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Diffstat (limited to 'src/VBox/Runtime/r3/posix/timelocal-posix.cpp')
| -rw-r--r-- | src/VBox/Runtime/r3/posix/timelocal-posix.cpp | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/src/VBox/Runtime/r3/posix/timelocal-posix.cpp b/src/VBox/Runtime/r3/posix/timelocal-posix.cpp new file mode 100644 index 00000000..40e2fc16 --- /dev/null +++ b/src/VBox/Runtime/r3/posix/timelocal-posix.cpp @@ -0,0 +1,215 @@ +/* $Id $ */ +/** @file + * IPRT - Local Time, Posix. + */ + +/* + * Copyright (C) 2006-2023 Oracle and/or its affiliates. + * + * This file is part of VirtualBox base platform packages, as + * available from https://www.virtualbox.org. + * + * This program 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, in version 3 of the + * License. + * + * This program 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 this program; if not, see <https://www.gnu.org/licenses>. + * + * The contents of this file may alternatively be used under the terms + * of the Common Development and Distribution License Version 1.0 + * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included + * in the VirtualBox distribution, in which case the provisions of the + * CDDL are applicable instead of those of the GPL. + * + * You may elect to license modified versions of this file under the + * terms and conditions of either the GPL or the CDDL or both. + * + * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0 + */ + + +/********************************************************************************************************************************* +* Header Files * +*********************************************************************************************************************************/ +#define LOG_GROUP RTLOGGROUP_TIME +#define RTTIME_INCL_TIMEVAL +#include <iprt/types.h> +#include <iprt/assert.h> + +#include <sys/time.h> +#include <time.h> + +#include <iprt/time.h> + + +/** + * This tries to find the UTC offset for a given timespec. + * + * It does probably not take into account changes in daylight + * saving over the years or similar stuff. + * + * @returns UTC offset in nanoseconds. + * @param pTime The time. + * @param fCurrentTime Whether the input is current time or not. + * This is for avoid infinit recursion on errors in the fallback path. + */ +static int64_t rtTimeLocalUTCOffset(PCRTTIMESPEC pTime, bool fCurrentTime) +{ + RTTIMESPEC Fallback; + + /* + * Convert to time_t. + */ + int64_t i64UnixTime = RTTimeSpecGetSeconds(pTime); + time_t UnixTime = i64UnixTime; + if (UnixTime != i64UnixTime) + return fCurrentTime ? 0 : rtTimeLocalUTCOffset(RTTimeNow(&Fallback), true); + + /* + * Explode it as both local and UTC time. + */ + struct tm TmLocal; + if ( !localtime_r(&UnixTime, &TmLocal) + || !TmLocal.tm_year) + return fCurrentTime ? 0 : rtTimeLocalUTCOffset(RTTimeNow(&Fallback), true); + struct tm TmUtc; + if (!gmtime_r(&UnixTime, &TmUtc)) + return fCurrentTime ? 0 : rtTimeLocalUTCOffset(RTTimeNow(&Fallback), true); + + /* + * Calc the difference (if any). + * We ASSUME that the difference is less that 24 hours. + */ + if ( TmLocal.tm_hour == TmUtc.tm_hour + && TmLocal.tm_min == TmUtc.tm_min + && TmLocal.tm_sec == TmUtc.tm_sec + && TmLocal.tm_mday == TmUtc.tm_mday) + return 0; + + int cLocalSecs = TmLocal.tm_hour * 3600 + + TmLocal.tm_min * 60 + + TmLocal.tm_sec; + int cUtcSecs = TmUtc.tm_hour * 3600 + + TmUtc.tm_min * 60 + + TmUtc.tm_sec; + if (TmLocal.tm_mday != TmUtc.tm_mday) + { + /* + * Must add 24 hours to the value that is ahead of the other. + * + * To determine which is ahead was busted for a long long time (bugref:9078), + * so here are some examples and two different approaches. + * + * TmLocal TmUtc => Add 24:00 to => Diff + * 2007-04-02 01:00 2007-04-01 23:00 => TmLocal => +02:00 + * 2007-04-01 01:00 2007-03-31 23:00 => TmLocal => +02:00 + * 2007-03-31 01:00 2007-03-30 23:00 => TmLocal => +02:00 + * + * 2007-04-01 01:00 2007-04-02 23:00 => TmUtc => -02:00 + * 2007-03-31 23:00 2007-04-01 01:00 => TmUtc => -02:00 + * 2007-03-30 23:00 2007-03-31 01:00 => TmUtc => -02:00 + * + */ +#if 0 + /* Using day of month turned out to be a little complicated. */ + if ( ( TmLocal.tm_mday > TmUtc.tm_mday + && (TmUtc.tm_mday != 1 || TmLocal.tm_mday < 28) ) + || (TmLocal.tm_mday == 1 && TmUtc.tm_mday >= 28) ) + { + cLocalSecs += 24*60*60; + Assert( TmLocal.tm_yday - TmUtc.tm_yday == 1 + || (TmLocal.tm_yday == 0 && TmUtc.tm_yday >= 364 && TmLocal.tm_year == TmUtc.tm_year + 1)); + } + else + { + cUtcSecs += 24*60*60; + Assert( TmUtc.tm_yday - TmLocal.tm_yday == 1 + || (TmUtc.tm_yday == 0 && TmLocal.tm_yday >= 364 && TmUtc.tm_year == TmLocal.tm_year + 1)); + } +#else + /* Using day of year and year is simpler. */ + if ( ( TmLocal.tm_year == TmUtc.tm_year + && TmLocal.tm_yday > TmUtc.tm_yday) + || TmLocal.tm_year > TmUtc.tm_year) + { + cLocalSecs += 24*60*60; + Assert( TmLocal.tm_yday - TmUtc.tm_yday == 1 + || (TmLocal.tm_yday == 0 && TmUtc.tm_yday >= 364 && TmLocal.tm_year == TmUtc.tm_year + 1)); + } + else + { + cUtcSecs += 24*60*60; + Assert( TmUtc.tm_yday - TmLocal.tm_yday == 1 + || (TmUtc.tm_yday == 0 && TmLocal.tm_yday >= 364 && TmUtc.tm_year == TmLocal.tm_year + 1)); + } +#endif + } + + return (cLocalSecs - cUtcSecs) * INT64_C(1000000000); +} + + +/** + * Gets the current delta between UTC and local time. + * + * @code + * RTTIMESPEC LocalTime; + * RTTimeSpecAddNano(RTTimeNow(&LocalTime), RTTimeLocalDeltaNano()); + * @endcode + * + * @returns Returns the nanosecond delta between UTC and local time. + */ +RTDECL(int64_t) RTTimeLocalDeltaNano(void) +{ + RTTIMESPEC Time; + return rtTimeLocalUTCOffset(RTTimeNow(&Time), true /* current time, skip fallback */); +} + + +/** + * Gets the delta between UTC and local time at the given time. + * + * @code + * RTTIMESPEC LocalTime; + * RTTimeNow(&LocalTime); + * RTTimeSpecAddNano(&LocalTime, RTTimeLocalDeltaNanoFor(&LocalTime)); + * @endcode + * + * @param pTimeSpec The time spec giving the time to get the delta for. + * @returns Returns the nanosecond delta between UTC and local time. + */ +RTDECL(int64_t) RTTimeLocalDeltaNanoFor(PCRTTIMESPEC pTimeSpec) +{ + AssertPtr(pTimeSpec); + return rtTimeLocalUTCOffset(pTimeSpec, false /* current time, skip fallback */); +} + + +/** + * Explodes a time spec to the localized timezone. + * + * @returns pTime. + * @param pTime Where to store the exploded time. + * @param pTimeSpec The time spec to exploded. (UTC) + */ +RTDECL(PRTTIME) RTTimeLocalExplode(PRTTIME pTime, PCRTTIMESPEC pTimeSpec) +{ + RTTIMESPEC LocalTime = *pTimeSpec; + int64_t cNsUtcOffset = rtTimeLocalUTCOffset(&LocalTime, true /* current time, skip fallback */); + RTTimeSpecAddNano(&LocalTime, cNsUtcOffset); + pTime = RTTimeExplode(pTime, &LocalTime); + if (pTime) + { + pTime->fFlags = (pTime->fFlags & ~RTTIME_FLAGS_TYPE_MASK) | RTTIME_FLAGS_TYPE_LOCAL; + pTime->offUTC = cNsUtcOffset / RT_NS_1MIN; + } + return pTime; +} + |