defmodule Pleroma.Gun.ConnectionPool do @registry __MODULE__ alias Pleroma.Gun.ConnectionPool.WorkerSupervisor def children do [ {Registry, keys: :unique, name: @registry}, Pleroma.Gun.ConnectionPool.WorkerSupervisor ] end def get_conn(uri, opts) do key = "#{uri.scheme}:#{uri.host}:#{uri.port}" case Registry.lookup(@registry, key) do # The key has already been registered, but connection is not up yet [{worker_pid, {nil, _used_by, _crf, _last_reference}}] -> get_gun_pid_from_worker(worker_pid) [{worker_pid, {gun_pid, _used_by, _crf, _last_reference}}] -> GenServer.cast(worker_pid, {:add_client, self(), false}) {:ok, gun_pid} [] -> # :gun.set_owner fails in :connected state for whatevever reason, # so we open the connection in the process directly and send it's pid back # We trust gun to handle timeouts by itself case WorkerSupervisor.start_worker([uri, key, opts, self()]) do {:ok, _worker_pid} -> receive do {:conn_pid, pid} -> {:ok, pid} end {:error, {:error, {:already_registered, worker_pid}}} -> get_gun_pid_from_worker(worker_pid) err -> err end end end defp get_gun_pid_from_worker(worker_pid) do # GenServer.call will block the process for timeout length if # the server crashes on startup (which will happen if gun fails to connect) # so instead we use cast + monitor ref = Process.monitor(worker_pid) GenServer.cast(worker_pid, {:add_client, self(), true}) receive do {:conn_pid, pid} -> {:ok, pid} {:DOWN, ^ref, :process, ^worker_pid, reason} -> reason end end def release_conn(conn_pid) do query_result = Registry.select(@registry, [ {{:_, :"$1", {:"$2", :_, :_, :_}}, [{:==, :"$2", conn_pid}], [:"$1"]} ]) case query_result do [worker_pid] -> GenServer.cast(worker_pid, {:remove_client, self()}) [] -> :ok end end end