From a4c4019032a2482ba0e071531ff678d9548145f9 Mon Sep 17 00:00:00 2001
From: dcpu <42736967+dcpu@users.noreply.github.com>
Date: Mon, 3 Sep 2018 23:41:06 +0900
Subject: [PATCH] cache: improve performance by not sending info requests for
 cached chunks

---
 backend/cache/object.go | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/backend/cache/object.go b/backend/cache/object.go
index c567a822c..d468981c5 100644
--- a/backend/cache/object.go
+++ b/backend/cache/object.go
@@ -208,11 +208,17 @@ func (o *Object) SetModTime(t time.Time) error {
 
 // Open is used to request a specific part of the file using fs.RangeOption
 func (o *Object) Open(options ...fs.OpenOption) (io.ReadCloser, error) {
-	if err := o.refreshFromSource(true); err != nil {
+	var err error
+
+	if o.Object == nil {
+		err = o.refreshFromSource(true)
+	} else {
+		err = o.refresh()
+	}
+	if err != nil {
 		return nil, err
 	}
 
-	var err error
 	cacheReader := NewObjectHandle(o, o.CacheFs)
 	var offset, limit int64 = 0, -1
 	for _, option := range options {