opthash 0.1.2

Rust implementations of Elastic Hashing and Funnel Hashing
Documentation 
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pub(crate) mod config;
pub(crate) mod control;
pub(crate) mod layout;
pub(crate) mod math;
mod simd;

#[cfg(test)]
mod tests {
    use super::control::{
        CTRL_EMPTY, CTRL_TOMBSTONE, Controls, control_fingerprint, fingerprint_bit,
    };
    use super::layout::{GroupMeta, RawTable};

    #[test]
    fn control_group_matches_free_slots() {
        let mut controls = [1u8; 32];
        controls[3] = CTRL_EMPTY;
        controls[22] = CTRL_TOMBSTONE;

        let expected = (1u32 << 3) | (1u32 << 22);
        assert_eq!(controls[..32].match_free_group(), expected);
    }

    #[test]
    fn control_group_matches_fingerprints() {
        let mut controls = [7u8; 32];
        controls[0] = 9;
        controls[17] = 9;
        controls[18] = 3;

        let expected = (1u32 << 0) | (1u32 << 17);
        assert_eq!(controls[..32].match_fingerprint_group(9), expected);
    }

    #[test]
    fn padded_controls_are_empty_sentinels() {
        let table: RawTable<u64> = RawTable::new(18);
        let last_group = table.group_controls(1);
        assert_eq!(last_group[2..], [CTRL_EMPTY; 14]);
    }

    #[test]
    fn group_metadata_tracks_control_transitions() {
        let mut table: RawTable<u64> = RawTable::new(16);
        table.set_control(0, 5);
        table.set_control(1, 7);
        table.mark_tombstone(1);

        assert_eq!(
            table.group_meta(0),
            GroupMeta {
                live: 1,
                tombstones: 1,
                full: false,
            }
        );

        table.clear_control(1);
        assert_eq!(
            table.group_meta(0),
            GroupMeta {
                live: 1,
                tombstones: 0,
                full: false,
            }
        );
    }

    #[test]
    fn group_masks_ignore_padded_tail() {
        let mut table: RawTable<u64> = RawTable::new(18);
        table.set_control(16, 11);
        assert_eq!(table.group_match_mask(1, 11), 0b1);
        assert_eq!(table.group_free_mask(1) & !0b11, 0);
    }

    #[test]
    fn fingerprint_summary_bit_matches_fingerprint_domain() {
        let fp = control_fingerprint(0xDEAD_BEEF);
        let bit = fingerprint_bit(fp);
        assert_ne!(bit, 0);
    }
}