file_decoder.c

在x86平台上运行不可信任代码的sandbox。

{
	FLAC__ASSERT(0 != decoder);
	FLAC__ASSERT(0 != decoder->private_);
	FLAC__ASSERT(0 != decoder->protected_);
	FLAC__ASSERT(0 != decoder->private_->seekable_stream_decoder);
	if(decoder->protected_->state != FLAC__FILE_DECODER_UNINITIALIZED)
		return false;
	return FLAC__seekable_stream_decoder_set_metadata_ignore(decoder->private_->seekable_stream_decoder, type);
}

FLAC_API FLAC__bool FLAC__file_decoder_set_metadata_ignore_application(FLAC__FileDecoder *decoder, const FLAC__byte id[4])
{
	FLAC__ASSERT(0 != decoder);
	FLAC__ASSERT(0 != decoder->private_);
	FLAC__ASSERT(0 != decoder->protected_);
	FLAC__ASSERT(0 != decoder->private_->seekable_stream_decoder);
	if(decoder->protected_->state != FLAC__FILE_DECODER_UNINITIALIZED)
		return false;
	return FLAC__seekable_stream_decoder_set_metadata_ignore_application(decoder->private_->seekable_stream_decoder, id);
}

FLAC_API FLAC__bool FLAC__file_decoder_set_metadata_ignore_all(FLAC__FileDecoder *decoder)
{
	FLAC__ASSERT(0 != decoder);
	FLAC__ASSERT(0 != decoder->private_);
	FLAC__ASSERT(0 != decoder->protected_);
	FLAC__ASSERT(0 != decoder->private_->seekable_stream_decoder);
	if(decoder->protected_->state != FLAC__FILE_DECODER_UNINITIALIZED)
		return false;
	return FLAC__seekable_stream_decoder_set_metadata_ignore_all(decoder->private_->seekable_stream_decoder);
}

FLAC_API FLAC__FileDecoderState FLAC__file_decoder_get_state(const FLAC__FileDecoder *decoder)
{
	FLAC__ASSERT(0 != decoder);
	FLAC__ASSERT(0 != decoder->protected_);
	return decoder->protected_->state;
}

FLAC_API FLAC__SeekableStreamDecoderState FLAC__file_decoder_get_seekable_stream_decoder_state(const FLAC__FileDecoder *decoder)
{
	FLAC__ASSERT(0 != decoder);
	FLAC__ASSERT(0 != decoder->private_);
	return FLAC__seekable_stream_decoder_get_state(decoder->private_->seekable_stream_decoder);
}

FLAC_API FLAC__StreamDecoderState FLAC__file_decoder_get_stream_decoder_state(const FLAC__FileDecoder *decoder)
{
	FLAC__ASSERT(0 != decoder);
	FLAC__ASSERT(0 != decoder->private_);
	return FLAC__seekable_stream_decoder_get_stream_decoder_state(decoder->private_->seekable_stream_decoder);
}

FLAC_API const char *FLAC__file_decoder_get_resolved_state_string(const FLAC__FileDecoder *decoder)
{
	if(decoder->protected_->state != FLAC__FILE_DECODER_SEEKABLE_STREAM_DECODER_ERROR)
		return FLAC__FileDecoderStateString[decoder->protected_->state];
	else
		return FLAC__seekable_stream_decoder_get_resolved_state_string(decoder->private_->seekable_stream_decoder);
}

FLAC_API FLAC__bool FLAC__file_decoder_get_md5_checking(const FLAC__FileDecoder *decoder)
{
	FLAC__ASSERT(0 != decoder);
	FLAC__ASSERT(0 != decoder->private_);
	return FLAC__seekable_stream_decoder_get_md5_checking(decoder->private_->seekable_stream_decoder);
}

FLAC_API unsigned FLAC__file_decoder_get_channels(const FLAC__FileDecoder *decoder)
{
	FLAC__ASSERT(0 != decoder);
	FLAC__ASSERT(0 != decoder->private_);
	return FLAC__seekable_stream_decoder_get_channels(decoder->private_->seekable_stream_decoder);
}

FLAC_API FLAC__ChannelAssignment FLAC__file_decoder_get_channel_assignment(const FLAC__FileDecoder *decoder)
{
	FLAC__ASSERT(0 != decoder);
	FLAC__ASSERT(0 != decoder->private_);
	return FLAC__seekable_stream_decoder_get_channel_assignment(decoder->private_->seekable_stream_decoder);
}

FLAC_API unsigned FLAC__file_decoder_get_bits_per_sample(const FLAC__FileDecoder *decoder)
{
	FLAC__ASSERT(0 != decoder);
	FLAC__ASSERT(0 != decoder->private_);
	return FLAC__seekable_stream_decoder_get_bits_per_sample(decoder->private_->seekable_stream_decoder);
}

FLAC_API unsigned FLAC__file_decoder_get_sample_rate(const FLAC__FileDecoder *decoder)
{
	FLAC__ASSERT(0 != decoder);
	FLAC__ASSERT(0 != decoder->private_);
	return FLAC__seekable_stream_decoder_get_sample_rate(decoder->private_->seekable_stream_decoder);
}

FLAC_API unsigned FLAC__file_decoder_get_blocksize(const FLAC__FileDecoder *decoder)
{
	FLAC__ASSERT(0 != decoder);
	FLAC__ASSERT(0 != decoder->private_);
	return FLAC__seekable_stream_decoder_get_blocksize(decoder->private_->seekable_stream_decoder);
}

FLAC_API FLAC__bool FLAC__file_decoder_get_decode_position(const FLAC__FileDecoder *decoder, FLAC__uint64 *position)
{
	FLAC__ASSERT(0 != decoder);
	FLAC__ASSERT(0 != decoder->private_);
	return FLAC__seekable_stream_decoder_get_decode_position(decoder->private_->seekable_stream_decoder, position);
}

FLAC_API FLAC__bool FLAC__file_decoder_process_single(FLAC__FileDecoder *decoder)
{
	FLAC__bool ret;
	FLAC__ASSERT(0 != decoder);

	if(decoder->private_->seekable_stream_decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM)
		decoder->protected_->state = FLAC__FILE_DECODER_END_OF_FILE;

	if(decoder->protected_->state == FLAC__FILE_DECODER_END_OF_FILE)
		return true;

	FLAC__ASSERT(decoder->protected_->state == FLAC__FILE_DECODER_OK);

	ret = FLAC__seekable_stream_decoder_process_single(decoder->private_->seekable_stream_decoder);
	if(!ret)
		decoder->protected_->state = FLAC__FILE_DECODER_SEEKABLE_STREAM_DECODER_ERROR;

	return ret;
}

FLAC_API FLAC__bool FLAC__file_decoder_process_until_end_of_metadata(FLAC__FileDecoder *decoder)
{
	FLAC__bool ret;
	FLAC__ASSERT(0 != decoder);

	if(decoder->private_->seekable_stream_decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM)
		decoder->protected_->state = FLAC__FILE_DECODER_END_OF_FILE;

	if(decoder->protected_->state == FLAC__FILE_DECODER_END_OF_FILE)
		return true;

	FLAC__ASSERT(decoder->protected_->state == FLAC__FILE_DECODER_OK);

	ret = FLAC__seekable_stream_decoder_process_until_end_of_metadata(decoder->private_->seekable_stream_decoder);
	if(!ret)
		decoder->protected_->state = FLAC__FILE_DECODER_SEEKABLE_STREAM_DECODER_ERROR;

	return ret;
}

FLAC_API FLAC__bool FLAC__file_decoder_process_until_end_of_file(FLAC__FileDecoder *decoder)
{
	FLAC__bool ret;
	FLAC__ASSERT(0 != decoder);

	if(decoder->private_->seekable_stream_decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM)
		decoder->protected_->state = FLAC__FILE_DECODER_END_OF_FILE;

	if(decoder->protected_->state == FLAC__FILE_DECODER_END_OF_FILE)
		return true;

	FLAC__ASSERT(decoder->protected_->state == FLAC__FILE_DECODER_OK);

	ret = FLAC__seekable_stream_decoder_process_until_end_of_stream(decoder->private_->seekable_stream_decoder);
	if(!ret)
		decoder->protected_->state = FLAC__FILE_DECODER_SEEKABLE_STREAM_DECODER_ERROR;

	return ret;
}

FLAC_API FLAC__bool FLAC__file_decoder_skip_single_frame(FLAC__FileDecoder *decoder)
{
	FLAC__bool ret;
	FLAC__ASSERT(0 != decoder);

	if(decoder->private_->seekable_stream_decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM)
		decoder->protected_->state = FLAC__FILE_DECODER_END_OF_FILE;

	if(decoder->protected_->state == FLAC__FILE_DECODER_END_OF_FILE)
		return true;

	FLAC__ASSERT(decoder->protected_->state == FLAC__FILE_DECODER_OK);

	ret = FLAC__seekable_stream_decoder_skip_single_frame(decoder->private_->seekable_stream_decoder);
	if(!ret)
		decoder->protected_->state = FLAC__FILE_DECODER_SEEKABLE_STREAM_DECODER_ERROR;

	return ret;
}

FLAC_API FLAC__bool FLAC__file_decoder_seek_absolute(FLAC__FileDecoder *decoder, FLAC__uint64 sample)
{
	FLAC__ASSERT(0 != decoder);
	FLAC__ASSERT(decoder->protected_->state == FLAC__FILE_DECODER_OK || decoder->protected_->state == FLAC__FILE_DECODER_END_OF_FILE);

	if(decoder->private_->filename == 0) { /* means the file is stdin... */
		decoder->protected_->state = FLAC__FILE_DECODER_SEEK_ERROR;
		return false;
	}

	if(!FLAC__seekable_stream_decoder_seek_absolute(decoder->private_->seekable_stream_decoder, sample)) {
		decoder->protected_->state = FLAC__FILE_DECODER_SEEK_ERROR;
		return false;
	}
	else {
		decoder->protected_->state = FLAC__FILE_DECODER_OK;
		return true;
	}
}


/***********************************************************************
 *
 * Private class methods
 *
 ***********************************************************************/

void set_defaults_(FLAC__FileDecoder *decoder)
{
	FLAC__ASSERT(0 != decoder);
	FLAC__ASSERT(0 != decoder->private_);

	decoder->private_->filename = 0;
	decoder->private_->write_callback = 0;
	decoder->private_->metadata_callback = 0;
	decoder->private_->error_callback = 0;
	decoder->private_->client_data = 0;
}

/*
 * This will forcibly set stdin to binary mode (for OSes that require it)
 */
FILE *get_binary_stdin_()
{
	/* if something breaks here it is probably due to the presence or
	 * absence of an underscore before the identifiers 'setmode',
	 * 'fileno', and/or 'O_BINARY'; check your system header files.
	 */
#if defined _MSC_VER || defined __MINGW32__
	_setmode(_fileno(stdin), _O_BINARY);
#elif defined __CYGWIN__
	/* almost certainly not needed for any modern Cygwin, but let's be safe... */
	setmode(_fileno(stdin), _O_BINARY);
#endif

	return stdin;
}

FLAC__SeekableStreamDecoderReadStatus read_callback_(const FLAC__SeekableStreamDecoder *decoder, FLAC__byte buffer[], unsigned *bytes, void *client_data)
{
	FLAC__FileDecoder *file_decoder = (FLAC__FileDecoder *)client_data;
	(void)decoder;

	if(*bytes > 0) {
		*bytes = (unsigned)fread(buffer, sizeof(FLAC__byte), *bytes, file_decoder->private_->file);
		if(ferror(file_decoder->private_->file)) {
			return FLAC__SEEKABLE_STREAM_DECODER_READ_STATUS_ERROR;
		}
		else {
			return FLAC__SEEKABLE_STREAM_DECODER_READ_STATUS_OK;
		}
	}
	else
		return FLAC__SEEKABLE_STREAM_DECODER_READ_STATUS_ERROR; /* abort to avoid a deadlock */
}

FLAC__SeekableStreamDecoderSeekStatus seek_callback_(const FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 absolute_byte_offset, void *client_data)
{
	FLAC__FileDecoder *file_decoder = (FLAC__FileDecoder *)client_data;
	(void)decoder;

	if(fseek(file_decoder->private_->file, (long)absolute_byte_offset, SEEK_SET) < 0)
		return FLAC__SEEKABLE_STREAM_DECODER_SEEK_STATUS_ERROR;
	else
		return FLAC__SEEKABLE_STREAM_DECODER_SEEK_STATUS_OK;
}

FLAC__SeekableStreamDecoderTellStatus tell_callback_(const FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 *absolute_byte_offset, void *client_data)
{
	FLAC__FileDecoder *file_decoder = (FLAC__FileDecoder *)client_data;
	long pos;
	(void)decoder;

	if((pos = ftell(file_decoder->private_->file)) < 0)
		return FLAC__SEEKABLE_STREAM_DECODER_TELL_STATUS_ERROR;
	else {
		*absolute_byte_offset = (FLAC__uint64)pos;
		return FLAC__SEEKABLE_STREAM_DECODER_TELL_STATUS_OK;
	}
}

FLAC__SeekableStreamDecoderLengthStatus length_callback_(const FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 *stream_length, void *client_data)
{
	FLAC__FileDecoder *file_decoder = (FLAC__FileDecoder *)client_data;
	struct stat filestats;
	(void)decoder;

	if(0 == file_decoder->private_->filename || stat(file_decoder->private_->filename, &filestats) != 0)
		return FLAC__SEEKABLE_STREAM_DECODER_LENGTH_STATUS_ERROR;
	else {
		*stream_length = (FLAC__uint64)filestats.st_size;
		return FLAC__SEEKABLE_STREAM_DECODER_LENGTH_STATUS_OK;
	}
}

FLAC__bool eof_callback_(const FLAC__SeekableStreamDecoder *decoder, void *client_data)
{
	FLAC__FileDecoder *file_decoder = (FLAC__FileDecoder *)client_data;
	(void)decoder;

	return feof(file_decoder->private_->file)? true : false;
}

FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__SeekableStreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
{
	FLAC__FileDecoder *file_decoder = (FLAC__FileDecoder *)client_data;
	(void)decoder;

	return file_decoder->private_->write_callback(file_decoder, frame, buffer, file_decoder->private_->client_data);
}

void metadata_callback_(const FLAC__SeekableStreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
{
	FLAC__FileDecoder *file_decoder = (FLAC__FileDecoder *)client_data;
	(void)decoder;

	file_decoder->private_->metadata_callback(file_decoder, metadata, file_decoder->private_->client_data);
}

void error_callback_(const FLAC__SeekableStreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
{
	FLAC__FileDecoder *file_decoder = (FLAC__FileDecoder *)client_data;
	(void)decoder;

	file_decoder->private_->error_callback(file_decoder, status, file_decoder->private_->client_data);
}