chromium/third_party/blink/renderer/platform/wtf/date_math.h

/*
 * Copyright (C) 1999-2000 Harri Porten ([email protected])
 * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
 * Copyright (C) 2009 Google Inc. All rights reserved.
 * Copyright (C) 2010 Research In Motion Limited. All rights reserved.
 *
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Communicator client code, released
 * March 31, 1998.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 */

#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_DATE_MATH_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_DATE_MATH_H_

#include <stdint.h>
#include <string.h>

#include <optional>

#include "base/time/time.h"
#include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
#include "third_party/blink/renderer/platform/wtf/wtf_export.h"

namespace WTF {

// Not really math related, but this is currently the only shared place to put
// these.
//
// TODO(tkent): Only blink::ParseDate() uses this function to parse HTTP
// header values. net::HTTPResponseHeaders::GetTimeValuedHeader() uses
// base::Time::FromUTCString() for the same purpose.  We should consider
// switching to base::Time::FromUTCString() for consistency.
WTF_EXPORT std::optional<base::Time> ParseDateFromNullTerminatedCharacters(
    const char* date_string);

const double kMinutesPerHour = …;
const double kSecondsPerMinute = …;
const double kMsPerSecond = …;
const double kMsPerMinute = …;
const double kMsPerHour = …;
const double kMsPerDay = …;

WTF_EXPORT bool IsLeapYear(int year);

// Returns the number of days from 1970-01-01 to the specified date.
WTF_EXPORT double DateToDaysFrom1970(int year, int month, int day);
WTF_EXPORT int MsToYear(double ms);
WTF_EXPORT int DayInYear(int year, int month, int day);
WTF_EXPORT int DayInYear(double ms, int year);
WTF_EXPORT int MonthFromDayInYear(int day_in_year, bool leap_year);
WTF_EXPORT int DayInMonthFromDayInYear(int day_in_year, bool leap_year);

// Returns a TimeDelta between the UNIX epoch in the local timezone and the
// specified time.
//
// For example, if the local timezone is PDT and the specified time represents
// "2019-08-09 13:00 PDT", this function returns a TimeDelta since
// "1970-01-01 00:00 PDT".
WTF_EXPORT base::TimeDelta ConvertToLocalTime(base::Time time);

}  // namespace WTF

IsLeapYear;
DateToDaysFrom1970;
DayInMonthFromDayInYear;
DayInYear;
kMinutesPerHour;
MonthFromDayInYear;
kMsPerDay;
kMsPerHour;
kMsPerMinute;
kMsPerSecond;
MsToYear;
kSecondsPerMinute;
ParseDateFromNullTerminatedCharacters;
ConvertToLocalTime;

#endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_DATE_MATH_H_