Add ProvideRangeCallback tests using sendfile

And fix this case when multiple ranges are requested.

src/cowboy_rest.erl

@@ -1363,7 +1363,13 @@ set_ranged_body_callback(Req, State=#state{handler=Handler}, Callback) ->
 		%% this for non-bytes units they can always return a single range with a binary
 		%% content-range information.
 		{Ranges, Req2, State2} when length(Ranges) > 1 ->
-			set_multipart_ranged_body(Req2, State2, Ranges)
+			%% We have to check whether there are sendfile tuples in the
+			%% ranges to be sent. If there are we must use stream_reply.
+			HasSendfile = [] =/= [true || {_, {sendfile, _, _, _}} <- Ranges],
+			case HasSendfile of
+				true -> send_multipart_ranged_body(Req2, State2, Ranges);
+				false -> set_multipart_ranged_body(Req2, State2, Ranges)
+			end
 	end catch Class:{case_clause, no_call} ->
 		error_terminate(Req, State, Class, {error, {missing_callback, {Handler, Callback, 2}},
 			'A callback specified in ranges_provided/2 is not exported.'})

test/handlers/provide_range_callback_h.erl

@@ -43,11 +43,31 @@ get_text_plain(Req, State) ->
 get_text_plain_bytes(#{qs := <<"missing">>}, _) ->
 	ct_helper_error_h:ignore(cowboy_rest, set_ranged_body_callback, 3),
 	no_call;
+get_text_plain_bytes(Req=#{qs := <<"sendfile">>, range := {_, [{From=0, infinity}]}}, State) ->
+	Path = code:lib_dir(cowboy) ++ "/ebin/cowboy.app",
+	Size = filelib:file_size(Path),
+	{[{{From, Size - 1, Size}, {sendfile, From, Size, Path}}], Req, State};
 get_text_plain_bytes(Req=#{range := {_, [{From=0, infinity}]}}, State) ->
 	%% We send everything in one part.
 	Body = <<"This is ranged REST!">>,
 	Total = byte_size(Body),
 	{[{{From, Total - 1, Total}, Body}], Req, State};
+get_text_plain_bytes(Req=#{qs := <<"sendfile">>, range := {_, Range}}, State) ->
+	%% We check the range header we get and send everything hardcoded.
+	[
+		{50, 99},
+		{150, 199},
+		{250, 299},
+		-99
+	] = Range,
+	Path = code:lib_dir(cowboy) ++ "/ebin/cowboy.app",
+	Size = filelib:file_size(Path),
+	{[
+		{{50, 99, Size}, {sendfile, 50, 50, Path}},
+		{{150, 199, Size}, {sendfile, 150, 50, Path}},
+		{{250, 299, Size}, {sendfile, 250, 50, Path}},
+		{{Size - 99, Size - 1, Size}, {sendfile, Size - 99, 99, Path}}
+	], Req, State};
 get_text_plain_bytes(Req=#{range := {_, Range}}, State) ->
 	%% We check the range header we get and send everything hardcoded.
 	[

test/rest_handler_SUITE.erl

@@ -413,6 +413,30 @@ provide_range_callback(Config) ->
 	{ok, <<"This is ranged REST!">>} = gun:await_body(ConnPid, Ref),
 	ok.
 
+provide_range_callback_sendfile(Config) ->
+	doc("A successful request for a single range results in a "
+		"206 partial content response with content-range set. (RFC7233 4.1, RFC7233 4.2)"),
+	ConnPid = gun_open(Config),
+	Ref = gun:get(ConnPid, "/provide_range_callback?sendfile", [
+		{<<"accept-encoding">>, <<"gzip">>},
+		{<<"range">>, <<"bytes=0-">>}
+	]),
+	Path = code:lib_dir(cowboy) ++ "/ebin/cowboy.app",
+	Size = filelib:file_size(Path),
+	{ok, Body} = file:read_file(Path),
+	{response, nofin, 206, Headers} = gun:await(ConnPid, Ref),
+	{_, <<"bytes">>} = lists:keyfind(<<"accept-ranges">>, 1, Headers),
+	{_, ContentRange} = lists:keyfind(<<"content-range">>, 1, Headers),
+	ContentRange = iolist_to_binary([
+		<<"bytes 0-">>,
+		integer_to_binary(Size - 1),
+		<<"/">>,
+		integer_to_binary(Size)
+	]),
+	{_, <<"text/plain">>} = lists:keyfind(<<"content-type">>, 1, Headers),
+	{ok, Body} = gun:await_body(ConnPid, Ref),
+	ok.
+
 provide_range_callback_multipart(Config) ->
 	doc("A successful request for multiple ranges results in a "
 		"206 partial content response using the multipart/byteranges "
@@ -442,6 +466,46 @@ provide_range_callback_multipart(Config) ->
 	<<"ThisisrangedREST!">> = BodyAcc,
 	ok.
 
+provide_range_callback_multipart_sendfile(Config) ->
+	doc("A successful request for multiple ranges results in a "
+		"206 partial content response using the multipart/byteranges "
+		"content-type and the content-range not being set. The real "
+		"content-type and content-range of the parts can be found in "
+		"the multipart headers. (RFC7233 4.1, RFC7233 A)"),
+	ConnPid = gun_open(Config),
+	Ref = gun:get(ConnPid, "/provide_range_callback?sendfile", [
+		{<<"accept-encoding">>, <<"gzip">>},
+		%% This range selects a few random chunks of the file.
+		{<<"range">>, <<"bytes=50-99, 150-199, 250-299, -99">>}
+	]),
+	Path = code:lib_dir(cowboy) ++ "/ebin/cowboy.app",
+	Size = filelib:file_size(Path),
+	Skip = Size - 399,
+	{ok, <<
+		_:50/binary, Body1:50/binary,
+		_:50/binary, Body2:50/binary,
+		_:50/binary, Body3:50/binary,
+		_:Skip/binary, Body4/bits>>} = file:read_file(Path),
+	{response, nofin, 206, Headers} = gun:await(ConnPid, Ref),
+	{_, <<"bytes">>} = lists:keyfind(<<"accept-ranges">>, 1, Headers),
+	false = lists:keyfind(<<"content-range">>, 1, Headers),
+	{_, <<"multipart/byteranges; boundary=", Boundary/bits>>}
+		= lists:keyfind(<<"content-type">>, 1, Headers),
+	{ok, Body0} = gun:await_body(ConnPid, Ref),
+	Body = do_decode(Headers, Body0),
+	%% We will receive the ranges in the same order as requested.
+	{ContentRanges, BodyAcc} = do_provide_range_callback_multipart_body(Body, Boundary, [], <<>>),
+	LastFrom = 300 + Skip,
+	LastTo = Size - 1,
+	[
+		{bytes, 50, 99, Size},
+		{bytes, 150, 199, Size},
+		{bytes, 250, 299, Size},
+		{bytes, LastFrom, LastTo, Size}
+	] = ContentRanges,
+	BodyAcc = <<Body1/binary, Body2/binary, Body3/binary, Body4/binary>>,
+	ok.
+
 do_provide_range_callback_multipart_body(Rest, Boundary, ContentRangesAcc, BodyAcc) ->
 	case cow_multipart:parse_headers(Rest, Boundary) of
 		{ok, Headers, Rest1} ->