1 files changed, 71 insertions, 0 deletions
diff --git a/vendor/github.com/golang/groupcache/peers.go b/vendor/github.com/golang/groupcache/peers.go
new file mode 100644
index 000000000..a74a79b8f
--- /dev/null
+++ b/vendor/github.com/golang/groupcache/peers.go
@@ -0,0 +1,71 @@
+/*
+Copyright 2012 Google Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// peers.go defines how processes find and communicate with their peers.
+
+package groupcache
+
+import (
+	pb "github.com/golang/groupcache/groupcachepb"
+)
+
+// Context is an opaque value passed through calls to the
+// ProtoGetter. It may be nil if your ProtoGetter implementation does
+// not require a context.
+type Context interface{}
+
+// ProtoGetter is the interface that must be implemented by a peer.
+type ProtoGetter interface {
+	Get(context Context, in *pb.GetRequest, out *pb.GetResponse) error
+}
+
+// PeerPicker is the interface that must be implemented to locate
+// the peer that owns a specific key.
+type PeerPicker interface {
+	// PickPeer returns the peer that owns the specific key
+	// and true to indicate that a remote peer was nominated.
+	// It returns nil, false if the key owner is the current peer.
+	PickPeer(key string) (peer ProtoGetter, ok bool)
+}
+
+// NoPeers is an implementation of PeerPicker that never finds a peer.
+type NoPeers struct{}
+
+func (NoPeers) PickPeer(key string) (peer ProtoGetter, ok bool) { return }
+
+var (
+	portPicker func() PeerPicker
+)
+
+// RegisterPeerPicker registers the peer initialization function.
+// It is called once, when the first group is created.
+func RegisterPeerPicker(fn func() PeerPicker) {
+	if portPicker != nil {
+		panic("RegisterPeerPicker called more than once")
+	}
+	portPicker = fn
+}
+
+func getPeers() PeerPicker {
+	if portPicker == nil {
+		return NoPeers{}
+	}
+	pk := portPicker()
+	if pk == nil {
+		pk = NoPeers{}
+	}
+	return pk
+}