From 9b6b792ce70e52516a643abba077ee82668db48b Mon Sep 17 00:00:00 2001
From: Ethan Buchman <ethan@coinculture.info>
Date: Fri, 25 Jan 2019 18:11:31 -0500
Subject: [PATCH] pubsub: comments

---
 libs/pubsub/pubsub.go | 32 +++++++++++++++++++++-----------
 1 file changed, 21 insertions(+), 11 deletions(-)

diff --git a/libs/pubsub/pubsub.go b/libs/pubsub/pubsub.go
index b4e392bbd..cb41f8b38 100644
--- a/libs/pubsub/pubsub.go
+++ b/libs/pubsub/pubsub.go
@@ -223,9 +223,11 @@ func (s *Server) Unsubscribe(ctx context.Context, clientID string, query Query)
 	}
 
 	// original query is used here because we're using pointers as map keys
+	// ?
 	select {
 	case s.cmds <- cmd{op: unsub, clientID: clientID, query: origQuery}:
 		s.mtx.Lock()
+		// if its the only query left, should we also delete the client?
 		delete(clientSubscriptions, query.String())
 		s.mtx.Unlock()
 		return nil
@@ -353,20 +355,24 @@ func (state *state) remove(clientID string, q Query) {
 	}
 
 	ch, ok := clientToChannelMap[clientID]
-	if ok {
-		close(ch)
+	if !ok {
+		return
+	}
 
-		delete(state.clients[clientID], q)
+	close(ch)
 
-		// if it not subscribed to anything else, remove the client
-		if len(state.clients[clientID]) == 0 {
-			delete(state.clients, clientID)
-		}
+	// remove the query from client map.
+	// if client is not subscribed to anything else, remove it.
+	delete(state.clients[clientID], q)
+	if len(state.clients[clientID]) == 0 {
+		delete(state.clients, clientID)
+	}
 
-		delete(state.queries[q], clientID)
-		if len(state.queries[q]) == 0 {
-			delete(state.queries, q)
-		}
+	// remove the client from query map.
+	// if query has no other clients subscribed, remove it.
+	delete(state.queries[q], clientID)
+	if len(state.queries[q]) == 0 {
+		delete(state.queries, q)
 	}
 }
 
@@ -380,11 +386,15 @@ func (state *state) removeAll(clientID string) {
 		ch := state.queries[q][clientID]
 		close(ch)
 
+		// remove the client from query map.
+		// if query has no other clients subscribed, remove it.
 		delete(state.queries[q], clientID)
 		if len(state.queries[q]) == 0 {
 			delete(state.queries, q)
 		}
 	}
+
+	// remove the client.
 	delete(state.clients, clientID)
 }