From 2a1f396df5abd47e7fc4a58c3bc39675e1e84e4f Mon Sep 17 00:00:00 2001
From: Chris Lu <chris.lu@gmail.com>
Date: Sun, 12 Apr 2020 01:06:50 -0700
Subject: [PATCH] avoid duplicated setting chunks into cache

---
 weed/util/chunk_cache/chunk_cache.go | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/weed/util/chunk_cache/chunk_cache.go b/weed/util/chunk_cache/chunk_cache.go
index ead7a8d0b..48e4bfb0d 100644
--- a/weed/util/chunk_cache/chunk_cache.go
+++ b/weed/util/chunk_cache/chunk_cache.go
@@ -54,6 +54,10 @@ func (c *ChunkCache) GetChunk(fileId string) (data []byte) {
 	c.RLock()
 	defer c.RUnlock()
 
+	return c.doGetChunk(fileId)
+}
+
+func (c *ChunkCache) doGetChunk(fileId string) (data []byte) {
 	if data = c.memCache.GetChunk(fileId); data != nil {
 		return data
 	}
@@ -86,6 +90,13 @@ func (c *ChunkCache) SetChunk(fileId string, data []byte) {
 	c.Lock()
 	defer c.Unlock()
 
+	if existingData := c.doGetChunk(fileId); len(existingData)==0{
+		c.doSetChunk(fileId, data)
+	}
+}
+
+func (c *ChunkCache) doSetChunk(fileId string, data []byte) {
+
 	c.memCache.SetChunk(fileId, data)
 
 	if len(c.diskCaches) == 0 {