Optimize HTTP/2 request creation

lib/mint/http2.ex

@@ -170,6 +170,7 @@ defmodule Mint.HTTP2 do
     :hostname,
     :port,
     :scheme,
+    :authority,
 
     # Connection state (open, closed, and so on).
     :state,
@@ -974,10 +975,18 @@ defmodule Mint.HTTP2 do
         ) :: {:ok, t()} | {:error, Types.error()}
   def initiate(scheme, socket, hostname, port, opts) do
     transport = scheme_to_transport(scheme)
+    scheme_string = Atom.to_string(scheme)
     mode = Keyword.get(opts, :mode, :active)
     log? = Keyword.get(opts, :log, false)
     client_settings_params = Keyword.get(opts, :client_settings, [])
     validate_client_settings!(client_settings_params)
+    # If the port is the default for the scheme, don't add it to the :authority pseudo-header
+    authority =
+      if URI.default_port(scheme_string) == port do
+        hostname
+      else
+        "#{hostname}:#{port}"
+      end
 
     unless mode in [:active, :passive] do
       raise ArgumentError,
@@ -992,10 +1001,11 @@ defmodule Mint.HTTP2 do
     conn = %__MODULE__{
       hostname: hostname,
       port: port,
+      authority: authority,
       transport: scheme_to_transport(scheme),
       socket: socket,
       mode: mode,
-      scheme: Atom.to_string(scheme),
+      scheme: scheme_string,
       state: :handshaking,
       log: log?
     }
@@ -1355,23 +1365,37 @@ defmodule Mint.HTTP2 do
   end
 
   defp add_pseudo_headers(headers, conn, method, path) do
-    if String.upcase(method) == "CONNECT" do
+    if is_method?(method, ~c"CONNECT") do
       [
         {":method", method},
-        {":authority", authority_pseudo_header(conn.scheme, conn.port, conn.hostname)}
+        {":authority", conn.authority}
         | headers
       ]
     else
       [
         {":method", method},
         {":path", path},
         {":scheme", conn.scheme},
-        {":authority", authority_pseudo_header(conn.scheme, conn.port, conn.hostname)}
+        {":authority", conn.authority}
         | headers
       ]
     end
   end
 
+  @spec is_method?(proposed :: binary(), method :: charlist()) :: boolean()
+  defp is_method?(<<>>, []), do: true
+
+  defp is_method?(<<char, rest_bin::binary>>, [char | rest_list]) do
+    is_method?(rest_bin, rest_list)
+  end
+
+  defp is_method?(<<lower_char, rest_bin::binary>>, [char | rest_list])
+       when lower_char >= ?a and lower_char <= ?z and lower_char - 32 == char do
+    is_method?(rest_bin, rest_list)
+  end
+
+  defp is_method?(_proposed, _method), do: false
+
   defp sort_pseudo_headers_to_front(headers) do
     Enum.sort_by(headers, fn {key, _value} ->
       not String.starts_with?(key, ":")
@@ -1719,15 +1743,6 @@ defmodule Mint.HTTP2 do
     end
   end
 
-  # If the port is the default for the scheme, don't add it to the :authority pseudo-header
-  defp authority_pseudo_header(scheme, port, hostname) do
-    if URI.default_port(scheme) == port do
-      hostname
-    else
-      "#{hostname}:#{port}"
-    end
-  end
-
   defp join_cookie_headers(headers) do
     # If we have 0 or 1 Cookie headers, we just use the old list of headers.
     case Enum.split_with(headers, fn {name, _value} -> Util.downcase_ascii(name) == "cookie" end) do

test/mint/http2/conn_test.exs

@@ -22,6 +22,7 @@ defmodule Mint.HTTP2Test do
   @server_pdict_key {__MODULE__, :http2_test_server}
 
   setup :start_server_async
+  setup :maybe_change_default_scheme_port
   setup :start_connection
   setup :maybe_set_transport_mock
 
@@ -841,29 +842,21 @@ defmodule Mint.HTTP2Test do
       assert HTTP2.open?(conn)
     end
 
+    @tag :with_overridden_default_port
     test ":authority pseudo-header does not include port if it is the scheme's default",
          %{conn: conn} do
-      default_https_port = URI.default_port("https")
-
-      try do
-        # Override default https port for this test
-        URI.default_port("https", conn.port)
-
-        {conn, _ref} = open_request(conn)
+      {conn, _ref} = open_request(conn)
 
-        assert_recv_frames [headers(hbf: hbf)]
+      assert_recv_frames [headers(hbf: hbf)]
 
-        assert {":authority", authority} =
-                 hbf
-                 |> server_decode_headers()
-                 |> List.keyfind(":authority", 0)
+      assert {":authority", authority} =
+               hbf
+               |> server_decode_headers()
+               |> List.keyfind(":authority", 0)
 
-        assert authority == conn.hostname
+      assert authority == conn.hostname
 
-        assert HTTP2.open?(conn)
-      after
-        URI.default_port("https", default_https_port)
-      end
+      assert HTTP2.open?(conn)
     end
 
     test "when there's a request body, the content-length header is passed if not present",
@@ -2374,6 +2367,23 @@ defmodule Mint.HTTP2Test do
     %{}
   end
 
+  defp maybe_change_default_scheme_port(%{
+         server_port: server_port,
+         with_overridden_default_port: _
+       }) do
+    default_https_port = URI.default_port("https")
+
+    on_exit(fn -> URI.default_port("https", default_https_port) end)
+
+    :ok = URI.default_port("https", server_port)
+
+    %{}
+  end
+
+  defp maybe_change_default_scheme_port(_context) do
+    %{}
+  end
+
   defp recv_next_frames(n) do
     server = Process.get(@server_pdict_key)
     TestServer.recv_next_frames(server, n)