mirror of git://gcc.gnu.org/git/gcc.git
848 lines
24 KiB
Java
848 lines
24 KiB
Java
/* Long.java -- object wrapper for long
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Copyright (C) 1998, 1999, 2001, 2002, 2004, 2005 Free Software Foundation, Inc.
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This file is part of GNU Classpath.
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GNU Classpath is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU Classpath is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU Classpath; see the file COPYING. If not, write to the
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Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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02110-1301 USA.
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Linking this library statically or dynamically with other modules is
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making a combined work based on this library. Thus, the terms and
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conditions of the GNU General Public License cover the whole
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combination.
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As a special exception, the copyright holders of this library give you
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permission to link this library with independent modules to produce an
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executable, regardless of the license terms of these independent
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modules, and to copy and distribute the resulting executable under
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terms of your choice, provided that you also meet, for each linked
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independent module, the terms and conditions of the license of that
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module. An independent module is a module which is not derived from
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or based on this library. If you modify this library, you may extend
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this exception to your version of the library, but you are not
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obligated to do so. If you do not wish to do so, delete this
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exception statement from your version. */
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package java.lang;
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/**
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* Instances of class <code>Long</code> represent primitive
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* <code>long</code> values.
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*
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* Additionally, this class provides various helper functions and variables
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* related to longs.
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*
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* @author Paul Fisher
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* @author John Keiser
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* @author Warren Levy
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* @author Eric Blake (ebb9@email.byu.edu)
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* @author Tom Tromey (tromey@redhat.com)
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* @author Andrew John Hughes (gnu_andrew@member.fsf.org)
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* @author Ian Rogers
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* @since 1.0
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* @status updated to 1.5
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*/
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public final class Long extends Number implements Comparable<Long>
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{
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/**
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* Compatible with JDK 1.0.2+.
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*/
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private static final long serialVersionUID = 4290774380558885855L;
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/**
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* The minimum value a <code>long</code> can represent is
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* -9223372036854775808L (or -2<sup>63</sup>).
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*/
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public static final long MIN_VALUE = 0x8000000000000000L;
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/**
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* The maximum value a <code>long</code> can represent is
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* 9223372036854775807 (or 2<sup>63</sup> - 1).
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*/
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public static final long MAX_VALUE = 0x7fffffffffffffffL;
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/**
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* The primitive type <code>long</code> is represented by this
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* <code>Class</code> object.
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* @since 1.1
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*/
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public static final Class<Long> TYPE = (Class<Long>) VMClassLoader.getPrimitiveClass ('J');
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/**
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* The number of bits needed to represent a <code>long</code>.
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* @since 1.5
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*/
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public static final int SIZE = 64;
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// This caches some Long values, and is used by boxing
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// conversions via valueOf(). We cache at least -128..127;
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// these constants control how much we actually cache.
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private static final int MIN_CACHE = -128;
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private static final int MAX_CACHE = 127;
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private static final Long[] longCache = new Long[MAX_CACHE - MIN_CACHE + 1];
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static
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{
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for (int i=MIN_CACHE; i <= MAX_CACHE; i++)
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longCache[i - MIN_CACHE] = new Long(i);
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}
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/**
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* The immutable value of this Long.
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*
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* @serial the wrapped long
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*/
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private final long value;
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/**
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* Create a <code>Long</code> object representing the value of the
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* <code>long</code> argument.
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*
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* @param value the value to use
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*/
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public Long(long value)
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{
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this.value = value;
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}
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/**
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* Create a <code>Long</code> object representing the value of the
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* argument after conversion to a <code>long</code>.
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*
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* @param s the string to convert
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* @throws NumberFormatException if the String does not contain a long
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* @see #valueOf(String)
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*/
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public Long(String s)
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{
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value = parseLong(s, 10, false);
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}
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/**
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* Return the size of a string large enough to hold the given number
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*
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* @param num the number we want the string length for (must be positive)
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* @param radix the radix (base) that will be used for the string
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* @return a size sufficient for a string of num
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*/
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private static int stringSize(long num, int radix) {
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int exp;
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if (radix < 4)
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{
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exp = 1;
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}
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else if (radix < 8)
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{
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exp = 2;
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}
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else if (radix < 16)
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{
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exp = 3;
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}
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else if (radix < 32)
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{
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exp = 4;
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}
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else
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{
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exp = 5;
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}
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int size=0;
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do
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{
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num >>>= exp;
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size++;
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}
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while(num != 0);
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return size;
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}
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/**
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* Converts the <code>long</code> to a <code>String</code> using
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* the specified radix (base). If the radix exceeds
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* <code>Character.MIN_RADIX</code> or <code>Character.MAX_RADIX</code>, 10
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* is used instead. If the result is negative, the leading character is
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* '-' ('\\u002D'). The remaining characters come from
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* <code>Character.forDigit(digit, radix)</code> ('0'-'9','a'-'z').
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*
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* @param num the <code>long</code> to convert to <code>String</code>
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* @param radix the radix (base) to use in the conversion
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* @return the <code>String</code> representation of the argument
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*/
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public static String toString(long num, int radix)
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{
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if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX)
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radix = 10;
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// Is the value negative?
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boolean isNeg = num < 0;
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// Is the string a single character?
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if (!isNeg && num < radix)
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return new String(digits, (int)num, 1, true);
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// Compute string size and allocate buffer
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// account for a leading '-' if the value is negative
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int size;
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int i;
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char[] buffer;
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if (isNeg)
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{
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num = -num;
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// When the value is MIN_VALUE, it overflows when made positive
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if (num < 0)
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{
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i = size = stringSize(MAX_VALUE, radix) + 2;
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buffer = new char[size];
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buffer[--i] = digits[(int) (-(num + radix) % radix)];
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num = -(num / radix);
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}
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else
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{
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i = size = stringSize(num, radix) + 1;
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buffer = new char[size];
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}
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}
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else
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{
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i = size = stringSize(num, radix);
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buffer = new char[size];
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}
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do
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{
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buffer[--i] = digits[(int) (num % radix)];
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num /= radix;
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}
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while (num > 0);
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if (isNeg)
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buffer[--i] = '-';
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// Package constructor avoids an array copy.
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return new String(buffer, i, size - i, true);
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}
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/**
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* Converts the <code>long</code> to a <code>String</code> assuming it is
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* unsigned in base 16.
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*
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* @param l the <code>long</code> to convert to <code>String</code>
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* @return the <code>String</code> representation of the argument
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*/
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public static String toHexString(long l)
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{
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return toUnsignedString(l, 4);
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}
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/**
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* Converts the <code>long</code> to a <code>String</code> assuming it is
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* unsigned in base 8.
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*
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* @param l the <code>long</code> to convert to <code>String</code>
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* @return the <code>String</code> representation of the argument
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*/
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public static String toOctalString(long l)
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{
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return toUnsignedString(l, 3);
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}
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/**
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* Converts the <code>long</code> to a <code>String</code> assuming it is
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* unsigned in base 2.
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*
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* @param l the <code>long</code> to convert to <code>String</code>
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* @return the <code>String</code> representation of the argument
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*/
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public static String toBinaryString(long l)
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{
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return toUnsignedString(l, 1);
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}
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/**
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* Converts the <code>long</code> to a <code>String</code> and assumes
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* a radix of 10.
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*
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* @param num the <code>long</code> to convert to <code>String</code>
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* @return the <code>String</code> representation of the argument
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* @see #toString(long, int)
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*/
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public static String toString(long num)
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{
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return toString(num, 10);
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}
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/**
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* Converts the specified <code>String</code> into an <code>int</code>
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* using the specified radix (base). The string must not be <code>null</code>
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* or empty. It may begin with an optional '-', which will negate the answer,
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* provided that there are also valid digits. Each digit is parsed as if by
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* <code>Character.digit(d, radix)</code>, and must be in the range
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* <code>0</code> to <code>radix - 1</code>. Finally, the result must be
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* within <code>MIN_VALUE</code> to <code>MAX_VALUE</code>, inclusive.
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* Unlike Double.parseDouble, you may not have a leading '+'; and 'l' or
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* 'L' as the last character is only valid in radices 22 or greater, where
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* it is a digit and not a type indicator.
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*
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* @param str the <code>String</code> to convert
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* @param radix the radix (base) to use in the conversion
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* @return the <code>String</code> argument converted to <code>long</code>
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* @throws NumberFormatException if <code>s</code> cannot be parsed as a
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* <code>long</code>
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*/
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public static long parseLong(String str, int radix)
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{
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return parseLong(str, radix, false);
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}
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/**
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* Converts the specified <code>String</code> into a <code>long</code>.
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* This function assumes a radix of 10.
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*
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* @param s the <code>String</code> to convert
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* @return the <code>int</code> value of <code>s</code>
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* @throws NumberFormatException if <code>s</code> cannot be parsed as a
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* <code>long</code>
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* @see #parseLong(String, int)
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*/
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public static long parseLong(String s)
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{
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return parseLong(s, 10, false);
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}
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/**
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* Creates a new <code>Long</code> object using the <code>String</code>
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* and specified radix (base).
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*
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* @param s the <code>String</code> to convert
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* @param radix the radix (base) to convert with
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* @return the new <code>Long</code>
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* @throws NumberFormatException if <code>s</code> cannot be parsed as a
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* <code>long</code>
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* @see #parseLong(String, int)
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*/
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public static Long valueOf(String s, int radix)
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{
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return valueOf(parseLong(s, radix, false));
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}
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/**
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* Creates a new <code>Long</code> object using the <code>String</code>,
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* assuming a radix of 10.
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*
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* @param s the <code>String</code> to convert
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* @return the new <code>Long</code>
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* @throws NumberFormatException if <code>s</code> cannot be parsed as a
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* <code>long</code>
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* @see #Long(String)
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* @see #parseLong(String)
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*/
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public static Long valueOf(String s)
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{
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return valueOf(parseLong(s, 10, false));
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}
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/**
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* Returns a <code>Long</code> object wrapping the value.
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*
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* @param val the value to wrap
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* @return the <code>Long</code>
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* @since 1.5
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*/
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public static Long valueOf(long val)
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{
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if (val < MIN_CACHE || val > MAX_CACHE)
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return new Long(val);
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else
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return longCache[((int)val) - MIN_CACHE];
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}
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/**
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* Convert the specified <code>String</code> into a <code>Long</code>.
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* The <code>String</code> may represent decimal, hexadecimal, or
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* octal numbers.
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*
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* <p>The extended BNF grammar is as follows:<br>
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* <pre>
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* <em>DecodableString</em>:
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* ( [ <code>-</code> ] <em>DecimalNumber</em> )
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* | ( [ <code>-</code> ] ( <code>0x</code> | <code>0X</code>
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* | <code>#</code> ) <em>HexDigit</em> { <em>HexDigit</em> } )
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* | ( [ <code>-</code> ] <code>0</code> { <em>OctalDigit</em> } )
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* <em>DecimalNumber</em>:
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* <em>DecimalDigit except '0'</em> { <em>DecimalDigit</em> }
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* <em>DecimalDigit</em>:
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* <em>Character.digit(d, 10) has value 0 to 9</em>
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* <em>OctalDigit</em>:
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* <em>Character.digit(d, 8) has value 0 to 7</em>
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* <em>DecimalDigit</em>:
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* <em>Character.digit(d, 16) has value 0 to 15</em>
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* </pre>
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* Finally, the value must be in the range <code>MIN_VALUE</code> to
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* <code>MAX_VALUE</code>, or an exception is thrown. Note that you cannot
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* use a trailing 'l' or 'L', unlike in Java source code.
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*
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* @param str the <code>String</code> to interpret
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* @return the value of the String as a <code>Long</code>
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* @throws NumberFormatException if <code>s</code> cannot be parsed as a
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* <code>long</code>
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* @throws NullPointerException if <code>s</code> is null
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* @since 1.2
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*/
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public static Long decode(String str)
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{
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return valueOf(parseLong(str, 10, true));
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}
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/**
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* Return the value of this <code>Long</code> as a <code>byte</code>.
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*
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* @return the byte value
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*/
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public byte byteValue()
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{
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return (byte) value;
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}
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/**
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* Return the value of this <code>Long</code> as a <code>short</code>.
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*
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* @return the short value
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*/
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public short shortValue()
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{
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return (short) value;
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}
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/**
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* Return the value of this <code>Long</code> as an <code>int</code>.
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*
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* @return the int value
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*/
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public int intValue()
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{
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return (int) value;
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}
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/**
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* Return the value of this <code>Long</code>.
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*
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* @return the long value
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*/
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public long longValue()
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{
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return value;
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}
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|
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/**
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* Return the value of this <code>Long</code> as a <code>float</code>.
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*
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* @return the float value
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*/
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public float floatValue()
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{
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return value;
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}
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|
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/**
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* Return the value of this <code>Long</code> as a <code>double</code>.
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*
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* @return the double value
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*/
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public double doubleValue()
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{
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return value;
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}
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|
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/**
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* Converts the <code>Long</code> value to a <code>String</code> and
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* assumes a radix of 10.
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*
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* @return the <code>String</code> representation
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*/
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public String toString()
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{
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return toString(value, 10);
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}
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|
|
/**
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|
* Return a hashcode representing this Object. <code>Long</code>'s hash
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|
* code is calculated by <code>(int) (value ^ (value >> 32))</code>.
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|
*
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* @return this Object's hash code
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*/
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|
public int hashCode()
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|
{
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return (int) (value ^ (value >>> 32));
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}
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|
|
/**
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|
* Returns <code>true</code> if <code>obj</code> is an instance of
|
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* <code>Long</code> and represents the same long value.
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|
*
|
|
* @param obj the object to compare
|
|
* @return whether these Objects are semantically equal
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*/
|
|
public boolean equals(Object obj)
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|
{
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return obj instanceof Long && value == ((Long) obj).value;
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}
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|
|
/**
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|
* Get the specified system property as a <code>Long</code>. The
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* <code>decode()</code> method will be used to interpret the value of
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* the property.
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*
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* @param nm the name of the system property
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* @return the system property as a <code>Long</code>, or null if the
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* property is not found or cannot be decoded
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|
* @throws SecurityException if accessing the system property is forbidden
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|
* @see System#getProperty(String)
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* @see #decode(String)
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*/
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|
public static Long getLong(String nm)
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{
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return getLong(nm, null);
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}
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|
|
/**
|
|
* Get the specified system property as a <code>Long</code>, or use a
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|
* default <code>long</code> value if the property is not found or is not
|
|
* decodable. The <code>decode()</code> method will be used to interpret
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* the value of the property.
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|
*
|
|
* @param nm the name of the system property
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|
* @param val the default value
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|
* @return the value of the system property, or the default
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|
* @throws SecurityException if accessing the system property is forbidden
|
|
* @see System#getProperty(String)
|
|
* @see #decode(String)
|
|
*/
|
|
public static Long getLong(String nm, long val)
|
|
{
|
|
Long result = getLong(nm, null);
|
|
return result == null ? valueOf(val) : result;
|
|
}
|
|
|
|
/**
|
|
* Get the specified system property as a <code>Long</code>, or use a
|
|
* default <code>Long</code> value if the property is not found or is
|
|
* not decodable. The <code>decode()</code> method will be used to
|
|
* interpret the value of the property.
|
|
*
|
|
* @param nm the name of the system property
|
|
* @param def the default value
|
|
* @return the value of the system property, or the default
|
|
* @throws SecurityException if accessing the system property is forbidden
|
|
* @see System#getProperty(String)
|
|
* @see #decode(String)
|
|
*/
|
|
public static Long getLong(String nm, Long def)
|
|
{
|
|
if (nm == null || "".equals(nm))
|
|
return def;
|
|
nm = System.getProperty(nm);
|
|
if (nm == null)
|
|
return def;
|
|
try
|
|
{
|
|
return decode(nm);
|
|
}
|
|
catch (NumberFormatException e)
|
|
{
|
|
return def;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Compare two Longs numerically by comparing their <code>long</code>
|
|
* values. The result is positive if the first is greater, negative if the
|
|
* second is greater, and 0 if the two are equal.
|
|
*
|
|
* @param l the Long to compare
|
|
* @return the comparison
|
|
* @since 1.2
|
|
*/
|
|
public int compareTo(Long l)
|
|
{
|
|
if (value == l.value)
|
|
return 0;
|
|
// Returns just -1 or 1 on inequality; doing math might overflow the long.
|
|
return value > l.value ? 1 : -1;
|
|
}
|
|
|
|
/**
|
|
* Compares two unboxed long values.
|
|
* The result is positive if the first is greater, negative if the second
|
|
* is greater, and 0 if the two are equal.
|
|
*
|
|
* @param x First value to compare.
|
|
* @param y Second value to compare.
|
|
*
|
|
* @return positive int if the first value is greater, negative if the second
|
|
* is greater, and 0 if the two are equal.
|
|
* @since 1.7
|
|
*/
|
|
public static int compare(long x, long y)
|
|
{
|
|
return Long.valueOf(x).compareTo(Long.valueOf(y));
|
|
}
|
|
|
|
/**
|
|
* Return the number of bits set in x.
|
|
* @param x value to examine
|
|
* @since 1.5
|
|
*/
|
|
public static int bitCount(long x)
|
|
{
|
|
// Successively collapse alternating bit groups into a sum.
|
|
x = ((x >> 1) & 0x5555555555555555L) + (x & 0x5555555555555555L);
|
|
x = ((x >> 2) & 0x3333333333333333L) + (x & 0x3333333333333333L);
|
|
int v = (int) ((x >>> 32) + x);
|
|
v = ((v >> 4) & 0x0f0f0f0f) + (v & 0x0f0f0f0f);
|
|
v = ((v >> 8) & 0x00ff00ff) + (v & 0x00ff00ff);
|
|
return ((v >> 16) & 0x0000ffff) + (v & 0x0000ffff);
|
|
}
|
|
|
|
/**
|
|
* Rotate x to the left by distance bits.
|
|
* @param x the value to rotate
|
|
* @param distance the number of bits by which to rotate
|
|
* @since 1.5
|
|
*/
|
|
public static long rotateLeft(long x, int distance)
|
|
{
|
|
// This trick works because the shift operators implicitly mask
|
|
// the shift count.
|
|
return (x << distance) | (x >>> - distance);
|
|
}
|
|
|
|
/**
|
|
* Rotate x to the right by distance bits.
|
|
* @param x the value to rotate
|
|
* @param distance the number of bits by which to rotate
|
|
* @since 1.5
|
|
*/
|
|
public static long rotateRight(long x, int distance)
|
|
{
|
|
// This trick works because the shift operators implicitly mask
|
|
// the shift count.
|
|
return (x << - distance) | (x >>> distance);
|
|
}
|
|
|
|
/**
|
|
* Find the highest set bit in value, and return a new value
|
|
* with only that bit set.
|
|
* @param value the value to examine
|
|
* @since 1.5
|
|
*/
|
|
public static long highestOneBit(long value)
|
|
{
|
|
value |= value >>> 1;
|
|
value |= value >>> 2;
|
|
value |= value >>> 4;
|
|
value |= value >>> 8;
|
|
value |= value >>> 16;
|
|
value |= value >>> 32;
|
|
return value ^ (value >>> 1);
|
|
}
|
|
|
|
/**
|
|
* Return the number of leading zeros in value.
|
|
* @param value the value to examine
|
|
* @since 1.5
|
|
*/
|
|
public static int numberOfLeadingZeros(long value)
|
|
{
|
|
value |= value >>> 1;
|
|
value |= value >>> 2;
|
|
value |= value >>> 4;
|
|
value |= value >>> 8;
|
|
value |= value >>> 16;
|
|
value |= value >>> 32;
|
|
return bitCount(~value);
|
|
}
|
|
|
|
/**
|
|
* Find the lowest set bit in value, and return a new value
|
|
* with only that bit set.
|
|
* @param value the value to examine
|
|
* @since 1.5
|
|
*/
|
|
public static long lowestOneBit(long value)
|
|
{
|
|
// Classic assembly trick.
|
|
return value & - value;
|
|
}
|
|
|
|
/**
|
|
* Find the number of trailing zeros in value.
|
|
* @param value the value to examine
|
|
* @since 1.5
|
|
*/
|
|
public static int numberOfTrailingZeros(long value)
|
|
{
|
|
return bitCount((value & -value) - 1);
|
|
}
|
|
|
|
/**
|
|
* Return 1 if x is positive, -1 if it is negative, and 0 if it is
|
|
* zero.
|
|
* @param x the value to examine
|
|
* @since 1.5
|
|
*/
|
|
public static int signum(long x)
|
|
{
|
|
return (int) ((x >> 63) | (-x >>> 63));
|
|
|
|
// The LHS propagates the sign bit through every bit in the word;
|
|
// if X < 0, every bit is set to 1, else 0. if X > 0, the RHS
|
|
// negates x and shifts the resulting 1 in the sign bit to the
|
|
// LSB, leaving every other bit 0.
|
|
|
|
// Hacker's Delight, Section 2-7
|
|
}
|
|
|
|
/**
|
|
* Reverse the bytes in val.
|
|
* @since 1.5
|
|
*/
|
|
public static long reverseBytes(long val)
|
|
{
|
|
int hi = Integer.reverseBytes((int) val);
|
|
int lo = Integer.reverseBytes((int) (val >>> 32));
|
|
return (((long) hi) << 32) | lo;
|
|
}
|
|
|
|
/**
|
|
* Reverse the bits in val.
|
|
* @since 1.5
|
|
*/
|
|
public static long reverse(long val)
|
|
{
|
|
long hi = Integer.reverse((int) val) & 0xffffffffL;
|
|
long lo = Integer.reverse((int) (val >>> 32)) & 0xffffffffL;
|
|
return (hi << 32) | lo;
|
|
}
|
|
|
|
/**
|
|
* Helper for converting unsigned numbers to String.
|
|
*
|
|
* @param num the number
|
|
* @param exp log2(digit) (ie. 1, 3, or 4 for binary, oct, hex)
|
|
*/
|
|
private static String toUnsignedString(long num, int exp)
|
|
{
|
|
// Compute string length
|
|
int size = 1;
|
|
long copy = num >>> exp;
|
|
while (copy != 0)
|
|
{
|
|
size++;
|
|
copy >>>= exp;
|
|
}
|
|
// Quick path for single character strings
|
|
if (size == 1)
|
|
return new String(digits, (int)num, 1, true);
|
|
|
|
// Encode into buffer
|
|
int mask = (1 << exp) - 1;
|
|
char[] buffer = new char[size];
|
|
int i = size;
|
|
do
|
|
{
|
|
buffer[--i] = digits[(int) num & mask];
|
|
num >>>= exp;
|
|
}
|
|
while (num != 0);
|
|
|
|
// Package constructor avoids an array copy.
|
|
return new String(buffer, i, size - i, true);
|
|
}
|
|
|
|
/**
|
|
* Helper for parsing longs.
|
|
*
|
|
* @param str the string to parse
|
|
* @param radix the radix to use, must be 10 if decode is true
|
|
* @param decode if called from decode
|
|
* @return the parsed long value
|
|
* @throws NumberFormatException if there is an error
|
|
* @throws NullPointerException if decode is true and str is null
|
|
* @see #parseLong(String, int)
|
|
* @see #decode(String)
|
|
*/
|
|
private static long parseLong(String str, int radix, boolean decode)
|
|
{
|
|
if (! decode && str == null)
|
|
throw new NumberFormatException();
|
|
int index = 0;
|
|
int len = str.length();
|
|
boolean isNeg = false;
|
|
if (len == 0)
|
|
throw new NumberFormatException();
|
|
int ch = str.charAt(index);
|
|
if (ch == '-')
|
|
{
|
|
if (len == 1)
|
|
throw new NumberFormatException();
|
|
isNeg = true;
|
|
ch = str.charAt(++index);
|
|
}
|
|
if (decode)
|
|
{
|
|
if (ch == '0')
|
|
{
|
|
if (++index == len)
|
|
return 0;
|
|
if ((str.charAt(index) & ~('x' ^ 'X')) == 'X')
|
|
{
|
|
radix = 16;
|
|
index++;
|
|
}
|
|
else
|
|
radix = 8;
|
|
}
|
|
else if (ch == '#')
|
|
{
|
|
radix = 16;
|
|
index++;
|
|
}
|
|
}
|
|
if (index == len)
|
|
throw new NumberFormatException();
|
|
|
|
long max = MAX_VALUE / radix;
|
|
// We can't directly write `max = (MAX_VALUE + 1) / radix'.
|
|
// So instead we fake it.
|
|
if (isNeg && MAX_VALUE % radix == radix - 1)
|
|
++max;
|
|
|
|
long val = 0;
|
|
while (index < len)
|
|
{
|
|
if (val < 0 || val > max)
|
|
throw new NumberFormatException();
|
|
|
|
ch = Character.digit(str.charAt(index++), radix);
|
|
val = val * radix + ch;
|
|
if (ch < 0 || (val < 0 && (! isNeg || val != MIN_VALUE)))
|
|
throw new NumberFormatException();
|
|
}
|
|
return isNeg ? -val : val;
|
|
}
|
|
}
|