Date.cpp 15 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404
  1. /*
  2. * Copyright (c) 2020-2022, Linus Groh <linusg@serenityos.org>
  3. * Copyright (c) 2022, Tim Flynn <trflynn89@serenityos.org>
  4. *
  5. * SPDX-License-Identifier: BSD-2-Clause
  6. */
  7. #include <AK/NumericLimits.h>
  8. #include <AK/StringBuilder.h>
  9. #include <AK/Time.h>
  10. #include <LibCore/DateTime.h>
  11. #include <LibJS/Runtime/AbstractOperations.h>
  12. #include <LibJS/Runtime/Date.h>
  13. #include <LibJS/Runtime/GlobalObject.h>
  14. #include <LibTimeZone/TimeZone.h>
  15. #include <time.h>
  16. namespace JS {
  17. Date* Date::create(GlobalObject& global_object, double date_value)
  18. {
  19. return global_object.heap().allocate<Date>(global_object, date_value, *global_object.date_prototype());
  20. }
  21. Date::Date(double date_value, Object& prototype)
  22. : Object(prototype)
  23. , m_date_value(date_value)
  24. {
  25. }
  26. String Date::iso_date_string() const
  27. {
  28. int year = year_from_time(m_date_value);
  29. StringBuilder builder;
  30. if (year < 0)
  31. builder.appendff("-{:06}", -year);
  32. else if (year > 9999)
  33. builder.appendff("+{:06}", year);
  34. else
  35. builder.appendff("{:04}", year);
  36. builder.append('-');
  37. builder.appendff("{:02}", month_from_time(m_date_value) + 1);
  38. builder.append('-');
  39. builder.appendff("{:02}", date_from_time(m_date_value));
  40. builder.append('T');
  41. builder.appendff("{:02}", hour_from_time(m_date_value));
  42. builder.append(':');
  43. builder.appendff("{:02}", min_from_time(m_date_value));
  44. builder.append(':');
  45. builder.appendff("{:02}", sec_from_time(m_date_value));
  46. builder.append('.');
  47. builder.appendff("{:03}", ms_from_time(m_date_value));
  48. builder.append('Z');
  49. return builder.build();
  50. }
  51. // DayWithinYear(t), https://tc39.es/ecma262/#eqn-DayWithinYear
  52. u16 day_within_year(double t)
  53. {
  54. if (!Value(t).is_finite_number())
  55. return 0;
  56. // Day(t) - DayFromYear(YearFromTime(t))
  57. return static_cast<u16>(day(t) - day_from_year(year_from_time(t)));
  58. }
  59. // DateFromTime(t), https://tc39.es/ecma262/#sec-date-number
  60. u8 date_from_time(double t)
  61. {
  62. switch (month_from_time(t)) {
  63. // DayWithinYear(t) + 1𝔽 if MonthFromTime(t) = +0𝔽
  64. case 0:
  65. return day_within_year(t) + 1;
  66. // DayWithinYear(t) - 30𝔽 if MonthFromTime(t) = 1𝔽
  67. case 1:
  68. return day_within_year(t) - 30;
  69. // DayWithinYear(t) - 58𝔽 - InLeapYear(t) if MonthFromTime(t) = 2𝔽
  70. case 2:
  71. return day_within_year(t) - 58 - in_leap_year(t);
  72. // DayWithinYear(t) - 89𝔽 - InLeapYear(t) if MonthFromTime(t) = 3𝔽
  73. case 3:
  74. return day_within_year(t) - 89 - in_leap_year(t);
  75. // DayWithinYear(t) - 119𝔽 - InLeapYear(t) if MonthFromTime(t) = 4𝔽
  76. case 4:
  77. return day_within_year(t) - 119 - in_leap_year(t);
  78. // DayWithinYear(t) - 150𝔽 - InLeapYear(t) if MonthFromTime(t) = 5𝔽
  79. case 5:
  80. return day_within_year(t) - 150 - in_leap_year(t);
  81. // DayWithinYear(t) - 180𝔽 - InLeapYear(t) if MonthFromTime(t) = 6𝔽
  82. case 6:
  83. return day_within_year(t) - 180 - in_leap_year(t);
  84. // DayWithinYear(t) - 211𝔽 - InLeapYear(t) if MonthFromTime(t) = 7𝔽
  85. case 7:
  86. return day_within_year(t) - 211 - in_leap_year(t);
  87. // DayWithinYear(t) - 242𝔽 - InLeapYear(t) if MonthFromTime(t) = 8𝔽
  88. case 8:
  89. return day_within_year(t) - 242 - in_leap_year(t);
  90. // DayWithinYear(t) - 272𝔽 - InLeapYear(t) if MonthFromTime(t) = 9𝔽
  91. case 9:
  92. return day_within_year(t) - 272 - in_leap_year(t);
  93. // DayWithinYear(t) - 303𝔽 - InLeapYear(t) if MonthFromTime(t) = 10𝔽
  94. case 10:
  95. return day_within_year(t) - 303 - in_leap_year(t);
  96. // DayWithinYear(t) - 333𝔽 - InLeapYear(t) if MonthFromTime(t) = 11𝔽
  97. case 11:
  98. return day_within_year(t) - 333 - in_leap_year(t);
  99. default:
  100. VERIFY_NOT_REACHED();
  101. }
  102. }
  103. // DaysInYear(y), https://tc39.es/ecma262/#eqn-DaysInYear
  104. u16 days_in_year(i32 y)
  105. {
  106. // 365𝔽 if (ℝ(y) modulo 4) ≠ 0
  107. if (y % 4 != 0)
  108. return 365;
  109. // 366𝔽 if (ℝ(y) modulo 4) = 0 and (ℝ(y) modulo 100) ≠ 0
  110. if (y % 4 == 0 && y % 100 != 0)
  111. return 366;
  112. // 365𝔽 if (ℝ(y) modulo 100) = 0 and (ℝ(y) modulo 400) ≠ 0
  113. if (y % 100 == 0 && y % 400 != 0)
  114. return 365;
  115. // 366𝔽 if (ℝ(y) modulo 400) = 0
  116. if (y % 400 == 0)
  117. return 366;
  118. VERIFY_NOT_REACHED();
  119. }
  120. // DayFromYear(y), https://tc39.es/ecma262/#eqn-DaysFromYear
  121. double day_from_year(i32 y)
  122. {
  123. // 𝔽(365 × (ℝ(y) - 1970) + floor((ℝ(y) - 1969) / 4) - floor((ℝ(y) - 1901) / 100) + floor((ℝ(y) - 1601) / 400))
  124. return 365.0 * (y - 1970) + floor((y - 1969) / 4.0) - floor((y - 1901) / 100.0) + floor((y - 1601) / 400.0);
  125. }
  126. // TimeFromYear(y), https://tc39.es/ecma262/#eqn-TimeFromYear
  127. double time_from_year(i32 y)
  128. {
  129. // msPerDay × DayFromYear(y)
  130. return ms_per_day * day_from_year(y);
  131. }
  132. // YearFromTime(t), https://tc39.es/ecma262/#eqn-YearFromTime
  133. i32 year_from_time(double t)
  134. {
  135. // the largest integral Number y (closest to +∞) such that TimeFromYear(y) ≤ t
  136. if (!Value(t).is_finite_number())
  137. return NumericLimits<i32>::max();
  138. // Approximation using average number of milliseconds per year. We might have to adjust this guess afterwards.
  139. auto year = static_cast<i32>(t / (365.2425 * ms_per_day) + 1970);
  140. auto year_t = time_from_year(year);
  141. if (year_t > t)
  142. year--;
  143. else if (year_t + days_in_year(year) * ms_per_day <= t)
  144. year++;
  145. return year;
  146. }
  147. // InLeapYear(t), https://tc39.es/ecma262/#eqn-InLeapYear
  148. bool in_leap_year(double t)
  149. {
  150. // +0𝔽 if DaysInYear(YearFromTime(t)) = 365𝔽
  151. // 1𝔽 if DaysInYear(YearFromTime(t)) = 366𝔽
  152. return days_in_year(year_from_time(t)) == 366;
  153. }
  154. // MonthFromTime(t), https://tc39.es/ecma262/#eqn-MonthFromTime
  155. u8 month_from_time(double t)
  156. {
  157. auto in_leap_year = JS::in_leap_year(t);
  158. auto day_within_year = JS::day_within_year(t);
  159. // +0𝔽 if +0𝔽 ≤ DayWithinYear(t) < 31𝔽
  160. if (day_within_year < 31)
  161. return 0;
  162. // 1𝔽 if 31𝔽 ≤ DayWithinYear(t) < 59𝔽 + InLeapYear(t)
  163. if (31 <= day_within_year && day_within_year < 59 + in_leap_year)
  164. return 1;
  165. // 2𝔽 if 59𝔽 + InLeapYear(t) ≤ DayWithinYear(t) < 90𝔽 + InLeapYear(t)
  166. if (59 + in_leap_year <= day_within_year && day_within_year < 90 + in_leap_year)
  167. return 2;
  168. // 3𝔽 if 90𝔽 + InLeapYear(t) ≤ DayWithinYear(t) < 120𝔽 + InLeapYear(t)
  169. if (90 + in_leap_year <= day_within_year && day_within_year < 120 + in_leap_year)
  170. return 3;
  171. // 4𝔽 if 120𝔽 + InLeapYear(t) ≤ DayWithinYear(t) < 151𝔽 + InLeapYear(t)
  172. if (120 + in_leap_year <= day_within_year && day_within_year < 151 + in_leap_year)
  173. return 4;
  174. // 5𝔽 if 151𝔽 + InLeapYear(t) ≤ DayWithinYear(t) < 181𝔽 + InLeapYear(t)
  175. if (151 + in_leap_year <= day_within_year && day_within_year < 181 + in_leap_year)
  176. return 5;
  177. // 6𝔽 if 181𝔽 + InLeapYear(t) ≤ DayWithinYear(t) < 212𝔽 + InLeapYear(t)
  178. if (181 + in_leap_year <= day_within_year && day_within_year < 212 + in_leap_year)
  179. return 6;
  180. // 7𝔽 if 212𝔽 + InLeapYear(t) ≤ DayWithinYear(t) < 243𝔽 + InLeapYear(t)
  181. if (212 + in_leap_year <= day_within_year && day_within_year < 243 + in_leap_year)
  182. return 7;
  183. // 8𝔽 if 243𝔽 + InLeapYear(t) ≤ DayWithinYear(t) < 273𝔽 + InLeapYear(t)
  184. if (243 + in_leap_year <= day_within_year && day_within_year < 273 + in_leap_year)
  185. return 8;
  186. // 9𝔽 if 273𝔽 + InLeapYear(t) ≤ DayWithinYear(t) < 304𝔽 + InLeapYear(t)
  187. if (273 + in_leap_year <= day_within_year && day_within_year < 304 + in_leap_year)
  188. return 9;
  189. // 10𝔽 if 304𝔽 + InLeapYear(t) ≤ DayWithinYear(t) < 334𝔽 + InLeapYear(t)
  190. if (304 + in_leap_year <= day_within_year && day_within_year < 334 + in_leap_year)
  191. return 10;
  192. // 11𝔽 if 334𝔽 + InLeapYear(t) ≤ DayWithinYear(t) < 365𝔽 + InLeapYear(t)
  193. if (334 + in_leap_year <= day_within_year && day_within_year < 365 + in_leap_year)
  194. return 11;
  195. VERIFY_NOT_REACHED();
  196. }
  197. // HourFromTime(t), https://tc39.es/ecma262/#eqn-HourFromTime
  198. u8 hour_from_time(double t)
  199. {
  200. if (!Value(t).is_finite_number())
  201. return 0;
  202. // 𝔽(floor(ℝ(t / msPerHour)) modulo HoursPerDay)
  203. return static_cast<u8>(modulo(floor(t / ms_per_hour), hours_per_day));
  204. }
  205. // MinFromTime(t), https://tc39.es/ecma262/#eqn-MinFromTime
  206. u8 min_from_time(double t)
  207. {
  208. if (!Value(t).is_finite_number())
  209. return 0;
  210. // 𝔽(floor(ℝ(t / msPerMinute)) modulo MinutesPerHour)
  211. return static_cast<u8>(modulo(floor(t / ms_per_minute), minutes_per_hour));
  212. }
  213. // SecFromTime(t), https://tc39.es/ecma262/#eqn-SecFromTime
  214. u8 sec_from_time(double t)
  215. {
  216. if (!Value(t).is_finite_number())
  217. return 0;
  218. // 𝔽(floor(ℝ(t / msPerSecond)) modulo SecondsPerMinute)
  219. return static_cast<u8>(modulo(floor(t / ms_per_second), seconds_per_minute));
  220. }
  221. // msFromTime(t), https://tc39.es/ecma262/#eqn-msFromTime
  222. u16 ms_from_time(double t)
  223. {
  224. if (!Value(t).is_finite_number())
  225. return 0;
  226. // 𝔽(ℝ(t) modulo ℝ(msPerSecond))
  227. return static_cast<u16>(modulo(t, ms_per_second));
  228. }
  229. // 21.4.1.6 Week Day, https://tc39.es/ecma262/#sec-week-day
  230. u8 week_day(double t)
  231. {
  232. if (!Value(t).is_finite_number())
  233. return 0;
  234. // 𝔽(ℝ(Day(t) + 4𝔽) modulo 7)
  235. return static_cast<u8>(modulo(day(t) + 4, 7));
  236. }
  237. // 21.4.1.7 LocalTZA ( t, isUTC ), https://tc39.es/ecma262/#sec-local-time-zone-adjustment
  238. double local_tza(double time, [[maybe_unused]] bool is_utc, Optional<StringView> time_zone_override)
  239. {
  240. // The time_zone_override parameter is non-standard, but allows callers to override the system
  241. // time zone with a specific value without setting environment variables.
  242. auto time_zone = time_zone_override.value_or(TimeZone::current_time_zone());
  243. // When isUTC is true, LocalTZA( tUTC, true ) should return the offset of the local time zone from
  244. // UTC measured in milliseconds at time represented by time value tUTC. When the result is added to
  245. // tUTC, it should yield the corresponding Number tlocal.
  246. // When isUTC is false, LocalTZA( tlocal, false ) should return the offset of the local time zone from
  247. // UTC measured in milliseconds at local time represented by Number tlocal. When the result is subtracted
  248. // from tlocal, it should yield the corresponding time value tUTC.
  249. auto time_since_epoch = Value(time).is_finite_number() ? AK::Time::from_milliseconds(time) : AK::Time::max();
  250. auto maybe_offset = TimeZone::get_time_zone_offset(time_zone, time_since_epoch);
  251. return maybe_offset.has_value() ? static_cast<double>(maybe_offset->seconds) * 1000 : 0;
  252. }
  253. // 21.4.1.8 LocalTime ( t ), https://tc39.es/ecma262/#sec-localtime
  254. double local_time(double time)
  255. {
  256. // 1. Return t + LocalTZA(t, true).
  257. return time + local_tza(time, true);
  258. }
  259. // 21.4.1.9 UTC ( t ), https://tc39.es/ecma262/#sec-utc-t
  260. double utc_time(double time)
  261. {
  262. // 1. Return t - LocalTZA(t, false).
  263. return time - local_tza(time, false);
  264. }
  265. // 21.4.1.11 MakeTime ( hour, min, sec, ms ), https://tc39.es/ecma262/#sec-maketime
  266. Value make_time(GlobalObject& global_object, Value hour, Value min, Value sec, Value ms)
  267. {
  268. // 1. If hour is not finite or min is not finite or sec is not finite or ms is not finite, return NaN.
  269. if (!hour.is_finite_number() || !min.is_finite_number() || !sec.is_finite_number() || !ms.is_finite_number())
  270. return js_nan();
  271. // 2. Let h be 𝔽(! ToIntegerOrInfinity(hour)).
  272. auto h = MUST(hour.to_integer_or_infinity(global_object));
  273. // 3. Let m be 𝔽(! ToIntegerOrInfinity(min)).
  274. auto m = MUST(min.to_integer_or_infinity(global_object));
  275. // 4. Let s be 𝔽(! ToIntegerOrInfinity(sec)).
  276. auto s = MUST(sec.to_integer_or_infinity(global_object));
  277. // 5. Let milli be 𝔽(! ToIntegerOrInfinity(ms)).
  278. auto milli = MUST(ms.to_integer_or_infinity(global_object));
  279. // 6. Let t be ((h * msPerHour + m * msPerMinute) + s * msPerSecond) + milli, performing the arithmetic according to IEEE 754-2019 rules (that is, as if using the ECMAScript operators * and +).
  280. // NOTE: C++ arithmetic abides by IEEE 754 rules
  281. auto t = ((h * ms_per_hour + m * ms_per_minute) + s * ms_per_second) + milli;
  282. // 7. Return t.
  283. return Value(t);
  284. }
  285. // Day(t), https://tc39.es/ecma262/#eqn-Day
  286. double day(double time_value)
  287. {
  288. return floor(time_value / ms_per_day);
  289. }
  290. // TimeWithinDay(t), https://tc39.es/ecma262/#eqn-TimeWithinDay
  291. double time_within_day(double time)
  292. {
  293. // 𝔽(ℝ(t) modulo ℝ(msPerDay))
  294. return modulo(time, ms_per_day);
  295. }
  296. // 21.4.1.12 MakeDay ( year, month, date ), https://tc39.es/ecma262/#sec-makeday
  297. Value make_day(GlobalObject& global_object, Value year, Value month, Value date)
  298. {
  299. // 1. If year is not finite or month is not finite or date is not finite, return NaN.
  300. if (!year.is_finite_number() || !month.is_finite_number() || !date.is_finite_number())
  301. return js_nan();
  302. // 2. Let y be 𝔽(! ToIntegerOrInfinity(year)).
  303. auto y = MUST(year.to_integer_or_infinity(global_object));
  304. // 3. Let m be 𝔽(! ToIntegerOrInfinity(month)).
  305. auto m = MUST(month.to_integer_or_infinity(global_object));
  306. // 4. Let dt be 𝔽(! ToIntegerOrInfinity(date)).
  307. auto dt = MUST(date.to_integer_or_infinity(global_object));
  308. // 5. Let ym be y + 𝔽(floor(ℝ(m) / 12)).
  309. auto ym = y + floor(m / 12);
  310. // 6. If ym is not finite, return NaN.
  311. if (!Value(ym).is_finite_number())
  312. return js_nan();
  313. // 7. Let mn be 𝔽(ℝ(m) modulo 12).
  314. auto mn = modulo(m, 12);
  315. // 8. Find a finite time value t such that YearFromTime(t) is ym and MonthFromTime(t) is mn and DateFromTime(t) is 1𝔽; but if this is not possible (because some argument is out of range), return NaN.
  316. if (!AK::is_within_range<int>(ym) || !AK::is_within_range<int>(mn + 1))
  317. return js_nan();
  318. // FIXME: We are avoiding AK::years_to_days_since_epoch here because it is implemented by looping over
  319. // the range [1970, ym), which will spin for any time value with an extremely large year.
  320. auto t = time_from_year(ym) + (day_of_year(static_cast<int>(ym), static_cast<int>(mn) + 1, 1) * ms_per_day);
  321. // 9. Return Day(t) + dt - 1𝔽.
  322. return Value(day(static_cast<double>(t)) + dt - 1);
  323. }
  324. // 21.4.1.13 MakeDate ( day, time ), https://tc39.es/ecma262/#sec-makedate
  325. Value make_date(Value day, Value time)
  326. {
  327. // 1. If day is not finite or time is not finite, return NaN.
  328. if (!day.is_finite_number() || !time.is_finite_number())
  329. return js_nan();
  330. // 2. Let tv be day × msPerDay + time.
  331. auto tv = Value(day.as_double() * ms_per_day + time.as_double());
  332. // 3. If tv is not finite, return NaN.
  333. if (!tv.is_finite_number())
  334. return js_nan();
  335. // 4. Return tv.
  336. return tv;
  337. }
  338. // 21.4.1.14 TimeClip ( time ), https://tc39.es/ecma262/#sec-timeclip
  339. Value time_clip(GlobalObject& global_object, Value time)
  340. {
  341. // 1. If time is not finite, return NaN.
  342. if (!time.is_finite_number())
  343. return js_nan();
  344. // 2. If abs(ℝ(time)) > 8.64 × 10^15, return NaN.
  345. if (fabs(time.as_double()) > 8.64E15)
  346. return js_nan();
  347. // 3. Return 𝔽(! ToIntegerOrInfinity(time)).
  348. return Value(MUST(time.to_integer_or_infinity(global_object)));
  349. }
  350. }