From 7a13816e9406548e93176ab887f73f7eef1dee83 Mon Sep 17 00:00:00 2001
From: Chris Lu <chris.lu@gmail.com>
Date: Sun, 5 Sep 2021 23:17:15 -0700
Subject: [PATCH] refactor

---
 weed/server/master_grpc_server_volume.go | 3 ++-
 weed/server/master_server_handlers.go    | 3 ++-
 weed/topology/topology.go                | 4 ++--
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/weed/server/master_grpc_server_volume.go b/weed/server/master_grpc_server_volume.go
index 4b975a0c4..eba2ab640 100644
--- a/weed/server/master_grpc_server_volume.go
+++ b/weed/server/master_grpc_server_volume.go
@@ -147,8 +147,9 @@ func (ms *MasterServer) Assign(ctx context.Context, req *master_pb.AssignRequest
 	)
 
 	for time.Now().Sub(startTime) < maxTimeout {
-		fid, count, dn, err := ms.Topo.PickForWrite(req.Count, option)
+		fid, count, dnList, err := ms.Topo.PickForWrite(req.Count, option)
 		if err == nil {
+			dn := dnList.Head()
 			return &master_pb.AssignResponse{
 				Fid:       fid,
 				Url:       dn.Url(),
diff --git a/weed/server/master_server_handlers.go b/weed/server/master_server_handlers.go
index 2a1f6d523..36c4239fb 100644
--- a/weed/server/master_server_handlers.go
+++ b/weed/server/master_server_handlers.go
@@ -130,9 +130,10 @@ func (ms *MasterServer) dirAssignHandler(w http.ResponseWriter, r *http.Request)
 			return
 		}
 	}
-	fid, count, dn, err := ms.Topo.PickForWrite(requestedCount, option)
+	fid, count, dnList, err := ms.Topo.PickForWrite(requestedCount, option)
 	if err == nil {
 		ms.maybeAddJwtAuthorization(w, fid, true)
+		dn := dnList.Head()
 		writeJsonQuiet(w, r, http.StatusOK, operation.AssignResult{Fid: fid, Url: dn.Url(), PublicUrl: dn.PublicUrl, Count: count})
 	} else {
 		writeJsonQuiet(w, r, http.StatusNotAcceptable, operation.AssignResult{Error: err.Error()})
diff --git a/weed/topology/topology.go b/weed/topology/topology.go
index 4cbe22a42..39fc7dcad 100644
--- a/weed/topology/topology.go
+++ b/weed/topology/topology.go
@@ -136,7 +136,7 @@ func (t *Topology) HasWritableVolume(option *VolumeGrowOption) bool {
 	return active > 0
 }
 
-func (t *Topology) PickForWrite(count uint64, option *VolumeGrowOption) (string, uint64, *DataNode, error) {
+func (t *Topology) PickForWrite(count uint64, option *VolumeGrowOption) (string, uint64, *VolumeLocationList, error) {
 	vid, count, datanodes, err := t.GetVolumeLayout(option.Collection, option.ReplicaPlacement, option.Ttl, option.DiskType).PickForWrite(count, option)
 	if err != nil {
 		return "", 0, nil, fmt.Errorf("failed to find writable volumes for collection:%s replication:%s ttl:%s error: %v", option.Collection, option.ReplicaPlacement.String(), option.Ttl.String(), err)
@@ -145,7 +145,7 @@ func (t *Topology) PickForWrite(count uint64, option *VolumeGrowOption) (string,
 		return "", 0, nil, fmt.Errorf("no writable volumes available for collection:%s replication:%s ttl:%s", option.Collection, option.ReplicaPlacement.String(), option.Ttl.String())
 	}
 	fileId := t.Sequence.NextFileId(count)
-	return needle.NewFileId(*vid, fileId, rand.Uint32()).String(), count, datanodes.Head(), nil
+	return needle.NewFileId(*vid, fileId, rand.Uint32()).String(), count, datanodes, nil
 }
 
 func (t *Topology) GetVolumeLayout(collectionName string, rp *super_block.ReplicaPlacement, ttl *needle.TTL, diskType types.DiskType) *VolumeLayout {