%% Copyright (c) 2017-2023, Loïc Hoguin <[email protected]>
%%
%% Permission to use, copy, modify, and/or distribute this software for any
%% purpose with or without fee is hereby granted, provided that the above
%% copyright notice and this permission notice appear in all copies.
%%
%% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
%% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
%% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
%% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
%% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
%% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
%% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
-module(gun_sse_h).
-behavior(gun_content_handler).
-export([init/5]).
-export([handle/3]).
-record(state, {
reply_to :: pid(),
stream_ref :: reference(),
sse_state :: cow_sse:state()
}).
%% @todo In the future we want to allow different media types.
-spec init(pid(), reference(), _, cow_http:headers(), _)
-> {ok, #state{}} | disable.
init(ReplyTo, StreamRef, _, Headers, _) ->
case lists:keyfind(<<"content-type">>, 1, Headers) of
{_, ContentType} ->
case cow_http_hd:parse_content_type(ContentType) of
{<<"text">>, <<"event-stream">>, _Ignored} ->
{ok, #state{reply_to=ReplyTo, stream_ref=StreamRef,
sse_state=cow_sse:init()}};
_ ->
disable
end;
_ ->
disable
end.
-spec handle(_, binary(), State) -> {done, non_neg_integer(), State} when State::#state{}.
handle(IsFin, Data, State) ->
handle(IsFin, Data, State, 0).
handle(IsFin, Data, State=#state{reply_to=ReplyTo, stream_ref=StreamRef, sse_state=SSE0}, Flow) ->
case cow_sse:parse(Data, SSE0) of
{event, Event, SSE} ->
ReplyTo ! {gun_sse, self(), StreamRef, Event},
handle(IsFin, <<>>, State#state{sse_state=SSE}, Flow + 1);
{more, SSE} ->
Inc = case IsFin of
fin ->
ReplyTo ! {gun_sse, self(), StreamRef, fin},
1;
_ ->
0
end,
{done, Flow + Inc, State#state{sse_state=SSE}}
end.
