From dcaf1796fe0e41e39ac5c9602cb190cf150e7849 Mon Sep 17 00:00:00 2001
From: Chris Lu <chris.lu@gmail.com>
Date: Wed, 16 Nov 2016 07:09:57 -0800
Subject: [PATCH] add option to enable caching

---
 weed/command/server.go            |  2 ++
 weed/command/volume.go            |  3 +++
 weed/server/volume_server.go      |  4 +++-
 weed/storage/needle_byte_cache.go | 21 +++++++++++++--------
 4 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/weed/command/server.go b/weed/command/server.go
index eed7dcae4..027ba191d 100644
--- a/weed/command/server.go
+++ b/weed/command/server.go
@@ -72,6 +72,7 @@ var (
 	volumeFixJpgOrientation       = cmdServer.Flag.Bool("volume.images.fix.orientation", true, "Adjust jpg orientation when uploading.")
 	volumeReadRedirect            = cmdServer.Flag.Bool("volume.read.redirect", true, "Redirect moved or non-local volumes.")
 	volumeServerPublicUrl         = cmdServer.Flag.String("volume.publicUrl", "", "publicly accessible address")
+	volumeEnableBytesCache        = cmdServer.Flag.Bool("volume.cache.enable", false, "direct cache instead of OS cache, cost more memory.")
 	isStartingFiler               = cmdServer.Flag.Bool("filer", false, "whether to start filer")
 
 	serverWhiteList []string
@@ -259,6 +260,7 @@ func runServer(cmd *Command, args []string) bool {
 		volumeNeedleMapKind,
 		*serverIp+":"+strconv.Itoa(*masterPort), *volumePulse, *serverDataCenter, *serverRack,
 		serverWhiteList, *volumeFixJpgOrientation, *volumeReadRedirect,
+		*volumeEnableBytesCache,
 	)
 
 	glog.V(0).Infoln("Start Seaweed volume server", util.VERSION, "at", *serverIp+":"+strconv.Itoa(*volumePort))
diff --git a/weed/command/volume.go b/weed/command/volume.go
index 21369cbe9..ba498b8e4 100644
--- a/weed/command/volume.go
+++ b/weed/command/volume.go
@@ -36,6 +36,7 @@ type VolumeServerOptions struct {
 	indexType             *string
 	fixJpgOrientation     *bool
 	readRedirect          *bool
+	enableBytesCache      *bool
 }
 
 func init() {
@@ -54,6 +55,7 @@ func init() {
 	v.indexType = cmdVolume.Flag.String("index", "memory", "Choose [memory|leveldb|boltdb] mode for memory~performance balance.")
 	v.fixJpgOrientation = cmdVolume.Flag.Bool("images.fix.orientation", true, "Adjust jpg orientation when uploading.")
 	v.readRedirect = cmdVolume.Flag.Bool("read.redirect", true, "Redirect moved or non-local volumes.")
+	v.enableBytesCache = cmdVolume.Flag.Bool("cache.enable", false, "direct cache instead of OS cache, cost more memory.")
 }
 
 var cmdVolume = &Command{
@@ -132,6 +134,7 @@ func runVolume(cmd *Command, args []string) bool {
 		*v.master, *v.pulseSeconds, *v.dataCenter, *v.rack,
 		v.whiteList,
 		*v.fixJpgOrientation, *v.readRedirect,
+		*v.enableBytesCache,
 	)
 
 	listeningAddress := *v.bindIp + ":" + strconv.Itoa(*v.port)
diff --git a/weed/server/volume_server.go b/weed/server/volume_server.go
index 79a4276b1..1a912a169 100644
--- a/weed/server/volume_server.go
+++ b/weed/server/volume_server.go
@@ -33,7 +33,8 @@ func NewVolumeServer(adminMux, publicMux *http.ServeMux, ip string,
 	dataCenter string, rack string,
 	whiteList []string,
 	fixJpgOrientation bool,
-	readRedirect bool) *VolumeServer {
+	readRedirect bool,
+	enableBytesCache bool) *VolumeServer {
 	vs := &VolumeServer{
 		pulseSeconds:      pulseSeconds,
 		dataCenter:        dataCenter,
@@ -44,6 +45,7 @@ func NewVolumeServer(adminMux, publicMux *http.ServeMux, ip string,
 	}
 	vs.SetMasterNode(masterNode)
 	vs.store = storage.NewStore(port, ip, publicUrl, folders, maxCounts, vs.needleMapKind)
+	storage.EnableBytesCache = enableBytesCache
 
 	vs.guard = security.NewGuard(whiteList, "")
 
diff --git a/weed/storage/needle_byte_cache.go b/weed/storage/needle_byte_cache.go
index ae35a48ba..dfc32bcbf 100644
--- a/weed/storage/needle_byte_cache.go
+++ b/weed/storage/needle_byte_cache.go
@@ -11,8 +11,9 @@ import (
 )
 
 var (
-	bytesCache *lru.Cache
-	bytesPool  *util.BytesPool
+	EnableBytesCache = true
+	bytesCache       *lru.Cache
+	bytesPool        *util.BytesPool
 )
 
 /*
@@ -48,11 +49,13 @@ func (block *Block) increaseReference() {
 func getBytesForFileBlock(r *os.File, offset int64, readSize int) (dataSlice []byte, block *Block, err error) {
 	// check cache, return if found
 	cacheKey := fmt.Sprintf("%d:%d:%d", r.Fd(), offset>>3, readSize)
-	if obj, found := bytesCache.Get(cacheKey); found {
-		block = obj.(*Block)
-		block.increaseReference()
-		dataSlice = block.Bytes[0:readSize]
-		return dataSlice, block, nil
+	if EnableBytesCache {
+		if obj, found := bytesCache.Get(cacheKey); found {
+			block = obj.(*Block)
+			block.increaseReference()
+			dataSlice = block.Bytes[0:readSize]
+			return dataSlice, block, nil
+		}
 	}
 
 	// get the []byte from pool
@@ -61,7 +64,9 @@ func getBytesForFileBlock(r *os.File, offset int64, readSize int) (dataSlice []b
 	block = &Block{Bytes: b, refCount: 2}
 	dataSlice = block.Bytes[0:readSize]
 	_, err = r.ReadAt(dataSlice, offset)
-	bytesCache.Add(cacheKey, block)
+	if EnableBytesCache {
+		bytesCache.Add(cacheKey, block)
+	}
 	return dataSlice, block, err
 }