From 2096755ad6a1e7189ade2dddecda5c24a7909045 Mon Sep 17 00:00:00 2001
From: Ilya Averyanov <av@rubybox.dev>
Date: Fri, 21 Jun 2024 13:01:27 +0300
Subject: [PATCH] feat(queue): reorganize group sm callbacks and methods

---
 .../src/emqx_ds_shared_sub_group_sm.erl       | 76 ++++++++++++-------
 1 file changed, 48 insertions(+), 28 deletions(-)

diff --git a/apps/emqx_ds_shared_sub/src/emqx_ds_shared_sub_group_sm.erl b/apps/emqx_ds_shared_sub/src/emqx_ds_shared_sub_group_sm.erl
index 434ea0f14..d1f78bf68 100644
--- a/apps/emqx_ds_shared_sub/src/emqx_ds_shared_sub_group_sm.erl
+++ b/apps/emqx_ds_shared_sub/src/emqx_ds_shared_sub_group_sm.erl
@@ -96,6 +96,35 @@ new(#{
     GSM2 = ensure_state_timeout(GSM1, find_leader_timeout, ?FIND_LEADER_TIMEOUT, find_leader),
     GSM2.
 
+fetch_stream_events(
+    #{
+        state := ?replaying,
+        topic_filter := TopicFilter,
+        state_data := #{stream_lease_events := Events0} = Data
+    } = GSM
+) ->
+    Events1 = lists:map(
+        fun(Event) ->
+            Event#{topic_filter => TopicFilter}
+        end,
+        Events0
+    ),
+    {
+        GSM#{
+            state_data => Data#{stream_lease_events => []}
+        },
+        Events1
+    };
+fetch_stream_events(GSM) ->
+    {GSM, []}.
+
+%%-----------------------------------------------------------------------
+%% Event Handlers
+%%-----------------------------------------------------------------------
+
+%%-----------------------------------------------------------------------
+%% Connecting state
+
 handle_leader_lease_streams(
     #{state := ?connecting, topic_filter := TopicFilter} = GSM, StreamProgresses, Version
 ) ->
@@ -131,6 +160,14 @@ handle_leader_lease_streams(
 handle_leader_lease_streams(GSM, _StreamProgresses, _Version) ->
     GSM.
 
+handle_find_leader_timeout(#{agent := Agent, topic_filter := TopicFilter} = GSM0) ->
+    ok = emqx_ds_shared_sub_registry:lookup_leader(Agent, TopicFilter),
+    GSM1 = ensure_state_timeout(GSM0, find_leader_timeout, ?FIND_LEADER_TIMEOUT, find_leader),
+    GSM1.
+
+%%-----------------------------------------------------------------------
+%% Replaying state
+
 handle_leader_renew_stream_lease(
     #{state := ?replaying, state_data := #{version := Version} = Data} = GSM, Version
 ) ->
@@ -140,40 +177,23 @@ handle_leader_renew_stream_lease(
 handle_leader_renew_stream_lease(GSM, _Version) ->
     GSM.
 
+%%-----------------------------------------------------------------------
+%% Updating state
+
+%%-----------------------------------------------------------------------
+%% Internal API
+%%-----------------------------------------------------------------------
+
 handle_state_timeout(
-    #{agent := Agent, state := ?connecting, topic_filter := TopicFilter} = GSM0,
+    #{state := ?connecting, topic_filter := TopicFilter} = GSM,
     find_leader_timeout,
     find_leader
 ) ->
     ?tp(debug, find_leader_timeout, #{topic_filter => TopicFilter}),
-    ok = emqx_ds_shared_sub_registry:lookup_leader(Agent, TopicFilter),
-    GSM1 = ensure_state_timeout(GSM0, find_leader_timeout, ?FIND_LEADER_TIMEOUT, find_leader),
-    GSM1.
-
-fetch_stream_events(
-    #{
-        state := ?replaying,
-        topic_filter := TopicFilter,
-        state_data := #{stream_lease_events := Events0} = Data
-    } = GSM
-) ->
-    Events1 = lists:map(
-        fun(Event) ->
-            Event#{topic_filter => TopicFilter}
-        end,
-        Events0
-    ),
-    {
-        GSM#{
-            state_data => Data#{stream_lease_events => []}
-        },
-        Events1
-    };
-fetch_stream_events(GSM) ->
-    {GSM, []}.
+    handle_find_leader_timeout(GSM).
 
 handle_info(
-    #{state_timers := Timers} = GSM, #state_timeout{message = Message, name = Name, id = Id} = Msg
+    #{state_timers := Timers} = GSM, #state_timeout{message = Message, name = Name, id = Id} = _Info
 ) ->
     case Timers of
         #{Name := #timer{id = Id}} ->
@@ -182,7 +202,7 @@ handle_info(
             %% Stale timer
             GSM
     end;
-handle_info(GSM, Msg) ->
+handle_info(GSM, _Info) ->
     GSM.
 
 %%--------------------------------------------------------------------