%% Feel free to use, reuse and abuse the code in this file. %% @doc Streaming handler. -module(toppage_handler). -export([init/3]). -export([rest_init/2]). -export([content_types_provided/2]). -export([streaming_csv/2]). init(_Transport, _Req, _Table) -> {upgrade, protocol, cowboy_rest}. rest_init(Req, Table) -> {ok, Req, Table}. content_types_provided(Req, State) -> {[ {{<<"text">>, <<"csv">>, []}, streaming_csv} ], Req, State}. streaming_csv(Req, Table) -> {N, Req1} = cowboy_req:binding(v1, Req, 1), MS = [{{'$1', '$2', '$3'}, [{'==', '$2', N}], ['$$']}], {{stream, result_streamer(Table, MS)}, Req1, Table}. result_streamer(Table, MS) -> fun (Socket, Transport) -> send_records(Socket, Transport, ets:select(Table, MS, 1)) end. send_records(Socket, Transport, {[Rec], Cont}) -> timer:sleep(500), send_line(Socket, Transport, Rec), send_records(Socket, Transport, ets:select(Cont)); send_records(_Socket, _Transport, '$end_of_table') -> ok. send_line(Socket, Transport, [Key, V1, V2]) -> Transport:send(Socket, [Key, $,, integer_to_list(V1), $,, integer_to_list(V2), $\r, $\n]).