--- /dev/null 2013-01-18 16:17:08.886776012 -0800 +++ new/make/tools/src/build/tools/tzdb/Utils.java 2013-01-22 16:57:30.000000000 -0800 @@ -0,0 +1,176 @@ +/* + * 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); + } + } + +}