src/libFLAC/metadata_iterators.c

   1 /* libFLAC - Free Lossless Audio Codec library
   2  * Copyright (C) 2001,2002,2003,2004,2005,2006  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 __MINGW32__
  42 #include <sys/utime.h> /* for utime() */
  43 #include <io.h> /* for chmod() */
  44 #include <sys/types.h> /* for off_t */
  45 #if _MSC_VER <= 1200 /* @@@ [2G limit] */
  46 #define fseeko fseek
  47 #define ftello ftell
  48 #endif
  49 #else
  50 #include <sys/types.h> /* some flavors of BSD (like OS X) require this to get time_t */
  51 #include <utime.h> /* for utime() */
  52 #include <unistd.h> /* for chown(), unlink() */
  53 #endif
  54 #include <sys/stat.h> /* for stat(), maybe chmod() */
  55
  56 #include "private/metadata.h"
  57
  58 #include "FLAC/assert.h"
  59 #include "FLAC/stream_decoder.h"
  60
  61 #ifdef max
  62 #undef max
  63 #endif
  64 #define max(a,b) ((a)>(b)?(a):(b))
  65 #ifdef min
  66 #undef min
  67 #endif
  68 #define min(a,b) ((a)<(b)?(a):(b))
  69
  70
  71 /****************************************************************************
  72  *
  73  * Local function declarations
  74  *
  75  ***************************************************************************/
  76
  77 static void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes);
  78 static void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes);
  79 static void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes);
  80 static FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes);
  81 static FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes);
  82 static FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes);
  83
  84 static FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator);
  85 static FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block);
  86 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);
  87 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);
  88 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_StreamInfo *block);
  89 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);
  90 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);
  91 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);
  92 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);
  93 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment *block);
  94 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet_Track *track);
  95 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet *block);
  96 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Picture *block);
  97 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);
  98
  99 static FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block);
 100 static FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block);
 101 static FLAC__bool write_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block);
 102 static FLAC__bool write_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block);
 103 static FLAC__bool write_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_StreamInfo *block);
 104 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);
 105 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);
 106 static FLAC__bool write_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_SeekTable *block);
 107 static FLAC__bool write_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_VorbisComment *block);
 108 static FLAC__bool write_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_CueSheet *block);
 109 static FLAC__bool write_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Picture *block);
 110 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);
 111
 112 static FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block);
 113 static FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last);
 114 static FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append);
 115
 116 static void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator);
 117 static FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator);
 118
 119 static unsigned seek_to_first_metadata_block_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb);
 120 static unsigned seek_to_first_metadata_block_(FILE *f);
 121
 122 static FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append);
 123 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);
 124
 125 static FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status);
 126 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);
 127 static FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status);
 128 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);
 129
 130 static FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status);
 131 static FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status);
 132 static void cleanup_tempfile_(FILE **tempfile, char **tempfilename);
 133
 134 static FLAC__bool get_file_stats_(const char *filename, struct stat *stats);
 135 static void set_file_stats_(const char *filename, struct stat *stats);
 136
 137 static int fseek_wrapper_(FLAC__IOHandle handle, FLAC__int64 offset, int whence);
 138 static FLAC__int64 ftell_wrapper_(FLAC__IOHandle handle);
 139
 140 static FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status);
 141
 142
 143 #ifdef FLAC__VALGRIND_TESTING
 144 static size_t local__fwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream)
 145 {
 146         size_t ret = fwrite(ptr, size, nmemb, stream);
 147         if(!ferror(stream))
 148                 fflush(stream);
 149         return ret;
 150 }
 151 #else
 152 #define local__fwrite fwrite
 153 #endif
 154
 155 /****************************************************************************
 156  *
 157  * Level 0 implementation
 158  *
 159  ***************************************************************************/
 160
 161 static FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data);
 162 static void metadata_callback_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data);
 163 static void error_callback_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data);
 164
 165 typedef struct {
 166         FLAC__bool got_error;
 167         FLAC__StreamMetadata *object;
 168 } level0_client_data;
 169
 170 static FLAC__StreamMetadata *get_one_metadata_block_(const char *filename, FLAC__MetadataType type)
 171 {
 172         level0_client_data cd;
 173         FLAC__StreamDecoder *decoder;
 174
 175         FLAC__ASSERT(0 != filename);
 176
 177         cd.got_error = false;
 178         cd.object = 0;
 179
 180         decoder = FLAC__stream_decoder_new();
 181
 182         if(0 == decoder)
 183                 return 0;
 184
 185         FLAC__stream_decoder_set_md5_checking(decoder, false);
 186         FLAC__stream_decoder_set_metadata_ignore_all(decoder);
 187         FLAC__stream_decoder_set_metadata_respond(decoder, type);
 188
 189         if(FLAC__stream_decoder_init_file(decoder, filename, write_callback_, metadata_callback_, error_callback_, &cd) != FLAC__STREAM_DECODER_INIT_STATUS_OK || cd.got_error) {
 190                 (void)FLAC__stream_decoder_finish(decoder);
 191                 FLAC__stream_decoder_delete(decoder);
 192                 return 0;
 193         }
 194
 195         if(!FLAC__stream_decoder_process_until_end_of_metadata(decoder) || cd.got_error) {
 196                 (void)FLAC__stream_decoder_finish(decoder);
 197                 FLAC__stream_decoder_delete(decoder);
 198                 if(0 != cd.object)
 199                         FLAC__metadata_object_delete(cd.object);
 200                 return 0;
 201         }
 202
 203         (void)FLAC__stream_decoder_finish(decoder);
 204         FLAC__stream_decoder_delete(decoder);
 205
 206         return cd.object;
 207 }
 208
 209 FLAC_API FLAC__bool FLAC__metadata_get_streaminfo(const char *filename, FLAC__StreamMetadata *streaminfo)
 210 {
 211         FLAC__StreamMetadata *object;
 212
 213         FLAC__ASSERT(0 != filename);
 214         FLAC__ASSERT(0 != streaminfo);
 215
 216         object = get_one_metadata_block_(filename, FLAC__METADATA_TYPE_STREAMINFO);
 217
 218         if (object) {
 219                 /* can just copy the contents since STREAMINFO has no internal structure */
 220                 *streaminfo = *object;
 221                 FLAC__metadata_object_delete(object);
 222                 return true;
 223         }
 224         else {
 225                 return false;
 226         }
 227 }
 228
 229 FLAC_API FLAC__bool FLAC__metadata_get_tags(const char *filename, FLAC__StreamMetadata **tags)
 230 {
 231         FLAC__ASSERT(0 != filename);
 232         FLAC__ASSERT(0 != tags);
 233
 234         *tags = get_one_metadata_block_(filename, FLAC__METADATA_TYPE_VORBIS_COMMENT);
 235
 236         return 0 != *tags;
 237 }
 238
 239 FLAC_API FLAC__bool FLAC__metadata_get_cuesheet(const char *filename, FLAC__StreamMetadata **cuesheet)
 240 {
 241         FLAC__ASSERT(0 != filename);
 242         FLAC__ASSERT(0 != cuesheet);
 243
 244         *cuesheet = get_one_metadata_block_(filename, FLAC__METADATA_TYPE_CUESHEET);
 245
 246         return 0 != *cuesheet;
 247 }
 248
 249 FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
 250 {
 251         (void)decoder, (void)frame, (void)buffer, (void)client_data;
 252
 253         return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;
 254 }
 255
 256 void metadata_callback_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
 257 {
 258         level0_client_data *cd = (level0_client_data *)client_data;
 259         (void)decoder;
 260
 261         /*
 262          * we assume we only get here when the one metadata block we were
 263          * looking for was passed to us
 264          */
 265         if(!cd->got_error && 0 == cd->object) {
 266                 if(0 == (cd->object = FLAC__metadata_object_clone(metadata)))
 267                         cd->got_error = true;
 268         }
 269 }
 270
 271 void error_callback_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
 272 {
 273         level0_client_data *cd = (level0_client_data *)client_data;
 274         (void)decoder;
 275
 276         if(status != FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC)
 277                 cd->got_error = true;
 278 }
 279
 280 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)
 281 {
 282         FLAC__Metadata_SimpleIterator *it;
 283         FLAC__uint64 max_area_seen = 0;
 284         FLAC__uint64 max_depth_seen = 0;
 285
 286         FLAC__ASSERT(0 != filename);
 287         FLAC__ASSERT(0 != picture);
 288
 289         *picture = 0;
 290
 291         it = FLAC__metadata_simple_iterator_new();
 292         if(0 == it)
 293                 return false;
 294         if(!FLAC__metadata_simple_iterator_init(it, filename, /*read_only=*/true, /*preserve_file_stats=*/true)) {
 295                 FLAC__metadata_simple_iterator_delete(it);
 296                 return false;
 297         }
 298         do {
 299                 if(FLAC__metadata_simple_iterator_get_block_type(it) == FLAC__METADATA_TYPE_PICTURE) {
 300                         FLAC__StreamMetadata *obj = FLAC__metadata_simple_iterator_get_block(it);
 301                         FLAC__uint64 area = (FLAC__uint64)obj->data.picture.width * (FLAC__uint64)obj->data.picture.height;
 302                         /* check constraints */
 303                         if(
 304                                 (type == (FLAC__StreamMetadata_Picture_Type)(-1) || type == obj->data.picture.type) &&
 305                                 (mime_type == 0 || !strcmp(mime_type, obj->data.picture.mime_type)) &&
 306                                 (description == 0 || !strcmp((const char *)description, (const char *)obj->data.picture.description)) &&
 307                                 obj->data.picture.width <= max_width &&
 308                                 obj->data.picture.height <= max_height &&
 309                                 obj->data.picture.depth <= max_depth &&
 310                                 obj->data.picture.colors <= max_colors &&
 311                                 (area > max_area_seen || (area == max_area_seen && obj->data.picture.depth > max_depth_seen))
 312                         ) {
 313                                 if(*picture)
 314                                         FLAC__metadata_object_delete(*picture);
 315                                 *picture = obj;
 316                                 max_area_seen = area;
 317                                 max_depth_seen = obj->data.picture.depth;
 318                         }
 319                         else {
 320                                 FLAC__metadata_object_delete(obj);
 321                         }
 322                 }
 323         } while(FLAC__metadata_simple_iterator_next(it));
 324
 325         FLAC__metadata_simple_iterator_delete(it);
 326
 327         return (0 != *picture);
 328 }
 329
 330
 331 /****************************************************************************
 332  *
 333  * Level 1 implementation
 334  *
 335  ***************************************************************************/
 336
 337 #define SIMPLE_ITERATOR_MAX_PUSH_DEPTH (1+4)
 338 /* 1 for initial offset, +4 for our own personal use */
 339
 340 struct FLAC__Metadata_SimpleIterator {
 341         FILE *file;
 342         char *filename, *tempfile_path_prefix;
 343         struct stat stats;
 344         FLAC__bool has_stats;
 345         FLAC__bool is_writable;
 346         FLAC__Metadata_SimpleIteratorStatus status;
 347         off_t offset[SIMPLE_ITERATOR_MAX_PUSH_DEPTH];
 348         off_t first_offset; /* this is the offset to the STREAMINFO block */
 349         unsigned depth;
 350         /* this is the metadata block header of the current block we are pointing to: */
 351         FLAC__bool is_last;
 352         FLAC__MetadataType type;
 353         unsigned length;
 354 };
 355
 356 FLAC_API const char * const FLAC__Metadata_SimpleIteratorStatusString[] = {
 357         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK",
 358         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT",
 359         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE",
 360         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE",
 361         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE",
 362         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA",
 363         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR",
 364         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR",
 365         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR",
 366         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR",
 367         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR",
 368         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR",
 369         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR"
 370 };
 371
 372
 373 FLAC_API FLAC__Metadata_SimpleIterator *FLAC__metadata_simple_iterator_new()
 374 {
 375         FLAC__Metadata_SimpleIterator *iterator = (FLAC__Metadata_SimpleIterator*)calloc(1, sizeof(FLAC__Metadata_SimpleIterator));
 376
 377         if(0 != iterator) {
 378                 iterator->file = 0;
 379                 iterator->filename = 0;
 380                 iterator->tempfile_path_prefix = 0;
 381                 iterator->has_stats = false;
 382                 iterator->is_writable = false;
 383                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
 384                 iterator->first_offset = iterator->offset[0] = -1;
 385                 iterator->depth = 0;
 386         }
 387
 388         return iterator;
 389 }
 390
 391 static void simple_iterator_free_guts_(FLAC__Metadata_SimpleIterator *iterator)
 392 {
 393         FLAC__ASSERT(0 != iterator);
 394
 395         if(0 != iterator->file) {
 396                 fclose(iterator->file);
 397                 iterator->file = 0;
 398                 if(iterator->has_stats)
 399                         set_file_stats_(iterator->filename, &iterator->stats);
 400         }
 401         if(0 != iterator->filename) {
 402                 free(iterator->filename);
 403                 iterator->filename = 0;
 404         }
 405         if(0 != iterator->tempfile_path_prefix) {
 406                 free(iterator->tempfile_path_prefix);
 407                 iterator->tempfile_path_prefix = 0;
 408         }
 409 }
 410
 411 FLAC_API void FLAC__metadata_simple_iterator_delete(FLAC__Metadata_SimpleIterator *iterator)
 412 {
 413         FLAC__ASSERT(0 != iterator);
 414
 415         simple_iterator_free_guts_(iterator);
 416         free(iterator);
 417 }
 418
 419 FLAC_API FLAC__Metadata_SimpleIteratorStatus FLAC__metadata_simple_iterator_status(FLAC__Metadata_SimpleIterator *iterator)
 420 {
 421         FLAC__Metadata_SimpleIteratorStatus status;
 422
 423         FLAC__ASSERT(0 != iterator);
 424
 425         status = iterator->status;
 426         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
 427         return status;
 428 }
 429
 430 static FLAC__bool simple_iterator_prime_input_(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool read_only)
 431 {
 432         unsigned ret;
 433
 434         FLAC__ASSERT(0 != iterator);
 435
 436         if(read_only || 0 == (iterator->file = fopen(iterator->filename, "r+b"))) {
 437                 iterator->is_writable = false;
 438                 if(read_only || errno == EACCES) {
 439                         if(0 == (iterator->file = fopen(iterator->filename, "rb"))) {
 440                                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
 441                                 return false;
 442                         }
 443                 }
 444                 else {
 445                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
 446                         return false;
 447                 }
 448         }
 449         else {
 450                 iterator->is_writable = true;
 451         }
 452
 453         ret = seek_to_first_metadata_block_(iterator->file);
 454         switch(ret) {
 455                 case 0:
 456                         iterator->depth = 0;
 457                         iterator->first_offset = iterator->offset[iterator->depth] = ftello(iterator->file);
 458                         return read_metadata_block_header_(iterator);
 459                 case 1:
 460                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
 461                         return false;
 462                 case 2:
 463                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 464                         return false;
 465                 case 3:
 466                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE;
 467                         return false;
 468                 default:
 469                         FLAC__ASSERT(0);
 470                         return false;
 471         }
 472 }
 473
 474 #if 0
 475 @@@ If we decide to finish implementing this, put this comment back in metadata.h
 476 /*
 477  * The 'tempfile_path_prefix' allows you to specify a directory where
 478  * tempfiles should go.  Remember that if your metadata edits cause the
 479  * FLAC file to grow, the entire file will have to be rewritten.  If
 480  * 'tempfile_path_prefix' is NULL, the temp file will be written in the
 481  * same directory as the original FLAC file.  This makes replacing the
 482  * original with the tempfile fast but requires extra space in the same
 483  * partition for the tempfile.  If space is a problem, you can pass a
 484  * directory name belonging to a different partition in
 485  * 'tempfile_path_prefix'.  Note that you should use the forward slash
 486  * '/' as the directory separator.  A trailing slash is not needed; it
 487  * will be added automatically.
 488  */
 489 FLAC__bool FLAC__metadata_simple_iterator_init(FLAC__Metadata_SimpleIterator *iterator, const char *filename, FLAC__bool preserve_file_stats, const char *tempfile_path_prefix);
 490 #endif
 491
 492 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)
 493 {
 494         const char *tempfile_path_prefix = 0; /*@@@ search for comments near 'rename(...)' for what it will take to finish implementing this */
 495
 496         FLAC__ASSERT(0 != iterator);
 497         FLAC__ASSERT(0 != filename);
 498
 499         simple_iterator_free_guts_(iterator);
 500
 501         if(!read_only && preserve_file_stats)
 502                 iterator->has_stats = get_file_stats_(filename, &iterator->stats);
 503
 504         if(0 == (iterator->filename = strdup(filename))) {
 505                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 506                 return false;
 507         }
 508         if(0 != tempfile_path_prefix && 0 == (iterator->tempfile_path_prefix = strdup(tempfile_path_prefix))) {
 509                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 510                 return false;
 511         }
 512
 513         return simple_iterator_prime_input_(iterator, read_only);
 514 }
 515
 516 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_is_writable(const FLAC__Metadata_SimpleIterator *iterator)
 517 {
 518         FLAC__ASSERT(0 != iterator);
 519         FLAC__ASSERT(0 != iterator->file);
 520
 521         return iterator->is_writable;
 522 }
 523
 524 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_next(FLAC__Metadata_SimpleIterator *iterator)
 525 {
 526         FLAC__ASSERT(0 != iterator);
 527         FLAC__ASSERT(0 != iterator->file);
 528
 529         if(iterator->is_last)
 530                 return false;
 531
 532         if(0 != fseeko(iterator->file, iterator->length, SEEK_CUR)) {
 533                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 534                 return false;
 535         }
 536
 537         iterator->offset[iterator->depth] = ftello(iterator->file);
 538
 539         return read_metadata_block_header_(iterator);
 540 }
 541
 542 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_prev(FLAC__Metadata_SimpleIterator *iterator)
 543 {
 544         off_t this_offset;
 545
 546         FLAC__ASSERT(0 != iterator);
 547         FLAC__ASSERT(0 != iterator->file);
 548
 549         if(iterator->offset[iterator->depth] == iterator->first_offset)
 550                 return false;
 551
 552         if(0 != fseeko(iterator->file, iterator->first_offset, SEEK_SET)) {
 553                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 554                 return false;
 555         }
 556         this_offset = iterator->first_offset;
 557         if(!read_metadata_block_header_(iterator))
 558                 return false;
 559
 560         /* we ignore any error from ftello() and catch it in fseeko() */
 561         while(ftello(iterator->file) + (off_t)iterator->length < iterator->offset[iterator->depth]) {
 562                 if(0 != fseeko(iterator->file, iterator->length, SEEK_CUR)) {
 563                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 564                         return false;
 565                 }
 566                 this_offset = ftello(iterator->file);
 567                 if(!read_metadata_block_header_(iterator))
 568                         return false;
 569         }
 570
 571         iterator->offset[iterator->depth] = this_offset;
 572
 573         return true;
 574 }
 575
 576 FLAC_API FLAC__MetadataType FLAC__metadata_simple_iterator_get_block_type(const FLAC__Metadata_SimpleIterator *iterator)
 577 {
 578         FLAC__ASSERT(0 != iterator);
 579         FLAC__ASSERT(0 != iterator->file);
 580
 581         return iterator->type;
 582 }
 583
 584 FLAC_API FLAC__StreamMetadata *FLAC__metadata_simple_iterator_get_block(FLAC__Metadata_SimpleIterator *iterator)
 585 {
 586         FLAC__StreamMetadata *block = FLAC__metadata_object_new(iterator->type);
 587
 588         FLAC__ASSERT(0 != iterator);
 589         FLAC__ASSERT(0 != iterator->file);
 590
 591         if(0 != block) {
 592                 block->is_last = iterator->is_last;
 593                 block->length = iterator->length;
 594
 595                 if(!read_metadata_block_data_(iterator, block)) {
 596                         FLAC__metadata_object_delete(block);
 597                         return 0;
 598                 }
 599
 600                 /* back up to the beginning of the block data to stay consistent */
 601                 if(0 != fseeko(iterator->file, iterator->offset[iterator->depth] + FLAC__STREAM_METADATA_HEADER_LENGTH, SEEK_SET)) {
 602                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 603                         FLAC__metadata_object_delete(block);
 604                         return 0;
 605                 }
 606         }
 607         else
 608                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 609
 610         return block;
 611 }
 612
 613 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_set_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding)
 614 {
 615         FLAC__ASSERT_DECLARATION(off_t debug_target_offset = iterator->offset[iterator->depth];)
 616         FLAC__bool ret;
 617
 618         FLAC__ASSERT(0 != iterator);
 619         FLAC__ASSERT(0 != iterator->file);
 620         FLAC__ASSERT(0 != block);
 621
 622         if(!iterator->is_writable) {
 623                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE;
 624                 return false;
 625         }
 626
 627         if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO || block->type == FLAC__METADATA_TYPE_STREAMINFO) {
 628                 if(iterator->type != block->type) {
 629                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 630                         return false;
 631                 }
 632         }
 633
 634         block->is_last = iterator->is_last;
 635
 636         if(iterator->length == block->length)
 637                 return write_metadata_block_stationary_(iterator, block);
 638         else if(iterator->length > block->length) {
 639                 if(use_padding && iterator->length >= FLAC__STREAM_METADATA_HEADER_LENGTH + block->length) {
 640                         ret = write_metadata_block_stationary_with_padding_(iterator, block, iterator->length - FLAC__STREAM_METADATA_HEADER_LENGTH - block->length, block->is_last);
 641                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 642                         FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 643                         return ret;
 644                 }
 645                 else {
 646                         ret = rewrite_whole_file_(iterator, block, /*append=*/false);
 647                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 648                         FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 649                         return ret;
 650                 }
 651         }
 652         else /* iterator->length < block->length */ {
 653                 unsigned padding_leftover = 0;
 654                 FLAC__bool padding_is_last = false;
 655                 if(use_padding) {
 656                         /* first see if we can even use padding */
 657                         if(iterator->is_last) {
 658                                 use_padding = false;
 659                         }
 660                         else {
 661                                 const unsigned extra_padding_bytes_required = block->length - iterator->length;
 662                                 simple_iterator_push_(iterator);
 663                                 if(!FLAC__metadata_simple_iterator_next(iterator)) {
 664                                         (void)simple_iterator_pop_(iterator);
 665                                         return false;
 666                                 }
 667                                 if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
 668                                         use_padding = false;
 669                                 }
 670                                 else {
 671                                         if(FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length == extra_padding_bytes_required) {
 672                                                 padding_leftover = 0;
 673                                                 block->is_last = iterator->is_last;
 674                                         }
 675                                         else if(iterator->length < extra_padding_bytes_required)
 676                                                 use_padding = false;
 677                                         else {
 678                                                 padding_leftover = FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length - extra_padding_bytes_required;
 679                                                 padding_is_last = iterator->is_last;
 680                                                 block->is_last = false;
 681                                         }
 682                                 }
 683                                 if(!simple_iterator_pop_(iterator))
 684                                         return false;
 685                         }
 686                 }
 687                 if(use_padding) {
 688                         if(padding_leftover == 0) {
 689                                 ret = write_metadata_block_stationary_(iterator, block);
 690                                 FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 691                                 FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 692                                 return ret;
 693                         }
 694                         else {
 695                                 FLAC__ASSERT(padding_leftover >= FLAC__STREAM_METADATA_HEADER_LENGTH);
 696                                 ret = write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover - FLAC__STREAM_METADATA_HEADER_LENGTH, padding_is_last);
 697                                 FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 698                                 FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 699                                 return ret;
 700                         }
 701                 }
 702                 else {
 703                         ret = rewrite_whole_file_(iterator, block, /*append=*/false);
 704                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 705                         FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 706                         return ret;
 707                 }
 708         }
 709 }
 710
 711 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_insert_block_after(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding)
 712 {
 713         unsigned padding_leftover = 0;
 714         FLAC__bool padding_is_last = false;
 715
 716         FLAC__ASSERT_DECLARATION(off_t debug_target_offset = iterator->offset[iterator->depth] + FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length;)
 717         FLAC__bool ret;
 718
 719         FLAC__ASSERT(0 != iterator);
 720         FLAC__ASSERT(0 != iterator->file);
 721         FLAC__ASSERT(0 != block);
 722
 723         if(!iterator->is_writable)
 724                 return false;
 725
 726         if(block->type == FLAC__METADATA_TYPE_STREAMINFO) {
 727                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 728                 return false;
 729         }
 730
 731         block->is_last = iterator->is_last;
 732
 733         if(use_padding) {
 734                 /* first see if we can even use padding */
 735                 if(iterator->is_last) {
 736                         use_padding = false;
 737                 }
 738                 else {
 739                         simple_iterator_push_(iterator);
 740                         if(!FLAC__metadata_simple_iterator_next(iterator)) {
 741                                 (void)simple_iterator_pop_(iterator);
 742                                 return false;
 743                         }
 744                         if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
 745                                 use_padding = false;
 746                         }
 747                         else {
 748                                 if(iterator->length == block->length) {
 749                                         padding_leftover = 0;
 750                                         block->is_last = iterator->is_last;
 751                                 }
 752                                 else if(iterator->length < FLAC__STREAM_METADATA_HEADER_LENGTH + block->length)
 753                                         use_padding = false;
 754                                 else {
 755                                         padding_leftover = iterator->length - block->length;
 756                                         padding_is_last = iterator->is_last;
 757                                         block->is_last = false;
 758                                 }
 759                         }
 760                         if(!simple_iterator_pop_(iterator))
 761                                 return false;
 762                 }
 763         }
 764         if(use_padding) {
 765                 /* move to the next block, which is suitable padding */
 766                 if(!FLAC__metadata_simple_iterator_next(iterator))
 767                         return false;
 768                 if(padding_leftover == 0) {
 769                         ret = write_metadata_block_stationary_(iterator, block);
 770                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 771                         FLAC__ASSERT(ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 772                         return ret;
 773                 }
 774                 else {
 775                         FLAC__ASSERT(padding_leftover >= FLAC__STREAM_METADATA_HEADER_LENGTH);
 776                         ret = write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover - FLAC__STREAM_METADATA_HEADER_LENGTH, padding_is_last);
 777                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 778                         FLAC__ASSERT(ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 779                         return ret;
 780                 }
 781         }
 782         else {
 783                 ret = rewrite_whole_file_(iterator, block, /*append=*/true);
 784                 FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 785                 FLAC__ASSERT(ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 786                 return ret;
 787         }
 788 }
 789
 790 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_delete_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool use_padding)
 791 {
 792         FLAC__ASSERT_DECLARATION(off_t debug_target_offset = iterator->offset[iterator->depth];)
 793         FLAC__bool ret;
 794
 795         if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO) {
 796                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 797                 return false;
 798         }
 799
 800         if(use_padding) {
 801                 FLAC__StreamMetadata *padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING);
 802                 if(0 == padding) {
 803                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 804                         return false;
 805                 }
 806                 padding->length = iterator->length;
 807                 if(!FLAC__metadata_simple_iterator_set_block(iterator, padding, false)) {
 808                         FLAC__metadata_object_delete(padding);
 809                         return false;
 810                 }
 811                 FLAC__metadata_object_delete(padding);
 812                 if(!FLAC__metadata_simple_iterator_prev(iterator))
 813                         return false;
 814                 FLAC__ASSERT(iterator->offset[iterator->depth] + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length == debug_target_offset);
 815                 FLAC__ASSERT(ftello(iterator->file) + (off_t)iterator->length == debug_target_offset);
 816                 return true;
 817         }
 818         else {
 819                 ret = rewrite_whole_file_(iterator, 0, /*append=*/false);
 820                 FLAC__ASSERT(iterator->offset[iterator->depth] + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length == debug_target_offset);
 821                 FLAC__ASSERT(ftello(iterator->file) + (off_t)iterator->length == debug_target_offset);
 822                 return ret;
 823         }
 824 }
 825
 826
 827
 828 /****************************************************************************
 829  *
 830  * Level 2 implementation
 831  *
 832  ***************************************************************************/
 833
 834
 835 typedef struct FLAC__Metadata_Node {
 836         FLAC__StreamMetadata *data;
 837         struct FLAC__Metadata_Node *prev, *next;
 838 } FLAC__Metadata_Node;
 839
 840 struct FLAC__Metadata_Chain {
 841         char *filename; /* will be NULL if using callbacks */
 842         FLAC__bool is_ogg;
 843         FLAC__Metadata_Node *head;
 844         FLAC__Metadata_Node *tail;
 845         unsigned nodes;
 846         FLAC__Metadata_ChainStatus status;
 847         off_t first_offset, last_offset;
 848         /*
 849          * This is the length of the chain initially read from the FLAC file.
 850          * it is used to compare against the current length to decide whether
 851          * or not the whole file has to be rewritten.
 852          */
 853         off_t initial_length;
 854         /* @@@ hacky, these are currently only needed by ogg reader */
 855         FLAC__IOHandle handle;
 856         FLAC__IOCallback_Read read_cb;
 857 };
 858
 859 struct FLAC__Metadata_Iterator {
 860         FLAC__Metadata_Chain *chain;
 861         FLAC__Metadata_Node *current;
 862 };
 863
 864 FLAC_API const char * const FLAC__Metadata_ChainStatusString[] = {
 865         "FLAC__METADATA_CHAIN_STATUS_OK",
 866         "FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT",
 867         "FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE",
 868         "FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE",
 869         "FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE",
 870         "FLAC__METADATA_CHAIN_STATUS_BAD_METADATA",
 871         "FLAC__METADATA_CHAIN_STATUS_READ_ERROR",
 872         "FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR",
 873         "FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR",
 874         "FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR",
 875         "FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR",
 876         "FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR",
 877         "FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR",
 878         "FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS",
 879         "FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH",
 880         "FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL"
 881 };
 882
 883
 884 static FLAC__Metadata_Node *node_new_()
 885 {
 886         return (FLAC__Metadata_Node*)calloc(1, sizeof(FLAC__Metadata_Node));
 887 }
 888
 889 static void node_delete_(FLAC__Metadata_Node *node)
 890 {
 891         FLAC__ASSERT(0 != node);
 892         if(0 != node->data)
 893                 FLAC__metadata_object_delete(node->data);
 894         free(node);
 895 }
 896
 897 static void chain_init_(FLAC__Metadata_Chain *chain)
 898 {
 899         FLAC__ASSERT(0 != chain);
 900
 901         chain->filename = 0;
 902         chain->is_ogg = false;
 903         chain->head = chain->tail = 0;
 904         chain->nodes = 0;
 905         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
 906         chain->initial_length = 0;
 907         chain->read_cb = 0;
 908 }
 909
 910 static void chain_clear_(FLAC__Metadata_Chain *chain)
 911 {
 912         FLAC__Metadata_Node *node, *next;
 913
 914         FLAC__ASSERT(0 != chain);
 915
 916         for(node = chain->head; node; ) {
 917                 next = node->next;
 918                 node_delete_(node);
 919                 node = next;
 920         }
 921
 922         if(0 != chain->filename)
 923                 free(chain->filename);
 924
 925         chain_init_(chain);
 926 }
 927
 928 static void chain_append_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 929 {
 930         FLAC__ASSERT(0 != chain);
 931         FLAC__ASSERT(0 != node);
 932         FLAC__ASSERT(0 != node->data);
 933
 934         node->next = node->prev = 0;
 935         node->data->is_last = true;
 936         if(0 != chain->tail)
 937                 chain->tail->data->is_last = false;
 938
 939         if(0 == chain->head)
 940                 chain->head = node;
 941         else {
 942                 FLAC__ASSERT(0 != chain->tail);
 943                 chain->tail->next = node;
 944                 node->prev = chain->tail;
 945         }
 946         chain->tail = node;
 947         chain->nodes++;
 948 }
 949
 950 static void chain_remove_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 951 {
 952         FLAC__ASSERT(0 != chain);
 953         FLAC__ASSERT(0 != node);
 954
 955         if(node == chain->head)
 956                 chain->head = node->next;
 957         else
 958                 node->prev->next = node->next;
 959
 960         if(node == chain->tail)
 961                 chain->tail = node->prev;
 962         else
 963                 node->next->prev = node->prev;
 964
 965         if(0 != chain->tail)
 966                 chain->tail->data->is_last = true;
 967
 968         chain->nodes--;
 969 }
 970
 971 static void chain_delete_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 972 {
 973         chain_remove_node_(chain, node);
 974         node_delete_(node);
 975 }
 976
 977 static off_t chain_calculate_length_(FLAC__Metadata_Chain *chain)
 978 {
 979         const FLAC__Metadata_Node *node;
 980         off_t length = 0;
 981         for(node = chain->head; node; node = node->next)
 982                 length += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
 983         return length;
 984 }
 985
 986 static void iterator_insert_node_(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Node *node)
 987 {
 988         FLAC__ASSERT(0 != node);
 989         FLAC__ASSERT(0 != node->data);
 990         FLAC__ASSERT(0 != iterator);
 991         FLAC__ASSERT(0 != iterator->current);
 992         FLAC__ASSERT(0 != iterator->chain);
 993         FLAC__ASSERT(0 != iterator->chain->head);
 994         FLAC__ASSERT(0 != iterator->chain->tail);
 995
 996         node->data->is_last = false;
 997
 998         node->prev = iterator->current->prev;
 999         node->next = iterator->current;
1000
1001         if(0 == node->prev)
1002                 iterator->chain->head = node;
1003         else
1004                 node->prev->next = node;
1005
1006         iterator->current->prev = node;
1007
1008         iterator->chain->nodes++;
1009 }
1010
1011 static void iterator_insert_node_after_(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Node *node)
1012 {
1013         FLAC__ASSERT(0 != node);
1014         FLAC__ASSERT(0 != node->data);
1015         FLAC__ASSERT(0 != iterator);
1016         FLAC__ASSERT(0 != iterator->current);
1017         FLAC__ASSERT(0 != iterator->chain);
1018         FLAC__ASSERT(0 != iterator->chain->head);
1019         FLAC__ASSERT(0 != iterator->chain->tail);
1020
1021         iterator->current->data->is_last = false;
1022
1023         node->prev = iterator->current;
1024         node->next = iterator->current->next;
1025
1026         if(0 == node->next)
1027                 iterator->chain->tail = node;
1028         else
1029                 node->next->prev = node;
1030
1031         node->prev->next = node;
1032
1033         iterator->chain->tail->data->is_last = true;
1034
1035         iterator->chain->nodes++;
1036 }
1037
1038 /* return true iff node and node->next are both padding */
1039 static FLAC__bool chain_merge_adjacent_padding_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
1040 {
1041         if(node->data->type == FLAC__METADATA_TYPE_PADDING && 0 != node->next && node->next->data->type == FLAC__METADATA_TYPE_PADDING) {
1042                 const unsigned growth = FLAC__STREAM_METADATA_HEADER_LENGTH + node->next->data->length;
1043                 node->data->length += growth;
1044
1045                 chain_delete_node_(chain, node->next);
1046                 return true;
1047         }
1048         else
1049                 return false;
1050 }
1051
1052 /* Returns the new length of the chain, or 0 if there was an error. */
1053 /* WATCHOUT: This can get called multiple times before a write, so
1054  * it should still work when this happens.
1055  */
1056 /* WATCHOUT: Make sure to also update the logic in
1057  * FLAC__metadata_chain_check_if_tempfile_needed() if the logic here changes.
1058  */
1059 static off_t chain_prepare_for_write_(FLAC__Metadata_Chain *chain, FLAC__bool use_padding)
1060 {
1061         off_t current_length = chain_calculate_length_(chain);
1062
1063         if(use_padding) {
1064                 /* if the metadata shrank and the last block is padding, we just extend the last padding block */
1065                 if(current_length < chain->initial_length && chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1066                         const off_t delta = chain->initial_length - current_length;
1067                         chain->tail->data->length += delta;
1068                         current_length += delta;
1069                         FLAC__ASSERT(current_length == chain->initial_length);
1070                 }
1071                 /* if the metadata shrank more than 4 bytes then there's room to add another padding block */
1072                 else if(current_length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH <= chain->initial_length) {
1073                         FLAC__StreamMetadata *padding;
1074                         FLAC__Metadata_Node *node;
1075                         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING))) {
1076                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1077                                 return 0;
1078                         }
1079                         padding->length = chain->initial_length - (FLAC__STREAM_METADATA_HEADER_LENGTH + current_length);
1080                         if(0 == (node = node_new_())) {
1081                                 FLAC__metadata_object_delete(padding);
1082                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1083                                 return 0;
1084                         }
1085                         node->data = padding;
1086                         chain_append_node_(chain, node);
1087                         current_length = chain_calculate_length_(chain);
1088                         FLAC__ASSERT(current_length == chain->initial_length);
1089                 }
1090                 /* 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 */
1091                 else if(current_length > chain->initial_length) {
1092                         const off_t delta = current_length - chain->initial_length;
1093                         if(chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1094                                 /* if the delta is exactly the size of the last padding block, remove the padding block */
1095                                 if((off_t)chain->tail->data->length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH == delta) {
1096                                         chain_delete_node_(chain, chain->tail);
1097                                         current_length = chain_calculate_length_(chain);
1098                                         FLAC__ASSERT(current_length == chain->initial_length);
1099                                 }
1100                                 /* if there is at least 'delta' bytes of padding, trim the padding down */
1101                                 else if((off_t)chain->tail->data->length >= delta) {
1102                                         chain->tail->data->length -= delta;
1103                                         current_length -= delta;
1104                                         FLAC__ASSERT(current_length == chain->initial_length);
1105                                 }
1106                         }
1107                 }
1108         }
1109
1110         return current_length;
1111 }
1112
1113 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)
1114 {
1115         FLAC__Metadata_Node *node;
1116
1117         FLAC__ASSERT(0 != chain);
1118
1119         /* we assume we're already at the beginning of the file */
1120
1121         switch(seek_to_first_metadata_block_cb_(handle, read_cb, seek_cb)) {
1122                 case 0:
1123                         break;
1124                 case 1:
1125                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1126                         return false;
1127                 case 2:
1128                         chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1129                         return false;
1130                 case 3:
1131                         chain->status = FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE;
1132                         return false;
1133                 default:
1134                         FLAC__ASSERT(0);
1135                         return false;
1136         }
1137
1138         {
1139                 FLAC__int64 pos = tell_cb(handle);
1140                 if(pos < 0) {
1141                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1142                         return false;
1143                 }
1144                 chain->first_offset = (off_t)pos;
1145         }
1146
1147         {
1148                 FLAC__bool is_last;
1149                 FLAC__MetadataType type;
1150                 unsigned length;
1151
1152                 do {
1153                         node = node_new_();
1154                         if(0 == node) {
1155                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1156                                 return false;
1157                         }
1158
1159                         if(!read_metadata_block_header_cb_(handle, read_cb, &is_last, &type, &length)) {
1160                                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1161                                 return false;
1162                         }
1163
1164                         node->data = FLAC__metadata_object_new(type);
1165                         if(0 == node->data) {
1166                                 node_delete_(node);
1167                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1168                                 return false;
1169                         }
1170
1171                         node->data->is_last = is_last;
1172                         node->data->length = length;
1173
1174                         chain->status = get_equivalent_status_(read_metadata_block_data_cb_(handle, read_cb, seek_cb, node->data));
1175                         if(chain->status != FLAC__METADATA_CHAIN_STATUS_OK) {
1176                                 node_delete_(node);
1177                                 return false;
1178                         }
1179                         chain_append_node_(chain, node);
1180                 } while(!is_last);
1181         }
1182
1183         {
1184                 FLAC__int64 pos = tell_cb(handle);
1185                 if(pos < 0) {
1186                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1187                         return false;
1188                 }
1189                 chain->last_offset = (off_t)pos;
1190         }
1191
1192         chain->initial_length = chain_calculate_length_(chain);
1193
1194         return true;
1195 }
1196
1197 FLAC__StreamDecoderReadStatus chain_read_ogg_read_cb_(const FLAC__StreamDecoder *decoder, FLAC__byte buffer[], size_t *bytes, void *client_data)
1198 {
1199         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1200         (void)decoder;
1201         if(*bytes > 0 && chain->status == FLAC__METADATA_CHAIN_STATUS_OK) {
1202                 *bytes = chain->read_cb(buffer, sizeof(FLAC__byte), *bytes, chain->handle);
1203                 if(*bytes == 0)
1204                         return FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM;
1205                 else
1206                         return FLAC__STREAM_DECODER_READ_STATUS_CONTINUE;
1207         }
1208         else
1209                 return FLAC__STREAM_DECODER_READ_STATUS_ABORT;
1210 }
1211
1212 static FLAC__StreamDecoderWriteStatus chain_read_ogg_write_cb_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
1213 {
1214         (void)decoder, (void)frame, (void)buffer, (void)client_data;
1215         return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
1216 }
1217
1218 static void chain_read_ogg_metadata_cb_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
1219 {
1220         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1221         FLAC__Metadata_Node *node;
1222
1223         (void)decoder;
1224
1225         node = node_new_();
1226         if(0 == node) {
1227                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1228                 return;
1229         }
1230
1231         node->data = FLAC__metadata_object_clone(metadata);
1232         if(0 == node->data) {
1233                 node_delete_(node);
1234                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1235                 return;
1236         }
1237
1238         chain_append_node_(chain, node);
1239 }
1240
1241 static void chain_read_ogg_error_cb_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
1242 {
1243         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1244         (void)decoder, (void)status;
1245         chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1246 }
1247
1248 static FLAC__bool chain_read_ogg_cb_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb)
1249 {
1250         FLAC__StreamDecoder *decoder;
1251
1252         FLAC__ASSERT(0 != chain);
1253
1254         /* we assume we're already at the beginning of the file */
1255
1256         chain->handle = handle;
1257         chain->read_cb = read_cb;
1258         if(0 == (decoder = FLAC__stream_decoder_new())) {
1259                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1260                 return false;
1261         }
1262         FLAC__stream_decoder_set_metadata_respond_all(decoder);
1263         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) {
1264                 FLAC__stream_decoder_delete(decoder);
1265                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1266                 return false;
1267         }
1268
1269         chain->first_offset = 0; /*@@@ wrong; will need to be set correctly to implement metadata writing for Ogg FLAC */
1270
1271         if(!FLAC__stream_decoder_process_until_end_of_metadata(decoder))
1272                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1273         if(chain->status != FLAC__METADATA_CHAIN_STATUS_OK) {
1274                 FLAC__stream_decoder_delete(decoder);
1275                 return false;
1276         }
1277
1278         FLAC__stream_decoder_delete(decoder);
1279
1280         chain->last_offset = 0; /*@@@ wrong; will need to be set correctly to implement metadata writing for Ogg FLAC */
1281
1282         chain->initial_length = chain_calculate_length_(chain);
1283
1284         return true;
1285 }
1286
1287 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)
1288 {
1289         FLAC__Metadata_Node *node;
1290
1291         FLAC__ASSERT(0 != chain);
1292         FLAC__ASSERT(0 != chain->head);
1293
1294         if(0 != seek_cb(handle, chain->first_offset, SEEK_SET)) {
1295                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1296                 return false;
1297         }
1298
1299         for(node = chain->head; node; node = node->next) {
1300                 if(!write_metadata_block_header_cb_(handle, write_cb, node->data)) {
1301                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1302                         return false;
1303                 }
1304                 if(!write_metadata_block_data_cb_(handle, write_cb, node->data)) {
1305                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1306                         return false;
1307                 }
1308         }
1309
1310         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1311
1312         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
1313         return true;
1314 }
1315
1316 static FLAC__bool chain_rewrite_metadata_in_place_(FLAC__Metadata_Chain *chain)
1317 {
1318         FILE *file;
1319         FLAC__bool ret;
1320
1321         FLAC__ASSERT(0 != chain->filename);
1322
1323         if(0 == (file = fopen(chain->filename, "r+b"))) {
1324                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1325                 return false;
1326         }
1327
1328         /* chain_rewrite_metadata_in_place_cb_() sets chain->status for us */
1329         ret = chain_rewrite_metadata_in_place_cb_(chain, (FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, fseek_wrapper_);
1330
1331         fclose(file);
1332
1333         return ret;
1334 }
1335
1336 static FLAC__bool chain_rewrite_file_(FLAC__Metadata_Chain *chain, const char *tempfile_path_prefix)
1337 {
1338         FILE *f, *tempfile;
1339         char *tempfilename;
1340         FLAC__Metadata_SimpleIteratorStatus status;
1341         const FLAC__Metadata_Node *node;
1342
1343         FLAC__ASSERT(0 != chain);
1344         FLAC__ASSERT(0 != chain->filename);
1345         FLAC__ASSERT(0 != chain->head);
1346
1347         /* copy the file prefix (data up to first metadata block */
1348         if(0 == (f = fopen(chain->filename, "rb"))) {
1349                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1350                 return false;
1351         }
1352         if(!open_tempfile_(chain->filename, tempfile_path_prefix, &tempfile, &tempfilename, &status)) {
1353                 chain->status = get_equivalent_status_(status);
1354                 cleanup_tempfile_(&tempfile, &tempfilename);
1355                 return false;
1356         }
1357         if(!copy_n_bytes_from_file_(f, tempfile, chain->first_offset, &status)) {
1358                 chain->status = get_equivalent_status_(status);
1359                 cleanup_tempfile_(&tempfile, &tempfilename);
1360                 return false;
1361         }
1362
1363         /* write the metadata */
1364         for(node = chain->head; node; node = node->next) {
1365                 if(!write_metadata_block_header_(tempfile, &status, node->data)) {
1366                         chain->status = get_equivalent_status_(status);
1367                         return false;
1368                 }
1369                 if(!write_metadata_block_data_(tempfile, &status, node->data)) {
1370                         chain->status = get_equivalent_status_(status);
1371                         return false;
1372                 }
1373         }
1374         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1375
1376         /* copy the file postfix (everything after the metadata) */
1377         if(0 != fseeko(f, chain->last_offset, SEEK_SET)) {
1378                 cleanup_tempfile_(&tempfile, &tempfilename);
1379                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1380                 return false;
1381         }
1382         if(!copy_remaining_bytes_from_file_(f, tempfile, &status)) {
1383                 cleanup_tempfile_(&tempfile, &tempfilename);
1384                 chain->status = get_equivalent_status_(status);
1385                 return false;
1386         }
1387
1388         /* move the tempfile on top of the original */
1389         (void)fclose(f);
1390         if(!transport_tempfile_(chain->filename, &tempfile, &tempfilename, &status))
1391                 return false;
1392
1393         return true;
1394 }
1395
1396 /* assumes 'handle' is already at beginning of file */
1397 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)
1398 {
1399         FLAC__Metadata_SimpleIteratorStatus status;
1400         const FLAC__Metadata_Node *node;
1401
1402         FLAC__ASSERT(0 != chain);
1403         FLAC__ASSERT(0 == chain->filename);
1404         FLAC__ASSERT(0 != chain->head);
1405
1406         /* copy the file prefix (data up to first metadata block */
1407         if(!copy_n_bytes_from_file_cb_(handle, read_cb, temp_handle, temp_write_cb, chain->first_offset, &status)) {
1408                 chain->status = get_equivalent_status_(status);
1409                 return false;
1410         }
1411
1412         /* write the metadata */
1413         for(node = chain->head; node; node = node->next) {
1414                 if(!write_metadata_block_header_cb_(temp_handle, temp_write_cb, node->data)) {
1415                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1416                         return false;
1417                 }
1418                 if(!write_metadata_block_data_cb_(temp_handle, temp_write_cb, node->data)) {
1419                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1420                         return false;
1421                 }
1422         }
1423         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1424
1425         /* copy the file postfix (everything after the metadata) */
1426         if(0 != seek_cb(handle, chain->last_offset, SEEK_SET)) {
1427                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1428                 return false;
1429         }
1430         if(!copy_remaining_bytes_from_file_cb_(handle, read_cb, eof_cb, temp_handle, temp_write_cb, &status)) {
1431                 chain->status = get_equivalent_status_(status);
1432                 return false;
1433         }
1434
1435         return true;
1436 }
1437
1438 FLAC_API FLAC__Metadata_Chain *FLAC__metadata_chain_new()
1439 {
1440         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)calloc(1, sizeof(FLAC__Metadata_Chain));
1441
1442         if(0 != chain)
1443                 chain_init_(chain);
1444
1445         return chain;
1446 }
1447
1448 FLAC_API void FLAC__metadata_chain_delete(FLAC__Metadata_Chain *chain)
1449 {
1450         FLAC__ASSERT(0 != chain);
1451
1452         chain_clear_(chain);
1453
1454         free(chain);
1455 }
1456
1457 FLAC_API FLAC__Metadata_ChainStatus FLAC__metadata_chain_status(FLAC__Metadata_Chain *chain)
1458 {
1459         FLAC__Metadata_ChainStatus status;
1460
1461         FLAC__ASSERT(0 != chain);
1462
1463         status = chain->status;
1464         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
1465         return status;
1466 }
1467
1468 static FLAC__bool chain_read_(FLAC__Metadata_Chain *chain, const char *filename, FLAC__bool is_ogg)
1469 {
1470         FILE *file;
1471         FLAC__bool ret;
1472
1473         FLAC__ASSERT(0 != chain);
1474         FLAC__ASSERT(0 != filename);
1475
1476         chain_clear_(chain);
1477
1478         if(0 == (chain->filename = strdup(filename))) {
1479                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1480                 return false;
1481         }
1482
1483         chain->is_ogg = is_ogg;
1484
1485         if(0 == (file = fopen(filename, "rb"))) {
1486                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1487                 return false;
1488         }
1489
1490         /* the function also sets chain->status for us */
1491         ret = is_ogg?
1492                 chain_read_ogg_cb_(chain, file, (FLAC__IOCallback_Read)fread) :
1493                 chain_read_cb_(chain, file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, ftell_wrapper_)
1494         ;
1495
1496         fclose(file);
1497
1498         return ret;
1499 }
1500
1501 FLAC_API FLAC__bool FLAC__metadata_chain_read(FLAC__Metadata_Chain *chain, const char *filename)
1502 {
1503         return chain_read_(chain, filename, /*is_ogg=*/false);
1504 }
1505
1506 FLAC_API FLAC__bool FLAC__metadata_chain_read_ogg(FLAC__Metadata_Chain *chain, const char *filename)
1507 {
1508         return chain_read_(chain, filename, /*is_ogg=*/true);
1509 }
1510
1511 static FLAC__bool chain_read_with_callbacks_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks, FLAC__bool is_ogg)
1512 {
1513         FLAC__bool ret;
1514
1515         FLAC__ASSERT(0 != chain);
1516
1517         chain_clear_(chain);
1518
1519         if (0 == callbacks.read || 0 == callbacks.seek || 0 == callbacks.tell) {
1520                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1521                 return false;
1522         }
1523
1524         chain->is_ogg = is_ogg;
1525
1526         /* rewind */
1527         if(0 != callbacks.seek(handle, 0, SEEK_SET)) {
1528                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1529                 return false;
1530         }
1531
1532         /* the function also sets chain->status for us */
1533         ret = is_ogg?
1534                 chain_read_ogg_cb_(chain, handle, callbacks.read) :
1535                 chain_read_cb_(chain, handle, callbacks.read, callbacks.seek, callbacks.tell)
1536         ;
1537
1538         return ret;
1539 }
1540
1541 FLAC_API FLAC__bool FLAC__metadata_chain_read_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1542 {
1543         return chain_read_with_callbacks_(chain, handle, callbacks, /*is_ogg=*/false);
1544 }
1545
1546 FLAC_API FLAC__bool FLAC__metadata_chain_read_ogg_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1547 {
1548         return chain_read_with_callbacks_(chain, handle, callbacks, /*is_ogg=*/true);
1549 }
1550
1551 FLAC_API FLAC__bool FLAC__metadata_chain_check_if_tempfile_needed(FLAC__Metadata_Chain *chain, FLAC__bool use_padding)
1552 {
1553         /* This does all the same checks that are in chain_prepare_for_write_()
1554          * but doesn't actually alter the chain.  Make sure to update the logic
1555          * here if chain_prepare_for_write_() changes.
1556          */
1557         const off_t current_length = chain_calculate_length_(chain);
1558
1559         FLAC__ASSERT(0 != chain);
1560
1561         if(use_padding) {
1562                 /* if the metadata shrank and the last block is padding, we just extend the last padding block */
1563                 if(current_length < chain->initial_length && chain->tail->data->type == FLAC__METADATA_TYPE_PADDING)
1564                         return false;
1565                 /* if the metadata shrank more than 4 bytes then there's room to add another padding block */
1566                 else if(current_length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH <= chain->initial_length)
1567                         return false;
1568                 /* 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 */
1569                 else if(current_length > chain->initial_length) {
1570                         const off_t delta = current_length - chain->initial_length;
1571                         if(chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1572                                 /* if the delta is exactly the size of the last padding block, remove the padding block */
1573                                 if((off_t)chain->tail->data->length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH == delta)
1574                                         return false;
1575                                 /* if there is at least 'delta' bytes of padding, trim the padding down */
1576                                 else if((off_t)chain->tail->data->length >= delta)
1577                                         return false;
1578                         }
1579                 }
1580         }
1581
1582         return (current_length != chain->initial_length);
1583 }
1584
1585 FLAC_API FLAC__bool FLAC__metadata_chain_write(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__bool preserve_file_stats)
1586 {
1587         struct stat stats;
1588         const char *tempfile_path_prefix = 0;
1589         off_t current_length;
1590
1591         FLAC__ASSERT(0 != chain);
1592
1593         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1594                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1595                 return false;
1596         }
1597
1598         if (0 == chain->filename) {
1599                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1600                 return false;
1601         }
1602
1603         current_length = chain_prepare_for_write_(chain, use_padding);
1604
1605         /* a return value of 0 means there was an error; chain->status is already set */
1606         if (0 == current_length)
1607                 return false;
1608
1609         if(preserve_file_stats)
1610                 get_file_stats_(chain->filename, &stats);
1611
1612         if(current_length == chain->initial_length) {
1613                 if(!chain_rewrite_metadata_in_place_(chain))
1614                         return false;
1615         }
1616         else {
1617                 if(!chain_rewrite_file_(chain, tempfile_path_prefix))
1618                         return false;
1619
1620                 /* recompute lengths and offsets */
1621                 {
1622                         const FLAC__Metadata_Node *node;
1623                         chain->initial_length = current_length;
1624                         chain->last_offset = chain->first_offset;
1625                         for(node = chain->head; node; node = node->next)
1626                                 chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1627                 }
1628         }
1629
1630         if(preserve_file_stats)
1631                 set_file_stats_(chain->filename, &stats);
1632
1633         return true;
1634 }
1635
1636 FLAC_API FLAC__bool FLAC__metadata_chain_write_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1637 {
1638         off_t current_length;
1639
1640         FLAC__ASSERT(0 != chain);
1641
1642         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1643                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1644                 return false;
1645         }
1646
1647         if (0 != chain->filename) {
1648                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1649                 return false;
1650         }
1651
1652         if (0 == callbacks.write || 0 == callbacks.seek) {
1653                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1654                 return false;
1655         }
1656
1657         if (FLAC__metadata_chain_check_if_tempfile_needed(chain, use_padding)) {
1658                 chain->status = FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL;
1659                 return false;
1660         }
1661
1662         current_length = chain_prepare_for_write_(chain, use_padding);
1663
1664         /* a return value of 0 means there was an error; chain->status is already set */
1665         if (0 == current_length)
1666                 return false;
1667
1668         FLAC__ASSERT(current_length == chain->initial_length);
1669
1670         return chain_rewrite_metadata_in_place_cb_(chain, handle, callbacks.write, callbacks.seek);
1671 }
1672
1673 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)
1674 {
1675         off_t current_length;
1676
1677         FLAC__ASSERT(0 != chain);
1678
1679         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1680                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1681                 return false;
1682         }
1683
1684         if (0 != chain->filename) {
1685                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1686                 return false;
1687         }
1688
1689         if (0 == callbacks.read || 0 == callbacks.seek || 0 == callbacks.eof) {
1690                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1691                 return false;
1692         }
1693         if (0 == temp_callbacks.write) {
1694                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1695                 return false;
1696         }
1697
1698         if (!FLAC__metadata_chain_check_if_tempfile_needed(chain, use_padding)) {
1699                 chain->status = FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL;
1700                 return false;
1701         }
1702
1703         current_length = chain_prepare_for_write_(chain, use_padding);
1704
1705         /* a return value of 0 means there was an error; chain->status is already set */
1706         if (0 == current_length)
1707                 return false;
1708
1709         FLAC__ASSERT(current_length != chain->initial_length);
1710
1711         /* rewind */
1712         if(0 != callbacks.seek(handle, 0, SEEK_SET)) {
1713                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1714                 return false;
1715         }
1716
1717         if(!chain_rewrite_file_cb_(chain, handle, callbacks.read, callbacks.seek, callbacks.eof, temp_handle, temp_callbacks.write))
1718                 return false;
1719
1720         /* recompute lengths and offsets */
1721         {
1722                 const FLAC__Metadata_Node *node;
1723                 chain->initial_length = current_length;
1724                 chain->last_offset = chain->first_offset;
1725                 for(node = chain->head; node; node = node->next)
1726                         chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1727         }
1728
1729         return true;
1730 }
1731
1732 FLAC_API void FLAC__metadata_chain_merge_padding(FLAC__Metadata_Chain *chain)
1733 {
1734         FLAC__Metadata_Node *node;
1735
1736         FLAC__ASSERT(0 != chain);
1737
1738         for(node = chain->head; node; ) {
1739                 if(!chain_merge_adjacent_padding_(chain, node))
1740                         node = node->next;
1741         }
1742 }
1743
1744 FLAC_API void FLAC__metadata_chain_sort_padding(FLAC__Metadata_Chain *chain)
1745 {
1746         FLAC__Metadata_Node *node, *save;
1747         unsigned i;
1748
1749         FLAC__ASSERT(0 != chain);
1750
1751         /*
1752          * Don't try and be too smart... this simple algo is good enough for
1753          * the small number of nodes that we deal with.
1754          */
1755         for(i = 0, node = chain->head; i < chain->nodes; i++) {
1756                 if(node->data->type == FLAC__METADATA_TYPE_PADDING) {
1757                         save = node->next;
1758                         chain_remove_node_(chain, node);
1759                         chain_append_node_(chain, node);
1760                         node = save;
1761                 }
1762                 else {
1763                         node = node->next;
1764                 }
1765         }
1766
1767         FLAC__metadata_chain_merge_padding(chain);
1768 }
1769
1770
1771 FLAC_API FLAC__Metadata_Iterator *FLAC__metadata_iterator_new()
1772 {
1773         FLAC__Metadata_Iterator *iterator = (FLAC__Metadata_Iterator*)calloc(1, sizeof(FLAC__Metadata_Iterator));
1774
1775         /* calloc() implies:
1776                 iterator->current = 0;
1777                 iterator->chain = 0;
1778         */
1779
1780         return iterator;
1781 }
1782
1783 FLAC_API void FLAC__metadata_iterator_delete(FLAC__Metadata_Iterator *iterator)
1784 {
1785         FLAC__ASSERT(0 != iterator);
1786
1787         free(iterator);
1788 }
1789
1790 FLAC_API void FLAC__metadata_iterator_init(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Chain *chain)
1791 {
1792         FLAC__ASSERT(0 != iterator);
1793         FLAC__ASSERT(0 != chain);
1794         FLAC__ASSERT(0 != chain->head);
1795
1796         iterator->chain = chain;
1797         iterator->current = chain->head;
1798 }
1799
1800 FLAC_API FLAC__bool FLAC__metadata_iterator_next(FLAC__Metadata_Iterator *iterator)
1801 {
1802         FLAC__ASSERT(0 != iterator);
1803
1804         if(0 == iterator->current || 0 == iterator->current->next)
1805                 return false;
1806
1807         iterator->current = iterator->current->next;
1808         return true;
1809 }
1810
1811 FLAC_API FLAC__bool FLAC__metadata_iterator_prev(FLAC__Metadata_Iterator *iterator)
1812 {
1813         FLAC__ASSERT(0 != iterator);
1814
1815         if(0 == iterator->current || 0 == iterator->current->prev)
1816                 return false;
1817
1818         iterator->current = iterator->current->prev;
1819         return true;
1820 }
1821
1822 FLAC_API FLAC__MetadataType FLAC__metadata_iterator_get_block_type(const FLAC__Metadata_Iterator *iterator)
1823 {
1824         FLAC__ASSERT(0 != iterator);
1825         FLAC__ASSERT(0 != iterator->current);
1826         FLAC__ASSERT(0 != iterator->current->data);
1827
1828         return iterator->current->data->type;
1829 }
1830
1831 FLAC_API FLAC__StreamMetadata *FLAC__metadata_iterator_get_block(FLAC__Metadata_Iterator *iterator)
1832 {
1833         FLAC__ASSERT(0 != iterator);
1834         FLAC__ASSERT(0 != iterator->current);
1835
1836         return iterator->current->data;
1837 }
1838
1839 FLAC_API FLAC__bool FLAC__metadata_iterator_set_block(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1840 {
1841         FLAC__ASSERT(0 != iterator);
1842         FLAC__ASSERT(0 != block);
1843         return FLAC__metadata_iterator_delete_block(iterator, false) && FLAC__metadata_iterator_insert_block_after(iterator, block);
1844 }
1845
1846 FLAC_API FLAC__bool FLAC__metadata_iterator_delete_block(FLAC__Metadata_Iterator *iterator, FLAC__bool replace_with_padding)
1847 {
1848         FLAC__Metadata_Node *save;
1849
1850         FLAC__ASSERT(0 != iterator);
1851         FLAC__ASSERT(0 != iterator->current);
1852
1853         if(0 == iterator->current->prev) {
1854                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1855                 return false;
1856         }
1857
1858         save = iterator->current->prev;
1859
1860         if(replace_with_padding) {
1861                 FLAC__metadata_object_delete_data(iterator->current->data);
1862                 iterator->current->data->type = FLAC__METADATA_TYPE_PADDING;
1863         }
1864         else {
1865                 chain_delete_node_(iterator->chain, iterator->current);
1866         }
1867
1868         iterator->current = save;
1869         return true;
1870 }
1871
1872 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_before(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1873 {
1874         FLAC__Metadata_Node *node;
1875
1876         FLAC__ASSERT(0 != iterator);
1877         FLAC__ASSERT(0 != iterator->current);
1878         FLAC__ASSERT(0 != block);
1879
1880         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1881                 return false;
1882
1883         if(0 == iterator->current->prev) {
1884                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1885                 return false;
1886         }
1887
1888         if(0 == (node = node_new_()))
1889                 return false;
1890
1891         node->data = block;
1892         iterator_insert_node_(iterator, node);
1893         iterator->current = node;
1894         return true;
1895 }
1896
1897 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_after(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1898 {
1899         FLAC__Metadata_Node *node;
1900
1901         FLAC__ASSERT(0 != iterator);
1902         FLAC__ASSERT(0 != iterator->current);
1903         FLAC__ASSERT(0 != block);
1904
1905         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1906                 return false;
1907
1908         if(0 == (node = node_new_()))
1909                 return false;
1910
1911         node->data = block;
1912         iterator_insert_node_after_(iterator, node);
1913         iterator->current = node;
1914         return true;
1915 }
1916
1917
1918 /****************************************************************************
1919  *
1920  * Local function definitions
1921  *
1922  ***************************************************************************/
1923
1924 void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
1925 {
1926         unsigned i;
1927
1928         b += bytes;
1929
1930         for(i = 0; i < bytes; i++) {
1931                 *(--b) = (FLAC__byte)(val & 0xff);
1932                 val >>= 8;
1933         }
1934 }
1935
1936 void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
1937 {
1938         unsigned i;
1939
1940         for(i = 0; i < bytes; i++) {
1941                 *(b++) = (FLAC__byte)(val & 0xff);
1942                 val >>= 8;
1943         }
1944 }
1945
1946 void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes)
1947 {
1948         unsigned i;
1949
1950         b += bytes;
1951
1952         for(i = 0; i < bytes; i++) {
1953                 *(--b) = (FLAC__byte)(val & 0xff);
1954                 val >>= 8;
1955         }
1956 }
1957
1958 FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes)
1959 {
1960         FLAC__uint32 ret = 0;
1961         unsigned i;
1962
1963         for(i = 0; i < bytes; i++)
1964                 ret = (ret << 8) | (FLAC__uint32)(*b++);
1965
1966         return ret;
1967 }
1968
1969 FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes)
1970 {
1971         FLAC__uint32 ret = 0;
1972         unsigned i;
1973
1974         b += bytes;
1975
1976         for(i = 0; i < bytes; i++)
1977                 ret = (ret << 8) | (FLAC__uint32)(*--b);
1978
1979         return ret;
1980 }
1981
1982 FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes)
1983 {
1984         FLAC__uint64 ret = 0;
1985         unsigned i;
1986
1987         for(i = 0; i < bytes; i++)
1988                 ret = (ret << 8) | (FLAC__uint64)(*b++);
1989
1990         return ret;
1991 }
1992
1993 FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator)
1994 {
1995         FLAC__ASSERT(0 != iterator);
1996         FLAC__ASSERT(0 != iterator->file);
1997
1998         if(!read_metadata_block_header_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, &iterator->is_last, &iterator->type, &iterator->length)) {
1999                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2000                 return false;
2001         }
2002
2003         return true;
2004 }
2005
2006 FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block)
2007 {
2008         FLAC__ASSERT(0 != iterator);
2009         FLAC__ASSERT(0 != iterator->file);
2010
2011         iterator->status = read_metadata_block_data_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, block);
2012
2013         return (iterator->status == FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK);
2014 }
2015
2016 FLAC__bool read_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__bool *is_last, FLAC__MetadataType *type, unsigned *length)
2017 {
2018         FLAC__byte raw_header[FLAC__STREAM_METADATA_HEADER_LENGTH];
2019
2020         if(read_cb(raw_header, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
2021                 return false;
2022
2023         *is_last = raw_header[0] & 0x80? true : false;
2024         *type = (FLAC__MetadataType)(raw_header[0] & 0x7f);
2025         *length = unpack_uint32_(raw_header + 1, 3);
2026
2027         /* Note that we don't check:
2028          *    if(iterator->type >= FLAC__METADATA_TYPE_UNDEFINED)
2029          * we just will read in an opaque block
2030          */
2031
2032         return true;
2033 }
2034
2035 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata *block)
2036 {
2037         switch(block->type) {
2038                 case FLAC__METADATA_TYPE_STREAMINFO:
2039                         return read_metadata_block_data_streaminfo_cb_(handle, read_cb, &block->data.stream_info);
2040                 case FLAC__METADATA_TYPE_PADDING:
2041                         return read_metadata_block_data_padding_cb_(handle, seek_cb, &block->data.padding, block->length);
2042                 case FLAC__METADATA_TYPE_APPLICATION:
2043                         return read_metadata_block_data_application_cb_(handle, read_cb, &block->data.application, block->length);
2044                 case FLAC__METADATA_TYPE_SEEKTABLE:
2045                         return read_metadata_block_data_seektable_cb_(handle, read_cb, &block->data.seek_table, block->length);
2046                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
2047                         return read_metadata_block_data_vorbis_comment_cb_(handle, read_cb, &block->data.vorbis_comment);
2048                 case FLAC__METADATA_TYPE_CUESHEET:
2049                         return read_metadata_block_data_cuesheet_cb_(handle, read_cb, &block->data.cue_sheet);
2050                 case FLAC__METADATA_TYPE_PICTURE:
2051                         return read_metadata_block_data_picture_cb_(handle, read_cb, &block->data.picture);
2052                 default:
2053                         return read_metadata_block_data_unknown_cb_(handle, read_cb, &block->data.unknown, block->length);
2054         }
2055 }
2056
2057 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_StreamInfo *block)
2058 {
2059         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH], *b;
2060
2061         if(read_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
2062                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2063
2064         b = buffer;
2065
2066         /* we are using hardcoded numbers for simplicity but we should
2067          * probably eventually write a bit-level unpacker and use the
2068          * _STREAMINFO_ constants.
2069          */
2070         block->min_blocksize = unpack_uint32_(b, 2); b += 2;
2071         block->max_blocksize = unpack_uint32_(b, 2); b += 2;
2072         block->min_framesize = unpack_uint32_(b, 3); b += 3;
2073         block->max_framesize = unpack_uint32_(b, 3); b += 3;
2074         block->sample_rate = (unpack_uint32_(b, 2) << 4) | ((unsigned)(b[2] & 0xf0) >> 4);
2075         block->channels = (unsigned)((b[2] & 0x0e) >> 1) + 1;
2076         block->bits_per_sample = ((((unsigned)(b[2] & 0x01)) << 4) | (((unsigned)(b[3] & 0xf0)) >> 4)) + 1;
2077         block->total_samples = (((FLAC__uint64)(b[3] & 0x0f)) << 32) | unpack_uint64_(b+4, 4);
2078         memcpy(block->md5sum, b+8, 16);
2079
2080         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2081 }
2082
2083 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata_Padding *block, unsigned block_length)
2084 {
2085         (void)block; /* nothing to do; we don't care about reading the padding bytes */
2086
2087         if(0 != seek_cb(handle, block_length, SEEK_CUR))
2088                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2089
2090         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2091 }
2092
2093 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Application *block, unsigned block_length)
2094 {
2095         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
2096
2097         if(read_cb(block->id, 1, id_bytes, handle) != id_bytes)
2098                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2099
2100         block_length -= id_bytes;
2101
2102         if(block_length == 0) {
2103                 block->data = 0;
2104         }
2105         else {
2106                 if(0 == (block->data = (FLAC__byte*)malloc(block_length)))
2107                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2108
2109                 if(read_cb(block->data, 1, block_length, handle) != block_length)
2110                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2111         }
2112
2113         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2114 }
2115
2116 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_SeekTable *block, unsigned block_length)
2117 {
2118         unsigned i;
2119         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
2120
2121         FLAC__ASSERT(block_length % FLAC__STREAM_METADATA_SEEKPOINT_LENGTH == 0);
2122
2123         block->num_points = block_length / FLAC__STREAM_METADATA_SEEKPOINT_LENGTH;
2124
2125         if(block->num_points == 0)
2126                 block->points = 0;
2127         else if(0 == (block->points = (FLAC__StreamMetadata_SeekPoint*)malloc(block->num_points * sizeof(FLAC__StreamMetadata_SeekPoint))))
2128                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2129
2130         for(i = 0; i < block->num_points; i++) {
2131                 if(read_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
2132                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2133                 /* some MAGIC NUMBERs here */
2134                 block->points[i].sample_number = unpack_uint64_(buffer, 8);
2135                 block->points[i].stream_offset = unpack_uint64_(buffer+8, 8);
2136                 block->points[i].frame_samples = unpack_uint32_(buffer+16, 2);
2137         }
2138
2139         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2140 }
2141
2142 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_entry_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment_Entry *entry)
2143 {
2144         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
2145         FLAC__byte buffer[4]; /* magic number is asserted below */
2146
2147         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8 == sizeof(buffer));
2148
2149         if(read_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2150                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2151         entry->length = unpack_uint32_little_endian_(buffer, entry_length_len);
2152
2153         if(0 != entry->entry)
2154                 free(entry->entry);
2155
2156         if(entry->length == 0) {
2157                 entry->entry = 0;
2158         }
2159         else {
2160                 if(0 == (entry->entry = (FLAC__byte*)malloc(entry->length+1)))
2161                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2162
2163                 if(read_cb(entry->entry, 1, entry->length, handle) != entry->length)
2164                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2165
2166                 entry->entry[entry->length] = '\0';
2167         }
2168
2169         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2170 }
2171
2172 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment *block)
2173 {
2174         unsigned i;
2175         FLAC__Metadata_SimpleIteratorStatus status;
2176         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2177         FLAC__byte buffer[4]; /* magic number is asserted below */
2178
2179         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8 == sizeof(buffer));
2180
2181         if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, &(block->vendor_string))))
2182                 return status;
2183
2184         if(read_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2185                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2186         block->num_comments = unpack_uint32_little_endian_(buffer, num_comments_len);
2187
2188         if(block->num_comments == 0) {
2189                 block->comments = 0;
2190         }
2191         else if(0 == (block->comments = (FLAC__StreamMetadata_VorbisComment_Entry*)calloc(block->num_comments, sizeof(FLAC__StreamMetadata_VorbisComment_Entry))))
2192                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2193
2194         for(i = 0; i < block->num_comments; i++) {
2195                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, block->comments + i)))
2196                         return status;
2197         }
2198
2199         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2200 }
2201
2202 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet_Track *track)
2203 {
2204         unsigned i, len;
2205         FLAC__byte buffer[32]; /* asserted below that this is big enough */
2206
2207         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2208         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2209         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);
2210
2211         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2212         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2213         if(read_cb(buffer, 1, len, handle) != len)
2214                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2215         track->offset = unpack_uint64_(buffer, len);
2216
2217         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2218         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2219         if(read_cb(buffer, 1, len, handle) != len)
2220                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2221         track->number = (FLAC__byte)unpack_uint32_(buffer, len);
2222
2223         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2224         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2225         if(read_cb(track->isrc, 1, len, handle) != len)
2226                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2227
2228         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);
2229         len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2230         if(read_cb(buffer, 1, len, handle) != len)
2231                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2232         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN == 1);
2233         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN == 1);
2234         track->type = buffer[0] >> 7;
2235         track->pre_emphasis = (buffer[0] >> 6) & 1;
2236
2237         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2238         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2239         if(read_cb(buffer, 1, len, handle) != len)
2240                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2241         track->num_indices = (FLAC__byte)unpack_uint32_(buffer, len);
2242
2243         if(track->num_indices == 0) {
2244                 track->indices = 0;
2245         }
2246         else if(0 == (track->indices = (FLAC__StreamMetadata_CueSheet_Index*)calloc(track->num_indices, sizeof(FLAC__StreamMetadata_CueSheet_Index))))
2247                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2248
2249         for(i = 0; i < track->num_indices; i++) {
2250                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2251                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2252                 if(read_cb(buffer, 1, len, handle) != len)
2253                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2254                 track->indices[i].offset = unpack_uint64_(buffer, len);
2255
2256                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2257                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2258                 if(read_cb(buffer, 1, len, handle) != len)
2259                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2260                 track->indices[i].number = (FLAC__byte)unpack_uint32_(buffer, len);
2261
2262                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2263                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2264                 if(read_cb(buffer, 1, len, handle) != len)
2265                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2266         }
2267
2268         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2269 }
2270
2271 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet *block)
2272 {
2273         unsigned i, len;
2274         FLAC__Metadata_SimpleIteratorStatus status;
2275         FLAC__byte buffer[1024]; /* MSVC needs a constant expression so we put a magic number and assert */
2276
2277         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN)/8 <= sizeof(buffer));
2278         FLAC__ASSERT(sizeof(FLAC__uint64) <= sizeof(buffer));
2279
2280         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2281         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2282         if(read_cb(block->media_catalog_number, 1, len, handle) != len)
2283                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2284
2285         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2286         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2287         if(read_cb(buffer, 1, len, handle) != len)
2288                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2289         block->lead_in = unpack_uint64_(buffer, len);
2290
2291         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2292         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2293         if(read_cb(buffer, 1, len, handle) != len)
2294                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2295         block->is_cd = buffer[0]&0x80? true : false;
2296
2297         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2298         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2299         if(read_cb(buffer, 1, len, handle) != len)
2300                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2301         block->num_tracks = unpack_uint32_(buffer, len);
2302
2303         if(block->num_tracks == 0) {
2304                 block->tracks = 0;
2305         }
2306         else if(0 == (block->tracks = (FLAC__StreamMetadata_CueSheet_Track*)calloc(block->num_tracks, sizeof(FLAC__StreamMetadata_CueSheet_Track))))
2307                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2308
2309         for(i = 0; i < block->num_tracks; i++) {
2310                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_cuesheet_track_cb_(handle, read_cb, block->tracks + i)))
2311                         return status;
2312         }
2313
2314         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2315 }
2316
2317 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)
2318 {
2319         FLAC__byte buffer[sizeof(FLAC__uint32)];
2320
2321         FLAC__ASSERT(0 != data);
2322         FLAC__ASSERT(length_len%8 == 0);
2323
2324         length_len /= 8; /* convert to bytes */
2325
2326         FLAC__ASSERT(sizeof(buffer) >= length_len);
2327
2328         if(read_cb(buffer, 1, length_len, handle) != length_len)
2329                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2330         *length = unpack_uint32_(buffer, length_len);
2331
2332         if(0 != *data)
2333                 free(*data);
2334
2335         if(0 == (*data = (FLAC__byte*)malloc(*length+1)))
2336                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2337
2338         if(*length > 0) {
2339                 if(read_cb(*data, 1, *length, handle) != *length)
2340                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2341         }
2342
2343         (*data)[*length] = '\0';
2344
2345         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2346 }
2347
2348 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Picture *block)
2349 {
2350         FLAC__Metadata_SimpleIteratorStatus status;
2351         FLAC__byte buffer[4]; /* asserted below that this is big enough */
2352         FLAC__uint32 len;
2353
2354         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8);
2355         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8);
2356         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8);
2357         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8);
2358         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8);
2359
2360         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_TYPE_LEN % 8 == 0);
2361         len = FLAC__STREAM_METADATA_PICTURE_TYPE_LEN / 8;
2362         if(read_cb(buffer, 1, len, handle) != len)
2363                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2364         block->type = (FLAC__StreamMetadata_Picture_Type)unpack_uint32_(buffer, len);
2365
2366         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)
2367                 return status;
2368
2369         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)
2370                 return status;
2371
2372         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN % 8 == 0);
2373         len = FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN / 8;
2374         if(read_cb(buffer, 1, len, handle) != len)
2375                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2376         block->width = unpack_uint32_(buffer, len);
2377
2378         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN % 8 == 0);
2379         len = FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN / 8;
2380         if(read_cb(buffer, 1, len, handle) != len)
2381                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2382         block->height = unpack_uint32_(buffer, len);
2383
2384         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN % 8 == 0);
2385         len = FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN / 8;
2386         if(read_cb(buffer, 1, len, handle) != len)
2387                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2388         block->depth = unpack_uint32_(buffer, len);
2389
2390         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_COLORS_LEN % 8 == 0);
2391         len = FLAC__STREAM_METADATA_PICTURE_COLORS_LEN / 8;
2392         if(read_cb(buffer, 1, len, handle) != len)
2393                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2394         block->colors = unpack_uint32_(buffer, len);
2395
2396         /* for convenience we use read_metadata_block_data_picture_cstring_cb_() even though it adds an extra terminating NUL we don't use */
2397         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)
2398                 return status;
2399
2400         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2401 }
2402
2403 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2404 {
2405         if(block_length == 0) {
2406                 block->data = 0;
2407         }
2408         else {
2409                 if(0 == (block->data = (FLAC__byte*)malloc(block_length)))
2410                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2411
2412                 if(read_cb(block->data, 1, block_length, handle) != block_length)
2413                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2414         }
2415
2416         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2417 }
2418
2419 FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2420 {
2421         FLAC__ASSERT(0 != file);
2422         FLAC__ASSERT(0 != status);
2423
2424         if(!write_metadata_block_header_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2425                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2426                 return false;
2427         }
2428
2429         return true;
2430 }
2431
2432 FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2433 {
2434         FLAC__ASSERT(0 != file);
2435         FLAC__ASSERT(0 != status);
2436
2437         if (write_metadata_block_data_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2438                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2439                 return true;
2440         }
2441         else {
2442                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2443                 return false;
2444         }
2445 }
2446
2447 FLAC__bool write_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2448 {
2449         FLAC__byte buffer[FLAC__STREAM_METADATA_HEADER_LENGTH];
2450
2451         FLAC__ASSERT(block->length < (1u << FLAC__STREAM_METADATA_LENGTH_LEN));
2452
2453         buffer[0] = (block->is_last? 0x80 : 0) | (FLAC__byte)block->type;
2454         pack_uint32_(block->length, buffer + 1, 3);
2455
2456         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
2457                 return false;
2458
2459         return true;
2460 }
2461
2462 FLAC__bool write_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2463 {
2464         FLAC__ASSERT(0 != block);
2465
2466         switch(block->type) {
2467                 case FLAC__METADATA_TYPE_STREAMINFO:
2468                         return write_metadata_block_data_streaminfo_cb_(handle, write_cb, &block->data.stream_info);
2469                 case FLAC__METADATA_TYPE_PADDING:
2470                         return write_metadata_block_data_padding_cb_(handle, write_cb, &block->data.padding, block->length);
2471                 case FLAC__METADATA_TYPE_APPLICATION:
2472                         return write_metadata_block_data_application_cb_(handle, write_cb, &block->data.application, block->length);
2473                 case FLAC__METADATA_TYPE_SEEKTABLE:
2474                         return write_metadata_block_data_seektable_cb_(handle, write_cb, &block->data.seek_table);
2475                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
2476                         return write_metadata_block_data_vorbis_comment_cb_(handle, write_cb, &block->data.vorbis_comment);
2477                 case FLAC__METADATA_TYPE_CUESHEET:
2478                         return write_metadata_block_data_cuesheet_cb_(handle, write_cb, &block->data.cue_sheet);
2479                 case FLAC__METADATA_TYPE_PICTURE:
2480                         return write_metadata_block_data_picture_cb_(handle, write_cb, &block->data.picture);
2481                 default:
2482                         return write_metadata_block_data_unknown_cb_(handle, write_cb, &block->data.unknown, block->length);
2483         }
2484 }
2485
2486 FLAC__bool write_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_StreamInfo *block)
2487 {
2488         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH];
2489         const unsigned channels1 = block->channels - 1;
2490         const unsigned bps1 = block->bits_per_sample - 1;
2491
2492         /* we are using hardcoded numbers for simplicity but we should
2493          * probably eventually write a bit-level packer and use the
2494          * _STREAMINFO_ constants.
2495          */
2496         pack_uint32_(block->min_blocksize, buffer, 2);
2497         pack_uint32_(block->max_blocksize, buffer+2, 2);
2498         pack_uint32_(block->min_framesize, buffer+4, 3);
2499         pack_uint32_(block->max_framesize, buffer+7, 3);
2500         buffer[10] = (block->sample_rate >> 12) & 0xff;
2501         buffer[11] = (block->sample_rate >> 4) & 0xff;
2502         buffer[12] = ((block->sample_rate & 0x0f) << 4) | (channels1 << 1) | (bps1 >> 4);
2503         buffer[13] = (FLAC__byte)(((bps1 & 0x0f) << 4) | ((block->total_samples >> 32) & 0x0f));
2504         pack_uint32_((FLAC__uint32)block->total_samples, buffer+14, 4);
2505         memcpy(buffer+18, block->md5sum, 16);
2506
2507         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
2508                 return false;
2509
2510         return true;
2511 }
2512
2513 FLAC__bool write_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Padding *block, unsigned block_length)
2514 {
2515         unsigned i, n = block_length;
2516         FLAC__byte buffer[1024];
2517
2518         (void)block;
2519
2520         memset(buffer, 0, 1024);
2521
2522         for(i = 0; i < n/1024; i++)
2523                 if(write_cb(buffer, 1, 1024, handle) != 1024)
2524                         return false;
2525
2526         n %= 1024;
2527
2528         if(write_cb(buffer, 1, n, handle) != n)
2529                 return false;
2530
2531         return true;
2532 }
2533
2534 FLAC__bool write_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Application *block, unsigned block_length)
2535 {
2536         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
2537
2538         if(write_cb(block->id, 1, id_bytes, handle) != id_bytes)
2539                 return false;
2540
2541         block_length -= id_bytes;
2542
2543         if(write_cb(block->data, 1, block_length, handle) != block_length)
2544                 return false;
2545
2546         return true;
2547 }
2548
2549 FLAC__bool write_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_SeekTable *block)
2550 {
2551         unsigned i;
2552         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
2553
2554         for(i = 0; i < block->num_points; i++) {
2555                 /* some MAGIC NUMBERs here */
2556                 pack_uint64_(block->points[i].sample_number, buffer, 8);
2557                 pack_uint64_(block->points[i].stream_offset, buffer+8, 8);
2558                 pack_uint32_(block->points[i].frame_samples, buffer+16, 2);
2559                 if(write_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
2560                         return false;
2561         }
2562
2563         return true;
2564 }
2565
2566 FLAC__bool write_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_VorbisComment *block)
2567 {
2568         unsigned i;
2569         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
2570         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2571         FLAC__byte buffer[4]; /* magic number is asserted below */
2572
2573         FLAC__ASSERT(max(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN, FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN) / 8 == sizeof(buffer));
2574
2575         pack_uint32_little_endian_(block->vendor_string.length, buffer, entry_length_len);
2576         if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2577                 return false;
2578         if(write_cb(block->vendor_string.entry, 1, block->vendor_string.length, handle) != block->vendor_string.length)
2579                 return false;
2580
2581         pack_uint32_little_endian_(block->num_comments, buffer, num_comments_len);
2582         if(write_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2583                 return false;
2584
2585         for(i = 0; i < block->num_comments; i++) {
2586                 pack_uint32_little_endian_(block->comments[i].length, buffer, entry_length_len);
2587                 if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2588                         return false;
2589                 if(write_cb(block->comments[i].entry, 1, block->comments[i].length, handle) != block->comments[i].length)
2590                         return false;
2591         }
2592
2593         return true;
2594 }
2595
2596 FLAC__bool write_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_CueSheet *block)
2597 {
2598         unsigned i, j, len;
2599         FLAC__byte buffer[1024]; /* asserted below that this is big enough */
2600
2601         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2602         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN/8);
2603         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);
2604         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2605
2606         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2607         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2608         if(write_cb(block->media_catalog_number, 1, len, handle) != len)
2609                 return false;
2610
2611         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2612         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2613         pack_uint64_(block->lead_in, buffer, len);
2614         if(write_cb(buffer, 1, len, handle) != len)
2615                 return false;
2616
2617         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2618         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2619         memset(buffer, 0, len);
2620         if(block->is_cd)
2621                 buffer[0] |= 0x80;
2622         if(write_cb(buffer, 1, len, handle) != len)
2623                 return false;
2624
2625         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2626         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2627         pack_uint32_(block->num_tracks, buffer, len);
2628         if(write_cb(buffer, 1, len, handle) != len)
2629                 return false;
2630
2631         for(i = 0; i < block->num_tracks; i++) {
2632                 FLAC__StreamMetadata_CueSheet_Track *track = block->tracks + i;
2633
2634                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2635                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2636                 pack_uint64_(track->offset, buffer, len);
2637                 if(write_cb(buffer, 1, len, handle) != len)
2638                         return false;
2639
2640                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2641                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2642                 pack_uint32_(track->number, buffer, len);
2643                 if(write_cb(buffer, 1, len, handle) != len)
2644                         return false;
2645
2646                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2647                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2648                 if(write_cb(track->isrc, 1, len, handle) != len)
2649                         return false;
2650
2651                 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);
2652                 len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2653                 memset(buffer, 0, len);
2654                 buffer[0] = (track->type << 7) | (track->pre_emphasis << 6);
2655                 if(write_cb(buffer, 1, len, handle) != len)
2656                         return false;
2657
2658                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2659                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2660                 pack_uint32_(track->num_indices, buffer, len);
2661                 if(write_cb(buffer, 1, len, handle) != len)
2662                         return false;
2663
2664                 for(j = 0; j < track->num_indices; j++) {
2665                         FLAC__StreamMetadata_CueSheet_Index *index = track->indices + j;
2666
2667                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2668                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2669                         pack_uint64_(index->offset, buffer, len);
2670                         if(write_cb(buffer, 1, len, handle) != len)
2671                                 return false;
2672
2673                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2674                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2675                         pack_uint32_(index->number, buffer, len);
2676                         if(write_cb(buffer, 1, len, handle) != len)
2677                                 return false;
2678
2679                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2680                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2681                         memset(buffer, 0, len);
2682                         if(write_cb(buffer, 1, len, handle) != len)
2683                                 return false;
2684                 }
2685         }
2686
2687         return true;
2688 }
2689
2690 FLAC__bool write_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Picture *block)
2691 {
2692         unsigned len;
2693         size_t slen;
2694         FLAC__byte buffer[4]; /* magic number is asserted below */
2695
2696         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_TYPE_LEN%8);
2697         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN%8);
2698         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN%8);
2699         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN%8);
2700         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN%8);
2701         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN%8);
2702         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_COLORS_LEN%8);
2703         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN%8);
2704         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8);
2705         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN/8);
2706         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN/8);
2707         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8);
2708         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8);
2709         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8);
2710         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8);
2711         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN/8);
2712
2713         len = FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8;
2714         pack_uint32_(block->type, buffer, len);
2715         if(write_cb(buffer, 1, len, handle) != len)
2716                 return false;
2717
2718         len = FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN/8;
2719         slen = strlen(block->mime_type);
2720         pack_uint32_(slen, buffer, len);
2721         if(write_cb(buffer, 1, len, handle) != len)
2722                 return false;
2723         if(write_cb(block->mime_type, 1, slen, handle) != slen)
2724                 return false;
2725
2726         len = FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN/8;
2727         slen = strlen((const char *)block->description);
2728         pack_uint32_(slen, buffer, len);
2729         if(write_cb(buffer, 1, len, handle) != len)
2730                 return false;
2731         if(write_cb(block->description, 1, slen, handle) != slen)
2732                 return false;
2733
2734         len = FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8;
2735         pack_uint32_(block->width, buffer, len);
2736         if(write_cb(buffer, 1, len, handle) != len)
2737                 return false;
2738
2739         len = FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8;
2740         pack_uint32_(block->height, buffer, len);
2741         if(write_cb(buffer, 1, len, handle) != len)
2742                 return false;
2743
2744         len = FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8;
2745         pack_uint32_(block->depth, buffer, len);
2746         if(write_cb(buffer, 1, len, handle) != len)
2747                 return false;
2748
2749         len = FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8;
2750         pack_uint32_(block->colors, buffer, len);
2751         if(write_cb(buffer, 1, len, handle) != len)
2752                 return false;
2753
2754         len = FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN/8;
2755         pack_uint32_(block->data_length, buffer, len);
2756         if(write_cb(buffer, 1, len, handle) != len)
2757                 return false;
2758         if(write_cb(block->data, 1, block->data_length, handle) != block->data_length)
2759                 return false;
2760
2761         return true;
2762 }
2763
2764 FLAC__bool write_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2765 {
2766         if(write_cb(block->data, 1, block_length, handle) != block_length)
2767                 return false;
2768
2769         return true;
2770 }
2771
2772 FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block)
2773 {
2774         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2775                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2776                 return false;
2777         }
2778
2779         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2780                 return false;
2781
2782         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2783                 return false;
2784
2785         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2786                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2787                 return false;
2788         }
2789
2790         return read_metadata_block_header_(iterator);
2791 }
2792
2793 FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last)
2794 {
2795         FLAC__StreamMetadata *padding;
2796
2797         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2798                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2799                 return false;
2800         }
2801
2802         block->is_last = false;
2803
2804         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2805                 return false;
2806
2807         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2808                 return false;
2809
2810         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING)))
2811                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2812
2813         padding->is_last = padding_is_last;
2814         padding->length = padding_length;
2815
2816         if(!write_metadata_block_header_(iterator->file, &iterator->status, padding)) {
2817                 FLAC__metadata_object_delete(padding);
2818                 return false;
2819         }
2820
2821         if(!write_metadata_block_data_(iterator->file, &iterator->status, padding)) {
2822                 FLAC__metadata_object_delete(padding);
2823                 return false;
2824         }
2825
2826         FLAC__metadata_object_delete(padding);
2827
2828         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2829                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2830                 return false;
2831         }
2832
2833         return read_metadata_block_header_(iterator);
2834 }
2835
2836 FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append)
2837 {
2838         FILE *tempfile;
2839         char *tempfilename;
2840         int fixup_is_last_code = 0; /* 0 => no need to change any is_last flags */
2841         off_t fixup_is_last_flag_offset = -1;
2842
2843         FLAC__ASSERT(0 != block || append == false);
2844
2845         if(iterator->is_last) {
2846                 if(append) {
2847                         fixup_is_last_code = 1; /* 1 => clear the is_last flag at the following offset */
2848                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2849                 }
2850                 else if(0 == block) {
2851                         simple_iterator_push_(iterator);
2852                         if(!FLAC__metadata_simple_iterator_prev(iterator)) {
2853                                 (void)simple_iterator_pop_(iterator);
2854                                 return false;
2855                         }
2856                         fixup_is_last_code = -1; /* -1 => set the is_last the flag at the following offset */
2857                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2858                         if(!simple_iterator_pop_(iterator))
2859                                 return false;
2860                 }
2861         }
2862
2863         if(!simple_iterator_copy_file_prefix_(iterator, &tempfile, &tempfilename, append))
2864                 return false;
2865
2866         if(0 != block) {
2867                 if(!write_metadata_block_header_(tempfile, &iterator->status, block)) {
2868                         cleanup_tempfile_(&tempfile, &tempfilename);
2869                         return false;
2870                 }
2871
2872                 if(!write_metadata_block_data_(tempfile, &iterator->status, block)) {
2873                         cleanup_tempfile_(&tempfile, &tempfilename);
2874                         return false;
2875                 }
2876         }
2877
2878         if(!simple_iterator_copy_file_postfix_(iterator, &tempfile, &tempfilename, fixup_is_last_code, fixup_is_last_flag_offset, block==0))
2879                 return false;
2880
2881         if(append)
2882                 return FLAC__metadata_simple_iterator_next(iterator);
2883
2884         return true;
2885 }
2886
2887 void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator)
2888 {
2889         FLAC__ASSERT(iterator->depth+1 < SIMPLE_ITERATOR_MAX_PUSH_DEPTH);
2890         iterator->offset[iterator->depth+1] = iterator->offset[iterator->depth];
2891         iterator->depth++;
2892 }
2893
2894 FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator)
2895 {
2896         FLAC__ASSERT(iterator->depth > 0);
2897         iterator->depth--;
2898         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2899                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2900                 return false;
2901         }
2902
2903         return read_metadata_block_header_(iterator);
2904 }
2905
2906 /* return meanings:
2907  * 0: ok
2908  * 1: read error
2909  * 2: seek error
2910  * 3: not a FLAC file
2911  */
2912 unsigned seek_to_first_metadata_block_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb)
2913 {
2914         FLAC__byte buffer[4];
2915         size_t n;
2916         unsigned i;
2917
2918         FLAC__ASSERT(FLAC__STREAM_SYNC_LENGTH == sizeof(buffer));
2919
2920         /* skip any id3v2 tag */
2921         errno = 0;
2922         n = read_cb(buffer, 1, 4, handle);
2923         if(errno)
2924                 return 1;
2925         else if(n != 4)
2926                 return 3;
2927         else if(0 == memcmp(buffer, "ID3", 3)) {
2928                 unsigned tag_length = 0;
2929
2930                 /* skip to the tag length */
2931                 if(seek_cb(handle, 2, SEEK_CUR) < 0)
2932                         return 2;
2933
2934                 /* read the length */
2935                 for(i = 0; i < 4; i++) {
2936                         if(read_cb(buffer, 1, 1, handle) < 1 || buffer[0] & 0x80)
2937                                 return 1;
2938                         tag_length <<= 7;
2939                         tag_length |= (buffer[0] & 0x7f);
2940                 }
2941
2942                 /* skip the rest of the tag */
2943                 if(seek_cb(handle, tag_length, SEEK_CUR) < 0)
2944                         return 2;
2945
2946                 /* read the stream sync code */
2947                 errno = 0;
2948                 n = read_cb(buffer, 1, 4, handle);
2949                 if(errno)
2950                         return 1;
2951                 else if(n != 4)
2952                         return 3;
2953         }
2954
2955         /* check for the fLaC signature */
2956         if(0 == memcmp(FLAC__STREAM_SYNC_STRING, buffer, FLAC__STREAM_SYNC_LENGTH))
2957                 return 0;
2958         else
2959                 return 3;
2960 }
2961
2962 unsigned seek_to_first_metadata_block_(FILE *f)
2963 {
2964         return seek_to_first_metadata_block_cb_((FLAC__IOHandle)f, (FLAC__IOCallback_Read)fread, fseek_wrapper_);
2965 }
2966
2967 FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append)
2968 {
2969         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];
2970
2971         if(0 != fseeko(iterator->file, 0, SEEK_SET)) {
2972                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2973                 return false;
2974         }
2975         if(!open_tempfile_(iterator->filename, iterator->tempfile_path_prefix, tempfile, tempfilename, &iterator->status)) {
2976                 cleanup_tempfile_(tempfile, tempfilename);
2977                 return false;
2978         }
2979         if(!copy_n_bytes_from_file_(iterator->file, *tempfile, offset_end, &iterator->status)) {
2980                 cleanup_tempfile_(tempfile, tempfilename);
2981                 return false;
2982         }
2983
2984         return true;
2985 }
2986
2987 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)
2988 {
2989         off_t save_offset = iterator->offset[iterator->depth];
2990         FLAC__ASSERT(0 != *tempfile);
2991
2992         if(0 != fseeko(iterator->file, save_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length, SEEK_SET)) {
2993                 cleanup_tempfile_(tempfile, tempfilename);
2994                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2995                 return false;
2996         }
2997         if(!copy_remaining_bytes_from_file_(iterator->file, *tempfile, &iterator->status)) {
2998                 cleanup_tempfile_(tempfile, tempfilename);
2999                 return false;
3000         }
3001
3002         if(fixup_is_last_code != 0) {
3003                 /*
3004                  * if code == 1, it means a block was appended to the end so
3005                  *   we have to clear the is_last flag of the previous block
3006                  * if code == -1, it means the last block was deleted so
3007                  *   we have to set the is_last flag of the previous block
3008                  */
3009                 /* MAGIC NUMBERs here; we know the is_last flag is the high bit of the byte at this location */
3010                 FLAC__byte x;
3011                 if(0 != fseeko(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
3012                         cleanup_tempfile_(tempfile, tempfilename);
3013                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3014                         return false;
3015                 }
3016                 if(fread(&x, 1, 1, *tempfile) != 1) {
3017                         cleanup_tempfile_(tempfile, tempfilename);
3018                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3019                         return false;
3020                 }
3021                 if(fixup_is_last_code > 0) {
3022                         FLAC__ASSERT(x & 0x80);
3023                         x &= 0x7f;
3024                 }
3025                 else {
3026                         FLAC__ASSERT(!(x & 0x80));
3027                         x |= 0x80;
3028                 }
3029                 if(0 != fseeko(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
3030                         cleanup_tempfile_(tempfile, tempfilename);
3031                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3032                         return false;
3033                 }
3034                 if(local__fwrite(&x, 1, 1, *tempfile) != 1) {
3035                         cleanup_tempfile_(tempfile, tempfilename);
3036                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3037                         return false;
3038                 }
3039         }
3040
3041         (void)fclose(iterator->file);
3042
3043         if(!transport_tempfile_(iterator->filename, tempfile, tempfilename, &iterator->status))
3044                 return false;
3045
3046         if(iterator->has_stats)
3047                 set_file_stats_(iterator->filename, &iterator->stats);
3048
3049         if(!simple_iterator_prime_input_(iterator, !iterator->is_writable))
3050                 return false;
3051         if(backup) {
3052                 while(iterator->offset[iterator->depth] + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length < save_offset)
3053                         if(!FLAC__metadata_simple_iterator_next(iterator))
3054                                 return false;
3055                 return true;
3056         }
3057         else {
3058                 /* move the iterator to it's original block faster by faking a push, then doing a pop_ */
3059                 FLAC__ASSERT(iterator->depth == 0);
3060                 iterator->offset[0] = save_offset;
3061                 iterator->depth++;
3062                 return simple_iterator_pop_(iterator);
3063         }
3064 }
3065
3066 FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status)
3067 {
3068         FLAC__byte buffer[8192];
3069         size_t n;
3070
3071         FLAC__ASSERT(bytes >= 0);
3072         while(bytes > 0) {
3073                 n = min(sizeof(buffer), (size_t)bytes);
3074                 if(fread(buffer, 1, n, file) != n) {
3075                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3076                         return false;
3077                 }
3078                 if(local__fwrite(buffer, 1, n, tempfile) != n) {
3079                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3080                         return false;
3081                 }
3082                 bytes -= n;
3083         }
3084
3085         return true;
3086 }
3087
3088 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)
3089 {
3090         FLAC__byte buffer[8192];
3091         size_t n;
3092
3093         FLAC__ASSERT(bytes >= 0);
3094         while(bytes > 0) {
3095                 n = min(sizeof(buffer), (size_t)bytes);
3096                 if(read_cb(buffer, 1, n, handle) != n) {
3097                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3098                         return false;
3099                 }
3100                 if(temp_write_cb(buffer, 1, n, temp_handle) != n) {
3101                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3102                         return false;
3103                 }
3104                 bytes -= n;
3105         }
3106
3107         return true;
3108 }
3109
3110 FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status)
3111 {
3112         FLAC__byte buffer[8192];
3113         size_t n;
3114
3115         while(!feof(file)) {
3116                 n = fread(buffer, 1, sizeof(buffer), file);
3117                 if(n == 0 && !feof(file)) {
3118                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3119                         return false;
3120                 }
3121                 if(n > 0 && local__fwrite(buffer, 1, n, tempfile) != n) {
3122                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3123                         return false;
3124                 }
3125         }
3126
3127         return true;
3128 }
3129
3130 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)
3131 {
3132         FLAC__byte buffer[8192];
3133         size_t n;
3134
3135         while(!eof_cb(handle)) {
3136                 n = read_cb(buffer, 1, sizeof(buffer), handle);
3137                 if(n == 0 && !eof_cb(handle)) {
3138                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3139                         return false;
3140                 }
3141                 if(n > 0 && temp_write_cb(buffer, 1, n, temp_handle) != n) {
3142                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3143                         return false;
3144                 }
3145         }
3146
3147         return true;
3148 }
3149
3150 FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
3151 {
3152         static const char *tempfile_suffix = ".metadata_edit";
3153         if(0 == tempfile_path_prefix) {
3154                 if(0 == (*tempfilename = (char*)malloc(strlen(filename) + strlen(tempfile_suffix) + 1))) {
3155                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
3156                         return false;
3157                 }
3158                 strcpy(*tempfilename, filename);
3159                 strcat(*tempfilename, tempfile_suffix);
3160         }
3161         else {
3162                 const char *p = strrchr(filename, '/');
3163                 if(0 == p)
3164                         p = filename;
3165                 else
3166                         p++;
3167
3168                 if(0 == (*tempfilename = (char*)malloc(strlen(tempfile_path_prefix) + 1 + strlen(p) + strlen(tempfile_suffix) + 1))) {
3169                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
3170                         return false;
3171                 }
3172                 strcpy(*tempfilename, tempfile_path_prefix);
3173                 strcat(*tempfilename, "/");
3174                 strcat(*tempfilename, p);
3175                 strcat(*tempfilename, tempfile_suffix);
3176         }
3177
3178         if(0 == (*tempfile = fopen(*tempfilename, "w+b"))) {
3179                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
3180                 return false;
3181         }
3182
3183         return true;
3184 }
3185
3186 FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
3187 {
3188         FLAC__ASSERT(0 != filename);
3189         FLAC__ASSERT(0 != tempfile);
3190         FLAC__ASSERT(0 != *tempfile);
3191         FLAC__ASSERT(0 != tempfilename);
3192         FLAC__ASSERT(0 != *tempfilename);
3193         FLAC__ASSERT(0 != status);
3194
3195         (void)fclose(*tempfile);
3196         *tempfile = 0;
3197
3198 #if defined _MSC_VER || defined __BORLANDC__ || defined __MINGW32__ || defined __EMX__
3199         /* on some flavors of windows, rename() will fail if the destination already exists */
3200         if(unlink(filename) < 0) {
3201                 cleanup_tempfile_(tempfile, tempfilename);
3202                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR;
3203                 return false;
3204         }
3205 #endif
3206
3207         /*@@@ to fully support the tempfile_path_prefix we need to update this piece to actually copy across filesystems instead of just rename(): */
3208         if(0 != rename(*tempfilename, filename)) {
3209                 cleanup_tempfile_(tempfile, tempfilename);
3210                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR;
3211                 return false;
3212         }
3213
3214         cleanup_tempfile_(tempfile, tempfilename);
3215
3216         return true;
3217 }
3218
3219 void cleanup_tempfile_(FILE **tempfile, char **tempfilename)
3220 {
3221         if(0 != *tempfile) {
3222                 (void)fclose(*tempfile);
3223                 *tempfile = 0;
3224         }
3225
3226         if(0 != *tempfilename) {
3227                 (void)unlink(*tempfilename);
3228                 free(*tempfilename);
3229                 *tempfilename = 0;
3230         }
3231 }
3232
3233 FLAC__bool get_file_stats_(const char *filename, struct stat *stats)
3234 {
3235         FLAC__ASSERT(0 != filename);
3236         FLAC__ASSERT(0 != stats);
3237         return (0 == stat(filename, stats));
3238 }
3239
3240 void set_file_stats_(const char *filename, struct stat *stats)
3241 {
3242         struct utimbuf srctime;
3243
3244         FLAC__ASSERT(0 != filename);
3245         FLAC__ASSERT(0 != stats);
3246
3247         srctime.actime = stats->st_atime;
3248         srctime.modtime = stats->st_mtime;
3249         (void)chmod(filename, stats->st_mode);
3250         (void)utime(filename, &srctime);
3251 #if !defined _MSC_VER && !defined __BORLANDC__ && !defined __MINGW32__ && !defined __EMX__
3252         (void)chown(filename, stats->st_uid, -1);
3253         (void)chown(filename, -1, stats->st_gid);
3254 #endif
3255 }
3256
3257 int fseek_wrapper_(FLAC__IOHandle handle, FLAC__int64 offset, int whence)
3258 {
3259         return fseeko((FILE*)handle, (off_t)offset, whence);
3260 }
3261
3262 FLAC__int64 ftell_wrapper_(FLAC__IOHandle handle)
3263 {
3264         return ftello((FILE*)handle);
3265 }
3266
3267 FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status)
3268 {
3269         switch(status) {
3270                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK:
3271                         return FLAC__METADATA_CHAIN_STATUS_OK;
3272                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT:
3273                         return FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT;
3274                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE:
3275                         return FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
3276                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE:
3277                         return FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE;
3278                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE:
3279                         return FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE;
3280                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA:
3281                         return FLAC__METADATA_CHAIN_STATUS_BAD_METADATA;
3282                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR:
3283                         return FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
3284                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR:
3285                         return FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
3286                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR:
3287                         return FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
3288                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR:
3289                         return FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR;
3290                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR:
3291                         return FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR;
3292                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR:
3293                         return FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
3294                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR:
3295                 default:
3296                         return FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
3297         }
3298 }