11644: Replace linear search with map for looking up mounts by UUID.

diff --git a/services/keepstore/volume.go b/services/keepstore/volume.go
index 0b4bec4f8b2b96acb6a72ae86c9f564f86f8b768..d23fcc81d4902d7ca28c442c2fba935d15914d3d 100644 (file)
--- a/services/keepstore/volume.go
+++ b/services/keepstore/volume.go
@@ -302,6 +302,7 @@ func (*VolumeMount) generateUUID() string {
 // (where writables are all Volumes v where v.Writable()==true).
 type RRVolumeManager struct {
        mounts    []*VolumeMount
+       mountMap  map[string]*VolumeMount
        readables []Volume
        writables []Volume
        counter   uint32
@@ -313,6 +314,7 @@ func MakeRRVolumeManager(volumes []Volume) *RRVolumeManager {
        vm := &RRVolumeManager{
                iostats: make(map[Volume]*ioStats),
        }
+       vm.mountMap = make(map[string]*VolumeMount)
        for _, v := range volumes {
                mnt := &VolumeMount{
                        UUID:     (*VolumeMount)(nil).generateUUID(),
@@ -328,6 +330,7 @@ func MakeRRVolumeManager(volumes []Volume) *RRVolumeManager {
                }
                vm.iostats[v] = &ioStats{}
                vm.mounts = append(vm.mounts, mnt)
+               vm.mountMap[mnt.UUID] = mnt
                vm.readables = append(vm.readables, v)
                if v.Writable() {
                        vm.writables = append(vm.writables, v)
@@ -341,12 +344,11 @@ func (vm *RRVolumeManager) Mounts() []*VolumeMount {
 }
 
 func (vm *RRVolumeManager) Lookup(uuid string, needWrite bool) Volume {
-       for _, mnt := range vm.mounts {
-               if mnt.UUID == uuid && (!needWrite || !mnt.ReadOnly) {
-                       return mnt.volume
-               }
+       if mnt, ok := vm.mountMap[uuid]; ok && (!needWrite || !mnt.ReadOnly) {
+               return mnt.volume
+       } else {
+               return nil
        }
-       return nil
 }
 
 // AllReadable returns an array of all readable volumes