Type Definition flac_sys::FLAC__StreamDecoderLengthCallback

type FLAC__StreamDecoderLengthCallback = Option<unsafe extern "C" fn(decoder: *const FLAC__StreamDecoder, stream_length: *mut FLAC__uint64, client_data: *mut c_void) -> FLAC__StreamDecoderLengthStatus>;

Signature for the length callback.

A function pointer matching this signature may be passed to FLAC__stream_decoder_init*_stream(). The supplied function will be called when the decoder wants to know the total length of the stream in bytes.

Here is an example of a length callback for stdio streams: \code FLAC__StreamDecoderLengthStatus length_cb(const FLAC__StreamDecoder *decoder, FLAC__uint64 *stream_length, void *client_data) { FILE file = ((MyClientData)client_data)->file; struct stat filestats;

if(file == stdin) return FLAC__STREAM_DECODER_LENGTH_STATUS_UNSUPPORTED; else if(fstat(fileno(file), &filestats) != 0) return FLAC__STREAM_DECODER_LENGTH_STATUS_ERROR; else { *stream_length = (FLAC__uint64)filestats.st_size; return FLAC__STREAM_DECODER_LENGTH_STATUS_OK; } } \endcode

\note In general, FLAC__StreamDecoder functions which change the state should not be called on the \a decoder while in the callback.

\param decoder The decoder instance calling the callback. \param stream_length A pointer to storage for the length of the stream in bytes. \param client_data The callee's client data set through FLAC__stream_decoder_init_*(). \retval FLAC__StreamDecoderLengthStatus The callee's return status.