Function rans_decode_symbol

nodedb-codec/src/rans.rs:237–250

(
    state: u32,
    lookup: &[u8; PROB_SCALE as usize],
    cum_freqs: &[u32; 257],
    sym_freqs: &[u32; 256],
)

}

fn rans_decode_symbol(
    state: u32,
    lookup: &[u8; PROB_SCALE as usize],
    cum_freqs: &[u32; 257],
    sym_freqs: &[u32; 256],
) -> (u8, u32) {
    let slot = state & (PROB_SCALE - 1);
    let sym = lookup[slot as usize];
    let start = cum_freqs[sym as usize];
    let freq = sym_freqs[sym as usize];

    let new_state = freq * (state >> PROB_BITS) + slot - start;
    (sym, new_state)
}

fn rans_decode_renorm(mut state: u32, stream: &[u8], pos: &mut usize) -> u32 {
    while state < RANS_L && *pos > 0 {