📄 metadata_iterators.c
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FLAC_API FLAC__MetadataType FLAC__metadata_simple_iterator_get_block_type(const FLAC__Metadata_SimpleIterator *iterator)
{
FLAC__ASSERT(0 != iterator);
FLAC__ASSERT(0 != iterator->file);
return iterator->type;
}
FLAC_API FLAC__StreamMetadata *FLAC__metadata_simple_iterator_get_block(FLAC__Metadata_SimpleIterator *iterator)
{
FLAC__StreamMetadata *block = FLAC__metadata_object_new(iterator->type);
FLAC__ASSERT(0 != iterator);
FLAC__ASSERT(0 != iterator->file);
if(0 != block) {
block->is_last = iterator->is_last;
block->length = iterator->length;
if(!read_metadata_block_data_(iterator, block)) {
FLAC__metadata_object_delete(block);
return 0;
}
/* back up to the beginning of the block data to stay consistent */
if(0 != fseek(iterator->file, iterator->offset[iterator->depth] + FLAC__STREAM_METADATA_HEADER_LENGTH, SEEK_SET)) {
iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR;
FLAC__metadata_object_delete(block);
return 0;
}
}
else
iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
return block;
}
FLAC_API FLAC__bool FLAC__metadata_simple_iterator_set_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding)
{
FLAC__ASSERT_DECLARATION(long debug_target_offset = iterator->offset[iterator->depth];)
FLAC__bool ret;
FLAC__ASSERT(0 != iterator);
FLAC__ASSERT(0 != iterator->file);
FLAC__ASSERT(0 != block);
if(!iterator->is_writable) {
iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE;
return false;
}
if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO || block->type == FLAC__METADATA_TYPE_STREAMINFO) {
if(iterator->type != block->type) {
iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
return false;
}
}
block->is_last = iterator->is_last;
if(iterator->length == block->length)
return write_metadata_block_stationary_(iterator, block);
else if(iterator->length > block->length) {
if(use_padding && iterator->length >= FLAC__STREAM_METADATA_HEADER_LENGTH + block->length) {
ret = write_metadata_block_stationary_with_padding_(iterator, block, iterator->length - FLAC__STREAM_METADATA_HEADER_LENGTH - block->length, block->is_last);
FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
FLAC__ASSERT(!ret || ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
return ret;
}
else {
ret = rewrite_whole_file_(iterator, block, /*append=*/false);
FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
FLAC__ASSERT(!ret || ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
return ret;
}
}
else /* iterator->length < block->length */ {
unsigned padding_leftover = 0;
FLAC__bool padding_is_last = false;
if(use_padding) {
/* first see if we can even use padding */
if(iterator->is_last) {
use_padding = false;
}
else {
const unsigned extra_padding_bytes_required = block->length - iterator->length;
simple_iterator_push_(iterator);
if(!FLAC__metadata_simple_iterator_next(iterator)) {
(void)simple_iterator_pop_(iterator);
return false;
}
if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
use_padding = false;
}
else {
if(FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length == extra_padding_bytes_required) {
padding_leftover = 0;
block->is_last = iterator->is_last;
}
else if(iterator->length < extra_padding_bytes_required)
use_padding = false;
else {
padding_leftover = FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length - extra_padding_bytes_required;
padding_is_last = iterator->is_last;
block->is_last = false;
}
}
if(!simple_iterator_pop_(iterator))
return false;
}
}
if(use_padding) {
if(padding_leftover == 0) {
ret = write_metadata_block_stationary_(iterator, block);
FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
FLAC__ASSERT(!ret || ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
return ret;
}
else {
FLAC__ASSERT(padding_leftover >= FLAC__STREAM_METADATA_HEADER_LENGTH);
ret = write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover - FLAC__STREAM_METADATA_HEADER_LENGTH, padding_is_last);
FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
FLAC__ASSERT(!ret || ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
return ret;
}
}
else {
ret = rewrite_whole_file_(iterator, block, /*append=*/false);
FLAC__ASSERT(!ret || iterator->offset[iterator->depth] == debug_target_offset);
FLAC__ASSERT(!ret || ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
return ret;
}
}
}
FLAC_API FLAC__bool FLAC__metadata_simple_iterator_insert_block_after(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding)
{
unsigned padding_leftover = 0;
FLAC__bool padding_is_last = false;
FLAC__ASSERT_DECLARATION(long debug_target_offset = iterator->offset[iterator->depth] + FLAC__STREAM_METADATA_HEADER_LENGTH + iterator->length;)
FLAC__bool ret;
FLAC__ASSERT(0 != iterator);
FLAC__ASSERT(0 != iterator->file);
FLAC__ASSERT(0 != block);
if(!iterator->is_writable)
return false;
if(block->type == FLAC__METADATA_TYPE_STREAMINFO) {
iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
return false;
}
block->is_last = iterator->is_last;
if(use_padding) {
/* first see if we can even use padding */
if(iterator->is_last) {
use_padding = false;
}
else {
simple_iterator_push_(iterator);
if(!FLAC__metadata_simple_iterator_next(iterator)) {
(void)simple_iterator_pop_(iterator);
return false;
}
if(iterator->type != FLAC__METADATA_TYPE_PADDING) {
use_padding = false;
}
else {
if(iterator->length == block->length) {
padding_leftover = 0;
block->is_last = iterator->is_last;
}
else if(iterator->length < FLAC__STREAM_METADATA_HEADER_LENGTH + block->length)
use_padding = false;
else {
padding_leftover = iterator->length - block->length;
padding_is_last = iterator->is_last;
block->is_last = false;
}
}
if(!simple_iterator_pop_(iterator))
return false;
}
}
if(use_padding) {
/* move to the next block, which is suitable padding */
if(!FLAC__metadata_simple_iterator_next(iterator))
return false;
if(padding_leftover == 0) {
ret = write_metadata_block_stationary_(iterator, block);
FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
FLAC__ASSERT(ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
return ret;
}
else {
FLAC__ASSERT(padding_leftover >= FLAC__STREAM_METADATA_HEADER_LENGTH);
ret = write_metadata_block_stationary_with_padding_(iterator, block, padding_leftover - FLAC__STREAM_METADATA_HEADER_LENGTH, padding_is_last);
FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
FLAC__ASSERT(ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
return ret;
}
}
else {
ret = rewrite_whole_file_(iterator, block, /*append=*/true);
FLAC__ASSERT(iterator->offset[iterator->depth] == debug_target_offset);
FLAC__ASSERT(ftell(iterator->file) == debug_target_offset + (long)FLAC__STREAM_METADATA_HEADER_LENGTH);
return ret;
}
}
FLAC_API FLAC__bool FLAC__metadata_simple_iterator_delete_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool use_padding)
{
FLAC__ASSERT_DECLARATION(long debug_target_offset = iterator->offset[iterator->depth];)
FLAC__bool ret;
if(iterator->type == FLAC__METADATA_TYPE_STREAMINFO) {
iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT;
return false;
}
if(use_padding) {
FLAC__StreamMetadata *padding = FLAC__metadata_object_new(FLAC__METADATA_TYPE_PADDING);
if(0 == padding) {
iterator->status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR;
return false;
}
padding->length = iterator->length;
if(!FLAC__metadata_simple_iterator_set_block(iterator, padding, false)) {
FLAC__metadata_object_delete(padding);
return false;
}
FLAC__metadata_object_delete(padding);
if(!FLAC__metadata_simple_iterator_prev(iterator))
return false;
FLAC__ASSERT(iterator->offset[iterator->depth] + (long)FLAC__STREAM_METADATA_HEADER_LENGTH + (long)iterator->length == debug_target_offset);
FLAC__ASSERT(ftell(iterator->file) + (long)iterator->length == debug_target_offset);
return true;
}
else {
ret = rewrite_whole_file_(iterator, 0, /*append=*/false);
FLAC__ASSERT(iterator->offset[iterator->depth] + (long)FLAC__STREAM_METADATA_HEADER_LENGTH + (long)iterator->length == debug_target_offset);
FLAC__ASSERT(ftell(iterator->file) + (long)iterator->length == debug_target_offset);
return ret;
}
}
/****************************************************************************
*
* Level 2 implementation
*
***************************************************************************/
typedef struct FLAC__Metadata_Node {
FLAC__StreamMetadata *data;
struct FLAC__Metadata_Node *prev, *next;
} FLAC__Metadata_Node;
struct FLAC__Metadata_Chain {
char *filename; /* will be NULL if using callbacks */
FLAC__Metadata_Node *head;
FLAC__Metadata_Node *tail;
unsigned nodes;
FLAC__Metadata_ChainStatus status;
long first_offset, last_offset; /*@@@ 2G limit */
/*
* This is the length of the chain initially read from the FLAC file.
* it is used to compare against the current length to decide whether
* or not the whole file has to be rewritten.
*/
unsigned initial_length; /*@@@ 4G limit */
};
struct FLAC__Metadata_Iterator {
FLAC__Metadata_Chain *chain;
FLAC__Metadata_Node *current;
};
FLAC_API const char * const FLAC__Metadata_ChainStatusString[] = {
"FLAC__METADATA_CHAIN_STATUS_OK",
"FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT",
"FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE",
"FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE",
"FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE",
"FLAC__METADATA_CHAIN_STATUS_BAD_METADATA",
"FLAC__METADATA_CHAIN_STATUS_READ_ERROR",
"FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR",
"FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR",
"FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR",
"FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR",
"FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR",
"FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR",
"FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS",
"FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH",
"FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL"
};
static FLAC__Metadata_Node *node_new_()
{
return (FLAC__Metadata_Node*)calloc(1, sizeof(FLAC__Metadata_Node));
}
static void node_delete_(FLAC__Metadata_Node *node)
{
FLAC__ASSERT(0 != node);
if(0 != node->data)
FLAC__metadata_object_delete(node->data);
free(node);
}
static void chain_init_(FLAC__Metadata_Chain *chain)
{
FLAC__ASSERT(0 != chain);
chain->filename = 0;
chain->head = chain->tail = 0;
chain->nodes = 0;
chain->status = FLAC__METADATA_CHAIN_STATUS_OK;
chain->initial_length = 0;
}
static void chain_clear_(FLAC__Metadata_Chain *chain)
{
FLAC__Metadata_Node *node, *next;
FLAC__ASSERT(0 != chain);
for(node = chain->head; node; ) {
next = node->next;
node_delete_(node);
node = next;
}
if(0 != chain->filename)
free(chain->filename);
chain_init_(chain);
}
static void chain_append_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
{
FLAC__ASSERT(0 != chain);
FLAC__ASSERT(0 != node);
FLAC__ASSERT(0 != node->data);
node->next = node->prev = 0;
node->data->is_last = true;
if(0 != chain->tail)
chain->tail->data->is_last = false;
if(0 == chain->head)
chain->head = node;
else {
FLAC__ASSERT(0 != chain->tail);
chain->tail->next = node;
node->prev = chain->tail;
}
chain->tail = node;
chain->nodes++;
}
static void chain_remove_node_(FLAC__Metadata_Chain *chain, FLAC__Metadata_Node *node)
{
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