diff options
Diffstat (limited to 'examples/rest_stream_response/src')
5 files changed, 132 insertions, 0 deletions
diff --git a/examples/rest_stream_response/src/rest_stream_response.app.src b/examples/rest_stream_response/src/rest_stream_response.app.src new file mode 100644 index 0000000..4a458b8 --- /dev/null +++ b/examples/rest_stream_response/src/rest_stream_response.app.src @@ -0,0 +1,15 @@ +%% Feel free to use, reuse and abuse the code in this file. + +{application, rest_stream_response, [ + {description, "Cowboy REST with streaming."}, + {vsn, "1"}, + {modules, []}, + {registered, []}, + {applications, [ + kernel, + stdlib, + cowboy + ]}, + {mod, {rest_stream_response_app, []}}, + {env, []} +]}. diff --git a/examples/rest_stream_response/src/rest_stream_response.erl b/examples/rest_stream_response/src/rest_stream_response.erl new file mode 100644 index 0000000..ef24309 --- /dev/null +++ b/examples/rest_stream_response/src/rest_stream_response.erl @@ -0,0 +1,14 @@ +%% Feel free to use, reuse and abuse the code in this file. + +-module(rest_stream_response). + +%% API. +-export([start/0]). + +%% API. + +start() -> + ok = application:start(crypto), + ok = application:start(ranch), + ok = application:start(cowboy), + ok = application:start(rest_stream_response). diff --git a/examples/rest_stream_response/src/rest_stream_response_app.erl b/examples/rest_stream_response/src/rest_stream_response_app.erl new file mode 100644 index 0000000..a382d29 --- /dev/null +++ b/examples/rest_stream_response/src/rest_stream_response_app.erl @@ -0,0 +1,38 @@ +%% Feel free to use, reuse and abuse the code in this file. + +%% @private +-module(rest_stream_response_app). +-behaviour(application). + +%% API. +-export([start/2]). +-export([stop/1]). + +%% API. + +start(_Type, _Args) -> + Table = ets:new(stream_tab, []), + generate_rows(Table, 1000), + Dispatch = cowboy_router:compile([ + {'_', [ + {"/[:v1]", [{v1, int}], toppage_handler, Table} + ]} + ]), + {ok, _} = cowboy:start_http(http, 100, [{port, 8080}], [ + {env, [{dispatch, Dispatch}]} + ]), + rest_stream_response_sup:start_link(). + +stop(_State) -> + ok. + +generate_rows(_Table, 0) -> ok; +generate_rows(Table, N) -> + ets:insert(Table, {key(), val(), val()}), + generate_rows(Table, N - 1). + +key() -> key(10). +key(N) -> key(<< (random:uniform(26) - 1) >>, N - 1). +key(Acc, 0) -> binary_part(base64:encode(Acc), 0, 8); +key(Acc, N) -> key(<< Acc/binary, (random:uniform(26) - 1) >>, N - 1). +val() -> random:uniform(50). diff --git a/examples/rest_stream_response/src/rest_stream_response_sup.erl b/examples/rest_stream_response/src/rest_stream_response_sup.erl new file mode 100644 index 0000000..73142d4 --- /dev/null +++ b/examples/rest_stream_response/src/rest_stream_response_sup.erl @@ -0,0 +1,23 @@ +%% Feel free to use, reuse and abuse the code in this file. + +%% @private +-module(rest_stream_response_sup). +-behaviour(supervisor). + +%% API. +-export([start_link/0]). + +%% supervisor. +-export([init/1]). + +%% API. + +-spec start_link() -> {ok, pid()}. +start_link() -> + supervisor:start_link({local, ?MODULE}, ?MODULE, []). + +%% supervisor. + +init([]) -> + Procs = [], + {ok, {{one_for_one, 10, 10}, Procs}}. diff --git a/examples/rest_stream_response/src/toppage_handler.erl b/examples/rest_stream_response/src/toppage_handler.erl new file mode 100644 index 0000000..5052038 --- /dev/null +++ b/examples/rest_stream_response/src/toppage_handler.erl @@ -0,0 +1,42 @@ +%% 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]). |