Add chunked transfer encoding support and rework the body reading API

Introduces 3 low level functions and updates the existing higher
levels functions. The new primitives are has_body/1, body_length/1
and stream_body/1. In addition to that, a helper function
init_stream/4 has been added.

Streaming a body implies to decode the Transfer-Encoding and
Content-Encoding used for the body. By default, Cowboy will try
to figure out what was used and decode them properly. You can
override this if you want to disable this behavior or simply
support more encodings by calling the init_stream/4 function
before you start streaming the body.

1 files changed, 9 insertions, 3 deletions

diff --git a/src/cowboy_http_websocket.erl b/src/cowboy_http_websocket.erl
index f08405b..bc28712 100644
--- a/src/cowboy_http_websocket.erl
+++ b/src/cowboy_http_websocket.erl
@@ -175,12 +175,18 @@ websocket_handshake(State=#state{version=0, origin=Origin,
 	%% We replied with a proper response. Proxies should be happy enough,
 	%% we can now read the 8 last bytes of the challenge keys and send
 	%% the challenge response directly to the socket.
-	case cowboy_http_req:body(8, Req2) of
-		{ok, Key3, Req3} ->
+	%%
+	%% We use a trick here to read exactly 8 bytes of the body regardless
+	%% of what's in the buffer.
+	{ok, Req3} = cowboy_http_req:init_stream(
+		fun cowboy_http:te_identity/2, {0, 8},
+		fun cowboy_http:ce_identity/1, Req2),
+	case cowboy_http_req:body(Req3) of
+		{ok, Key3, Req4} ->
 			Challenge = hixie76_challenge(Key1, Key2, Key3),
 			Transport:send(Socket, Challenge),
 			handler_before_loop(State#state{messages=Transport:messages()},
-				Req3, HandlerState, <<>>);
+				Req4, HandlerState, <<>>);
 		_Any ->
 			closed %% If an error happened reading the body, stop there.
 	end;