1 files changed, 74 insertions, 0 deletions
diff --git a/object/storer/mix/mru.go b/object/storer/mix/mru.go
new file mode 100644
index 00000000..172a641a
--- /dev/null
+++ b/object/storer/mix/mru.go
@@ -0,0 +1,74 @@
+package mix
+
+import "codeberg.org/lindenii/furgit/object/storer"
+
+type backendNode struct {
+	backend objectstorer.Store
+	prev    *backendNode
+	next    *backendNode
+}
+
+//nolint:ireturn
+func (mix *Mix) firstBackend() objectstorer.Store {
+	mix.mu.RLock()
+	defer mix.mu.RUnlock()
+
+	if mix.backendHead == nil {
+		return nil
+	}
+
+	return mix.backendHead.backend
+}
+
+//nolint:ireturn
+func (mix *Mix) nextBackend(current objectstorer.Store) objectstorer.Store {
+	mix.mu.RLock()
+	defer mix.mu.RUnlock()
+
+	node := mix.backendNodeByStore[current]
+	if node == nil || node.next == nil {
+		return nil
+	}
+
+	return node.next.backend
+}
+
+func (mix *Mix) touchBackend(backend objectstorer.Store) {
+	if backend == nil {
+		return
+	}
+
+	if !mix.mu.TryLock() {
+		return
+	}
+	defer mix.mu.Unlock()
+
+	node := mix.backendNodeByStore[backend]
+	if node == nil || node == mix.backendHead {
+		return
+	}
+
+	if node.prev != nil {
+		node.prev.next = node.next
+	}
+
+	if node.next != nil {
+		node.next.prev = node.prev
+	}
+
+	if mix.backendTail == node {
+		mix.backendTail = node.prev
+	}
+
+	node.prev = nil
+
+	node.next = mix.backendHead
+	if mix.backendHead != nil {
+		mix.backendHead.prev = node
+	}
+
+	mix.backendHead = node
+	if mix.backendTail == nil {
+		mix.backendTail = node
+	}
+}