Merge pull request #70 from skyportsystems/perGroupPeerPicker4.1

portPicker function now takes group name

groupcache.go

@@ -198,7 +198,7 @@ func (g *Group) Name() string {
 
 func (g *Group) initPeers() {
  if g.peers == nil {
- g.peers = getPeers()
+ g.peers = getPeers(g.name)
  }
 }
 

peers.go

@@ -47,23 +47,37 @@ type NoPeers struct{}
 func (NoPeers) PickPeer(key string) (peer ProtoGetter, ok bool) { return }
 
 var (
- portPicker func() PeerPicker
+ portPicker func(groupName string) PeerPicker
 )
 
 // RegisterPeerPicker registers the peer initialization function.
 // It is called once, when the first group is created.
+// Either RegisterPeerPicker or RegisterPerGroupPeerPicker should be
+// called exactly once, but not both.
 func RegisterPeerPicker(fn func() PeerPicker) {
+ if portPicker != nil {
+ panic("RegisterPeerPicker called more than once")
+ }
+ portPicker = func(_ string) PeerPicker { return fn() }
+}
+
+// RegisterPerGroupPeerPicker registers the peer initialization function,
+// which takes the groupName, to be used in choosing a PeerPicker.
+// It is called once, when the first group is created.
+// Either RegisterPeerPicker or RegisterPerGroupPeerPicker should be
+// called exactly once, but not both.
+func RegisterPerGroupPeerPicker(fn func(groupName string) PeerPicker) {
  if portPicker != nil {
  panic("RegisterPeerPicker called more than once")
  }
  portPicker = fn
 }
 
-func getPeers() PeerPicker {
+func getPeers(groupName string) PeerPicker {
  if portPicker == nil {
  return NoPeers{}
  }
- pk := portPicker()
+ pk := portPicker(groupName)
  if pk == nil {
  pk = NoPeers{}
  }