/* Timestamp functions for Emacs Copyright (C) 1985-1987, 1989, 1993-2022 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 . */ #include /* Work around GCC bug 102671. */ #if 10 <= __GNUC__ # pragma GCC diagnostic ignored "-Wanalyzer-null-dereference" #endif #include "systime.h" #include "blockinput.h" #include "bignum.h" #include "coding.h" #include "lisp.h" #include "pdumper.h" #include #include #include #include #include #include #ifdef HAVE_TIMEZONE_T # include # if defined __NetBSD_Version__ && __NetBSD_Version__ < 700000000 # define HAVE_TZALLOC_BUG true # endif #endif #ifndef HAVE_TZALLOC_BUG # define HAVE_TZALLOC_BUG false #endif enum { 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 /* current-time-list defaults to t, typically generating (HI LO US PS) timestamps. To change the default to nil, generating (TICKS . HZ) timestamps, 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_val (trillion)) #else # define trillion make_fixnum (TRILLION) # if ULONG_MAX < TRILLION || !FASTER_TIMEFNS mpz_t ztrillion; # endif #endif /* True if the nonzero Lisp integer HZ divides evenly into a trillion. */ static bool trillion_factor (Lisp_Object hz) { if (FASTER_TIMEFNS) { if (FIXNUMP (hz)) return TRILLION % XFIXNUM (hz) == 0; if (!FIXNUM_OVERFLOW_P (TRILLION)) return false; } verify (TRILLION <= INTMAX_MAX); intmax_t ihz; return integer_to_intmax (hz, &ihz) && TRILLION % ihz == 0; } /* 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 AVOID 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 (BASE_EQ (zone, make_fixnum (0)) || BASE2_EQ (zone, Qt)) { zone_string = "UTC0"; new_tz = utc_tz; } else { bool plain_integer = FIXNUMP (zone); if (BASE2_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 (void) { #ifdef HAVE_UNEXEC /* 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 (will_dump_with_unexec_p ()) { xputenv (dump_tz_string); tzset (); return; } #endif char *tz = getenv ("TZ"); #ifdef HAVE_UNEXEC /* 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. */ static AVOID time_overflow (void) { error ("Specified time is not representable"); } static AVOID time_error (int err) { switch (err) { case ENOMEM: memory_full (SIZE_MAX); case EOVERFLOW: time_overflow (); default: error ("Invalid time specification"); } } static AVOID 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)); } /* When converting a double to a fraction TICKS / HZ, HZ is equal to FLT_RADIX * P where 0 <= P < FLT_RADIX_POWER_SIZE. The tiniest nonzero double uses the maximum P. */ enum { flt_radix_power_size = DBL_MANT_DIG - DBL_MIN_EXP + 1 }; /* A integer vector of size flt_radix_power_size. The Pth entry equals FLT_RADIX**P. */ static Lisp_Object flt_radix_power; /* Convert the finite number T into an Emacs time *RESULT, truncating toward minus infinity. Signal an error if unsuccessful. */ static void decode_float_time (double t, struct lisp_time *result) { Lisp_Object ticks, hz; if (t == 0) { ticks = make_fixnum (0); hz = make_fixnum (1); } else { int scale = double_integer_scale (t); /* FIXME: `double_integer_scale` often returns values that are "pessimistic" (i.e. larger than necessary), so 3.5 gets converted to (7881299347898368 . 2251799813685248) rather than (7 . 2). On 64bit systems, this should not matter very much, tho. */ eassume (scale < flt_radix_power_size); if (scale < 0) { /* T is finite but so large that HZ would be less than 1 if T's precision were represented exactly. SCALE must be nonnegative, as the (TICKS . HZ) representation requires HZ to be at least 1. So use SCALE = 0, which converts T to (T . 1), which is the exact numeric value with too-large HZ, which is typically better than signaling overflow. */ scale = 0; } /* Compute TICKS, HZ such that TICKS / HZ exactly equals T, where HZ is T's frequency or 1, whichever is greater. Here, “frequency” means 1/precision. Cache HZ values in flt_radix_power. */ double scaled = scalbn (t, scale); eassert (trunc (scaled) == scaled); ticks = double_to_integer (scaled); hz = AREF (flt_radix_power, scale); if (NILP (hz)) { mpz_ui_pow_ui (mpz[0], FLT_RADIX, scale); hz = make_integer_mpz (); ASET (flt_radix_power, scale, hz); } } result->ticks = ticks; result->hz = 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[0] = floor ((ticks * trillion) / hz). */ mpz_t const *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)); /* mpz[0] = floor (mpz[0] / trillion), with US = the high six digits of the 12-digit remainder, and PS = the low six digits. */ #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 /* mpz[0] = floor (mpz[0] / 1 << LO_TIME_BITS), with lo = remainder. */ 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[0] = sec * TIMESPEC_HZ + nsec. */ 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) { /* For speed, use intmax_t arithmetic if it will do. */ 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); /* Fall back on bignum arithmetic. */ 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 lisp_time_hz_ticks (struct lisp_time t, Lisp_Object hz) { /* The idea is to return the floor of ((T.ticks * HZ) / T.hz). */ /* For speed, just return T.ticks if T.hz == HZ. */ if (FASTER_TIMEFNS && BASE_EQ (t.hz, hz)) return t.ticks; /* Check HZ for validity. */ if (FIXNUMP (hz)) { if (XFIXNUM (hz) <= 0) invalid_hz (hz); /* For speed, use intmax_t arithmetic if it will do. */ 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_val (hz)))) invalid_hz (hz); /* Fall back on bignum arithmetic. */ 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) { /* The idea is to return the floor of T.ticks / T.hz. */ if (!FASTER_TIMEFNS) return lisp_time_hz_ticks (t, make_fixnum (1)); /* For speed, use EMACS_INT arithmetic if it will do. */ if (FIXNUMP (t.ticks) && FIXNUMP (t.hz)) return make_fixnum (XFIXNUM (t.ticks) / XFIXNUM (t.hz) - (XFIXNUM (t.ticks) % XFIXNUM (t.hz) < 0)); /* For speed, inline what lisp_time_hz_ticks would do. */ 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 timespec_to_lisp (t); } /* Return (TICKS . HZ) for time T. */ Lisp_Object timespec_to_lisp (struct timespec t) { return Fcons (timespec_ticks (t), timespec_hz); } /* Return NUMERATOR / DENOMINATOR, rounded to the nearest double. Arguments must be Lisp integers, and DENOMINATOR must be positive. */ static double frac_to_double (Lisp_Object numerator, Lisp_Object denominator) { intmax_t intmax_numerator, intmax_denominator; if (FASTER_TIMEFNS && integer_to_intmax (numerator, &intmax_numerator) && integer_to_intmax (denominator, &intmax_denominator) && intmax_numerator % intmax_denominator == 0) return intmax_numerator / intmax_denominator; /* Compute number of base-FLT_RADIX digits in numerator and denominator. */ mpz_t const *n = bignum_integer (&mpz[0], numerator); mpz_t const *d = bignum_integer (&mpz[1], denominator); ptrdiff_t ndig = mpz_sizeinbase (*n, FLT_RADIX); ptrdiff_t ddig = mpz_sizeinbase (*d, FLT_RADIX); /* Scale with SCALE when doing integer division. That is, compute (N * FLT_RADIX**SCALE) / D [or, if SCALE is negative, N / (D * FLT_RADIX**-SCALE)] as a bignum, convert the bignum to double, then divide the double by FLT_RADIX**SCALE. First scale N (or scale D, if SCALE is negative) ... */ ptrdiff_t scale = ddig - ndig + DBL_MANT_DIG; if (scale < 0) { mpz_mul_2exp (mpz[1], *d, - (scale * LOG2_FLT_RADIX)); d = &mpz[1]; } else { /* min so we don't scale tiny numbers as if they were normalized. */ scale = min (scale, flt_radix_power_size - 1); mpz_mul_2exp (mpz[0], *n, scale * LOG2_FLT_RADIX); n = &mpz[0]; } /* ... and then divide, with quotient Q and remainder R. */ mpz_t *q = &mpz[2]; mpz_t *r = &mpz[3]; mpz_tdiv_qr (*q, *r, *n, *d); /* The amount to add to the absolute value of Q so that truncating it to double will round correctly. */ int incr; /* Round the quotient before converting it to double. If the quotient is less than FLT_RADIX ** DBL_MANT_DIG, round to the nearest integer; otherwise, it is less than FLT_RADIX ** (DBL_MANT_DIG + 1) and round it to the nearest multiple of FLT_RADIX. Break ties to even. */ if (mpz_sizeinbase (*q, FLT_RADIX) <= DBL_MANT_DIG) { /* Converting to double will use the whole quotient so add 1 to its absolute value as per round-to-even; i.e., if the doubled remainder exceeds the denominator, or exactly equals the denominator and adding 1 would make the quotient even. */ mpz_mul_2exp (*r, *r, 1); int cmp = mpz_cmpabs (*r, *d); incr = cmp > 0 || (cmp == 0 && (FASTER_TIMEFNS && FLT_RADIX == 2 ? mpz_odd_p (*q) : mpz_tdiv_ui (*q, FLT_RADIX) & 1)); } else { /* Converting to double will discard the quotient's low-order digit, so add FLT_RADIX to its absolute value as per round-to-even. */ int lo_2digits = mpz_tdiv_ui (*q, FLT_RADIX * FLT_RADIX); eassume (0 <= lo_2digits && lo_2digits < FLT_RADIX * FLT_RADIX); int lo_digit = lo_2digits % FLT_RADIX; incr = ((lo_digit > FLT_RADIX / 2 || (lo_digit == FLT_RADIX / 2 && FLT_RADIX % 2 == 0 && ((lo_2digits / FLT_RADIX) & 1 || mpz_sgn (*r) != 0))) ? FLT_RADIX : 0); } /* Increment the absolute value of the quotient by INCR. */ if (!FASTER_TIMEFNS || incr != 0) (mpz_sgn (*n) < 0 ? mpz_sub_ui : mpz_add_ui) (*q, *q, incr); /* Rescale the integer Q back to double. This step does not round. */ return scalbn (mpz_get_d (*q), -scale); } /* From 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. Return zero, which indicates success. */ static int decode_ticks_hz (Lisp_Object ticks, Lisp_Object hz, struct lisp_time *result, double *dresult) { if (result) { result->ticks = ticks; result->hz = hz; } else *dresult = frac_to_double (ticks, hz); 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 non-float 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: if (INTEGERP (high) && !NILP (Fnatnump (low)) && !BASE_EQ (low, make_fixnum (0))) return decode_ticks_hz (high, low, result, dresult); return EINVAL; case TIMEFORM_FLOAT: eassume (false); case TIMEFORM_NIL: return decode_ticks_hz (timespec_ticks (current_timespec ()), timespec_hz, result, dresult); 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_t *s = &mpz[1]; mpz_set_intmax (*s, us / 1000000 - (us % 1000000 < 0)); mpz_add (*s, *s, *bignum_integer (&mpz[0], low)); mpz_addmul_ui (*s, *bignum_integer (&mpz[0], high), 1 << LO_TIME_BITS); ps = ps % 1000000 + 1000000 * (ps % 1000000 < 0); us = us % 1000000 + 1000000 * (us % 1000000 < 0); Lisp_Object hz; switch (form) { case TIMEFORM_HI_LO: /* Floats and nil were handled above, so it was an integer. */ mpz_swap (mpz[0], *s); hz = make_fixnum (1); break; case TIMEFORM_HI_LO_US: mpz_set_ui (mpz[0], us); mpz_addmul_ui (mpz[0], *s, 1000000); hz = make_fixnum (1000000); break; case TIMEFORM_HI_LO_US_PS: { #if FASTER_TIMEFNS && TRILLION <= ULONG_MAX unsigned long i = us; mpz_set_ui (mpz[0], i * 1000000 + ps); mpz_addmul_ui (mpz[0], *s, TRILLION); #else intmax_t i = us; mpz_set_intmax (mpz[0], i * 1000000 + ps); mpz_addmul (mpz[0], *s, ztrillion); #endif hz = trillion; } break; default: eassume (false); } return decode_ticks_hz (make_integer_mpz (), hz, result, dresult); } /* Decode a Lisp timestamp SPECIFIED_TIME that represents a time. If DECODE_SECS_ONLY, ignore and do not validate any sub-second components of an old-format 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. Return the form of SPECIFIED-TIME. Signal an error if unsuccessful. */ static enum timeform decode_lisp_time (Lisp_Object specified_time, bool decode_secs_only, 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 (CONSP (specified_time)) { high = XCAR (specified_time); low = XCDR (specified_time); if (CONSP (low)) { Lisp_Object low_tail = XCDR (low); low = XCAR (low); if (! 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 { form = TIMEFORM_TICKS_HZ; } /* Require LOW to be an integer, as otherwise the computation would be considerably trickier. */ if (! INTEGERP (low)) form = TIMEFORM_INVALID; } else if (FASTER_TIMEFNS && INTEGERP (specified_time)) { decode_ticks_hz (specified_time, make_fixnum (1), result, dresult); return form; } else if (FLOATP (specified_time)) { double d = XFLOAT_DATA (specified_time); if (!isfinite (d)) time_error (isnan (d) ? EDOM : EOVERFLOW); if (result) decode_float_time (d, result); else *dresult = d; return TIMEFORM_FLOAT; } int err = decode_time_components (form, high, low, usec, psec, result, dresult); if (err) time_error (err); return form; } /* Convert a non-float Lisp timestamp SPECIFIED_TIME to double. Signal an error if unsuccessful. */ double float_time (Lisp_Object specified_time) { double t; decode_lisp_time (specified_time, false, 0, &t); return t; } /* 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]; mpz_t const *qt = q; /* Floor-divide (T.ticks * TIMESPEC_HZ) by T.hz, yielding quotient Q (tv_sec) and remainder NS (tv_nsec). Return an invalid timespec if Q does not fit in time_t. For speed, prefer fixnum arithmetic if it works. */ if (FASTER_TIMEFNS && BASE_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_val (t.ticks), TIMESPEC_HZ); } else if (FASTER_TIMEFNS && BASE_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 qt = xbignum_val (t.ticks); } 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); } /* Check that Q fits in time_t, not merely in T.tv_sec. 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 (*qt, &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. If PFORM, store the time's form into *PFORM. */ static struct lisp_time lisp_time_struct (Lisp_Object specified_time, enum timeform *pform) { struct lisp_time t; enum timeform form = decode_lisp_time (specified_time, false, &t, 0); if (pform) *pform = form; 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) { struct lisp_time lt; decode_lisp_time (specified_time, true, <, 0); struct timespec t = lisp_to_timespec (lt); if (! timespec_valid_p (t)) time_overflow (); return t.tv_sec; } /* Return the sum of the Lisp integers A and B. Subtract instead of adding if SUBTRACT. This function is tuned for small B. */ static Lisp_Object lispint_arith (Lisp_Object a, Lisp_Object b, bool subtract) { bool mpz_done = false; if (FASTER_TIMEFNS && FIXNUMP (b)) { if (BASE_EQ (b, make_fixnum (0))) return a; /* For speed, use EMACS_INT arithmetic if it will do. */ if (FIXNUMP (a)) return make_int (subtract ? XFIXNUM (a) - XFIXNUM (b) : XFIXNUM (a) + XFIXNUM (b)); /* For speed, use mpz_add_ui/mpz_sub_ui if it will do. */ if (eabs (XFIXNUM (b)) <= ULONG_MAX) { ((XFIXNUM (b) < 0) == subtract ? mpz_add_ui : mpz_sub_ui) (mpz[0], *xbignum_val (a), eabs (XFIXNUM (b))); mpz_done = true; } } /* Fall back on bignum arithmetic if necessary. */ if (!mpz_done) (subtract ? mpz_sub : mpz_add) (mpz[0], *bignum_integer (&mpz[0], a), *bignum_integer (&mpz[1], b)); return make_integer_mpz (); } /* Given Lisp operands A and B, add their values, and return the result as a Lisp timestamp. Subtract instead of adding if SUBTRACT. */ static Lisp_Object time_arith (Lisp_Object a, Lisp_Object b, bool subtract) { 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 && BASE_EQ (ta.hz, tb.hz)) { hz = ta.hz; ticks = lispint_arith (ta.ticks, tb.ticks, subtract); } else { /* The plan is to decompose ta into na/da and tb into nb/db. Start by computing da and db, their minimum (which will be needed later) and the iticks temporary that will become available once only their minimum is needed. */ mpz_t const *da = bignum_integer (&mpz[1], ta.hz); mpz_t const *db = bignum_integer (&mpz[2], tb.hz); bool da_lt_db = mpz_cmp (*da, *db) < 0; mpz_t const *hzmin = da_lt_db ? da : db; mpz_t *iticks = &mpz[da_lt_db + 1]; /* 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[4], *fb = &mpz[3]; mpz_divexact (*fa, *da, *g); mpz_divexact (*fb, *db, *g); /* ihz = fa * db. This is equal to lcm (da, db). */ mpz_t *ihz = &mpz[0]; mpz_mul (*ihz, *fa, *db); /* iticks = (fb * na) OP (fa * nb), where OP is + or -. */ mpz_t const *na = bignum_integer (iticks, ta.ticks); mpz_mul (*iticks, *fb, *na); mpz_t const *nb = bignum_integer (&mpz[3], tb.ticks); (subtract ? mpz_submul : mpz_addmul) (*iticks, *fa, *nb); /* Normalize iticks/ihz by dividing both numerator and denominator by ig = gcd (iticks, ihz). For speed, though, skip this division if ihz = 1. */ mpz_t *ig = &mpz[3]; mpz_gcd (*ig, *iticks, *ihz); if (!FASTER_TIMEFNS || mpz_cmp_ui (*ig, 1) > 0) { mpz_divexact (*iticks, *iticks, *ig); mpz_divexact (*ihz, *ihz, *ig); /* However, if dividing the denominator by ig would cause the denominator to become less than hzmin, rescale the denominator upwards by multiplying the normalized numerator and denominator so that the resulting denominator becomes at least hzmin. This rescaling avoids returning a timestamp that is less precise than both a and b. */ if (!FASTER_TIMEFNS || mpz_cmp (*ihz, *hzmin) < 0) { /* Rescale straightforwardly. Although this might not yield the minimal denominator that preserves numeric value and is at least hzmin, calculating such a denominator would be too expensive because it would require testing multisets of factors of lcm (da, db). */ mpz_t *rescale = &mpz[3]; mpz_cdiv_q (*rescale, *hzmin, *ihz); mpz_mul (*iticks, *iticks, *rescale); mpz_mul (*ihz, *ihz, *rescale); } } /* mpz[0] and iticks now correspond to the (HZ . TICKS) pair. */ hz = make_integer_mpz (); mpz_swap (mpz[0], *iticks); ticks = make_integer_mpz (); } /* Return an integer if the timestamp resolution is 1, otherwise the (TICKS . HZ) form if !current_time_list or if either input used (TICKS . HZ) form or the result can't be expressed exactly in (HI LO US PS) form, otherwise the (HI LO US PS) form for backward compatibility. */ return (BASE_EQ (hz, make_fixnum (1)) ? ticks : (!current_time_list || aform == TIMEFORM_TICKS_HZ || bform == TIMEFORM_TICKS_HZ || !trillion_factor (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) { /* Subtract nil from nil correctly, and handle other eq values quicker while we're at it. This means (time-subtract X X) does not signal an error if X is not a valid time value, but that's OK. */ if (BASE_EQ (a, b)) return timespec_to_lisp ((struct timespec) {0}); return time_arith (a, b, true); } /* Return negative, 0, positive if A < B, A == B, A > B respectively. A and B should be Lisp time values. */ static EMACS_INT time_cmp (Lisp_Object a, Lisp_Object b) { /* Compare nil to nil correctly, and handle other eq values quicker while we're at it. This means (time-equal-p X X) does not signal an error if X is not a valid time value, but that's OK. */ if (BASE_EQ (a, b)) return 0; /* Compare (X . Z) to (Y . Z) quickly if X and Y are fixnums. Do not inspect Z, as it is OK to not signal if A and B are invalid. Also, compare X to Y quickly if X and Y are fixnums. */ if (FASTER_TIMEFNS) { Lisp_Object x = a, y = b; if (CONSP (a) && CONSP (b) && BASE_EQ (XCDR (a), XCDR (b))) x = XCAR (a), y = XCAR (b); if (FIXNUMP (x) && FIXNUMP (y)) return XFIXNUM (x) - XFIXNUM (y); } /* Compare (ATICKS . AZ) to (BTICKS . BHZ) by comparing ATICKS * BHZ to BTICKS * AHZ. */ struct lisp_time ta = lisp_time_struct (a, 0); struct lisp_time tb = lisp_time_struct (b, 0); mpz_t const *za = bignum_integer (&mpz[0], ta.ticks); mpz_t const *zb = bignum_integer (&mpz[1], tb.ticks); if (! (FASTER_TIMEFNS && BASE_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) { /* A nil arg compares unequal to a non-nil arg. This also saves the expense of current_timespec if either arg is nil. */ return NILP (a) == NILP (b) && 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 `time-convert', or (if you need time as a string) `format-time-string'. */) (Lisp_Object specified_time) { return (FLOATP (specified_time) ? specified_time : make_float (float_time (specified_time))); } /* 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. */ 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) { int saved_errno = errno; 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 (;;) { errno = 0; size_t result = nstrftime (s, maxsize, format, tp, tz, ns); if (result == 0 && errno != 0) return result; if (s) s += result + 1; maxsize -= result + 1; total += result; size_t len = strlen (format); if (len == format_len) break; total++; format += len + 1; format_len -= len + 1; } errno = saved_errno; return total; } 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) { errno = 0; len = emacs_nmemftime (buf, size, format, formatlen, tmp, tz, ns); if (len != 0 || errno == 0) break; eassert (errno == ERANGE); /* 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 year without century, %C the century. %G is the year corresponding to the ISO week, %g year corresponding to the ISO week, without 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 the week number 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 "%+4Y-%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. A %-sequence can contain optional flags, field width, and a modifier (in that order) after the `%'. The flags are: `-' Do not pad the field. `_' Pad with spaces. `0' Pad with zeros. `+' Pad with zeros and put `+' before nonnegative year numbers with >4 digits. `^' Use upper case characters if possible. `#' Use opposite case characters if possible. A field width N is an unsigned decimal integer with a leading digit nonzero. %NX is like %X, but takes up at least N positions. The field width is (on GNU/Linux and some other systems) in measured in bytes, not characters. It depends on the locale what the width (in characters) %NX will end up being, especially when there are non-ASCII characters in %X. The modifiers are: `E' Use the locale's alternative version. `O' Use 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, 3, 0, doc: /* Decode a timestamp into (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 optional FORM specifies the form of the SEC member. If `integer', SEC is an integer; if t, SEC is an integer or (TICKS . HZ) timestamp with the same precision as TIME. An omitted or nil FORM is currently treated like `integer', but this may change in future Emacs versions. To access (or alter) the elements in the time value, the `decoded-time-second', `decoded-time-minute', `decoded-time-hour', `decoded-time-day', `decoded-time-month', `decoded-time-year', `decoded-time-weekday', `decoded-time-dst' and `decoded-time-zone' accessors can be used. The list has the following nine members: SEC is an integer or Lisp timestamp representing a nonnegative value less than 60 \(or less than 61 if the operating system supports leap seconds). 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 the year number, an integer; 0 represents 1 BC. 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, and its SEC is always an integer between 0 and 59.) usage: (decode-time &optional TIME ZONE FORM) */) (Lisp_Object specified_time, Lisp_Object zone, Lisp_Object form) { /* Compute broken-down local time LOCAL_TM from SPECIFIED_TIME and ZONE. */ struct lisp_time lt = lisp_time_struct (specified_time, 0); struct timespec ts = lisp_to_timespec (lt); if (! timespec_valid_p (ts)) time_overflow (); time_t time_spec = ts.tv_sec; 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); /* Let YEAR = LOCAL_TM.tm_year + TM_YEAR_BASE. */ Lisp_Object year; if (FASTER_TIMEFNS && MOST_NEGATIVE_FIXNUM - TM_YEAR_BASE <= local_tm.tm_year && local_tm.tm_year <= MOST_POSITIVE_FIXNUM - TM_YEAR_BASE) { /* Avoid overflow when INT_MAX - TM_YEAR_BASE < local_tm.tm_year. */ EMACS_INT tm_year_base = TM_YEAR_BASE; year = make_fixnum (local_tm.tm_year + tm_year_base); } else { mpz_set_si (mpz[0], local_tm.tm_year); mpz_add_ui (mpz[0], mpz[0], TM_YEAR_BASE); year = make_integer_mpz (); } /* Compute SEC from LOCAL_TM.tm_sec and HZ. */ Lisp_Object hz = lt.hz, sec; if (BASE_EQ (hz, make_fixnum (1)) || !BASE2_EQ (form, Qt)) sec = make_fixnum (local_tm.tm_sec); else { /* Let TICKS = HZ * LOCAL_TM.tm_sec + mod (LT.ticks, HZ) and SEC = (TICKS . HZ). */ Lisp_Object ticks; intmax_t n; if (FASTER_TIMEFNS && FIXNUMP (lt.ticks) && FIXNUMP (hz) && !INT_MULTIPLY_WRAPV (XFIXNUM (hz), local_tm.tm_sec, &n) && ! (INT_ADD_WRAPV (n, (XFIXNUM (lt.ticks) % XFIXNUM (hz) + (XFIXNUM (lt.ticks) % XFIXNUM (hz) < 0 ? XFIXNUM (hz) : 0)), &n))) ticks = make_int (n); else { mpz_fdiv_r (mpz[0], *bignum_integer (&mpz[0], lt.ticks), *bignum_integer (&mpz[1], hz)); mpz_addmul_ui (mpz[0], *bignum_integer (&mpz[1], hz), local_tm.tm_sec); ticks = make_integer_mpz (); } sec = Fcons (ticks, hz); } return CALLN (Flist, 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), year, 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 integer 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 TIME to a timestamp. TIME is a list (SECOND MINUTE HOUR DAY MONTH YEAR IGNORED DST ZONE) in the style of `decode-time', so that (encode-time (decode-time ...)) works. In this list, ZONE can be nil for Emacs local time, t for Universal Time, `wall' for system wall clock time, or a string as in the TZ environment variable. ZONE 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 ZONE specifies a time zone with daylight-saving transitions, DST is t for daylight saving time, nil for standard time, and -1 to cause the daylight saving flag to be guessed. TIME can also be a list (SECOND MINUTE HOUR DAY MONTH YEAR), which is equivalent to (SECOND MINUTE HOUR DAY MONTH YEAR nil -1 nil). 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. 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. In this obsolescent convention, DST is -1 and ZONE defaults to nil. The range of supported years is at least 1970 to the near future. Out-of-range values for SECOND through MONTH are brought into range via date arithmetic. This can be tricky especially when combined with DST; see Info node `(elisp)Time Conversion' for details and caveats. usage: (encode-time TIME &rest OBSOLESCENT-ARGUMENTS) */) (ptrdiff_t nargs, Lisp_Object *args) { struct tm tm; Lisp_Object zone = Qnil; Lisp_Object a = args[0]; Lisp_Object secarg, minarg, hourarg, mdayarg, monarg, yeararg; tm.tm_isdst = -1; if (nargs == 1) { Lisp_Object tail = a; for (int i = 0; i < 6; i++, tail = XCDR (tail)) CHECK_CONS (tail); secarg = XCAR (a); a = XCDR (a); minarg = XCAR (a); a = XCDR (a); hourarg = XCAR (a); a = XCDR (a); mdayarg = XCAR (a); a = XCDR (a); monarg = XCAR (a); a = XCDR (a); yeararg = XCAR (a); a = XCDR (a); if (! NILP (a)) { CHECK_CONS (a); a = XCDR (a); CHECK_CONS (a); Lisp_Object dstflag = XCAR (a); a = XCDR (a); CHECK_CONS (a); zone = XCAR (a); if (SYMBOLP (dstflag) && !FIXNUMP (zone) && !CONSP (zone)) tm.tm_isdst = !NILP (dstflag); } } else if (nargs < 6) xsignal2 (Qwrong_number_of_arguments, Qencode_time, make_fixnum (nargs)); else { if (6 < nargs) zone = args[nargs - 1]; secarg = a; minarg = args[1]; hourarg = args[2]; mdayarg = args[3]; monarg = args[4]; yeararg = args[5]; } /* Let SEC = floor (LT.ticks / HZ), with SUBSECTICKS the remainder. */ struct lisp_time lt; decode_lisp_time (secarg, false, <, 0); Lisp_Object hz = lt.hz, sec, subsecticks; if (FASTER_TIMEFNS && BASE_EQ (hz, make_fixnum (1))) { sec = lt.ticks; subsecticks = make_fixnum (0); } else { mpz_fdiv_qr (mpz[0], mpz[1], *bignum_integer (&mpz[0], lt.ticks), *bignum_integer (&mpz[1], hz)); sec = make_integer_mpz (); mpz_swap (mpz[0], mpz[1]); subsecticks = make_integer_mpz (); } tm.tm_sec = check_tm_member (sec, 0); tm.tm_min = check_tm_member (minarg, 0); tm.tm_hour = check_tm_member (hourarg, 0); tm.tm_mday = check_tm_member (mdayarg, 0); tm.tm_mon = check_tm_member (monarg, 1); tm.tm_year = check_tm_member (yeararg, 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); if (BASE_EQ (hz, make_fixnum (1))) return (current_time_list ? list2 (hi_time (value), lo_time (value)) : INT_TO_INTEGER (value)); else { struct lisp_time val1 = { INT_TO_INTEGER (value), make_fixnum (1) }; Lisp_Object secticks = lisp_time_hz_ticks (val1, hz); Lisp_Object ticks = lispint_arith (secticks, subsecticks, false); return Fcons (ticks, hz); } } DEFUN ("time-convert", Ftime_convert, Stime_convert, 1, 2, 0, doc: /* Convert TIME value to a Lisp timestamp of the given FORM. Truncate the returned value toward minus infinity. If FORM is a positive integer, return a pair of integers (TICKS . FORM), where TICKS is the number of clock ticks and FORM is the clock frequency in ticks per second. If FORM is t, return (TICKS . PHZ), where PHZ is a suitable clock frequency in ticks per second. If FORM is `integer', return an integer count of seconds. If FORM is `list', return 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. If FORM is nil, the behavior depends on `current-time-list', but new code should not rely on it. */) (Lisp_Object time, Lisp_Object form) { /* FIXME: Any reason why we don't offer a `float` output format option as well, since we accept it as input? */ struct lisp_time t; enum timeform input_form = decode_lisp_time (time, false, &t, 0); if (NILP (form)) form = current_time_list ? Qlist : Qt; if (symbols_with_pos_enabled && SYMBOL_WITH_POS_P (form)) form = SYMBOL_WITH_POS_SYM (form); if (BASE_EQ (form, Qlist)) return ticks_hz_list4 (t.ticks, t.hz); if (BASE_EQ (form, Qinteger)) return FASTER_TIMEFNS && INTEGERP (time) ? time : lisp_time_seconds (t); if (BASE_EQ (form, Qt)) form = t.hz; if (FASTER_TIMEFNS && input_form == TIMEFORM_TICKS_HZ && BASE_EQ (form, XCDR (time))) return time; return Fcons (lisp_time_hz_ticks (t, form), 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. If the variable `current-time-list' is nil, the time is returned as a pair of integers (TICKS . HZ), where TICKS counts clock ticks and HZ is the clock ticks per second. Otherwise, the time is returned as a list of integers (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. You can use `time-convert' to get a particular timestamp form regardless of the value of `current-time-list'. */) (void) { return make_lisp_time (current_timespec ()); } #ifdef CLOCKS_PER_SEC DEFUN ("current-cpu-time", Fcurrent_cpu_time, Scurrent_cpu_time, 0, 0, 0, doc: /* Return the current CPU time along with its resolution. The return value is a pair (CPU-TICKS . TICKS-PER-SEC). The CPU-TICKS counter can wrap around, so values cannot be meaningfully compared if too much time has passed between them. */) (void) { return Fcons (make_int (clock ()), make_int (CLOCKS_PER_SEC)); } #endif 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" }; intmax_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 %"PRIdMAX, 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; } #if (ULONG_MAX < TRILLION || !FASTER_TIMEFNS) && !defined ztrillion # define NEED_ZTRILLION_INIT 1 #endif #ifdef NEED_ZTRILLION_INIT static void syms_of_timefns_for_pdumper (void) { mpz_init_set_ui (ztrillion, 1000000); mpz_mul_ui (ztrillion, ztrillion, 1000000); } #endif 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 DEFSYM (Qencode_time, "encode-time"); DEFVAR_BOOL ("current-time-list", current_time_list, doc: /* Whether `current-time' should return list or (TICKS . HZ) form. This boolean variable is a transition aid. If t, `current-time' and related functions return timestamps in list form, typically \(HIGH LOW USEC PSEC); otherwise, they use (TICKS . HZ) form. Currently this variable defaults to t, for behavior compatible with previous Emacs versions. Developers are encouraged to test timestamp-related code with this variable set to nil, as it will default to nil in a future Emacs version, and will be removed in some version after that. */); current_time_list = CURRENT_TIME_LIST; defsubr (&Scurrent_time); #ifdef CLOCKS_PER_SEC defsubr (&Scurrent_cpu_time); #endif defsubr (&Stime_convert); 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); flt_radix_power = make_nil_vector (flt_radix_power_size); staticpro (&flt_radix_power); #ifdef NEED_ZTRILLION_INIT pdumper_do_now_and_after_load (syms_of_timefns_for_pdumper); #endif }