src/libFLAC/metadata_iterators.c

   1 /* libFLAC - Free Lossless Audio Codec library
   2  * Copyright (C) 2001,2002,2003,2004,2005,2006,2007,2008,2009  Josh Coalson
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  * - Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *
  11  * - Redistributions in binary form must reproduce the above copyright
  12  * notice, this list of conditions and the following disclaimer in the
  13  * documentation and/or other materials provided with the distribution.
  14  *
  15  * - Neither the name of the Xiph.org Foundation nor the names of its
  16  * contributors may be used to endorse or promote products derived from
  17  * this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  22  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
  23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  26  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  27  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  28  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  29  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 #if HAVE_CONFIG_H
  33 #  include <config.h>
  34 #endif
  35
  36 #include <errno.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40
  41 #if defined _MSC_VER || defined __BORLANDC__ || defined __MINGW32__
  42 #if defined __BORLANDC__
  43 #include <utime.h> /* for utime() */
  44 #else
  45 #include <sys/utime.h> /* for utime() */
  46 #endif
  47 #include <io.h> /* for chmod() */
  48 #include <sys/types.h> /* for off_t */
  49 #if _MSC_VER <= 1600 || defined __BORLANDC__ /* @@@ [2G limit] */
  50 #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                                 node_delete_(node);
1221                                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1222                                 return false;
1223                         }
1224
1225                         node->data = FLAC__metadata_object_new(type);
1226                         if(0 == node->data) {
1227                                 node_delete_(node);
1228                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1229                                 return false;
1230                         }
1231
1232                         node->data->is_last = is_last;
1233                         node->data->length = length;
1234
1235                         chain->status = get_equivalent_status_(read_metadata_block_data_cb_(handle, read_cb, seek_cb, node->data));
1236                         if(chain->status != FLAC__METADATA_CHAIN_STATUS_OK) {
1237                                 node_delete_(node);
1238                                 return false;
1239                         }
1240                         chain_append_node_(chain, node);
1241                 } while(!is_last);
1242         }
1243
1244         {
1245                 FLAC__int64 pos = tell_cb(handle);
1246                 if(pos < 0) {
1247                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1248                         return false;
1249                 }
1250                 chain->last_offset = (off_t)pos;
1251         }
1252
1253         chain->initial_length = chain_calculate_length_(chain);
1254
1255         return true;
1256 }
1257
1258 static FLAC__StreamDecoderReadStatus chain_read_ogg_read_cb_(const FLAC__StreamDecoder *decoder, FLAC__byte buffer[], size_t *bytes, void *client_data)
1259 {
1260         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1261         (void)decoder;
1262         if(*bytes > 0 && chain->status == FLAC__METADATA_CHAIN_STATUS_OK) {
1263                 *bytes = chain->read_cb(buffer, sizeof(FLAC__byte), *bytes, chain->handle);
1264                 if(*bytes == 0)
1265                         return FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM;
1266                 else
1267                         return FLAC__STREAM_DECODER_READ_STATUS_CONTINUE;
1268         }
1269         else
1270                 return FLAC__STREAM_DECODER_READ_STATUS_ABORT;
1271 }
1272
1273 static FLAC__StreamDecoderWriteStatus chain_read_ogg_write_cb_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
1274 {
1275         (void)decoder, (void)frame, (void)buffer, (void)client_data;
1276         return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
1277 }
1278
1279 static void chain_read_ogg_metadata_cb_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
1280 {
1281         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1282         FLAC__Metadata_Node *node;
1283
1284         (void)decoder;
1285
1286         node = node_new_();
1287         if(0 == node) {
1288                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1289                 return;
1290         }
1291
1292         node->data = FLAC__metadata_object_clone(metadata);
1293         if(0 == node->data) {
1294                 node_delete_(node);
1295                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1296                 return;
1297         }
1298
1299         chain_append_node_(chain, node);
1300 }
1301
1302 static void chain_read_ogg_error_cb_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
1303 {
1304         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1305         (void)decoder, (void)status;
1306         chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1307 }
1308
1309 static FLAC__bool chain_read_ogg_cb_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb)
1310 {
1311         FLAC__StreamDecoder *decoder;
1312
1313         FLAC__ASSERT(0 != chain);
1314
1315         /* we assume we're already at the beginning of the file */
1316
1317         chain->handle = handle;
1318         chain->read_cb = read_cb;
1319         if(0 == (decoder = FLAC__stream_decoder_new())) {
1320                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1321                 return false;
1322         }
1323         FLAC__stream_decoder_set_metadata_respond_all(decoder);
1324         if(FLAC__stream_decoder_init_ogg_stream(decoder, chain_read_ogg_read_cb_, /*seek_callback=*/0, /*tell_callback=*/0, /*length_callback=*/0, /*eof_callback=*/0, chain_read_ogg_write_cb_, chain_read_ogg_metadata_cb_, chain_read_ogg_error_cb_, chain) != FLAC__STREAM_DECODER_INIT_STATUS_OK) {
1325                 FLAC__stream_decoder_delete(decoder);
1326                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1327                 return false;
1328         }
1329
1330         chain->first_offset = 0; /*@@@ wrong; will need to be set correctly to implement metadata writing for Ogg FLAC */
1331
1332         if(!FLAC__stream_decoder_process_until_end_of_metadata(decoder))
1333                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1334         if(chain->status != FLAC__METADATA_CHAIN_STATUS_OK) {
1335                 FLAC__stream_decoder_delete(decoder);
1336                 return false;
1337         }
1338
1339         FLAC__stream_decoder_delete(decoder);
1340
1341         chain->last_offset = 0; /*@@@ wrong; will need to be set correctly to implement metadata writing for Ogg FLAC */
1342
1343         chain->initial_length = chain_calculate_length_(chain);
1344
1345         return true;
1346 }
1347
1348 static FLAC__bool chain_rewrite_metadata_in_place_cb_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, FLAC__IOCallback_Seek seek_cb)
1349 {
1350         FLAC__Metadata_Node *node;
1351
1352         FLAC__ASSERT(0 != chain);
1353         FLAC__ASSERT(0 != chain->head);
1354
1355         if(0 != seek_cb(handle, chain->first_offset, SEEK_SET)) {
1356                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1357                 return false;
1358         }
1359
1360         for(node = chain->head; node; node = node->next) {
1361                 if(!write_metadata_block_header_cb_(handle, write_cb, node->data)) {
1362                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1363                         return false;
1364                 }
1365                 if(!write_metadata_block_data_cb_(handle, write_cb, node->data)) {
1366                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1367                         return false;
1368                 }
1369         }
1370
1371         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1372
1373         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
1374         return true;
1375 }
1376
1377 static FLAC__bool chain_rewrite_metadata_in_place_(FLAC__Metadata_Chain *chain)
1378 {
1379         FILE *file;
1380         FLAC__bool ret;
1381
1382         FLAC__ASSERT(0 != chain->filename);
1383
1384         if(0 == (file = fopen(chain->filename, "r+b"))) {
1385                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1386                 return false;
1387         }
1388
1389         /* chain_rewrite_metadata_in_place_cb_() sets chain->status for us */
1390         ret = chain_rewrite_metadata_in_place_cb_(chain, (FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, fseek_wrapper_);
1391
1392         fclose(file);
1393
1394         return ret;
1395 }
1396
1397 static FLAC__bool chain_rewrite_file_(FLAC__Metadata_Chain *chain, const char *tempfile_path_prefix)
1398 {
1399         FILE *f, *tempfile;
1400         char *tempfilename;
1401         FLAC__Metadata_SimpleIteratorStatus status;
1402         const FLAC__Metadata_Node *node;
1403
1404         FLAC__ASSERT(0 != chain);
1405         FLAC__ASSERT(0 != chain->filename);
1406         FLAC__ASSERT(0 != chain->head);
1407
1408         /* copy the file prefix (data up to first metadata block */
1409         if(0 == (f = fopen(chain->filename, "rb"))) {
1410                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1411                 return false;
1412         }
1413         if(!open_tempfile_(chain->filename, tempfile_path_prefix, &tempfile, &tempfilename, &status)) {
1414                 chain->status = get_equivalent_status_(status);
1415                 goto err;
1416         }
1417         if(!copy_n_bytes_from_file_(f, tempfile, chain->first_offset, &status)) {
1418                 chain->status = get_equivalent_status_(status);
1419                 goto err;
1420         }
1421
1422         /* write the metadata */
1423         for(node = chain->head; node; node = node->next) {
1424                 if(!write_metadata_block_header_(tempfile, &status, node->data)) {
1425                         chain->status = get_equivalent_status_(status);
1426                         goto err;
1427                 }
1428                 if(!write_metadata_block_data_(tempfile, &status, node->data)) {
1429                         chain->status = get_equivalent_status_(status);
1430                         goto err;
1431                 }
1432         }
1433         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1434
1435         /* copy the file postfix (everything after the metadata) */
1436         if(0 != fseeko(f, chain->last_offset, SEEK_SET)) {
1437                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1438                 goto err;
1439         }
1440         if(!copy_remaining_bytes_from_file_(f, tempfile, &status)) {
1441                 chain->status = get_equivalent_status_(status);
1442                 goto err;
1443         }
1444
1445         /* move the tempfile on top of the original */
1446         (void)fclose(f);
1447         if(!transport_tempfile_(chain->filename, &tempfile, &tempfilename, &status))
1448                 return false;
1449
1450         return true;
1451
1452 err:
1453         (void)fclose(f);
1454         cleanup_tempfile_(&tempfile, &tempfilename);
1455         return false;
1456 }
1457
1458 /* assumes 'handle' is already at beginning of file */
1459 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)
1460 {
1461         FLAC__Metadata_SimpleIteratorStatus status;
1462         const FLAC__Metadata_Node *node;
1463
1464         FLAC__ASSERT(0 != chain);
1465         FLAC__ASSERT(0 == chain->filename);
1466         FLAC__ASSERT(0 != chain->head);
1467
1468         /* copy the file prefix (data up to first metadata block */
1469         if(!copy_n_bytes_from_file_cb_(handle, read_cb, temp_handle, temp_write_cb, chain->first_offset, &status)) {
1470                 chain->status = get_equivalent_status_(status);
1471                 return false;
1472         }
1473
1474         /* write the metadata */
1475         for(node = chain->head; node; node = node->next) {
1476                 if(!write_metadata_block_header_cb_(temp_handle, temp_write_cb, node->data)) {
1477                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1478                         return false;
1479                 }
1480                 if(!write_metadata_block_data_cb_(temp_handle, temp_write_cb, node->data)) {
1481                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1482                         return false;
1483                 }
1484         }
1485         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1486
1487         /* copy the file postfix (everything after the metadata) */
1488         if(0 != seek_cb(handle, chain->last_offset, SEEK_SET)) {
1489                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1490                 return false;
1491         }
1492         if(!copy_remaining_bytes_from_file_cb_(handle, read_cb, eof_cb, temp_handle, temp_write_cb, &status)) {
1493                 chain->status = get_equivalent_status_(status);
1494                 return false;
1495         }
1496
1497         return true;
1498 }
1499
1500 FLAC_API FLAC__Metadata_Chain *FLAC__metadata_chain_new(void)
1501 {
1502         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)calloc(1, sizeof(FLAC__Metadata_Chain));
1503
1504         if(0 != chain)
1505                 chain_init_(chain);
1506
1507         return chain;
1508 }
1509
1510 FLAC_API void FLAC__metadata_chain_delete(FLAC__Metadata_Chain *chain)
1511 {
1512         FLAC__ASSERT(0 != chain);
1513
1514         chain_clear_(chain);
1515
1516         free(chain);
1517 }
1518
1519 FLAC_API FLAC__Metadata_ChainStatus FLAC__metadata_chain_status(FLAC__Metadata_Chain *chain)
1520 {
1521         FLAC__Metadata_ChainStatus status;
1522
1523         FLAC__ASSERT(0 != chain);
1524
1525         status = chain->status;
1526         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
1527         return status;
1528 }
1529
1530 static FLAC__bool chain_read_(FLAC__Metadata_Chain *chain, const char *filename, FLAC__bool is_ogg)
1531 {
1532         FILE *file;
1533         FLAC__bool ret;
1534
1535         FLAC__ASSERT(0 != chain);
1536         FLAC__ASSERT(0 != filename);
1537
1538         chain_clear_(chain);
1539
1540         if(0 == (chain->filename = strdup(filename))) {
1541                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1542                 return false;
1543         }
1544
1545         chain->is_ogg = is_ogg;
1546
1547         if(0 == (file = fopen(filename, "rb"))) {
1548                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1549                 return false;
1550         }
1551
1552         /* the function also sets chain->status for us */
1553         ret = is_ogg?
1554                 chain_read_ogg_cb_(chain, file, (FLAC__IOCallback_Read)fread) :
1555                 chain_read_cb_(chain, file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, ftell_wrapper_)
1556         ;
1557
1558         fclose(file);
1559
1560         return ret;
1561 }
1562
1563 FLAC_API FLAC__bool FLAC__metadata_chain_read(FLAC__Metadata_Chain *chain, const char *filename)
1564 {
1565         return chain_read_(chain, filename, /*is_ogg=*/false);
1566 }
1567
1568 /*@@@@add to tests*/
1569 FLAC_API FLAC__bool FLAC__metadata_chain_read_ogg(FLAC__Metadata_Chain *chain, const char *filename)
1570 {
1571         return chain_read_(chain, filename, /*is_ogg=*/true);
1572 }
1573
1574 static FLAC__bool chain_read_with_callbacks_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks, FLAC__bool is_ogg)
1575 {
1576         FLAC__bool ret;
1577
1578         FLAC__ASSERT(0 != chain);
1579
1580         chain_clear_(chain);
1581
1582         if (0 == callbacks.read || 0 == callbacks.seek || 0 == callbacks.tell) {
1583                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1584                 return false;
1585         }
1586
1587         chain->is_ogg = is_ogg;
1588
1589         /* rewind */
1590         if(0 != callbacks.seek(handle, 0, SEEK_SET)) {
1591                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1592                 return false;
1593         }
1594
1595         /* the function also sets chain->status for us */
1596         ret = is_ogg?
1597                 chain_read_ogg_cb_(chain, handle, callbacks.read) :
1598                 chain_read_cb_(chain, handle, callbacks.read, callbacks.seek, callbacks.tell)
1599         ;
1600
1601         return ret;
1602 }
1603
1604 FLAC_API FLAC__bool FLAC__metadata_chain_read_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1605 {
1606         return chain_read_with_callbacks_(chain, handle, callbacks, /*is_ogg=*/false);
1607 }
1608
1609 /*@@@@add to tests*/
1610 FLAC_API FLAC__bool FLAC__metadata_chain_read_ogg_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1611 {
1612         return chain_read_with_callbacks_(chain, handle, callbacks, /*is_ogg=*/true);
1613 }
1614
1615 FLAC_API FLAC__bool FLAC__metadata_chain_check_if_tempfile_needed(FLAC__Metadata_Chain *chain, FLAC__bool use_padding)
1616 {
1617         /* This does all the same checks that are in chain_prepare_for_write_()
1618          * but doesn't actually alter the chain.  Make sure to update the logic
1619          * here if chain_prepare_for_write_() changes.
1620          */
1621         const off_t current_length = chain_calculate_length_(chain);
1622
1623         FLAC__ASSERT(0 != chain);
1624
1625         if(use_padding) {
1626                 /* if the metadata shrank and the last block is padding, we just extend the last padding block */
1627                 if(current_length < chain->initial_length && chain->tail->data->type == FLAC__METADATA_TYPE_PADDING)
1628                         return false;
1629                 /* if the metadata shrank more than 4 bytes then there's room to add another padding block */
1630                 else if(current_length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH <= chain->initial_length)
1631                         return false;
1632                 /* 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 */
1633                 else if(current_length > chain->initial_length) {
1634                         const off_t delta = current_length - chain->initial_length;
1635                         if(chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1636                                 /* if the delta is exactly the size of the last padding block, remove the padding block */
1637                                 if((off_t)chain->tail->data->length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH == delta)
1638                                         return false;
1639                                 /* if there is at least 'delta' bytes of padding, trim the padding down */
1640                                 else if((off_t)chain->tail->data->length >= delta)
1641                                         return false;
1642                         }
1643                 }
1644         }
1645
1646         return (current_length != chain->initial_length);
1647 }
1648
1649 FLAC_API FLAC__bool FLAC__metadata_chain_write(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__bool preserve_file_stats)
1650 {
1651         struct stat stats;
1652         const char *tempfile_path_prefix = 0;
1653         off_t current_length;
1654
1655         FLAC__ASSERT(0 != chain);
1656
1657         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1658                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1659                 return false;
1660         }
1661
1662         if (0 == chain->filename) {
1663                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1664                 return false;
1665         }
1666
1667         current_length = chain_prepare_for_write_(chain, use_padding);
1668
1669         /* a return value of 0 means there was an error; chain->status is already set */
1670         if (0 == current_length)
1671                 return false;
1672
1673         if(preserve_file_stats)
1674                 get_file_stats_(chain->filename, &stats);
1675
1676         if(current_length == chain->initial_length) {
1677                 if(!chain_rewrite_metadata_in_place_(chain))
1678                         return false;
1679         }
1680         else {
1681                 if(!chain_rewrite_file_(chain, tempfile_path_prefix))
1682                         return false;
1683
1684                 /* recompute lengths and offsets */
1685                 {
1686                         const FLAC__Metadata_Node *node;
1687                         chain->initial_length = current_length;
1688                         chain->last_offset = chain->first_offset;
1689                         for(node = chain->head; node; node = node->next)
1690                                 chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1691                 }
1692         }
1693
1694         if(preserve_file_stats)
1695                 set_file_stats_(chain->filename, &stats);
1696
1697         return true;
1698 }
1699
1700 FLAC_API FLAC__bool FLAC__metadata_chain_write_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1701 {
1702         off_t current_length;
1703
1704         FLAC__ASSERT(0 != chain);
1705
1706         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1707                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1708                 return false;
1709         }
1710
1711         if (0 != chain->filename) {
1712                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1713                 return false;
1714         }
1715
1716         if (0 == callbacks.write || 0 == callbacks.seek) {
1717                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1718                 return false;
1719         }
1720
1721         if (FLAC__metadata_chain_check_if_tempfile_needed(chain, use_padding)) {
1722                 chain->status = FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL;
1723                 return false;
1724         }
1725
1726         current_length = chain_prepare_for_write_(chain, use_padding);
1727
1728         /* a return value of 0 means there was an error; chain->status is already set */
1729         if (0 == current_length)
1730                 return false;
1731
1732         FLAC__ASSERT(current_length == chain->initial_length);
1733
1734         return chain_rewrite_metadata_in_place_cb_(chain, handle, callbacks.write, callbacks.seek);
1735 }
1736
1737 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)
1738 {
1739         off_t current_length;
1740
1741         FLAC__ASSERT(0 != chain);
1742
1743         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1744                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1745                 return false;
1746         }
1747
1748         if (0 != chain->filename) {
1749                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1750                 return false;
1751         }
1752
1753         if (0 == callbacks.read || 0 == callbacks.seek || 0 == callbacks.eof) {
1754                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1755                 return false;
1756         }
1757         if (0 == temp_callbacks.write) {
1758                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1759                 return false;
1760         }
1761
1762         if (!FLAC__metadata_chain_check_if_tempfile_needed(chain, use_padding)) {
1763                 chain->status = FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL;
1764                 return false;
1765         }
1766
1767         current_length = chain_prepare_for_write_(chain, use_padding);
1768
1769         /* a return value of 0 means there was an error; chain->status is already set */
1770         if (0 == current_length)
1771                 return false;
1772
1773         FLAC__ASSERT(current_length != chain->initial_length);
1774
1775         /* rewind */
1776         if(0 != callbacks.seek(handle, 0, SEEK_SET)) {
1777                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1778                 return false;
1779         }
1780
1781         if(!chain_rewrite_file_cb_(chain, handle, callbacks.read, callbacks.seek, callbacks.eof, temp_handle, temp_callbacks.write))
1782                 return false;
1783
1784         /* recompute lengths and offsets */
1785         {
1786                 const FLAC__Metadata_Node *node;
1787                 chain->initial_length = current_length;
1788                 chain->last_offset = chain->first_offset;
1789                 for(node = chain->head; node; node = node->next)
1790                         chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1791         }
1792
1793         return true;
1794 }
1795
1796 FLAC_API void FLAC__metadata_chain_merge_padding(FLAC__Metadata_Chain *chain)
1797 {
1798         FLAC__Metadata_Node *node;
1799
1800         FLAC__ASSERT(0 != chain);
1801
1802         for(node = chain->head; node; ) {
1803                 if(!chain_merge_adjacent_padding_(chain, node))
1804                         node = node->next;
1805         }
1806 }
1807
1808 FLAC_API void FLAC__metadata_chain_sort_padding(FLAC__Metadata_Chain *chain)
1809 {
1810         FLAC__Metadata_Node *node, *save;
1811         unsigned i;
1812
1813         FLAC__ASSERT(0 != chain);
1814
1815         /*
1816          * Don't try and be too smart... this simple algo is good enough for
1817          * the small number of nodes that we deal with.
1818          */
1819         for(i = 0, node = chain->head; i < chain->nodes; i++) {
1820                 if(node->data->type == FLAC__METADATA_TYPE_PADDING) {
1821                         save = node->next;
1822                         chain_remove_node_(chain, node);
1823                         chain_append_node_(chain, node);
1824                         node = save;
1825                 }
1826                 else {
1827                         node = node->next;
1828                 }
1829         }
1830
1831         FLAC__metadata_chain_merge_padding(chain);
1832 }
1833
1834
1835 FLAC_API FLAC__Metadata_Iterator *FLAC__metadata_iterator_new(void)
1836 {
1837         FLAC__Metadata_Iterator *iterator = (FLAC__Metadata_Iterator*)calloc(1, sizeof(FLAC__Metadata_Iterator));
1838
1839         /* calloc() implies:
1840                 iterator->current = 0;
1841                 iterator->chain = 0;
1842         */
1843
1844         return iterator;
1845 }
1846
1847 FLAC_API void FLAC__metadata_iterator_delete(FLAC__Metadata_Iterator *iterator)
1848 {
1849         FLAC__ASSERT(0 != iterator);
1850
1851         free(iterator);
1852 }
1853
1854 FLAC_API void FLAC__metadata_iterator_init(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Chain *chain)
1855 {
1856         FLAC__ASSERT(0 != iterator);
1857         FLAC__ASSERT(0 != chain);
1858         FLAC__ASSERT(0 != chain->head);
1859
1860         iterator->chain = chain;
1861         iterator->current = chain->head;
1862 }
1863
1864 FLAC_API FLAC__bool FLAC__metadata_iterator_next(FLAC__Metadata_Iterator *iterator)
1865 {
1866         FLAC__ASSERT(0 != iterator);
1867
1868         if(0 == iterator->current || 0 == iterator->current->next)
1869                 return false;
1870
1871         iterator->current = iterator->current->next;
1872         return true;
1873 }
1874
1875 FLAC_API FLAC__bool FLAC__metadata_iterator_prev(FLAC__Metadata_Iterator *iterator)
1876 {
1877         FLAC__ASSERT(0 != iterator);
1878
1879         if(0 == iterator->current || 0 == iterator->current->prev)
1880                 return false;
1881
1882         iterator->current = iterator->current->prev;
1883         return true;
1884 }
1885
1886 FLAC_API FLAC__MetadataType FLAC__metadata_iterator_get_block_type(const FLAC__Metadata_Iterator *iterator)
1887 {
1888         FLAC__ASSERT(0 != iterator);
1889         FLAC__ASSERT(0 != iterator->current);
1890         FLAC__ASSERT(0 != iterator->current->data);
1891
1892         return iterator->current->data->type;
1893 }
1894
1895 FLAC_API FLAC__StreamMetadata *FLAC__metadata_iterator_get_block(FLAC__Metadata_Iterator *iterator)
1896 {
1897         FLAC__ASSERT(0 != iterator);
1898         FLAC__ASSERT(0 != iterator->current);
1899
1900         return iterator->current->data;
1901 }
1902
1903 FLAC_API FLAC__bool FLAC__metadata_iterator_set_block(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1904 {
1905         FLAC__ASSERT(0 != iterator);
1906         FLAC__ASSERT(0 != block);
1907         return FLAC__metadata_iterator_delete_block(iterator, false) && FLAC__metadata_iterator_insert_block_after(iterator, block);
1908 }
1909
1910 FLAC_API FLAC__bool FLAC__metadata_iterator_delete_block(FLAC__Metadata_Iterator *iterator, FLAC__bool replace_with_padding)
1911 {
1912         FLAC__Metadata_Node *save;
1913
1914         FLAC__ASSERT(0 != iterator);
1915         FLAC__ASSERT(0 != iterator->current);
1916
1917         if(0 == iterator->current->prev) {
1918                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1919                 return false;
1920         }
1921
1922         save = iterator->current->prev;
1923
1924         if(replace_with_padding) {
1925                 FLAC__metadata_object_delete_data(iterator->current->data);
1926                 iterator->current->data->type = FLAC__METADATA_TYPE_PADDING;
1927         }
1928         else {
1929                 chain_delete_node_(iterator->chain, iterator->current);
1930         }
1931
1932         iterator->current = save;
1933         return true;
1934 }
1935
1936 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_before(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1937 {
1938         FLAC__Metadata_Node *node;
1939
1940         FLAC__ASSERT(0 != iterator);
1941         FLAC__ASSERT(0 != iterator->current);
1942         FLAC__ASSERT(0 != block);
1943
1944         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1945                 return false;
1946
1947         if(0 == iterator->current->prev) {
1948                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1949                 return false;
1950         }
1951
1952         if(0 == (node = node_new_()))
1953                 return false;
1954
1955         node->data = block;
1956         iterator_insert_node_(iterator, node);
1957         iterator->current = node;
1958         return true;
1959 }
1960
1961 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_after(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1962 {
1963         FLAC__Metadata_Node *node;
1964
1965         FLAC__ASSERT(0 != iterator);
1966         FLAC__ASSERT(0 != iterator->current);
1967         FLAC__ASSERT(0 != block);
1968
1969         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1970                 return false;
1971
1972         if(0 == (node = node_new_()))
1973                 return false;
1974
1975         node->data = block;
1976         iterator_insert_node_after_(iterator, node);
1977         iterator->current = node;
1978         return true;
1979 }
1980
1981
1982 /****************************************************************************
1983  *
1984  * Local function definitions
1985  *
1986  ***************************************************************************/
1987
1988 void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
1989 {
1990         unsigned i;
1991
1992         b += bytes;
1993
1994         for(i = 0; i < bytes; i++) {
1995                 *(--b) = (FLAC__byte)(val & 0xff);
1996                 val >>= 8;
1997         }
1998 }
1999
2000 void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
2001 {
2002         unsigned i;
2003
2004         for(i = 0; i < bytes; i++) {
2005                 *(b++) = (FLAC__byte)(val & 0xff);
2006                 val >>= 8;
2007         }
2008 }
2009
2010 void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes)
2011 {
2012         unsigned i;
2013
2014         b += bytes;
2015
2016         for(i = 0; i < bytes; i++) {
2017                 *(--b) = (FLAC__byte)(val & 0xff);
2018                 val >>= 8;
2019         }
2020 }
2021
2022 FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes)
2023 {
2024         FLAC__uint32 ret = 0;
2025         unsigned i;
2026
2027         for(i = 0; i < bytes; i++)
2028                 ret = (ret << 8) | (FLAC__uint32)(*b++);
2029
2030         return ret;
2031 }
2032
2033 FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes)
2034 {
2035         FLAC__uint32 ret = 0;
2036         unsigned i;
2037
2038         b += bytes;
2039
2040         for(i = 0; i < bytes; i++)
2041                 ret = (ret << 8) | (FLAC__uint32)(*--b);
2042
2043         return ret;
2044 }
2045
2046 FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes)
2047 {
2048         FLAC__uint64 ret = 0;
2049         unsigned i;
2050
2051         for(i = 0; i < bytes; i++)
2052                 ret = (ret << 8) | (FLAC__uint64)(*b++);
2053
2054         return ret;
2055 }
2056
2057 FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator)
2058 {
2059         FLAC__ASSERT(0 != iterator);
2060         FLAC__ASSERT(0 != iterator->file);
2061
2062         if(!read_metadata_block_header_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, &iterator->is_last, &iterator->type, &iterator->length)) {
2063                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2064                 return false;
2065         }
2066
2067         return true;
2068 }
2069
2070 FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block)
2071 {
2072         FLAC__ASSERT(0 != iterator);
2073         FLAC__ASSERT(0 != iterator->file);
2074
2075         iterator->status = read_metadata_block_data_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, block);
2076
2077         return (iterator->status == FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK);
2078 }
2079
2080 FLAC__bool read_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__bool *is_last, FLAC__MetadataType *type, unsigned *length)
2081 {
2082         FLAC__byte raw_header[FLAC__STREAM_METADATA_HEADER_LENGTH];
2083
2084         if(read_cb(raw_header, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
2085                 return false;
2086
2087         *is_last = raw_header[0] & 0x80? true : false;
2088         *type = (FLAC__MetadataType)(raw_header[0] & 0x7f);
2089         *length = unpack_uint32_(raw_header + 1, 3);
2090
2091         /* Note that we don't check:
2092          *    if(iterator->type >= FLAC__METADATA_TYPE_UNDEFINED)
2093          * we just will read in an opaque block
2094          */
2095
2096         return true;
2097 }
2098
2099 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata *block)
2100 {
2101         switch(block->type) {
2102                 case FLAC__METADATA_TYPE_STREAMINFO:
2103                         return read_metadata_block_data_streaminfo_cb_(handle, read_cb, &block->data.stream_info);
2104                 case FLAC__METADATA_TYPE_PADDING:
2105                         return read_metadata_block_data_padding_cb_(handle, seek_cb, &block->data.padding, block->length);
2106                 case FLAC__METADATA_TYPE_APPLICATION:
2107                         return read_metadata_block_data_application_cb_(handle, read_cb, &block->data.application, block->length);
2108                 case FLAC__METADATA_TYPE_SEEKTABLE:
2109                         return read_metadata_block_data_seektable_cb_(handle, read_cb, &block->data.seek_table, block->length);
2110                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
2111                         return read_metadata_block_data_vorbis_comment_cb_(handle, read_cb, &block->data.vorbis_comment);
2112                 case FLAC__METADATA_TYPE_CUESHEET:
2113                         return read_metadata_block_data_cuesheet_cb_(handle, read_cb, &block->data.cue_sheet);
2114                 case FLAC__METADATA_TYPE_PICTURE:
2115                         return read_metadata_block_data_picture_cb_(handle, read_cb, &block->data.picture);
2116                 default:
2117                         return read_metadata_block_data_unknown_cb_(handle, read_cb, &block->data.unknown, block->length);
2118         }
2119 }
2120
2121 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_StreamInfo *block)
2122 {
2123         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH], *b;
2124
2125         if(read_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
2126                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2127
2128         b = buffer;
2129
2130         /* we are using hardcoded numbers for simplicity but we should
2131          * probably eventually write a bit-level unpacker and use the
2132          * _STREAMINFO_ constants.
2133          */
2134         block->min_blocksize = unpack_uint32_(b, 2); b += 2;
2135         block->max_blocksize = unpack_uint32_(b, 2); b += 2;
2136         block->min_framesize = unpack_uint32_(b, 3); b += 3;
2137         block->max_framesize = unpack_uint32_(b, 3); b += 3;
2138         block->sample_rate = (unpack_uint32_(b, 2) << 4) | ((unsigned)(b[2] & 0xf0) >> 4);
2139         block->channels = (unsigned)((b[2] & 0x0e) >> 1) + 1;
2140         block->bits_per_sample = ((((unsigned)(b[2] & 0x01)) << 4) | (((unsigned)(b[3] & 0xf0)) >> 4)) + 1;
2141         block->total_samples = (((FLAC__uint64)(b[3] & 0x0f)) << 32) | unpack_uint64_(b+4, 4);
2142         memcpy(block->md5sum, b+8, 16);
2143
2144         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2145 }
2146
2147 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata_Padding *block, unsigned block_length)
2148 {
2149         (void)block; /* nothing to do; we don't care about reading the padding bytes */
2150
2151         if(0 != seek_cb(handle, block_length, SEEK_CUR))
2152                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2153
2154         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2155 }
2156
2157 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Application *block, unsigned block_length)
2158 {
2159         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
2160
2161         if(read_cb(block->id, 1, id_bytes, handle) != id_bytes)
2162                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2163
2164         if(block_length < id_bytes)
2165                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2166
2167         block_length -= id_bytes;
2168
2169         if(block_length == 0) {
2170                 block->data = 0;
2171         }
2172         else {
2173                 if(0 == (block->data = (FLAC__byte*)malloc(block_length)))
2174                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2175
2176                 if(read_cb(block->data, 1, block_length, handle) != block_length)
2177                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2178         }
2179
2180         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2181 }
2182
2183 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_SeekTable *block, unsigned block_length)
2184 {
2185         unsigned i;
2186         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
2187
2188         FLAC__ASSERT(block_length % FLAC__STREAM_METADATA_SEEKPOINT_LENGTH == 0);
2189
2190         block->num_points = block_length / FLAC__STREAM_METADATA_SEEKPOINT_LENGTH;
2191
2192         if(block->num_points == 0)
2193                 block->points = 0;
2194         else if(0 == (block->points = (FLAC__StreamMetadata_SeekPoint*)safe_malloc_mul_2op_(block->num_points, /*times*/sizeof(FLAC__StreamMetadata_SeekPoint))))
2195                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2196
2197         for(i = 0; i < block->num_points; i++) {
2198                 if(read_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
2199                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2200                 /* some MAGIC NUMBERs here */
2201                 block->points[i].sample_number = unpack_uint64_(buffer, 8);
2202                 block->points[i].stream_offset = unpack_uint64_(buffer+8, 8);
2203                 block->points[i].frame_samples = unpack_uint32_(buffer+16, 2);
2204         }
2205
2206         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2207 }
2208
2209 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_entry_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment_Entry *entry)
2210 {
2211         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
2212         FLAC__byte buffer[4]; /* magic number is asserted below */
2213
2214         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8 == sizeof(buffer));
2215
2216         if(read_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2217                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2218         entry->length = unpack_uint32_little_endian_(buffer, entry_length_len);
2219
2220         if(0 != entry->entry)
2221                 free(entry->entry);
2222
2223         if(entry->length == 0) {
2224                 entry->entry = 0;
2225         }
2226         else {
2227                 if(0 == (entry->entry = (FLAC__byte*)safe_malloc_add_2op_(entry->length, /*+*/1)))
2228                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2229
2230                 if(read_cb(entry->entry, 1, entry->length, handle) != entry->length)
2231                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2232
2233                 entry->entry[entry->length] = '\0';
2234         }
2235
2236         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2237 }
2238
2239 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment *block)
2240 {
2241         unsigned i;
2242         FLAC__Metadata_SimpleIteratorStatus status;
2243         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2244         FLAC__byte buffer[4]; /* magic number is asserted below */
2245
2246         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8 == sizeof(buffer));
2247
2248         if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, &(block->vendor_string))))
2249                 return status;
2250
2251         if(read_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2252                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2253         block->num_comments = unpack_uint32_little_endian_(buffer, num_comments_len);
2254
2255         if(block->num_comments == 0) {
2256                 block->comments = 0;
2257         }
2258         else if(0 == (block->comments = (FLAC__StreamMetadata_VorbisComment_Entry*)calloc(block->num_comments, sizeof(FLAC__StreamMetadata_VorbisComment_Entry))))
2259                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2260
2261         for(i = 0; i < block->num_comments; i++) {
2262                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, block->comments + i)))
2263                         return status;
2264         }
2265
2266         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2267 }
2268
2269 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet_Track *track)
2270 {
2271         unsigned i, len;
2272         FLAC__byte buffer[32]; /* asserted below that this is big enough */
2273
2274         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2275         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2276         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);
2277
2278         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2279         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2280         if(read_cb(buffer, 1, len, handle) != len)
2281                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2282         track->offset = unpack_uint64_(buffer, len);
2283
2284         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2285         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2286         if(read_cb(buffer, 1, len, handle) != len)
2287                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2288         track->number = (FLAC__byte)unpack_uint32_(buffer, len);
2289
2290         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2291         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2292         if(read_cb(track->isrc, 1, len, handle) != len)
2293                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2294
2295         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);
2296         len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2297         if(read_cb(buffer, 1, len, handle) != len)
2298                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2299         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN == 1);
2300         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN == 1);
2301         track->type = buffer[0] >> 7;
2302         track->pre_emphasis = (buffer[0] >> 6) & 1;
2303
2304         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2305         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2306         if(read_cb(buffer, 1, len, handle) != len)
2307                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2308         track->num_indices = (FLAC__byte)unpack_uint32_(buffer, len);
2309
2310         if(track->num_indices == 0) {
2311                 track->indices = 0;
2312         }
2313         else if(0 == (track->indices = (FLAC__StreamMetadata_CueSheet_Index*)calloc(track->num_indices, sizeof(FLAC__StreamMetadata_CueSheet_Index))))
2314                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2315
2316         for(i = 0; i < track->num_indices; i++) {
2317                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2318                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2319                 if(read_cb(buffer, 1, len, handle) != len)
2320                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2321                 track->indices[i].offset = unpack_uint64_(buffer, len);
2322
2323                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2324                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2325                 if(read_cb(buffer, 1, len, handle) != len)
2326                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2327                 track->indices[i].number = (FLAC__byte)unpack_uint32_(buffer, len);
2328
2329                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2330                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2331                 if(read_cb(buffer, 1, len, handle) != len)
2332                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2333         }
2334
2335         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2336 }
2337
2338 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet *block)
2339 {
2340         unsigned i, len;
2341         FLAC__Metadata_SimpleIteratorStatus status;
2342         FLAC__byte buffer[1024]; /* MSVC needs a constant expression so we put a magic number and assert */
2343
2344         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN)/8 <= sizeof(buffer));
2345         FLAC__ASSERT(sizeof(FLAC__uint64) <= sizeof(buffer));
2346
2347         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2348         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2349         if(read_cb(block->media_catalog_number, 1, len, handle) != len)
2350                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2351
2352         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2353         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2354         if(read_cb(buffer, 1, len, handle) != len)
2355                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2356         block->lead_in = unpack_uint64_(buffer, len);
2357
2358         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2359         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2360         if(read_cb(buffer, 1, len, handle) != len)
2361                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2362         block->is_cd = buffer[0]&0x80? true : false;
2363
2364         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2365         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2366         if(read_cb(buffer, 1, len, handle) != len)
2367                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2368         block->num_tracks = unpack_uint32_(buffer, len);
2369
2370         if(block->num_tracks == 0) {
2371                 block->tracks = 0;
2372         }
2373         else if(0 == (block->tracks = (FLAC__StreamMetadata_CueSheet_Track*)calloc(block->num_tracks, sizeof(FLAC__StreamMetadata_CueSheet_Track))))
2374                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2375
2376         for(i = 0; i < block->num_tracks; i++) {
2377                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_cuesheet_track_cb_(handle, read_cb, block->tracks + i)))
2378                         return status;
2379         }
2380
2381         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2382 }
2383
2384 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)
2385 {
2386         FLAC__byte buffer[sizeof(FLAC__uint32)];
2387
2388         FLAC__ASSERT(0 != data);
2389         FLAC__ASSERT(length_len%8 == 0);
2390
2391         length_len /= 8; /* convert to bytes */
2392
2393         FLAC__ASSERT(sizeof(buffer) >= length_len);
2394
2395         if(read_cb(buffer, 1, length_len, handle) != length_len)
2396                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2397         *length = unpack_uint32_(buffer, length_len);
2398
2399         if(0 != *data)
2400                 free(*data);
2401
2402         if(0 == (*data = (FLAC__byte*)safe_malloc_add_2op_(*length, /*+*/1)))
2403                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2404
2405         if(*length > 0) {
2406                 if(read_cb(*data, 1, *length, handle) != *length)
2407                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2408         }
2409
2410         (*data)[*length] = '\0';
2411
2412         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2413 }
2414
2415 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Picture *block)
2416 {
2417         FLAC__Metadata_SimpleIteratorStatus status;
2418         FLAC__byte buffer[4]; /* asserted below that this is big enough */
2419         FLAC__uint32 len;
2420
2421         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8);
2422         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8);
2423         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8);
2424         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8);
2425         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8);
2426
2427         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_TYPE_LEN % 8 == 0);
2428         len = FLAC__STREAM_METADATA_PICTURE_TYPE_LEN / 8;
2429         if(read_cb(buffer, 1, len, handle) != len)
2430                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2431         block->type = (FLAC__StreamMetadata_Picture_Type)unpack_uint32_(buffer, len);
2432
2433         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)
2434                 return status;
2435
2436         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)
2437                 return status;
2438
2439         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN % 8 == 0);
2440         len = FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN / 8;
2441         if(read_cb(buffer, 1, len, handle) != len)
2442                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2443         block->width = unpack_uint32_(buffer, len);
2444
2445         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN % 8 == 0);
2446         len = FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN / 8;
2447         if(read_cb(buffer, 1, len, handle) != len)
2448                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2449         block->height = unpack_uint32_(buffer, len);
2450
2451         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN % 8 == 0);
2452         len = FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN / 8;
2453         if(read_cb(buffer, 1, len, handle) != len)
2454                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2455         block->depth = unpack_uint32_(buffer, len);
2456
2457         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_COLORS_LEN % 8 == 0);
2458         len = FLAC__STREAM_METADATA_PICTURE_COLORS_LEN / 8;
2459         if(read_cb(buffer, 1, len, handle) != len)
2460                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2461         block->colors = unpack_uint32_(buffer, len);
2462
2463         /* for convenience we use read_metadata_block_data_picture_cstring_cb_() even though it adds an extra terminating NUL we don't use */
2464         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)
2465                 return status;
2466
2467         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2468 }
2469
2470 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2471 {
2472         if(block_length == 0) {
2473                 block->data = 0;
2474         }
2475         else {
2476                 if(0 == (block->data = (FLAC__byte*)malloc(block_length)))
2477                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2478
2479                 if(read_cb(block->data, 1, block_length, handle) != block_length)
2480                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2481         }
2482
2483         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2484 }
2485
2486 FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2487 {
2488         FLAC__ASSERT(0 != file);
2489         FLAC__ASSERT(0 != status);
2490
2491         if(!write_metadata_block_header_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2492                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2493                 return false;
2494         }
2495
2496         return true;
2497 }
2498
2499 FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2500 {
2501         FLAC__ASSERT(0 != file);
2502         FLAC__ASSERT(0 != status);
2503
2504         if (write_metadata_block_data_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2505                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2506                 return true;
2507         }
2508         else {
2509                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2510                 return false;
2511         }
2512 }
2513
2514 FLAC__bool write_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2515 {
2516         FLAC__byte buffer[FLAC__STREAM_METADATA_HEADER_LENGTH];
2517
2518         FLAC__ASSERT(block->length < (1u << FLAC__STREAM_METADATA_LENGTH_LEN));
2519
2520         buffer[0] = (block->is_last? 0x80 : 0) | (FLAC__byte)block->type;
2521         pack_uint32_(block->length, buffer + 1, 3);
2522
2523         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
2524                 return false;
2525
2526         return true;
2527 }
2528
2529 FLAC__bool write_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2530 {
2531         FLAC__ASSERT(0 != block);
2532
2533         switch(block->type) {
2534                 case FLAC__METADATA_TYPE_STREAMINFO:
2535                         return write_metadata_block_data_streaminfo_cb_(handle, write_cb, &block->data.stream_info);
2536                 case FLAC__METADATA_TYPE_PADDING:
2537                         return write_metadata_block_data_padding_cb_(handle, write_cb, &block->data.padding, block->length);
2538                 case FLAC__METADATA_TYPE_APPLICATION:
2539                         return write_metadata_block_data_application_cb_(handle, write_cb, &block->data.application, block->length);
2540                 case FLAC__METADATA_TYPE_SEEKTABLE:
2541                         return write_metadata_block_data_seektable_cb_(handle, write_cb, &block->data.seek_table);
2542                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
2543                         return write_metadata_block_data_vorbis_comment_cb_(handle, write_cb, &block->data.vorbis_comment);
2544                 case FLAC__METADATA_TYPE_CUESHEET:
2545                         return write_metadata_block_data_cuesheet_cb_(handle, write_cb, &block->data.cue_sheet);
2546                 case FLAC__METADATA_TYPE_PICTURE:
2547                         return write_metadata_block_data_picture_cb_(handle, write_cb, &block->data.picture);
2548                 default:
2549                         return write_metadata_block_data_unknown_cb_(handle, write_cb, &block->data.unknown, block->length);
2550         }
2551 }
2552
2553 FLAC__bool write_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_StreamInfo *block)
2554 {
2555         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH];
2556         const unsigned channels1 = block->channels - 1;
2557         const unsigned bps1 = block->bits_per_sample - 1;
2558
2559         /* we are using hardcoded numbers for simplicity but we should
2560          * probably eventually write a bit-level packer and use the
2561          * _STREAMINFO_ constants.
2562          */
2563         pack_uint32_(block->min_blocksize, buffer, 2);
2564         pack_uint32_(block->max_blocksize, buffer+2, 2);
2565         pack_uint32_(block->min_framesize, buffer+4, 3);
2566         pack_uint32_(block->max_framesize, buffer+7, 3);
2567         buffer[10] = (block->sample_rate >> 12) & 0xff;
2568         buffer[11] = (block->sample_rate >> 4) & 0xff;
2569         buffer[12] = ((block->sample_rate & 0x0f) << 4) | (channels1 << 1) | (bps1 >> 4);
2570         buffer[13] = (FLAC__byte)(((bps1 & 0x0f) << 4) | ((block->total_samples >> 32) & 0x0f));
2571         pack_uint32_((FLAC__uint32)block->total_samples, buffer+14, 4);
2572         memcpy(buffer+18, block->md5sum, 16);
2573
2574         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
2575                 return false;
2576
2577         return true;
2578 }
2579
2580 FLAC__bool write_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Padding *block, unsigned block_length)
2581 {
2582         unsigned i, n = block_length;
2583         FLAC__byte buffer[1024];
2584
2585         (void)block;
2586
2587         memset(buffer, 0, 1024);
2588
2589         for(i = 0; i < n/1024; i++)
2590                 if(write_cb(buffer, 1, 1024, handle) != 1024)
2591                         return false;
2592
2593         n %= 1024;
2594
2595         if(write_cb(buffer, 1, n, handle) != n)
2596                 return false;
2597
2598         return true;
2599 }
2600
2601 FLAC__bool write_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Application *block, unsigned block_length)
2602 {
2603         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
2604
2605         if(write_cb(block->id, 1, id_bytes, handle) != id_bytes)
2606                 return false;
2607
2608         block_length -= id_bytes;
2609
2610         if(write_cb(block->data, 1, block_length, handle) != block_length)
2611                 return false;
2612
2613         return true;
2614 }
2615
2616 FLAC__bool write_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_SeekTable *block)
2617 {
2618         unsigned i;
2619         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
2620
2621         for(i = 0; i < block->num_points; i++) {
2622                 /* some MAGIC NUMBERs here */
2623                 pack_uint64_(block->points[i].sample_number, buffer, 8);
2624                 pack_uint64_(block->points[i].stream_offset, buffer+8, 8);
2625                 pack_uint32_(block->points[i].frame_samples, buffer+16, 2);
2626                 if(write_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
2627                         return false;
2628         }
2629
2630         return true;
2631 }
2632
2633 FLAC__bool write_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_VorbisComment *block)
2634 {
2635         unsigned i;
2636         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
2637         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2638         FLAC__byte buffer[4]; /* magic number is asserted below */
2639
2640         FLAC__ASSERT(max(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN, FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN) / 8 == sizeof(buffer));
2641
2642         pack_uint32_little_endian_(block->vendor_string.length, buffer, entry_length_len);
2643         if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2644                 return false;
2645         if(write_cb(block->vendor_string.entry, 1, block->vendor_string.length, handle) != block->vendor_string.length)
2646                 return false;
2647
2648         pack_uint32_little_endian_(block->num_comments, buffer, num_comments_len);
2649         if(write_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2650                 return false;
2651
2652         for(i = 0; i < block->num_comments; i++) {
2653                 pack_uint32_little_endian_(block->comments[i].length, buffer, entry_length_len);
2654                 if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2655                         return false;
2656                 if(write_cb(block->comments[i].entry, 1, block->comments[i].length, handle) != block->comments[i].length)
2657                         return false;
2658         }
2659
2660         return true;
2661 }
2662
2663 FLAC__bool write_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_CueSheet *block)
2664 {
2665         unsigned i, j, len;
2666         FLAC__byte buffer[1024]; /* asserted below that this is big enough */
2667
2668         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2669         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN/8);
2670         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);
2671         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2672
2673         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2674         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2675         if(write_cb(block->media_catalog_number, 1, len, handle) != len)
2676                 return false;
2677
2678         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2679         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2680         pack_uint64_(block->lead_in, buffer, len);
2681         if(write_cb(buffer, 1, len, handle) != len)
2682                 return false;
2683
2684         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2685         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2686         memset(buffer, 0, len);
2687         if(block->is_cd)
2688                 buffer[0] |= 0x80;
2689         if(write_cb(buffer, 1, len, handle) != len)
2690                 return false;
2691
2692         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2693         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2694         pack_uint32_(block->num_tracks, buffer, len);
2695         if(write_cb(buffer, 1, len, handle) != len)
2696                 return false;
2697
2698         for(i = 0; i < block->num_tracks; i++) {
2699                 FLAC__StreamMetadata_CueSheet_Track *track = block->tracks + i;
2700
2701                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2702                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2703                 pack_uint64_(track->offset, buffer, len);
2704                 if(write_cb(buffer, 1, len, handle) != len)
2705                         return false;
2706
2707                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2708                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2709                 pack_uint32_(track->number, buffer, len);
2710                 if(write_cb(buffer, 1, len, handle) != len)
2711                         return false;
2712
2713                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2714                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2715                 if(write_cb(track->isrc, 1, len, handle) != len)
2716                         return false;
2717
2718                 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);
2719                 len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2720                 memset(buffer, 0, len);
2721                 buffer[0] = (track->type << 7) | (track->pre_emphasis << 6);
2722                 if(write_cb(buffer, 1, len, handle) != len)
2723                         return false;
2724
2725                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2726                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2727                 pack_uint32_(track->num_indices, buffer, len);
2728                 if(write_cb(buffer, 1, len, handle) != len)
2729                         return false;
2730
2731                 for(j = 0; j < track->num_indices; j++) {
2732                         FLAC__StreamMetadata_CueSheet_Index *index = track->indices + j;
2733
2734                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2735                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2736                         pack_uint64_(index->offset, buffer, len);
2737                         if(write_cb(buffer, 1, len, handle) != len)
2738                                 return false;
2739
2740                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2741                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2742                         pack_uint32_(index->number, buffer, len);
2743                         if(write_cb(buffer, 1, len, handle) != len)
2744                                 return false;
2745
2746                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2747                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2748                         memset(buffer, 0, len);
2749                         if(write_cb(buffer, 1, len, handle) != len)
2750                                 return false;
2751                 }
2752         }
2753
2754         return true;
2755 }
2756
2757 FLAC__bool write_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Picture *block)
2758 {
2759         unsigned len;
2760         size_t slen;
2761         FLAC__byte buffer[4]; /* magic number is asserted below */
2762
2763         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_TYPE_LEN%8);
2764         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN%8);
2765         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN%8);
2766         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN%8);
2767         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN%8);
2768         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN%8);
2769         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_COLORS_LEN%8);
2770         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN%8);
2771         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8);
2772         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN/8);
2773         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN/8);
2774         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8);
2775         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8);
2776         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8);
2777         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8);
2778         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN/8);
2779
2780         len = FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8;
2781         pack_uint32_(block->type, buffer, len);
2782         if(write_cb(buffer, 1, len, handle) != len)
2783                 return false;
2784
2785         len = FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN/8;
2786         slen = strlen(block->mime_type);
2787         pack_uint32_(slen, buffer, len);
2788         if(write_cb(buffer, 1, len, handle) != len)
2789                 return false;
2790         if(write_cb(block->mime_type, 1, slen, handle) != slen)
2791                 return false;
2792
2793         len = FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN/8;
2794         slen = strlen((const char *)block->description);
2795         pack_uint32_(slen, buffer, len);
2796         if(write_cb(buffer, 1, len, handle) != len)
2797                 return false;
2798         if(write_cb(block->description, 1, slen, handle) != slen)
2799                 return false;
2800
2801         len = FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8;
2802         pack_uint32_(block->width, buffer, len);
2803         if(write_cb(buffer, 1, len, handle) != len)
2804                 return false;
2805
2806         len = FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8;
2807         pack_uint32_(block->height, buffer, len);
2808         if(write_cb(buffer, 1, len, handle) != len)
2809                 return false;
2810
2811         len = FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8;
2812         pack_uint32_(block->depth, buffer, len);
2813         if(write_cb(buffer, 1, len, handle) != len)
2814                 return false;
2815
2816         len = FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8;
2817         pack_uint32_(block->colors, buffer, len);
2818         if(write_cb(buffer, 1, len, handle) != len)
2819                 return false;
2820
2821         len = FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN/8;
2822         pack_uint32_(block->data_length, buffer, len);
2823         if(write_cb(buffer, 1, len, handle) != len)
2824                 return false;
2825         if(write_cb(block->data, 1, block->data_length, handle) != block->data_length)
2826                 return false;
2827
2828         return true;
2829 }
2830
2831 FLAC__bool write_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2832 {
2833         if(write_cb(block->data, 1, block_length, handle) != block_length)
2834                 return false;
2835
2836         return true;
2837 }
2838
2839 FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block)
2840 {
2841         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2842                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2843                 return false;
2844         }
2845
2846         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2847                 return false;
2848
2849         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2850                 return false;
2851
2852         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2853                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2854                 return false;
2855         }
2856
2857         return read_metadata_block_header_(iterator);
2858 }
2859
2860 FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last)
2861 {
2862         FLAC__StreamMetadata *padding;
2863
2864         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2865                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2866                 return false;
2867         }
2868
2869         block->is_last = false;
2870
2871         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2872                 return false;
2873
2874         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2875                 return false;
2876
2877         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING)))
2878                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2879
2880         padding->is_last = padding_is_last;
2881         padding->length = padding_length;
2882
2883         if(!write_metadata_block_header_(iterator->file, &iterator->status, padding)) {
2884                 FLAC__metadata_object_delete(padding);
2885                 return false;
2886         }
2887
2888         if(!write_metadata_block_data_(iterator->file, &iterator->status, padding)) {
2889                 FLAC__metadata_object_delete(padding);
2890                 return false;
2891         }
2892
2893         FLAC__metadata_object_delete(padding);
2894
2895         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2896                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2897                 return false;
2898         }
2899
2900         return read_metadata_block_header_(iterator);
2901 }
2902
2903 FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append)
2904 {
2905         FILE *tempfile;
2906         char *tempfilename;
2907         int fixup_is_last_code = 0; /* 0 => no need to change any is_last flags */
2908         off_t fixup_is_last_flag_offset = -1;
2909
2910         FLAC__ASSERT(0 != block || append == false);
2911
2912         if(iterator->is_last) {
2913                 if(append) {
2914                         fixup_is_last_code = 1; /* 1 => clear the is_last flag at the following offset */
2915                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2916                 }
2917                 else if(0 == block) {
2918                         simple_iterator_push_(iterator);
2919                         if(!FLAC__metadata_simple_iterator_prev(iterator)) {
2920                                 (void)simple_iterator_pop_(iterator);
2921                                 return false;
2922                         }
2923                         fixup_is_last_code = -1; /* -1 => set the is_last the flag at the following offset */
2924                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2925                         if(!simple_iterator_pop_(iterator))
2926                                 return false;
2927                 }
2928         }
2929
2930         if(!simple_iterator_copy_file_prefix_(iterator, &tempfile, &tempfilename, append))
2931                 return false;
2932
2933         if(0 != block) {
2934                 if(!write_metadata_block_header_(tempfile, &iterator->status, block)) {
2935                         cleanup_tempfile_(&tempfile, &tempfilename);
2936                         return false;
2937                 }
2938
2939                 if(!write_metadata_block_data_(tempfile, &iterator->status, block)) {
2940                         cleanup_tempfile_(&tempfile, &tempfilename);
2941                         return false;
2942                 }
2943         }
2944
2945         if(!simple_iterator_copy_file_postfix_(iterator, &tempfile, &tempfilename, fixup_is_last_code, fixup_is_last_flag_offset, block==0))
2946                 return false;
2947
2948         if(append)
2949                 return FLAC__metadata_simple_iterator_next(iterator);
2950
2951         return true;
2952 }
2953
2954 void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator)
2955 {
2956         FLAC__ASSERT(iterator->depth+1 < SIMPLE_ITERATOR_MAX_PUSH_DEPTH);
2957         iterator->offset[iterator->depth+1] = iterator->offset[iterator->depth];
2958         iterator->depth++;
2959 }
2960
2961 FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator)
2962 {
2963         FLAC__ASSERT(iterator->depth > 0);
2964         iterator->depth--;
2965         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2966                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2967                 return false;
2968         }
2969
2970         return read_metadata_block_header_(iterator);
2971 }
2972
2973 /* return meanings:
2974  * 0: ok
2975  * 1: read error
2976  * 2: seek error
2977  * 3: not a FLAC file
2978  */
2979 unsigned seek_to_first_metadata_block_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb)
2980 {
2981         FLAC__byte buffer[4];
2982         size_t n;
2983         unsigned i;
2984
2985         FLAC__ASSERT(FLAC__STREAM_SYNC_LENGTH == sizeof(buffer));
2986
2987         /* skip any id3v2 tag */
2988         errno = 0;
2989         n = read_cb(buffer, 1, 4, handle);
2990         if(errno)
2991                 return 1;
2992         else if(n != 4)
2993                 return 3;
2994         else if(0 == memcmp(buffer, "ID3", 3)) {
2995                 unsigned tag_length = 0;
2996
2997                 /* skip to the tag length */
2998                 if(seek_cb(handle, 2, SEEK_CUR) < 0)
2999                         return 2;
3000
3001                 /* read the length */
3002                 for(i = 0; i < 4; i++) {
3003                         if(read_cb(buffer, 1, 1, handle) < 1 || buffer[0] & 0x80)
3004                                 return 1;
3005                         tag_length <<= 7;
3006                         tag_length |= (buffer[0] & 0x7f);
3007                 }
3008
3009                 /* skip the rest of the tag */
3010                 if(seek_cb(handle, tag_length, SEEK_CUR) < 0)
3011                         return 2;
3012
3013                 /* read the stream sync code */
3014                 errno = 0;
3015                 n = read_cb(buffer, 1, 4, handle);
3016                 if(errno)
3017                         return 1;
3018                 else if(n != 4)
3019                         return 3;
3020         }
3021
3022         /* check for the fLaC signature */
3023         if(0 == memcmp(FLAC__STREAM_SYNC_STRING, buffer, FLAC__STREAM_SYNC_LENGTH))
3024                 return 0;
3025         else
3026                 return 3;
3027 }
3028
3029 unsigned seek_to_first_metadata_block_(FILE *f)
3030 {
3031         return seek_to_first_metadata_block_cb_((FLAC__IOHandle)f, (FLAC__IOCallback_Read)fread, fseek_wrapper_);
3032 }
3033
3034 FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append)
3035 {
3036         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];
3037
3038         if(0 != fseeko(iterator->file, 0, SEEK_SET)) {
3039                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3040                 return false;
3041         }
3042         if(!open_tempfile_(iterator->filename, iterator->tempfile_path_prefix, tempfile, tempfilename, &iterator->status)) {
3043                 cleanup_tempfile_(tempfile, tempfilename);
3044                 return false;
3045         }
3046         if(!copy_n_bytes_from_file_(iterator->file, *tempfile, offset_end, &iterator->status)) {
3047                 cleanup_tempfile_(tempfile, tempfilename);
3048                 return false;
3049         }
3050
3051         return true;
3052 }
3053
3054 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)
3055 {
3056         off_t save_offset = iterator->offset[iterator->depth];
3057         FLAC__ASSERT(0 != *tempfile);
3058
3059         if(0 != fseeko(iterator->file, save_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length, SEEK_SET)) {
3060                 cleanup_tempfile_(tempfile, tempfilename);
3061                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3062                 return false;
3063         }
3064         if(!copy_remaining_bytes_from_file_(iterator->file, *tempfile, &iterator->status)) {
3065                 cleanup_tempfile_(tempfile, tempfilename);
3066                 return false;
3067         }
3068
3069         if(fixup_is_last_code != 0) {
3070                 /*
3071                  * if code == 1, it means a block was appended to the end so
3072                  *   we have to clear the is_last flag of the previous block
3073                  * if code == -1, it means the last block was deleted so
3074                  *   we have to set the is_last flag of the previous block
3075                  */
3076                 /* MAGIC NUMBERs here; we know the is_last flag is the high bit of the byte at this location */
3077                 FLAC__byte x;
3078                 if(0 != fseeko(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
3079                         cleanup_tempfile_(tempfile, tempfilename);
3080                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3081                         return false;
3082                 }
3083                 if(fread(&x, 1, 1, *tempfile) != 1) {
3084                         cleanup_tempfile_(tempfile, tempfilename);
3085                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3086                         return false;
3087                 }
3088                 if(fixup_is_last_code > 0) {
3089                         FLAC__ASSERT(x & 0x80);
3090                         x &= 0x7f;
3091                 }
3092                 else {
3093                         FLAC__ASSERT(!(x & 0x80));
3094                         x |= 0x80;
3095                 }
3096                 if(0 != fseeko(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
3097                         cleanup_tempfile_(tempfile, tempfilename);
3098                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3099                         return false;
3100                 }
3101                 if(local__fwrite(&x, 1, 1, *tempfile) != 1) {
3102                         cleanup_tempfile_(tempfile, tempfilename);
3103                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3104                         return false;
3105                 }
3106         }
3107
3108         (void)fclose(iterator->file);
3109
3110         if(!transport_tempfile_(iterator->filename, tempfile, tempfilename, &iterator->status))
3111                 return false;
3112
3113         if(iterator->has_stats)
3114                 set_file_stats_(iterator->filename, &iterator->stats);
3115
3116         if(!simple_iterator_prime_input_(iterator, !iterator->is_writable))
3117                 return false;
3118         if(backup) {
3119                 while(iterator->offset[iterator->depth] + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length < save_offset)
3120                         if(!FLAC__metadata_simple_iterator_next(iterator))
3121                                 return false;
3122                 return true;
3123         }
3124         else {
3125                 /* move the iterator to it's original block faster by faking a push, then doing a pop_ */
3126                 FLAC__ASSERT(iterator->depth == 0);
3127                 iterator->offset[0] = save_offset;
3128                 iterator->depth++;
3129                 return simple_iterator_pop_(iterator);
3130         }
3131 }
3132
3133 FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status)
3134 {
3135         FLAC__byte buffer[8192];
3136         size_t n;
3137
3138         FLAC__ASSERT(bytes >= 0);
3139         while(bytes > 0) {
3140                 n = min(sizeof(buffer), (size_t)bytes);
3141                 if(fread(buffer, 1, n, file) != n) {
3142                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3143                         return false;
3144                 }
3145                 if(local__fwrite(buffer, 1, n, tempfile) != n) {
3146                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3147                         return false;
3148                 }
3149                 bytes -= n;
3150         }
3151
3152         return true;
3153 }
3154
3155 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)
3156 {
3157         FLAC__byte buffer[8192];
3158         size_t n;
3159
3160         FLAC__ASSERT(bytes >= 0);
3161         while(bytes > 0) {
3162                 n = min(sizeof(buffer), (size_t)bytes);
3163                 if(read_cb(buffer, 1, n, handle) != n) {
3164                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3165                         return false;
3166                 }
3167                 if(temp_write_cb(buffer, 1, n, temp_handle) != n) {
3168                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3169                         return false;
3170                 }
3171                 bytes -= n;
3172         }
3173
3174         return true;
3175 }
3176
3177 FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status)
3178 {
3179         FLAC__byte buffer[8192];
3180         size_t n;
3181
3182         while(!feof(file)) {
3183                 n = fread(buffer, 1, sizeof(buffer), file);
3184                 if(n == 0 && !feof(file)) {
3185                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3186                         return false;
3187                 }
3188                 if(n > 0 && local__fwrite(buffer, 1, n, tempfile) != n) {
3189                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3190                         return false;
3191                 }
3192         }
3193
3194         return true;
3195 }
3196
3197 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)
3198 {
3199         FLAC__byte buffer[8192];
3200         size_t n;
3201
3202         while(!eof_cb(handle)) {
3203                 n = read_cb(buffer, 1, sizeof(buffer), handle);
3204                 if(n == 0 && !eof_cb(handle)) {
3205                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3206                         return false;
3207                 }
3208                 if(n > 0 && temp_write_cb(buffer, 1, n, temp_handle) != n) {
3209                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3210                         return false;
3211                 }
3212         }
3213
3214         return true;
3215 }
3216
3217 FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
3218 {
3219         static const char *tempfile_suffix = ".metadata_edit";
3220         if(0 == tempfile_path_prefix) {
3221                 if(0 == (*tempfilename = (char*)safe_malloc_add_3op_(strlen(filename), /*+*/strlen(tempfile_suffix), /*+*/1))) {
3222                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
3223                         return false;
3224                 }
3225                 strcpy(*tempfilename, filename);
3226                 strcat(*tempfilename, tempfile_suffix);
3227         }
3228         else {
3229                 const char *p = strrchr(filename, '/');
3230                 if(0 == p)
3231                         p = filename;
3232                 else
3233                         p++;
3234
3235                 if(0 == (*tempfilename = (char*)safe_malloc_add_4op_(strlen(tempfile_path_prefix), /*+*/strlen(p), /*+*/strlen(tempfile_suffix), /*+*/2))) {
3236                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
3237                         return false;
3238                 }
3239                 strcpy(*tempfilename, tempfile_path_prefix);
3240                 strcat(*tempfilename, "/");
3241                 strcat(*tempfilename, p);
3242                 strcat(*tempfilename, tempfile_suffix);
3243         }
3244
3245         if(0 == (*tempfile = fopen(*tempfilename, "w+b"))) {
3246                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
3247                 return false;
3248         }
3249
3250         return true;
3251 }
3252
3253 FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
3254 {
3255         FLAC__ASSERT(0 != filename);
3256         FLAC__ASSERT(0 != tempfile);
3257         FLAC__ASSERT(0 != *tempfile);
3258         FLAC__ASSERT(0 != tempfilename);
3259         FLAC__ASSERT(0 != *tempfilename);
3260         FLAC__ASSERT(0 != status);
3261
3262         (void)fclose(*tempfile);
3263         *tempfile = 0;
3264
3265 #if defined _MSC_VER || defined __BORLANDC__ || defined __MINGW32__ || defined __EMX__
3266         /* on some flavors of windows, rename() will fail if the destination already exists */
3267         if(unlink(filename) < 0) {
3268                 cleanup_tempfile_(tempfile, tempfilename);
3269                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR;
3270                 return false;
3271         }
3272 #endif
3273
3274         /*@@@ to fully support the tempfile_path_prefix we need to update this piece to actually copy across filesystems instead of just rename(): */
3275         if(0 != rename(*tempfilename, filename)) {
3276                 cleanup_tempfile_(tempfile, tempfilename);
3277                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR;
3278                 return false;
3279         }
3280
3281         cleanup_tempfile_(tempfile, tempfilename);
3282
3283         return true;
3284 }
3285
3286 void cleanup_tempfile_(FILE **tempfile, char **tempfilename)
3287 {
3288         if(0 != *tempfile) {
3289                 (void)fclose(*tempfile);
3290                 *tempfile = 0;
3291         }
3292
3293         if(0 != *tempfilename) {
3294                 (void)unlink(*tempfilename);
3295                 free(*tempfilename);
3296                 *tempfilename = 0;
3297         }
3298 }
3299
3300 FLAC__bool get_file_stats_(const char *filename, struct stat *stats)
3301 {
3302         FLAC__ASSERT(0 != filename);
3303         FLAC__ASSERT(0 != stats);
3304         return (0 == stat(filename, stats));
3305 }
3306
3307 void set_file_stats_(const char *filename, struct stat *stats)
3308 {
3309         struct utimbuf srctime;
3310
3311         FLAC__ASSERT(0 != filename);
3312         FLAC__ASSERT(0 != stats);
3313
3314         srctime.actime = stats->st_atime;
3315         srctime.modtime = stats->st_mtime;
3316         (void)chmod(filename, stats->st_mode);
3317         (void)utime(filename, &srctime);
3318 #if !defined _MSC_VER && !defined __BORLANDC__ && !defined __MINGW32__ && !defined __EMX__
3319         (void)chown(filename, stats->st_uid, -1);
3320         (void)chown(filename, -1, stats->st_gid);
3321 #endif
3322 }
3323
3324 int fseek_wrapper_(FLAC__IOHandle handle, FLAC__int64 offset, int whence)
3325 {
3326         return fseeko((FILE*)handle, (off_t)offset, whence);
3327 }
3328
3329 FLAC__int64 ftell_wrapper_(FLAC__IOHandle handle)
3330 {
3331         return ftello((FILE*)handle);
3332 }
3333
3334 FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status)
3335 {
3336         switch(status) {
3337                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK:
3338                         return FLAC__METADATA_CHAIN_STATUS_OK;
3339                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT:
3340                         return FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT;
3341                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE:
3342                         return FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
3343                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE:
3344                         return FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE;
3345                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE:
3346                         return FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE;
3347                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA:
3348                         return FLAC__METADATA_CHAIN_STATUS_BAD_METADATA;
3349                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR:
3350                         return FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
3351                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR:
3352                         return FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
3353                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR:
3354                         return FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
3355                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR:
3356                         return FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR;
3357                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR:
3358                         return FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR;
3359                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR:
3360                         return FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
3361                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR:
3362                 default:
3363                         return FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
3364         }
3365 }