Add sendfile support to cowboy_req:stream_body

It is now possible to stream one or more sendfile tuples.
A simple example of what can now be done would be for
example to build a tar file on the fly using the sendfile
syscall for sending the files, or to support Range requests
with more than one range with the sendfile syscall.

When using cowboy_compress_h unfortunately we have to read
the file in order to send it. More options will be added
at a later time to make sure users don't read too much
into memory. This is a new feature however so existing
code is not affected.

Also rework cowboy_http's data sending to be flatter.

1 files changed, 0 insertions, 6 deletions

diff --git a/src/cowboy_http2.erl b/src/cowboy_http2.erl
index d461595..fc1a3a0 100644
--- a/src/cowboy_http2.erl
+++ b/src/cowboy_http2.erl
@@ -510,12 +510,6 @@ commands(State0, StreamID, [{data, IsFin, Data}|Tail]) ->
 commands(State0, StreamID, [{trailers, Trailers}|Tail]) ->
 	State = maybe_send_data(State0, StreamID, fin, {trailers, maps:to_list(Trailers)}),
 	commands(State, StreamID, Tail);
-%% Send a file.
-%% @todo Add the sendfile command.
-%commands(State0, Stream0=#stream{local=nofin},
-%		[{sendfile, IsFin, Offset, Bytes, Path}|Tail]) ->
-%	{State, Stream} = maybe_send_data(State0, Stream0, IsFin, {sendfile, Offset, Bytes, Path}),
-%	commands(State, Stream, Tail);
 %% Send a push promise.
 %%
 %% @todo Responses sent as a result of a push_promise request