| /* |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code 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 |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * Copyright (c) 2009-2012, Stephen Colebourne & Michael Nascimento Santos |
| * |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are met: |
| * |
| * * Redistributions of source code must retain the above copyright notice, |
| * this list of conditions and the following disclaimer. |
| * |
| * * Redistributions in binary form must reproduce the above copyright notice, |
| * this list of conditions and the following disclaimer in the documentation |
| * and/or other materials provided with the distribution. |
| * |
| * * Neither the name of JSR-310 nor the names of its contributors |
| * may be used to endorse or promote products derived from this software |
| * without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
| * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| package build.tools.tzdb; |
| |
| import java.util.Objects; |
| |
| class Utils { |
| |
| // Returns the largest (closest to positive infinity) |
| public static long floorDiv(long x, long y) { |
| long r = x / y; |
| // if the signs are different and modulo not zero, round down |
| if ((x ^ y) < 0 && (r * y != x)) { |
| r--; |
| } |
| return r; |
| } |
| |
| // Returns the floor modulus of the {@code long} arguments. |
| public static long floorMod(long x, long y) { |
| return x - floorDiv(x, y) * y; |
| } |
| |
| // Returns the sum of its arguments, |
| public static long addExact(long x, long y) { |
| long r = x + y; |
| // HD 2-12 Overflow iff both arguments have the opposite sign of the result |
| if (((x ^ r) & (y ^ r)) < 0) { |
| throw new ArithmeticException("long overflow"); |
| } |
| return r; |
| } |
| |
| // Year |
| |
| // Returns true if the specified year is a leap year. |
| public static boolean isLeapYear(int year) { |
| return ((year & 3) == 0) && ((year % 100) != 0 || (year % 400) == 0); |
| } |
| |
| // The minimum supported year, '-999,999,999'. |
| public static final int YEAR_MIN_VALUE = -999_999_999; |
| |
| // The maximum supported year, '+999,999,999'. |
| public static final int YEAR_MAX_VALUE = 999_999_999; |
| |
| |
| // Gets the length of the specified month in days. |
| public static int lengthOfMonth(int month, boolean leapYear) { |
| switch (month) { |
| case 2: //FEBRUARY: |
| return (leapYear ? 29 : 28); |
| case 4: //APRIL: |
| case 6: //JUNE: |
| case 9: //SEPTEMBER: |
| case 11: //NOVEMBER: |
| return 30; |
| default: |
| return 31; |
| } |
| } |
| |
| // Gets the maximum length of the specified month in days. |
| public static int maxLengthOfMonth(int month) { |
| switch (month) { |
| case 2: //FEBRUARY: |
| return 29; |
| case 4: //APRIL: |
| case 6: //JUNE: |
| case 9: //SEPTEMBER: |
| case 11: //NOVEMBER: |
| return 30; |
| default: |
| return 31; |
| } |
| } |
| |
| // DayOfWeek |
| |
| // Returns the day-of-week that is the specified number of days after |
| // this one, from 1 to 7 for Monday to Sunday. |
| public static int plusDayOfWeek(int dow, long days) { |
| int amount = (int) (days % 7); |
| return (dow - 1 + (amount + 7)) % 7 + 1; |
| } |
| |
| // Returns the day-of-week that is the specified number of days before |
| // this one, from 1 to 7 for Monday to Sunday. |
| public static int minusDayOfWeek(int dow, long days) { |
| return plusDayOfWeek(dow, -(days % 7)); |
| } |
| |
| // Adjusts the date to the first occurrence of the specified day-of-week |
| // before the date being adjusted unless it is already on that day in |
| // which case the same object is returned. |
| public static LocalDate previousOrSame(LocalDate date, int dayOfWeek) { |
| return adjust(date, dayOfWeek, 1); |
| } |
| |
| // Adjusts the date to the first occurrence of the specified day-of-week |
| // after the date being adjusted unless it is already on that day in |
| // which case the same object is returned. |
| public static LocalDate nextOrSame(LocalDate date, int dayOfWeek) { |
| return adjust(date, dayOfWeek, 0); |
| } |
| |
| // Implementation of next, previous or current day-of-week. |
| // @param relative whether the current date is a valid answer |
| private static final LocalDate adjust(LocalDate date, int dow, int relative) { |
| int calDow = date.getDayOfWeek(); |
| if (relative < 2 && calDow == dow) { |
| return date; |
| } |
| if ((relative & 1) == 0) { |
| int daysDiff = calDow - dow; |
| return date.plusDays(daysDiff >= 0 ? 7 - daysDiff : -daysDiff); |
| } else { |
| int daysDiff = dow - calDow; |
| return date.minusDays(daysDiff >= 0 ? 7 - daysDiff : -daysDiff); |
| } |
| } |
| |
| } |