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-rw-r--r--lib/stdlib/src/calendar.erl103
1 files changed, 71 insertions, 32 deletions
diff --git a/lib/stdlib/src/calendar.erl b/lib/stdlib/src/calendar.erl
index 9a600c1972..3a8fe2211b 100644
--- a/lib/stdlib/src/calendar.erl
+++ b/lib/stdlib/src/calendar.erl
@@ -1,7 +1,7 @@
%%
%% %CopyrightBegin%
%%
-%% Copyright Ericsson AB 1996-2018. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2019. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
@@ -357,13 +357,17 @@ rfc3339_to_system_time(DateTimeString) ->
rfc3339_to_system_time(DateTimeString, Options) ->
Unit = proplists:get_value(unit, Options, second),
%% _T is the character separating the date and the time:
- {DateStr, [_T|TimeStr]} = lists:split(10, DateTimeString),
- {TimeStr2, TimeStr3} = lists:split(8, TimeStr),
- {ok, [Hour, Min, Sec], []} = io_lib:fread("~d:~d:~d", TimeStr2),
- {ok, [Year, Month, Day], []} = io_lib:fread("~d-~d-~d", DateStr),
+ [Y1, Y2, Y3, Y4, $-, Mon1, Mon2, $-, D1, D2, _T,
+ H1, H2, $:, Min1, Min2, $:, S1, S2 | TimeStr] = DateTimeString,
+ Hour = list_to_integer([H1, H2]),
+ Min = list_to_integer([Min1, Min2]),
+ Sec = list_to_integer([S1, S2]),
+ Year = list_to_integer([Y1, Y2, Y3, Y4]),
+ Month = list_to_integer([Mon1, Mon2]),
+ Day = list_to_integer([D1, D2]),
DateTime = {{Year, Month, Day}, {Hour, Min, Sec}},
IsFractionChar = fun(C) -> C >= $0 andalso C =< $9 orelse C =:= $. end,
- {FractionStr, UtcOffset} = lists:splitwith(IsFractionChar, TimeStr3),
+ {FractionStr, UtcOffset} = lists:splitwith(IsFractionChar, TimeStr),
Time = datetime_to_system_time(DateTime),
Secs = Time - offset_adjustment(Time, second, UtcOffset),
check(DateTimeString, Options, Secs),
@@ -451,8 +455,9 @@ system_time_to_rfc3339(Time, Options) ->
DateTime = system_time_to_datetime(Secs),
{{Year, Month, Day}, {Hour, Min, Sec}} = DateTime,
FractionStr = fraction_str(Factor, AdjustedTime),
- flat_fwrite("~4.10.0B-~2.10.0B-~2.10.0B~c~2.10.0B:~2.10.0B:~2.10.0B~s~s",
- [Year, Month, Day, T, Hour, Min, Sec, FractionStr, Offset]).
+ L = [pad4(Year), "-", pad2(Month), "-", pad2(Day), [T],
+ pad2(Hour), ":", pad2(Min), ":", pad2(Sec), FractionStr, Offset],
+ lists:append(L).
%% time_difference(T1, T2) = Tdiff
%%
@@ -529,24 +534,41 @@ valid_date({Y, M, D}) ->
%% day_to_year(DayOfEpoch) = {Year, DayOfYear}
%%
-%% The idea here is to first guess a year, and then adjust. Although
-%% the implementation is recursive, at most 1 or 2 recursive steps
+%% The idea here is to first set the upper and lower bounds for a year,
+%% and then adjust a range by interpolation search. Although complexity
+%% of the algorithm is log(log(n)), at most 1 or 2 recursive steps
%% are taken.
-%% If DayOfEpoch is very large, we need far more than 1 or 2 iterations,
-%% since we just subtract a yearful of days at a time until we're there.
%%
-spec day_to_year(non_neg_integer()) -> {year(), day_of_year()}.
day_to_year(DayOfEpoch) when DayOfEpoch >= 0 ->
- Y0 = DayOfEpoch div ?DAYS_PER_YEAR,
- {Y1, D1} = dty(Y0, DayOfEpoch, dy(Y0)),
+ YMax = DayOfEpoch div ?DAYS_PER_YEAR,
+ YMin = DayOfEpoch div ?DAYS_PER_LEAP_YEAR,
+ {Y1, D1} = dty(YMin, YMax, DayOfEpoch, dy(YMin), dy(YMax)),
{Y1, DayOfEpoch - D1}.
--spec dty(year(), non_neg_integer(), non_neg_integer()) ->
+-spec dty(year(), year(), non_neg_integer(), non_neg_integer(),
+ non_neg_integer()) ->
{year(), non_neg_integer()}.
-dty(Y, D1, D2) when D1 < D2 ->
- dty(Y-1, D1, dy(Y-1));
-dty(Y, _D1, D2) ->
- {Y, D2}.
+dty(Min, Max, _D1, DMin, _DMax) when Min == Max ->
+ {Min, DMin};
+dty(Min, Max, D1, DMin, DMax) ->
+ Diff = Max - Min,
+ Mid = Min + (Diff * (D1 - DMin)) div (DMax - DMin),
+ MidLength =
+ case is_leap_year(Mid) of
+ true -> ?DAYS_PER_LEAP_YEAR;
+ false -> ?DAYS_PER_YEAR
+ end,
+ case dy(Mid) of
+ D2 when D1 < D2 ->
+ NewMax = Mid - 1,
+ dty(Min, NewMax, D1, DMin, dy(NewMax));
+ D2 when D1 - D2 >= MidLength ->
+ NewMin = Mid + 1,
+ dty(NewMin, Max, D1, dy(NewMin), DMax);
+ D2 ->
+ {Mid, D2}
+ end.
%%
%% The Gregorian days of the iso week 01 day 1 for a given year.
@@ -663,7 +685,7 @@ offset(OffsetOption, Secs0) when OffsetOption =:= "";
Secs = abs(Secs0),
Hour = Secs div 3600,
Min = (Secs rem 3600) div 60,
- io_lib:fwrite("~c~2.10.0B:~2.10.0B", [Sign, Hour, Min]);
+ [Sign | lists:append([pad2(Hour), ":", pad2(Min)])];
offset(OffsetOption, _Secs) ->
OffsetOption.
@@ -678,8 +700,10 @@ offset_string_adjustment(_Time, _Unit, "Z") ->
0;
offset_string_adjustment(_Time, _Unit, "z") ->
0;
-offset_string_adjustment(_Time, _Unit, [Sign|Tz]) ->
- {ok, [Hour, Min], []} = io_lib:fread("~d:~d", Tz),
+offset_string_adjustment(_Time, _Unit, Tz) ->
+ [Sign, H1, H2, $:, M1, M2] = Tz,
+ Hour = list_to_integer([H1, H2]),
+ Min = list_to_integer([M1, M2]),
Adjustment = 3600 * Hour + 60 * Min,
case Sign of
$- -> -Adjustment;
@@ -687,20 +711,19 @@ offset_string_adjustment(_Time, _Unit, [Sign|Tz]) ->
end.
local_offset(SystemTime, Unit) ->
- LocalTime = system_time_to_local_time(SystemTime, Unit),
+ %% Not optimized for special cases.
UniversalTime = system_time_to_universal_time(SystemTime, Unit),
+ LocalTime = erlang:universaltime_to_localtime(UniversalTime),
LocalSecs = datetime_to_gregorian_seconds(LocalTime),
UniversalSecs = datetime_to_gregorian_seconds(UniversalTime),
LocalSecs - UniversalSecs.
+fraction_str(1, _Time) ->
+ "";
fraction_str(Factor, Time) ->
- case Time rem Factor of
- 0 ->
- "";
- Fraction ->
- FS = io_lib:fwrite(".~*..0B", [log10(Factor), abs(Fraction)]),
- string:trim(FS, trailing, "0")
- end.
+ Fraction = Time rem Factor,
+ S = integer_to_list(abs(Fraction)),
+ [$. | pad(log10(Factor) - length(S), S)].
fraction(second, _) ->
0;
@@ -721,5 +744,21 @@ log10(1000) -> 3;
log10(1000000) -> 6;
log10(1000000000) -> 9.
-flat_fwrite(F, S) ->
- lists:flatten(io_lib:fwrite(F, S)).
+pad(0, S) ->
+ S;
+pad(I, S) ->
+ [$0 | pad(I - 1, S)].
+
+pad2(N) when N < 10 ->
+ [$0 | integer_to_list(N)];
+pad2(N) ->
+ integer_to_list(N).
+
+pad4(N) when N < 10 ->
+ [$0, $0, $0 | integer_to_list(N)];
+pad4(N) when N < 100 ->
+ [$0, $0 | integer_to_list(N)];
+pad4(N) when N < 1000 ->
+ [$0 | integer_to_list(N)];
+pad4(N) ->
+ integer_to_list(N).
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-01 15:26:47 +0000