coordinode-lsm-tree 7.4.2

Embedded LSM-tree storage engine in pure Rust, no C/C++ dependency. MVCC snapshots, BuRR filters, zstd dictionary compression, columnar PAX blocks, AES-256-GCM at rest, self-healing per-block ECC, compaction on a near-full disk, no_std support.
Documentation 
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use super::*;
use test_log::test;

/// The key hash the index buckets a key by.
fn h(key: &[u8]) -> u64 {
    crate::hash::hash64(key)
}

#[test]
fn hash_index_build_simple() {
    let mut hash_index = Builder::with_bucket_count(100);

    hash_index.set(h(b"a"), 5);
    hash_index.set(h(b"b"), 8);
    hash_index.set(h(b"c"), 10);

    let bytes = hash_index.into_inner();

    // NOTE: Hash index bytes need to be consistent across machines and compilations etc.
    assert_eq!(
        [
            254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 10, 254, 254, 254, 8, 254, 254,
            254, 5, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254,
            254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254,
            254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254,
            254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254,
            254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254, 254
        ],
        &*bytes
    );

    let reader = Reader::new(&bytes, 0, 100);
    assert_eq!(0, reader.conflict_count());

    assert_eq!(5, reader.get(h(b"a")));
    assert_eq!(8, reader.get(h(b"b")));
    assert_eq!(10, reader.get(h(b"c")));
    assert_eq!(MARKER_FREE, reader.get(h(b"d")));
}

#[test]
fn hash_index_build_conflict() {
    let mut hash_index = Builder::with_bucket_count(1);

    hash_index.set(h(b"a"), 5);
    hash_index.set(h(b"b"), 8);

    let bytes = hash_index.into_inner();

    assert_eq!([255], &*bytes);

    assert_eq!(1, Reader::new(&bytes, 0, 1).conflict_count());
}

#[test]
fn hash_index_build_same_offset() {
    let mut hash_index = Builder::with_bucket_count(1);

    hash_index.set(h(b"a"), 5);
    hash_index.set(h(b"b"), 5);

    let bytes = hash_index.into_inner();

    assert_eq!([5], &*bytes);

    let reader = Reader::new(&bytes, 0, 1);
    assert_eq!(0, reader.conflict_count());
    assert_eq!(5, reader.get(h(b"a")));
    assert_eq!(5, reader.get(h(b"b")));
}

#[test]
fn hash_index_build_mix() {
    let mut hash_index = Builder::with_bucket_count(1);

    hash_index.set(h(b"a"), 5);
    hash_index.set(h(b"b"), 5);
    hash_index.set(h(b"c"), 6);

    let bytes = hash_index.into_inner();

    assert_eq!([255], &*bytes);

    assert_eq!(1, Reader::new(&bytes, 0, 1).conflict_count());
}

#[test]
fn hash_index_read_conflict() {
    let mut hash_index = Builder::with_bucket_count(1);

    hash_index.set(h(b"a"), 5);
    hash_index.set(h(b"b"), 8);

    let bytes = hash_index.into_inner();

    let reader = Reader::new(&bytes, 0, 1);
    assert_eq!(MARKER_CONFLICT, reader.get(h(b"a")));
    assert_eq!(MARKER_CONFLICT, reader.get(h(b"b")));
    assert_eq!(MARKER_CONFLICT, reader.get(h(b"c")));

    assert_eq!(1, Reader::new(&bytes, 0, 1).conflict_count());
}