Support OTP-19-rc2

rebar.config

@@ -13,7 +13,8 @@
 ]}.
 
 {erl_opts, [
-  debug_info
+  debug_info,
+  {platform_define, "19", 'UDP_HEADER'}
 ]}.
 
 {profiles, [

src/statsderl_server.erl

@@ -7,7 +7,7 @@
 ]).
 
 -record(state, {
-    header :: binary(),
+    header :: iodata(),
     socket :: inet:socket()
 }).
 
@@ -70,11 +70,9 @@ loop(State) ->
 udp_header(Hostname, Port, BaseKey) ->
     case statsderl_utils:getaddrs(Hostname) of
         {ok, {A, B, C, D}} ->
-            {ok, iolist_to_binary([
-                [((Port) bsr 8) band 16#ff, (Port) band 16#ff],
-                [A band 16#ff, B band 16#ff, C band 16#ff, D band 16#ff],
-                statsderl_utils:base_key(BaseKey)
-            ])};
+            Header = statsderl_udp:header({A, B, C, D}, Port),
+            BaseKey2 = statsderl_utils:base_key(BaseKey),
+            {ok, [Header, BaseKey2]};
         {error, Reason} ->
             {error, Reason}
     end.

src/statsderl_udp.erl

@@ -0,0 +1,44 @@
+-module(statsderl_udp).
+-include("statsderl.hrl").
+
+-compile(inline).
+-compile({inline_size, 512}).
+
+-export([
+    header/2,
+    send/3
+]).
+
+-define(INET_AF_INET, 1).
+-define(INT16(X), [((X) bsr 8) band 16#ff, (X) band 16#ff]).
+
+%% public
+-spec header(inet:ip_address(), inet:port_number()) -> iodata().
+
+-ifdef(UDP_HEADER).
+
+header(IP, Port) ->
+    [?INET_AF_INET, ?INT16(Port) | ip4_to_bytes(IP)].
+
+-else.
+
+header(IP, Port) ->
+    [?INT16(Port) | ip4_to_bytes(IP)].
+
+-endif.
+
+-spec send(inet:socket(), iodata(), iodata()) ->
+    ok | {error, term()}.
+
+send(Socket, Header, Data) ->
+    try
+        true = erlang:port_command(Socket, [Header, Data]),
+        ok
+    catch
+        Error:Reason ->
+            {error, {Error, Reason}}
+    end.
+
+%% private
+ip4_to_bytes({A, B, C, D}) ->
+    [A band 16#ff, B band 16#ff, C band 16#ff, D band 16#ff].