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 __BORLANDC__ || defined __MINGW32__
  42 #if defined __BORLANDC__
  43 #include <utime.h> /* for utime() */
  44 #else
  45 #include <sys/utime.h> /* for utime() */
  46 #endif
  47 #include <io.h> /* for chmod() */
  48 #include <sys/types.h> /* for off_t */
  49 #if _MSC_VER <= 1200 || defined __BORLANDC__ /* @@@ [2G limit] */
  50 #define fseeko fseek
  51 #define ftello ftell
  52 #endif
  53 #else
  54 #include <sys/types.h> /* some flavors of BSD (like OS X) require this to get time_t */
  55 #include <utime.h> /* for utime() */
  56 #include <unistd.h> /* for chown(), unlink() */
  57 #endif
  58 #include <sys/stat.h> /* for stat(), maybe chmod() */
  59
  60 #include "private/metadata.h"
  61
  62 #include "FLAC/assert.h"
  63 #include "FLAC/stream_decoder.h"
  64
  65 #ifdef max
  66 #undef max
  67 #endif
  68 #define max(a,b) ((a)>(b)?(a):(b))
  69 #ifdef min
  70 #undef min
  71 #endif
  72 #define min(a,b) ((a)<(b)?(a):(b))
  73
  74
  75 /****************************************************************************
  76  *
  77  * Local function declarations
  78  *
  79  ***************************************************************************/
  80
  81 static void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes);
  82 static void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes);
  83 static void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes);
  84 static FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes);
  85 static FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes);
  86 static FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes);
  87
  88 static FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator);
  89 static FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block);
  90 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);
  91 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);
  92 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_StreamInfo *block);
  93 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);
  94 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);
  95 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);
  96 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);
  97 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment *block);
  98 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet_Track *track);
  99 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet *block);
 100 static FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Picture *block);
 101 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);
 102
 103 static FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block);
 104 static FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block);
 105 static FLAC__bool write_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block);
 106 static FLAC__bool write_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block);
 107 static FLAC__bool write_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_StreamInfo *block);
 108 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);
 109 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);
 110 static FLAC__bool write_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_SeekTable *block);
 111 static FLAC__bool write_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_VorbisComment *block);
 112 static FLAC__bool write_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_CueSheet *block);
 113 static FLAC__bool write_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Picture *block);
 114 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);
 115
 116 static FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block);
 117 static FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last);
 118 static FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append);
 119
 120 static void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator);
 121 static FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator);
 122
 123 static unsigned seek_to_first_metadata_block_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb);
 124 static unsigned seek_to_first_metadata_block_(FILE *f);
 125
 126 static FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append);
 127 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);
 128
 129 static FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status);
 130 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);
 131 static FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status);
 132 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);
 133
 134 static FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status);
 135 static FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status);
 136 static void cleanup_tempfile_(FILE **tempfile, char **tempfilename);
 137
 138 static FLAC__bool get_file_stats_(const char *filename, struct stat *stats);
 139 static void set_file_stats_(const char *filename, struct stat *stats);
 140
 141 static int fseek_wrapper_(FLAC__IOHandle handle, FLAC__int64 offset, int whence);
 142 static FLAC__int64 ftell_wrapper_(FLAC__IOHandle handle);
 143
 144 static FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status);
 145
 146
 147 #ifdef FLAC__VALGRIND_TESTING
 148 static size_t local__fwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream)
 149 {
 150         size_t ret = fwrite(ptr, size, nmemb, stream);
 151         if(!ferror(stream))
 152                 fflush(stream);
 153         return ret;
 154 }
 155 #else
 156 #define local__fwrite fwrite
 157 #endif
 158
 159 /****************************************************************************
 160  *
 161  * Level 0 implementation
 162  *
 163  ***************************************************************************/
 164
 165 static FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data);
 166 static void metadata_callback_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data);
 167 static void error_callback_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data);
 168
 169 typedef struct {
 170         FLAC__bool got_error;
 171         FLAC__StreamMetadata *object;
 172 } level0_client_data;
 173
 174 static FLAC__StreamMetadata *get_one_metadata_block_(const char *filename, FLAC__MetadataType type)
 175 {
 176         level0_client_data cd;
 177         FLAC__StreamDecoder *decoder;
 178
 179         FLAC__ASSERT(0 != filename);
 180
 181         cd.got_error = false;
 182         cd.object = 0;
 183
 184         decoder = FLAC__stream_decoder_new();
 185
 186         if(0 == decoder)
 187                 return 0;
 188
 189         FLAC__stream_decoder_set_md5_checking(decoder, false);
 190         FLAC__stream_decoder_set_metadata_ignore_all(decoder);
 191         FLAC__stream_decoder_set_metadata_respond(decoder, type);
 192
 193         if(FLAC__stream_decoder_init_file(decoder, filename, write_callback_, metadata_callback_, error_callback_, &cd) != FLAC__STREAM_DECODER_INIT_STATUS_OK || cd.got_error) {
 194                 (void)FLAC__stream_decoder_finish(decoder);
 195                 FLAC__stream_decoder_delete(decoder);
 196                 return 0;
 197         }
 198
 199         if(!FLAC__stream_decoder_process_until_end_of_metadata(decoder) || cd.got_error) {
 200                 (void)FLAC__stream_decoder_finish(decoder);
 201                 FLAC__stream_decoder_delete(decoder);
 202                 if(0 != cd.object)
 203                         FLAC__metadata_object_delete(cd.object);
 204                 return 0;
 205         }
 206
 207         (void)FLAC__stream_decoder_finish(decoder);
 208         FLAC__stream_decoder_delete(decoder);
 209
 210         return cd.object;
 211 }
 212
 213 FLAC_API FLAC__bool FLAC__metadata_get_streaminfo(const char *filename, FLAC__StreamMetadata *streaminfo)
 214 {
 215         FLAC__StreamMetadata *object;
 216
 217         FLAC__ASSERT(0 != filename);
 218         FLAC__ASSERT(0 != streaminfo);
 219
 220         object = get_one_metadata_block_(filename, FLAC__METADATA_TYPE_STREAMINFO);
 221
 222         if (object) {
 223                 /* can just copy the contents since STREAMINFO has no internal structure */
 224                 *streaminfo = *object;
 225                 FLAC__metadata_object_delete(object);
 226                 return true;
 227         }
 228         else {
 229                 return false;
 230         }
 231 }
 232
 233 FLAC_API FLAC__bool FLAC__metadata_get_tags(const char *filename, FLAC__StreamMetadata **tags)
 234 {
 235         FLAC__ASSERT(0 != filename);
 236         FLAC__ASSERT(0 != tags);
 237
 238         *tags = get_one_metadata_block_(filename, FLAC__METADATA_TYPE_VORBIS_COMMENT);
 239
 240         return 0 != *tags;
 241 }
 242
 243 FLAC_API FLAC__bool FLAC__metadata_get_cuesheet(const char *filename, FLAC__StreamMetadata **cuesheet)
 244 {
 245         FLAC__ASSERT(0 != filename);
 246         FLAC__ASSERT(0 != cuesheet);
 247
 248         *cuesheet = get_one_metadata_block_(filename, FLAC__METADATA_TYPE_CUESHEET);
 249
 250         return 0 != *cuesheet;
 251 }
 252
 253 FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
 254 {
 255         (void)decoder, (void)frame, (void)buffer, (void)client_data;
 256
 257         return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;
 258 }
 259
 260 void metadata_callback_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
 261 {
 262         level0_client_data *cd = (level0_client_data *)client_data;
 263         (void)decoder;
 264
 265         /*
 266          * we assume we only get here when the one metadata block we were
 267          * looking for was passed to us
 268          */
 269         if(!cd->got_error && 0 == cd->object) {
 270                 if(0 == (cd->object = FLAC__metadata_object_clone(metadata)))
 271                         cd->got_error = true;
 272         }
 273 }
 274
 275 void error_callback_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
 276 {
 277         level0_client_data *cd = (level0_client_data *)client_data;
 278         (void)decoder;
 279
 280         if(status != FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC)
 281                 cd->got_error = true;
 282 }
 283
 284 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)
 285 {
 286         FLAC__Metadata_SimpleIterator *it;
 287         FLAC__uint64 max_area_seen = 0;
 288         FLAC__uint64 max_depth_seen = 0;
 289
 290         FLAC__ASSERT(0 != filename);
 291         FLAC__ASSERT(0 != picture);
 292
 293         *picture = 0;
 294
 295         it = FLAC__metadata_simple_iterator_new();
 296         if(0 == it)
 297                 return false;
 298         if(!FLAC__metadata_simple_iterator_init(it, filename, /*read_only=*/true, /*preserve_file_stats=*/true)) {
 299                 FLAC__metadata_simple_iterator_delete(it);
 300                 return false;
 301         }
 302         do {
 303                 if(FLAC__metadata_simple_iterator_get_block_type(it) == FLAC__METADATA_TYPE_PICTURE) {
 304                         FLAC__StreamMetadata *obj = FLAC__metadata_simple_iterator_get_block(it);
 305                         FLAC__uint64 area = (FLAC__uint64)obj->data.picture.width * (FLAC__uint64)obj->data.picture.height;
 306                         /* check constraints */
 307                         if(
 308                                 (type == (FLAC__StreamMetadata_Picture_Type)(-1) || type == obj->data.picture.type) &&
 309                                 (mime_type == 0 || !strcmp(mime_type, obj->data.picture.mime_type)) &&
 310                                 (description == 0 || !strcmp((const char *)description, (const char *)obj->data.picture.description)) &&
 311                                 obj->data.picture.width <= max_width &&
 312                                 obj->data.picture.height <= max_height &&
 313                                 obj->data.picture.depth <= max_depth &&
 314                                 obj->data.picture.colors <= max_colors &&
 315                                 (area > max_area_seen || (area == max_area_seen && obj->data.picture.depth > max_depth_seen))
 316                         ) {
 317                                 if(*picture)
 318                                         FLAC__metadata_object_delete(*picture);
 319                                 *picture = obj;
 320                                 max_area_seen = area;
 321                                 max_depth_seen = obj->data.picture.depth;
 322                         }
 323                         else {
 324                                 FLAC__metadata_object_delete(obj);
 325                         }
 326                 }
 327         } while(FLAC__metadata_simple_iterator_next(it));
 328
 329         FLAC__metadata_simple_iterator_delete(it);
 330
 331         return (0 != *picture);
 332 }
 333
 334
 335 /****************************************************************************
 336  *
 337  * Level 1 implementation
 338  *
 339  ***************************************************************************/
 340
 341 #define SIMPLE_ITERATOR_MAX_PUSH_DEPTH (1+4)
 342 /* 1 for initial offset, +4 for our own personal use */
 343
 344 struct FLAC__Metadata_SimpleIterator {
 345         FILE *file;
 346         char *filename, *tempfile_path_prefix;
 347         struct stat stats;
 348         FLAC__bool has_stats;
 349         FLAC__bool is_writable;
 350         FLAC__Metadata_SimpleIteratorStatus status;
 351         off_t offset[SIMPLE_ITERATOR_MAX_PUSH_DEPTH];
 352         off_t first_offset; /* this is the offset to the STREAMINFO block */
 353         unsigned depth;
 354         /* this is the metadata block header of the current block we are pointing to: */
 355         FLAC__bool is_last;
 356         FLAC__MetadataType type;
 357         unsigned length;
 358 };
 359
 360 FLAC_API const char * const FLAC__Metadata_SimpleIteratorStatusString[] = {
 361         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK",
 362         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT",
 363         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE",
 364         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE",
 365         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE",
 366         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA",
 367         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR",
 368         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR",
 369         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR",
 370         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR",
 371         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR",
 372         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR",
 373         "FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR"
 374 };
 375
 376
 377 FLAC_API FLAC__Metadata_SimpleIterator *FLAC__metadata_simple_iterator_new()
 378 {
 379         FLAC__Metadata_SimpleIterator *iterator = (FLAC__Metadata_SimpleIterator*)calloc(1, sizeof(FLAC__Metadata_SimpleIterator));
 380
 381         if(0 != iterator) {
 382                 iterator->file = 0;
 383                 iterator->filename = 0;
 384                 iterator->tempfile_path_prefix = 0;
 385                 iterator->has_stats = false;
 386                 iterator->is_writable = false;
 387                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
 388                 iterator->first_offset = iterator->offset[0] = -1;
 389                 iterator->depth = 0;
 390         }
 391
 392         return iterator;
 393 }
 394
 395 static void simple_iterator_free_guts_(FLAC__Metadata_SimpleIterator *iterator)
 396 {
 397         FLAC__ASSERT(0 != iterator);
 398
 399         if(0 != iterator->file) {
 400                 fclose(iterator->file);
 401                 iterator->file = 0;
 402                 if(iterator->has_stats)
 403                         set_file_stats_(iterator->filename, &iterator->stats);
 404         }
 405         if(0 != iterator->filename) {
 406                 free(iterator->filename);
 407                 iterator->filename = 0;
 408         }
 409         if(0 != iterator->tempfile_path_prefix) {
 410                 free(iterator->tempfile_path_prefix);
 411                 iterator->tempfile_path_prefix = 0;
 412         }
 413 }
 414
 415 FLAC_API void FLAC__metadata_simple_iterator_delete(FLAC__Metadata_SimpleIterator *iterator)
 416 {
 417         FLAC__ASSERT(0 != iterator);
 418
 419         simple_iterator_free_guts_(iterator);
 420         free(iterator);
 421 }
 422
 423 FLAC_API FLAC__Metadata_SimpleIteratorStatus FLAC__metadata_simple_iterator_status(FLAC__Metadata_SimpleIterator *iterator)
 424 {
 425         FLAC__Metadata_SimpleIteratorStatus status;
 426
 427         FLAC__ASSERT(0 != iterator);
 428
 429         status = iterator->status;
 430         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
 431         return status;
 432 }
 433
 434 static FLAC__bool simple_iterator_prime_input_(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool read_only)
 435 {
 436         unsigned ret;
 437
 438         FLAC__ASSERT(0 != iterator);
 439
 440         if(read_only || 0 == (iterator->file = fopen(iterator->filename, "r+b"))) {
 441                 iterator->is_writable = false;
 442                 if(read_only || errno == EACCES) {
 443                         if(0 == (iterator->file = fopen(iterator->filename, "rb"))) {
 444                                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
 445                                 return false;
 446                         }
 447                 }
 448                 else {
 449                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
 450                         return false;
 451                 }
 452         }
 453         else {
 454                 iterator->is_writable = true;
 455         }
 456
 457         ret = seek_to_first_metadata_block_(iterator->file);
 458         switch(ret) {
 459                 case 0:
 460                         iterator->depth = 0;
 461                         iterator->first_offset = iterator->offset[iterator->depth] = ftello(iterator->file);
 462                         return read_metadata_block_header_(iterator);
 463                 case 1:
 464                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
 465                         return false;
 466                 case 2:
 467                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 468                         return false;
 469                 case 3:
 470                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE;
 471                         return false;
 472                 default:
 473                         FLAC__ASSERT(0);
 474                         return false;
 475         }
 476 }
 477
 478 #if 0
 479 @@@ If we decide to finish implementing this, put this comment back in metadata.h
 480 /*
 481  * The 'tempfile_path_prefix' allows you to specify a directory where
 482  * tempfiles should go.  Remember that if your metadata edits cause the
 483  * FLAC file to grow, the entire file will have to be rewritten.  If
 484  * 'tempfile_path_prefix' is NULL, the temp file will be written in the
 485  * same directory as the original FLAC file.  This makes replacing the
 486  * original with the tempfile fast but requires extra space in the same
 487  * partition for the tempfile.  If space is a problem, you can pass a
 488  * directory name belonging to a different partition in
 489  * 'tempfile_path_prefix'.  Note that you should use the forward slash
 490  * '/' as the directory separator.  A trailing slash is not needed; it
 491  * will be added automatically.
 492  */
 493 FLAC__bool FLAC__metadata_simple_iterator_init(FLAC__Metadata_SimpleIterator *iterator, const char *filename, FLAC__bool preserve_file_stats, const char *tempfile_path_prefix);
 494 #endif
 495
 496 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)
 497 {
 498         const char *tempfile_path_prefix = 0; /*@@@ search for comments near 'rename(...)' for what it will take to finish implementing this */
 499
 500         FLAC__ASSERT(0 != iterator);
 501         FLAC__ASSERT(0 != filename);
 502
 503         simple_iterator_free_guts_(iterator);
 504
 505         if(!read_only && preserve_file_stats)
 506                 iterator->has_stats = get_file_stats_(filename, &iterator->stats);
 507
 508         if(0 == (iterator->filename = strdup(filename))) {
 509                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 510                 return false;
 511         }
 512         if(0 != tempfile_path_prefix && 0 == (iterator->tempfile_path_prefix = strdup(tempfile_path_prefix))) {
 513                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 514                 return false;
 515         }
 516
 517         return simple_iterator_prime_input_(iterator, read_only);
 518 }
 519
 520 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_is_writable(const FLAC__Metadata_SimpleIterator *iterator)
 521 {
 522         FLAC__ASSERT(0 != iterator);
 523         FLAC__ASSERT(0 != iterator->file);
 524
 525         return iterator->is_writable;
 526 }
 527
 528 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_next(FLAC__Metadata_SimpleIterator *iterator)
 529 {
 530         FLAC__ASSERT(0 != iterator);
 531         FLAC__ASSERT(0 != iterator->file);
 532
 533         if(iterator->is_last)
 534                 return false;
 535
 536         if(0 != fseeko(iterator->file, iterator->length, SEEK_CUR)) {
 537                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 538                 return false;
 539         }
 540
 541         iterator->offset[iterator->depth] = ftello(iterator->file);
 542
 543         return read_metadata_block_header_(iterator);
 544 }
 545
 546 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_prev(FLAC__Metadata_SimpleIterator *iterator)
 547 {
 548         off_t this_offset;
 549
 550         FLAC__ASSERT(0 != iterator);
 551         FLAC__ASSERT(0 != iterator->file);
 552
 553         if(iterator->offset[iterator->depth] == iterator->first_offset)
 554                 return false;
 555
 556         if(0 != fseeko(iterator->file, iterator->first_offset, SEEK_SET)) {
 557                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 558                 return false;
 559         }
 560         this_offset = iterator->first_offset;
 561         if(!read_metadata_block_header_(iterator))
 562                 return false;
 563
 564         /* we ignore any error from ftello() and catch it in fseeko() */
 565         while(ftello(iterator->file) + (off_t)iterator->length < iterator->offset[iterator->depth]) {
 566                 if(0 != fseeko(iterator->file, iterator->length, SEEK_CUR)) {
 567                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 568                         return false;
 569                 }
 570                 this_offset = ftello(iterator->file);
 571                 if(!read_metadata_block_header_(iterator))
 572                         return false;
 573         }
 574
 575         iterator->offset[iterator->depth] = this_offset;
 576
 577         return true;
 578 }
 579
 580 FLAC_API FLAC__MetadataType FLAC__metadata_simple_iterator_get_block_type(const FLAC__Metadata_SimpleIterator *iterator)
 581 {
 582         FLAC__ASSERT(0 != iterator);
 583         FLAC__ASSERT(0 != iterator->file);
 584
 585         return iterator->type;
 586 }
 587
 588 FLAC_API FLAC__StreamMetadata *FLAC__metadata_simple_iterator_get_block(FLAC__Metadata_SimpleIterator *iterator)
 589 {
 590         FLAC__StreamMetadata *block = FLAC__metadata_object_new(iterator->type);
 591
 592         FLAC__ASSERT(0 != iterator);
 593         FLAC__ASSERT(0 != iterator->file);
 594
 595         if(0 != block) {
 596                 block->is_last = iterator->is_last;
 597                 block->length = iterator->length;
 598
 599                 if(!read_metadata_block_data_(iterator, block)) {
 600                         FLAC__metadata_object_delete(block);
 601                         return 0;
 602                 }
 603
 604                 /* back up to the beginning of the block data to stay consistent */
 605                 if(0 != fseeko(iterator->file, iterator->offset[iterator->depth] + FLAC__STREAM_METADATA_HEADER_LENGTH, SEEK_SET)) {
 606                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
 607                         FLAC__metadata_object_delete(block);
 608                         return 0;
 609                 }
 610         }
 611         else
 612                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 613
 614         return block;
 615 }
 616
 617 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_set_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding)
 618 {
 619         FLAC__ASSERT_DECLARATION(off_t debug_target_offset = iterator->offset[iterator->depth];)
 620         FLAC__bool ret;
 621
 622         FLAC__ASSERT(0 != iterator);
 623         FLAC__ASSERT(0 != iterator->file);
 624         FLAC__ASSERT(0 != block);
 625
 626         if(!iterator->is_writable) {
 627                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE;
 628                 return false;
 629         }
 630
 631         if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO || block->type == FLAC__METADATA_TYPE_STREAMINFO) {
 632                 if(iterator->type != block->type) {
 633                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 634                         return false;
 635                 }
 636         }
 637
 638         block->is_last = iterator->is_last;
 639
 640         if(iterator->length == block->length)
 641                 return write_metadata_block_stationary_(iterator, block);
 642         else if(iterator->length > block->length) {
 643                 if(use_padding && iterator->length >= FLAC__STREAM_METADATA_HEADER_LENGTH + block->length) {
 644                         ret = write_metadata_block_stationary_with_padding_(iterator, block, iterator->length - FLAC__STREAM_METADATA_HEADER_LENGTH - block->length, block->is_last);
 645                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 646                         FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 647                         return ret;
 648                 }
 649                 else {
 650                         ret = rewrite_whole_file_(iterator, block, /*append=*/false);
 651                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 652                         FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 653                         return ret;
 654                 }
 655         }
 656         else /* iterator->length < block->length */ {
 657                 unsigned padding_leftover = 0;
 658                 FLAC__bool padding_is_last = false;
 659                 if(use_padding) {
 660                         /* first see if we can even use padding */
 661                         if(iterator->is_last) {
 662                                 use_padding = false;
 663                         }
 664                         else {
 665                                 const unsigned extra_padding_bytes_required = block->length - iterator->length;
 666                                 simple_iterator_push_(iterator);
 667                                 if(!FLAC__metadata_simple_iterator_next(iterator)) {
 668                                         (void)simple_iterator_pop_(iterator);
 669                                         return false;
 670                                 }
 671                                 if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
 672                                         use_padding = false;
 673                                 }
 674                                 else {
 675                                         if(FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length == extra_padding_bytes_required) {
 676                                                 padding_leftover = 0;
 677                                                 block->is_last = iterator->is_last;
 678                                         }
 679                                         else if(iterator->length < extra_padding_bytes_required)
 680                                                 use_padding = false;
 681                                         else {
 682                                                 padding_leftover = FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length - extra_padding_bytes_required;
 683                                                 padding_is_last = iterator->is_last;
 684                                                 block->is_last = false;
 685                                         }
 686                                 }
 687                                 if(!simple_iterator_pop_(iterator))
 688                                         return false;
 689                         }
 690                 }
 691                 if(use_padding) {
 692                         if(padding_leftover == 0) {
 693                                 ret = write_metadata_block_stationary_(iterator, block);
 694                                 FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 695                                 FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 696                                 return ret;
 697                         }
 698                         else {
 699                                 FLAC__ASSERT(padding_leftover >= FLAC__STREAM_METADATA_HEADER_LENGTH);
 700                                 ret = write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover - FLAC__STREAM_METADATA_HEADER_LENGTH, padding_is_last);
 701                                 FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 702                                 FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 703                                 return ret;
 704                         }
 705                 }
 706                 else {
 707                         ret = rewrite_whole_file_(iterator, block, /*append=*/false);
 708                         FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
 709                         FLAC__ASSERT(!ret || ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 710                         return ret;
 711                 }
 712         }
 713 }
 714
 715 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_insert_block_after(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding)
 716 {
 717         unsigned padding_leftover = 0;
 718         FLAC__bool padding_is_last = false;
 719
 720         FLAC__ASSERT_DECLARATION(off_t debug_target_offset = iterator->offset[iterator->depth] + FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length;)
 721         FLAC__bool ret;
 722
 723         FLAC__ASSERT(0 != iterator);
 724         FLAC__ASSERT(0 != iterator->file);
 725         FLAC__ASSERT(0 != block);
 726
 727         if(!iterator->is_writable)
 728                 return false;
 729
 730         if(block->type == FLAC__METADATA_TYPE_STREAMINFO) {
 731                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 732                 return false;
 733         }
 734
 735         block->is_last = iterator->is_last;
 736
 737         if(use_padding) {
 738                 /* first see if we can even use padding */
 739                 if(iterator->is_last) {
 740                         use_padding = false;
 741                 }
 742                 else {
 743                         simple_iterator_push_(iterator);
 744                         if(!FLAC__metadata_simple_iterator_next(iterator)) {
 745                                 (void)simple_iterator_pop_(iterator);
 746                                 return false;
 747                         }
 748                         if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
 749                                 use_padding = false;
 750                         }
 751                         else {
 752                                 if(iterator->length == block->length) {
 753                                         padding_leftover = 0;
 754                                         block->is_last = iterator->is_last;
 755                                 }
 756                                 else if(iterator->length < FLAC__STREAM_METADATA_HEADER_LENGTH + block->length)
 757                                         use_padding = false;
 758                                 else {
 759                                         padding_leftover = iterator->length - block->length;
 760                                         padding_is_last = iterator->is_last;
 761                                         block->is_last = false;
 762                                 }
 763                         }
 764                         if(!simple_iterator_pop_(iterator))
 765                                 return false;
 766                 }
 767         }
 768         if(use_padding) {
 769                 /* move to the next block, which is suitable padding */
 770                 if(!FLAC__metadata_simple_iterator_next(iterator))
 771                         return false;
 772                 if(padding_leftover == 0) {
 773                         ret = write_metadata_block_stationary_(iterator, block);
 774                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 775                         FLAC__ASSERT(ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 776                         return ret;
 777                 }
 778                 else {
 779                         FLAC__ASSERT(padding_leftover >= FLAC__STREAM_METADATA_HEADER_LENGTH);
 780                         ret = write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover - FLAC__STREAM_METADATA_HEADER_LENGTH, padding_is_last);
 781                         FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 782                         FLAC__ASSERT(ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 783                         return ret;
 784                 }
 785         }
 786         else {
 787                 ret = rewrite_whole_file_(iterator, block, /*append=*/true);
 788                 FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
 789                 FLAC__ASSERT(ftello(iterator->file) == debug_target_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH);
 790                 return ret;
 791         }
 792 }
 793
 794 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_delete_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool use_padding)
 795 {
 796         FLAC__ASSERT_DECLARATION(off_t debug_target_offset = iterator->offset[iterator->depth];)
 797         FLAC__bool ret;
 798
 799         if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO) {
 800                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
 801                 return false;
 802         }
 803
 804         if(use_padding) {
 805                 FLAC__StreamMetadata *padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING);
 806                 if(0 == padding) {
 807                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
 808                         return false;
 809                 }
 810                 padding->length = iterator->length;
 811                 if(!FLAC__metadata_simple_iterator_set_block(iterator, padding, false)) {
 812                         FLAC__metadata_object_delete(padding);
 813                         return false;
 814                 }
 815                 FLAC__metadata_object_delete(padding);
 816                 if(!FLAC__metadata_simple_iterator_prev(iterator))
 817                         return false;
 818                 FLAC__ASSERT(iterator->offset[iterator->depth] + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length == debug_target_offset);
 819                 FLAC__ASSERT(ftello(iterator->file) + (off_t)iterator->length == debug_target_offset);
 820                 return true;
 821         }
 822         else {
 823                 ret = rewrite_whole_file_(iterator, 0, /*append=*/false);
 824                 FLAC__ASSERT(iterator->offset[iterator->depth] + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length == debug_target_offset);
 825                 FLAC__ASSERT(ftello(iterator->file) + (off_t)iterator->length == debug_target_offset);
 826                 return ret;
 827         }
 828 }
 829
 830
 831
 832 /****************************************************************************
 833  *
 834  * Level 2 implementation
 835  *
 836  ***************************************************************************/
 837
 838
 839 typedef struct FLAC__Metadata_Node {
 840         FLAC__StreamMetadata *data;
 841         struct FLAC__Metadata_Node *prev, *next;
 842 } FLAC__Metadata_Node;
 843
 844 struct FLAC__Metadata_Chain {
 845         char *filename; /* will be NULL if using callbacks */
 846         FLAC__bool is_ogg;
 847         FLAC__Metadata_Node *head;
 848         FLAC__Metadata_Node *tail;
 849         unsigned nodes;
 850         FLAC__Metadata_ChainStatus status;
 851         off_t first_offset, last_offset;
 852         /*
 853          * This is the length of the chain initially read from the FLAC file.
 854          * it is used to compare against the current length to decide whether
 855          * or not the whole file has to be rewritten.
 856          */
 857         off_t initial_length;
 858         /* @@@ hacky, these are currently only needed by ogg reader */
 859         FLAC__IOHandle handle;
 860         FLAC__IOCallback_Read read_cb;
 861 };
 862
 863 struct FLAC__Metadata_Iterator {
 864         FLAC__Metadata_Chain *chain;
 865         FLAC__Metadata_Node *current;
 866 };
 867
 868 FLAC_API const char * const FLAC__Metadata_ChainStatusString[] = {
 869         "FLAC__METADATA_CHAIN_STATUS_OK",
 870         "FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT",
 871         "FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE",
 872         "FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE",
 873         "FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE",
 874         "FLAC__METADATA_CHAIN_STATUS_BAD_METADATA",
 875         "FLAC__METADATA_CHAIN_STATUS_READ_ERROR",
 876         "FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR",
 877         "FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR",
 878         "FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR",
 879         "FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR",
 880         "FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR",
 881         "FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR",
 882         "FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS",
 883         "FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH",
 884         "FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL"
 885 };
 886
 887
 888 static FLAC__Metadata_Node *node_new_()
 889 {
 890         return (FLAC__Metadata_Node*)calloc(1, sizeof(FLAC__Metadata_Node));
 891 }
 892
 893 static void node_delete_(FLAC__Metadata_Node *node)
 894 {
 895         FLAC__ASSERT(0 != node);
 896         if(0 != node->data)
 897                 FLAC__metadata_object_delete(node->data);
 898         free(node);
 899 }
 900
 901 static void chain_init_(FLAC__Metadata_Chain *chain)
 902 {
 903         FLAC__ASSERT(0 != chain);
 904
 905         chain->filename = 0;
 906         chain->is_ogg = false;
 907         chain->head = chain->tail = 0;
 908         chain->nodes = 0;
 909         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
 910         chain->initial_length = 0;
 911         chain->read_cb = 0;
 912 }
 913
 914 static void chain_clear_(FLAC__Metadata_Chain *chain)
 915 {
 916         FLAC__Metadata_Node *node, *next;
 917
 918         FLAC__ASSERT(0 != chain);
 919
 920         for(node = chain->head; node; ) {
 921                 next = node->next;
 922                 node_delete_(node);
 923                 node = next;
 924         }
 925
 926         if(0 != chain->filename)
 927                 free(chain->filename);
 928
 929         chain_init_(chain);
 930 }
 931
 932 static void chain_append_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 933 {
 934         FLAC__ASSERT(0 != chain);
 935         FLAC__ASSERT(0 != node);
 936         FLAC__ASSERT(0 != node->data);
 937
 938         node->next = node->prev = 0;
 939         node->data->is_last = true;
 940         if(0 != chain->tail)
 941                 chain->tail->data->is_last = false;
 942
 943         if(0 == chain->head)
 944                 chain->head = node;
 945         else {
 946                 FLAC__ASSERT(0 != chain->tail);
 947                 chain->tail->next = node;
 948                 node->prev = chain->tail;
 949         }
 950         chain->tail = node;
 951         chain->nodes++;
 952 }
 953
 954 static void chain_remove_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 955 {
 956         FLAC__ASSERT(0 != chain);
 957         FLAC__ASSERT(0 != node);
 958
 959         if(node == chain->head)
 960                 chain->head = node->next;
 961         else
 962                 node->prev->next = node->next;
 963
 964         if(node == chain->tail)
 965                 chain->tail = node->prev;
 966         else
 967                 node->next->prev = node->prev;
 968
 969         if(0 != chain->tail)
 970                 chain->tail->data->is_last = true;
 971
 972         chain->nodes--;
 973 }
 974
 975 static void chain_delete_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
 976 {
 977         chain_remove_node_(chain, node);
 978         node_delete_(node);
 979 }
 980
 981 static off_t chain_calculate_length_(FLAC__Metadata_Chain *chain)
 982 {
 983         const FLAC__Metadata_Node *node;
 984         off_t length = 0;
 985         for(node = chain->head; node; node = node->next)
 986                 length += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
 987         return length;
 988 }
 989
 990 static void iterator_insert_node_(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Node *node)
 991 {
 992         FLAC__ASSERT(0 != node);
 993         FLAC__ASSERT(0 != node->data);
 994         FLAC__ASSERT(0 != iterator);
 995         FLAC__ASSERT(0 != iterator->current);
 996         FLAC__ASSERT(0 != iterator->chain);
 997         FLAC__ASSERT(0 != iterator->chain->head);
 998         FLAC__ASSERT(0 != iterator->chain->tail);
 999
1000         node->data->is_last = false;
1001
1002         node->prev = iterator->current->prev;
1003         node->next = iterator->current;
1004
1005         if(0 == node->prev)
1006                 iterator->chain->head = node;
1007         else
1008                 node->prev->next = node;
1009
1010         iterator->current->prev = node;
1011
1012         iterator->chain->nodes++;
1013 }
1014
1015 static void iterator_insert_node_after_(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Node *node)
1016 {
1017         FLAC__ASSERT(0 != node);
1018         FLAC__ASSERT(0 != node->data);
1019         FLAC__ASSERT(0 != iterator);
1020         FLAC__ASSERT(0 != iterator->current);
1021         FLAC__ASSERT(0 != iterator->chain);
1022         FLAC__ASSERT(0 != iterator->chain->head);
1023         FLAC__ASSERT(0 != iterator->chain->tail);
1024
1025         iterator->current->data->is_last = false;
1026
1027         node->prev = iterator->current;
1028         node->next = iterator->current->next;
1029
1030         if(0 == node->next)
1031                 iterator->chain->tail = node;
1032         else
1033                 node->next->prev = node;
1034
1035         node->prev->next = node;
1036
1037         iterator->chain->tail->data->is_last = true;
1038
1039         iterator->chain->nodes++;
1040 }
1041
1042 /* return true iff node and node->next are both padding */
1043 static FLAC__bool chain_merge_adjacent_padding_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
1044 {
1045         if(node->data->type == FLAC__METADATA_TYPE_PADDING && 0 != node->next && node->next->data->type == FLAC__METADATA_TYPE_PADDING) {
1046                 const unsigned growth = FLAC__STREAM_METADATA_HEADER_LENGTH + node->next->data->length;
1047                 node->data->length += growth;
1048
1049                 chain_delete_node_(chain, node->next);
1050                 return true;
1051         }
1052         else
1053                 return false;
1054 }
1055
1056 /* Returns the new length of the chain, or 0 if there was an error. */
1057 /* WATCHOUT: This can get called multiple times before a write, so
1058  * it should still work when this happens.
1059  */
1060 /* WATCHOUT: Make sure to also update the logic in
1061  * FLAC__metadata_chain_check_if_tempfile_needed() if the logic here changes.
1062  */
1063 static off_t chain_prepare_for_write_(FLAC__Metadata_Chain *chain, FLAC__bool use_padding)
1064 {
1065         off_t current_length = chain_calculate_length_(chain);
1066
1067         if(use_padding) {
1068                 /* if the metadata shrank and the last block is padding, we just extend the last padding block */
1069                 if(current_length < chain->initial_length && chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1070                         const off_t delta = chain->initial_length - current_length;
1071                         chain->tail->data->length += delta;
1072                         current_length += delta;
1073                         FLAC__ASSERT(current_length == chain->initial_length);
1074                 }
1075                 /* if the metadata shrank more than 4 bytes then there's room to add another padding block */
1076                 else if(current_length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH <= chain->initial_length) {
1077                         FLAC__StreamMetadata *padding;
1078                         FLAC__Metadata_Node *node;
1079                         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING))) {
1080                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1081                                 return 0;
1082                         }
1083                         padding->length = chain->initial_length - (FLAC__STREAM_METADATA_HEADER_LENGTH + current_length);
1084                         if(0 == (node = node_new_())) {
1085                                 FLAC__metadata_object_delete(padding);
1086                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1087                                 return 0;
1088                         }
1089                         node->data = padding;
1090                         chain_append_node_(chain, node);
1091                         current_length = chain_calculate_length_(chain);
1092                         FLAC__ASSERT(current_length == chain->initial_length);
1093                 }
1094                 /* 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 */
1095                 else if(current_length > chain->initial_length) {
1096                         const off_t delta = current_length - chain->initial_length;
1097                         if(chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1098                                 /* if the delta is exactly the size of the last padding block, remove the padding block */
1099                                 if((off_t)chain->tail->data->length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH == delta) {
1100                                         chain_delete_node_(chain, chain->tail);
1101                                         current_length = chain_calculate_length_(chain);
1102                                         FLAC__ASSERT(current_length == chain->initial_length);
1103                                 }
1104                                 /* if there is at least 'delta' bytes of padding, trim the padding down */
1105                                 else if((off_t)chain->tail->data->length >= delta) {
1106                                         chain->tail->data->length -= delta;
1107                                         current_length -= delta;
1108                                         FLAC__ASSERT(current_length == chain->initial_length);
1109                                 }
1110                         }
1111                 }
1112         }
1113
1114         return current_length;
1115 }
1116
1117 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)
1118 {
1119         FLAC__Metadata_Node *node;
1120
1121         FLAC__ASSERT(0 != chain);
1122
1123         /* we assume we're already at the beginning of the file */
1124
1125         switch(seek_to_first_metadata_block_cb_(handle, read_cb, seek_cb)) {
1126                 case 0:
1127                         break;
1128                 case 1:
1129                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1130                         return false;
1131                 case 2:
1132                         chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1133                         return false;
1134                 case 3:
1135                         chain->status = FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE;
1136                         return false;
1137                 default:
1138                         FLAC__ASSERT(0);
1139                         return false;
1140         }
1141
1142         {
1143                 FLAC__int64 pos = tell_cb(handle);
1144                 if(pos < 0) {
1145                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1146                         return false;
1147                 }
1148                 chain->first_offset = (off_t)pos;
1149         }
1150
1151         {
1152                 FLAC__bool is_last;
1153                 FLAC__MetadataType type;
1154                 unsigned length;
1155
1156                 do {
1157                         node = node_new_();
1158                         if(0 == node) {
1159                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1160                                 return false;
1161                         }
1162
1163                         if(!read_metadata_block_header_cb_(handle, read_cb, &is_last, &type, &length)) {
1164                                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1165                                 return false;
1166                         }
1167
1168                         node->data = FLAC__metadata_object_new(type);
1169                         if(0 == node->data) {
1170                                 node_delete_(node);
1171                                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1172                                 return false;
1173                         }
1174
1175                         node->data->is_last = is_last;
1176                         node->data->length = length;
1177
1178                         chain->status = get_equivalent_status_(read_metadata_block_data_cb_(handle, read_cb, seek_cb, node->data));
1179                         if(chain->status != FLAC__METADATA_CHAIN_STATUS_OK) {
1180                                 node_delete_(node);
1181                                 return false;
1182                         }
1183                         chain_append_node_(chain, node);
1184                 } while(!is_last);
1185         }
1186
1187         {
1188                 FLAC__int64 pos = tell_cb(handle);
1189                 if(pos < 0) {
1190                         chain->status = FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
1191                         return false;
1192                 }
1193                 chain->last_offset = (off_t)pos;
1194         }
1195
1196         chain->initial_length = chain_calculate_length_(chain);
1197
1198         return true;
1199 }
1200
1201 FLAC__StreamDecoderReadStatus chain_read_ogg_read_cb_(const FLAC__StreamDecoder *decoder, FLAC__byte buffer[], size_t *bytes, void *client_data)
1202 {
1203         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1204         (void)decoder;
1205         if(*bytes > 0 && chain->status == FLAC__METADATA_CHAIN_STATUS_OK) {
1206                 *bytes = chain->read_cb(buffer, sizeof(FLAC__byte), *bytes, chain->handle);
1207                 if(*bytes == 0)
1208                         return FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM;
1209                 else
1210                         return FLAC__STREAM_DECODER_READ_STATUS_CONTINUE;
1211         }
1212         else
1213                 return FLAC__STREAM_DECODER_READ_STATUS_ABORT;
1214 }
1215
1216 static FLAC__StreamDecoderWriteStatus chain_read_ogg_write_cb_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
1217 {
1218         (void)decoder, (void)frame, (void)buffer, (void)client_data;
1219         return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
1220 }
1221
1222 static void chain_read_ogg_metadata_cb_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
1223 {
1224         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1225         FLAC__Metadata_Node *node;
1226
1227         (void)decoder;
1228
1229         node = node_new_();
1230         if(0 == node) {
1231                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1232                 return;
1233         }
1234
1235         node->data = FLAC__metadata_object_clone(metadata);
1236         if(0 == node->data) {
1237                 node_delete_(node);
1238                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1239                 return;
1240         }
1241
1242         chain_append_node_(chain, node);
1243 }
1244
1245 static void chain_read_ogg_error_cb_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
1246 {
1247         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)client_data;
1248         (void)decoder, (void)status;
1249         chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1250 }
1251
1252 static FLAC__bool chain_read_ogg_cb_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb)
1253 {
1254         FLAC__StreamDecoder *decoder;
1255
1256         FLAC__ASSERT(0 != chain);
1257
1258         /* we assume we're already at the beginning of the file */
1259
1260         chain->handle = handle;
1261         chain->read_cb = read_cb;
1262         if(0 == (decoder = FLAC__stream_decoder_new())) {
1263                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1264                 return false;
1265         }
1266         FLAC__stream_decoder_set_metadata_respond_all(decoder);
1267         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) {
1268                 FLAC__stream_decoder_delete(decoder);
1269                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1270                 return false;
1271         }
1272
1273         chain->first_offset = 0; /*@@@ wrong; will need to be set correctly to implement metadata writing for Ogg FLAC */
1274
1275         if(!FLAC__stream_decoder_process_until_end_of_metadata(decoder))
1276                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR; /*@@@ maybe needs better error code */
1277         if(chain->status != FLAC__METADATA_CHAIN_STATUS_OK) {
1278                 FLAC__stream_decoder_delete(decoder);
1279                 return false;
1280         }
1281
1282         FLAC__stream_decoder_delete(decoder);
1283
1284         chain->last_offset = 0; /*@@@ wrong; will need to be set correctly to implement metadata writing for Ogg FLAC */
1285
1286         chain->initial_length = chain_calculate_length_(chain);
1287
1288         return true;
1289 }
1290
1291 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)
1292 {
1293         FLAC__Metadata_Node *node;
1294
1295         FLAC__ASSERT(0 != chain);
1296         FLAC__ASSERT(0 != chain->head);
1297
1298         if(0 != seek_cb(handle, chain->first_offset, SEEK_SET)) {
1299                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1300                 return false;
1301         }
1302
1303         for(node = chain->head; node; node = node->next) {
1304                 if(!write_metadata_block_header_cb_(handle, write_cb, node->data)) {
1305                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1306                         return false;
1307                 }
1308                 if(!write_metadata_block_data_cb_(handle, write_cb, node->data)) {
1309                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1310                         return false;
1311                 }
1312         }
1313
1314         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1315
1316         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
1317         return true;
1318 }
1319
1320 static FLAC__bool chain_rewrite_metadata_in_place_(FLAC__Metadata_Chain *chain)
1321 {
1322         FILE *file;
1323         FLAC__bool ret;
1324
1325         FLAC__ASSERT(0 != chain->filename);
1326
1327         if(0 == (file = fopen(chain->filename, "r+b"))) {
1328                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1329                 return false;
1330         }
1331
1332         /* chain_rewrite_metadata_in_place_cb_() sets chain->status for us */
1333         ret = chain_rewrite_metadata_in_place_cb_(chain, (FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, fseek_wrapper_);
1334
1335         fclose(file);
1336
1337         return ret;
1338 }
1339
1340 static FLAC__bool chain_rewrite_file_(FLAC__Metadata_Chain *chain, const char *tempfile_path_prefix)
1341 {
1342         FILE *f, *tempfile;
1343         char *tempfilename;
1344         FLAC__Metadata_SimpleIteratorStatus status;
1345         const FLAC__Metadata_Node *node;
1346
1347         FLAC__ASSERT(0 != chain);
1348         FLAC__ASSERT(0 != chain->filename);
1349         FLAC__ASSERT(0 != chain->head);
1350
1351         /* copy the file prefix (data up to first metadata block */
1352         if(0 == (f = fopen(chain->filename, "rb"))) {
1353                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1354                 return false;
1355         }
1356         if(!open_tempfile_(chain->filename, tempfile_path_prefix, &tempfile, &tempfilename, &status)) {
1357                 chain->status = get_equivalent_status_(status);
1358                 cleanup_tempfile_(&tempfile, &tempfilename);
1359                 return false;
1360         }
1361         if(!copy_n_bytes_from_file_(f, tempfile, chain->first_offset, &status)) {
1362                 chain->status = get_equivalent_status_(status);
1363                 cleanup_tempfile_(&tempfile, &tempfilename);
1364                 return false;
1365         }
1366
1367         /* write the metadata */
1368         for(node = chain->head; node; node = node->next) {
1369                 if(!write_metadata_block_header_(tempfile, &status, node->data)) {
1370                         chain->status = get_equivalent_status_(status);
1371                         return false;
1372                 }
1373                 if(!write_metadata_block_data_(tempfile, &status, node->data)) {
1374                         chain->status = get_equivalent_status_(status);
1375                         return false;
1376                 }
1377         }
1378         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1379
1380         /* copy the file postfix (everything after the metadata) */
1381         if(0 != fseeko(f, chain->last_offset, SEEK_SET)) {
1382                 cleanup_tempfile_(&tempfile, &tempfilename);
1383                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1384                 return false;
1385         }
1386         if(!copy_remaining_bytes_from_file_(f, tempfile, &status)) {
1387                 cleanup_tempfile_(&tempfile, &tempfilename);
1388                 chain->status = get_equivalent_status_(status);
1389                 return false;
1390         }
1391
1392         /* move the tempfile on top of the original */
1393         (void)fclose(f);
1394         if(!transport_tempfile_(chain->filename, &tempfile, &tempfilename, &status))
1395                 return false;
1396
1397         return true;
1398 }
1399
1400 /* assumes 'handle' is already at beginning of file */
1401 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)
1402 {
1403         FLAC__Metadata_SimpleIteratorStatus status;
1404         const FLAC__Metadata_Node *node;
1405
1406         FLAC__ASSERT(0 != chain);
1407         FLAC__ASSERT(0 == chain->filename);
1408         FLAC__ASSERT(0 != chain->head);
1409
1410         /* copy the file prefix (data up to first metadata block */
1411         if(!copy_n_bytes_from_file_cb_(handle, read_cb, temp_handle, temp_write_cb, chain->first_offset, &status)) {
1412                 chain->status = get_equivalent_status_(status);
1413                 return false;
1414         }
1415
1416         /* write the metadata */
1417         for(node = chain->head; node; node = node->next) {
1418                 if(!write_metadata_block_header_cb_(temp_handle, temp_write_cb, node->data)) {
1419                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1420                         return false;
1421                 }
1422                 if(!write_metadata_block_data_cb_(temp_handle, temp_write_cb, node->data)) {
1423                         chain->status = FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
1424                         return false;
1425                 }
1426         }
1427         /*FLAC__ASSERT(fflush(), ftello() == chain->last_offset);*/
1428
1429         /* copy the file postfix (everything after the metadata) */
1430         if(0 != seek_cb(handle, chain->last_offset, SEEK_SET)) {
1431                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1432                 return false;
1433         }
1434         if(!copy_remaining_bytes_from_file_cb_(handle, read_cb, eof_cb, temp_handle, temp_write_cb, &status)) {
1435                 chain->status = get_equivalent_status_(status);
1436                 return false;
1437         }
1438
1439         return true;
1440 }
1441
1442 FLAC_API FLAC__Metadata_Chain *FLAC__metadata_chain_new()
1443 {
1444         FLAC__Metadata_Chain *chain = (FLAC__Metadata_Chain*)calloc(1, sizeof(FLAC__Metadata_Chain));
1445
1446         if(0 != chain)
1447                 chain_init_(chain);
1448
1449         return chain;
1450 }
1451
1452 FLAC_API void FLAC__metadata_chain_delete(FLAC__Metadata_Chain *chain)
1453 {
1454         FLAC__ASSERT(0 != chain);
1455
1456         chain_clear_(chain);
1457
1458         free(chain);
1459 }
1460
1461 FLAC_API FLAC__Metadata_ChainStatus FLAC__metadata_chain_status(FLAC__Metadata_Chain *chain)
1462 {
1463         FLAC__Metadata_ChainStatus status;
1464
1465         FLAC__ASSERT(0 != chain);
1466
1467         status = chain->status;
1468         chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
1469         return status;
1470 }
1471
1472 static FLAC__bool chain_read_(FLAC__Metadata_Chain *chain, const char *filename, FLAC__bool is_ogg)
1473 {
1474         FILE *file;
1475         FLAC__bool ret;
1476
1477         FLAC__ASSERT(0 != chain);
1478         FLAC__ASSERT(0 != filename);
1479
1480         chain_clear_(chain);
1481
1482         if(0 == (chain->filename = strdup(filename))) {
1483                 chain->status = FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
1484                 return false;
1485         }
1486
1487         chain->is_ogg = is_ogg;
1488
1489         if(0 == (file = fopen(filename, "rb"))) {
1490                 chain->status = FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
1491                 return false;
1492         }
1493
1494         /* the function also sets chain->status for us */
1495         ret = is_ogg?
1496                 chain_read_ogg_cb_(chain, file, (FLAC__IOCallback_Read)fread) :
1497                 chain_read_cb_(chain, file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, ftell_wrapper_)
1498         ;
1499
1500         fclose(file);
1501
1502         return ret;
1503 }
1504
1505 FLAC_API FLAC__bool FLAC__metadata_chain_read(FLAC__Metadata_Chain *chain, const char *filename)
1506 {
1507         return chain_read_(chain, filename, /*is_ogg=*/false);
1508 }
1509
1510 FLAC_API FLAC__bool FLAC__metadata_chain_read_ogg(FLAC__Metadata_Chain *chain, const char *filename)
1511 {
1512         return chain_read_(chain, filename, /*is_ogg=*/true);
1513 }
1514
1515 static FLAC__bool chain_read_with_callbacks_(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks, FLAC__bool is_ogg)
1516 {
1517         FLAC__bool ret;
1518
1519         FLAC__ASSERT(0 != chain);
1520
1521         chain_clear_(chain);
1522
1523         if (0 == callbacks.read || 0 == callbacks.seek || 0 == callbacks.tell) {
1524                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1525                 return false;
1526         }
1527
1528         chain->is_ogg = is_ogg;
1529
1530         /* rewind */
1531         if(0 != callbacks.seek(handle, 0, SEEK_SET)) {
1532                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1533                 return false;
1534         }
1535
1536         /* the function also sets chain->status for us */
1537         ret = is_ogg?
1538                 chain_read_ogg_cb_(chain, handle, callbacks.read) :
1539                 chain_read_cb_(chain, handle, callbacks.read, callbacks.seek, callbacks.tell)
1540         ;
1541
1542         return ret;
1543 }
1544
1545 FLAC_API FLAC__bool FLAC__metadata_chain_read_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1546 {
1547         return chain_read_with_callbacks_(chain, handle, callbacks, /*is_ogg=*/false);
1548 }
1549
1550 FLAC_API FLAC__bool FLAC__metadata_chain_read_ogg_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1551 {
1552         return chain_read_with_callbacks_(chain, handle, callbacks, /*is_ogg=*/true);
1553 }
1554
1555 FLAC_API FLAC__bool FLAC__metadata_chain_check_if_tempfile_needed(FLAC__Metadata_Chain *chain, FLAC__bool use_padding)
1556 {
1557         /* This does all the same checks that are in chain_prepare_for_write_()
1558          * but doesn't actually alter the chain.  Make sure to update the logic
1559          * here if chain_prepare_for_write_() changes.
1560          */
1561         const off_t current_length = chain_calculate_length_(chain);
1562
1563         FLAC__ASSERT(0 != chain);
1564
1565         if(use_padding) {
1566                 /* if the metadata shrank and the last block is padding, we just extend the last padding block */
1567                 if(current_length < chain->initial_length && chain->tail->data->type == FLAC__METADATA_TYPE_PADDING)
1568                         return false;
1569                 /* if the metadata shrank more than 4 bytes then there's room to add another padding block */
1570                 else if(current_length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH <= chain->initial_length)
1571                         return false;
1572                 /* 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 */
1573                 else if(current_length > chain->initial_length) {
1574                         const off_t delta = current_length - chain->initial_length;
1575                         if(chain->tail->data->type == FLAC__METADATA_TYPE_PADDING) {
1576                                 /* if the delta is exactly the size of the last padding block, remove the padding block */
1577                                 if((off_t)chain->tail->data->length + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH == delta)
1578                                         return false;
1579                                 /* if there is at least 'delta' bytes of padding, trim the padding down */
1580                                 else if((off_t)chain->tail->data->length >= delta)
1581                                         return false;
1582                         }
1583                 }
1584         }
1585
1586         return (current_length != chain->initial_length);
1587 }
1588
1589 FLAC_API FLAC__bool FLAC__metadata_chain_write(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__bool preserve_file_stats)
1590 {
1591         struct stat stats;
1592         const char *tempfile_path_prefix = 0;
1593         off_t current_length;
1594
1595         FLAC__ASSERT(0 != chain);
1596
1597         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1598                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1599                 return false;
1600         }
1601
1602         if (0 == chain->filename) {
1603                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1604                 return false;
1605         }
1606
1607         current_length = chain_prepare_for_write_(chain, use_padding);
1608
1609         /* a return value of 0 means there was an error; chain->status is already set */
1610         if (0 == current_length)
1611                 return false;
1612
1613         if(preserve_file_stats)
1614                 get_file_stats_(chain->filename, &stats);
1615
1616         if(current_length == chain->initial_length) {
1617                 if(!chain_rewrite_metadata_in_place_(chain))
1618                         return false;
1619         }
1620         else {
1621                 if(!chain_rewrite_file_(chain, tempfile_path_prefix))
1622                         return false;
1623
1624                 /* recompute lengths and offsets */
1625                 {
1626                         const FLAC__Metadata_Node *node;
1627                         chain->initial_length = current_length;
1628                         chain->last_offset = chain->first_offset;
1629                         for(node = chain->head; node; node = node->next)
1630                                 chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1631                 }
1632         }
1633
1634         if(preserve_file_stats)
1635                 set_file_stats_(chain->filename, &stats);
1636
1637         return true;
1638 }
1639
1640 FLAC_API FLAC__bool FLAC__metadata_chain_write_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks)
1641 {
1642         off_t current_length;
1643
1644         FLAC__ASSERT(0 != chain);
1645
1646         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1647                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1648                 return false;
1649         }
1650
1651         if (0 != chain->filename) {
1652                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1653                 return false;
1654         }
1655
1656         if (0 == callbacks.write || 0 == callbacks.seek) {
1657                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1658                 return false;
1659         }
1660
1661         if (FLAC__metadata_chain_check_if_tempfile_needed(chain, use_padding)) {
1662                 chain->status = FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL;
1663                 return false;
1664         }
1665
1666         current_length = chain_prepare_for_write_(chain, use_padding);
1667
1668         /* a return value of 0 means there was an error; chain->status is already set */
1669         if (0 == current_length)
1670                 return false;
1671
1672         FLAC__ASSERT(current_length == chain->initial_length);
1673
1674         return chain_rewrite_metadata_in_place_cb_(chain, handle, callbacks.write, callbacks.seek);
1675 }
1676
1677 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)
1678 {
1679         off_t current_length;
1680
1681         FLAC__ASSERT(0 != chain);
1682
1683         if (chain->is_ogg) { /* cannot write back to Ogg FLAC yet */
1684                 chain->status = FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
1685                 return false;
1686         }
1687
1688         if (0 != chain->filename) {
1689                 chain->status = FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH;
1690                 return false;
1691         }
1692
1693         if (0 == callbacks.read || 0 == callbacks.seek || 0 == callbacks.eof) {
1694                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1695                 return false;
1696         }
1697         if (0 == temp_callbacks.write) {
1698                 chain->status = FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS;
1699                 return false;
1700         }
1701
1702         if (!FLAC__metadata_chain_check_if_tempfile_needed(chain, use_padding)) {
1703                 chain->status = FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL;
1704                 return false;
1705         }
1706
1707         current_length = chain_prepare_for_write_(chain, use_padding);
1708
1709         /* a return value of 0 means there was an error; chain->status is already set */
1710         if (0 == current_length)
1711                 return false;
1712
1713         FLAC__ASSERT(current_length != chain->initial_length);
1714
1715         /* rewind */
1716         if(0 != callbacks.seek(handle, 0, SEEK_SET)) {
1717                 chain->status = FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
1718                 return false;
1719         }
1720
1721         if(!chain_rewrite_file_cb_(chain, handle, callbacks.read, callbacks.seek, callbacks.eof, temp_handle, temp_callbacks.write))
1722                 return false;
1723
1724         /* recompute lengths and offsets */
1725         {
1726                 const FLAC__Metadata_Node *node;
1727                 chain->initial_length = current_length;
1728                 chain->last_offset = chain->first_offset;
1729                 for(node = chain->head; node; node = node->next)
1730                         chain->last_offset += (FLAC__STREAM_METADATA_HEADER_LENGTH + node->data->length);
1731         }
1732
1733         return true;
1734 }
1735
1736 FLAC_API void FLAC__metadata_chain_merge_padding(FLAC__Metadata_Chain *chain)
1737 {
1738         FLAC__Metadata_Node *node;
1739
1740         FLAC__ASSERT(0 != chain);
1741
1742         for(node = chain->head; node; ) {
1743                 if(!chain_merge_adjacent_padding_(chain, node))
1744                         node = node->next;
1745         }
1746 }
1747
1748 FLAC_API void FLAC__metadata_chain_sort_padding(FLAC__Metadata_Chain *chain)
1749 {
1750         FLAC__Metadata_Node *node, *save;
1751         unsigned i;
1752
1753         FLAC__ASSERT(0 != chain);
1754
1755         /*
1756          * Don't try and be too smart... this simple algo is good enough for
1757          * the small number of nodes that we deal with.
1758          */
1759         for(i = 0, node = chain->head; i < chain->nodes; i++) {
1760                 if(node->data->type == FLAC__METADATA_TYPE_PADDING) {
1761                         save = node->next;
1762                         chain_remove_node_(chain, node);
1763                         chain_append_node_(chain, node);
1764                         node = save;
1765                 }
1766                 else {
1767                         node = node->next;
1768                 }
1769         }
1770
1771         FLAC__metadata_chain_merge_padding(chain);
1772 }
1773
1774
1775 FLAC_API FLAC__Metadata_Iterator *FLAC__metadata_iterator_new()
1776 {
1777         FLAC__Metadata_Iterator *iterator = (FLAC__Metadata_Iterator*)calloc(1, sizeof(FLAC__Metadata_Iterator));
1778
1779         /* calloc() implies:
1780                 iterator->current = 0;
1781                 iterator->chain = 0;
1782         */
1783
1784         return iterator;
1785 }
1786
1787 FLAC_API void FLAC__metadata_iterator_delete(FLAC__Metadata_Iterator *iterator)
1788 {
1789         FLAC__ASSERT(0 != iterator);
1790
1791         free(iterator);
1792 }
1793
1794 FLAC_API void FLAC__metadata_iterator_init(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Chain *chain)
1795 {
1796         FLAC__ASSERT(0 != iterator);
1797         FLAC__ASSERT(0 != chain);
1798         FLAC__ASSERT(0 != chain->head);
1799
1800         iterator->chain = chain;
1801         iterator->current = chain->head;
1802 }
1803
1804 FLAC_API FLAC__bool FLAC__metadata_iterator_next(FLAC__Metadata_Iterator *iterator)
1805 {
1806         FLAC__ASSERT(0 != iterator);
1807
1808         if(0 == iterator->current || 0 == iterator->current->next)
1809                 return false;
1810
1811         iterator->current = iterator->current->next;
1812         return true;
1813 }
1814
1815 FLAC_API FLAC__bool FLAC__metadata_iterator_prev(FLAC__Metadata_Iterator *iterator)
1816 {
1817         FLAC__ASSERT(0 != iterator);
1818
1819         if(0 == iterator->current || 0 == iterator->current->prev)
1820                 return false;
1821
1822         iterator->current = iterator->current->prev;
1823         return true;
1824 }
1825
1826 FLAC_API FLAC__MetadataType FLAC__metadata_iterator_get_block_type(const FLAC__Metadata_Iterator *iterator)
1827 {
1828         FLAC__ASSERT(0 != iterator);
1829         FLAC__ASSERT(0 != iterator->current);
1830         FLAC__ASSERT(0 != iterator->current->data);
1831
1832         return iterator->current->data->type;
1833 }
1834
1835 FLAC_API FLAC__StreamMetadata *FLAC__metadata_iterator_get_block(FLAC__Metadata_Iterator *iterator)
1836 {
1837         FLAC__ASSERT(0 != iterator);
1838         FLAC__ASSERT(0 != iterator->current);
1839
1840         return iterator->current->data;
1841 }
1842
1843 FLAC_API FLAC__bool FLAC__metadata_iterator_set_block(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1844 {
1845         FLAC__ASSERT(0 != iterator);
1846         FLAC__ASSERT(0 != block);
1847         return FLAC__metadata_iterator_delete_block(iterator, false) && FLAC__metadata_iterator_insert_block_after(iterator, block);
1848 }
1849
1850 FLAC_API FLAC__bool FLAC__metadata_iterator_delete_block(FLAC__Metadata_Iterator *iterator, FLAC__bool replace_with_padding)
1851 {
1852         FLAC__Metadata_Node *save;
1853
1854         FLAC__ASSERT(0 != iterator);
1855         FLAC__ASSERT(0 != iterator->current);
1856
1857         if(0 == iterator->current->prev) {
1858                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1859                 return false;
1860         }
1861
1862         save = iterator->current->prev;
1863
1864         if(replace_with_padding) {
1865                 FLAC__metadata_object_delete_data(iterator->current->data);
1866                 iterator->current->data->type = FLAC__METADATA_TYPE_PADDING;
1867         }
1868         else {
1869                 chain_delete_node_(iterator->chain, iterator->current);
1870         }
1871
1872         iterator->current = save;
1873         return true;
1874 }
1875
1876 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_before(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1877 {
1878         FLAC__Metadata_Node *node;
1879
1880         FLAC__ASSERT(0 != iterator);
1881         FLAC__ASSERT(0 != iterator->current);
1882         FLAC__ASSERT(0 != block);
1883
1884         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1885                 return false;
1886
1887         if(0 == iterator->current->prev) {
1888                 FLAC__ASSERT(iterator->current->data->type == FLAC__METADATA_TYPE_STREAMINFO);
1889                 return false;
1890         }
1891
1892         if(0 == (node = node_new_()))
1893                 return false;
1894
1895         node->data = block;
1896         iterator_insert_node_(iterator, node);
1897         iterator->current = node;
1898         return true;
1899 }
1900
1901 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_after(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block)
1902 {
1903         FLAC__Metadata_Node *node;
1904
1905         FLAC__ASSERT(0 != iterator);
1906         FLAC__ASSERT(0 != iterator->current);
1907         FLAC__ASSERT(0 != block);
1908
1909         if(block->type == FLAC__METADATA_TYPE_STREAMINFO)
1910                 return false;
1911
1912         if(0 == (node = node_new_()))
1913                 return false;
1914
1915         node->data = block;
1916         iterator_insert_node_after_(iterator, node);
1917         iterator->current = node;
1918         return true;
1919 }
1920
1921
1922 /****************************************************************************
1923  *
1924  * Local function definitions
1925  *
1926  ***************************************************************************/
1927
1928 void pack_uint32_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
1929 {
1930         unsigned i;
1931
1932         b += bytes;
1933
1934         for(i = 0; i < bytes; i++) {
1935                 *(--b) = (FLAC__byte)(val & 0xff);
1936                 val >>= 8;
1937         }
1938 }
1939
1940 void pack_uint32_little_endian_(FLAC__uint32 val, FLAC__byte *b, unsigned bytes)
1941 {
1942         unsigned i;
1943
1944         for(i = 0; i < bytes; i++) {
1945                 *(b++) = (FLAC__byte)(val & 0xff);
1946                 val >>= 8;
1947         }
1948 }
1949
1950 void pack_uint64_(FLAC__uint64 val, FLAC__byte *b, unsigned bytes)
1951 {
1952         unsigned i;
1953
1954         b += bytes;
1955
1956         for(i = 0; i < bytes; i++) {
1957                 *(--b) = (FLAC__byte)(val & 0xff);
1958                 val >>= 8;
1959         }
1960 }
1961
1962 FLAC__uint32 unpack_uint32_(FLAC__byte *b, unsigned bytes)
1963 {
1964         FLAC__uint32 ret = 0;
1965         unsigned i;
1966
1967         for(i = 0; i < bytes; i++)
1968                 ret = (ret << 8) | (FLAC__uint32)(*b++);
1969
1970         return ret;
1971 }
1972
1973 FLAC__uint32 unpack_uint32_little_endian_(FLAC__byte *b, unsigned bytes)
1974 {
1975         FLAC__uint32 ret = 0;
1976         unsigned i;
1977
1978         b += bytes;
1979
1980         for(i = 0; i < bytes; i++)
1981                 ret = (ret << 8) | (FLAC__uint32)(*--b);
1982
1983         return ret;
1984 }
1985
1986 FLAC__uint64 unpack_uint64_(FLAC__byte *b, unsigned bytes)
1987 {
1988         FLAC__uint64 ret = 0;
1989         unsigned i;
1990
1991         for(i = 0; i < bytes; i++)
1992                 ret = (ret << 8) | (FLAC__uint64)(*b++);
1993
1994         return ret;
1995 }
1996
1997 FLAC__bool read_metadata_block_header_(FLAC__Metadata_SimpleIterator *iterator)
1998 {
1999         FLAC__ASSERT(0 != iterator);
2000         FLAC__ASSERT(0 != iterator->file);
2001
2002         if(!read_metadata_block_header_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, &iterator->is_last, &iterator->type, &iterator->length)) {
2003                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2004                 return false;
2005         }
2006
2007         return true;
2008 }
2009
2010 FLAC__bool read_metadata_block_data_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block)
2011 {
2012         FLAC__ASSERT(0 != iterator);
2013         FLAC__ASSERT(0 != iterator->file);
2014
2015         iterator->status = read_metadata_block_data_cb_((FLAC__IOHandle)iterator->file, (FLAC__IOCallback_Read)fread, fseek_wrapper_, block);
2016
2017         return (iterator->status == FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK);
2018 }
2019
2020 FLAC__bool read_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__bool *is_last, FLAC__MetadataType *type, unsigned *length)
2021 {
2022         FLAC__byte raw_header[FLAC__STREAM_METADATA_HEADER_LENGTH];
2023
2024         if(read_cb(raw_header, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
2025                 return false;
2026
2027         *is_last = raw_header[0] & 0x80? true : false;
2028         *type = (FLAC__MetadataType)(raw_header[0] & 0x7f);
2029         *length = unpack_uint32_(raw_header + 1, 3);
2030
2031         /* Note that we don't check:
2032          *    if(iterator->type >= FLAC__METADATA_TYPE_UNDEFINED)
2033          * we just will read in an opaque block
2034          */
2035
2036         return true;
2037 }
2038
2039 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata *block)
2040 {
2041         switch(block->type) {
2042                 case FLAC__METADATA_TYPE_STREAMINFO:
2043                         return read_metadata_block_data_streaminfo_cb_(handle, read_cb, &block->data.stream_info);
2044                 case FLAC__METADATA_TYPE_PADDING:
2045                         return read_metadata_block_data_padding_cb_(handle, seek_cb, &block->data.padding, block->length);
2046                 case FLAC__METADATA_TYPE_APPLICATION:
2047                         return read_metadata_block_data_application_cb_(handle, read_cb, &block->data.application, block->length);
2048                 case FLAC__METADATA_TYPE_SEEKTABLE:
2049                         return read_metadata_block_data_seektable_cb_(handle, read_cb, &block->data.seek_table, block->length);
2050                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
2051                         return read_metadata_block_data_vorbis_comment_cb_(handle, read_cb, &block->data.vorbis_comment);
2052                 case FLAC__METADATA_TYPE_CUESHEET:
2053                         return read_metadata_block_data_cuesheet_cb_(handle, read_cb, &block->data.cue_sheet);
2054                 case FLAC__METADATA_TYPE_PICTURE:
2055                         return read_metadata_block_data_picture_cb_(handle, read_cb, &block->data.picture);
2056                 default:
2057                         return read_metadata_block_data_unknown_cb_(handle, read_cb, &block->data.unknown, block->length);
2058         }
2059 }
2060
2061 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_StreamInfo *block)
2062 {
2063         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH], *b;
2064
2065         if(read_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
2066                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2067
2068         b = buffer;
2069
2070         /* we are using hardcoded numbers for simplicity but we should
2071          * probably eventually write a bit-level unpacker and use the
2072          * _STREAMINFO_ constants.
2073          */
2074         block->min_blocksize = unpack_uint32_(b, 2); b += 2;
2075         block->max_blocksize = unpack_uint32_(b, 2); b += 2;
2076         block->min_framesize = unpack_uint32_(b, 3); b += 3;
2077         block->max_framesize = unpack_uint32_(b, 3); b += 3;
2078         block->sample_rate = (unpack_uint32_(b, 2) << 4) | ((unsigned)(b[2] & 0xf0) >> 4);
2079         block->channels = (unsigned)((b[2] & 0x0e) >> 1) + 1;
2080         block->bits_per_sample = ((((unsigned)(b[2] & 0x01)) << 4) | (((unsigned)(b[3] & 0xf0)) >> 4)) + 1;
2081         block->total_samples = (((FLAC__uint64)(b[3] & 0x0f)) << 32) | unpack_uint64_(b+4, 4);
2082         memcpy(block->md5sum, b+8, 16);
2083
2084         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2085 }
2086
2087 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Seek seek_cb, FLAC__StreamMetadata_Padding *block, unsigned block_length)
2088 {
2089         (void)block; /* nothing to do; we don't care about reading the padding bytes */
2090
2091         if(0 != seek_cb(handle, block_length, SEEK_CUR))
2092                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2093
2094         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2095 }
2096
2097 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Application *block, unsigned block_length)
2098 {
2099         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
2100
2101         if(read_cb(block->id, 1, id_bytes, handle) != id_bytes)
2102                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2103
2104         block_length -= id_bytes;
2105
2106         if(block_length == 0) {
2107                 block->data = 0;
2108         }
2109         else {
2110                 if(0 == (block->data = (FLAC__byte*)malloc(block_length)))
2111                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2112
2113                 if(read_cb(block->data, 1, block_length, handle) != block_length)
2114                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2115         }
2116
2117         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2118 }
2119
2120 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_SeekTable *block, unsigned block_length)
2121 {
2122         unsigned i;
2123         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
2124
2125         FLAC__ASSERT(block_length % FLAC__STREAM_METADATA_SEEKPOINT_LENGTH == 0);
2126
2127         block->num_points = block_length / FLAC__STREAM_METADATA_SEEKPOINT_LENGTH;
2128
2129         if(block->num_points == 0)
2130                 block->points = 0;
2131         else if(0 == (block->points = (FLAC__StreamMetadata_SeekPoint*)malloc(block->num_points * sizeof(FLAC__StreamMetadata_SeekPoint))))
2132                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2133
2134         for(i = 0; i < block->num_points; i++) {
2135                 if(read_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
2136                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2137                 /* some MAGIC NUMBERs here */
2138                 block->points[i].sample_number = unpack_uint64_(buffer, 8);
2139                 block->points[i].stream_offset = unpack_uint64_(buffer+8, 8);
2140                 block->points[i].frame_samples = unpack_uint32_(buffer+16, 2);
2141         }
2142
2143         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2144 }
2145
2146 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_entry_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment_Entry *entry)
2147 {
2148         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
2149         FLAC__byte buffer[4]; /* magic number is asserted below */
2150
2151         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8 == sizeof(buffer));
2152
2153         if(read_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2154                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2155         entry->length = unpack_uint32_little_endian_(buffer, entry_length_len);
2156
2157         if(0 != entry->entry)
2158                 free(entry->entry);
2159
2160         if(entry->length == 0) {
2161                 entry->entry = 0;
2162         }
2163         else {
2164                 if(0 == (entry->entry = (FLAC__byte*)malloc(entry->length+1)))
2165                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2166
2167                 if(read_cb(entry->entry, 1, entry->length, handle) != entry->length)
2168                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2169
2170                 entry->entry[entry->length] = '\0';
2171         }
2172
2173         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2174 }
2175
2176 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_VorbisComment *block)
2177 {
2178         unsigned i;
2179         FLAC__Metadata_SimpleIteratorStatus status;
2180         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2181         FLAC__byte buffer[4]; /* magic number is asserted below */
2182
2183         FLAC__ASSERT(FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8 == sizeof(buffer));
2184
2185         if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, &(block->vendor_string))))
2186                 return status;
2187
2188         if(read_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2189                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2190         block->num_comments = unpack_uint32_little_endian_(buffer, num_comments_len);
2191
2192         if(block->num_comments == 0) {
2193                 block->comments = 0;
2194         }
2195         else if(0 == (block->comments = (FLAC__StreamMetadata_VorbisComment_Entry*)calloc(block->num_comments, sizeof(FLAC__StreamMetadata_VorbisComment_Entry))))
2196                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2197
2198         for(i = 0; i < block->num_comments; i++) {
2199                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_vorbis_comment_entry_cb_(handle, read_cb, block->comments + i)))
2200                         return status;
2201         }
2202
2203         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2204 }
2205
2206 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_track_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet_Track *track)
2207 {
2208         unsigned i, len;
2209         FLAC__byte buffer[32]; /* asserted below that this is big enough */
2210
2211         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2212         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2213         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);
2214
2215         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2216         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2217         if(read_cb(buffer, 1, len, handle) != len)
2218                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2219         track->offset = unpack_uint64_(buffer, len);
2220
2221         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2222         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2223         if(read_cb(buffer, 1, len, handle) != len)
2224                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2225         track->number = (FLAC__byte)unpack_uint32_(buffer, len);
2226
2227         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2228         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2229         if(read_cb(track->isrc, 1, len, handle) != len)
2230                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2231
2232         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);
2233         len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2234         if(read_cb(buffer, 1, len, handle) != len)
2235                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2236         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN == 1);
2237         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN == 1);
2238         track->type = buffer[0] >> 7;
2239         track->pre_emphasis = (buffer[0] >> 6) & 1;
2240
2241         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2242         len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2243         if(read_cb(buffer, 1, len, handle) != len)
2244                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2245         track->num_indices = (FLAC__byte)unpack_uint32_(buffer, len);
2246
2247         if(track->num_indices == 0) {
2248                 track->indices = 0;
2249         }
2250         else if(0 == (track->indices = (FLAC__StreamMetadata_CueSheet_Index*)calloc(track->num_indices, sizeof(FLAC__StreamMetadata_CueSheet_Index))))
2251                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2252
2253         for(i = 0; i < track->num_indices; i++) {
2254                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2255                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2256                 if(read_cb(buffer, 1, len, handle) != len)
2257                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2258                 track->indices[i].offset = unpack_uint64_(buffer, len);
2259
2260                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2261                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2262                 if(read_cb(buffer, 1, len, handle) != len)
2263                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2264                 track->indices[i].number = (FLAC__byte)unpack_uint32_(buffer, len);
2265
2266                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2267                 len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2268                 if(read_cb(buffer, 1, len, handle) != len)
2269                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2270         }
2271
2272         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2273 }
2274
2275 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_CueSheet *block)
2276 {
2277         unsigned i, len;
2278         FLAC__Metadata_SimpleIteratorStatus status;
2279         FLAC__byte buffer[1024]; /* MSVC needs a constant expression so we put a magic number and assert */
2280
2281         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN)/8 <= sizeof(buffer));
2282         FLAC__ASSERT(sizeof(FLAC__uint64) <= sizeof(buffer));
2283
2284         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2285         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2286         if(read_cb(block->media_catalog_number, 1, len, handle) != len)
2287                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2288
2289         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2290         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2291         if(read_cb(buffer, 1, len, handle) != len)
2292                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2293         block->lead_in = unpack_uint64_(buffer, len);
2294
2295         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2296         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2297         if(read_cb(buffer, 1, len, handle) != len)
2298                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2299         block->is_cd = buffer[0]&0x80? true : false;
2300
2301         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2302         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2303         if(read_cb(buffer, 1, len, handle) != len)
2304                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2305         block->num_tracks = unpack_uint32_(buffer, len);
2306
2307         if(block->num_tracks == 0) {
2308                 block->tracks = 0;
2309         }
2310         else if(0 == (block->tracks = (FLAC__StreamMetadata_CueSheet_Track*)calloc(block->num_tracks, sizeof(FLAC__StreamMetadata_CueSheet_Track))))
2311                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2312
2313         for(i = 0; i < block->num_tracks; i++) {
2314                 if(FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK != (status = read_metadata_block_data_cuesheet_track_cb_(handle, read_cb, block->tracks + i)))
2315                         return status;
2316         }
2317
2318         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2319 }
2320
2321 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)
2322 {
2323         FLAC__byte buffer[sizeof(FLAC__uint32)];
2324
2325         FLAC__ASSERT(0 != data);
2326         FLAC__ASSERT(length_len%8 == 0);
2327
2328         length_len /= 8; /* convert to bytes */
2329
2330         FLAC__ASSERT(sizeof(buffer) >= length_len);
2331
2332         if(read_cb(buffer, 1, length_len, handle) != length_len)
2333                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2334         *length = unpack_uint32_(buffer, length_len);
2335
2336         if(0 != *data)
2337                 free(*data);
2338
2339         if(0 == (*data = (FLAC__byte*)malloc(*length+1)))
2340                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2341
2342         if(*length > 0) {
2343                 if(read_cb(*data, 1, *length, handle) != *length)
2344                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2345         }
2346
2347         (*data)[*length] = '\0';
2348
2349         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2350 }
2351
2352 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Picture *block)
2353 {
2354         FLAC__Metadata_SimpleIteratorStatus status;
2355         FLAC__byte buffer[4]; /* asserted below that this is big enough */
2356         FLAC__uint32 len;
2357
2358         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8);
2359         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8);
2360         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8);
2361         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8);
2362         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8);
2363
2364         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_TYPE_LEN % 8 == 0);
2365         len = FLAC__STREAM_METADATA_PICTURE_TYPE_LEN / 8;
2366         if(read_cb(buffer, 1, len, handle) != len)
2367                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2368         block->type = (FLAC__StreamMetadata_Picture_Type)unpack_uint32_(buffer, len);
2369
2370         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)
2371                 return status;
2372
2373         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)
2374                 return status;
2375
2376         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN % 8 == 0);
2377         len = FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN / 8;
2378         if(read_cb(buffer, 1, len, handle) != len)
2379                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2380         block->width = unpack_uint32_(buffer, len);
2381
2382         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN % 8 == 0);
2383         len = FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN / 8;
2384         if(read_cb(buffer, 1, len, handle) != len)
2385                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2386         block->height = unpack_uint32_(buffer, len);
2387
2388         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN % 8 == 0);
2389         len = FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN / 8;
2390         if(read_cb(buffer, 1, len, handle) != len)
2391                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2392         block->depth = unpack_uint32_(buffer, len);
2393
2394         FLAC__ASSERT(FLAC__STREAM_METADATA_PICTURE_COLORS_LEN % 8 == 0);
2395         len = FLAC__STREAM_METADATA_PICTURE_COLORS_LEN / 8;
2396         if(read_cb(buffer, 1, len, handle) != len)
2397                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2398         block->colors = unpack_uint32_(buffer, len);
2399
2400         /* for convenience we use read_metadata_block_data_picture_cstring_cb_() even though it adds an extra terminating NUL we don't use */
2401         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)
2402                 return status;
2403
2404         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2405 }
2406
2407 FLAC__Metadata_SimpleIteratorStatus read_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2408 {
2409         if(block_length == 0) {
2410                 block->data = 0;
2411         }
2412         else {
2413                 if(0 == (block->data = (FLAC__byte*)malloc(block_length)))
2414                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2415
2416                 if(read_cb(block->data, 1, block_length, handle) != block_length)
2417                         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
2418         }
2419
2420         return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2421 }
2422
2423 FLAC__bool write_metadata_block_header_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2424 {
2425         FLAC__ASSERT(0 != file);
2426         FLAC__ASSERT(0 != status);
2427
2428         if(!write_metadata_block_header_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2429                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2430                 return false;
2431         }
2432
2433         return true;
2434 }
2435
2436 FLAC__bool write_metadata_block_data_(FILE *file, FLAC__Metadata_SimpleIteratorStatus *status, const FLAC__StreamMetadata *block)
2437 {
2438         FLAC__ASSERT(0 != file);
2439         FLAC__ASSERT(0 != status);
2440
2441         if (write_metadata_block_data_cb_((FLAC__IOHandle)file, (FLAC__IOCallback_Write)fwrite, block)) {
2442                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK;
2443                 return true;
2444         }
2445         else {
2446                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
2447                 return false;
2448         }
2449 }
2450
2451 FLAC__bool write_metadata_block_header_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2452 {
2453         FLAC__byte buffer[FLAC__STREAM_METADATA_HEADER_LENGTH];
2454
2455         FLAC__ASSERT(block->length < (1u << FLAC__STREAM_METADATA_LENGTH_LEN));
2456
2457         buffer[0] = (block->is_last? 0x80 : 0) | (FLAC__byte)block->type;
2458         pack_uint32_(block->length, buffer + 1, 3);
2459
2460         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_HEADER_LENGTH, handle) != FLAC__STREAM_METADATA_HEADER_LENGTH)
2461                 return false;
2462
2463         return true;
2464 }
2465
2466 FLAC__bool write_metadata_block_data_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata *block)
2467 {
2468         FLAC__ASSERT(0 != block);
2469
2470         switch(block->type) {
2471                 case FLAC__METADATA_TYPE_STREAMINFO:
2472                         return write_metadata_block_data_streaminfo_cb_(handle, write_cb, &block->data.stream_info);
2473                 case FLAC__METADATA_TYPE_PADDING:
2474                         return write_metadata_block_data_padding_cb_(handle, write_cb, &block->data.padding, block->length);
2475                 case FLAC__METADATA_TYPE_APPLICATION:
2476                         return write_metadata_block_data_application_cb_(handle, write_cb, &block->data.application, block->length);
2477                 case FLAC__METADATA_TYPE_SEEKTABLE:
2478                         return write_metadata_block_data_seektable_cb_(handle, write_cb, &block->data.seek_table);
2479                 case FLAC__METADATA_TYPE_VORBIS_COMMENT:
2480                         return write_metadata_block_data_vorbis_comment_cb_(handle, write_cb, &block->data.vorbis_comment);
2481                 case FLAC__METADATA_TYPE_CUESHEET:
2482                         return write_metadata_block_data_cuesheet_cb_(handle, write_cb, &block->data.cue_sheet);
2483                 case FLAC__METADATA_TYPE_PICTURE:
2484                         return write_metadata_block_data_picture_cb_(handle, write_cb, &block->data.picture);
2485                 default:
2486                         return write_metadata_block_data_unknown_cb_(handle, write_cb, &block->data.unknown, block->length);
2487         }
2488 }
2489
2490 FLAC__bool write_metadata_block_data_streaminfo_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_StreamInfo *block)
2491 {
2492         FLAC__byte buffer[FLAC__STREAM_METADATA_STREAMINFO_LENGTH];
2493         const unsigned channels1 = block->channels - 1;
2494         const unsigned bps1 = block->bits_per_sample - 1;
2495
2496         /* we are using hardcoded numbers for simplicity but we should
2497          * probably eventually write a bit-level packer and use the
2498          * _STREAMINFO_ constants.
2499          */
2500         pack_uint32_(block->min_blocksize, buffer, 2);
2501         pack_uint32_(block->max_blocksize, buffer+2, 2);
2502         pack_uint32_(block->min_framesize, buffer+4, 3);
2503         pack_uint32_(block->max_framesize, buffer+7, 3);
2504         buffer[10] = (block->sample_rate >> 12) & 0xff;
2505         buffer[11] = (block->sample_rate >> 4) & 0xff;
2506         buffer[12] = ((block->sample_rate & 0x0f) << 4) | (channels1 << 1) | (bps1 >> 4);
2507         buffer[13] = (FLAC__byte)(((bps1 & 0x0f) << 4) | ((block->total_samples >> 32) & 0x0f));
2508         pack_uint32_((FLAC__uint32)block->total_samples, buffer+14, 4);
2509         memcpy(buffer+18, block->md5sum, 16);
2510
2511         if(write_cb(buffer, 1, FLAC__STREAM_METADATA_STREAMINFO_LENGTH, handle) != FLAC__STREAM_METADATA_STREAMINFO_LENGTH)
2512                 return false;
2513
2514         return true;
2515 }
2516
2517 FLAC__bool write_metadata_block_data_padding_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Padding *block, unsigned block_length)
2518 {
2519         unsigned i, n = block_length;
2520         FLAC__byte buffer[1024];
2521
2522         (void)block;
2523
2524         memset(buffer, 0, 1024);
2525
2526         for(i = 0; i < n/1024; i++)
2527                 if(write_cb(buffer, 1, 1024, handle) != 1024)
2528                         return false;
2529
2530         n %= 1024;
2531
2532         if(write_cb(buffer, 1, n, handle) != n)
2533                 return false;
2534
2535         return true;
2536 }
2537
2538 FLAC__bool write_metadata_block_data_application_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Application *block, unsigned block_length)
2539 {
2540         const unsigned id_bytes = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
2541
2542         if(write_cb(block->id, 1, id_bytes, handle) != id_bytes)
2543                 return false;
2544
2545         block_length -= id_bytes;
2546
2547         if(write_cb(block->data, 1, block_length, handle) != block_length)
2548                 return false;
2549
2550         return true;
2551 }
2552
2553 FLAC__bool write_metadata_block_data_seektable_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_SeekTable *block)
2554 {
2555         unsigned i;
2556         FLAC__byte buffer[FLAC__STREAM_METADATA_SEEKPOINT_LENGTH];
2557
2558         for(i = 0; i < block->num_points; i++) {
2559                 /* some MAGIC NUMBERs here */
2560                 pack_uint64_(block->points[i].sample_number, buffer, 8);
2561                 pack_uint64_(block->points[i].stream_offset, buffer+8, 8);
2562                 pack_uint32_(block->points[i].frame_samples, buffer+16, 2);
2563                 if(write_cb(buffer, 1, FLAC__STREAM_METADATA_SEEKPOINT_LENGTH, handle) != FLAC__STREAM_METADATA_SEEKPOINT_LENGTH)
2564                         return false;
2565         }
2566
2567         return true;
2568 }
2569
2570 FLAC__bool write_metadata_block_data_vorbis_comment_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_VorbisComment *block)
2571 {
2572         unsigned i;
2573         const unsigned entry_length_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8;
2574         const unsigned num_comments_len = FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN / 8;
2575         FLAC__byte buffer[4]; /* magic number is asserted below */
2576
2577         FLAC__ASSERT(max(FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN, FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN) / 8 == sizeof(buffer));
2578
2579         pack_uint32_little_endian_(block->vendor_string.length, buffer, entry_length_len);
2580         if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2581                 return false;
2582         if(write_cb(block->vendor_string.entry, 1, block->vendor_string.length, handle) != block->vendor_string.length)
2583                 return false;
2584
2585         pack_uint32_little_endian_(block->num_comments, buffer, num_comments_len);
2586         if(write_cb(buffer, 1, num_comments_len, handle) != num_comments_len)
2587                 return false;
2588
2589         for(i = 0; i < block->num_comments; i++) {
2590                 pack_uint32_little_endian_(block->comments[i].length, buffer, entry_length_len);
2591                 if(write_cb(buffer, 1, entry_length_len, handle) != entry_length_len)
2592                         return false;
2593                 if(write_cb(block->comments[i].entry, 1, block->comments[i].length, handle) != block->comments[i].length)
2594                         return false;
2595         }
2596
2597         return true;
2598 }
2599
2600 FLAC__bool write_metadata_block_data_cuesheet_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_CueSheet *block)
2601 {
2602         unsigned i, j, len;
2603         FLAC__byte buffer[1024]; /* asserted below that this is big enough */
2604
2605         FLAC__ASSERT(sizeof(buffer) >= sizeof(FLAC__uint64));
2606         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN/8);
2607         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);
2608         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN/8);
2609
2610         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN % 8 == 0);
2611         len = FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN / 8;
2612         if(write_cb(block->media_catalog_number, 1, len, handle) != len)
2613                 return false;
2614
2615         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN % 8 == 0);
2616         len = FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN / 8;
2617         pack_uint64_(block->lead_in, buffer, len);
2618         if(write_cb(buffer, 1, len, handle) != len)
2619                 return false;
2620
2621         FLAC__ASSERT((FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) % 8 == 0);
2622         len = (FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN + FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN) / 8;
2623         memset(buffer, 0, len);
2624         if(block->is_cd)
2625                 buffer[0] |= 0x80;
2626         if(write_cb(buffer, 1, len, handle) != len)
2627                 return false;
2628
2629         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN % 8 == 0);
2630         len = FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN / 8;
2631         pack_uint32_(block->num_tracks, buffer, len);
2632         if(write_cb(buffer, 1, len, handle) != len)
2633                 return false;
2634
2635         for(i = 0; i < block->num_tracks; i++) {
2636                 FLAC__StreamMetadata_CueSheet_Track *track = block->tracks + i;
2637
2638                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN % 8 == 0);
2639                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN / 8;
2640                 pack_uint64_(track->offset, buffer, len);
2641                 if(write_cb(buffer, 1, len, handle) != len)
2642                         return false;
2643
2644                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN % 8 == 0);
2645                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN / 8;
2646                 pack_uint32_(track->number, buffer, len);
2647                 if(write_cb(buffer, 1, len, handle) != len)
2648                         return false;
2649
2650                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN % 8 == 0);
2651                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN / 8;
2652                 if(write_cb(track->isrc, 1, len, handle) != len)
2653                         return false;
2654
2655                 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);
2656                 len = (FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN + FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN) / 8;
2657                 memset(buffer, 0, len);
2658                 buffer[0] = (track->type << 7) | (track->pre_emphasis << 6);
2659                 if(write_cb(buffer, 1, len, handle) != len)
2660                         return false;
2661
2662                 FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN % 8 == 0);
2663                 len = FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN / 8;
2664                 pack_uint32_(track->num_indices, buffer, len);
2665                 if(write_cb(buffer, 1, len, handle) != len)
2666                         return false;
2667
2668                 for(j = 0; j < track->num_indices; j++) {
2669                         FLAC__StreamMetadata_CueSheet_Index *index = track->indices + j;
2670
2671                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN % 8 == 0);
2672                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN / 8;
2673                         pack_uint64_(index->offset, buffer, len);
2674                         if(write_cb(buffer, 1, len, handle) != len)
2675                                 return false;
2676
2677                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN % 8 == 0);
2678                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN / 8;
2679                         pack_uint32_(index->number, buffer, len);
2680                         if(write_cb(buffer, 1, len, handle) != len)
2681                                 return false;
2682
2683                         FLAC__ASSERT(FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN % 8 == 0);
2684                         len = FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN / 8;
2685                         memset(buffer, 0, len);
2686                         if(write_cb(buffer, 1, len, handle) != len)
2687                                 return false;
2688                 }
2689         }
2690
2691         return true;
2692 }
2693
2694 FLAC__bool write_metadata_block_data_picture_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Picture *block)
2695 {
2696         unsigned len;
2697         size_t slen;
2698         FLAC__byte buffer[4]; /* magic number is asserted below */
2699
2700         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_TYPE_LEN%8);
2701         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN%8);
2702         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN%8);
2703         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN%8);
2704         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN%8);
2705         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN%8);
2706         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_COLORS_LEN%8);
2707         FLAC__ASSERT(0 == FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN%8);
2708         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8);
2709         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN/8);
2710         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN/8);
2711         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8);
2712         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8);
2713         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8);
2714         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8);
2715         FLAC__ASSERT(sizeof(buffer) >= FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN/8);
2716
2717         len = FLAC__STREAM_METADATA_PICTURE_TYPE_LEN/8;
2718         pack_uint32_(block->type, buffer, len);
2719         if(write_cb(buffer, 1, len, handle) != len)
2720                 return false;
2721
2722         len = FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN/8;
2723         slen = strlen(block->mime_type);
2724         pack_uint32_(slen, buffer, len);
2725         if(write_cb(buffer, 1, len, handle) != len)
2726                 return false;
2727         if(write_cb(block->mime_type, 1, slen, handle) != slen)
2728                 return false;
2729
2730         len = FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN/8;
2731         slen = strlen((const char *)block->description);
2732         pack_uint32_(slen, buffer, len);
2733         if(write_cb(buffer, 1, len, handle) != len)
2734                 return false;
2735         if(write_cb(block->description, 1, slen, handle) != slen)
2736                 return false;
2737
2738         len = FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN/8;
2739         pack_uint32_(block->width, buffer, len);
2740         if(write_cb(buffer, 1, len, handle) != len)
2741                 return false;
2742
2743         len = FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN/8;
2744         pack_uint32_(block->height, buffer, len);
2745         if(write_cb(buffer, 1, len, handle) != len)
2746                 return false;
2747
2748         len = FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN/8;
2749         pack_uint32_(block->depth, buffer, len);
2750         if(write_cb(buffer, 1, len, handle) != len)
2751                 return false;
2752
2753         len = FLAC__STREAM_METADATA_PICTURE_COLORS_LEN/8;
2754         pack_uint32_(block->colors, buffer, len);
2755         if(write_cb(buffer, 1, len, handle) != len)
2756                 return false;
2757
2758         len = FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN/8;
2759         pack_uint32_(block->data_length, buffer, len);
2760         if(write_cb(buffer, 1, len, handle) != len)
2761                 return false;
2762         if(write_cb(block->data, 1, block->data_length, handle) != block->data_length)
2763                 return false;
2764
2765         return true;
2766 }
2767
2768 FLAC__bool write_metadata_block_data_unknown_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Write write_cb, const FLAC__StreamMetadata_Unknown *block, unsigned block_length)
2769 {
2770         if(write_cb(block->data, 1, block_length, handle) != block_length)
2771                 return false;
2772
2773         return true;
2774 }
2775
2776 FLAC__bool write_metadata_block_stationary_(FLAC__Metadata_SimpleIterator *iterator, const FLAC__StreamMetadata *block)
2777 {
2778         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2779                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2780                 return false;
2781         }
2782
2783         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2784                 return false;
2785
2786         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2787                 return false;
2788
2789         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2790                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2791                 return false;
2792         }
2793
2794         return read_metadata_block_header_(iterator);
2795 }
2796
2797 FLAC__bool write_metadata_block_stationary_with_padding_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, unsigned padding_length, FLAC__bool padding_is_last)
2798 {
2799         FLAC__StreamMetadata *padding;
2800
2801         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2802                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2803                 return false;
2804         }
2805
2806         block->is_last = false;
2807
2808         if(!write_metadata_block_header_(iterator->file, &iterator->status, block))
2809                 return false;
2810
2811         if(!write_metadata_block_data_(iterator->file, &iterator->status, block))
2812                 return false;
2813
2814         if(0 == (padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING)))
2815                 return FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
2816
2817         padding->is_last = padding_is_last;
2818         padding->length = padding_length;
2819
2820         if(!write_metadata_block_header_(iterator->file, &iterator->status, padding)) {
2821                 FLAC__metadata_object_delete(padding);
2822                 return false;
2823         }
2824
2825         if(!write_metadata_block_data_(iterator->file, &iterator->status, padding)) {
2826                 FLAC__metadata_object_delete(padding);
2827                 return false;
2828         }
2829
2830         FLAC__metadata_object_delete(padding);
2831
2832         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2833                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2834                 return false;
2835         }
2836
2837         return read_metadata_block_header_(iterator);
2838 }
2839
2840 FLAC__bool rewrite_whole_file_(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool append)
2841 {
2842         FILE *tempfile;
2843         char *tempfilename;
2844         int fixup_is_last_code = 0; /* 0 => no need to change any is_last flags */
2845         off_t fixup_is_last_flag_offset = -1;
2846
2847         FLAC__ASSERT(0 != block || append == false);
2848
2849         if(iterator->is_last) {
2850                 if(append) {
2851                         fixup_is_last_code = 1; /* 1 => clear the is_last flag at the following offset */
2852                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2853                 }
2854                 else if(0 == block) {
2855                         simple_iterator_push_(iterator);
2856                         if(!FLAC__metadata_simple_iterator_prev(iterator)) {
2857                                 (void)simple_iterator_pop_(iterator);
2858                                 return false;
2859                         }
2860                         fixup_is_last_code = -1; /* -1 => set the is_last the flag at the following offset */
2861                         fixup_is_last_flag_offset = iterator->offset[iterator->depth];
2862                         if(!simple_iterator_pop_(iterator))
2863                                 return false;
2864                 }
2865         }
2866
2867         if(!simple_iterator_copy_file_prefix_(iterator, &tempfile, &tempfilename, append))
2868                 return false;
2869
2870         if(0 != block) {
2871                 if(!write_metadata_block_header_(tempfile, &iterator->status, block)) {
2872                         cleanup_tempfile_(&tempfile, &tempfilename);
2873                         return false;
2874                 }
2875
2876                 if(!write_metadata_block_data_(tempfile, &iterator->status, block)) {
2877                         cleanup_tempfile_(&tempfile, &tempfilename);
2878                         return false;
2879                 }
2880         }
2881
2882         if(!simple_iterator_copy_file_postfix_(iterator, &tempfile, &tempfilename, fixup_is_last_code, fixup_is_last_flag_offset, block==0))
2883                 return false;
2884
2885         if(append)
2886                 return FLAC__metadata_simple_iterator_next(iterator);
2887
2888         return true;
2889 }
2890
2891 void simple_iterator_push_(FLAC__Metadata_SimpleIterator *iterator)
2892 {
2893         FLAC__ASSERT(iterator->depth+1 < SIMPLE_ITERATOR_MAX_PUSH_DEPTH);
2894         iterator->offset[iterator->depth+1] = iterator->offset[iterator->depth];
2895         iterator->depth++;
2896 }
2897
2898 FLAC__bool simple_iterator_pop_(FLAC__Metadata_SimpleIterator *iterator)
2899 {
2900         FLAC__ASSERT(iterator->depth > 0);
2901         iterator->depth--;
2902         if(0 != fseeko(iterator->file, iterator->offset[iterator->depth], SEEK_SET)) {
2903                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2904                 return false;
2905         }
2906
2907         return read_metadata_block_header_(iterator);
2908 }
2909
2910 /* return meanings:
2911  * 0: ok
2912  * 1: read error
2913  * 2: seek error
2914  * 3: not a FLAC file
2915  */
2916 unsigned seek_to_first_metadata_block_cb_(FLAC__IOHandle handle, FLAC__IOCallback_Read read_cb, FLAC__IOCallback_Seek seek_cb)
2917 {
2918         FLAC__byte buffer[4];
2919         size_t n;
2920         unsigned i;
2921
2922         FLAC__ASSERT(FLAC__STREAM_SYNC_LENGTH == sizeof(buffer));
2923
2924         /* skip any id3v2 tag */
2925         errno = 0;
2926         n = read_cb(buffer, 1, 4, handle);
2927         if(errno)
2928                 return 1;
2929         else if(n != 4)
2930                 return 3;
2931         else if(0 == memcmp(buffer, "ID3", 3)) {
2932                 unsigned tag_length = 0;
2933
2934                 /* skip to the tag length */
2935                 if(seek_cb(handle, 2, SEEK_CUR) < 0)
2936                         return 2;
2937
2938                 /* read the length */
2939                 for(i = 0; i < 4; i++) {
2940                         if(read_cb(buffer, 1, 1, handle) < 1 || buffer[0] & 0x80)
2941                                 return 1;
2942                         tag_length <<= 7;
2943                         tag_length |= (buffer[0] & 0x7f);
2944                 }
2945
2946                 /* skip the rest of the tag */
2947                 if(seek_cb(handle, tag_length, SEEK_CUR) < 0)
2948                         return 2;
2949
2950                 /* read the stream sync code */
2951                 errno = 0;
2952                 n = read_cb(buffer, 1, 4, handle);
2953                 if(errno)
2954                         return 1;
2955                 else if(n != 4)
2956                         return 3;
2957         }
2958
2959         /* check for the fLaC signature */
2960         if(0 == memcmp(FLAC__STREAM_SYNC_STRING, buffer, FLAC__STREAM_SYNC_LENGTH))
2961                 return 0;
2962         else
2963                 return 3;
2964 }
2965
2966 unsigned seek_to_first_metadata_block_(FILE *f)
2967 {
2968         return seek_to_first_metadata_block_cb_((FLAC__IOHandle)f, (FLAC__IOCallback_Read)fread, fseek_wrapper_);
2969 }
2970
2971 FLAC__bool simple_iterator_copy_file_prefix_(FLAC__Metadata_SimpleIterator *iterator, FILE **tempfile, char **tempfilename, FLAC__bool append)
2972 {
2973         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];
2974
2975         if(0 != fseeko(iterator->file, 0, SEEK_SET)) {
2976                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2977                 return false;
2978         }
2979         if(!open_tempfile_(iterator->filename, iterator->tempfile_path_prefix, tempfile, tempfilename, &iterator->status)) {
2980                 cleanup_tempfile_(tempfile, tempfilename);
2981                 return false;
2982         }
2983         if(!copy_n_bytes_from_file_(iterator->file, *tempfile, offset_end, &iterator->status)) {
2984                 cleanup_tempfile_(tempfile, tempfilename);
2985                 return false;
2986         }
2987
2988         return true;
2989 }
2990
2991 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)
2992 {
2993         off_t save_offset = iterator->offset[iterator->depth];
2994         FLAC__ASSERT(0 != *tempfile);
2995
2996         if(0 != fseeko(iterator->file, save_offset + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length, SEEK_SET)) {
2997                 cleanup_tempfile_(tempfile, tempfilename);
2998                 iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
2999                 return false;
3000         }
3001         if(!copy_remaining_bytes_from_file_(iterator->file, *tempfile, &iterator->status)) {
3002                 cleanup_tempfile_(tempfile, tempfilename);
3003                 return false;
3004         }
3005
3006         if(fixup_is_last_code != 0) {
3007                 /*
3008                  * if code == 1, it means a block was appended to the end so
3009                  *   we have to clear the is_last flag of the previous block
3010                  * if code == -1, it means the last block was deleted so
3011                  *   we have to set the is_last flag of the previous block
3012                  */
3013                 /* MAGIC NUMBERs here; we know the is_last flag is the high bit of the byte at this location */
3014                 FLAC__byte x;
3015                 if(0 != fseeko(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
3016                         cleanup_tempfile_(tempfile, tempfilename);
3017                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3018                         return false;
3019                 }
3020                 if(fread(&x, 1, 1, *tempfile) != 1) {
3021                         cleanup_tempfile_(tempfile, tempfilename);
3022                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3023                         return false;
3024                 }
3025                 if(fixup_is_last_code > 0) {
3026                         FLAC__ASSERT(x & 0x80);
3027                         x &= 0x7f;
3028                 }
3029                 else {
3030                         FLAC__ASSERT(!(x & 0x80));
3031                         x |= 0x80;
3032                 }
3033                 if(0 != fseeko(*tempfile, fixup_is_last_flag_offset, SEEK_SET)) {
3034                         cleanup_tempfile_(tempfile, tempfilename);
3035                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
3036                         return false;
3037                 }
3038                 if(local__fwrite(&x, 1, 1, *tempfile) != 1) {
3039                         cleanup_tempfile_(tempfile, tempfilename);
3040                         iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3041                         return false;
3042                 }
3043         }
3044
3045         (void)fclose(iterator->file);
3046
3047         if(!transport_tempfile_(iterator->filename, tempfile, tempfilename, &iterator->status))
3048                 return false;
3049
3050         if(iterator->has_stats)
3051                 set_file_stats_(iterator->filename, &iterator->stats);
3052
3053         if(!simple_iterator_prime_input_(iterator, !iterator->is_writable))
3054                 return false;
3055         if(backup) {
3056                 while(iterator->offset[iterator->depth] + (off_t)FLAC__STREAM_METADATA_HEADER_LENGTH + (off_t)iterator->length < save_offset)
3057                         if(!FLAC__metadata_simple_iterator_next(iterator))
3058                                 return false;
3059                 return true;
3060         }
3061         else {
3062                 /* move the iterator to it's original block faster by faking a push, then doing a pop_ */
3063                 FLAC__ASSERT(iterator->depth == 0);
3064                 iterator->offset[0] = save_offset;
3065                 iterator->depth++;
3066                 return simple_iterator_pop_(iterator);
3067         }
3068 }
3069
3070 FLAC__bool copy_n_bytes_from_file_(FILE *file, FILE *tempfile, off_t bytes, FLAC__Metadata_SimpleIteratorStatus *status)
3071 {
3072         FLAC__byte buffer[8192];
3073         size_t n;
3074
3075         FLAC__ASSERT(bytes >= 0);
3076         while(bytes > 0) {
3077                 n = min(sizeof(buffer), (size_t)bytes);
3078                 if(fread(buffer, 1, n, file) != n) {
3079                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3080                         return false;
3081                 }
3082                 if(local__fwrite(buffer, 1, n, tempfile) != n) {
3083                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3084                         return false;
3085                 }
3086                 bytes -= n;
3087         }
3088
3089         return true;
3090 }
3091
3092 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)
3093 {
3094         FLAC__byte buffer[8192];
3095         size_t n;
3096
3097         FLAC__ASSERT(bytes >= 0);
3098         while(bytes > 0) {
3099                 n = min(sizeof(buffer), (size_t)bytes);
3100                 if(read_cb(buffer, 1, n, handle) != n) {
3101                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3102                         return false;
3103                 }
3104                 if(temp_write_cb(buffer, 1, n, temp_handle) != n) {
3105                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3106                         return false;
3107                 }
3108                 bytes -= n;
3109         }
3110
3111         return true;
3112 }
3113
3114 FLAC__bool copy_remaining_bytes_from_file_(FILE *file, FILE *tempfile, FLAC__Metadata_SimpleIteratorStatus *status)
3115 {
3116         FLAC__byte buffer[8192];
3117         size_t n;
3118
3119         while(!feof(file)) {
3120                 n = fread(buffer, 1, sizeof(buffer), file);
3121                 if(n == 0 && !feof(file)) {
3122                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3123                         return false;
3124                 }
3125                 if(n > 0 && local__fwrite(buffer, 1, n, tempfile) != n) {
3126                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3127                         return false;
3128                 }
3129         }
3130
3131         return true;
3132 }
3133
3134 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)
3135 {
3136         FLAC__byte buffer[8192];
3137         size_t n;
3138
3139         while(!eof_cb(handle)) {
3140                 n = read_cb(buffer, 1, sizeof(buffer), handle);
3141                 if(n == 0 && !eof_cb(handle)) {
3142                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR;
3143                         return false;
3144                 }
3145                 if(n > 0 && temp_write_cb(buffer, 1, n, temp_handle) != n) {
3146                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR;
3147                         return false;
3148                 }
3149         }
3150
3151         return true;
3152 }
3153
3154 FLAC__bool open_tempfile_(const char *filename, const char *tempfile_path_prefix, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
3155 {
3156         static const char *tempfile_suffix = ".metadata_edit";
3157         if(0 == tempfile_path_prefix) {
3158                 if(0 == (*tempfilename = (char*)malloc(strlen(filename) + strlen(tempfile_suffix) + 1))) {
3159                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
3160                         return false;
3161                 }
3162                 strcpy(*tempfilename, filename);
3163                 strcat(*tempfilename, tempfile_suffix);
3164         }
3165         else {
3166                 const char *p = strrchr(filename, '/');
3167                 if(0 == p)
3168                         p = filename;
3169                 else
3170                         p++;
3171
3172                 if(0 == (*tempfilename = (char*)malloc(strlen(tempfile_path_prefix) + 1 + strlen(p) + strlen(tempfile_suffix) + 1))) {
3173                         *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
3174                         return false;
3175                 }
3176                 strcpy(*tempfilename, tempfile_path_prefix);
3177                 strcat(*tempfilename, "/");
3178                 strcat(*tempfilename, p);
3179                 strcat(*tempfilename, tempfile_suffix);
3180         }
3181
3182         if(0 == (*tempfile = fopen(*tempfilename, "w+b"))) {
3183                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE;
3184                 return false;
3185         }
3186
3187         return true;
3188 }
3189
3190 FLAC__bool transport_tempfile_(const char *filename, FILE **tempfile, char **tempfilename, FLAC__Metadata_SimpleIteratorStatus *status)
3191 {
3192         FLAC__ASSERT(0 != filename);
3193         FLAC__ASSERT(0 != tempfile);
3194         FLAC__ASSERT(0 != *tempfile);
3195         FLAC__ASSERT(0 != tempfilename);
3196         FLAC__ASSERT(0 != *tempfilename);
3197         FLAC__ASSERT(0 != status);
3198
3199         (void)fclose(*tempfile);
3200         *tempfile = 0;
3201
3202 #if defined _MSC_VER || defined __BORLANDC__ || defined __MINGW32__ || defined __EMX__
3203         /* on some flavors of windows, rename() will fail if the destination already exists */
3204         if(unlink(filename) < 0) {
3205                 cleanup_tempfile_(tempfile, tempfilename);
3206                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR;
3207                 return false;
3208         }
3209 #endif
3210
3211         /*@@@ to fully support the tempfile_path_prefix we need to update this piece to actually copy across filesystems instead of just rename(): */
3212         if(0 != rename(*tempfilename, filename)) {
3213                 cleanup_tempfile_(tempfile, tempfilename);
3214                 *status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR;
3215                 return false;
3216         }
3217
3218         cleanup_tempfile_(tempfile, tempfilename);
3219
3220         return true;
3221 }
3222
3223 void cleanup_tempfile_(FILE **tempfile, char **tempfilename)
3224 {
3225         if(0 != *tempfile) {
3226                 (void)fclose(*tempfile);
3227                 *tempfile = 0;
3228         }
3229
3230         if(0 != *tempfilename) {
3231                 (void)unlink(*tempfilename);
3232                 free(*tempfilename);
3233                 *tempfilename = 0;
3234         }
3235 }
3236
3237 FLAC__bool get_file_stats_(const char *filename, struct stat *stats)
3238 {
3239         FLAC__ASSERT(0 != filename);
3240         FLAC__ASSERT(0 != stats);
3241         return (0 == stat(filename, stats));
3242 }
3243
3244 void set_file_stats_(const char *filename, struct stat *stats)
3245 {
3246         struct utimbuf srctime;
3247
3248         FLAC__ASSERT(0 != filename);
3249         FLAC__ASSERT(0 != stats);
3250
3251         srctime.actime = stats->st_atime;
3252         srctime.modtime = stats->st_mtime;
3253         (void)chmod(filename, stats->st_mode);
3254         (void)utime(filename, &srctime);
3255 #if !defined _MSC_VER && !defined __BORLANDC__ && !defined __MINGW32__ && !defined __EMX__
3256         (void)chown(filename, stats->st_uid, -1);
3257         (void)chown(filename, -1, stats->st_gid);
3258 #endif
3259 }
3260
3261 int fseek_wrapper_(FLAC__IOHandle handle, FLAC__int64 offset, int whence)
3262 {
3263         return fseeko((FILE*)handle, (off_t)offset, whence);
3264 }
3265
3266 FLAC__int64 ftell_wrapper_(FLAC__IOHandle handle)
3267 {
3268         return ftello((FILE*)handle);
3269 }
3270
3271 FLAC__Metadata_ChainStatus get_equivalent_status_(FLAC__Metadata_SimpleIteratorStatus status)
3272 {
3273         switch(status) {
3274                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK:
3275                         return FLAC__METADATA_CHAIN_STATUS_OK;
3276                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT:
3277                         return FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT;
3278                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE:
3279                         return FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE;
3280                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE:
3281                         return FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE;
3282                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE:
3283                         return FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE;
3284                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA:
3285                         return FLAC__METADATA_CHAIN_STATUS_BAD_METADATA;
3286                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR:
3287                         return FLAC__METADATA_CHAIN_STATUS_READ_ERROR;
3288                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR:
3289                         return FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR;
3290                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR:
3291                         return FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR;
3292                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR:
3293                         return FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR;
3294                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR:
3295                         return FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR;
3296                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR:
3297                         return FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR;
3298                 case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR:
3299                 default:
3300                         return FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR;
3301         }
3302 }