fix large bodies (from atomvm_httpd)

Signed-off-by: harmon25 <dougwright1@gmail.com>

Author: harmon25

src/gen_tcp_server.erl

@@ -47,6 +47,7 @@
     addr => any
 }).
 -define(DEFAULT_SOCKET_OPTIONS, #{}).
+-define(MAX_SEND_CHUNK, 2048).
 
 %%
 %% API
@@ -168,16 +169,7 @@ try_send(Socket, Packet) when is_binary(Packet) ->
         "Trying to send binary packet data to socket ~p.  Packet (or len): ~p", [
         Socket, case byte_size(Packet) < 32 of true -> Packet; _ -> byte_size(Packet) end
     ]),
-    case socket:send(Socket, Packet) of
-        ok ->
-            ?TRACE("sent.", []),
-            ok;
-        {ok, Rest} ->
-            ?TRACE("sent.  remaining: ~p", [Rest]),
-            try_send(Socket, Rest);
-        Error ->
-            io:format("Send failed due to error ~p~n", [Error])
-    end;
+    try_send_binary(Socket, Packet);
 try_send(Socket, Char) when is_integer(Char) ->
     %% TODO handle unicode
     ?TRACE("Sending char ~p as ~p", [Char, <<Char:8>>]),
@@ -196,6 +188,20 @@ try_send_iolist(Socket, [H | T]) ->
     try_send(Socket, H),
     try_send_iolist(Socket, T).
 
+try_send_binary(_Socket, <<>>) ->
+    ok;
+try_send_binary(Socket, Packet) when is_binary(Packet) ->
+    ChunkSize = erlang:min(byte_size(Packet), ?MAX_SEND_CHUNK),
+    <<Chunk:ChunkSize/binary, Rest/binary>> = Packet,
+    case socket:send(Socket, Chunk) of
+        ok ->
+            try_send_binary(Socket, Rest);
+        {ok, Remaining} ->
+            try_send_binary(Socket, <<Remaining/binary, Rest/binary>>);
+        Error ->
+            io:format("Send failed due to error ~p~n", [Error])
+    end.
+
 is_string([]) ->
     true;
 is_string([H | T]) when is_integer(H) ->

src/httpd.erl

@@ -570,21 +570,49 @@ create_error(StatusCode, Error) ->
 create_reply(StatusCode, ContentType, Reply) when is_list(ContentType) orelse is_binary(ContentType) ->
     create_reply(StatusCode, #{"Content-Type" => ContentType}, Reply);
 create_reply(StatusCode, Headers, Reply) when is_map(Headers) ->
+    ReplyLen = iolist_length(Reply),
+    HeadersWithLen = ensure_content_length(Headers, ReplyLen),
     [
         <<"HTTP/1.1 ">>, erlang:integer_to_binary(StatusCode), <<" ">>, moniker(StatusCode),
         <<"\r\n">>,
-        io_lib:format("Server: atomvm-~s\r\n", [get_version_str(erlang:system_info(atomvm_version))]),
-        to_headers_list(Headers),
+        io_lib:format("Server: atomvm-~s\r\n", [get_version_str(get_atomvm_version())]),
+        to_headers_list(HeadersWithLen),
         <<"\r\n">>,
         Reply
     ].
 
+%% @private
+ensure_content_length(Headers, ReplyLen) ->
+    LenBin = erlang:integer_to_binary(ReplyLen),
+    CleanHeaders = remove_content_length_header(Headers),
+    CleanHeaders#{<<"Content-Length">> => LenBin}.
+
+%% @private
+remove_content_length_header(Headers) ->
+    KeysToRemove = [
+        "Content-Length",
+        <<"Content-Length">>,
+        "content-length",
+        <<"content-length">>
+    ],
+    lists:foldl(fun(Key, Acc) -> maps:remove(Key, Acc) end, Headers, KeysToRemove).
+
 %% @private
 maybe_binary_to_string(Bin) when is_binary(Bin) ->
     erlang:binary_to_list(Bin);
 maybe_binary_to_string(Other) ->
     Other.
 
+%% @private
+iolist_length(Bin) when is_binary(Bin) ->
+    erlang:byte_size(Bin);
+iolist_length(Int) when is_integer(Int), Int >= 0, Int =< 255 ->
+    1;
+iolist_length([]) ->
+    0;
+iolist_length([H | T]) ->
+    iolist_length(H) + iolist_length(T).
+
 %% @private
 to_headers_list(Headers) ->
     [io_lib:format("~s: ~s\r\n", [maybe_binary_to_string(Key), maybe_binary_to_string(Value)]) || {Key, Value} <- maps:to_list(Headers)].
@@ -596,6 +624,14 @@ get_version_str(Version) when is_binary(Version) ->
 get_version_str(_) ->
     "unknown".
 
+get_atomvm_version() ->
+    case catch erlang:system_info(atomvm_version) of
+        {'EXIT', _} ->
+            undefined;
+        Version ->
+            Version
+    end.
+
 %% @private
 moniker(?OK) ->
     <<"OK">>;