close evicted era files

common/lru/basiclru.go

@@ -22,9 +22,10 @@ package lru
 // This type is not safe for concurrent use.
 // The zero value is not valid, instances must be created using NewCache.
 type BasicLRU[K comparable, V any] struct {
-	list  *list[K]
-	items map[K]cacheItem[K, V]
-	cap   int
+	list      *list[K]
+	items     map[K]cacheItem[K, V]
+	cap       int
+	onEvicted func(key K, value V)
 }
 
 type cacheItem[K any, V any] struct {
@@ -61,6 +62,10 @@ func (c *BasicLRU[K, V]) Add(key K, value V) (evicted bool) {
 		elem = c.list.removeLast()
 		delete(c.items, elem.v)
 		evicted = true
+		if c.onEvicted != nil {
+			v := c.items[elem.v]
+			c.onEvicted(elem.v, v.value)
+		}
 	} else {
 		elem = new(listElem[K])
 	}
@@ -142,6 +147,11 @@ func (c *BasicLRU[K, V]) RemoveOldest() (key K, value V, ok bool) {
 	return key, item.value, true
 }
 
+// OnEvicted sets a callback function to be called when an item is evicted from the cache.
+func (c *BasicLRU[K, V]) OnEvicted(fn func(k K, v V)) {
+	c.onEvicted = fn
+}
+
 // Keys returns all keys in the cache.
 func (c *BasicLRU[K, V]) Keys() []K {
 	keys := make([]K, 0, len(c.items))

common/lru/lru.go

@@ -93,3 +93,11 @@ func (c *Cache[K, V]) Keys() []K {
 
 	return c.cache.Keys()
 }
+
+// OnEvicted sets a callback function to be called when an item is evicted from the cache.
+func (c *Cache[K, V]) OnEvicted(fn func(key K, value V)) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	c.cache.OnEvicted(fn)
+}

core/rawdb/eradb/eradb.go

@@ -61,19 +61,32 @@ func New(datadir string) (*EraDatabase, error) {
 		return nil, err
 	}
 	db := &EraDatabase{datadir: datadir, cache: lru.NewCache[uint64, *era.Era](openFileLimit)}
+	db.cache.OnEvicted(func(key uint64, value *era.Era) {
+		// Close the era1 file when it is evicted from the cache
+		// to avoid leaks.
+		if value != nil {
+			if err := value.Close(); err != nil {
+				log.Warn("Error closing era1 file", "epoch", key, "err", err)
+			}
+		}
+	})
 	log.Info("Opened erastore", "datadir", datadir)
 	return db, nil
 }
 
 // Close closes all open era1 files in the cache.
-func (db *EraDatabase) Close() {
+func (db *EraDatabase) Close() error {
 	// Close all open era1 files in the cache.
 	keys := db.cache.Keys()
+	errs := make([]error, len(keys))
 	for _, key := range keys {
 		if e, ok := db.cache.Get(key); ok {
-			e.Close()
+			if err := e.Close(); err != nil {
+				errs = append(errs, err)
+			}
 		}
 	}
+	return errors.Join(errs...)
 }
 
 // GetRawBody returns the raw body for a given block number.

core/rawdb/freezer.go

@@ -176,7 +176,9 @@ func (f *Freezer) Close() error {
 			errs = append(errs, err)
 		}
 		if f.eradb != nil {
-			f.eradb.Close()
+			if err := f.eradb.Close(); err != nil {
+				errs = append(errs, err)
+			}
 		}
 	})
 	if errs != nil {