%% Copyright (c) 2011, Loïc Hoguin %% %% 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. %% @doc Date and time related functions. %% %% While a gen_server process runs in the background to update %% the cache of formatted dates every second, all API calls are %% local and directly read from the ETS cache table, providing %% fast time and date computations. -module(cowboy_clock). -behaviour(gen_server). -export([start_link/0, stop/0, rfc1123/0]). %% API. -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]). %% gen_server. %% @todo Use calendar types whenever they get exported. -type year() :: non_neg_integer(). -type month() :: 1..12. -type day() :: 1..31. -type hour() :: 0..23. -type minute() :: 0..59. -type second() :: 0..59. -type daynum() :: 1..7. -type date() :: {year(), month(), day()}. -type time() :: {hour(), minute(), second()}. -type datetime() :: {date(), time()}. -record(state, { universaltime = undefined :: undefined | datetime(), rfc1123 = <<>> :: binary(), tref = undefined :: undefined | timer:tref() }). -define(SERVER, ?MODULE). -define(TABLE, ?MODULE). -include_lib("eunit/include/eunit.hrl"). %% API. %% @private -spec start_link() -> {ok, pid()}. start_link() -> gen_server:start_link({local, ?SERVER}, ?MODULE, [], []). %% @private -spec stop() -> stopped. stop() -> gen_server:call(?SERVER, stop). %% @doc Return the current date and time formatted according to RFC-1123. %% %% This format is used in the 'Date' header sent with HTTP responses. -spec rfc1123() -> binary(). rfc1123() -> ets:lookup_element(?TABLE, rfc1123, 2). %% gen_server. %% @private -spec init([]) -> {ok, #state{}}. init([]) -> ?TABLE = ets:new(?TABLE, [set, protected, named_table, {read_concurrency, true}]), T = erlang:universaltime(), B = update_rfc1123(<<>>, undefined, T), {ok, TRef} = timer:send_interval(1000, update), ets:insert(?TABLE, {rfc1123, B}), {ok, #state{universaltime=T, rfc1123=B, tref=TRef}}. %% @private -spec handle_call(_, _, State) -> {reply, ignored, State} | {stop, normal, stopped, State}. handle_call(stop, _From, State=#state{tref=TRef}) -> {ok, cancel} = timer:cancel(TRef), {stop, normal, stopped, State}; handle_call(_Request, _From, State) -> {reply, ignored, State}. %% @private -spec handle_cast(_, State) -> {noreply, State}. handle_cast(_Msg, State) -> {noreply, State}. %% @private -spec handle_info(_, State) -> {noreply, State}. handle_info(update, #state{universaltime=Prev, rfc1123=B1, tref=TRef}) -> T = erlang:universaltime(), B2 = update_rfc1123(B1, Prev, T), ets:insert(?TABLE, {rfc1123, B2}), {noreply, #state{universaltime=T, rfc1123=B2, tref=TRef}}; handle_info(_Info, State) -> {noreply, State}. %% @private -spec terminate(_, _) -> ok. terminate(_Reason, _State) -> ok. %% @private -spec code_change(_, State, _) -> {ok, State}. code_change(_OldVsn, State, _Extra) -> {ok, State}. %% Internal. -spec update_rfc1123(binary(), undefined | datetime(), datetime()) -> binary(). update_rfc1123(Bin, Now, Now) -> Bin; update_rfc1123(<< Keep:23/binary, _/bits >>, {Date, {H, M, _}}, {Date, {H, M, S}}) -> << Keep/binary, (pad_int(S))/binary, " GMT" >>; update_rfc1123(<< Keep:20/binary, _/bits >>, {Date, {H, _, _}}, {Date, {H, M, S}}) -> << Keep/binary, (pad_int(M))/binary, $:, (pad_int(S))/binary, " GMT" >>; update_rfc1123(<< Keep:17/binary, _/bits >>, {Date, _}, {Date, {H, M, S}}) -> << Keep/binary, (pad_int(H))/binary, $:, (pad_int(M))/binary, $:, (pad_int(S))/binary, " GMT" >>; update_rfc1123(<< _:7/binary, Keep:10/binary, _/bits >>, {{Y, Mo, _}, _}, {Date = {Y, Mo, D}, {H, M, S}}) -> Wday = calendar:day_of_the_week(Date), << (weekday(Wday))/binary, ", ", (pad_int(D))/binary, Keep/binary, (pad_int(H))/binary, $:, (pad_int(M))/binary, $:, (pad_int(S))/binary, " GMT" >>; update_rfc1123(<< _:11/binary, Keep:6/binary, _/bits >>, {{Y, _, _}, _}, {Date = {Y, Mo, D}, {H, M, S}}) -> Wday = calendar:day_of_the_week(Date), << (weekday(Wday))/binary, ", ", (pad_int(D))/binary, " ", (month(Mo))/binary, Keep/binary, (pad_int(H))/binary, $:, (pad_int(M))/binary, $:, (pad_int(S))/binary, " GMT" >>; update_rfc1123(_, _, {Date = {Y, Mo, D}, {H, M, S}}) -> Wday = calendar:day_of_the_week(Date), << (weekday(Wday))/binary, ", ", (pad_int(D))/binary, " ", (month(Mo))/binary, " ", (list_to_binary(integer_to_list(Y)))/binary, " ", (pad_int(H))/binary, $:, (pad_int(M))/binary, $:, (pad_int(S))/binary, " GMT" >>. %% Following suggestion by MononcQc on #erlounge. -spec pad_int(0..59) -> binary(). pad_int(X) when X < 10 -> << $0, ($0 + X) >>; pad_int(X) -> list_to_binary(integer_to_list(X)). -spec weekday(daynum()) -> <<_:24>>. weekday(1) -> <<"Mon">>; weekday(2) -> <<"Tue">>; weekday(3) -> <<"Wed">>; weekday(4) -> <<"Thu">>; weekday(5) -> <<"Fri">>; weekday(6) -> <<"Sat">>; weekday(7) -> <<"Sun">>. -spec month(month()) -> <<_:24>>. month( 1) -> <<"Jan">>; month( 2) -> <<"Feb">>; month( 3) -> <<"Mar">>; month( 4) -> <<"Apr">>; month( 5) -> <<"May">>; month( 6) -> <<"Jun">>; month( 7) -> <<"Jul">>; month( 8) -> <<"Aug">>; month( 9) -> <<"Sep">>; month(10) -> <<"Oct">>; month(11) -> <<"Nov">>; month(12) -> <<"Dec">>. %% Tests. -ifdef(TEST). update_rfc1123_test_() -> Tests = [ {<<"Sat, 14 May 2011 14:25:33 GMT">>, undefined, {{2011, 5, 14}, {14, 25, 33}}, <<>>}, {<<"Sat, 14 May 2011 14:25:33 GMT">>, {{2011, 5, 14}, {14, 25, 33}}, {{2011, 5, 14}, {14, 25, 33}}, <<"Sat, 14 May 2011 14:25:33 GMT">>}, {<<"Sat, 14 May 2011 14:25:34 GMT">>, {{2011, 5, 14}, {14, 25, 33}}, {{2011, 5, 14}, {14, 25, 34}}, <<"Sat, 14 May 2011 14:25:33 GMT">>}, {<<"Sat, 14 May 2011 14:26:00 GMT">>, {{2011, 5, 14}, {14, 25, 59}}, {{2011, 5, 14}, {14, 26, 0}}, <<"Sat, 14 May 2011 14:25:59 GMT">>}, {<<"Sat, 14 May 2011 15:00:00 GMT">>, {{2011, 5, 14}, {14, 59, 59}}, {{2011, 5, 14}, {15, 0, 0}}, <<"Sat, 14 May 2011 14:59:59 GMT">>}, {<<"Sun, 15 May 2011 00:00:00 GMT">>, {{2011, 5, 14}, {23, 59, 59}}, {{2011, 5, 15}, { 0, 0, 0}}, <<"Sat, 14 May 2011 23:59:59 GMT">>}, {<<"Wed, 01 Jun 2011 00:00:00 GMT">>, {{2011, 5, 31}, {23, 59, 59}}, {{2011, 6, 1}, { 0, 0, 0}}, <<"Tue, 31 May 2011 23:59:59 GMT">>}, {<<"Sun, 01 Jan 2012 00:00:00 GMT">>, {{2011, 5, 31}, {23, 59, 59}}, {{2012, 1, 1}, { 0, 0, 0}}, <<"Sat, 31 Dec 2011 23:59:59 GMT">>} ], [{R, fun() -> R = update_rfc1123(B, P, N) end} || {R, P, N, B} <- Tests]. pad_int_test_() -> Tests = [ { 0, <<"00">>}, { 1, <<"01">>}, { 2, <<"02">>}, { 3, <<"03">>}, { 4, <<"04">>}, { 5, <<"05">>}, { 6, <<"06">>}, { 7, <<"07">>}, { 8, <<"08">>}, { 9, <<"09">>}, {10, <<"10">>}, {11, <<"11">>}, {12, <<"12">>}, {13, <<"13">>}, {14, <<"14">>}, {15, <<"15">>}, {16, <<"16">>}, {17, <<"17">>}, {18, <<"18">>}, {19, <<"19">>}, {20, <<"20">>}, {21, <<"21">>}, {22, <<"22">>}, {23, <<"23">>}, {24, <<"24">>}, {25, <<"25">>}, {26, <<"26">>}, {27, <<"27">>}, {28, <<"28">>}, {29, <<"29">>}, {30, <<"30">>}, {31, <<"31">>}, {32, <<"32">>}, {33, <<"33">>}, {34, <<"34">>}, {35, <<"35">>}, {36, <<"36">>}, {37, <<"37">>}, {38, <<"38">>}, {39, <<"39">>}, {40, <<"40">>}, {41, <<"41">>}, {42, <<"42">>}, {43, <<"43">>}, {44, <<"44">>}, {45, <<"45">>}, {46, <<"46">>}, {47, <<"47">>}, {48, <<"48">>}, {49, <<"49">>}, {50, <<"50">>}, {51, <<"51">>}, {52, <<"52">>}, {53, <<"53">>}, {54, <<"54">>}, {55, <<"55">>}, {56, <<"56">>}, {57, <<"57">>}, {58, <<"58">>}, {59, <<"59">>} ], [{I, fun() -> O = pad_int(I) end} || {I, O} <- Tests]. -endif.