lsm-tree 3.1.4

A K.I.S.S. implementation of log-structured merge trees (LSM-trees/LSMTs)
Documentation 
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use super::*;
use crate::{AbstractTree, Config, SequenceNumberCounter};
use std::sync::Arc;
use test_log::test;

#[test]
fn leveled_empty_levels() -> crate::Result<()> {
    let dir = tempfile::tempdir()?;
    let tree = Config::new(
        dir.path(),
        SequenceNumberCounter::default(),
        SequenceNumberCounter::default(),
    )
    .open()?;

    let strategy = Arc::new(Strategy::default());
    tree.compact(strategy, 0)?;

    assert_eq!(0, tree.table_count());
    Ok(())
}

#[test]
fn leveled_l0_below_limit() -> crate::Result<()> {
    let dir = tempfile::tempdir()?;
    let tree = Config::new(
        dir.path(),
        SequenceNumberCounter::default(),
        SequenceNumberCounter::default(),
    )
    .open()?;

    for i in 0..3u8 {
        tree.insert([b'k', i].as_slice(), "v", 0);
        tree.flush_active_memtable(0)?;
    }

    let before = tree.table_count();
    assert_eq!(3, before);

    let strategy = Arc::new(Strategy::default());
    tree.compact(strategy, 0)?;

    assert_eq!(before, tree.table_count());

    Ok(())
}

#[test]
fn leveled_l0_reached_limit() -> crate::Result<()> {
    let dir = tempfile::tempdir()?;
    let tree = Config::new(
        dir.path(),
        SequenceNumberCounter::default(),
        SequenceNumberCounter::default(),
    )
    .open()?;

    for i in 0..4u8 {
        // NOTE: Tables need to overlap
        tree.insert("a", "v", 0);
        tree.insert([b'k', i].as_slice(), "v", 0);
        tree.insert("z", "v", 0);
        tree.flush_active_memtable(0)?;
    }

    assert_eq!(4, tree.table_count());

    let strategy = Arc::new(Strategy::default());
    tree.compact(strategy, 0)?;

    assert_eq!(1, tree.table_count());

    Ok(())
}

#[test]
fn leveled_l0_reached_limit_disjoint() -> crate::Result<()> {
    let dir = tempfile::tempdir()?;
    let tree = Config::new(
        dir.path(),
        SequenceNumberCounter::default(),
        SequenceNumberCounter::default(),
    )
    .open()?;

    for i in 0..4u8 {
        tree.insert([b'k', i].as_slice(), "v", 0);
        tree.flush_active_memtable(0)?;
    }

    assert_eq!(4, tree.table_count());

    let strategy = Arc::new(Strategy::default());
    tree.compact(strategy, 0)?;

    assert_eq!(4, tree.table_count());

    Ok(())
}

#[test]
fn leveled_l0_reached_limit_disjoint_l1() -> crate::Result<()> {
    let dir = tempfile::tempdir()?;
    let tree = Config::new(
        dir.path(),
        SequenceNumberCounter::default(),
        SequenceNumberCounter::default(),
    )
    .open()?;

    for i in 0..4 {
        // NOTE: Tables need to overlap
        tree.insert("a", "v", i);
        tree.insert("b", "v", i);
        tree.flush_active_memtable(0)?;
    }

    let fifo = Arc::new(Strategy::default());
    tree.compact(fifo, 0)?;

    assert_eq!(1, tree.table_count());

    for i in 0..4u8 {
        tree.insert([b'k', i].as_slice(), "v", 0);
        tree.flush_active_memtable(0)?;
    }

    assert_eq!(5, tree.table_count());

    let strategy = Arc::new(Strategy::default());
    tree.compact(strategy, 0)?;

    assert_eq!(5, tree.table_count());

    Ok(())
}

#[test]
#[expect(clippy::unwrap_used)]
fn leveled_sequential_inserts() -> crate::Result<()> {
    let dir = tempfile::tempdir()?;
    let tree = Config::new(
        dir.path(),
        SequenceNumberCounter::default(),
        SequenceNumberCounter::default(),
    )
    .open()?;

    let strategy = Arc::new(Strategy {
        target_size: 1,
        ..Default::default()
    });

    let mut table_count = 0;

    for k in 0u64..100 {
        table_count += 1;

        tree.insert(k.to_be_bytes(), "", 0);
        tree.flush_active_memtable(0)?;

        assert_eq!(table_count, tree.table_count());
        tree.compact(strategy.clone(), 0)?;
        assert_eq!(table_count, tree.table_count());

        for idx in 1..=5 {
            assert_eq!(
                0,
                tree.current_version().level(idx).unwrap().len(),
                "no tables should be in intermediary level (L{idx})",
            );
        }
    }

    Ok(())
}