forks/ezic
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

datetime manipulation is now much clearer. tests were added, and expectations stated explicitly in many places. rules got lots of attention.

Browse Source
This commit is contained in:
aj
2010-11-10 01:52:13 -08:00
parent 216a8d9ff8
commit d84a0c1822
11 changed files with 245 additions and 116 deletions
Download Patch File Download Diff File Expand all files Collapse all files

102
src/ezic_date.erl
View File

@@ -7,7 +7,7 @@
-export([
% rule-specific
for_rule/2
, for_rule_zone/3
, for_rule_utc/4
% converters
@@ -17,7 +17,12 @@
% date math
, add_seconds/2
, add_offset/2
, all_times/3
% comparisons
, compare/2
, equal/2
]).
@@ -27,26 +32,20 @@
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% returns {Y,M,D} for a rule and Year
for_rule(#rule{in=M, on={last, D}}, Y) ->
last_day_of(D, Y,M);
for_rule(#rule{in=M, on=#tzon{day=Day, filter=Filter}}, Y) ->
first_day_limited(Day, Filter, Y,M).
% returns RELATIVE {Y,M,D} for a rule and Year
for_rule(#rule{in=M, on=D, at=At}, Y) when is_integer(D) ->
{{Y,M,D}, At};
for_rule(#rule{in=M, on={last, D}, at=At}, Y) ->
{last_day_of(D, Y,M), At};
for_rule(#rule{in=M, on=#tzon{day=Day, filter=Filter}, at=At}, Y) ->
{first_day_limited(Day, Filter, Y,M), At}.
% for_rule(#rule{}, Zone, Year) -> {WallTime, STDTime, UTCTime}
% returns the date set for a given rule and year
% same for all timezones.
for_rule_zone(#rule{in=M, on={last, D}, at=_Time, save=_DSTOffset}, _Zone=#zone{gmtoff=_Offset}, Y) ->
_LDO= last_day_of(D, Y,M),
not_done;
for_rule_zone(#rule{in=M, on=#tzon{day=Day, filter=Filter}}, _Zone, Y) ->
first_day_limited(Day, Filter, Y,M),
not_done.
% returns UTC datetime for rule, offset, and year
for_rule_utc(Rule, Offset, DSTOffset, Year) ->
DT= for_rule(Rule, Year),
{_,_,UTCDatetime} = all_times(DT, Offset, DSTOffset),
UTCDatetime.
@@ -89,47 +88,83 @@ add_seconds(Datetime, Seconds) ->
add_offset(Datetime, Offset) ->
Sec= calendar:time_to_seconds(Offset),
add_seconds(Datetime, Sec).
% returns {WallTime, StdTime, UtcTime}
% where each is a datetime tuple: {{Y,M,D}{HH,MM,SS}}
% universal time given
all_times(#tztime{time=UTCTime, flag=Flag}, Offset, DSTOffset)
all_times({Date, #tztime{time=UTCTime, flag=Flag}}, Offset, DSTOffset)
when Flag=:=u; Flag=:=g; Flag=:=z ->
UTCDatetime= {Date, UTCTime},
OSec= calendar:time_to_seconds(Offset),
DSTSec= calendar:time_to_seconds(DSTOffset),
STDTime= add_seconds(UTCTime, OSec),
STDTime= add_seconds(UTCDatetime, OSec),
WallTime= add_seconds(STDTime, DSTSec),
{WallTime, STDTime, UTCTime};
{WallTime, STDTime, UTCDatetime};
% standard time given
all_times(#tztime{time=STDTime, flag=s}, Offset, DSTOffset) ->
all_times({Date, #tztime{time=STDTime, flag=s}}, Offset, DSTOffset) ->
STDDatetime= {Date, STDTime},
OSec= calendar:time_to_seconds(Offset),
DSTSec= calendar:time_to_seconds(DSTOffset),
UTCTime= add_seconds(STDTime, -1*OSec),
WallTime= add_seconds(STDTime, DSTSec),
UTCTime= add_seconds(STDDatetime, -1*OSec),
WallTime= add_seconds(STDDatetime, DSTSec),
{WallTime, STDTime, UTCTime};
{WallTime, STDDatetime, UTCTime};
% wall time given
all_times(#tztime{time=WallTime, flag=Flag}, Offset, DSTOffset)
when Flag=:=w, Flag=:=undefined ->
all_times({Date, #tztime{time=WallTime, flag=Flag}}, Offset, DSTOffset)
when Flag=:=w; Flag=:=undefined ->
WallDatetime= {Date, WallTime},
OSec= calendar:time_to_seconds(Offset),
DSTSec= calendar:time_to_seconds(DSTOffset),
STDTime= add_seconds(WallTime, -1*DSTSec),
STDTime= add_seconds(WallDatetime, -1*DSTSec),
UTCTime= add_seconds(STDTime, -1*OSec),
{WallTime, STDTime, UTCTime}.
{WallDatetime, STDTime, UTCTime}.
% returns true if DT1 =< DT2. False otherwise. can be used with lists:sort/2
% both times are assumed to be in the same zone/DST context
compare(DT1={{Y1,M1,D1},{HH1,MM1,SS1}}, DT2={{Y2,M2,D2},{HH2,MM2,SS2}})
when is_integer(Y1), is_integer(Y2)
, is_integer(M1), is_integer(M2)
, is_integer(D1), is_integer(D2)
, is_integer(HH1), is_integer(HH2)
, is_integer(MM1), is_integer(MM2)
, is_integer(SS1), is_integer(SS2)
->
DT1 =< DT2.
% returns true if DT1 =:= DT2. False otherwise
% both times are assumed to be in the same zone/DST context
equal(DT1={{Y1,M1,D1},{HH1,MM1,SS1}}, DT2={{Y2,M2,D2},{HH2,MM2,SS2}})
when is_integer(Y1), is_integer(Y2)
, is_integer(M1), is_integer(M2)
, is_integer(D1), is_integer(D2)
, is_integer(HH1), is_integer(HH2)
, is_integer(MM1), is_integer(MM2)
, is_integer(SS1), is_integer(SS2)
->
DT1 =:= DT2.
@@ -211,10 +246,3 @@ add_days_in_month(Days, Date={Y,M,D}) ->
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
normalize(_Datetime) ->
not_done.
compare_normal(_DT1, _DT2) ->
not_done.

51
src/ezic_flatten.erl
View File

@@ -88,55 +88,28 @@ flatten_zone_set(Zones) ->
% assumes a new zone every time it is called
flatten_zone_set(_, [], Flats) ->
Flats;
flatten_zone_set(FromTimeStub, [Z1=#zone{rule=RuleName, until=UntilTime, gmtoff=Offset} | _RestZones] = _Zones, _Flats) ->
flatten_zone_set(FromTimeStub=#flatzone{utc_from=UTCFrom, dstoffset=DSTOffset}, [Z1=#zone{rule=RuleName, until=UntilTime, gmtoff=Offset} | _RestZones], _Flats) ->
%% we have a flatzone with start times, we populate the base offset
FromTime= FromTimeStub#flatzone{offset=Offset},
%% note that dst offset default to {0,0,0} in #flatzone{}
%% we gather all rules that _may_ apply (same year)
Rules= ezic_db:rules(RuleName),
RelevantRules= ezic_rule:filter(FromTime, UntilTime, Rules),
SortedRules= lists:sort(fun ezic_rule:sort_ascending/2, RelevantRules),
%% Then we plot points, bouncing from rule to rule, ending when the zone ends
{ok, _NextFromTimeStub, _NewFlats}= flatten_zone(FromTime, Z1, SortedRules),
RuleDates= lists:foldl(
fun(R, Acc)->
case ezic_rule:project_next(R, Offset, DSTOffset, UTCFrom) of
none -> Acc;
D -> [{D,R} | Acc]
end
end
,[], Rules),
AllDates= [{ezic_zone:project_end(Z1, DSTOffset), Z1} | RuleDates],
not_done.
% flattens a single zone into multiple flatzones.
% FromTime has its *_from fields and offset field populated. (it should anyway)
% @todo invalid input checking
% Rules are sorted
flatten_zone(BaseFlat, Zone, Rules) ->
flatten_zone(BaseFlat, Zone, Rules, []).
flatten_zone(BaseFlat, Zone=#zone{until=Until, gmtoff=Offset}, Rules, Flats) ->
case ezic_rule:next_event(BaseFlat, Until, Offset, Rules) of
% is this enough information to compare all times corectly?
{end_until, EndTimes} ->
NewFlats= [end_flat(BaseFlat, EndTimes) | Flats],
NewFrom= make_next_flat(EndTimes),
{ok, NewFrom, NewFlats}; % base case
{end_rule, EndTimes, NextOffset} ->
NewFlats= [end_flat(BaseFlat, EndTimes) | Flats],
NewFrom= make_next_flat(EndTimes, NextOffset),
flatten_zone(NewFrom, Zone, Rules, NewFlats) % tail recursion
end.

2
src/ezic_parse.erl
View File

@@ -145,7 +145,7 @@ time_flag_rev([F|RTime]) when F =:= $g; F =:= $z ->
time_flag_rev(X=[F|_]) when F-48 < 0; F-48 > 9 ->
erlang:error(badtime, lists:reverse(X));
time_flag_rev(RTime) ->
{undefined, RTime}.
{w, RTime}.

5
src/ezic_record.erl
View File

@@ -3,11 +3,6 @@
-include_lib("eunit/include/eunit.hrl").
-ifdef(TEST).
-compile([export_all]).
-endif.
-export([
link/1
, leap/1

91
src/ezic_rule.erl
View File

@@ -3,8 +3,7 @@
-export([parse/1]).
-export([next_event/4]).
-export([project_next/4]).
parse([Name,FromS,ToS,_Type,InS,OnS,AtS,SaveS,Letters]) ->
@@ -25,37 +24,38 @@ parse([Name,FromS,ToS,_Type,InS,OnS,AtS,SaveS,Letters]) ->
% determines the next zone or dst change event
% returns the latest possible times the previous period is in effect (`Until -1sec` in most cases)
% Rules are sorted
next_event(_BaseFlat, ZoneEnd, Offset, []) ->
{end_until, make_times(ZoneEnd, Offset)};
% BaseFlat has offset defined
% @todo ensure offset defined on BaseFlat
% Rules are sorted in ascending order (oldest first)
next_event(_BaseFlat=#flatzone{utc_from=#tztime{time={{_Year,_,_},_}}},
_ZoneEnd, _ZoneOffset, [_Rule|_RestRules]) ->
not_done.
% returns the projected date of the next "rule event" in UTC time,
% after the given UTCDatetime, with the given the zone Offset and current DST offset.
project_next(Rule=#rule{from=RFrom, to=RTo}, Offset, DSTOff, UTCAfter={{AY,_,_},_}) ->
AllYears= years(Rule),
GoodYears= years_after(AY, AllYears),
project_next2(Rule, Offset, UTCAfter, DSTOff, GoodYears).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% PRIVATE
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% create endtimes for a #flatzone, with no dst offset
make_times(Until, Offset) ->
make_times(Until, Offset, 0).
make_times(Until, Offset, DSTOffset) ->
ezic_date:all_times(Until, Offset, DSTOffset).
% returns the sorted list of years a rule existed for.
years(Rule=#rule{from=From, to=only}) ->
[From];
years(Rule=#rule{from=From, to=To}) ->
try lists:seq(From, To)
catch error:function_clause ->
erlang:error(bad_year_range)
end.
% returns the years from the list that are greater than OR equal to Y
years_after(Y, []) ->
[];
years_after(Y, Years) ->
{GOOD, _}= lists:partition(
fun(X) when Y =< X -> true;
(_) -> false
end, Years),
GOOD.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% INTERNAL
@@ -63,4 +63,45 @@ make_times(Until, Offset, DSTOffset) ->
project_next2(_,_,_,_,[]) ->
none;
project_next2(Rule, Offset, UTCAfter, DSTOffset, [Year|RestYears]) ->
RuleDate= ezic_date:for_rule_utc(Rule, Offset, DSTOffset, Year),
case ezic_date:compare(UTCAfter, RuleDate) andalso (not ezic_date:equal(UTCAfter, RuleDate)) of
true -> RuleDate;
_ -> project_next2(Rule, Offset, UTCAfter, DSTOffset, RestYears)
end.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Tests of Private Methods
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-ifdef(TEST).
-include_lib("eunit/include/eunit.hrl").
years_test_() ->
[
?_assertEqual([1952], years(#rule{from=1952,to=only}))
, ?_assertEqual([1952,1953], years(#rule{from=1952,to=1953}))
, ?_assertEqual([1952,1953,1954,1955], years(#rule{from=1952,to=1955}))
, ?_assertError(bad_year_range, years(#rule{from=1955,to=1952}))
].
% @todo type checking. lack of types worries me sometimes :(
years_after_test_() ->
[
?_assertEqual([2010], years_after(2010, [2010]))
, ?_assertEqual([2010,2011], years_after(2010, [2010,2011]))
, ?_assertEqual([2011], years_after(2011, [2010,2011]))
, ?_assertEqual([], years_after(2012, [2010,2011]))
, ?_assertEqual([], years_after(2012, []))
].
-endif.

7
src/ezic_zone.erl
View File

@@ -10,6 +10,8 @@
, sort_ascending/2
, sort_descending/2
, offset_sec/1
, project_end/2
]).
@@ -94,6 +96,11 @@ offset_sec(Zone) ->
% returns the UTC datetime projected for zone end (given current DST Offset)
project_end(#zone{until=Until, gmtoff=Offset}, DSTOffset) ->
{_,_,UTCDatetime}= ezic_date:all_times(Until, Offset, DSTOffset),
UTCDatetime.