[#661] blobovniczatree: Add Rebuild implementation

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

pkg/local_object_storage/blobstor/blobovniczatree/cache.go

@@ -15,8 +15,9 @@ import (
 type dbCache struct {
 	cacheGuard *sync.RWMutex
 	cache      simplelru.LRUCache[string, *sharedDB]
-	pathLock   *utilSync.KeyLocker[string]
+	pathLock   *utilSync.KeyLocker[string] // the order of locks is important: pathLock first, cacheGuard second
 	closed     bool
+	nonCached  map[string]struct{}
 
 	dbManager *dbManager
 }
@@ -34,6 +35,7 @@ func newDBCache(size int, dbManager *dbManager) *dbCache {
 		cache:      cache,
 		dbManager:  dbManager,
 		pathLock:   utilSync.NewKeyLocker[string](),
+		nonCached:  make(map[string]struct{}),
 	}
 }
 
@@ -59,6 +61,27 @@ func (c *dbCache) GetOrCreate(path string) *sharedDB {
 	return c.create(path)
 }
 
+func (c *dbCache) EvictAndMarkNonCached(path string) {
+	c.pathLock.Lock(path)
+	defer c.pathLock.Unlock(path)
+
+	c.cacheGuard.Lock()
+	defer c.cacheGuard.Unlock()
+
+	c.cache.Remove(path)
+	c.nonCached[path] = struct{}{}
+}
+
+func (c *dbCache) RemoveFromNonCached(path string) {
+	c.pathLock.Lock(path)
+	defer c.pathLock.Unlock(path)
+
+	c.cacheGuard.Lock()
+	defer c.cacheGuard.Unlock()
+
+	delete(c.nonCached, path)
+}
+
 func (c *dbCache) getExisted(path string) *sharedDB {
 	c.cacheGuard.Lock()
 	defer c.cacheGuard.Unlock()
@@ -94,7 +117,9 @@ func (c *dbCache) put(path string, db *sharedDB) bool {
 	c.cacheGuard.Lock()
 	defer c.cacheGuard.Unlock()
 
-	if !c.closed {
+	_, isNonCached := c.nonCached[path]
+
+	if !isNonCached && !c.closed {
 		c.cache.Add(path, db)
 		return true
 	}