Function base64::engine::general_purpose::decode::decode_chunk

fn decode_chunk(
    input: &[u8],
    index_at_start_of_input: usize,
    decode_table: &[u8; 256],
    output: &mut [u8],
) -> Result<(), DecodeError>

Decode 8 bytes of input into 6 bytes of output. 8 bytes of output will be written, but only the first 6 of those contain meaningful data.

input is the bytes to decode, of which the first 8 bytes will be processed. index_at_start_of_input is the offset in the overall input (used for reporting errors accurately) decode_table is the lookup table for the particular base64 alphabet. output will have its first 8 bytes overwritten, of which only the first 6 are valid decoded data.