%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1997-2009. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
%%
-module(time_SUITE).
%% "Time is on my side." -- The Rolling Stones
%% Tests the BIFs:
%% erlang:localtime_to_universaltime/1
%% erlang:universaltime_to_localtime/1
%% date/0
%% time/0
%% now/0
%%
-export([all/1, univ_to_local/1, local_to_univ/1,
bad_univ_to_local/1, bad_local_to_univ/1,
consistency/1,
now/1, now_unique/1, now_update/1, timestamp/1]).
-include("test_server.hrl").
-export([linear_time/1]).
%% The following defines the timezone in which the test is run.
%% It is interpreted as the number of hours to be added to UTC
%% to obtain the local time. The number will be positive east
%% of Greenwhich, negative west of Greenwhich.
%%
%% Allowable range is -12 through 11.
-define(timezone, 1).
%% Similarly to timezone, but the difference when Daylight Saving Time
%% is in use. [Same range.]
-define(dst_timezone, 2).
all(suite) -> [univ_to_local, local_to_univ,
bad_univ_to_local, bad_local_to_univ, consistency, now, timestamp].
%% Tests conversion from univeral to local time.
univ_to_local(Config) when is_list(Config) ->
?line test_univ_to_local(test_data()).
test_univ_to_local([{Utc, Local}|Rest]) ->
?line io:format("Testing ~p => ~p~n", [Local, Utc]),
?line Local = erlang:universaltime_to_localtime(Utc),
?line test_univ_to_local(Rest);
test_univ_to_local([]) ->
ok.
%% Tests conversion from local to universal time.
local_to_univ(Config) when is_list(Config) ->
?line test_local_to_univ(test_data()).
test_local_to_univ([{Utc, Local}|Rest]) ->
?line io:format("Testing ~p => ~p~n", [Utc, Local]),
?line Utc = erlang:localtime_to_universaltime(Local),
?line test_local_to_univ(Rest);
test_local_to_univ([]) ->
ok.
%% Test bad arguments to erlang:universaltime_to_localtime; should
%% generate a badarg.
bad_univ_to_local(Config) when is_list(Config) ->
?line bad_test_univ_to_local(bad_dates()).
bad_test_univ_to_local([Utc|Rest]) ->
?line io:format("Testing ~p~n", [Utc]),
?line case catch erlang:universaltime_to_localtime(Utc) of
{'EXIT', {badarg, _}} -> bad_test_univ_to_local(Rest)
end;
bad_test_univ_to_local([]) ->
ok.
%% Test bad arguments to erlang:localtime_to_universaltime/1; should
%% generate a badarg.
bad_local_to_univ(Config) when is_list(Config) ->
?line bad_test_local_to_univ(bad_dates()).
bad_test_local_to_univ([Local|Rest]) ->
?line io:format("Testing ~p~n", [Local]),
?line case catch erlang:localtime_to_universaltime(Local) of
{'EXIT', {badarg, _}} -> bad_test_local_to_univ(Rest)
end;
bad_test_local_to_univ([]) ->
ok.
%% Test that the the different time functions return
%% consistent results. (See the test case for assumptions
%% and limitations.)
consistency(Config) when is_list(Config) ->
%% Test the following equations:
%% date() & time() == erlang:localtime()
%% erlang:universaltime() + timezone == erlang:localtime()
%%
%% Assumptions:
%% Middle-European time zone, EU rules for daylight-saving time.
%%
%% Limitations:
%% Localtime and universaltime must be in the same month.
%% Daylight-saving calculations are incorrect from the last
%% Sunday of March and October to the end of the month.
?line ok = compare_date_time_and_localtime(16),
?line ok = compare_local_and_universal(16).
compare_date_time_and_localtime(Times) when Times > 0 ->
?line {Year, Mon, Day} = date(),
?line {Hour, Min, Sec} = time(),
?line case erlang:localtime() of
{{Year, Mon, Day}, {Hour, Min, Sec}} -> ok;
_ -> compare_date_time_and_localtime(Times-1)
end;
compare_date_time_and_localtime(0) ->
error.
compare_local_and_universal(Times) when Times > 0 ->
case compare(erlang:universaltime(), erlang:localtime()) of
true -> ok;
false -> compare_local_and_universal(Times-1)
end;
compare_local_and_universal(0) ->
error.
compare(Utc0, Local) ->
io:format("local = ~p, utc = ~p", [Local, Utc0]),
Utc = linear_time(Utc0)+effective_timezone(Utc0)*3600,
case linear_time(Local) of
Utc -> true;
Other ->
io:format("Failed: local = ~p, utc = ~p~n",
[Other, Utc]),
false
end.
%% This function converts a date and time to a linear time.
%% Two linear times can be subtracted to give their difference
%% in seconds.
%%
%% XXX Limitations: The length of months and leap years are not
%% taken into account; thus a comparision of dates is only
%% valid if they are in the SAME month.
linear_time({{Year, Mon, Day}, {Hour, Min, Sec}}) ->
86400*(366*Year + 31*(Mon-1) + (Day-1)) +
3600*Hour + 60*Min + Sec.
%% This functions returns either the normal timezone or the
%% the DST timezone, depending on the given UTC time.
%%
%% XXX This function uses an approximation of the EU rule for
%% daylight saving time. This function will fail in the
%% following intervals: After the last Sunday in March upto
%% the end of March, and after the last Sunday in October
%% upto the end of October.
effective_timezone(Time) ->
case os:type() of
{unix,_} ->
case os:cmd("date '+%Z'") of
"SAST"++_ ->
2;
_ ->
effective_timezone1(Time)
end;
_ ->
effective_timezone1(Time)
end.
effective_timezone1({{_Year,Mon,_Day}, _}) when Mon < 4 ->
?timezone;
effective_timezone1({{_Year,Mon,_Day}, _}) when Mon > 10 ->
?timezone;
effective_timezone1(_) ->
?dst_timezone.
%% Test (the bif) os:timestamp/0, which is something quite like, but not
%% similar to erlang:now...
timestamp(suite) ->
[];
timestamp(doc) ->
["Test that os:timestamp works."];
timestamp(Config) when is_list(Config) ->
repeating_timestamp_check(100000).
repeating_timestamp_check(0) ->
ok;
repeating_timestamp_check(N) ->
{A,B,C} = TS = os:timestamp(),
if
is_integer(A),
is_integer(B),
is_integer(C),
B < 1000000,
C < 1000000 ->
ok;
true ->
test_server:fail(
lists:flatten(
io_lib:format("Strange return from os:timestamp/0 ~w~n",[TS])))
end,
%% I assume the now and timestamp should not differ more than 1 hour,
%% which is safe assuming the system has not had a large time-warp
%% during the testrun...
Secs = A*1000000+B+round(C/1000000),
{NA,NB,NC} = erlang:now(),
NSecs = NA*1000000+NB+round(NC/1000000),
case Secs - NSecs of
TooLarge when TooLarge > 3600 ->
test_server:fail(
lists:flatten(
io_lib:format("os:timestamp/0 is ~w s more than erlang:now/0",
[TooLarge])));
TooSmall when TooSmall < -3600 ->
test_server:fail(
lists:flatten(
io_lib:format("os:timestamp/0 is ~w s less than erlang:now/0",
[-TooSmall])));
_ ->
ok
end,
repeating_timestamp_check(N-1).
%% Test now/0.
now(suite) -> [now_unique, now_update].
%% Tests that successive calls to now/0 returns different values.
%% Also returns a comment string with the median difference between
%% times (in microseconds).
now_unique(Config) when is_list(Config) ->
?line now_unique(1000, now(), []),
?line fast_now_unique(100000, now()).
now_unique(N, Previous, Result) when N > 0 ->
?line case now() of
Previous ->
test_server:fail("now/0 returned the same value twice");
New ->
now_unique(N-1, New, [New|Result])
end;
now_unique(0, _, [Then|Rest]) ->
?line now_calc_increment(Rest, microsecs(Then), []).
now_calc_increment([Then|Rest], Previous, _Result) ->
?line This = microsecs(Then),
?line now_calc_increment(Rest, This, [Previous-This]);
now_calc_increment([], _, Differences) ->
{comment, "Median increment: " ++ integer_to_list(median(Differences))}.
fast_now_unique(0, _) -> ok;
fast_now_unique(N, Then) ->
case now() of
Then ->
?line ?t:fail("now/0 returned the same value twice");
Now ->
fast_now_unique(N-1, Now)
end.
median(Unsorted_List) ->
?line Length = length(Unsorted_List),
?line List = lists:sort(Unsorted_List),
?line case Length rem 2 of
0 -> % Even length.
[A, B] = lists:nthtail((Length div 2)-1, List),
(A+B)/2;
1 -> % Odd list length.
lists:nth((Length div 2)+1, List)
end.
microsecs({Mega_Secs, Secs, Microsecs}) ->
(Mega_Secs*1000000+Secs)*1000000+Microsecs.
%% Test that the time differences returned by two calls to
%% now/0 one second apart is comparable to the difference of two
%% calls to erlang:localtime().
now_update(Config) when is_list(Config) ->
case ?t:is_debug() of
false -> ?line now_update1(10);
true -> {skip,"Unreliable in DEBUG build"}
end.
now_update1(N) when N > 0 ->
?line T1_linear = linear_time(erlang:localtime()),
?line T1_now = microsecs(now()),
?line receive after 1008 -> ok end,
?line T2_linear = linear_time(erlang:localtime()),
?line T2_now = microsecs(now()),
?line Linear_Diff = (T2_linear-T1_linear)*1000000,
?line Now_Diff = T2_now-T1_now,
test_server:format("Localtime diff = ~p; now() diff = ~p",
[Linear_Diff, Now_Diff]),
?line case abs(Linear_Diff - Now_Diff) of
Abs_Delta when Abs_Delta =< 40000 -> ok;
_ -> now_update1(N-1)
end;
now_update1(0) ->
?line test_server:fail().
%% Returns the test data: a list of {Utc, Local} tuples.
test_data() ->
{TZ,DSTTZ} =
case os:type() of
{unix,_} ->
case os:cmd("date '+%Z'") of
"SAST"++_ ->
{2,2};
_ ->
{?timezone,?dst_timezone}
end;
_ ->
{?timezone,?dst_timezone}
end,
?line test_data(nondst_dates(), TZ) ++
test_data(dst_dates(), DSTTZ) ++
crossover_test_data(crossover_dates(), TZ).
%% test_data1() ->
%% ?line test_data(nondst_dates(), ?timezone) ++
%% test_data(dst_dates(), ?dst_timezone) ++
%% crossover_test_data(crossover_dates(), ?timezone).
crossover_test_data([{Year, Month, Day}|Rest], TimeZone) when TimeZone > 0 ->
Hour = 23,
Min = 35,
Sec = 55,
?line Utc = {{Year, Month, Day}, {Hour, Min, Sec}},
?line Local = {{Year, Month, Day+1}, {Hour+TimeZone-24, Min, Sec}},
?line [{Utc, Local}|crossover_test_data(Rest, TimeZone)];
crossover_test_data([{Year, Month, Day}|Rest], TimeZone) when TimeZone < 0 ->
Hour = 0,
Min = 23,
Sec = 12,
?line Utc = {{Year, Month, Day}, {Hour, Min, Sec}},
?line Local = {{Year, Month, Day-1}, {Hour+TimeZone+24, Min, Sec}},
?line [{Utc, Local}|crossover_test_data(Rest, TimeZone)];
crossover_test_data([], _) ->
[].
test_data([Date|Rest], TimeZone) ->
Hour = 12,
Min = 45,
Sec = 7,
?line Utc = {Date, {Hour, Min, Sec}},
?line Local = {Date, {Hour+TimeZone, Min, Sec}},
?line [{Utc, Local}|test_data(Rest, TimeZone)];
test_data([], _) ->
[].
nondst_dates() ->
[{1996, 01, 30},
{1997, 01, 30},
{1998, 01, 30},
{1999, 01, 30},
{1996, 02, 29},
{1997, 02, 28},
{1998, 02, 28},
{1999, 02, 28},
{1996, 03, 2},
{1997, 03, 2},
{1998, 03, 2},
{1999, 03, 2}].
dst_dates() ->
[{1996, 06, 1},
{1997, 06, 2},
{1998, 06, 3},
{1999, 06, 4}].
%% The following dates should not be near the end or beginning of
%% a month, because they will be used to test when the dates are
%% different in UTC and local time.
crossover_dates() ->
[{1996, 01, 25},
{1997, 01, 25},
{1998, 01, 25},
{1999, 01, 25},
{1996, 02, 27},
{1997, 02, 27},
{1998, 02, 27},
{1999, 02, 27}].
bad_dates() ->
[{{1900, 7, 1}, {12, 0, 0}}, % Year
{{1996, 0, 20}, {12, 0, 0}}, % Month
{{1996, 13, 20}, {12, 0, 0}},
{{1996, 1, 0}, {12, 0, 0}}, % Date
{{1996, 1, 32}, {12, 0, 0}},
{{1996, 2, 30}, {12, 0, 0}},
{{1997, 2, 29}, {12, 0, 0}},
{{1998, 2, 29}, {12, 0, 0}},
{{1999, 2, 29}, {12, 0, 0}},
{{1996, 4, 31}, {12, 0, 0}},
{{1996, 4, 30}, {-1, 0, 0}}, % Hour
{{1996, 4, 30}, {25, 0, 0}},
{{1996, 4, 30}, {12,-1, 0}}, % Minute
{{1996, 4, 30}, {12, 60, 0}},
{{1996, 4, 30}, {12, 0, -1}}, % Sec
{{1996, 4, 30}, {12, 0, 60}}].
