hub: add ExpiryMap.UpdateExpiration and sync SMART fetch intervals (#1800)

- Update smartFetchMap expiration when agent smart interval changes
- Prevent background SMART fetching before initial system details are
loaded
- Add buffer to SMART fetch timing check
- Get rid of unnecessary pointers in expirymap

Author: henrygd

internal/hub/expirymap/expirymap.go

@@ -16,15 +16,15 @@ type val[T comparable] struct {
 }
 
 type ExpiryMap[T comparable] struct {
-	store    *store.Store[string, *val[T]]
+	store    store.Store[string, val[T]]
 	stopChan chan struct{}
 	stopOnce sync.Once
 }
 
 // New creates a new expiry map with custom cleanup interval
 func New[T comparable](cleanupInterval time.Duration) *ExpiryMap[T] {
 	m := &ExpiryMap[T]{
-		store:    store.New(map[string]*val[T]{}),
+		store:    *store.New(map[string]val[T]{}),
 		stopChan: make(chan struct{}),
 	}
 	go m.startCleaner(cleanupInterval)
@@ -33,7 +33,7 @@ func New[T comparable](cleanupInterval time.Duration) *ExpiryMap[T] {
 
 // Set stores a value with the given TTL
 func (m *ExpiryMap[T]) Set(key string, value T, ttl time.Duration) {
-	m.store.Set(key, &val[T]{
+	m.store.Set(key, val[T]{
 		value:   value,
 		expires: time.Now().Add(ttl),
 	})
@@ -116,3 +116,12 @@ func (m *ExpiryMap[T]) cleanup() {
 		}
 	}
 }
+
+// UpdateExpiration updates the expiration time of a key
+func (m *ExpiryMap[T]) UpdateExpiration(key string, ttl time.Duration) {
+	value, ok := m.store.GetOk(key)
+	if ok {
+		value.expires = time.Now().Add(ttl)
+		m.store.Set(key, value)
+	}
+}

internal/hub/expirymap/expirymap_test.go

@@ -178,6 +178,33 @@ func TestExpiryMap_GenericTypes(t *testing.T) {
 	})
 }
 
+func TestExpiryMap_UpdateExpiration(t *testing.T) {
+	em := New[string](time.Hour)
+
+	// Set a value with short TTL
+	em.Set("key1", "value1", time.Millisecond*50)
+
+	// Verify it exists
+	assert.True(t, em.Has("key1"))
+
+	// Update expiration to a longer TTL
+	em.UpdateExpiration("key1", time.Hour)
+
+	// Wait for the original TTL to pass
+	time.Sleep(time.Millisecond * 100)
+
+	// Should still exist because expiration was updated
+	assert.True(t, em.Has("key1"))
+	value, ok := em.GetOk("key1")
+	assert.True(t, ok)
+	assert.Equal(t, "value1", value)
+
+	// Try updating non-existent key (should not panic)
+	assert.NotPanics(t, func() {
+		em.UpdateExpiration("nonexistent", time.Hour)
+	})
+}
+
 func TestExpiryMap_ZeroValues(t *testing.T) {
 	em := New[string](time.Hour)
 

internal/hub/systems/system.go

@@ -139,13 +139,25 @@ func (sys *System) update() error {
 	// create system records
 	_, err = sys.createRecords(data)
 
+	// if details were included and fetched successfully, mark details as fetched and update smart interval if set by agent
+	if err == nil && data.Details != nil {
+		sys.detailsFetched.Store(true)
+		// update smart interval if it's set on the agent side
+		if data.Details.SmartInterval > 0 {
+			sys.smartInterval = data.Details.SmartInterval
+			// make sure we reset expiration of lastFetch to remain as long as the new smart interval
+			// to prevent premature expiration leading to new fetch if interval is different.
+			sys.manager.smartFetchMap.UpdateExpiration(sys.Id, sys.smartInterval+time.Minute)
+		}
+	}
+
 	// Fetch and save SMART devices when system first comes online or at intervals
-	if backgroundSmartFetchEnabled() {
+	if backgroundSmartFetchEnabled() && sys.detailsFetched.Load() {
 		if sys.smartInterval <= 0 {
 			sys.smartInterval = time.Hour
 		}
 		lastFetch, _ := sys.manager.smartFetchMap.GetOk(sys.Id)
-		if time.Since(time.UnixMilli(lastFetch)) >= sys.smartInterval && sys.smartFetching.CompareAndSwap(false, true) {
+		if time.Since(time.UnixMilli(lastFetch-1e4)) >= sys.smartInterval && sys.smartFetching.CompareAndSwap(false, true) {
 			go func() {
 				defer sys.smartFetching.Store(false)
 				sys.manager.smartFetchMap.Set(sys.Id, time.Now().UnixMilli(), sys.smartInterval+time.Minute)
@@ -223,11 +235,6 @@ func (sys *System) createRecords(data *system.CombinedData) (*core.Record, error
 			if err := createSystemDetailsRecord(txApp, data.Details, sys.Id); err != nil {
 				return err
 			}
-			sys.detailsFetched.Store(true)
-			// update smart interval if it's set on the agent side
-			if data.Details.SmartInterval > 0 {
-				sys.smartInterval = data.Details.SmartInterval
-			}
 		}
 
 		// update system record (do this last because it triggers alerts and we need above records to be inserted first)