open conn in separate task

lib/pleroma/gun/conn.ex

@@ -6,6 +6,11 @@ defmodule Pleroma.Gun.Conn do
   @moduledoc """
   Struct for gun connection data
   """
+  alias Pleroma.Gun.API
+  alias Pleroma.Pool.Connections
+
+  require Logger
+
   @type gun_state :: :up | :down
   @type conn_state :: :active | :idle
 
@@ -26,4 +31,145 @@ defmodule Pleroma.Gun.Conn do
             last_reference: 0,
             crf: 1,
             retries: 0
+
+  @spec open(String.t() | URI.t(), atom(), keyword()) :: :ok | nil
+  def open(url, name, opts \\ [])
+  def open(url, name, opts) when is_binary(url), do: open(URI.parse(url), name, opts)
+
+  def open(%URI{} = uri, name, opts) do
+    pool_opts = Pleroma.Config.get([:connections_pool], [])
+
+    opts =
+      opts
+      |> Enum.into(%{})
+      |> Map.put_new(:retry, pool_opts[:retry] || 0)
+      |> Map.put_new(:retry_timeout, pool_opts[:retry_timeout] || 100)
+      |> Map.put_new(:await_up_timeout, pool_opts[:await_up_timeout] || 5_000)
+
+    key = "#{uri.scheme}:#{uri.host}:#{uri.port}"
+
+    Logger.debug("opening new connection #{Connections.compose_uri_log(uri)}")
+
+    conn_pid =
+      if Connections.count(name) < opts[:max_connection] do
+        do_open(uri, opts)
+      else
+        try_do_open(name, uri, opts)
+      end
+
+    if is_pid(conn_pid) do
+      conn = %Pleroma.Gun.Conn{
+        conn: conn_pid,
+        gun_state: :up,
+        conn_state: :active,
+        last_reference: :os.system_time(:second)
+      }
+
+      :ok = API.set_owner(conn_pid, Process.whereis(name))
+      Connections.add_conn(name, key, conn)
+    end
+  end
+
+  defp do_open(uri, %{proxy: {proxy_host, proxy_port}} = opts) do
+    connect_opts =
+      uri
+      |> destination_opts()
+      |> add_http2_opts(uri.scheme, Map.get(opts, :tls_opts, []))
+
+    with open_opts <- Map.delete(opts, :tls_opts),
+         {:ok, conn} <- API.open(proxy_host, proxy_port, open_opts),
+         {:ok, _} <- API.await_up(conn, opts[:await_up_timeout]),
+         stream <- API.connect(conn, connect_opts),
+         {:response, :fin, 200, _} <- API.await(conn, stream) do
+      conn
+    else
+      error ->
+        Logger.warn(
+          "Received error on opening connection with http proxy #{
+            Connections.compose_uri_log(uri)
+          } #{inspect(error)}"
+        )
+
+        nil
+    end
+  end
+
+  defp do_open(uri, %{proxy: {proxy_type, proxy_host, proxy_port}} = opts) do
+    version =
+      proxy_type
+      |> to_string()
+      |> String.last()
+      |> case do
+        "4" -> 4
+        _ -> 5
+      end
+
+    socks_opts =
+      uri
+      |> destination_opts()
+      |> add_http2_opts(uri.scheme, Map.get(opts, :tls_opts, []))
+      |> Map.put(:version, version)
+
+    opts =
+      opts
+      |> Map.put(:protocols, [:socks])
+      |> Map.put(:socks_opts, socks_opts)
+
+    with {:ok, conn} <- API.open(proxy_host, proxy_port, opts),
+         {:ok, _} <- API.await_up(conn, opts[:await_up_timeout]) do
+      conn
+    else
+      error ->
+        Logger.warn(
+          "Received error on opening connection with socks proxy #{
+            Connections.compose_uri_log(uri)
+          } #{inspect(error)}"
+        )
+
+        nil
+    end
+  end
+
+  defp do_open(%URI{host: host, port: port} = uri, opts) do
+    {_type, host} = Pleroma.HTTP.Adapter.domain_or_ip(host)
+
+    with {:ok, conn} <- API.open(host, port, opts),
+         {:ok, _} <- API.await_up(conn, opts[:await_up_timeout]) do
+      conn
+    else
+      error ->
+        Logger.warn(
+          "Received error on opening connection #{Connections.compose_uri_log(uri)} #{
+            inspect(error)
+          }"
+        )
+
+        nil
+    end
+  end
+
+  defp destination_opts(%URI{host: host, port: port}) do
+    {_type, host} = Pleroma.HTTP.Adapter.domain_or_ip(host)
+    %{host: host, port: port}
+  end
+
+  defp add_http2_opts(opts, "https", tls_opts) do
+    Map.merge(opts, %{protocols: [:http2], transport: :tls, tls_opts: tls_opts})
+  end
+
+  defp add_http2_opts(opts, _, _), do: opts
+
+  defp try_do_open(name, uri, opts) do
+    Logger.debug("try to open conn #{Connections.compose_uri_log(uri)}")
+
+    with [{close_key, least_used} | _conns] <-
+           Connections.get_unused_conns(name),
+         :ok <- Pleroma.Gun.API.close(least_used.conn) do
+      Connections.remove_conn(name, close_key)
+
+      do_open(uri, opts)
+    else
+      [] -> nil
+    end
+  end
 end