1 files changed, 29 insertions, 0 deletions
diff --git a/object/store/mix/size.go b/object/store/mix/size.go
new file mode 100644
index 00000000..4feb142e
--- /dev/null
+++ b/object/store/mix/size.go
@@ -0,0 +1,29 @@
+package mix
+
+import (
+	"errors"
+	"fmt"
+
+	objectid "codeberg.org/lindenii/furgit/object/id"
+	objectstore "codeberg.org/lindenii/furgit/object/store"
+)
+
+// ReadSize reads object content length from one backend that has it.
+func (mix *Mix) ReadSize(id objectid.ObjectID) (int64, error) {
+	for i, backend := 0, mix.firstBackend(); backend != nil; i, backend = i+1, mix.nextBackend(backend) {
+		size, err := backend.ReadSize(id)
+		if err == nil {
+			mix.touchBackend(backend)
+
+			return size, nil
+		}
+
+		if errors.Is(err, objectstore.ErrObjectNotFound) {
+			continue
+		}
+
+		return 0, fmt.Errorf("objectstore: backend %d read size: %w", i, err)
+	}
+
+	return 0, objectstore.ErrObjectNotFound
+}