Constant esp_idf_hal::sys::RingbufferType_t_RINGBUF_TYPE_BYTEBUF

pub const RingbufferType_t_RINGBUF_TYPE_BYTEBUF: u32 = 2; // 2u32

Byte buffers store data as a sequence of bytes and do not maintain separate items, therefore byte buffers have no overhead. All data is stored as a sequence of byte and any number of bytes can be sent or retrieved each time.