The issue was that we were calling erlang:hibernate before a
receive .. after .. end call. Erlang hibernates the process before
reaching the receive instruction and we therefore couldn't enter
the after clause when hibernating.
This is now fixed by using erlang:send_after instead and receiving
that message instead of using an after clause.
To this end we are formatting the header names just like OTP does
except we do it for names of up to 32 characters, as there are
widely used header names of more than 20 characters, the limit that
OTP follows currently. An example of such header name would be
Sec-Websocket-Version.
The formatting itself is fairly simple: an uppercase character at
the start and after dashes, everything else lowercase.
Also sends a message 'shoot' that can be received by the protocol
to make sure Cowboy has had enough time to fully initialize the
socket. This message should be received before any socket-related
operations are performed.
WebSocket request connections are now moved from the pool 'default'
to the pool 'websocket', meaning we can have a lot of running
WebSockets despite having a low 'max_connections' setting.
Improves the readability of websocket handler code by having
two functions: websocket_handle/3 handles the packets received
from the socket, removing the tuple construct that was otherwise
needed, so only websocket_handle(Data, Req, State) is needed now;
websocket_info/3 handles the messages that the websocket handler
process received, as websocket_info(Info, Req, State).
Both functions return values are handled identically by Cowboy
so nothing changes on that end.
This ensures that an error thrown in handler_terminate/4 will be
shown after the error from handler_call/6, in the expected order.
As we already call WebSocketHandler:terminate/3, this should
fix issue #23.
Fixes issue #31.
Recursion shouldn't happen in a single catch statement or inside
a try .. catch statement. The only safe construct for catching
exceptions and perform recursion when everything goes well is
to put the recursive call inside a try .. of .. catch construct
in the of .. catch block.
Otherwise the stack gets filled with exception-related information
since they can still be caught if we were to send them and unfold
the whole thing.
Thanks go to lpgauth for reporting the issue and people on IRC
for explaining the hows and whys.
Browsers get mad that the returned location address is not the same
as what they sent, since the :(80|443) is stripped.
Add a simple eunit test due to existing ct websockets tests not
covering this case.
Return {ok, Req, State, hibernate}
or {reply, Data, Req, State, hibernate} to hibernate the websocket
process and save up memory and CPU. You should hibernate processes
that will receive few messages. So probably most of them.
