From fdcf72836a2e4c769cc61b7a4c8b98e5b250f64a Mon Sep 17 00:00:00 2001
From: Mark Haines <mjark@negativecurvature.net>
Date: Mon, 7 Aug 2017 15:44:56 +0100
Subject: [PATCH] More comment

---
 src/github.com/matrix-org/dendrite/roomserver/types/types.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/github.com/matrix-org/dendrite/roomserver/types/types.go b/src/github.com/matrix-org/dendrite/roomserver/types/types.go
index 4ce14194a..c3298342a 100644
--- a/src/github.com/matrix-org/dendrite/roomserver/types/types.go
+++ b/src/github.com/matrix-org/dendrite/roomserver/types/types.go
@@ -181,6 +181,8 @@ type RoomRecentEventsUpdater interface {
 // A MembershipUpdater is used to update the membership of a user in a room.
 // (On postgresql this wraps a database transaction that holds a "FOR UPDATE"
 //  lock on the row in the membership table for this user in the room)
+// The caller should call one of SetToInvite, SetToJoin or SetToLeave once to
+// make the update, or none of them if no update is required.
 type MembershipUpdater interface {
 	// True if the target user is invited to the room.
 	IsInvite() bool
@@ -192,6 +194,7 @@ type MembershipUpdater interface {
 	// Returns whether this invite needs to be sent
 	SetToInvite(event gomatrixserverlib.Event) (needsSending bool, err error)
 	// Set the state to join.
+	// Returns a list of invite event IDs that this state change retired.
 	SetToJoin(senderUserID string) (inviteEventIDs []string, err error)
 	// Set the state to leave.
 	// Returns a list of invite event IDs that this state change retired.