Chart session checkpoints as their own cache bucket

This commit is contained in:
Georg Bauer
2026-07-26 09:56:52 +02:00
parent 5d441038bc
commit f2133d561b
2 changed files with 26 additions and 15 deletions

View File

@@ -371,21 +371,25 @@ impl App {
.into()
}
/// Disc usage of both cache buckets, split by age. The bar is the age
/// distribution of what is stored; the budget governs the transient store
/// only and is reported on its own row.
/// Disc usage of both cache buckets. The bar splits the transient store by
/// age — the order the budget evicts in — and carries the session
/// checkpoints as one further segment, since those are only freed with
/// their session and so compete for disc without ever ageing out.
fn cache_explorer(&self) -> Element<'_, Message> {
let usage = &self.kv_cache_report;
let total = usage.total_bytes();
let capacity = total.max(1);
let segments = crate::metrics::CACHE_AGE_BUCKETS
.iter()
.enumerate()
.map(|(index, (label, _))| (*label, usage.age_bytes[index], AGE_COLORS[index]))
.chain([("Sessions", usage.session_bytes, SESSION_COLOR)]);
let mut bar = row![].height(14).spacing(2);
let mut legend = column![].spacing(6);
for (index, (label, _)) in crate::metrics::CACHE_AGE_BUCKETS.iter().enumerate() {
let bytes = usage.age_bytes[index];
for (label, bytes, color) in segments {
if bytes == 0 {
continue;
}
let color = AGE_COLORS[index];
bar = bar.push(
container(Space::new(Length::Fill, Length::Fill))
.width(Length::FillPortion(portion(bytes, capacity)))
@@ -394,7 +398,7 @@ impl App {
legend = legend.push(
row![
container(Space::new(9, 9)).style(move |_| chart_bar_style(color)),
text(*label).size(12).color(muted_text()),
text(label).size(12).color(muted_text()),
Space::with_width(Length::Fill),
text(format!(
"{} · {:.0}%",
@@ -497,6 +501,9 @@ impl App {
}
}
/// Sessions sit outside the age scale: they are not evicted, only deleted.
const SESSION_COLOR: Color = Color::from_rgb(0.85, 0.44, 0.56);
/// Age buckets from green (fresh) to grey (past every hit half-life).
const AGE_COLORS: [Color; 5] = [
Color::from_rgb(0.28, 0.69, 0.44),

View File

@@ -707,7 +707,8 @@ pub(crate) struct KvCacheReport {
pub(crate) session_files: u64,
pub(crate) transient_bytes: u64,
pub(crate) transient_files: u64,
/// Bytes per [`CACHE_AGE_BUCKETS`] entry, both buckets combined.
/// Bytes per [`CACHE_AGE_BUCKETS`] entry, transient store only: session
/// checkpoints never age out, so their age says nothing about eviction.
pub(crate) age_bytes: [u64; CACHE_AGE_BUCKETS.len()],
pub(crate) entries: Vec<KvCacheEntry>,
}
@@ -752,11 +753,13 @@ pub(crate) fn kv_cache_report(root: &Path, budget_bytes: u64) -> KvCacheReport {
.ok()
.and_then(|modified| now.duration_since(modified).ok())
.map_or(0, |age| age.as_secs());
if transient {
let bucket = CACHE_AGE_BUCKETS
.iter()
.position(|(_, limit)| age_seconds < *limit)
.unwrap_or(CACHE_AGE_BUCKETS.len() - 1);
report.age_bytes[bucket] += bytes;
}
// Index files are counted in the totals but folded into their
// checkpoint's row.
if path.extension().is_some_and(|value| value == "meta") {
@@ -915,8 +918,9 @@ mod tests {
assert_eq!(report.session_files, 1);
assert_eq!(report.transient_bytes, 140);
assert_eq!(report.transient_files, 2);
// Fresh files in the first bucket, the two-day-old one in "17d".
assert_eq!(report.age_bytes[0], 340);
// Only the transient store is bucketed by age: its fresh index file in
// the first bucket, its two-day-old checkpoint in "17d".
assert_eq!(report.age_bytes[0], 40);
assert_eq!(report.age_bytes[3], 100);
assert_eq!(
(