chain->tail->data->type == FLAC__METADATA_TYPE_PADDING)
1626                         return false;
1627                 /* if the metadata shrank more than 4 bytes then there's room to add another padding block */
1628                 else if(current_length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH <= chain->initial_length)
1629                         return false;
1630                 /* 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 */
1631                 else if(current_length > chain->initial_length) {
1632                         const off_t delta = current_length - chain->initial_length;
1633                         if(chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1634                                 /* if the delta is exactly the size of the last padding block, remove the padding block */
1635                                 if((off_t)chain->tail->data->length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH == delta)
1636                                         return false;
1637                                 /* if there is at least 'delta' bytes of padding, trim the padding down */
1638                                 else if((off_t)chain->tail->data->length >= delta)
1639                                         return false;
1640                         }
1641                 }
1642         }
1643
1644         return (current_length != chain->initial_length);
1645 }
1646
1647 FLAC_API FLAC__bool FLAC__metadata_chain_write(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__bool preserve_file_stats)
1648 {
1649         struct stat stats;
1650         const char *tempfile_path_prefix = 0;
1651         off_t current_length;
1652
1653         FLAC__ASSERT(0 != chain);
1654
1655         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1656                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1657                 return false;
1658         }
1659
1660         if (0 == chain->filename) {
1661                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1662                 return false;
1663         }
1664
1665         current_length = chain_prepare_for_write_(chain, use_padding);
1666
1667         /* a return value of 0 means there was an error; chain->status is already set */
1668         if (0 == current_length)
1669                 return false;
1670
1671         if(preserve_file_stats)
1672                 get_file_stats_(chain->filename, &stats);
1673
1674         if(current_length == chain->initial_length) {
1675                 if(!chain_rewrite_metadata_in_place_(chain))
1676                         return false;
1677         }
1678         else {
1679                 if(!chain_rewrite_file_(chain, tempfile_path_prefix))
1680                         return false;
1681
1682                 /* recompute lengths and offsets */
1683                 {
1684                         const FLAC__Metadata_Node *node;
1685                         chain->initial_length = current_length;
1686                         chain->last_offset = chain->first_offset;
1687                         for(node = chain->head; node; node = node->next)
1688                                 chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1689                 }
1690         }
1691
1692         if(preserve_file_stats)
1693                 set_file_stats_(chain->filename, &stats);
1694
1695         return true;
1696 }
1697
1698 FLAC_API FLAC__bool FLAC__metadata_chain_write_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1699 {
1700         off_t current_length;
1701
1702         FLAC__ASSERT(0 != chain);
1703
1704         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1705                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1706                 return false;
1707         }
1708
1709         if (0 != chain->filename) {
1710                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1711                 return false;
1712         }
1713
1714         if (0 == callbacks.write || 0 == callbacks.seek) {
1715                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1716                 return false;
1717         }
1718
1719         if (FLAC__metadata_chain_check_if_tempfile_needed(chain, use_padding)) {
1720                 chain->status = FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL;
1721                 return false;
1722         }
1723
1724         current_length = chain_prepare_for_write_(chain, use_padding);
1725
1726         /* a return value of 0 means there was an error; chain->status is already set */
1727         if (0 == current_length)
1728                 return false;
1729
1730         FLAC__ASSERT(current_length == chain->initial_length);
1731
1732         return chain_rewrite_metadata_in_place_cb_(chain, handle, callbacks.write, callbacks.seek);
1733 }
1734
1735 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)
1736 {
1737         off_t current_length;
1738
1739         FLAC__ASSERT(0 != chain);
1740
1741         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1742                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1743                 return false;
1744         }
1745
1746         if (0 != chain->filename) {
1747                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1748                 return false;
1749         }
1750
1751         if (0 == callbacks.read || 0 == callbacks.seek || 0 == callbacks.eof) {
1752                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1753                 return false;
1754         }
1755         if (0 == temp_callbacks.write) {
1756                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1757                 return false;
1758         }
1759
1760         if (!FLAC__metadata_chain_check_if_tempfile_needed(chain, use_padding)) {
1761                 chain->status = FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL;
1762                 return false;
1763         }
1764
1765         current_length = chain_prepare_for_write_(chain, use_padding);
1766
1767         /* a return value of 0 means there was an error; chain->status is already set */
1768         if (0 == current_length)
1769                 return false;
1770
1771         FLAC__ASSERT(current_length != chain->initial_length);
1772
1773         /* rewind */
1774         if(0 != callbacks.seek(handle, 0, SEEK_SET)) {
1775                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1776                 return false;
1777         }
1778
1779         if(!chain_rewrite_file_cb_(chain, handle, callbacks.read, callbacks.seek, callbacks.eof, temp_handle, temp_callbacks.write))
1780                 return false;
1781
1782         /* recompute lengths and offsets */
1783         {
1784                 const FLAC__Metadata_Node *node;
1785                 chain->initial_length = current_length;
1786                 chain->last_offset = chain->first_offset;
1787                 for(node = chain->head; node; node = node->next)
1788                         chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1789         }
1790
1791         return true;
1792 }
1793
1794 FLAC_API void FLAC__metadata_chain_merge_padding(FLAC__Metadata_Chain *chain)
1795 {
1796         FLAC__Metadata_Node *node;
1797
1798         FLAC__ASSERT(0 != chain);
1799
1800         for(node = chain->head; node; ) {
1801                 if(!chain_merge_adjacent_padding_(chain, node))
1802                         node = node->next;
1803         }
1804 }
1805
1806 FLAC_API void FLAC__metadata_chain_sort_padding(FLAC__Metadata_Chain *chain)
1807 {
1808         FLAC__Metadata_Node *node, *save;
1809         unsigned i;
1810
1811         FLAC__ASSERT(0 != chain);
1812
1813         /*
1814          * Don't try and be too smart... this simple algo is good enough for
1815          * the small number of nodes that we deal with.
1816          */
1817         for(i = 0, node = chain->head; i < chain->nodes; i++) {
1818                 if(node->data->type == FLAC__METADATA_TYPE_PADDING) {
1819                         save = node->next;
1820                         chain_remove_node_(chain, node);
1821                         chain_append_node_(chain, node);
1822                         node = save;
1823                 }
1824                 else {
1825                         node = node->next;
1826                 }
1827         }
1828
1829         FLAC__metadata_chain_merge_padding(chain);
1830 }
1831
1832
1833 FLAC_API FLAC__Metadata_Iterator *FLAC__metadata_iterator_new(void)
1834 {
1835         FLAC__Metadata_Iterator *iterator = (FLAC__Metadata_Iterator*)calloc(1, sizeof(FLAC__Metadata_Iterator));
1836
1837         /* calloc() implies:
1838                 iterator->current = 0;
1839                 iterator->chain = 0;
1840         */
1841
1842         return iterator;
1843 }
1844
1845 FLAC_API void FLAC__metadata_iterator_delete(FLAC__Metadata_Iterator *iterator)
1846 {
1847         FLAC__ASSERT(0 != iterator);
1848
1849         free(iterator);
1850 }
1851
1852 FLAC_API void FLAC__metadata_iterator_init(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Chain *chain)
1853 {
1854         FLAC__ASSERT(0 != iterator);
1855         FLAC__ASSERT(0 != chain);
1856         FLAC__ASSERT(0 != chain->head);
1857
1858         iterator->chain = chain;
1859         iterator->current = chain->head;
1860 }
1861
1862 FLAC_API FLAC__bool FLAC__metadata_iterator_next(FLAC__Metadata_Iterator *iterator)
1863 {
1864         FLAC__ASSERT(0 != iterator);
1865
1866         if(0 == iterator->current || 0 == iterator->current->next)
1867                 return false;
1868
1869         iterator->current = iterator->current->next;
1870         return true;
1871 }
1872
1873 FLAC_API FLAC__bool FLAC__metadata_iterator_prev(FLAC__Metadata_Iterator *iterator)
1874 {
1875         FLAC__ASSERT(0 != iterator);
1876
1877         if(0 == iterator->current || 0 == iterator->current->prev)
1878                 return false;
1879
1880         iterator->current = iterator->current->prev;
1881         return true;
1882 }
1883
1884 FLAC_API FLAC__MetadataType FLAC__metadata_iterator_get_block_type(const FLAC__Metadata_Iterator *iterator)
1885 {
1886         FLAC__ASSERT(0 != iterator);
1887         FLAC__ASSERT(0 != iterator->current);
1888         FLAC__ASSERT(0 != iterator->current->data);
1889
1890         return iterator->current->data->type;
1891 }
1892
1893 FLAC_API FLAC__StreamMetadata *FLAC__metadata_iterator_get_block(FLAC__Metadata_Iterator *iterator)
1894 {
1895         FLAC__ASSERT(0 != iterator);
1896         FLAC__ASSERT(0 != iterator->current);
1897
1898         return iterator->current->data;
1899 }
1900
1901 FLAC_API FLAC__bool FLAC__metadata_iterator_set_block(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1902 {
1903         FLAC__ASSERT(0 != iterator);
1904         FLAC__ASSERT(0 != block);
1905         return FLAC__metadata_iterator_delete_block(iterator, false) && FLAC__metadata_iterator_insert_block_after(iterator, block);
1906 }
1907
1908 FLAC_API FLAC__bool FLAC__metadata_iterator_delete_block(FLAC__Metadata_Iterator *iterator, FLAC__bool replace_with_padding)
1909 {
1910         FLAC__Metadata_Node *save;
1911
1912         FLAC__ASSERT(0 != iterator);
1913         FLAC__ASSERT(0 != iterator->current);
1914
1915         if(0 == iterator->current->prev) {
1916                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1917                 return false;
1918         }
1919
1920         save = iterator->current->prev;
1921
1922         if(replace_with_padding) {
1923                 FLAC__metadata_object_delete_data(iterator->current->data);
1924                 iterator->current->data->type = FLAC__METADATA_TYPE_PADDING;
1925         }
1926         else {
1927                 chain_delete_node_(iterator->chain, iterator->current);
1928         }
1929
1930         iterator->current = save;
1931         return true;
1932 }
1933
1934 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_before(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1935 {
1936         FLAC__Metadata_Node *node;
1937
1938         FLAC__ASSERT(0 != iterator);
1939         FLAC__ASSERT(0 != iterator->current);
1940         FLAC__ASSERT(0 != block);
1941
1942         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1943                 return false;
1944
1945         if(0 == iterator->current->prev) {
1946                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1947                 return false;
1948         }
1949
1950         if(0 == (node = node_new_()))
1951                 return false;
1952
1953         node->data = block;
1954         iterator_insert_node_(iterator, node);
1955         iterator->current = node;
1956         return true;
1957 }
1958
1959 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_after(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1960 {
1961         FLAC__Metadata_Node *node;
1962
1963         FLAC__ASSERT(0 != iterator);
1964         FLAC__ASSERT(0 != iterator->current);
1965         FLAC__ASSERT(0 != block);
1966
1967         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1968                 return false;
1969
1970         if(0 == (node = node_new_()))
1971                 return false;
1972
1973         node->data = block;
1974         iterator_insert_node_after_(iterator, node);
1975         iterator->current = node;
1976         return true;
1977 }
1978
1979
1980 /****************************************************************************
1981  *
1982  * Local function definitions
1983  *
1984  ***************************************************************************/
1985
1986 void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
1987 {
1988         unsigned i;
1989
1990         b += bytes;
1991
1992         for(i = 0; i < bytes; i++) {
1993                 *(--b) = (FLAC__byte)(val & 0xff);
1994                 val >>= 8;
1995         }
1996 }
1997
1998 void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
1999 {
2000         unsigned i;
2001
2002         for(i = 0; i < bytes; i++) {
2003                 *(b++) = (FLAC__byte)(val & 0xff);
2004                 val >>= 8;
2005         }
2006 }
2007
2008 void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes)
2009 {
2010         unsigned i;
2011
2012         b += bytes;
2013
2014         for(i = 0; i < bytes; i++) {
2015                 *(--b) = (FLAC__byte)(val & 0xff);
2016                 val >>= 8;
2017         }
2018 }
2019
2020 FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes)
2021 {
2022         FLAC__uint32 ret = 0;
2023         unsigned i;
2024
2025         for(i = 0; i < bytes; i++)
2026                 ret = (ret << 8) | (FLAC__uint32)(*b++);
2027
2028         return ret;
2029 }
2030
2031 FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes)
2032 {
2033         FLAC__uint32 ret = 0;
2034         unsigned i;
2035
2036         b += bytes;
2037
2038         for(i = 0; i < bytes; i++)
2039                 ret = (ret << 8) | (FLAC__uint32)(*--b);
2040
2041         return ret;
2042 }
2043
2044 FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes)
2045 {
2046         FLAC__uint64 ret = 0;
2047         unsigned i;
2048
2049         for(i = 0; i < bytes; i++)
2050                 ret = (ret << 8) | (FLAC__uint64)(*b++);
2051
2052         return ret;
2053 }
2054
2055 FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator)
2056 {
2057         FLAC__ASSERT(0 != iterator);
2058         FLAC__ASSERT(0 != iterator->file);
2059
2060         if(!read_metadata_block_header_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, &iterator->is_last, &iterator->type, &iterator->length)) {
2061                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2062                 return false;
2063         }
2064
2065         return true;
2066 }
2067
2068 FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block)
2069 {
2070         FLAC__ASSERT(0 != iterator);
2071         FLAC__ASSERT(0 != iterator->file);
2072
2073         iterator->status = read_metadata_block_data_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, block);
2074
2075         return (iterator->status == FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK);
2076 }
2077
2078 FLAC__bool read_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__bool *is_last, FLAC__MetadataType *type, unsigned *length)
2079 {
2080         FLAC__byte raw_header[FLAC__STREAM_METADATA_HEADER_LENGTH];
2081
2082         if(read_cb(raw_header, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
2083                 return false;
2084
2085         *is_last = raw_header[0] & 0x80? true : false;
2086         *type = (FLAC__MetadataType)(raw_header[0] & 0x7f);
2087         *length = unpack_uint32_(raw_header + 1, 3);
2088
2089         /* Note that we don't check:
2090          *    if(iterator->type >= FLAC__METADATA_TYPE_UNDEFINED)
2091          * we just will read in an opaque block
2092          */
2093
2094         return true;
2095 }
2096
2097 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata *block)
2098 {
2099         switch(block->type) {
2100                 case FLAC__METADATA_TYPE_STREAMINFO:
2101                         return read_metadata_block_data_streaminfo_cb_(handle, read_cb, &block->data.stream_info);
2102                 case FLAC__METADATA_TYPE_PADDING:
2103                         return read_metadata_block_data_padding_cb_(handle, seek_cb, &block->data.padding, block->length);
2104                 case FLAC__METADATA_TYPE_APPLICATION:
2105                         return read_metadata_block_data_application_cb_(handle, read_cb, &block->data.application, block->length);
2106                 case FLAC__METADATA_TYPE_SEEKTABLE:
2107                         return read_metadata_block_data_seektable_cb_(handle, read_cb, &block->data.seek_table, block->length);
2108                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
2109                         return read_metadata_block_data_vorbis_comment_cb_(handle, read_cb, &block->data.vorbis_comment);
2110                 case FLAC__METADATA_TYPE_CUESHEET:
2111                         return read_metadata_block_data_cuesheet_cb_(handle, read_cb, &block->data.cue_sheet);
2112                 case FLAC__METADATA_TYPE_PICTURE:
2113                         return read_metadata_block_data_picture_cb_(handle, read_cb, &block->data.picture);
2114                 default:
2115                         return read_metadata_block_data_unknown_cb_(handle, read_cb, &block->data.unknown, block->length);
2116         }
2117 }
2118
2119 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_StreamInfo *block)
2120 {
2121         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH], *b;
2122
2123         if(read_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
2124                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2125
2126         b = buffer;
2127
2128         /* we are using hardcoded numbers for simplicity but we should
2129          * probably eventually write a bit-level unpacker and use the
2130          * _STREAMINFO_ constants.
2131          */
2132         block->min_blocksize = unpack_uint32_(b, 2); b += 2;
2133         block->max_blocksize = unpack_uint32_(b, 2); b += 2;
2134         block->min_framesize = unpack_uint32_(b, 3); b += 3;
2135         block->max_framesize = unpack_uint32_(b, 3); b += 3;
2136         block->sample_rate = (unpack_uint32_(b, 2) << 4) | ((unsigned)(b[2] & 0xf0) >> 4);
2137         block->channels = (unsigned)((b[2] & 0x0e) >> 1) + 1;
2138         block->bits_per_sample = ((((unsigned)(b[2] & 0x01)) << 4) | (((unsigned)(b[3] & 0xf0)) >> 4)) + 1;
2139         block->total_samples = (((FLAC__uint64)(b[3] & 0x0f)) << 32) | unpack_uint64_(b+4, 4);
2140         memcpy(block->md5sum, b+8, 16);
2141
2142         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2143 }
2144
2145 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata_Padding *block, unsigned block_length)
2146 {
2147         (void)block; /* nothing to do; we don't care about reading the padding bytes */
2148
2149         if(0 != seek_cb(handle, block_length, SEEK_CUR))
2150                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2151
2152         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2153 }
2154
2155 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Application *block, unsigned block_length)
2156 {
2157         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
2158
2159         if(read_cb(block->id, 1, id_bytes, handle) != id_bytes)
2160                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2161
2162         if(block_length < id_bytes)
2163                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2164
2165         block_length -= id_bytes;
2166
2167         if(block_length == 0) {
2168                 block->data = 0;
2169         }
2170         else {
2171                 if(0 == (block->data = (FLAC__byte*)malloc(block_length)))
2172                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2173
2174                 if(read_cb(block->data, 1, block_length, handle) != block_length)
2175                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2176         }
2177
2178         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2179 }
2180
2181 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_SeekTable *block, unsigned block_length)
2182 {
2183         unsigned i;
2184         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
2185
2186         FLAC__ASSERT(block_length % FLAC__STREAM_METADATA_SEEKPOINT_LENGTH == 0);
2187
2188         block->num_points = block_length / FLAC__STREAM_METADATA_SEEKPOINT_LENGTH;
2189
2190         if(block->num_points == 0)
2191                 block->points = 0;
2192         else if(0 == (block->points = (FLAC__StreamMetadata_SeekPoint*)safe_malloc_mul_2op_(block->num_points, /*times*/sizeof(FLAC__StreamMetadata_SeekPoint))))
2193                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2194
2195         for(i = 0; i < block->num_points; i++) {
2196                 if(read_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
2197                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2198                 /* some MAGIC NUMBERs here */
2199                 block->points[i].sample_number = unpack_uint64_(buffer, 8);
2200                 block->points[i].stream_offset = unpack_uint64_(buffer+8, 8);
2201                 block->points[i].frame_samples = unpack_uint32_(buffer+16, 2);
2202         }
2203
2204         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2205 }
2206
2207 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_entry_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment_Entry *entry)
2208 {
2209         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
2210         FLAC__byte buffer[4]; /* magic number is asserted below */
2211
2212         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8 == sizeof(buffer));
2213
2214         if(read_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2215                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2216         entry->length = unpack_uint32_little_endian_(buffer, entry_length_len);
2217
2218         if(0 != entry->entry)
2219                 free(entry->entry);
2220
2221         if(entry->length == 0) {
2222                 entry->entry = 0;
2223         }
2224         else {
2225                 if(0 == (entry->entry = (FLAC__byte*)safe_malloc_add_2op_(entry->length, /*+*/1)))
2226                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2227
2228                 if(read_cb(entry->entry, 1, entry->length, handle) != entry->length)
2229                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2230
2231                 entry->entry[entry->length] = '\0';
2232         }
2233
2234         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2235 }
2236
2237 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment *block)
2238 {
2239         unsigned i;
2240         FLAC__Metadata_SimpleIteratorStatus status;
2241         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2242         FLAC__byte buffer[4]; /* magic number is asserted below */
2243
2244         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8 == sizeof(buffer));
2245
2246         if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, &(block->vendor_string))))
2247                 return status;
2248
2249         if(read_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2250                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2251         block->num_comments = unpack_uint32_little_endian_(buffer, num_comments_len);
2252
2253         if(block->num_comments == 0) {
2254                 block->comments = 0;
2255         }
2256         else if(0 == (block->comments = (FLAC__StreamMetadata_VorbisComment_Entry*)calloc(block->num_comments, sizeof(FLAC__StreamMetadata_VorbisComment_Entry))))
2257                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2258
2259         for(i = 0; i < block->num_comments; i++) {
2260                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, block->comments + i)))
2261                         return status;
2262         }
2263
2264         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2265 }
2266
2267 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet_Track *track)
2268 {
2269         unsigned i, len;
2270         FLAC__byte buffer[32]; /* asserted below that this is big enough */
2271
2272         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2273         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2274         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);
2275
2276         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2277         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2278         if(read_cb(buffer, 1, len, handle) != len)
2279                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2280         track->offset = unpack_uint64_(buffer, len);
2281
2282         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2283         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2284         if(read_cb(buffer, 1, len, handle) != len)
2285                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2286         track->number = (FLAC__byte)unpack_uint32_(buffer, len);
2287
2288         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2289         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2290         if(read_cb(track->isrc, 1, len, handle) != len)
2291                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2292
2293         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);
2294         len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2295         if(read_cb(buffer, 1, len, handle) != len)
2296                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2297         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN == 1);
2298         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN == 1);
2299         track->type = buffer[0] >> 7;
2300         track->pre_emphasis = (buffer[0] >> 6) & 1;
2301
2302         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2303         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2304         if(read_cb(buffer, 1, len, handle) != len)
2305                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2306         track->num_indices = (FLAC__byte)unpack_uint32_(buffer, len);
2307
2308         if(track->num_indices == 0) {
2309                 track->indices = 0;
2310         }
2311         else if(0 == (track->indices = (FLAC__StreamMetadata_CueSheet_Index*)calloc(track->num_indices, sizeof(FLAC__StreamMetadata_CueSheet_Index))))
2312                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2313
2314         for(i = 0; i < track->num_indices; i++) {
2315                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2316                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2317                 if(read_cb(buffer, 1, len, handle) != len)
2318                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2319                 track->indices[i].offset = unpack_uint64_(buffer, len);
2320
2321                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2322                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2323                 if(read_cb(buffer, 1, len, handle) != len)
2324                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2325                 track->indices[i].number = (FLAC__byte)unpack_uint32_(buffer, len);
2326
2327                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2328                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2329                 if(read_cb(buffer, 1, len, handle) != len)
2330                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2331         }
2332
2333         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2334 }
2335
2336 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet *block)
2337 {
2338         unsigned i, len;
2339         FLAC__Metadata_SimpleIteratorStatus status;
2340         FLAC__byte buffer[1024]; /* MSVC needs a constant expression so we put a magic number and assert */
2341
2342         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN)/8 <= sizeof(buffer));
2343         FLAC__ASSERT(sizeof(FLAC__uint64) <= sizeof(buffer));
2344
2345         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2346         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2347         if(read_cb(block->media_catalog_number, 1, len, handle) != len)
2348                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2349
2350         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2351         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2352         if(read_cb(buffer, 1, len, handle) != len)
2353                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2354         block->lead_in = unpack_uint64_(buffer, len);
2355
2356         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2357         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2358         if(read_cb(buffer, 1, len, handle) != len)
2359                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2360         block->is_cd = buffer[0]&0x80? true : false;
2361
2362         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2363         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2364         if(read_cb(buffer, 1, len, handle) != len)
2365                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2366         block->num_tracks = unpack_uint32_(buffer, len);
2367
2368         if(block->num_tracks == 0) {
2369                 block->tracks = 0;
2370         }
2371         else if(0 == (block->tracks = (FLAC__StreamMetadata_CueSheet_Track*)calloc(block->num_tracks, sizeof(FLAC__StreamMetadata_CueSheet_Track))))
2372                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2373
2374         for(i = 0; i < block->num_tracks; i++) {
2375                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_cuesheet_track_cb_(handle, read_cb, block->tracks + i)))
2376                         return status;
2377         }
2378
2379         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2380 }
2381
2382 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)
2383 {
2384         FLAC__byte buffer[sizeof(FLAC__uint32)];
2385
2386         FLAC__ASSERT(0 != data);
2387         FLAC__ASSERT(length_len%8 == 0);
2388
2389         length_len /= 8; /* convert to bytes */
2390
2391         FLAC__ASSERT(sizeof(buffer) >= length_len);
2392
2393         if(read_cb(buffer, 1, length_len, handle) != length_len)
2394                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2395         *length = unpack_uint32_(buffer, length_len);
2396
2397         if(0 != *data)
2398                 free(*data);
2399
2400         if(0 == (*data = (FLAC__byte*)safe_malloc_add_2op_(*length, /*+*/1)))
2401                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2402
2403         if(*length > 0) {
2404                 if(read_cb(*data, 1, *length, handle) != *length)
2405                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2406         }
2407
2408         (*data)[*length] = '\0';
2409
2410         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2411 }
2412
2413 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Picture *block)
2414 {
2415         FLAC__Metadata_SimpleIteratorStatus status;
2416         FLAC__byte buffer[4]; /* asserted below that this is big enough */
2417         FLAC__uint32 len;
2418
2419         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8);
2420         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8);
2421         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8);
2422         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8);
2423         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8);
2424
2425         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_TYPE_LEN % 8 == 0);
2426         len = FLAC__STREAM_METADATA_PICTURE_TYPE_LEN / 8;
2427         if(read_cb(buffer, 1, len, handle) != len)
2428                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2429         block->type = (FLAC__StreamMetadata_Picture_Type)unpack_uint32_(buffer, len);
2430
2431         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)
2432                 return status;
2433
2434         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)
2435                 return status;
2436
2437         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN % 8 == 0);
2438         len = FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN / 8;
2439         if(read_cb(buffer, 1, len, handle) != len)
2440                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2441         block->width = unpack_uint32_(buffer, len);
2442
2443         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN % 8 == 0);
2444         len = FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN / 8;
2445         if(read_cb(buffer, 1, len, handle) != len)
2446                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2447         block->height = unpack_uint32_(buffer, len);
2448
2449         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN % 8 == 0);
2450         len = FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN / 8;
2451         if(read_cb(buffer, 1, len, handle) != len)
2452                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2453         block->depth = unpack_uint32_(buffer, len);
2454
2455         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_COLORS_LEN % 8 == 0);
2456         len = FLAC__STREAM_METADATA_PICTURE_COLORS_LEN / 8;
2457         if(read_cb(buffer, 1, len, handle) != len)
2458                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2459         block->colors = unpack_uint32_(buffer, len);
2460
2461         /* for convenience we use read_metadata_block_data_picture_cstring_cb_() even though it adds an extra terminating NUL we don't use */
2462         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)
2463                 return status;
2464
2465         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2466 }
2467
2468 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2469 {
2470         if(block_length == 0) {
2471                 block->data = 0;
2472         }
2473         else {
2474                 if(0 == (block->data = (FLAC__byte*)malloc(block_length)))
2475                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2476
2477                 if(read_cb(block->data, 1, block_length, handle) != block_length)
2478                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2479         }
2480
2481         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2482 }
2483
2484 FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2485 {
2486         FLAC__ASSERT(0 != file);
2487         FLAC__ASSERT(0 != status);
2488
2489         if(!write_metadata_block_header_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2490                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2491                 return false;
2492         }
2493
2494         return true;
2495 }
2496
2497 FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2498 {
2499         FLAC__ASSERT(0 != file);
2500         FLAC__ASSERT(0 != status);
2501
2502         if (write_metadata_block_data_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2503                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2504                 return true;
2505         }
2506         else {
2507                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2508                 return false;
2509         }
2510 }
2511
2512 FLAC__bool write_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2513 {
2514         FLAC__byte buffer[FLAC__STREAM_METADATA_HEADER_LENGTH];
2515
2516         FLAC__ASSERT(block->length < (1u << FLAC__STREAM_METADATA_LENGTH_LEN));
2517
2518         buffer[0] = (block->is_last? 0x80 : 0) | (FLAC__byte)block->type;
2519         pack_uint32_(block->length, buffer + 1, 3);
2520
2521         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
2522                 return false;
2523
2524         return true;
2525 }
2526
2527 FLAC__bool write_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2528 {
2529         FLAC__ASSERT(0 != block);
2530
2531         switch(block->type) {
2532                 case FLAC__METADATA_TYPE_STREAMINFO:
2533                         return write_metadata_block_data_streaminfo_cb_(handle, write_cb, &block->data.stream_info);
2534                 case FLAC__METADATA_TYPE_PADDING:
2535                         return write_metadata_block_data_padding_cb_(handle, write_cb, &block->data.padding, block->length);
2536                 case FLAC__METADATA_TYPE_APPLICATION:
2537                         return write_metadata_block_data_application_cb_(handle, write_cb, &block->data.application, block->length);
2538                 case FLAC__METADATA_TYPE_SEEKTABLE:
2539                         return write_metadata_block_data_seektable_cb_(handle, write_cb, &block->data.seek_table);
2540                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
2541                         return write_metadata_block_data_vorbis_comment_cb_(handle, write_cb, &block->data.vorbis_comment);
2542                 case FLAC__METADATA_TYPE_CUESHEET:
2543                         return write_metadata_block_data_cuesheet_cb_(handle, write_cb, &block->data.cue_sheet);
2544                 case FLAC__METADATA_TYPE_PICTURE:
2545                         return write_metadata_block_data_picture_cb_(handle, write_cb, &block->data.picture);
2546                 default:
2547                         return write_metadata_block_data_unknown_cb_(handle, write_cb, &block->data.unknown, block->length);
2548         }
2549 }
2550
2551 FLAC__bool write_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_StreamInfo *block)
2552 {
2553         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH];
2554         const unsigned channels1 = block->channels - 1;
2555         const unsigned bps1 = block->bits_per_sample - 1;
2556
2557         /* we are using hardcoded numbers for simplicity but we should
2558          * probably eventually write a bit-level packer and use the
2559          * _STREAMINFO_ constants.
2560          */
2561         pack_uint32_(block->min_blocksize, buffer, 2);
2562         pack_uint32_(block->max_blocksize, buffer+2, 2);
2563         pack_uint32_(block->min_framesize, buffer+4, 3);
2564         pack_uint32_(block->max_framesize, buffer+7, 3);
2565         buffer[10] = (block->sample_rate >> 12) & 0xff;
2566         buffer[11] = (block->sample_rate >> 4) & 0xff;
2567         buffer[12] = ((block->sample_rate & 0x0f) << 4) | (channels1 << 1) | (bps1 >> 4);
2568         buffer[13] = (FLAC__byte)(((bps1 & 0x0f) << 4) | ((block->total_samples >> 32) & 0x0f));
2569         pack_uint32_((FLAC__uint32)block->total_samples, buffer+14, 4);
2570         memcpy(buffer+18, block->md5sum, 16);
2571
2572         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
2573                 return false;
2574
2575         return true;
2576 }
2577
2578 FLAC__bool write_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Padding *block, unsigned block_length)
2579 {
2580         unsigned i, n = block_length;
2581         FLAC__byte buffer[1024];
2582
2583         (void)block;
2584
2585         memset(buffer, 0, 1024);
2586
2587         for(i = 0; i < n/1024; i++)
2588                 if(write_cb(buffer, 1, 1024, handle) != 1024)
2589                         return false;
2590
2591         n %= 1024;
2592
2593         if(write_cb(buffer, 1, n, handle) != n)
2594                 return false;
2595
2596         return true;
2597 }
2598
2599 FLAC__bool write_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Application *block, unsigned block_length)
2600 {
2601         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
2602
2603         if(write_cb(block->id, 1, id_bytes, handle) != id_bytes)
2604                 return false;
2605
2606         block_length -= id_bytes;
2607
2608         if(write_cb(block->data, 1, block_length, handle) != block_length)
2609                 return false;
2610
2611         return true;
2612 }
2613
2614 FLAC__bool write_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_SeekTable *block)
2615 {
2616         unsigned i;
2617         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
2618
2619         for(i = 0; i < block->num_points; i++) {
2620                 /* some MAGIC NUMBERs here */
2621                 pack_uint64_(block->points[i].sample_number, buffer, 8);
2622                 pack_uint64_(block->points[i].stream_offset, buffer+8, 8);
2623                 pack_uint32_(block->points[i].frame_samples, buffer+16, 2);
2624                 if(write_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
2625                         return false;
2626         }
2627
2628         return true;
2629 }
2630
2631 FLAC__bool write_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_VorbisComment *block)
2632 {
2633         unsigned i;
2634         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
2635         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2636         FLAC__byte buffer[4]; /* magic number is asserted below */
2637
2638         FLAC__ASSERT(max(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN, FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN) / 8 == sizeof(buffer));
2639
2640         pack_uint32_little_endian_(block->vendor_string.length, buffer, entry_length_len);
2641         if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2642                 return false;
2643         if(write_cb(block->vendor_string.entry, 1, block->vendor_string.length, handle) != block->vendor_string.length)
2644                 return false;
2645
2646         pack_uint32_little_endian_(block->num_comments, buffer, num_comments_len);
2647         if(write_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2648                 return false;
2649
2650         for(i = 0; i < block->num_comments; i++) {
2651                 pack_uint32_little_endian_(block->comments[i].length, buffer, entry_length_len);
2652                 if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2653                         return false;
2654                 if(write_cb(block->comments[i].entry, 1, block->comments[i].length, handle) != block->comments[i].length)
2655                         return false;
2656         }
2657
2658         return true;
2659 }
2660
2661 FLAC__bool write_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_CueSheet *block)
2662 {
2663         unsigned i, j, len;
2664         FLAC__byte buffer[1024]; /* asserted below that this is big enough */
2665
2666         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2667         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN/8);
2668         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);
2669         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2670
2671         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2672         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2673         if(write_cb(block->media_catalog_number, 1, len, handle) != len)
2674                 return false;
2675
2676         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2677         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2678         pack_uint64_(block->lead_in, buffer, len);
2679         if(write_cb(buffer, 1, len, handle) != len)
2680                 return false;
2681
2682         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2683         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2684         memset(buffer, 0, len);
2685         if(block->is_cd)
2686                 buffer[0] |= 0x80;
2687         if(write_cb(buffer, 1, len, handle) != len)
2688                 return false;
2689
2690         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2691         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2692         pack_uint32_(block->num_tracks, buffer, len);
2693         if(write_cb(buffer, 1, len, handle) != len)
2694                 return false;
2695
2696         for(i = 0; i < block->num_tracks; i++) {
2697                 FLAC__StreamMetadata_CueSheet_Track *track = block->tracks + i;
2698
2699                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2700                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2701                 pack_uint64_(track->offset, buffer, len);
2702                 if(write_cb(buffer, 1, len, handle) != len)
2703                         return false;
2704
2705                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2706                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2707                 pack_uint32_(track->number, buffer, len);
2708                 if(write_cb(buffer, 1, len, handle) != len)
2709                         return false;
2710
2711                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2712                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2713                 if(write_cb(track->isrc, 1, len, handle) != len)
2714                         return false;
2715
2716                 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);
2717                 len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2718                 memset(buffer, 0, len);
2719                 buffer[0] = (track->type << 7) | (track->pre_emphasis << 6);
2720                 if(write_cb(buffer, 1, len, handle) != len)
2721                         return false;
2722
2723                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2724                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2725                 pack_uint32_(track->num_indices, buffer, len);
2726                 if(write_cb(buffer, 1, len, handle) != len)
2727                         return false;
2728
2729                 for(j = 0; j < track->num_indices; j++) {
2730                         FLAC__StreamMetadata_CueSheet_Index *index = track->indices + j;
2731
2732                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2733                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2734                         pack_uint64_(index->offset, buffer, len);
2735                         if(write_cb(buffer, 1, len, handle) != len)
2736                                 return false;
2737
2738                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2739                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2740                         pack_uint32_(index->number, buffer, len);
2741                         if(write_cb(buffer, 1, len, handle) != len)
2742                                 return false;
2743
2744                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2745                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2746                         memset(buffer, 0, len);
2747                         if(write_cb(buffer, 1, len, handle) != len)
2748                                 return false;
2749                 }
2750         }
2751
2752         return true;
2753 }
2754
2755 FLAC__bool write_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Picture *block)
2756 {
2757         unsigned len;
2758         size_t slen;
2759         FLAC__byte buffer[4]; /* magic number is asserted below */
2760
2761         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_TYPE_LEN%8);
2762         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN%8);
2763         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN%8);
2764         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN%8);
2765         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN%8);
2766         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN%8);
2767         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_COLORS_LEN%8);
2768         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN%8);
2769         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8);
2770         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN/8);
2771         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN/8);
2772         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8);
2773         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8);
2774         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8);
2775         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8);
2776         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN/8);
2777
2778         len = FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8;
2779         pack_uint32_(block->type, buffer, len);
2780         if(write_cb(buffer, 1, len, handle) != len)
2781                 return false;
2782
2783         len = FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN/8;
2784         slen = strlen(block->mime_type);
2785         pack_uint32_(slen, buffer, len);
2786         if(write_cb(buffer, 1, len, handle) != len)
2787                 return false;
2788         if(write_cb(block->mime_type, 1, slen, handle) != slen)
2789                 return false;
2790
2791         len = FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN/8;
2792         slen = strlen((const char *)block->description);
2793         pack_uint32_(slen, buffer, len);
2794         if(write_cb(buffer, 1, len, handle) != len)
2795                 return false;
2796         if(write_cb(block->description, 1, slen, handle) != slen)
2797                 return false;
2798
2799         len = FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8;
2800         pack_uint32_(block->width, buffer, len);
2801         if(write_cb(buffer, 1, len, handle) != len)
2802                 return false;
2803
2804         len = FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8;
2805         pack_uint32_(block->height, buffer, len);
2806         if(write_cb(buffer, 1, len, handle) != len)
2807                 return false;
2808
2809         len = FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8;
2810         pack_uint32_(block->depth, buffer, len);
2811         if(write_cb(buffer, 1, len, handle) != len)
2812                 return false;
2813
2814         len = FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8;
2815         pack_uint32_(block->colors, buffer, len);
2816         if(write_cb(buffer, 1, len, handle) != len)
2817                 return false;
2818
2819         len = FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN/8;
2820         pack_uint32_(block->data_length, buffer, len);
2821         if(write_cb(buffer, 1, len, handle) != len)
2822                 return false;
2823         if(write_cb(block->data, 1, block->data_length, handle) != block->data_length)
2824                 return false;
2825
2826         return true;
2827 }
2828
2829 FLAC__bool write_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2830 {
2831         if(write_cb(block->data, 1, block_length, handle) != block_length)
2832                 return false;
2833
2834         return true;
2835 }
2836
2837 FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block)
2838 {
2839         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2840                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2841                 return false;
2842         }
2843
2844         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2845                 return false;
2846
2847         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2848                 return false;
2849
2850         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2851                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2852                 return false;
2853         }
2854
2855         return read_metadata_block_header_(iterator);
2856 }
2857
2858 FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last)
2859 {
2860         FLAC__StreamMetadata *padding;
2861
2862         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2863                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2864                 return false;
2865         }
2866
2867         block->is_last = false;
2868
2869         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2870                 return false;
2871
2872         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2873                 return false;
2874
2875         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING)))
2876                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2877
2878         padding->is_last = padding_is_last;
2879         padding->length = padding_length;
2880
2881         if(!write_metadata_block_header_(iterator->file, &iterator->status, padding)) {
2882                 FLAC__metadata_object_delete(padding);
2883                 return false;
2884         }
2885
2886         if(!write_metadata_block_data_(iterator->file, &iterator->status, padding)) {
2887                 FLAC__metadata_object_delete(padding);
2888                 return false;
2889         }
2890
2891         FLAC__metadata_object_delete(padding);
2892
2893         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2894                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2895                 return false;
2896         }
2897
2898         return read_metadata_block_header_(iterator);
2899 }
2900
2901 FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append)
2902 {
2903         FILE *tempfile;
2904         char *tempfilename;
2905         int fixup_is_last_code = 0; /* 0 => no need to change any is_last flags */
2906         off_t fixup_is_last_flag_offset = -1;
2907
2908         FLAC__ASSERT(0 != block || append == false);
2909
2910         if(iterator->is_last) {
2911                 if(append) {
2912                         fixup_is_last_code = 1; /* 1 => clear the is_last flag at the following offset */
2913                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2914                 }
2915                 else if(0 == block) {
2916                         simple_iterator_push_(iterator);
2917                         if(!FLAC__metadata_simple_iterator_prev(iterator)) {
2918                                 (void)simple_iterator_pop_(iterator);
2919                                 return false;
2920                         }
2921                         fixup_is_last_code = -1; /* -1 => set the is_last the flag at the following offset */
2922                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2923                         if(!simple_iterator_pop_(iterator))
2924                                 return false;
2925                 }
2926         }
2927
2928         if(!simple_iterator_copy_file_prefix_(iterator, &tempfile, &tempfilename, append))
2929                 return false;
2930
2931         if(0 != block) {
2932                 if(!write_metadata_block_header_(tempfile, &iterator->status, block)) {
2933                         cleanup_tempfile_(&tempfile, &tempfilename);
2934                         return false;
2935                 }
2936
2937                 if(!write_metadata_block_data_(tempfile, &iterator->status, block)) {
2938                         cleanup_tempfile_(&tempfile, &tempfilename);
2939                         return false;
2940                 }
2941         }
2942
2943         if(!simple_iterator_copy_file_postfix_(iterator, &tempfile, &tempfilename, fixup_is_last_code, fixup_is_last_flag_offset, block==0))
2944                 return false;
2945
2946         if(append)
2947                 return FLAC__metadata_simple_iterator_next(iterator);
2948
2949         return true;
2950 }
2951
2952 void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator)
2953 {
2954         FLAC__ASSERT(iterator->depth+1 < SIMPLE_ITERATOR_MAX_PUSH_DEPTH);
2955         iterator->offset[iterator->depth+1] = iterator->offset[iterator->depth];
2956         iterator->depth++;
2957 }
2958
2959 FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator)
2960 {
2961         FLAC__ASSERT(iterator->depth > 0);
2962         iterator->depth--;
2963         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2964                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2965                 return false;
2966         }
2967
2968         return read_metadata_block_header_(iterator);
2969 }
2970
2971 /* return meanings:
2972  * 0: ok
2973  * 1: read error
2974  * 2: seek error
2975  * 3: not a FLAC file
2976  */
2977 unsigned seek_to_first_metadata_block_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb)
2978 {
2979         FLAC__byte buffer[4];
2980         size_t n;
2981         unsigned i;
2982
2983         FLAC__ASSERT(FLAC__STREAM_SYNC_LENGTH == sizeof(buffer));
2984
2985         /* skip any id3v2 tag */
2986         errno = 0;
2987         n = read_cb(buffer, 1, 4, handle);
2988         if(errno)
2989                 return 1;
2990         else if(n != 4)
2991                 return 3;
2992         else if(0 == memcmp(buffer, "ID3", 3)) {
2993                 unsigned tag_length = 0;
2994
2995                 /* skip to the tag length */
2996                 if(seek_cb(handle, 2, SEEK_CUR) < 0)
2997                         return 2;
2998
2999                 /* read the length */
3000                 for(i = 0; i < 4; i++) {
3001                         if(read_cb(buffer, 1, 1, handle) < 1 || buffer[0] & 0x80)
3002                                 return 1;
3003                         tag_length <<= 7;
3004                         tag_length |= (buffer[0] & 0x7f);
3005                 }
3006
3007                 /* skip the rest of the tag */
3008                 if(seek_cb(handle, tag_length, SEEK_CUR) < 0)
3009                         return 2;
3010
3011                 /* read the stream sync code */
3012                 errno = 0;
3013                 n = read_cb(buffer, 1, 4, handle);
3014                 if(errno)
3015                         return 1;
3016                 else if(n != 4)
3017                         return 3;
3018         }
3019
3020         /* check for the fLaC signature */
3021         if(0 == memcmp(FLAC__STREAM_SYNC_STRING, buffer, FLAC__STREAM_SYNC_LENGTH))
3022                 return 0;
3023         else
3024                 return 3;
3025 }
3026
3027 unsigned seek_to_first_metadata_block_(FILE *f)
3028 {
3029         return seek_to_first_metadata_block_cb_((FLAC__IOHandle)f, (FLAC__IOCallback_Read)fread, fseek_wrapper_);
3030 }
3031
3032 FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append)
3033 {
3034         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];
3035
3036         if(0 != fseeko(iterator->file, 0, SEEK_SET)) {
3037                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3038                 return false;
3039         }
3040         if(!open_tempfile_(iterator->filename, iterator->tempfile_path_prefix, tempfile, tempfilename, &iterator->status)) {
3041                 cleanup_tempfile_(tempfile, tempfilename);
3042                 return false;
3043         }
3044         if(!copy_n_bytes_from_file_(iterator->file, *tempfile, offset_end, &iterator->status)) {
3045                 cleanup_tempfile_(tempfile, tempfilename);
3046                 return false;
3047         }
3048
3049         return true;
3050 }
3051
3052 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)
3053 {
3054         off_t save_offset = iterator->offset[iterator->depth];
3055         FLAC__ASSERT(0 != *tempfile);
3056
3057         if(0 != fseeko(iterator->file, save_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length, SEEK_SET)) {
3058                 cleanup_tempfile_(tempfile, tempfilename);
3059                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3060                 return false;
3061         }
3062         if(!copy_remaining_bytes_from_file_(iterator->file, *tempfile, &iterator->status)) {
3063                 cleanup_tempfile_(tempfile, tempfilename);
3064                 return false;
3065         }
3066
3067         if(fixup_is_last_code != 0) {
3068                 /*
3069                  * if code == 1, it means a block was appended to the end so
3070                  *   we have to clear the is_last flag of the previous block
3071                  * if code == -1, it means the last block was deleted so
3072                  *   we have to set the is_last flag of the previous block
3073                  */
3074                 /* MAGIC NUMBERs here; we know the is_last flag is the high bit of the byte at this location */
3075                 FLAC__byte x;
3076                 if(0 != fseeko(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
3077                         cleanup_tempfile_(tempfile, tempfilename);
3078                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3079                         return false;
3080                 }
3081                 if(fread(&x, 1, 1, *tempfile) != 1) {
3082                         cleanup_tempfile_(tempfile, tempfilename);
3083                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3084                         return false;
3085                 }
3086                 if(fixup_is_last_code > 0) {
3087                         FLAC__ASSERT(x & 0x80);
3088                         x &= 0x7f;
3089                 }
3090                 else {
3091                         FLAC__ASSERT(!(x & 0x80));
3092                         x |= 0x80;
3093                 }
3094                 if(0 != fseeko(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
3095                         cleanup_tempfile_(tempfile, tempfilename);
3096                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3097                         return false;
3098                 }
3099                 if(local__fwrite(&x, 1, 1, *tempfile) != 1) {
3100                         cleanup_tempfile_(tempfile, tempfilename);
3101                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3102                         return false;
3103                 }
3104         }
3105
3106         (void)fclose(iterator->file);
3107
3108         if(!transport_tempfile_(iterator->filename, tempfile, tempfilename, &iterator->status))
3109                 return false;
3110
3111         if(iterator->has_stats)
3112                 set_file_stats_(iterator->filename, &iterator->stats);
3113
3114         if(!simple_iterator_prime_input_(iterator, !iterator->is_writable))
3115                 return false;
3116         if(backup) {
3117                 while(iterator->offset[iterator->depth] + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length < save_offset)
3118                         if(!FLAC__metadata_simple_iterator_next(iterator))
3119                                 return false;
3120                 return true;
3121         }
3122         else {
3123                 /* move the iterator to it's original block faster by faking a push, then doing a pop_ */
3124                 FLAC__ASSERT(iterator->depth == 0);
3125                 iterator->offset[0] = save_offset;
3126                 iterator->depth++;
3127                 return simple_iterator_pop_(iterator);
3128         }
3129 }
3130
3131 FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status)
3132 {
3133         FLAC__byte buffer[8192];
3134         size_t n;
3135
3136         FLAC__ASSERT(bytes >= 0);
3137         while(bytes > 0) {
3138                 n = min(sizeof(buffer), (size_t)bytes);
3139                 if(fread(buffer, 1, n, file) != n) {
3140                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3141                         return false;
3142                 }
3143                 if(local__fwrite(buffer, 1, n, tempfile) != n) {
3144                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3145                         return false;
3146                 }
3147                 bytes -= n;
3148         }
3149
3150         return true;
3151 }
3152
3153 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)
3154 {
3155         FLAC__byte buffer[8192];
3156         size_t n;
3157
3158         FLAC__ASSERT(bytes >= 0);
3159         while(bytes > 0) {
3160                 n = min(sizeof(buffer), (size_t)bytes);
3161                 if(read_cb(buffer, 1, n, handle) != n) {
3162                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3163                         return false;
3164                 }
3165                 if(temp_write_cb(buffer, 1, n, temp_handle) != n) {
3166                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3167                         return false;
3168                 }
3169                 bytes -= n;
3170         }
3171
3172         return true;
3173 }
3174
3175 FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status)
3176 {
3177         FLAC__byte buffer[8192];
3178         size_t n;
3179
3180         while(!feof(file)) {
3181                 n = fread(buffer, 1, sizeof(buffer), file);
3182                 if(n == 0 && !feof(file)) {
3183                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3184                         return false;
3185                 }
3186                 if(n > 0 && local__fwrite(buffer, 1, n, tempfile) != n) {
3187                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3188                         return false;
3189                 }
3190         }
3191
3192         return true;
3193 }
3194
3195 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)
3196 {
3197         FLAC__byte buffer[8192];
3198         size_t n;
3199
3200         while(!eof_cb(handle)) {
3201                 n = read_cb(buffer, 1, sizeof(buffer), handle);
3202                 if(n == 0 && !eof_cb(handle)) {
3203                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3204                         return false;
3205                 }
3206                 if(n > 0 && temp_write_cb(buffer, 1, n, temp_handle) != n) {
3207                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3208                         return false;
3209                 }
3210         }
3211
3212         return true;
3213 }
3214
3215 FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
3216 {
3217         static const char *tempfile_suffix = ".metadata_edit";
3218         if(0 == tempfile_path_prefix) {
3219                 if(0 == (*tempfilename = (char*)safe_malloc_add_3op_(strlen(filename), /*+*/strlen(tempfile_suffix), /*+*/1))) {
3220                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
3221                         return false;
3222                 }
3223                 strcpy(*tempfilename, filename);
3224                 strcat(*tempfilename, tempfile_suffix);
3225         }
3226         else {
3227                 const char *p = strrchr(filename, '/');
3228                 if(0 == p)
3229                         p = filename;
3230                 else
3231                         p++;
3232
3233                 if(0 == (*tempfilename = (char*)safe_malloc_add_4op_(strlen(tempfile_path_prefix), /*+*/strlen(p), /*+*/strlen(tempfile_suffix), /*+*/2))) {
3234                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
3235                         return false;
3236                 }
3237                 strcpy(*tempfilename, tempfile_path_prefix);
3238                 strcat(*tempfilename, "/");
3239                 strcat(*tempfilename, p);
3240                 strcat(*tempfilename, tempfile_suffix);
3241         }
3242
3243         if(0 == (*tempfile = fopen(*tempfilename, "w+b"))) {
3244                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
3245                 return false;
3246         }
3247
3248         return true;
3249 }
3250
3251 FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
3252 {
3253         FLAC__ASSERT(0 != filename);
3254         FLAC__ASSERT(0 != tempfile);
3255         FLAC__ASSERT(0 != *tempfile);
3256         FLAC__ASSERT(0 != tempfilename);
3257         FLAC__ASSERT(0 != *tempfilename);
3258         FLAC__ASSERT(0 != status);
3259
3260         (void)fclose(*tempfile);
3261         *tempfile = 0;
3262
3263 #if defined _MSC_VER || defined __BORLANDC__ || defined __MINGW32__ || defined __EMX__
3264         /* on some flavors of windows, rename() will fail if the destination already exists */
3265         if(unlink(filename) < 0) {
3266                 cleanup_tempfile_(tempfile, tempfilename);
3267                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR;
3268                 return false;
3269         }
3270 #endif
3271
3272         /*@@@ to fully support the tempfile_path_prefix we need to update this piece to actually copy across filesystems instead of just rename(): */
3273         if(0 != rename(*tempfilename, filename)) {
3274                 cleanup_tempfile_(tempfile, tempfilename);
3275                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR;
3276                 return false;
3277         }
3278
3279         cleanup_tempfile_(tempfile, tempfilename);
3280
3281         return true;
3282 }
3283
3284 void cleanup_tempfile_(FILE **tempfile, char **tempfilename)
3285 {
3286         if(0 != *tempfile) {
3287                 (void)fclose(*tempfile);
3288                 *tempfile = 0;
3289         }
3290
3291         if(0 != *tempfilename) {
3292                 (void)unlink(*tempfilename);
3293                 free(*tempfilename);
3294                 *tempfilename = 0;
3295         }
3296 }
3297
3298 FLAC__bool get_file_stats_(const char *filename, struct stat *stats)
3299 {
3300         FLAC__ASSERT(0 != filename);
3301         FLAC__ASSERT(0 != stats);
3302         return (0 == stat(filename, stats));
3303 }
3304
3305 void set_file_stats_(const char *filename, struct stat *stats)
3306 {
3307         struct utimbuf srctime;
3308
3309         FLAC__ASSERT(0 != filename);
3310         FLAC__ASSERT(0 != stats);
3311
3312         srctime.actime = stats->st_atime;
3313         srctime.modtime = stats->st_mtime;
3314         (void)chmod(filename, stats->st_mode);
3315         (void)utime(filename, &srctime);
3316 #if !defined _MSC_VER && !defined __BORLANDC__ && !defined __MINGW32__ && !defined __EMX__
3317         (void)chown(filename, stats->st_uid, -1);
3318         (void)chown(filename, -1, stats->st_gid);
3319 #endif
3320 }
3321
3322 int fseek_wrapper_(FLAC__IOHandle handle, FLAC__int64 offset, int whence)
3323 {
3324         return fseeko((FILE*)handle, (off_t)offset, whence);
3325 }
3326
3327 FLAC__int64 ftell_wrapper_(FLAC__IOHandle handle)
3328 {
3329         return ftello((FILE*)handle);
3330 }
3331
3332 FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status)
3333 {
3334         switch(status) {
3335                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK:
3336                         return FLAC__METADATA_CHAIN_STATUS_OK;
3337                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT:
3338                         return FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT;
3339                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE:
3340                         return FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
3341                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE:
3342                         return FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE;
3343                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE:
3344                         return FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE;
3345                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA:
3346                         return FLAC__METADATA_CHAIN_STATUS_BAD_METADATA;
3347                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR:
3348                         return FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
3349                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR:
3350                         return FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
3351                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR:
3352                         return FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
3353                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR:
3354                         return FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR;
3355                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR:
3356                         return FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR;
3357                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR:
3358                         return FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
3359                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR:
3360                 default:
3361                         return FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
3362         }
3363 }