Function encode_vlq

blobby/src/encode.rs:7–28

(mut val: usize, buf: &mut [u8; 4])

/// Returns the slice within `buf` that holds the value.
#[allow(clippy::cast_possible_truncation)]
fn encode_vlq(mut val: usize, buf: &mut [u8; 4]) -> &[u8] {
    macro_rules! step {
        ($n:expr) => {
            buf[$n] = if $n == 3 {
                (val & (VAL_MASK as usize)) as u8
            } else {
                val -= 1;
                NEXT_MASK | (val & (VAL_MASK as usize)) as u8
            };
            val >>= 7;
            if val == 0 {
                return &buf[$n..];
            }
        };
    }

    step!(3);
    step!(2);
    step!(1);
    step!(0);
    panic!("integer is too big")
}

/// Encode the given collection of binary blobs in .blb format into `writer`.
/// Returns the encoded data together with a count of the number of blobs included in the index.