ratelimiter

lib/tir_inna_noc/imageboard.ex

@@ -5,16 +5,24 @@ defmodule TirInnaNoc.Imageboard do
   #plug Tesla.Middleware.Headers, [{"authorization", "token xyz"}]
   plug Tesla.Middleware.JSON
 
+  def wget(uri) do
+    if GenServer.call(:ratelimiter, :activate) == :goahead do
+      get(uri)
+    else
+      Process.sleep(1000)
+      wget(uri)
+    end
+  end
   def boards() do
-    get("/boards.json")
+    wget("/boards.json")
   end
   def threads(board) do
-    get("/"<>board<>"/threads.json")
+    wget("/"<>board<>"/threads.json")
   end
   def thread(board, id) do
-    get("/"<>board<>"/thread/"<>to_string(id)<>".json")
+    wget("/"<>board<>"/thread/"<>to_string(id)<>".json")
   end
   def catalog(board) do
-    get("/"<>board<>"/catalog.json")
+    wget("/"<>board<>"/catalog.json")
   end
 end

lib/tir_inna_noc/rate.ex

@@ -0,0 +1,23 @@
+defmodule TirInnaNoc.Rate do
+  use GenServer
+
+  def start_link(last_activity) do
+    GenServer.start_link(__MODULE__, last_activity, name: :ratelimiter)
+  end
+
+  @impl true
+  def init(last_activity) do
+    last_activity = :os.system_time(:millisecond)
+    {:ok, last_activity}
+  end
+
+  @impl true
+  def handle_call(:activate, _, last_activity) do
+    if :os.system_time(:millisecond) - last_activity > 10_000 do
+      last_activity = :os.system_time(:millisecond)
+      {:reply, :goahead, last_activity}
+    else
+      {:reply, :defer, last_activity}
+    end
+  end
+end

lib/tir_inna_noc/sup.ex

@@ -9,6 +9,7 @@ defmodule TirInnaNoc.Sup do
   def init(:ok) do
     children = [
       {TirInnaNoc.Db, [nil]},
+      {TirInnaNoc.Rate, [nil]},
       {DynamicSupervisor, strategy: :one_for_one, name: MerlinSupervisor},
       {TirInnaNoc.Merlin, [nil]}
     ]