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Diffstat (limited to 'src/timefns.c')
| -rw-r--r-- | src/timefns.c | 1752 |
1 files changed, 1752 insertions, 0 deletions
diff --git a/src/timefns.c b/src/timefns.c new file mode 100644 index 00000000000..58dda1c7061 --- /dev/null +++ b/src/timefns.c @@ -0,0 +1,1752 @@ +/* Timestamp functions for Emacs + +Copyright (C) 1985-1987, 1989, 1993-2018 Free Software Foundation, Inc. + +This file is part of GNU Emacs. + +GNU Emacs is free software: you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation, either version 3 of the License, or (at +your option) any later version. + +GNU Emacs is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>. */ + +#include <config.h> + +#include "systime.h" + +#include "blockinput.h" +#include "bignum.h" +#include "coding.h" +#include "lisp.h" + +#include <strftime.h> + +#include <errno.h> +#include <limits.h> +#include <math.h> +#include <stdio.h> +#include <stdlib.h> + +#ifdef HAVE_TIMEZONE_T +# include <sys/param.h> +# if defined __NetBSD_Version__ && __NetBSD_Version__ < 700000000 +# define HAVE_TZALLOC_BUG true +# endif +#endif +#ifndef HAVE_TZALLOC_BUG +# define HAVE_TZALLOC_BUG false +#endif + +#define TM_YEAR_BASE 1900 + +#ifndef HAVE_TM_GMTOFF +# define HAVE_TM_GMTOFF false +#endif + +#ifndef TIME_T_MIN +# define TIME_T_MIN TYPE_MINIMUM (time_t) +#endif +#ifndef TIME_T_MAX +# define TIME_T_MAX TYPE_MAXIMUM (time_t) +#endif + +/* Compile with -DFASTER_TIMEFNS=0 to disable common optimizations and + allow easier testing of some slow-path code. */ +#ifndef FASTER_TIMEFNS +# define FASTER_TIMEFNS 1 +#endif + +/* Whether to warn about Lisp timestamps (TICKS . HZ) that may be + instances of obsolete-format timestamps (HI . LO) where HI is + the high-order bits and LO the low-order 16 bits. Currently this + is true, but it should change to false in a future version of + Emacs. Compile with -DWARN_OBSOLETE_TIMESTAMPS=0 to see what the + future will be like. */ +#ifndef WARN_OBSOLETE_TIMESTAMPS +enum { WARN_OBSOLETE_TIMESTAMPS = true }; +#endif + +/* Although current-time etc. generate list-format timestamps + (HI LO US PS), the plan is to change these functions to generate + frequency-based timestamps (TICKS . HZ) in a future release. + To try this now, compile with -DCURRENT_TIME_LIST=0. */ +#ifndef CURRENT_TIME_LIST +enum { CURRENT_TIME_LIST = true }; +#endif + +#if FIXNUM_OVERFLOW_P (1000000000) +static Lisp_Object timespec_hz; +#else +# define timespec_hz make_fixnum (TIMESPEC_HZ) +#endif + +#define TRILLION 1000000000000 +#if FIXNUM_OVERFLOW_P (TRILLION) +static Lisp_Object trillion; +# define ztrillion (XBIGNUM (trillion)->value) +#else +# define trillion make_fixnum (TRILLION) +# if ULONG_MAX < TRILLION || !FASTER_TIMEFNS +mpz_t ztrillion; +# endif +#endif + +/* Return a struct timeval that is roughly equivalent to T. + Use the least timeval not less than T. + Return an extremal value if the result would overflow. */ +struct timeval +make_timeval (struct timespec t) +{ + struct timeval tv; + tv.tv_sec = t.tv_sec; + tv.tv_usec = t.tv_nsec / 1000; + + if (t.tv_nsec % 1000 != 0) + { + if (tv.tv_usec < 999999) + tv.tv_usec++; + else if (tv.tv_sec < TIME_T_MAX) + { + tv.tv_sec++; + tv.tv_usec = 0; + } + } + + return tv; +} + +/* Yield A's UTC offset, or an unspecified value if unknown. */ +static long int +tm_gmtoff (struct tm *a) +{ +#if HAVE_TM_GMTOFF + return a->tm_gmtoff; +#else + return 0; +#endif +} + +/* Yield A - B, measured in seconds. + This function is copied from the GNU C Library. */ +static int +tm_diff (struct tm *a, struct tm *b) +{ + /* Compute intervening leap days correctly even if year is negative. + Take care to avoid int overflow in leap day calculations, + but it's OK to assume that A and B are close to each other. */ + int a4 = (a->tm_year >> 2) + (TM_YEAR_BASE >> 2) - ! (a->tm_year & 3); + int b4 = (b->tm_year >> 2) + (TM_YEAR_BASE >> 2) - ! (b->tm_year & 3); + int a100 = a4 / 25 - (a4 % 25 < 0); + int b100 = b4 / 25 - (b4 % 25 < 0); + int a400 = a100 >> 2; + int b400 = b100 >> 2; + int intervening_leap_days = (a4 - b4) - (a100 - b100) + (a400 - b400); + int years = a->tm_year - b->tm_year; + int days = (365 * years + intervening_leap_days + + (a->tm_yday - b->tm_yday)); + return (60 * (60 * (24 * days + (a->tm_hour - b->tm_hour)) + + (a->tm_min - b->tm_min)) + + (a->tm_sec - b->tm_sec)); +} + +enum { tzeqlen = sizeof "TZ=" - 1 }; + +/* Time zones equivalent to current local time and to UTC, respectively. */ +static timezone_t local_tz; +static timezone_t const utc_tz = 0; + +static struct tm * +emacs_localtime_rz (timezone_t tz, time_t const *t, struct tm *tm) +{ + tm = localtime_rz (tz, t, tm); + if (!tm && errno == ENOMEM) + memory_full (SIZE_MAX); + return tm; +} + +static _Noreturn void +invalid_time_zone_specification (Lisp_Object zone) +{ + xsignal2 (Qerror, build_string ("Invalid time zone specification"), zone); +} + +/* Free a timezone, except do not free the time zone for local time. + Freeing utc_tz is also a no-op. */ +static void +xtzfree (timezone_t tz) +{ + if (tz != local_tz) + tzfree (tz); +} + +/* Convert the Lisp time zone rule ZONE to a timezone_t object. + The returned value either is 0, or is LOCAL_TZ, or is newly allocated. + If SETTZ, set Emacs local time to the time zone rule; otherwise, + the caller should eventually pass the returned value to xtzfree. */ +static timezone_t +tzlookup (Lisp_Object zone, bool settz) +{ + static char const tzbuf_format[] = "<%+.*"pI"d>%s%"pI"d:%02d:%02d"; + char const *trailing_tzbuf_format = tzbuf_format + sizeof "<%+.*"pI"d" - 1; + char tzbuf[sizeof tzbuf_format + 2 * INT_STRLEN_BOUND (EMACS_INT)]; + char const *zone_string; + timezone_t new_tz; + + if (NILP (zone)) + return local_tz; + else if (EQ (zone, Qt) || EQ (zone, make_fixnum (0))) + { + zone_string = "UTC0"; + new_tz = utc_tz; + } + else + { + bool plain_integer = FIXNUMP (zone); + + if (EQ (zone, Qwall)) + zone_string = 0; + else if (STRINGP (zone)) + zone_string = SSDATA (ENCODE_SYSTEM (zone)); + else if (plain_integer || (CONSP (zone) && FIXNUMP (XCAR (zone)) + && CONSP (XCDR (zone)))) + { + Lisp_Object abbr UNINIT; + if (!plain_integer) + { + abbr = XCAR (XCDR (zone)); + zone = XCAR (zone); + } + + EMACS_INT abszone = eabs (XFIXNUM (zone)), hour = abszone / (60 * 60); + int hour_remainder = abszone % (60 * 60); + int min = hour_remainder / 60, sec = hour_remainder % 60; + + if (plain_integer) + { + int prec = 2; + EMACS_INT numzone = hour; + if (hour_remainder != 0) + { + prec += 2, numzone = 100 * numzone + min; + if (sec != 0) + prec += 2, numzone = 100 * numzone + sec; + } + sprintf (tzbuf, tzbuf_format, prec, + XFIXNUM (zone) < 0 ? -numzone : numzone, + &"-"[XFIXNUM (zone) < 0], hour, min, sec); + zone_string = tzbuf; + } + else + { + AUTO_STRING (leading, "<"); + AUTO_STRING_WITH_LEN (trailing, tzbuf, + sprintf (tzbuf, trailing_tzbuf_format, + &"-"[XFIXNUM (zone) < 0], + hour, min, sec)); + zone_string = SSDATA (concat3 (leading, ENCODE_SYSTEM (abbr), + trailing)); + } + } + else + invalid_time_zone_specification (zone); + + new_tz = tzalloc (zone_string); + + if (HAVE_TZALLOC_BUG && !new_tz && errno != ENOMEM && plain_integer + && XFIXNUM (zone) % (60 * 60) == 0) + { + /* tzalloc mishandles POSIX strings; fall back on tzdb if + possible (Bug#30738). */ + sprintf (tzbuf, "Etc/GMT%+"pI"d", - (XFIXNUM (zone) / (60 * 60))); + new_tz = tzalloc (zone_string); + } + + if (!new_tz) + { + if (errno == ENOMEM) + memory_full (SIZE_MAX); + invalid_time_zone_specification (zone); + } + } + + if (settz) + { + block_input (); + emacs_setenv_TZ (zone_string); + tzset (); + timezone_t old_tz = local_tz; + local_tz = new_tz; + tzfree (old_tz); + unblock_input (); + } + + return new_tz; +} + +void +init_timefns (bool dumping) +{ +#ifndef CANNOT_DUMP + /* A valid but unlikely setting for the TZ environment variable. + It is OK (though a bit slower) if the user chooses this value. */ + static char dump_tz_string[] = "TZ=UtC0"; + + /* When just dumping out, set the time zone to a known unlikely value + and skip the rest of this function. */ + if (dumping) + { + xputenv (dump_tz_string); + tzset (); + return; + } +#endif + + char *tz = getenv ("TZ"); + +#if !defined CANNOT_DUMP + /* If the execution TZ happens to be the same as the dump TZ, + change it to some other value and then change it back, + to force the underlying implementation to reload the TZ info. + This is needed on implementations that load TZ info from files, + since the TZ file contents may differ between dump and execution. */ + if (tz && strcmp (tz, &dump_tz_string[tzeqlen]) == 0) + { + ++*tz; + tzset (); + --*tz; + } +#endif + + /* Set the time zone rule now, so that the call to putenv is done + before multiple threads are active. */ + tzlookup (tz ? build_string (tz) : Qwall, true); +} + +/* Report that a time value is out of range for Emacs. */ +void +time_overflow (void) +{ + error ("Specified time is not representable"); +} + +static _Noreturn void +time_error (int err) +{ + switch (err) + { + case ENOMEM: memory_full (SIZE_MAX); + case EOVERFLOW: time_overflow (); + default: error ("Invalid time specification"); + } +} + +static _Noreturn void +invalid_hz (Lisp_Object hz) +{ + xsignal2 (Qerror, build_string ("Invalid time frequency"), hz); +} + +/* Return the upper part of the time T (everything but the bottom 16 bits). */ +static Lisp_Object +hi_time (time_t t) +{ + return INT_TO_INTEGER (t >> LO_TIME_BITS); +} + +/* Return the bottom bits of the time T. */ +static Lisp_Object +lo_time (time_t t) +{ + return make_fixnum (t & ((1 << LO_TIME_BITS) - 1)); +} + +/* Convert T into an Emacs time *RESULT, truncating toward minus infinity. + Return zero if successful, an error number otherwise. */ +static int +decode_float_time (double t, struct lisp_time *result) +{ + if (!isfinite (t)) + return isnan (t) ? EINVAL : EOVERFLOW; + /* Actual hz unknown; guess TIMESPEC_HZ. */ + mpz_set_d (mpz[1], t); + mpz_set_si (mpz[0], floor ((t - trunc (t)) * TIMESPEC_HZ)); + mpz_addmul_ui (mpz[0], mpz[1], TIMESPEC_HZ); + result->ticks = make_integer_mpz (); + result->hz = timespec_hz; + return 0; +} + +/* Compute S + NS/TIMESPEC_HZ as a double. + Calls to this function suffer from double-rounding; + work around some of the problem by using long double. */ +static double +s_ns_to_double (long double s, long double ns) +{ + return s + ns / TIMESPEC_HZ; +} + +/* Make a 4-element timestamp (HI LO US PS) from TICKS and HZ. + Drop any excess precision. */ +static Lisp_Object +ticks_hz_list4 (Lisp_Object ticks, Lisp_Object hz) +{ + mpz_t *zticks = bignum_integer (&mpz[0], ticks); +#if FASTER_TIMEFNS && TRILLION <= ULONG_MAX + mpz_mul_ui (mpz[0], *zticks, TRILLION); +#else + mpz_mul (mpz[0], *zticks, ztrillion); +#endif + mpz_fdiv_q (mpz[0], mpz[0], *bignum_integer (&mpz[1], hz)); +#if FASTER_TIMEFNS && TRILLION <= ULONG_MAX + unsigned long int fullps = mpz_fdiv_q_ui (mpz[0], mpz[0], TRILLION); + int us = fullps / 1000000; + int ps = fullps % 1000000; +#else + mpz_fdiv_qr (mpz[0], mpz[1], mpz[0], ztrillion); + int ps = mpz_fdiv_q_ui (mpz[1], mpz[1], 1000000); + int us = mpz_get_ui (mpz[1]); +#endif + unsigned long ulo = mpz_get_ui (mpz[0]); + if (mpz_sgn (mpz[0]) < 0) + ulo = -ulo; + int lo = ulo & ((1 << LO_TIME_BITS) - 1); + mpz_fdiv_q_2exp (mpz[0], mpz[0], LO_TIME_BITS); + return list4 (make_integer_mpz (), make_fixnum (lo), + make_fixnum (us), make_fixnum (ps)); +} + +/* Set ROP to T. */ +static void +mpz_set_time (mpz_t rop, time_t t) +{ + if (EXPR_SIGNED (t)) + mpz_set_intmax (rop, t); + else + mpz_set_uintmax (rop, t); +} + +/* Store into mpz[0] a clock tick count for T, assuming a + TIMESPEC_HZ-frequency clock. Use mpz[1] as a temp. */ +static void +timespec_mpz (struct timespec t) +{ + mpz_set_ui (mpz[0], t.tv_nsec); + mpz_set_time (mpz[1], t.tv_sec); + mpz_addmul_ui (mpz[0], mpz[1], TIMESPEC_HZ); +} + +/* Convert T to a Lisp integer counting TIMESPEC_HZ ticks. */ +static Lisp_Object +timespec_ticks (struct timespec t) +{ + intmax_t accum; + if (FASTER_TIMEFNS + && !INT_MULTIPLY_WRAPV (t.tv_sec, TIMESPEC_HZ, &accum) + && !INT_ADD_WRAPV (t.tv_nsec, accum, &accum)) + return make_int (accum); + timespec_mpz (t); + return make_integer_mpz (); +} + +/* Convert T to a Lisp integer counting HZ ticks, taking the floor. + Assume T is valid, but check HZ. */ +static Lisp_Object +time_hz_ticks (time_t t, Lisp_Object hz) +{ + if (FIXNUMP (hz)) + { + if (XFIXNUM (hz) <= 0) + invalid_hz (hz); + intmax_t ticks; + if (FASTER_TIMEFNS && !INT_MULTIPLY_WRAPV (t, XFIXNUM (hz), &ticks)) + return make_int (ticks); + } + else if (! (BIGNUMP (hz) && 0 < mpz_sgn (XBIGNUM (hz)->value))) + invalid_hz (hz); + + mpz_set_time (mpz[0], t); + mpz_mul (mpz[0], mpz[0], *bignum_integer (&mpz[1], hz)); + return make_integer_mpz (); +} +static Lisp_Object +lisp_time_hz_ticks (struct lisp_time t, Lisp_Object hz) +{ + if (FASTER_TIMEFNS && EQ (t.hz, hz)) + return t.ticks; + if (FIXNUMP (hz)) + { + if (XFIXNUM (hz) <= 0) + invalid_hz (hz); + intmax_t ticks; + if (FASTER_TIMEFNS && FIXNUMP (t.ticks) && FIXNUMP (t.hz) + && !INT_MULTIPLY_WRAPV (XFIXNUM (t.ticks), XFIXNUM (hz), &ticks)) + return make_int (ticks / XFIXNUM (t.hz) + - (ticks % XFIXNUM (t.hz) < 0)); + } + else if (! (BIGNUMP (hz) && 0 < mpz_sgn (XBIGNUM (hz)->value))) + invalid_hz (hz); + + mpz_mul (mpz[0], + *bignum_integer (&mpz[0], t.ticks), + *bignum_integer (&mpz[1], hz)); + mpz_fdiv_q (mpz[0], mpz[0], *bignum_integer (&mpz[1], t.hz)); + return make_integer_mpz (); +} + +/* Convert T to a Lisp integer counting seconds, taking the floor. */ +static Lisp_Object +lisp_time_seconds (struct lisp_time t) +{ + if (!FASTER_TIMEFNS) + return lisp_time_hz_ticks (t, make_fixnum (1)); + if (FIXNUMP (t.ticks) && FIXNUMP (t.hz)) + return make_fixnum (XFIXNUM (t.ticks) / XFIXNUM (t.hz) + - (XFIXNUM (t.ticks) % XFIXNUM (t.hz) < 0)); + mpz_fdiv_q (mpz[0], + *bignum_integer (&mpz[0], t.ticks), + *bignum_integer (&mpz[1], t.hz)); + return make_integer_mpz (); +} + +/* Convert T to a Lisp timestamp. */ +Lisp_Object +make_lisp_time (struct timespec t) +{ + if (CURRENT_TIME_LIST) + { + time_t s = t.tv_sec; + int ns = t.tv_nsec; + return list4 (hi_time (s), lo_time (s), + make_fixnum (ns / 1000), make_fixnum (ns % 1000 * 1000)); + } + else + return Fcons (timespec_ticks (t), timespec_hz); +} + +/* Convert T to a Lisp timestamp. FORM specifies the timestamp format. */ +static Lisp_Object +time_form_stamp (time_t t, Lisp_Object form) +{ + if (NILP (form)) + form = CURRENT_TIME_LIST ? Qlist : Qt; + if (EQ (form, Qlist)) + return list2 (hi_time (t), lo_time (t)); + if (EQ (form, Qt) || EQ (form, Qinteger)) + return INT_TO_INTEGER (t); + return Fcons (time_hz_ticks (t, form), form); +} +static Lisp_Object +lisp_time_form_stamp (struct lisp_time t, Lisp_Object form) +{ + if (NILP (form)) + form = CURRENT_TIME_LIST ? Qlist : Qt; + if (EQ (form, Qlist)) + return ticks_hz_list4 (t.ticks, t.hz); + if (EQ (form, Qinteger)) + return lisp_time_seconds (t); + if (EQ (form, Qt)) + form = t.hz; + return Fcons (lisp_time_hz_ticks (t, form), form); +} + +/* From what should be a valid timestamp (TICKS . HZ), generate the + corresponding time values. + + If RESULT is not null, store into *RESULT the converted time. + Otherwise, store into *DRESULT the number of seconds since the + start of the POSIX Epoch. Unsuccessful calls may or may not store + results. + + Return zero if successful, an error number if (TICKS . HZ) would not + be a valid new-format timestamp. */ +static int +decode_ticks_hz (Lisp_Object ticks, Lisp_Object hz, + struct lisp_time *result, double *dresult) +{ + int ns; + mpz_t *q = &mpz[0]; + + if (! (INTEGERP (ticks) + && ((FIXNUMP (hz) && 0 < XFIXNUM (hz)) + || (BIGNUMP (hz) && 0 < mpz_sgn (XBIGNUM (hz)->value))))) + return EINVAL; + + if (result) + { + result->ticks = ticks; + result->hz = hz; + } + else + { + if (FASTER_TIMEFNS && EQ (hz, timespec_hz)) + { + if (FIXNUMP (ticks)) + { + verify (1 < TIMESPEC_HZ); + EMACS_INT s = XFIXNUM (ticks) / TIMESPEC_HZ; + ns = XFIXNUM (ticks) % TIMESPEC_HZ; + if (ns < 0) + s--, ns += TIMESPEC_HZ; + *dresult = s_ns_to_double (s, ns); + return 0; + } + ns = mpz_fdiv_q_ui (*q, XBIGNUM (ticks)->value, TIMESPEC_HZ); + } + else if (FASTER_TIMEFNS && EQ (hz, make_fixnum (1))) + { + ns = 0; + if (FIXNUMP (ticks)) + { + *dresult = XFIXNUM (ticks); + return 0; + } + q = &XBIGNUM (ticks)->value; + } + else + { + mpz_mul_ui (*q, *bignum_integer (&mpz[1], ticks), TIMESPEC_HZ); + mpz_fdiv_q (*q, *q, *bignum_integer (&mpz[1], hz)); + ns = mpz_fdiv_q_ui (*q, *q, TIMESPEC_HZ); + } + + *dresult = s_ns_to_double (mpz_get_d (*q), ns); + } + + return 0; +} + +/* Lisp timestamp classification. */ +enum timeform + { + TIMEFORM_INVALID = 0, + TIMEFORM_HI_LO, /* seconds in the form (HI << LO_TIME_BITS) + LO. */ + TIMEFORM_HI_LO_US, /* seconds plus microseconds (HI LO US) */ + TIMEFORM_NIL, /* current time in nanoseconds */ + TIMEFORM_HI_LO_US_PS, /* seconds plus micro and picoseconds (HI LO US PS) */ + TIMEFORM_FLOAT, /* time as a float */ + TIMEFORM_TICKS_HZ /* fractional time: HI is ticks, LO is ticks per second */ + }; + +/* From the valid form FORM and the time components HIGH, LOW, USEC + and PSEC, generate the corresponding time value. If LOW is + floating point, the other components should be zero and FORM should + not be TIMEFORM_TICKS_HZ. + + If RESULT is not null, store into *RESULT the converted time. + Otherwise, store into *DRESULT the number of seconds since the + start of the POSIX Epoch. Unsuccessful calls may or may not store + results. + + Return zero if successful, an error number otherwise. */ +static int +decode_time_components (enum timeform form, + Lisp_Object high, Lisp_Object low, + Lisp_Object usec, Lisp_Object psec, + struct lisp_time *result, double *dresult) +{ + switch (form) + { + case TIMEFORM_INVALID: + return EINVAL; + + case TIMEFORM_TICKS_HZ: + return decode_ticks_hz (high, low, result, dresult); + + case TIMEFORM_FLOAT: + { + double t = XFLOAT_DATA (low); + if (result) + return decode_float_time (t, result); + else + { + *dresult = t; + return 0; + } + } + + case TIMEFORM_NIL: + { + struct timespec now = current_timespec (); + if (result) + { + result->ticks = timespec_ticks (now); + result->hz = timespec_hz; + } + else + *dresult = s_ns_to_double (now.tv_sec, now.tv_nsec); + return 0; + } + + default: + break; + } + + if (! (INTEGERP (high) && INTEGERP (low) + && FIXNUMP (usec) && FIXNUMP (psec))) + return EINVAL; + EMACS_INT us = XFIXNUM (usec); + EMACS_INT ps = XFIXNUM (psec); + + /* Normalize out-of-range lower-order components by carrying + each overflow into the next higher-order component. */ + us += ps / 1000000 - (ps % 1000000 < 0); + mpz_set_intmax (mpz[0], us / 1000000 - (us % 1000000 < 0)); + mpz_add (mpz[0], mpz[0], *bignum_integer (&mpz[1], low)); + mpz_addmul_ui (mpz[0], *bignum_integer (&mpz[1], high), 1 << LO_TIME_BITS); + ps = ps % 1000000 + 1000000 * (ps % 1000000 < 0); + us = us % 1000000 + 1000000 * (us % 1000000 < 0); + + if (result) + { + switch (form) + { + case TIMEFORM_HI_LO: + /* Floats and nil were handled above, so it was an integer. */ + result->hz = make_fixnum (1); + break; + + case TIMEFORM_HI_LO_US: + mpz_mul_ui (mpz[0], mpz[0], 1000000); + mpz_add_ui (mpz[0], mpz[0], us); + result->hz = make_fixnum (1000000); + break; + + case TIMEFORM_HI_LO_US_PS: + mpz_mul_ui (mpz[0], mpz[0], 1000000); + mpz_add_ui (mpz[0], mpz[0], us); + mpz_mul_ui (mpz[0], mpz[0], 1000000); + mpz_add_ui (mpz[0], mpz[0], ps); + result->hz = trillion; + break; + + default: + eassume (false); + } + result->ticks = make_integer_mpz (); + } + else + *dresult = mpz_get_d (mpz[0]) + (us * 1e6L + ps) / 1e12L; + + return 0; +} + +enum { DECODE_SECS_ONLY = WARN_OBSOLETE_TIMESTAMPS + 1 }; + +/* Decode a Lisp timestamp SPECIFIED_TIME that represents a time. + + FLAGS specifies conversion flags. If FLAGS & DECODE_SECS_ONLY, + ignore and do not validate any sub-second components of an + old-format SPECIFIED_TIME. If FLAGS & WARN_OBSOLETE_TIMESTAMPS, + diagnose what could be obsolete (HIGH . LOW) timestamps. + + If PFORM is not null, store into *PFORM the form of SPECIFIED-TIME. + If RESULT is not null, store into *RESULT the converted time; + otherwise, store into *DRESULT the number of seconds since the + start of the POSIX Epoch. Unsuccessful calls may or may not store + results. + + Signal an error if unsuccessful. */ +static void +decode_lisp_time (Lisp_Object specified_time, int flags, + enum timeform *pform, + struct lisp_time *result, double *dresult) +{ + Lisp_Object high = make_fixnum (0); + Lisp_Object low = specified_time; + Lisp_Object usec = make_fixnum (0); + Lisp_Object psec = make_fixnum (0); + enum timeform form = TIMEFORM_HI_LO; + + if (NILP (specified_time)) + form = TIMEFORM_NIL; + else if (FLOATP (specified_time)) + form = TIMEFORM_FLOAT; + else if (CONSP (specified_time)) + { + high = XCAR (specified_time); + low = XCDR (specified_time); + if (CONSP (low)) + { + Lisp_Object low_tail = XCDR (low); + low = XCAR (low); + if (! (flags & DECODE_SECS_ONLY)) + { + if (CONSP (low_tail)) + { + usec = XCAR (low_tail); + low_tail = XCDR (low_tail); + if (CONSP (low_tail)) + { + psec = XCAR (low_tail); + form = TIMEFORM_HI_LO_US_PS; + } + else + form = TIMEFORM_HI_LO_US; + } + else if (!NILP (low_tail)) + { + usec = low_tail; + form = TIMEFORM_HI_LO_US; + } + } + } + else + { + if (flags & WARN_OBSOLETE_TIMESTAMPS + && RANGED_FIXNUMP (0, low, (1 << LO_TIME_BITS) - 1)) + message ("obsolete timestamp with cdr %"pI"d", XFIXNUM (low)); + form = TIMEFORM_TICKS_HZ; + } + + /* Require LOW to be an integer, as otherwise the computation + would be considerably trickier. */ + if (! INTEGERP (low)) + form = TIMEFORM_INVALID; + } + + if (pform) + *pform = form; + int err = decode_time_components (form, high, low, usec, psec, + result, dresult); + if (err) + time_error (err); +} + +/* Convert Z to time_t, returning true if it fits. */ +static bool +mpz_time (mpz_t const z, time_t *t) +{ + if (TYPE_SIGNED (time_t)) + { + intmax_t i; + if (! (mpz_to_intmax (z, &i) && TIME_T_MIN <= i && i <= TIME_T_MAX)) + return false; + *t = i; + } + else + { + uintmax_t i; + if (! (mpz_to_uintmax (z, &i) && i <= TIME_T_MAX)) + return false; + *t = i; + } + return true; +} + +/* Convert T to struct timespec, returning an invalid timespec + if T does not fit. */ +static struct timespec +lisp_to_timespec (struct lisp_time t) +{ + struct timespec result = invalid_timespec (); + int ns; + mpz_t *q = &mpz[0]; + + if (FASTER_TIMEFNS && EQ (t.hz, timespec_hz)) + { + if (FIXNUMP (t.ticks)) + { + EMACS_INT s = XFIXNUM (t.ticks) / TIMESPEC_HZ; + ns = XFIXNUM (t.ticks) % TIMESPEC_HZ; + if (ns < 0) + s--, ns += TIMESPEC_HZ; + if ((TYPE_SIGNED (time_t) ? TIME_T_MIN <= s : 0 <= s) + && s <= TIME_T_MAX) + { + result.tv_sec = s; + result.tv_nsec = ns; + } + return result; + } + else + ns = mpz_fdiv_q_ui (*q, XBIGNUM (t.ticks)->value, TIMESPEC_HZ); + } + else if (FASTER_TIMEFNS && EQ (t.hz, make_fixnum (1))) + { + ns = 0; + if (FIXNUMP (t.ticks)) + { + EMACS_INT s = XFIXNUM (t.ticks); + if ((TYPE_SIGNED (time_t) ? TIME_T_MIN <= s : 0 <= s) + && s <= TIME_T_MAX) + { + result.tv_sec = s; + result.tv_nsec = ns; + } + return result; + } + else + q = &XBIGNUM (t.ticks)->value; + } + else + { + mpz_mul_ui (*q, *bignum_integer (q, t.ticks), TIMESPEC_HZ); + mpz_fdiv_q (*q, *q, *bignum_integer (&mpz[1], t.hz)); + ns = mpz_fdiv_q_ui (*q, *q, TIMESPEC_HZ); + } + + /* With some versions of MinGW, tv_sec is a 64-bit type, whereas + time_t is a 32-bit type. */ + time_t sec; + if (mpz_time (*q, &sec)) + { + result.tv_sec = sec; + result.tv_nsec = ns; + } + return result; +} + +/* Convert (HIGH LOW USEC PSEC) to struct timespec. + Return true if successful. */ +bool +list4_to_timespec (Lisp_Object high, Lisp_Object low, + Lisp_Object usec, Lisp_Object psec, + struct timespec *result) +{ + struct lisp_time t; + if (decode_time_components (TIMEFORM_HI_LO_US_PS, high, low, usec, psec, + &t, 0)) + return false; + *result = lisp_to_timespec (t); + return timespec_valid_p (*result); +} + +/* Decode a Lisp list SPECIFIED_TIME that represents a time. + If SPECIFIED_TIME is nil, use the current time. + Signal an error if SPECIFIED_TIME does not represent a time. */ +static struct lisp_time +lisp_time_struct (Lisp_Object specified_time, enum timeform *pform) +{ + struct lisp_time t; + decode_lisp_time (specified_time, WARN_OBSOLETE_TIMESTAMPS, pform, &t, 0); + return t; +} + +/* Decode a Lisp list SPECIFIED_TIME that represents a time. + Discard any low-order (sub-ns) resolution. + If SPECIFIED_TIME is nil, use the current time. + Signal an error if SPECIFIED_TIME does not represent a timespec. */ +struct timespec +lisp_time_argument (Lisp_Object specified_time) +{ + struct lisp_time lt = lisp_time_struct (specified_time, 0); + struct timespec t = lisp_to_timespec (lt); + if (! timespec_valid_p (t)) + time_overflow (); + return t; +} + +/* Like lisp_time_argument, except decode only the seconds part, and + do not check the subseconds part. */ +static time_t +lisp_seconds_argument (Lisp_Object specified_time) +{ + int flags = WARN_OBSOLETE_TIMESTAMPS | DECODE_SECS_ONLY; + struct lisp_time lt; + decode_lisp_time (specified_time, flags, 0, <, 0); + struct timespec t = lisp_to_timespec (lt); + if (! timespec_valid_p (t)) + time_overflow (); + return t.tv_sec; +} + +/* Given Lisp operands A and B, add their values, and return the + result as a Lisp timestamp that is in (TICKS . HZ) form if either A + or B are in that form, (HI LO US PS) form otherwise. Subtract + instead of adding if SUBTRACT. */ +static Lisp_Object +time_arith (Lisp_Object a, Lisp_Object b, bool subtract) +{ + if (FLOATP (a) && !isfinite (XFLOAT_DATA (a))) + { + double da = XFLOAT_DATA (a); + double db = XFLOAT_DATA (Ffloat_time (b)); + return make_float (subtract ? da - db : da + db); + } + if (FLOATP (b) && !isfinite (XFLOAT_DATA (b))) + return subtract ? make_float (-XFLOAT_DATA (b)) : b; + + enum timeform aform, bform; + struct lisp_time ta = lisp_time_struct (a, &aform); + struct lisp_time tb = lisp_time_struct (b, &bform); + Lisp_Object ticks, hz; + + if (FASTER_TIMEFNS && EQ (ta.hz, tb.hz)) + { + hz = ta.hz; + if (FIXNUMP (ta.ticks) && FIXNUMP (tb.ticks)) + ticks = make_int (subtract + ? XFIXNUM (ta.ticks) - XFIXNUM (tb.ticks) + : XFIXNUM (ta.ticks) + XFIXNUM (tb.ticks)); + else + { + (subtract ? mpz_sub : mpz_add) + (mpz[0], + *bignum_integer (&mpz[0], ta.ticks), + *bignum_integer (&mpz[1], tb.ticks)); + ticks = make_integer_mpz (); + } + } + else + { + /* The plan is to decompose ta into na/da and tb into nb/db. + Start by computing da and db. */ + mpz_t *da = bignum_integer (&mpz[1], ta.hz); + mpz_t *db = bignum_integer (&mpz[2], tb.hz); + + /* The plan is to compute (na * (db/g) + nb * (da/g)) / lcm (da, db) + where g = gcd (da, db). Start by computing g. */ + mpz_t *g = &mpz[3]; + mpz_gcd (*g, *da, *db); + + /* fa = da/g, fb = db/g. */ + mpz_t *fa = &mpz[1], *fb = &mpz[3]; + mpz_tdiv_q (*fa, *da, *g); + mpz_tdiv_q (*fb, *db, *g); + + /* FIXME: Maybe omit need for extra temp by computing fa * db here? */ + + /* hz = fa * db. This is equal to lcm (da, db). */ + mpz_mul (mpz[0], *fa, *db); + hz = make_integer_mpz (); + + /* ticks = (fb * na) OPER (fa * nb), where OPER is + or -. + OP is the multiply-add or multiply-sub form of OPER. */ + mpz_t *na = bignum_integer (&mpz[0], ta.ticks); + mpz_mul (mpz[0], *fb, *na); + mpz_t *nb = bignum_integer (&mpz[3], tb.ticks); + (subtract ? mpz_submul : mpz_addmul) (mpz[0], *fa, *nb); + ticks = make_integer_mpz (); + } + + /* Return the (TICKS . HZ) form if either argument is that way, + otherwise the (HI LO US PS) form for backward compatibility. */ + return (aform == TIMEFORM_TICKS_HZ || bform == TIMEFORM_TICKS_HZ + ? Fcons (ticks, hz) + : ticks_hz_list4 (ticks, hz)); +} + +DEFUN ("time-add", Ftime_add, Stime_add, 2, 2, 0, + doc: /* Return the sum of two time values A and B, as a time value. +See `format-time-string' for the various forms of a time value. +For example, nil stands for the current time. */) + (Lisp_Object a, Lisp_Object b) +{ + return time_arith (a, b, false); +} + +DEFUN ("time-subtract", Ftime_subtract, Stime_subtract, 2, 2, 0, + doc: /* Return the difference between two time values A and B, as a time value. +You can use `float-time' to convert the difference into elapsed seconds. +See `format-time-string' for the various forms of a time value. +For example, nil stands for the current time. */) + (Lisp_Object a, Lisp_Object b) +{ + return time_arith (a, b, true); +} + +/* Return negative, 0, positive if a < b, a == b, a > b respectively. + Return positive if either a or b is a NaN; this is good enough + for the current callers. */ +static int +time_cmp (Lisp_Object a, Lisp_Object b) +{ + if ((FLOATP (a) && !isfinite (XFLOAT_DATA (a))) + || (FLOATP (b) && !isfinite (XFLOAT_DATA (b)))) + { + double da = FLOATP (a) ? XFLOAT_DATA (a) : 0; + double db = FLOATP (b) ? XFLOAT_DATA (b) : 0; + return da < db ? -1 : da != db; + } + + struct lisp_time ta = lisp_time_struct (a, 0); + + /* Compare nil to nil correctly, and other eq values while we're at it. + Compare here rather than earlier, to handle NaNs and check formats. */ + if (EQ (a, b)) + return 0; + + struct lisp_time tb = lisp_time_struct (b, 0); + mpz_t *za = bignum_integer (&mpz[0], ta.ticks); + mpz_t *zb = bignum_integer (&mpz[1], tb.ticks); + if (! (FASTER_TIMEFNS && EQ (ta.hz, tb.hz))) + { + /* This could be sped up by looking at the signs, sizes, and + number of bits of the two sides; see how GMP does mpq_cmp. + It may not be worth the trouble here, though. */ + mpz_mul (mpz[0], *za, *bignum_integer (&mpz[2], tb.hz)); + mpz_mul (mpz[1], *zb, *bignum_integer (&mpz[2], ta.hz)); + za = &mpz[0]; + zb = &mpz[1]; + } + return mpz_cmp (*za, *zb); +} + +DEFUN ("time-less-p", Ftime_less_p, Stime_less_p, 2, 2, 0, + doc: /* Return non-nil if time value A is less than time value B. +See `format-time-string' for the various forms of a time value. +For example, nil stands for the current time. */) + (Lisp_Object a, Lisp_Object b) +{ + return time_cmp (a, b) < 0 ? Qt : Qnil; +} + +DEFUN ("time-equal-p", Ftime_equal_p, Stime_equal_p, 2, 2, 0, + doc: /* Return non-nil if A and B are equal time values. +See `format-time-string' for the various forms of a time value. */) + (Lisp_Object a, Lisp_Object b) +{ + return time_cmp (a, b) == 0 ? Qt : Qnil; +} + + +DEFUN ("float-time", Ffloat_time, Sfloat_time, 0, 1, 0, + doc: /* Return the current time, as a float number of seconds since the epoch. +If SPECIFIED-TIME is given, it is a time value to convert to float +instead of the current time. See `format-time-string' for the various +forms of a time value. + +WARNING: Since the result is floating point, it may not be exact. +If precise time stamps are required, use either `encode-time', +or (if you need time as a string) `format-time-string'. */) + (Lisp_Object specified_time) +{ + double t; + decode_lisp_time (specified_time, 0, 0, 0, &t); + return make_float (t); +} + +/* Write information into buffer S of size MAXSIZE, according to the + FORMAT of length FORMAT_LEN, using time information taken from *TP. + Use the time zone specified by TZ. + Use NS as the number of nanoseconds in the %N directive. + Return the number of bytes written, not including the terminating + '\0'. If S is NULL, nothing will be written anywhere; so to + determine how many bytes would be written, use NULL for S and + ((size_t) -1) for MAXSIZE. + + This function behaves like nstrftime, except it allows null + bytes in FORMAT and it does not support nanoseconds. */ +static size_t +emacs_nmemftime (char *s, size_t maxsize, const char *format, + size_t format_len, const struct tm *tp, timezone_t tz, int ns) +{ + size_t total = 0; + + /* Loop through all the null-terminated strings in the format + argument. Normally there's just one null-terminated string, but + there can be arbitrarily many, concatenated together, if the + format contains '\0' bytes. nstrftime stops at the first + '\0' byte so we must invoke it separately for each such string. */ + for (;;) + { + size_t len; + size_t result; + + if (s) + s[0] = '\1'; + + result = nstrftime (s, maxsize, format, tp, tz, ns); + + if (s) + { + if (result == 0 && s[0] != '\0') + return 0; + s += result + 1; + } + + maxsize -= result + 1; + total += result; + len = strlen (format); + if (len == format_len) + return total; + total++; + format += len + 1; + format_len -= len + 1; + } +} + +static Lisp_Object +format_time_string (char const *format, ptrdiff_t formatlen, + struct timespec t, Lisp_Object zone, struct tm *tmp) +{ + char buffer[4000]; + char *buf = buffer; + ptrdiff_t size = sizeof buffer; + size_t len; + int ns = t.tv_nsec; + USE_SAFE_ALLOCA; + + timezone_t tz = tzlookup (zone, false); + /* On some systems, like 32-bit MinGW, tv_sec of struct timespec is + a 64-bit type, but time_t is a 32-bit type. emacs_localtime_rz + expects a pointer to time_t value. */ + time_t tsec = t.tv_sec; + tmp = emacs_localtime_rz (tz, &tsec, tmp); + if (! tmp) + { + int localtime_errno = errno; + xtzfree (tz); + time_error (localtime_errno); + } + synchronize_system_time_locale (); + + while (true) + { + buf[0] = '\1'; + len = emacs_nmemftime (buf, size, format, formatlen, tmp, tz, ns); + if ((0 < len && len < size) || (len == 0 && buf[0] == '\0')) + break; + + /* Buffer was too small, so make it bigger and try again. */ + len = emacs_nmemftime (NULL, SIZE_MAX, format, formatlen, tmp, tz, ns); + if (STRING_BYTES_BOUND <= len) + { + xtzfree (tz); + string_overflow (); + } + size = len + 1; + buf = SAFE_ALLOCA (size); + } + + xtzfree (tz); + AUTO_STRING_WITH_LEN (bufstring, buf, len); + Lisp_Object result = code_convert_string_norecord (bufstring, + Vlocale_coding_system, 0); + SAFE_FREE (); + return result; +} + +DEFUN ("format-time-string", Fformat_time_string, Sformat_time_string, 1, 3, 0, + doc: /* Use FORMAT-STRING to format the time value TIME. +A time value that is omitted or nil stands for the current time, +a number stands for that many seconds, an integer pair (TICKS . HZ) +stands for TICKS/HZ seconds, and an integer list (HI LO US PS) stands +for HI*2**16 + LO + US/10**6 + PS/10**12 seconds. This function +treats seconds as time since the epoch of 1970-01-01 00:00:00 UTC. + +The optional ZONE is omitted or nil for Emacs local time, t for +Universal Time, `wall' for system wall clock time, or a string as in +the TZ environment variable. It can also be a list (as from +`current-time-zone') or an integer (as from `decode-time') applied +without consideration for daylight saving time. + +The value is a copy of FORMAT-STRING, but with certain constructs replaced +by text that describes the specified date and time in TIME: + +%Y is the year, %y within the century, %C the century. +%G is the year corresponding to the ISO week, %g within the century. +%m is the numeric month. +%b and %h are the locale's abbreviated month name, %B the full name. + (%h is not supported on MS-Windows.) +%d is the day of the month, zero-padded, %e is blank-padded. +%u is the numeric day of week from 1 (Monday) to 7, %w from 0 (Sunday) to 6. +%a is the locale's abbreviated name of the day of week, %A the full name. +%U is the week number starting on Sunday, %W starting on Monday, + %V according to ISO 8601. +%j is the day of the year. + +%H is the hour on a 24-hour clock, %I is on a 12-hour clock, %k is like %H + only blank-padded, %l is like %I blank-padded. +%p is the locale's equivalent of either AM or PM. +%q is the calendar quarter (1–4). +%M is the minute (00-59). +%S is the second (00-59; 00-60 on platforms with leap seconds) +%s is the number of seconds since 1970-01-01 00:00:00 +0000. +%N is the nanosecond, %6N the microsecond, %3N the millisecond, etc. +%Z is the time zone abbreviation, %z is the numeric form. + +%c is the locale's date and time format. +%x is the locale's "preferred" date format. +%D is like "%m/%d/%y". +%F is the ISO 8601 date format (like "%Y-%m-%d"). + +%R is like "%H:%M", %T is like "%H:%M:%S", %r is like "%I:%M:%S %p". +%X is the locale's "preferred" time format. + +Finally, %n is a newline, %t is a tab, %% is a literal %, and +unrecognized %-sequences stand for themselves. + +Certain flags and modifiers are available with some format controls. +The flags are `_', `-', `^' and `#'. For certain characters X, +%_X is like %X, but padded with blanks; %-X is like %X, +but without padding. %^X is like %X, but with all textual +characters up-cased; %#X is like %X, but with letter-case of +all textual characters reversed. +%NX (where N stands for an integer) is like %X, +but takes up at least N (a number) positions. +The modifiers are `E' and `O'. For certain characters X, +%EX is a locale's alternative version of %X; +%OX is like %X, but uses the locale's number symbols. + +For example, to produce full ISO 8601 format, use "%FT%T%z". + +usage: (format-time-string FORMAT-STRING &optional TIME ZONE) */) + (Lisp_Object format_string, Lisp_Object timeval, Lisp_Object zone) +{ + struct timespec t = lisp_time_argument (timeval); + struct tm tm; + + CHECK_STRING (format_string); + format_string = code_convert_string_norecord (format_string, + Vlocale_coding_system, 1); + return format_time_string (SSDATA (format_string), SBYTES (format_string), + t, zone, &tm); +} + +DEFUN ("decode-time", Fdecode_time, Sdecode_time, 0, 2, 0, + doc: /* Decode a time value as (SEC MINUTE HOUR DAY MONTH YEAR DOW DST UTCOFF). +The optional TIME is the time value to convert. See +`format-time-string' for the various forms of a time value. + +The optional ZONE is omitted or nil for Emacs local time, t for +Universal Time, `wall' for system wall clock time, or a string as in +the TZ environment variable. It can also be a list (as from +`current-time-zone') or an integer (the UTC offset in seconds) applied +without consideration for daylight saving time. + +The list has the following nine members: SEC is an integer between 0 +and 60; SEC is 60 for a leap second, which only some operating systems +support. MINUTE is an integer between 0 and 59. HOUR is an integer +between 0 and 23. DAY is an integer between 1 and 31. MONTH is an +integer between 1 and 12. YEAR is an integer indicating the +four-digit year. DOW is the day of week, an integer between 0 and 6, +where 0 is Sunday. DST is t if daylight saving time is in effect, +nil if it is not in effect, and -1 if daylight saving information is +not available. UTCOFF is an integer indicating the UTC offset in +seconds, i.e., the number of seconds east of Greenwich. (Note that +Common Lisp has different meanings for DOW and UTCOFF.) + +usage: (decode-time &optional TIME ZONE) */) + (Lisp_Object specified_time, Lisp_Object zone) +{ + time_t time_spec = lisp_seconds_argument (specified_time); + struct tm local_tm, gmt_tm; + timezone_t tz = tzlookup (zone, false); + struct tm *tm = emacs_localtime_rz (tz, &time_spec, &local_tm); + int localtime_errno = errno; + xtzfree (tz); + + if (!tm) + time_error (localtime_errno); + if (! (MOST_NEGATIVE_FIXNUM - TM_YEAR_BASE <= local_tm.tm_year + && local_tm.tm_year <= MOST_POSITIVE_FIXNUM - TM_YEAR_BASE)) + time_overflow (); + + /* Avoid overflow when INT_MAX < EMACS_INT_MAX. */ + EMACS_INT tm_year_base = TM_YEAR_BASE; + + return CALLN (Flist, + make_fixnum (local_tm.tm_sec), + make_fixnum (local_tm.tm_min), + make_fixnum (local_tm.tm_hour), + make_fixnum (local_tm.tm_mday), + make_fixnum (local_tm.tm_mon + 1), + make_fixnum (local_tm.tm_year + tm_year_base), + make_fixnum (local_tm.tm_wday), + (local_tm.tm_isdst < 0 ? make_fixnum (-1) + : local_tm.tm_isdst == 0 ? Qnil : Qt), + (HAVE_TM_GMTOFF + ? make_fixnum (tm_gmtoff (&local_tm)) + : gmtime_r (&time_spec, &gmt_tm) + ? make_fixnum (tm_diff (&local_tm, &gmt_tm)) + : Qnil)); +} + +/* Return OBJ - OFFSET, checking that OBJ is a valid fixnum and that + the result is representable as an int. 0 <= OFFSET <= TM_YEAR_BASE. */ +static int +check_tm_member (Lisp_Object obj, int offset) +{ + if (FASTER_TIMEFNS && INT_MAX <= MOST_POSITIVE_FIXNUM - TM_YEAR_BASE) + { + CHECK_FIXNUM (obj); + EMACS_INT n = XFIXNUM (obj); + int i; + if (INT_SUBTRACT_WRAPV (n, offset, &i)) + time_overflow (); + return i; + } + else + { + CHECK_INTEGER (obj); + mpz_sub_ui (mpz[0], *bignum_integer (&mpz[0], obj), offset); + intmax_t i; + if (! (mpz_to_intmax (mpz[0], &i) && INT_MIN <= i && i <= INT_MAX)) + time_overflow (); + return i; + } +} + +DEFUN ("encode-time", Fencode_time, Sencode_time, 1, MANY, 0, + doc: /* Convert optional TIME to a timestamp. +Optional FORM specifies how the returned value should be encoded. +This can act as the reverse operation of `decode-time', which see. + +If TIME is a list (SECOND MINUTE HOUR DAY MONTH YEAR IGNORED DST ZONE) +it is a decoded time in the style of `decode-time', so that (encode-time +(decode-time ...)) works. TIME can also be a time value. +See `format-time-string' for the various forms of a time value. +For example, an omitted TIME stands for the current time. + +If FORM is a positive integer, the time is returned as a pair of +integers (TICKS . FORM), where TICKS is the number of clock ticks and FORM +is the clock frequency in ticks per second. (Currently the positive +integer should be at least 65536 if the returned value is expected to +be given to standard functions expecting Lisp timestamps.) If FORM is +t, the time is returned as (TICKS . PHZ), where PHZ is a platform dependent +clock frequency in ticks per second. If FORM is `integer', the time is +returned as an integer count of seconds. If FORM is `list', the time is +returned as an integer list (HIGH LOW USEC PSEC), where HIGH has the +most significant bits of the seconds, LOW has the least significant 16 +bits, and USEC and PSEC are the microsecond and picosecond counts. +Returned values are rounded toward minus infinity. Although an +omitted or nil FORM currently acts like `list', this is planned to +change, so callers requiring list timestamps should specify `list'. + +As an obsolescent calling convention, if this function is called with +6 or more arguments, the first 6 arguments are SECOND, MINUTE, HOUR, +DAY, MONTH, and YEAR, and specify the components of a decoded time, +where DST assumed to be -1 and FORM is omitted. If there are more +than 6 arguments the *last* argument is used as ZONE and any other +extra arguments are ignored, so that (apply #\\='encode-time +(decode-time ...)) works; otherwise ZONE is assumed to be nil. + +If the input is a decoded time, ZONE is nil for Emacs local time, t +for Universal Time, `wall' for system wall clock time, or a string as +in the TZ environment variable. It can also be a list (as from +`current-time-zone') or an integer (as from `decode-time') applied +without consideration for daylight saving time. + +If the input is a decoded time and ZONE specifies a time zone with +daylight-saving transitions, DST is t for daylight saving time and nil +for standard time. If DST is -1, the daylight saving flag is guessed. + +Out-of-range values for SECOND, MINUTE, HOUR, DAY, or MONTH are allowed; +for example, a DAY of 0 means the day preceding the given month. +Year numbers less than 100 are treated just like other year numbers. +If you want them to stand for years in this century, you must do that yourself. + +Years before 1970 are not guaranteed to work. On some systems, +year values as low as 1901 do work. + +usage: (encode-time &optional TIME FORM &rest OBSOLESCENT-ARGUMENTS) */) + (ptrdiff_t nargs, Lisp_Object *args) +{ + struct tm tm; + Lisp_Object form = Qnil, zone = Qnil; + Lisp_Object a = args[0]; + tm.tm_isdst = -1; + + if (nargs <= 2) + { + if (nargs == 2) + form = args[1]; + Lisp_Object tail = a; + for (int i = 0; i < 9; i++, tail = XCDR (tail)) + if (! CONSP (tail)) + { + struct lisp_time t; + decode_lisp_time (a, 0, 0, &t, 0); + return lisp_time_form_stamp (t, form); + } + tm.tm_sec = check_tm_member (XCAR (a), 0); a = XCDR (a); + tm.tm_min = check_tm_member (XCAR (a), 0); a = XCDR (a); + tm.tm_hour = check_tm_member (XCAR (a), 0); a = XCDR (a); + tm.tm_mday = check_tm_member (XCAR (a), 0); a = XCDR (a); + tm.tm_mon = check_tm_member (XCAR (a), 1); a = XCDR (a); + tm.tm_year = check_tm_member (XCAR (a), TM_YEAR_BASE); a = XCDR (a); + a = XCDR (a); + if (SYMBOLP (XCAR (a))) + tm.tm_isdst = !NILP (XCAR (a)); + a = XCDR (a); + zone = XCAR (a); + } + else if (nargs < 6) + xsignal2 (Qwrong_number_of_arguments, Qencode_time, make_fixnum (nargs)); + else + { + if (6 < nargs) + zone = args[nargs - 1]; + tm.tm_sec = check_tm_member (a, 0); + tm.tm_min = check_tm_member (args[1], 0); + tm.tm_hour = check_tm_member (args[2], 0); + tm.tm_mday = check_tm_member (args[3], 0); + tm.tm_mon = check_tm_member (args[4], 1); + tm.tm_year = check_tm_member (args[5], TM_YEAR_BASE); + } + + timezone_t tz = tzlookup (zone, false); + tm.tm_wday = -1; + time_t value = mktime_z (tz, &tm); + int mktime_errno = errno; + xtzfree (tz); + + if (tm.tm_wday < 0) + time_error (mktime_errno); + + return time_form_stamp (value, form); +} + +DEFUN ("current-time", Fcurrent_time, Scurrent_time, 0, 0, 0, + doc: /* Return the current time, as the number of seconds since 1970-01-01 00:00:00. +The time is returned as a list of integers (HIGH LOW USEC PSEC). +HIGH has the most significant bits of the seconds, while LOW has the +least significant 16 bits. USEC and PSEC are the microsecond and +picosecond counts. Use `encode-time' if you need a particular +timestamp form; for example, (encode-time nil \\='integer) returns the +current time in seconds. */) + (void) +{ + return make_lisp_time (current_timespec ()); +} + +DEFUN ("current-time-string", Fcurrent_time_string, Scurrent_time_string, + 0, 2, 0, + doc: /* Return the current local time, as a human-readable string. +Programs can use this function to decode a time, +since the number of columns in each field is fixed +if the year is in the range 1000-9999. +The format is `Sun Sep 16 01:03:52 1973'. +However, see also the functions `decode-time' and `format-time-string' +which provide a much more powerful and general facility. + +If SPECIFIED-TIME is given, it is the time value to format instead of +the current time. See `format-time-string' for the various forms of a +time value. + +The optional ZONE is omitted or nil for Emacs local time, t for +Universal Time, `wall' for system wall clock time, or a string as in +the TZ environment variable. It can also be a list (as from +`current-time-zone') or an integer (as from `decode-time') applied +without consideration for daylight saving time. */) + (Lisp_Object specified_time, Lisp_Object zone) +{ + time_t value = lisp_seconds_argument (specified_time); + timezone_t tz = tzlookup (zone, false); + + /* Convert to a string in ctime format, except without the trailing + newline, and without the 4-digit year limit. Don't use asctime + or ctime, as they might dump core if the year is outside the + range -999 .. 9999. */ + struct tm tm; + struct tm *tmp = emacs_localtime_rz (tz, &value, &tm); + int localtime_errno = errno; + xtzfree (tz); + if (! tmp) + time_error (localtime_errno); + + static char const wday_name[][4] = + { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" }; + static char const mon_name[][4] = + { "Jan", "Feb", "Mar", "Apr", "May", "Jun", + "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" }; + printmax_t year_base = TM_YEAR_BASE; + char buf[sizeof "Mon Apr 30 12:49:17 " + INT_STRLEN_BOUND (int) + 1]; + int len = sprintf (buf, "%s %s%3d %02d:%02d:%02d %"pMd, + wday_name[tm.tm_wday], mon_name[tm.tm_mon], tm.tm_mday, + tm.tm_hour, tm.tm_min, tm.tm_sec, + tm.tm_year + year_base); + + return make_unibyte_string (buf, len); +} + +DEFUN ("current-time-zone", Fcurrent_time_zone, Scurrent_time_zone, 0, 2, 0, + doc: /* Return the offset and name for the local time zone. +This returns a list of the form (OFFSET NAME). +OFFSET is an integer number of seconds ahead of UTC (east of Greenwich). + A negative value means west of Greenwich. +NAME is a string giving the name of the time zone. +If SPECIFIED-TIME is given, the time zone offset is determined from it +instead of using the current time. The argument should be a Lisp +time value; see `format-time-string' for the various forms of a time +value. + +The optional ZONE is omitted or nil for Emacs local time, t for +Universal Time, `wall' for system wall clock time, or a string as in +the TZ environment variable. It can also be a list (as from +`current-time-zone') or an integer (as from `decode-time') applied +without consideration for daylight saving time. + +Some operating systems cannot provide all this information to Emacs; +in this case, `current-time-zone' returns a list containing nil for +the data it can't find. */) + (Lisp_Object specified_time, Lisp_Object zone) +{ + struct timespec value; + struct tm local_tm, gmt_tm; + Lisp_Object zone_offset, zone_name; + + zone_offset = Qnil; + value = make_timespec (lisp_seconds_argument (specified_time), 0); + zone_name = format_time_string ("%Z", sizeof "%Z" - 1, value, + zone, &local_tm); + + /* gmtime_r expects a pointer to time_t, but tv_sec of struct + timespec on some systems (MinGW) is a 64-bit field. */ + time_t tsec = value.tv_sec; + if (HAVE_TM_GMTOFF || gmtime_r (&tsec, &gmt_tm)) + { + long int offset = (HAVE_TM_GMTOFF + ? tm_gmtoff (&local_tm) + : tm_diff (&local_tm, &gmt_tm)); + zone_offset = make_fixnum (offset); + if (SCHARS (zone_name) == 0) + { + /* No local time zone name is available; use numeric zone instead. */ + long int hour = offset / 3600; + int min_sec = offset % 3600; + int amin_sec = min_sec < 0 ? - min_sec : min_sec; + int min = amin_sec / 60; + int sec = amin_sec % 60; + int min_prec = min_sec ? 2 : 0; + int sec_prec = sec ? 2 : 0; + char buf[sizeof "+0000" + INT_STRLEN_BOUND (long int)]; + zone_name = make_formatted_string (buf, "%c%.2ld%.*d%.*d", + (offset < 0 ? '-' : '+'), + hour, min_prec, min, sec_prec, sec); + } + } + + return list2 (zone_offset, zone_name); +} + +DEFUN ("set-time-zone-rule", Fset_time_zone_rule, Sset_time_zone_rule, 1, 1, 0, + doc: /* Set the Emacs local time zone using TZ, a string specifying a time zone rule. +If TZ is nil or `wall', use system wall clock time; this differs from +the usual Emacs convention where nil means current local time. If TZ +is t, use Universal Time. If TZ is a list (as from +`current-time-zone') or an integer (as from `decode-time'), use the +specified time zone without consideration for daylight saving time. + +Instead of calling this function, you typically want something else. +To temporarily use a different time zone rule for just one invocation +of `decode-time', `encode-time', or `format-time-string', pass the +function a ZONE argument. To change local time consistently +throughout Emacs, call (setenv "TZ" TZ): this changes both the +environment of the Emacs process and the variable +`process-environment', whereas `set-time-zone-rule' affects only the +former. */) + (Lisp_Object tz) +{ + tzlookup (NILP (tz) ? Qwall : tz, true); + return Qnil; +} + +/* A buffer holding a string of the form "TZ=value", intended + to be part of the environment. If TZ is supposed to be unset, + the buffer string is "tZ=". */ + static char *tzvalbuf; + +/* Get the local time zone rule. */ +char * +emacs_getenv_TZ (void) +{ + return tzvalbuf[0] == 'T' ? tzvalbuf + tzeqlen : 0; +} + +/* Set the local time zone rule to TZSTRING, which can be null to + denote wall clock time. Do not record the setting in LOCAL_TZ. + + This function is not thread-safe, in theory because putenv is not, + but mostly because of the static storage it updates. Other threads + that invoke localtime etc. may be adversely affected while this + function is executing. */ + +int +emacs_setenv_TZ (const char *tzstring) +{ + static ptrdiff_t tzvalbufsize; + ptrdiff_t tzstringlen = tzstring ? strlen (tzstring) : 0; + char *tzval = tzvalbuf; + bool new_tzvalbuf = tzvalbufsize <= tzeqlen + tzstringlen; + + if (new_tzvalbuf) + { + /* Do not attempt to free the old tzvalbuf, since another thread + may be using it. In practice, the first allocation is large + enough and memory does not leak. */ + tzval = xpalloc (NULL, &tzvalbufsize, + tzeqlen + tzstringlen - tzvalbufsize + 1, -1, 1); + tzvalbuf = tzval; + tzval[1] = 'Z'; + tzval[2] = '='; + } + + if (tzstring) + { + /* Modify TZVAL in place. Although this is dicey in a + multithreaded environment, we know of no portable alternative. + Calling putenv or setenv could crash some other thread. */ + tzval[0] = 'T'; + strcpy (tzval + tzeqlen, tzstring); + } + else + { + /* Turn 'TZ=whatever' into an empty environment variable 'tZ='. + Although this is also dicey, calling unsetenv here can crash Emacs. + See Bug#8705. */ + tzval[0] = 't'; + tzval[tzeqlen] = 0; + } + + +#ifndef WINDOWSNT + /* Modifying *TZVAL merely requires calling tzset (which is the + caller's responsibility). However, modifying TZVAL requires + calling putenv; although this is not thread-safe, in practice this + runs only on startup when there is only one thread. */ + bool need_putenv = new_tzvalbuf; +#else + /* MS-Windows 'putenv' copies the argument string into a block it + allocates, so modifying *TZVAL will not change the environment. + However, the other threads run by Emacs on MS-Windows never call + 'xputenv' or 'putenv' or 'unsetenv', so the original cause for the + dicey in-place modification technique doesn't exist there in the + first place. */ + bool need_putenv = true; +#endif + if (need_putenv) + xputenv (tzval); + + return 0; +} + +void +syms_of_timefns (void) +{ +#ifndef timespec_hz + timespec_hz = make_int (TIMESPEC_HZ); + staticpro (×pec_hz); +#endif +#ifndef trillion + trillion = make_int (1000000000000); + staticpro (&trillion); +#endif +#if (ULONG_MAX < TRILLION || !FASTER_TIMEFNS) && !defined ztrillion + mpz_init_set_ui (ztrillion, 1000000); + mpz_mul_ui (ztrillion, ztrillion, 1000000); +#endif + + DEFSYM (Qencode_time, "encode-time"); + + defsubr (&Scurrent_time); + defsubr (&Stime_add); + defsubr (&Stime_subtract); + defsubr (&Stime_less_p); + defsubr (&Stime_equal_p); + defsubr (&Sformat_time_string); + defsubr (&Sfloat_time); + defsubr (&Sdecode_time); + defsubr (&Sencode_time); + defsubr (&Scurrent_time_string); + defsubr (&Scurrent_time_zone); + defsubr (&Sset_time_zone_rule); +} |