1 files changed, 49 insertions, 18 deletions

diff --git a/lib/pleroma/web/mastodon_api/websocket_handler.ex b/lib/pleroma/web/mastodon_api/websocket_handler.ex
index b1aebe014..94e4595d8 100644
--- a/lib/pleroma/web/mastodon_api/websocket_handler.ex
+++ b/lib/pleroma/web/mastodon_api/websocket_handler.ex
@@ -12,8 +12,12 @@ defmodule Pleroma.Web.MastodonAPI.WebsocketHandler do
 
   @behaviour :cowboy_websocket
 
-  # Handled by periodic keepalive in Pleroma.Web.Streamer.Ping.
-  @timeout :infinity
+  # Client ping period.
+  @tick :timer.seconds(30)
+  # Cowboy timeout period.
+  @timeout :timer.seconds(60)
+  # Hibernate every X messages
+  @hibernate_every 100
 
   def init(%{qs: qs} = req, state) do
     with params <- Enum.into(:cow_qs.parse_qs(qs), %{}),
@@ -28,7 +32,8 @@ defmodule Pleroma.Web.MastodonAPI.WebsocketHandler do
           req
         end
 
-      {:cowboy_websocket, req, %{user: user, topic: topic}, %{idle_timeout: @timeout}}
+      {:cowboy_websocket, req, %{user: user, topic: topic, count: 0, timer: nil},
+       %{idle_timeout: @timeout}}
     else
       {:error, :bad_topic} ->
         Logger.debug("#{__MODULE__} bad topic #{inspect(req)}")
@@ -43,28 +48,54 @@ defmodule Pleroma.Web.MastodonAPI.WebsocketHandler do
   end
 
   def websocket_init(state) do
-    send(self(), :subscribe)
-    {:ok, state}
-  end
-
-  # We never receive messages.
-  def websocket_handle(_frame, state) do
-    {:ok, state}
-  end
-
-  def websocket_info(:subscribe, state) do
     Logger.debug(
       "#{__MODULE__} accepted websocket connection for user #{
         (state.user || %{id: "anonymous"}).id
       }, topic #{state.topic}"
     )
 
-    Streamer.add_socket(state.topic, streamer_socket(state))
+    Streamer.add_socket(state.topic, state.user)
+    {:ok, %{state | timer: timer()}}
+  end
+
+  # Client's Pong frame.
+  def websocket_handle(:pong, state) do
+    if state.timer, do: Process.cancel_timer(state.timer)
+    {:ok, %{state | timer: timer()}}
+  end
+
+  # We never receive messages.
+  def websocket_handle(frame, state) do
+    Logger.error("#{__MODULE__} received frame: #{inspect(frame)}")
     {:ok, state}
   end
 
+  def websocket_info({:render_with_user, view, template, item}, state) do
+    user = %User{} = User.get_cached_by_ap_id(state.user.ap_id)
+
+    unless Streamer.filtered_by_user?(user, item) do
+      websocket_info({:text, view.render(template, item, user)}, %{state | user: user})
+    else
+      {:ok, state}
+    end
+  end
+
   def websocket_info({:text, message}, state) do
-    {:reply, {:text, message}, state}
+    # If the websocket processed X messages, force an hibernate/GC.
+    # We don't hibernate at every message to balance CPU usage/latency with RAM usage.
+    if state.count > @hibernate_every do
+      {:reply, {:text, message}, %{state | count: 0}, :hibernate}
+    else
+      {:reply, {:text, message}, %{state | count: state.count + 1}}
+    end
+  end
+
+  # Ping tick. We don't re-queue a timer there, it is instead queued when :pong is received.
+  # As we hibernate there, reset the count to 0.
+  # If the client misses :pong, Cowboy will automatically timeout the connection after
+  # `@idle_timeout`.
+  def websocket_info(:tick, state) do
+    {:reply, :ping, %{state | timer: nil, count: 0}, :hibernate}
   end
 
   def terminate(reason, _req, state) do
@@ -74,7 +105,7 @@ defmodule Pleroma.Web.MastodonAPI.WebsocketHandler do
       }, topic #{state.topic || "?"}: #{inspect(reason)}"
     )
 
-    Streamer.remove_socket(state.topic, streamer_socket(state))
+    Streamer.remove_socket(state.topic)
     :ok
   end
 
@@ -96,7 +127,7 @@ defmodule Pleroma.Web.MastodonAPI.WebsocketHandler do
     end
   end
 
-  defp streamer_socket(state) do
-    %{transport_pid: self(), assigns: state}
+  defp timer do
+    Process.send_after(self(), :tick, @tick)
   end
 end