66 lines
1.9 KiB
Rust
66 lines
1.9 KiB
Rust
//! Snapshot cache helpers for the portal request path.
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//!
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//! CONTRACT: this module only owns short-lived in-process cache behavior.
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//! It must not change snapshot payloads, source collection, API routes or
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//! business calculations.
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use std::collections::BTreeMap;
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use std::sync::{Arc, Mutex};
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use std::time::{Duration, Instant};
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use crate::{Cli, HealthResponse, Snapshot, build_health, build_snapshot, now};
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const SNAPSHOT_CACHE_TTL: Duration = Duration::from_secs(120);
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pub(crate) type SnapshotCache = Arc<Mutex<Option<CachedSnapshot>>>;
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#[derive(Clone, Debug)]
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pub(crate) struct CachedSnapshot {
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created: Instant,
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snapshot: Snapshot,
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}
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pub(crate) fn new_snapshot_cache() -> SnapshotCache {
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Arc::new(Mutex::new(None))
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}
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pub(crate) fn clone_snapshot_cache(cache: &SnapshotCache) -> SnapshotCache {
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Arc::clone(cache)
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}
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pub(crate) fn cached_snapshot(args: &Cli, cache: &SnapshotCache) -> Snapshot {
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let mut guard = cache.lock().expect("snapshot cache mutex poisoned");
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if let Some(cached) = guard.as_ref() {
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if cached.created.elapsed() <= SNAPSHOT_CACHE_TTL {
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return cached.snapshot.clone();
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}
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}
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let snapshot = build_snapshot(args);
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*guard = Some(CachedSnapshot {
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created: Instant::now(),
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snapshot: snapshot.clone(),
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});
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snapshot
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}
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pub(crate) fn build_fast_health(cache: &SnapshotCache) -> HealthResponse {
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match cache.try_lock() {
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Ok(guard) => guard
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.as_ref()
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.map(|cached| build_health(&cached.snapshot))
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.unwrap_or_else(lightweight_health),
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Err(_) => lightweight_health(),
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}
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}
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fn lightweight_health() -> HealthResponse {
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let mut sources = BTreeMap::new();
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sources.insert("portal".to_string(), true);
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HealthResponse {
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ok: true,
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generated_at_utc: now(),
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version: env!("CARGO_PKG_VERSION").to_string(),
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sources,
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}
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}
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