Address Spencer's PR comments

Changes integer base on capacity gossip keys and adds TODO
for possible speedup.

gossip/keys.go

@@ -35,7 +35,7 @@ const (
 	KeyConfigZone = "zones"
 
 	// KeyMaxAvailCapacityPrefix is the key prefix for gossiping available
-	// store capacity. The suffix is composed of: <hex node ID>-<hex store ID>.
+	// store capacity. The suffix is composed of: <node ID>-<store ID>.
 	// The value is a storage.StoreDescriptor struct.
 	KeyMaxAvailCapacityPrefix = "max-avail-capacity-"
 

server/node.go

@@ -370,8 +370,8 @@ func (n *Node) gossipCapacities() {
 		}
 		// Unique gossip key per store.
 		keyMaxCapacity := gossip.KeyMaxAvailCapacityPrefix +
-			strconv.FormatInt(int64(storeDesc.Node.NodeID), 16) + "-" +
-			strconv.FormatInt(int64(storeDesc.StoreID), 16)
+			strconv.FormatInt(int64(storeDesc.Node.NodeID), 10) + "-" +
+			strconv.FormatInt(int64(storeDesc.StoreID), 10)
 		// Gossip store descriptor.
 		n.gossip.AddInfo(keyMaxCapacity, *storeDesc, ttlCapacityGossip)
 		return nil

storage/store_finder.go

@@ -54,6 +54,10 @@ func (s *Store) capacityGossipUpdate(key string, contentsChanged bool) {
 //
 // If it cannot retrieve a StoreDescriptor from the Store's gossip, it garbage
 // collects the failed key.
+//
+// TODO(embark, spencer): consider using a reverse index map from Attr->stores,
+// for efficiency.  Ensure that entries in this map still have an opportunity
+// to be garbage collected.
 func (s *Store) findStores(required proto.Attributes) ([]*StoreDescriptor, error) {
 	s.finderContext.Lock()
 	defer s.finderContext.Unlock()