chore: no compaction of L0 and L1 is triggered when L0'size reaches level0_file_num_compaction_trigger in simple leveled

[zztaki]

Hello, I found a bug in simple_leveled.rs.

When the number of SSTs in L0 is larger than or equal to level0_file_num_compaction_trigger, we still recheck size_ratio_percent. This causes our L0 size to potentially exceed it.

mini-lsm/mini-lsm/src/compact/simple_leveled.rs

Lines 46 to 72 in 23802b2

	for i in 0..self.options.max_levels {
	if i == 0
	&& snapshot.l0_sstables.len() < self.options.level0_file_num_compaction_trigger
	{
	continue;
	}
	let lower_level = i + 1;
	let size_ratio = level_sizes[lower_level] as f64 / level_sizes[i] as f64;
	if size_ratio < self.options.size_ratio_percent as f64 / 100.0 {
	println!(
	"compaction triggered at level {} and {} with size ratio {}",
	i, lower_level, size_ratio
	);
	return Some(SimpleLeveledCompactionTask {
	upper_level: if i == 0 { None } else { Some(i) },
	upper_level_sst_ids: if i == 0 {
	snapshot.l0_sstables.clone()
	} else {
	snapshot.levels[i - 1].1.clone()
	},
	lower_level,
	lower_level_sst_ids: snapshot.levels[lower_level - 1].1.clone(),
	is_lower_level_bottom_level: lower_level == self.options.max_levels,
	});
	}
	}

I'm not sure if I misunderstood the tutorial. :)

[skyzh]

Ahh, I missed it. Do you want to submit patches to fix it? Or I can fix it.

[zztaki]

Thank you for your reply. I would like to submit patches. :)