From 083d2708f9ec7f09712488a99fc9eedd3d594ff6 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Thu, 28 Apr 2022 12:50:39 -0700 Subject: Change current-time back to list form Change current-time and related functions back to using the traditional list form. Also, add a new boolean variable current-time-list that lets people try out (TICKS . HZ) form, with the goal of smoothing the transition. * src/timefns.c (CURRENT_TIME_LIST): Change default back to true. (current-time-list): New boolean Lisp variable, which defaults to CURRENT_TIME_LIST. All uses of CURRENT_TIME_LIST changed to use current_time_list, and all documentation changed. --- src/timefns.c | 48 +++++++++++++++++++++++++++++++----------------- 1 file changed, 31 insertions(+), 17 deletions(-) (limited to 'src/timefns.c') diff --git a/src/timefns.c b/src/timefns.c index 651e0760e83..bca9a566e08 100644 --- a/src/timefns.c +++ b/src/timefns.c @@ -69,11 +69,11 @@ enum { TM_YEAR_BASE = 1900 }; # define FASTER_TIMEFNS 1 #endif -/* current-time etc. generate (TICKS . HZ) timestamps. - To change that to the old 4-element list format (HI LO US PS), - compile with -DCURRENT_TIME_LIST=1. */ +/* 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 = false }; +enum { CURRENT_TIME_LIST = true }; #endif #if FIXNUM_OVERFLOW_P (1000000000) @@ -568,7 +568,7 @@ lisp_time_seconds (struct lisp_time t) Lisp_Object make_lisp_time (struct timespec t) { - if (CURRENT_TIME_LIST) + if (current_time_list) { time_t s = t.tv_sec; int ns = t.tv_nsec; @@ -1171,13 +1171,13 @@ time_arith (Lisp_Object a, Lisp_Object b, bool subtract) } /* Return an integer if the timestamp resolution is 1, - otherwise the (TICKS . HZ) form if !CURRENT_TIME_LIST or if + 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 (EQ (hz, make_fixnum (1)) ? ticks - : (!CURRENT_TIME_LIST + : (!current_time_list || aform == TIMEFORM_TICKS_HZ || bform == TIMEFORM_TICKS_HZ || !trillion_factor (hz)) @@ -1716,7 +1716,7 @@ usage: (encode-time TIME &rest OBSOLESCENT-ARGUMENTS) */) time_error (mktime_errno); if (EQ (hz, make_fixnum (1))) - return (CURRENT_TIME_LIST + return (current_time_list ? list2 (hi_time (value), lo_time (value)) : INT_TO_INTEGER (value)); else @@ -1747,7 +1747,7 @@ bits, and USEC and PSEC are the microsecond and picosecond counts. */) struct lisp_time t; enum timeform input_form = decode_lisp_time (time, false, &t, 0); if (NILP (form)) - form = CURRENT_TIME_LIST ? Qlist : Qt; + form = current_time_list ? Qlist : Qt; if (EQ (form, Qlist)) return ticks_hz_list4 (t.ticks, t.hz); if (EQ (form, Qinteger)) @@ -1762,14 +1762,15 @@ bits, and USEC and PSEC are the microsecond and picosecond counts. */) 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 pair of integers (TICKS . HZ), where TICKS -counts clock ticks and HZ is the clock ticks per second. - -In Emacs 28 and earlier, the returned timestamp had the form (HIGH LOW -USEC PSEC), where HIGH is the most significant bits of the seconds, -LOW the least significant 16 bits, and USEC and PSEC are the -microsecond and picosecond counts. Use \(time-convert nil \\='list) -if you need this older timestamp form. */) +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 ()); @@ -2025,6 +2026,19 @@ syms_of_timefns (void) 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 encourage 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); -- cgit v1.2.1