update phoenix client state

-add topics
- remove_topics
- add_presences
- remove_presences
This commit is contained in:
Berenice Medel 2021-12-09 01:26:28 -06:00 committed by Chris McCord
parent bd927bf8b2
commit 4634d32295
2 changed files with 82 additions and 16 deletions

View file

@ -23,7 +23,7 @@ defmodule LiveBeats.Application do
LiveBeatsWeb.Endpoint,
# Start a worker by calling: LiveBeats.Worker.start_link(arg)
# {LiveBeats.Worker, arg}
{Phoenix.Presence.Client, client: LiveBeats.PresenceClient, pubsub: LiveBeats.PubSub, presence: LiveBeats.Presence}
{Phoenix.Presence.Client, client: LiveBeats.PresenceClient, pubsub: LiveBeats.PubSub, presence: LiveBeatsWeb.Presence}
]
# See https://hexdocs.pm/elixir/Supervisor.html

View file

@ -51,35 +51,101 @@ defmodule Phoenix.Presence.Client do
defp track_pid(state, pid, topic, key, meta) do
case Map.fetch(state.topics, topic) do
{:ok, presences} ->
{:ok, _topic_content} ->
state.presence_mod.track(pid, topic, key, meta)
# update topics state...
# new_state
state
update_topics_state(:add_new_presence, state, topic, key, meta)
:error ->
# subscribe to topic we weren't yet tracking
Phoenix.PubSub.subscribe(state.pubsub, topic)
# new_state
state
state.presence_mod.track(pid, topic, key, meta)
update_topics_state(:add_new_topic, state, topic, key, meta)
end
end
defp untrack_pid(state, pid, topic, key) do
state.presence_mod.untrack(pid, topic, key)
# remove presence from state.topics
if Map.has_key?(state.topics, topic) do
presences_count =
state.topics[topic]
|> Map.keys()
|> Enum.count()
# if no more presences for given topic, unsubscribe
# Phoenix.PubSub.unsubscribe(state.pubsub, topic)
# new_state
if presences_count == 0 do
Phoenix.PubSub.unsubscribe(state.pubsub, topic)
update_topics_state(:remove_topic, state, topic, key)
else
update_topics_state(:remove_presence, state, topic, key)
end
else
state
end
end
defp merge_diff(state, topic, diff) do
# is a join
defp merge_diff(state, topic, %{leaves: leaves, joins: joins}) when map_size(leaves) == 0 do
# merge diff into state.topics
# invoke state.client.handle_join|handle_leave
joined_key = Map.keys(joins) |> hd
joined_meta = joins[joined_key].metas |> hd
state.client.handle_join(topic, joined_key, joined_meta, state)
if Map.has_key?(state.topics, topic) do
update_topics_state(:add_new_presence, state, topic, joined_key, joined_meta)
else
update_topics_state(:add_new_topic, state, topic, joined_key, joined_meta)
end
end
defp merge_diff(state, topic, %{leaves: leaves, joins: joins}) when map_size(joins) == 0 do
presences_count =
state.topics[topic]
|> Map.keys()
|> Enum.count()
leaved_key = Map.keys(leaves) |> hd
left_meta = leaves[leaved_key].metas |> hd
state.client.handle_leave(topic, leaved_key, left_meta, state)
# if no more presences for given topic, unsubscribe
# Phoenix.PubSub.unsubscribe(state.pubsub, topic)
# new_state
state
if presences_count == 0 do
Phoenix.PubSub.unsubscribe(state.pubsub, topic)
update_topics_state(:remove_topic, state, topic, leaved_key)
else
update_topics_state(:remove_presence, state, topic, leaved_key)
end
end
defp update_topics_state(:add_new_topic, %{topics: topics} = state, topic, key, meta) do
topic_presences = %{key => meta}
updated_topics = Map.put_new(topics, topic, topic_presences)
Map.put(state, :topics, updated_topics)
end
defp update_topics_state(:add_new_presence, %{topics: topics} = state, topic, key, meta) do
updated_topic =
topics[topic]
|> Map.put_new(key, meta)
updated_topics = Map.put(topics, topic, updated_topic)
Map.put(state, :topics, updated_topics)
end
defp update_topics_state(:remove_topic, %{topics: topics} = state, topic, _key) do
updated_topics = Map.delete(topics, topic)
Map.put(state, :topics, updated_topics)
end
defp update_topics_state(:remove_presence, %{topics: topics} = state, topic, key) do
updated_presences =
topics[topic]
|> Map.delete(key)
updated_topics = Map.put(topics, topic, updated_presences)
Map.put(state, :topics, updated_topics)
end
end