| /* | |
| * Copyright (c) 1994, 2025, Oracle and/or its affiliates. All rights reserved. | |
| * 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. | |
| */ | |
| package java.lang; | |
| import java.lang.annotation.Native; | |
| import java.lang.invoke.MethodHandles; | |
| import java.lang.constant.Constable; | |
| import java.lang.constant.ConstantDesc; | |
| import java.math.*; | |
| import java.util.Objects; | |
| import java.util.Optional; | |
| import jdk.internal.misc.CDS; | |
| import jdk.internal.util.DecimalDigits; | |
| import jdk.internal.vm.annotation.ForceInline; | |
| import jdk.internal.vm.annotation.IntrinsicCandidate; | |
| import jdk.internal.vm.annotation.Stable; | |
| import static java.lang.Character.digit; | |
| import static java.lang.String.COMPACT_STRINGS; | |
| import static java.lang.String.LATIN1; | |
| import static java.lang.String.UTF16; | |
| /** | |
| * The {@code Long} class is the {@linkplain | |
| * java.lang##wrapperClass wrapper class} for values of the primitive | |
| * type {@code long}. An object of type {@code Long} contains a | |
| * single field whose type is {@code long}. | |
| * | |
| * <p> In addition, this class provides several methods for converting | |
| * a {@code long} to a {@code String} and a {@code String} to a {@code | |
| * long}, as well as other constants and methods useful when dealing | |
| * with a {@code long}. | |
| * | |
| * <p>This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a> | |
| * class; programmers should treat instances that are | |
| * {@linkplain #equals(Object) equal} as interchangeable and should not | |
| * use instances for synchronization, or unpredictable behavior may | |
| * occur. For example, in a future release, synchronization may fail. | |
| * | |
| * <p>Implementation note: The implementations of the "bit twiddling" | |
| * methods (such as {@link #highestOneBit(long) highestOneBit} and | |
| * {@link #numberOfTrailingZeros(long) numberOfTrailingZeros}) are | |
| * based on material from Henry S. Warren, Jr.'s <cite>Hacker's | |
| * Delight</cite>, (Addison Wesley, 2002) and <cite>Hacker's | |
| * Delight, Second Edition</cite>, (Pearson Education, 2013). | |
| * | |
| * @author Lee Boynton | |
| * @author Arthur van Hoff | |
| * @author Josh Bloch | |
| * @author Joseph D. Darcy | |
| * @since 1.0 | |
| */ | |
| @jdk.internal.ValueBased | |
| public final class Long extends Number | |
| implements Comparable<Long>, Constable, ConstantDesc { | |
| /** | |
| * A constant holding the minimum value a {@code long} can | |
| * have, -2<sup>63</sup>. | |
| */ | |
| @Native public static final long MIN_VALUE = 0x8000000000000000L; | |
| /** | |
| * A constant holding the maximum value a {@code long} can | |
| * have, 2<sup>63</sup>-1. | |
| */ | |
| @Native public static final long MAX_VALUE = 0x7fffffffffffffffL; | |
| /** | |
| * The {@code Class} instance representing the primitive type | |
| * {@code long}. | |
| * | |
| * @since 1.1 | |
| */ | |
| public static final Class<Long> TYPE = Class.getPrimitiveClass("long"); | |
| /** | |
| * Returns a string representation of the first argument in the | |
| * radix specified by the second argument. | |
| * | |
| * <p>If the radix is smaller than {@code Character.MIN_RADIX} | |
| * or larger than {@code Character.MAX_RADIX}, then the radix | |
| * {@code 10} is used instead. | |
| * | |
| * <p>If the first argument is negative, the first element of the | |
| * result is the ASCII minus sign {@code '-'} | |
| * ({@code '\u005Cu002d'}). If the first argument is not | |
| * negative, no sign character appears in the result. | |
| * | |
| * <p>The remaining characters of the result represent the magnitude | |
| * of the first argument. If the magnitude is zero, it is | |
| * represented by a single zero character {@code '0'} | |
| * ({@code '\u005Cu0030'}); otherwise, the first character of | |
| * the representation of the magnitude will not be the zero | |
| * character. The following ASCII characters are used as digits: | |
| * | |
| * <blockquote> | |
| * {@code 0123456789abcdefghijklmnopqrstuvwxyz} | |
| * </blockquote> | |
| * | |
| * These are {@code '\u005Cu0030'} through | |
| * {@code '\u005Cu0039'} and {@code '\u005Cu0061'} through | |
| * {@code '\u005Cu007a'}. If {@code radix} is | |
| * <var>N</var>, then the first <var>N</var> of these characters | |
| * are used as radix-<var>N</var> digits in the order shown. Thus, | |
| * the digits for hexadecimal (radix 16) are | |
| * {@code 0123456789abcdef}. If uppercase letters are | |
| * desired, the {@link java.lang.String#toUpperCase()} method may | |
| * be called on the result: | |
| * | |
| * <blockquote> | |
| * {@code Long.toString(n, 16).toUpperCase()} | |
| * </blockquote> | |
| * | |
| * @param i a {@code long} to be converted to a string. | |
| * @param radix the radix to use in the string representation. | |
| * @return a string representation of the argument in the specified radix. | |
| * @see java.lang.Character#MAX_RADIX | |
| * @see java.lang.Character#MIN_RADIX | |
| */ | |
| public static String toString(long i, int radix) { | |
| if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX) | |
| radix = 10; | |
| if (radix == 10) | |
| return toString(i); | |
| if (COMPACT_STRINGS) { | |
| byte[] buf = new byte[65]; | |
| int charPos = 64; | |
| boolean negative = (i < 0); | |
| if (!negative) { | |
| i = -i; | |
| } | |
| while (i <= -radix) { | |
| buf[charPos--] = Integer.digits[(int)(-(i % radix))]; | |
| i = i / radix; | |
| } | |
| buf[charPos] = Integer.digits[(int)(-i)]; | |
| if (negative) { | |
| buf[--charPos] = '-'; | |
| } | |
| return StringLatin1.newString(buf, charPos, (65 - charPos)); | |
| } | |
| return toStringUTF16(i, radix); | |
| } | |
| private static String toStringUTF16(long i, int radix) { | |
| byte[] buf = new byte[65 * 2]; | |
| int charPos = 64; | |
| boolean negative = (i < 0); | |
| if (!negative) { | |
| i = -i; | |
| } | |
| while (i <= -radix) { | |
| StringUTF16.putChar(buf, charPos--, Integer.digits[(int)(-(i % radix))]); | |
| i = i / radix; | |
| } | |
| StringUTF16.putChar(buf, charPos, Integer.digits[(int)(-i)]); | |
| if (negative) { | |
| StringUTF16.putChar(buf, --charPos, '-'); | |
| } | |
| return StringUTF16.newString(buf, charPos, (65 - charPos)); | |
| } | |
| /** | |
| * Returns a string representation of the first argument as an | |
| * unsigned integer value in the radix specified by the second | |
| * argument. | |
| * | |
| * <p>If the radix is smaller than {@code Character.MIN_RADIX} | |
| * or larger than {@code Character.MAX_RADIX}, then the radix | |
| * {@code 10} is used instead. | |
| * | |
| * <p>Note that since the first argument is treated as an unsigned | |
| * value, no leading sign character is printed. | |
| * | |
| * <p>If the magnitude is zero, it is represented by a single zero | |
| * character {@code '0'} ({@code '\u005Cu0030'}); otherwise, | |
| * the first character of the representation of the magnitude will | |
| * not be the zero character. | |
| * | |
| * <p>The behavior of radixes and the characters used as digits | |
| * are the same as {@link #toString(long, int) toString}. | |
| * | |
| * @param i an integer to be converted to an unsigned string. | |
| * @param radix the radix to use in the string representation. | |
| * @return an unsigned string representation of the argument in the specified radix. | |
| * @see #toString(long, int) | |
| * @since 1.8 | |
| */ | |
| public static String toUnsignedString(long i, int radix) { | |
| if (i >= 0) | |
| return toString(i, radix); | |
| else { | |
| return switch (radix) { | |
| case 2 -> toBinaryString(i); | |
| case 4 -> toUnsignedString0(i, 2); | |
| case 8 -> toOctalString(i); | |
| case 10 -> { | |
| /* | |
| * We can get the effect of an unsigned division by 10 | |
| * on a long value by first shifting right, yielding a | |
| * positive value, and then dividing by 5. This | |
| * allows the last digit and preceding digits to be | |
| * isolated more quickly than by an initial conversion | |
| * to BigInteger. | |
| */ | |
| long quot = (i >>> 1) / 5; | |
| long rem = i - quot * 10; | |
| yield toString(quot) + rem; | |
| } | |
| case 16 -> toHexString(i); | |
| case 32 -> toUnsignedString0(i, 5); | |
| default -> toUnsignedBigInteger(i).toString(radix); | |
| }; | |
| } | |
| } | |
| /** | |
| * Return a BigInteger equal to the unsigned value of the | |
| * argument. | |
| */ | |
| private static BigInteger toUnsignedBigInteger(long i) { | |
| if (i >= 0L) | |
| return BigInteger.valueOf(i); | |
| else { | |
| int upper = (int) (i >>> 32); | |
| int lower = (int) i; | |
| // return (upper << 32) + lower | |
| return (BigInteger.valueOf(Integer.toUnsignedLong(upper))).shiftLeft(32). | |
| add(BigInteger.valueOf(Integer.toUnsignedLong(lower))); | |
| } | |
| } | |
| /** | |
| * Returns a string representation of the {@code long} | |
| * argument as an unsigned integer in base 16. | |
| * | |
| * <p>The unsigned {@code long} value is the argument plus | |
| * 2<sup>64</sup> if the argument is negative; otherwise, it is | |
| * equal to the argument. This value is converted to a string of | |
| * ASCII digits in hexadecimal (base 16) with no extra | |
| * leading {@code 0}s. | |
| * | |
| * <p>The value of the argument can be recovered from the returned | |
| * string {@code s} by calling {@link | |
| * Long#parseUnsignedLong(String, int) Long.parseUnsignedLong(s, | |
| * 16)}. | |
| * | |
| * <p>If the unsigned magnitude is zero, it is represented by a | |
| * single zero character {@code '0'} ({@code '\u005Cu0030'}); | |
| * otherwise, the first character of the representation of the | |
| * unsigned magnitude will not be the zero character. The | |
| * following characters are used as hexadecimal digits: | |
| * | |
| * <blockquote> | |
| * {@code 0123456789abcdef} | |
| * </blockquote> | |
| * | |
| * These are the characters {@code '\u005Cu0030'} through | |
| * {@code '\u005Cu0039'} and {@code '\u005Cu0061'} through | |
| * {@code '\u005Cu0066'}. If uppercase letters are desired, | |
| * the {@link java.lang.String#toUpperCase()} method may be called | |
| * on the result: | |
| * | |
| * <blockquote> | |
| * {@code Long.toHexString(n).toUpperCase()} | |
| * </blockquote> | |
| * | |
| * @apiNote | |
| * The {@link java.util.HexFormat} class provides formatting and parsing | |
| * of byte arrays and primitives to return a string or adding to an {@link Appendable}. | |
| * {@code HexFormat} formats and parses uppercase or lowercase hexadecimal characters, | |
| * with leading zeros and for byte arrays includes for each byte | |
| * a delimiter, prefix, and suffix. | |
| * | |
| * @param i a {@code long} to be converted to a string. | |
| * @return the string representation of the unsigned {@code long} | |
| * value represented by the argument in hexadecimal | |
| * (base 16). | |
| * @see java.util.HexFormat | |
| * @see #parseUnsignedLong(String, int) | |
| * @see #toUnsignedString(long, int) | |
| * @since 1.0.2 | |
| */ | |
| public static String toHexString(long i) { | |
| return toUnsignedString0(i, 4); | |
| } | |
| /** | |
| * Returns a string representation of the {@code long} | |
| * argument as an unsigned integer in base 8. | |
| * | |
| * <p>The unsigned {@code long} value is the argument plus | |
| * 2<sup>64</sup> if the argument is negative; otherwise, it is | |
| * equal to the argument. This value is converted to a string of | |
| * ASCII digits in octal (base 8) with no extra leading | |
| * {@code 0}s. | |
| * | |
| * <p>The value of the argument can be recovered from the returned | |
| * string {@code s} by calling {@link | |
| * Long#parseUnsignedLong(String, int) Long.parseUnsignedLong(s, | |
| * 8)}. | |
| * | |
| * <p>If the unsigned magnitude is zero, it is represented by a | |
| * single zero character {@code '0'} ({@code '\u005Cu0030'}); | |
| * otherwise, the first character of the representation of the | |
| * unsigned magnitude will not be the zero character. The | |
| * following characters are used as octal digits: | |
| * | |
| * <blockquote> | |
| * {@code 01234567} | |
| * </blockquote> | |
| * | |
| * These are the characters {@code '\u005Cu0030'} through | |
| * {@code '\u005Cu0037'}. | |
| * | |
| * @param i a {@code long} to be converted to a string. | |
| * @return the string representation of the unsigned {@code long} | |
| * value represented by the argument in octal (base 8). | |
| * @see #parseUnsignedLong(String, int) | |
| * @see #toUnsignedString(long, int) | |
| * @since 1.0.2 | |
| */ | |
| public static String toOctalString(long i) { | |
| return toUnsignedString0(i, 3); | |
| } | |
| /** | |
| * Returns a string representation of the {@code long} | |
| * argument as an unsigned integer in base 2. | |
| * | |
| * <p>The unsigned {@code long} value is the argument plus | |
| * 2<sup>64</sup> if the argument is negative; otherwise, it is | |
| * equal to the argument. This value is converted to a string of | |
| * ASCII digits in binary (base 2) with no extra leading | |
| * {@code 0}s. | |
| * | |
| * <p>The value of the argument can be recovered from the returned | |
| * string {@code s} by calling {@link | |
| * Long#parseUnsignedLong(String, int) Long.parseUnsignedLong(s, | |
| * 2)}. | |
| * | |
| * <p>If the unsigned magnitude is zero, it is represented by a | |
| * single zero character {@code '0'} ({@code '\u005Cu0030'}); | |
| * otherwise, the first character of the representation of the | |
| * unsigned magnitude will not be the zero character. The | |
| * characters {@code '0'} ({@code '\u005Cu0030'}) and {@code | |
| * '1'} ({@code '\u005Cu0031'}) are used as binary digits. | |
| * | |
| * @param i a {@code long} to be converted to a string. | |
| * @return the string representation of the unsigned {@code long} | |
| * value represented by the argument in binary (base 2). | |
| * @see #parseUnsignedLong(String, int) | |
| * @see #toUnsignedString(long, int) | |
| * @since 1.0.2 | |
| */ | |
| public static String toBinaryString(long i) { | |
| return toUnsignedString0(i, 1); | |
| } | |
| /** | |
| * Format a long (treated as unsigned) into a String. | |
| * @param val the value to format | |
| * @param shift the log2 of the base to format in (4 for hex, 3 for octal, 1 for binary) | |
| */ | |
| static String toUnsignedString0(long val, int shift) { | |
| // assert shift > 0 && shift <=5 : "Illegal shift value"; | |
| int mag = Long.SIZE - Long.numberOfLeadingZeros(val); | |
| int chars = Math.max(((mag + (shift - 1)) / shift), 1); | |
| if (COMPACT_STRINGS) { | |
| byte[] buf = new byte[chars]; | |
| formatUnsignedLong0(val, shift, buf, 0, chars); | |
| return new String(buf, LATIN1); | |
| } else { | |
| byte[] buf = new byte[chars * 2]; | |
| formatUnsignedLong0UTF16(val, shift, buf, 0, chars); | |
| return new String(buf, UTF16); | |
| } | |
| } | |
| /** | |
| * Format a long (treated as unsigned) into a byte buffer (LATIN1 version). If | |
| * {@code len} exceeds the formatted ASCII representation of {@code val}, | |
| * {@code buf} will be padded with leading zeroes. | |
| * | |
| * @param val the unsigned long to format | |
| * @param shift the log2 of the base to format in (4 for hex, 3 for octal, 1 for binary) | |
| * @param buf the byte buffer to write to | |
| * @param offset the offset in the destination buffer to start at | |
| * @param len the number of characters to write | |
| */ | |
| private static void formatUnsignedLong0(long val, int shift, byte[] buf, int offset, int len) { | |
| int charPos = offset + len; | |
| int radix = 1 << shift; | |
| int mask = radix - 1; | |
| do { | |
| buf[--charPos] = Integer.digits[((int) val) & mask]; | |
| val >>>= shift; | |
| } while (charPos > offset); | |
| } | |
| /** | |
| * Format a long (treated as unsigned) into a byte buffer (UTF16 version). If | |
| * {@code len} exceeds the formatted ASCII representation of {@code val}, | |
| * {@code buf} will be padded with leading zeroes. | |
| * | |
| * @param val the unsigned long to format | |
| * @param shift the log2 of the base to format in (4 for hex, 3 for octal, 1 for binary) | |
| * @param buf the byte buffer to write to | |
| * @param offset the offset in the destination buffer to start at | |
| * @param len the number of characters to write | |
| */ | |
| private static void formatUnsignedLong0UTF16(long val, int shift, byte[] buf, int offset, int len) { | |
| int charPos = offset + len; | |
| int radix = 1 << shift; | |
| int mask = radix - 1; | |
| do { | |
| StringUTF16.putChar(buf, --charPos, Integer.digits[((int) val) & mask]); | |
| val >>>= shift; | |
| } while (charPos > offset); | |
| } | |
| /** | |
| * Returns a {@code String} object representing the specified | |
| * {@code long}. The argument is converted to signed decimal | |
| * representation and returned as a string, exactly as if the | |
| * argument and the radix 10 were given as arguments to the {@link | |
| * #toString(long, int)} method. | |
| * | |
| * @param i a {@code long} to be converted. | |
| * @return a string representation of the argument in base 10. | |
| */ | |
| public static String toString(long i) { | |
| int size = DecimalDigits.stringSize(i); | |
| if (COMPACT_STRINGS) { | |
| byte[] buf = new byte[size]; | |
| DecimalDigits.uncheckedGetCharsLatin1(i, size, buf); | |
| return new String(buf, LATIN1); | |
| } else { | |
| byte[] buf = new byte[size * 2]; | |
| DecimalDigits.uncheckedGetCharsUTF16(i, size, buf); | |
| return new String(buf, UTF16); | |
| } | |
| } | |
| /** | |
| * Returns a string representation of the argument as an unsigned | |
| * decimal value. | |
| * | |
| * The argument is converted to unsigned decimal representation | |
| * and returned as a string exactly as if the argument and radix | |
| * 10 were given as arguments to the {@link #toUnsignedString(long, | |
| * int)} method. | |
| * | |
| * @param i an integer to be converted to an unsigned string. | |
| * @return an unsigned string representation of the argument. | |
| * @see #toUnsignedString(long, int) | |
| * @since 1.8 | |
| */ | |
| public static String toUnsignedString(long i) { | |
| return toUnsignedString(i, 10); | |
| } | |
| /** | |
| * Parses the string argument as a signed {@code long} in the | |
| * radix specified by the second argument. The characters in the | |
| * string must all be digits of the specified radix (as determined | |
| * by whether {@link java.lang.Character#digit(char, int)} returns | |
| * a nonnegative value), except that the first character may be an | |
| * ASCII minus sign {@code '-'} ({@code '\u005Cu002D'}) to | |
| * indicate a negative value or an ASCII plus sign {@code '+'} | |
| * ({@code '\u005Cu002B'}) to indicate a positive value. The | |
| * resulting {@code long} value is returned. | |
| * | |
| * <p>Note that neither the character {@code L} | |
| * ({@code '\u005Cu004C'}) nor {@code l} | |
| * ({@code '\u005Cu006C'}) is permitted to appear at the end | |
| * of the string as a type indicator, as would be permitted in | |
| * Java programming language source code - except that either | |
| * {@code L} or {@code l} may appear as a digit for a | |
| * radix greater than or equal to 22. | |
| * | |
| * <p>An exception of type {@code NumberFormatException} is | |
| * thrown if any of the following situations occurs: | |
| * <ul> | |
| * | |
| * <li>The first argument is {@code null} or is a string of | |
| * length zero. | |
| * | |
| * <li>The {@code radix} is either smaller than {@link | |
| * java.lang.Character#MIN_RADIX} or larger than {@link | |
| * java.lang.Character#MAX_RADIX}. | |
| * | |
| * <li>Any character of the string is not a digit of the specified | |
| * radix, except that the first character may be a minus sign | |
| * {@code '-'} ({@code '\u005Cu002d'}) or plus sign {@code | |
| * '+'} ({@code '\u005Cu002B'}) provided that the string is | |
| * longer than length 1. | |
| * | |
| * <li>The value represented by the string is not a value of type | |
| * {@code long}. | |
| * </ul> | |
| * | |
| * <p>Examples: | |
| * <blockquote><pre> | |
| * parseLong("0", 10) returns 0L | |
| * parseLong("473", 10) returns 473L | |
| * parseLong("+42", 10) returns 42L | |
| * parseLong("-0", 10) returns 0L | |
| * parseLong("-FF", 16) returns -255L | |
| * parseLong("1100110", 2) returns 102L | |
| * parseLong("99", 8) throws a NumberFormatException | |
| * parseLong("Hazelnut", 10) throws a NumberFormatException | |
| * parseLong("Hazelnut", 36) returns 1356099454469L | |
| * </pre></blockquote> | |
| * | |
| * @param s the {@code String} containing the | |
| * {@code long} representation to be parsed. | |
| * @param radix the radix to be used while parsing {@code s}. | |
| * @return the {@code long} represented by the string argument in | |
| * the specified radix. | |
| * @throws NumberFormatException if the string does not contain a | |
| * parsable {@code long}. | |
| */ | |
| public static long parseLong(String s, int radix) | |
| throws NumberFormatException { | |
| if (s == null) { | |
| throw new NumberFormatException("Cannot parse null string"); | |
| } | |
| if (radix < Character.MIN_RADIX) { | |
| throw new NumberFormatException(String.format( | |
| "radix %s less than Character.MIN_RADIX", radix)); | |
| } | |
| if (radix > Character.MAX_RADIX) { | |
| throw new NumberFormatException(String.format( | |
| "radix %s greater than Character.MAX_RADIX", radix)); | |
| } | |
| int len = s.length(); | |
| if (len == 0) { | |
| throw NumberFormatException.forInputString("", radix); | |
| } | |
| int digit = ~0xFF; | |
| int i = 0; | |
| char firstChar = s.charAt(i++); | |
| if (firstChar != '-' && firstChar != '+') { | |
| digit = digit(firstChar, radix); | |
| } | |
| if (digit >= 0 || digit == ~0xFF && len > 1) { | |
| long limit = firstChar != '-' ? MIN_VALUE + 1 : MIN_VALUE; | |
| long multmin = limit / radix; | |
| long result = -(digit & 0xFF); | |
| boolean inRange = true; | |
| /* Accumulating negatively avoids surprises near MAX_VALUE */ | |
| while (i < len && (digit = digit(s.charAt(i++), radix)) >= 0 | |
| && (inRange = result > multmin | |
| || result == multmin && digit <= (int) (radix * multmin - limit))) { | |
| result = radix * result - digit; | |
| } | |
| if (inRange && i == len && digit >= 0) { | |
| return firstChar != '-' ? -result : result; | |
| } | |
| } | |
| throw NumberFormatException.forInputString(s, radix); | |
| } | |
| /** | |
| * Parses the {@link CharSequence} argument as a signed {@code long} in | |
| * the specified {@code radix}, beginning at the specified | |
| * {@code beginIndex} and extending to {@code endIndex - 1}. | |
| * | |
| * <p>The method does not take steps to guard against the | |
| * {@code CharSequence} being mutated while parsing. | |
| * | |
| * @param s the {@code CharSequence} containing the {@code long} | |
| * representation to be parsed | |
| * @param beginIndex the beginning index, inclusive. | |
| * @param endIndex the ending index, exclusive. | |
| * @param radix the radix to be used while parsing {@code s}. | |
| * @return the signed {@code long} represented by the subsequence in | |
| * the specified radix. | |
| * @throws NullPointerException if {@code s} is null. | |
| * @throws IndexOutOfBoundsException if {@code beginIndex} is | |
| * negative, or if {@code beginIndex} is greater than | |
| * {@code endIndex} or if {@code endIndex} is greater than | |
| * {@code s.length()}. | |
| * @throws NumberFormatException if the {@code CharSequence} does not | |
| * contain a parsable {@code long} in the specified | |
| * {@code radix}, or if {@code radix} is either smaller than | |
| * {@link java.lang.Character#MIN_RADIX} or larger than | |
| * {@link java.lang.Character#MAX_RADIX}. | |
| * @since 9 | |
| */ | |
| public static long parseLong(CharSequence s, int beginIndex, int endIndex, int radix) | |
| throws NumberFormatException { | |
| Objects.requireNonNull(s); | |
| Objects.checkFromToIndex(beginIndex, endIndex, s.length()); | |
| if (radix < Character.MIN_RADIX) { | |
| throw new NumberFormatException(String.format( | |
| "radix %s less than Character.MIN_RADIX", radix)); | |
| } | |
| if (radix > Character.MAX_RADIX) { | |
| throw new NumberFormatException(String.format( | |
| "radix %s greater than Character.MAX_RADIX", radix)); | |
| } | |
| /* | |
| * While s can be concurrently modified, it is ensured that each | |
| * of its characters is read at most once, from lower to higher indices. | |
| * This is obtained by reading them using the pattern s.charAt(i++), | |
| * and by not updating i anywhere else. | |
| */ | |
| if (beginIndex == endIndex) { | |
| throw NumberFormatException.forInputString("", radix); | |
| } | |
| int digit = ~0xFF; // ~0xFF means firstChar char is sign | |
| int i = beginIndex; | |
| char firstChar = s.charAt(i++); | |
| if (firstChar != '-' && firstChar != '+') { | |
| digit = digit(firstChar, radix); | |
| } | |
| if (digit >= 0 || digit == ~0xFF && endIndex - beginIndex > 1) { | |
| long limit = firstChar != '-' ? MIN_VALUE + 1 : MIN_VALUE; | |
| long multmin = limit / radix; | |
| long result = -(digit & 0xFF); | |
| boolean inRange = true; | |
| /* Accumulating negatively avoids surprises near MAX_VALUE */ | |
| while (i < endIndex && (digit = digit(s.charAt(i++), radix)) >= 0 | |
| && (inRange = result > multmin | |
| || result == multmin && digit <= (int) (radix * multmin - limit))) { | |
| result = radix * result - digit; | |
| } | |
| if (inRange && i == endIndex && digit >= 0) { | |
| return firstChar != '-' ? -result : result; | |
| } | |
| } | |
| throw NumberFormatException.forCharSequence(s, beginIndex, | |
| endIndex, i - (digit < -1 ? 0 : 1)); | |
| } | |
| /** | |
| * Parses the string argument as a signed decimal {@code long}. | |
| * The characters in the string must all be decimal digits, except | |
| * that the first character may be an ASCII minus sign {@code '-'} | |
| * ({@code \u005Cu002D'}) to indicate a negative value or an | |
| * ASCII plus sign {@code '+'} ({@code '\u005Cu002B'}) to | |
| * indicate a positive value. The resulting {@code long} value is | |
| * returned, exactly as if the argument and the radix {@code 10} | |
| * were given as arguments to the {@link | |
| * #parseLong(java.lang.String, int)} method. | |
| * | |
| * <p>Note that neither the character {@code L} | |
| * ({@code '\u005Cu004C'}) nor {@code l} | |
| * ({@code '\u005Cu006C'}) is permitted to appear at the end | |
| * of the string as a type indicator, as would be permitted in | |
| * Java programming language source code. | |
| * | |
| * @param s a {@code String} containing the {@code long} | |
| * representation to be parsed | |
| * @return the {@code long} represented by the argument in | |
| * decimal. | |
| * @throws NumberFormatException if the string does not contain a | |
| * parsable {@code long}. | |
| */ | |
| public static long parseLong(String s) throws NumberFormatException { | |
| return parseLong(s, 10); | |
| } | |
| /** | |
| * Parses the string argument as an unsigned {@code long} in the | |
| * radix specified by the second argument. An unsigned integer | |
| * maps the values usually associated with negative numbers to | |
| * positive numbers larger than {@code MAX_VALUE}. | |
| * | |
| * The characters in the string must all be digits of the | |
| * specified radix (as determined by whether {@link | |
| * java.lang.Character#digit(char, int)} returns a nonnegative | |
| * value), except that the first character may be an ASCII plus | |
| * sign {@code '+'} ({@code '\u005Cu002B'}). The resulting | |
| * integer value is returned. | |
| * | |
| * <p>An exception of type {@code NumberFormatException} is | |
| * thrown if any of the following situations occurs: | |
| * <ul> | |
| * <li>The first argument is {@code null} or is a string of | |
| * length zero. | |
| * | |
| * <li>The radix is either smaller than | |
| * {@link java.lang.Character#MIN_RADIX} or | |
| * larger than {@link java.lang.Character#MAX_RADIX}. | |
| * | |
| * <li>Any character of the string is not a digit of the specified | |
| * radix, except that the first character may be a plus sign | |
| * {@code '+'} ({@code '\u005Cu002B'}) provided that the | |
| * string is longer than length 1. | |
| * | |
| * <li>The value represented by the string is larger than the | |
| * largest unsigned {@code long}, 2<sup>64</sup>-1. | |
| * | |
| * </ul> | |
| * | |
| * | |
| * @param s the {@code String} containing the unsigned integer | |
| * representation to be parsed | |
| * @param radix the radix to be used while parsing {@code s}. | |
| * @return the unsigned {@code long} represented by the string | |
| * argument in the specified radix. | |
| * @throws NumberFormatException if the {@code String} | |
| * does not contain a parsable {@code long}. | |
| * @since 1.8 | |
| */ | |
| public static long parseUnsignedLong(String s, int radix) | |
| throws NumberFormatException { | |
| if (s == null) { | |
| throw new NumberFormatException("Cannot parse null string"); | |
| } | |
| if (radix < Character.MIN_RADIX) { | |
| throw new NumberFormatException(String.format( | |
| "radix %s less than Character.MIN_RADIX", radix)); | |
| } | |
| if (radix > Character.MAX_RADIX) { | |
| throw new NumberFormatException(String.format( | |
| "radix %s greater than Character.MAX_RADIX", radix)); | |
| } | |
| int len = s.length(); | |
| if (len == 0) { | |
| throw NumberFormatException.forInputString(s, radix); | |
| } | |
| int i = 0; | |
| char firstChar = s.charAt(i++); | |
| if (firstChar == '-') { | |
| throw new NumberFormatException(String.format( | |
| "Illegal leading minus sign on unsigned string %s.", s)); | |
| } | |
| int digit = ~0xFF; | |
| if (firstChar != '+') { | |
| digit = digit(firstChar, radix); | |
| } | |
| if (digit >= 0 || digit == ~0xFF && len > 1) { | |
| long multmax = divideUnsigned(-1L, radix); // -1L is max unsigned long | |
| long result = digit & 0xFF; | |
| boolean inRange = true; | |
| while (i < len && (digit = digit(s.charAt(i++), radix)) >= 0 | |
| && (inRange = compareUnsigned(result, multmax) < 0 | |
| || result == multmax && digit < (int) (-radix * multmax))) { | |
| result = radix * result + digit; | |
| } | |
| if (inRange && i == len && digit >= 0) { | |
| return result; | |
| } | |
| } | |
| if (digit < 0) { | |
| throw NumberFormatException.forInputString(s, radix); | |
| } | |
| throw new NumberFormatException(String.format( | |
| "String value %s exceeds range of unsigned long.", s)); | |
| } | |
| /** | |
| * Parses the {@link CharSequence} argument as an unsigned {@code long} in | |
| * the specified {@code radix}, beginning at the specified | |
| * {@code beginIndex} and extending to {@code endIndex - 1}. | |
| * | |
| * <p>The method does not take steps to guard against the | |
| * {@code CharSequence} being mutated while parsing. | |
| * | |
| * @param s the {@code CharSequence} containing the unsigned | |
| * {@code long} representation to be parsed | |
| * @param beginIndex the beginning index, inclusive. | |
| * @param endIndex the ending index, exclusive. | |
| * @param radix the radix to be used while parsing {@code s}. | |
| * @return the unsigned {@code long} represented by the subsequence in | |
| * the specified radix. | |
| * @throws NullPointerException if {@code s} is null. | |
| * @throws IndexOutOfBoundsException if {@code beginIndex} is | |
| * negative, or if {@code beginIndex} is greater than | |
| * {@code endIndex} or if {@code endIndex} is greater than | |
| * {@code s.length()}. | |
| * @throws NumberFormatException if the {@code CharSequence} does not | |
| * contain a parsable unsigned {@code long} in the specified | |
| * {@code radix}, or if {@code radix} is either smaller than | |
| * {@link java.lang.Character#MIN_RADIX} or larger than | |
| * {@link java.lang.Character#MAX_RADIX}. | |
| * @since 9 | |
| */ | |
| public static long parseUnsignedLong(CharSequence s, int beginIndex, int endIndex, int radix) | |
| throws NumberFormatException { | |
| Objects.requireNonNull(s); | |
| Objects.checkFromToIndex(beginIndex, endIndex, s.length()); | |
| if (radix < Character.MIN_RADIX) { | |
| throw new NumberFormatException(String.format( | |
| "radix %s less than Character.MIN_RADIX", radix)); | |
| } | |
| if (radix > Character.MAX_RADIX) { | |
| throw new NumberFormatException(String.format( | |
| "radix %s greater than Character.MAX_RADIX", radix)); | |
| } | |
| /* | |
| * While s can be concurrently modified, it is ensured that each | |
| * of its characters is read at most once, from lower to higher indices. | |
| * This is obtained by reading them using the pattern s.charAt(i++), | |
| * and by not updating i anywhere else. | |
| */ | |
| if (beginIndex == endIndex) { | |
| throw NumberFormatException.forInputString("", radix); | |
| } | |
| int i = beginIndex; | |
| char firstChar = s.charAt(i++); | |
| if (firstChar == '-') { | |
| throw new NumberFormatException( | |
| "Illegal leading minus sign on unsigned string " + s + "."); | |
| } | |
| int digit = ~0xFF; | |
| if (firstChar != '+') { | |
| digit = digit(firstChar, radix); | |
| } | |
| if (digit >= 0 || digit == ~0xFF && endIndex - beginIndex > 1) { | |
| long multmax = divideUnsigned(-1L, radix); // -1L is max unsigned long | |
| long result = digit & 0xFF; | |
| boolean inRange = true; | |
| while (i < endIndex && (digit = digit(s.charAt(i++), radix)) >= 0 | |
| && (inRange = compareUnsigned(result, multmax) < 0 | |
| || result == multmax && digit < (int) (-radix * multmax))) { | |
| result = radix * result + digit; | |
| } | |
| if (inRange && i == endIndex && digit >= 0) { | |
| return result; | |
| } | |
| } | |
| if (digit < 0) { | |
| throw NumberFormatException.forCharSequence(s, beginIndex, | |
| endIndex, i - (digit < -1 ? 0 : 1)); | |
| } | |
| throw new NumberFormatException(String.format( | |
| "String value %s exceeds range of unsigned long.", s)); | |
| } | |
| /** | |
| * Parses the string argument as an unsigned decimal {@code long}. The | |
| * characters in the string must all be decimal digits, except | |
| * that the first character may be an ASCII plus sign {@code | |
| * '+'} ({@code '\u005Cu002B'}). The resulting integer value | |
| * is returned, exactly as if the argument and the radix 10 were | |
| * given as arguments to the {@link | |
| * #parseUnsignedLong(java.lang.String, int)} method. | |
| * | |
| * @param s a {@code String} containing the unsigned {@code long} | |
| * representation to be parsed | |
| * @return the unsigned {@code long} value represented by the decimal string argument | |
| * @throws NumberFormatException if the string does not contain a | |
| * parsable unsigned integer. | |
| * @since 1.8 | |
| */ | |
| public static long parseUnsignedLong(String s) throws NumberFormatException { | |
| return parseUnsignedLong(s, 10); | |
| } | |
| /** | |
| * Returns a {@code Long} object holding the value | |
| * extracted from the specified {@code String} when parsed | |
| * with the radix given by the second argument. The first | |
| * argument is interpreted as representing a signed | |
| * {@code long} in the radix specified by the second | |
| * argument, exactly as if the arguments were given to the {@link | |
| * #parseLong(java.lang.String, int)} method. The result is a | |
| * {@code Long} object that represents the {@code long} | |
| * value specified by the string. | |
| * | |
| * <p>In other words, this method returns a {@code Long} object equal | |
| * to the value of: | |
| * | |
| * <blockquote> | |
| * {@code Long.valueOf(Long.parseLong(s, radix))} | |
| * </blockquote> | |
| * | |
| * @param s the string to be parsed | |
| * @param radix the radix to be used in interpreting {@code s} | |
| * @return a {@code Long} object holding the value | |
| * represented by the string argument in the specified | |
| * radix. | |
| * @throws NumberFormatException If the {@code String} does not | |
| * contain a parsable {@code long}. | |
| */ | |
| public static Long valueOf(String s, int radix) throws NumberFormatException { | |
| return Long.valueOf(parseLong(s, radix)); | |
| } | |
| /** | |
| * Returns a {@code Long} object holding the value | |
| * of the specified {@code String}. The argument is | |
| * interpreted as representing a signed decimal {@code long}, | |
| * exactly as if the argument were given to the {@link | |
| * #parseLong(java.lang.String)} method. The result is a | |
| * {@code Long} object that represents the integer value | |
| * specified by the string. | |
| * | |
| * <p>In other words, this method returns a {@code Long} object | |
| * equal to the value of: | |
| * | |
| * <blockquote> | |
| * {@code Long.valueOf(Long.parseLong(s))} | |
| * </blockquote> | |
| * | |
| * @param s the string to be parsed. | |
| * @return a {@code Long} object holding the value | |
| * represented by the string argument. | |
| * @throws NumberFormatException If the string cannot be parsed | |
| * as a {@code long}. | |
| */ | |
| public static Long valueOf(String s) throws NumberFormatException | |
| { | |
| return Long.valueOf(parseLong(s, 10)); | |
| } | |
| private static final class LongCache { | |
| private LongCache() {} | |
| @Stable | |
| static final Long[] cache; | |
| static Long[] archivedCache; | |
| static { | |
| int size = -(-128) + 127 + 1; | |
| // Load and use the archived cache if it exists | |
| CDS.initializeFromArchive(LongCache.class); | |
| if (archivedCache == null) { | |
| Long[] c = new Long[size]; | |
| long value = -128; | |
| for(int i = 0; i < size; i++) { | |
| c[i] = new Long(value++); | |
| } | |
| archivedCache = c; | |
| } | |
| cache = archivedCache; | |
| assert cache.length == size; | |
| } | |
| } | |
| /** | |
| * Returns a {@code Long} instance representing the specified | |
| * {@code long} value. | |
| * If a new {@code Long} instance is not required, this method | |
| * should generally be used in preference to the constructor | |
| * {@link #Long(long)}, as this method is likely to yield | |
| * significantly better space and time performance by caching | |
| * frequently requested values. | |
| * | |
| * This method will always cache values in the range -128 to 127, | |
| * inclusive, and may cache other values outside of this range. | |
| * | |
| * @param l a long value. | |
| * @return a {@code Long} instance representing {@code l}. | |
| * @since 1.5 | |
| */ | |
| @IntrinsicCandidate | |
| public static Long valueOf(long l) { | |
| final int offset = 128; | |
| if (l >= -128 && l <= 127) { // will cache | |
| return LongCache.cache[(int)l + offset]; | |
| } | |
| return new Long(l); | |
| } | |
| /** | |
| * Decodes a {@code String} into a {@code Long}. | |
| * Accepts decimal, hexadecimal, and octal numbers given by the | |
| * following grammar: | |
| * | |
| * <blockquote> | |
| * <dl> | |
| * <dt><i>DecodableString:</i> | |
| * <dd><i>Sign<sub>opt</sub> DecimalNumeral</i> | |
| * <dd><i>Sign<sub>opt</sub></i> {@code 0x} <i>HexDigits</i> | |
| * <dd><i>Sign<sub>opt</sub></i> {@code 0X} <i>HexDigits</i> | |
| * <dd><i>Sign<sub>opt</sub></i> {@code #} <i>HexDigits</i> | |
| * <dd><i>Sign<sub>opt</sub></i> {@code 0} <i>OctalDigits</i> | |
| * | |
| * <dt><i>Sign:</i> | |
| * <dd>{@code -} | |
| * <dd>{@code +} | |
| * </dl> | |
| * </blockquote> | |
| * | |
| * <i>DecimalNumeral</i>, <i>HexDigits</i>, and <i>OctalDigits</i> | |
| * are as defined in section {@jls 3.10.1} of | |
| * <cite>The Java Language Specification</cite>, | |
| * except that underscores are not accepted between digits. | |
| * | |
| * <p>The sequence of characters following an optional | |
| * sign and/or radix specifier ("{@code 0x}", "{@code 0X}", | |
| * "{@code #}", or leading zero) is parsed as by the {@code | |
| * Long.parseLong} method with the indicated radix (10, 16, or 8). | |
| * This sequence of characters must represent a positive value or | |
| * a {@link NumberFormatException} will be thrown. The result is | |
| * negated if first character of the specified {@code String} is | |
| * the minus sign. No whitespace characters are permitted in the | |
| * {@code String}. | |
| * | |
| * @param nm the {@code String} to decode. | |
| * @return a {@code Long} object holding the {@code long} | |
| * value represented by {@code nm} | |
| * @throws NumberFormatException if the {@code String} does not | |
| * contain a parsable {@code long}. | |
| * @see java.lang.Long#parseLong(String, int) | |
| * @since 1.2 | |
| */ | |
| public static Long decode(String nm) throws NumberFormatException { | |
| int radix = 10; | |
| int index = 0; | |
| boolean negative = false; | |
| long result; | |
| if (nm.isEmpty()) | |
| throw new NumberFormatException("Zero length string"); | |
| char firstChar = nm.charAt(0); | |
| // Handle sign, if present | |
| if (firstChar == '-') { | |
| negative = true; | |
| index++; | |
| } else if (firstChar == '+') | |
| index++; | |
| // Handle radix specifier, if present | |
| if (nm.startsWith("0x", index) || nm.startsWith("0X", index)) { | |
| index += 2; | |
| radix = 16; | |
| } | |
| else if (nm.startsWith("#", index)) { | |
| index ++; | |
| radix = 16; | |
| } | |
| else if (nm.startsWith("0", index) && nm.length() > 1 + index) { | |
| index ++; | |
| radix = 8; | |
| } | |
| if (nm.startsWith("-", index) || nm.startsWith("+", index)) | |
| throw new NumberFormatException("Sign character in wrong position"); | |
| try { | |
| result = parseLong(nm, index, nm.length(), radix); | |
| result = negative ? -result : result; | |
| } catch (NumberFormatException e) { | |
| // If number is Long.MIN_VALUE, we'll end up here. The next line | |
| // handles this case, and causes any genuine format error to be | |
| // rethrown. | |
| String constant = negative ? ("-" + nm.substring(index)) | |
| : nm.substring(index); | |
| result = parseLong(constant, radix); | |
| } | |
| return result; | |
| } | |
| /** | |
| * The value of the {@code Long}. | |
| * | |
| * @serial | |
| */ | |
| private final long value; | |
| /** | |
| * Constructs a newly allocated {@code Long} object that | |
| * represents the specified {@code long} argument. | |
| * | |
| * @param value the value to be represented by the | |
| * {@code Long} object. | |
| * | |
| * @deprecated | |
| * It is rarely appropriate to use this constructor. The static factory | |
| * {@link #valueOf(long)} is generally a better choice, as it is | |
| * likely to yield significantly better space and time performance. | |
| */ | |
| @Deprecated(since="9") | |
| public Long(long value) { | |
| this.value = value; | |
| } | |
| /** | |
| * Constructs a newly allocated {@code Long} object that | |
| * represents the {@code long} value indicated by the | |
| * {@code String} parameter. The string is converted to a | |
| * {@code long} value in exactly the manner used by the | |
| * {@code parseLong} method for radix 10. | |
| * | |
| * @param s the {@code String} to be converted to a | |
| * {@code Long}. | |
| * @throws NumberFormatException if the {@code String} does not | |
| * contain a parsable {@code long}. | |
| * | |
| * @deprecated | |
| * It is rarely appropriate to use this constructor. | |
| * Use {@link #parseLong(String)} to convert a string to a | |
| * {@code long} primitive, or use {@link #valueOf(String)} | |
| * to convert a string to a {@code Long} object. | |
| */ | |
| @Deprecated(since="9") | |
| public Long(String s) throws NumberFormatException { | |
| this.value = parseLong(s, 10); | |
| } | |
| /** | |
| * Returns the value of this {@code Long} as a {@code byte} after | |
| * a narrowing primitive conversion. | |
| * @jls 5.1.3 Narrowing Primitive Conversion | |
| */ | |
| public byte byteValue() { | |
| return (byte)value; | |
| } | |
| /** | |
| * Returns the value of this {@code Long} as a {@code short} after | |
| * a narrowing primitive conversion. | |
| * @jls 5.1.3 Narrowing Primitive Conversion | |
| */ | |
| public short shortValue() { | |
| return (short)value; | |
| } | |
| /** | |
| * Returns the value of this {@code Long} as an {@code int} after | |
| * a narrowing primitive conversion. | |
| * @jls 5.1.3 Narrowing Primitive Conversion | |
| */ | |
| public int intValue() { | |
| return (int)value; | |
| } | |
| /** | |
| * Returns the value of this {@code Long} as a | |
| * {@code long} value. | |
| */ | |
| @IntrinsicCandidate | |
| public long longValue() { | |
| return value; | |
| } | |
| /** | |
| * Returns the value of this {@code Long} as a {@code float} after | |
| * a widening primitive conversion. | |
| * @jls 5.1.2 Widening Primitive Conversion | |
| */ | |
| public float floatValue() { | |
| return (float)value; | |
| } | |
| /** | |
| * Returns the value of this {@code Long} as a {@code double} | |
| * after a widening primitive conversion. | |
| * @jls 5.1.2 Widening Primitive Conversion | |
| */ | |
| public double doubleValue() { | |
| return (double)value; | |
| } | |
| /** | |
| * Returns a {@code String} object representing this | |
| * {@code Long}'s value. The value is converted to signed | |
| * decimal representation and returned as a string, exactly as if | |
| * the {@code long} value were given as an argument to the | |
| * {@link java.lang.Long#toString(long)} method. | |
| * | |
| * @return a string representation of the value of this object in | |
| * base 10. | |
| */ | |
| public String toString() { | |
| return toString(value); | |
| } | |
| /** | |
| * Returns a hash code for this {@code Long}. The result is | |
| * the exclusive OR of the two halves of the primitive | |
| * {@code long} value held by this {@code Long} | |
| * object. That is, the hashcode is the value of the expression: | |
| * | |
| * <blockquote> | |
| * {@code (int)(this.longValue()^(this.longValue()>>>32))} | |
| * </blockquote> | |
| * | |
| * @return a hash code value for this object. | |
| */ | |
| @Override | |
| public int hashCode() { | |
| return Long.hashCode(value); | |
| } | |
| /** | |
| * Returns a hash code for a {@code long} value; compatible with | |
| * {@code Long.hashCode()}. | |
| * | |
| * @param value the value to hash | |
| * @return a hash code value for a {@code long} value. | |
| * @since 1.8 | |
| */ | |
| public static int hashCode(long value) { | |
| return (int)(value ^ (value >>> 32)); | |
| } | |
| /** | |
| * Compares this object to the specified object. The result is | |
| * {@code true} if and only if the argument is not | |
| * {@code null} and is a {@code Long} object that | |
| * contains the same {@code long} value as this object. | |
| * | |
| * @param obj the object to compare with. | |
| * @return {@code true} if the objects are the same; | |
| * {@code false} otherwise. | |
| */ | |
| public boolean equals(Object obj) { | |
| if (obj instanceof Long ell) { | |
| return value == ell.longValue(); | |
| } | |
| return false; | |
| } | |
| /** | |
| * Determines the {@code long} value of the system property | |
| * with the specified name. | |
| * | |
| * <p>The first argument is treated as the name of a system | |
| * property. System properties are accessible through the {@link | |
| * java.lang.System#getProperty(java.lang.String)} method. The | |
| * string value of this property is then interpreted as a {@code | |
| * long} value using the grammar supported by {@link Long#decode decode} | |
| * and a {@code Long} object representing this value is returned. | |
| * | |
| * <p>If there is no property with the specified name, if the | |
| * specified name is empty or {@code null}, or if the property | |
| * does not have the correct numeric format, then {@code null} is | |
| * returned. | |
| * | |
| * <p>In other words, this method returns a {@code Long} object | |
| * equal to the value of: | |
| * | |
| * <blockquote> | |
| * {@code getLong(nm, null)} | |
| * </blockquote> | |
| * | |
| * @param nm property name. | |
| * @return the {@code Long} value of the property. | |
| * @see java.lang.System#getProperty(java.lang.String) | |
| * @see java.lang.System#getProperty(java.lang.String, java.lang.String) | |
| */ | |
| public static Long getLong(String nm) { | |
| return getLong(nm, null); | |
| } | |
| /** | |
| * Determines the {@code long} value of the system property | |
| * with the specified name. | |
| * | |
| * <p>The first argument is treated as the name of a system | |
| * property. System properties are accessible through the {@link | |
| * java.lang.System#getProperty(java.lang.String)} method. The | |
| * string value of this property is then interpreted as a {@code | |
| * long} value using the grammar supported by {@link Long#decode decode} | |
| * and a {@code Long} object representing this value is returned. | |
| * | |
| * <p>The second argument is the default value. A {@code Long} object | |
| * that represents the value of the second argument is returned if there | |
| * is no property of the specified name, if the property does not have | |
| * the correct numeric format, or if the specified name is empty or null. | |
| * | |
| * <p>In other words, this method returns a {@code Long} object equal | |
| * to the value of: | |
| * | |
| * <blockquote> | |
| * {@code getLong(nm, Long.valueOf(val))} | |
| * </blockquote> | |
| * | |
| * but in practice it may be implemented in a manner such as: | |
| * | |
| * <blockquote><pre> | |
| * Long result = getLong(nm, null); | |
| * return (result == null) ? Long.valueOf(val) : result; | |
| * </pre></blockquote> | |
| * | |
| * to avoid the unnecessary allocation of a {@code Long} object when | |
| * the default value is not needed. | |
| * | |
| * @param nm property name. | |
| * @param val default value. | |
| * @return the {@code Long} value of the property. | |
| * @see java.lang.System#getProperty(java.lang.String) | |
| * @see java.lang.System#getProperty(java.lang.String, java.lang.String) | |
| */ | |
| public static Long getLong(String nm, long val) { | |
| Long result = Long.getLong(nm, null); | |
| return (result == null) ? Long.valueOf(val) : result; | |
| } | |
| /** | |
| * Returns the {@code long} value of the system property with | |
| * the specified name. The first argument is treated as the name | |
| * of a system property. System properties are accessible through | |
| * the {@link java.lang.System#getProperty(java.lang.String)} | |
| * method. The string value of this property is then interpreted | |
| * as a {@code long} value, as per the | |
| * {@link Long#decode decode} method, and a {@code Long} object | |
| * representing this value is returned; in summary: | |
| * | |
| * <ul> | |
| * <li>If the property value begins with the two ASCII characters | |
| * {@code 0x} or the ASCII character {@code #}, not followed by | |
| * a minus sign, then the rest of it is parsed as a hexadecimal integer | |
| * exactly as for the method {@link #valueOf(java.lang.String, int)} | |
| * with radix 16. | |
| * <li>If the property value begins with the ASCII character | |
| * {@code 0} followed by another character, it is parsed as | |
| * an octal integer exactly as by the method {@link | |
| * #valueOf(java.lang.String, int)} with radix 8. | |
| * <li>Otherwise the property value is parsed as a decimal | |
| * integer exactly as by the method | |
| * {@link #valueOf(java.lang.String, int)} with radix 10. | |
| * </ul> | |
| * | |
| * <p>Note that, in every case, neither {@code L} | |
| * ({@code '\u005Cu004C'}) nor {@code l} | |
| * ({@code '\u005Cu006C'}) is permitted to appear at the end | |
| * of the property value as a type indicator, as would be | |
| * permitted in Java programming language source code. | |
| * | |
| * <p>The second argument is the default value. The default value is | |
| * returned if there is no property of the specified name, if the | |
| * property does not have the correct numeric format, or if the | |
| * specified name is empty or {@code null}. | |
| * | |
| * @param nm property name. | |
| * @param val default value. | |
| * @return the {@code Long} value of the property. | |
| * @see System#getProperty(java.lang.String) | |
| * @see System#getProperty(java.lang.String, java.lang.String) | |
| */ | |
| public static Long getLong(String nm, Long val) { | |
| String v = nm != null && !nm.isEmpty() ? System.getProperty(nm) : null; | |
| if (v != null) { | |
| try { | |
| return Long.decode(v); | |
| } catch (NumberFormatException e) { | |
| } | |
| } | |
| return val; | |
| } | |
| /** | |
| * Compares two {@code Long} objects numerically. | |
| * | |
| * @param anotherLong the {@code Long} to be compared. | |
| * @return the value {@code 0} if this {@code Long} is | |
| * equal to the argument {@code Long}; a value less than | |
| * {@code 0} if this {@code Long} is numerically less | |
| * than the argument {@code Long}; and a value greater | |
| * than {@code 0} if this {@code Long} is numerically | |
| * greater than the argument {@code Long} (signed | |
| * comparison). | |
| * @since 1.2 | |
| */ | |
| public int compareTo(Long anotherLong) { | |
| return compare(this.value, anotherLong.value); | |
| } | |
| /** | |
| * Compares two {@code long} values numerically. | |
| * The value returned is identical to what would be returned by: | |
| * <pre> | |
| * Long.valueOf(x).compareTo(Long.valueOf(y)) | |
| * </pre> | |
| * | |
| * @param x the first {@code long} to compare | |
| * @param y the second {@code long} to compare | |
| * @return the value {@code 0} if {@code x == y}; | |
| * a value less than {@code 0} if {@code x < y}; and | |
| * a value greater than {@code 0} if {@code x > y} | |
| * @since 1.7 | |
| */ | |
| public static int compare(long x, long y) { | |
| return (x < y) ? -1 : ((x == y) ? 0 : 1); | |
| } | |
| /** | |
| * Compares two {@code long} values numerically treating the values | |
| * as unsigned. | |
| * | |
| * @param x the first {@code long} to compare | |
| * @param y the second {@code long} to compare | |
| * @return the value {@code 0} if {@code x == y}; a value less | |
| * than {@code 0} if {@code x < y} as unsigned values; and | |
| * a value greater than {@code 0} if {@code x > y} as | |
| * unsigned values | |
| * @since 1.8 | |
| */ | |
| @IntrinsicCandidate | |
| public static int compareUnsigned(long x, long y) { | |
| return compare(x + MIN_VALUE, y + MIN_VALUE); | |
| } | |
| /** | |
| * Returns the unsigned quotient of dividing the first argument by | |
| * the second where each argument and the result is interpreted as | |
| * an unsigned value. | |
| * | |
| * <p>Note that in two's complement arithmetic, the three other | |
| * basic arithmetic operations of add, subtract, and multiply are | |
| * bit-wise identical if the two operands are regarded as both | |
| * being signed or both being unsigned. Therefore separate {@code | |
| * addUnsigned}, etc. methods are not provided. | |
| * | |
| * @param dividend the value to be divided | |
| * @param divisor the value doing the dividing | |
| * @return the unsigned quotient of the first argument divided by | |
| * the second argument | |
| * @see #remainderUnsigned | |
| * @since 1.8 | |
| */ | |
| @IntrinsicCandidate | |
| public static long divideUnsigned(long dividend, long divisor) { | |
| /* See Hacker's Delight (2nd ed), section 9.3 */ | |
| if (divisor >= 0) { | |
| final long q = (dividend >>> 1) / divisor << 1; | |
| final long r = dividend - q * divisor; | |
| return q + ((r | ~(r - divisor)) >>> (Long.SIZE - 1)); | |
| } | |
| return (dividend & ~(dividend - divisor)) >>> (Long.SIZE - 1); | |
| } | |
| /** | |
| * Returns the unsigned remainder from dividing the first argument | |
| * by the second where each argument and the result is interpreted | |
| * as an unsigned value. | |
| * | |
| * @param dividend the value to be divided | |
| * @param divisor the value doing the dividing | |
| * @return the unsigned remainder of the first argument divided by | |
| * the second argument | |
| * @see #divideUnsigned | |
| * @since 1.8 | |
| */ | |
| @IntrinsicCandidate | |
| public static long remainderUnsigned(long dividend, long divisor) { | |
| /* See Hacker's Delight (2nd ed), section 9.3 */ | |
| if (divisor >= 0) { | |
| final long q = (dividend >>> 1) / divisor << 1; | |
| final long r = dividend - q * divisor; | |
| /* | |
| * Here, 0 <= r < 2 * divisor | |
| * (1) When 0 <= r < divisor, the remainder is simply r. | |
| * (2) Otherwise the remainder is r - divisor. | |
| * | |
| * In case (1), r - divisor < 0. Applying ~ produces a long with | |
| * sign bit 0, so >> produces 0. The returned value is thus r. | |
| * | |
| * In case (2), a similar reasoning shows that >> produces -1, | |
| * so the returned value is r - divisor. | |
| */ | |
| return r - ((~(r - divisor) >> (Long.SIZE - 1)) & divisor); | |
| } | |
| /* | |
| * (1) When dividend >= 0, the remainder is dividend. | |
| * (2) Otherwise | |
| * (2.1) When dividend < divisor, the remainder is dividend. | |
| * (2.2) Otherwise the remainder is dividend - divisor | |
| * | |
| * A reasoning similar to the above shows that the returned value | |
| * is as expected. | |
| */ | |
| return dividend - (((dividend & ~(dividend - divisor)) >> (Long.SIZE - 1)) & divisor); | |
| } | |
| // Bit Twiddling | |
| /** | |
| * The number of bits used to represent a {@code long} value in two's | |
| * complement binary form. | |
| * | |
| * @since 1.5 | |
| */ | |
| @Native public static final int SIZE = 64; | |
| /** | |
| * The number of bytes used to represent a {@code long} value in two's | |
| * complement binary form. | |
| * | |
| * @since 1.8 | |
| */ | |
| public static final int BYTES = SIZE / Byte.SIZE; | |
| /** | |
| * Returns a {@code long} value with at most a single one-bit, in the | |
| * position of the highest-order ("leftmost") one-bit in the specified | |
| * {@code long} value. Returns zero if the specified value has no | |
| * one-bits in its two's complement binary representation, that is, if it | |
| * is equal to zero. | |
| * | |
| * @param i the value whose highest one bit is to be computed | |
| * @return a {@code long} value with a single one-bit, in the position | |
| * of the highest-order one-bit in the specified value, or zero if | |
| * the specified value is itself equal to zero. | |
| * @since 1.5 | |
| */ | |
| public static long highestOneBit(long i) { | |
| return i & (MIN_VALUE >>> numberOfLeadingZeros(i)); | |
| } | |
| /** | |
| * Returns a {@code long} value with at most a single one-bit, in the | |
| * position of the lowest-order ("rightmost") one-bit in the specified | |
| * {@code long} value. Returns zero if the specified value has no | |
| * one-bits in its two's complement binary representation, that is, if it | |
| * is equal to zero. | |
| * | |
| * @param i the value whose lowest one bit is to be computed | |
| * @return a {@code long} value with a single one-bit, in the position | |
| * of the lowest-order one-bit in the specified value, or zero if | |
| * the specified value is itself equal to zero. | |
| * @since 1.5 | |
| */ | |
| public static long lowestOneBit(long i) { | |
| // HD, Section 2-1 | |
| return i & -i; | |
| } | |
| /** | |
| * Returns the number of zero bits preceding the highest-order | |
| * ("leftmost") one-bit in the two's complement binary representation | |
| * of the specified {@code long} value. Returns 64 if the | |
| * specified value has no one-bits in its two's complement representation, | |
| * in other words if it is equal to zero. | |
| * | |
| * <p>Note that this method is closely related to the logarithm base 2. | |
| * For all positive {@code long} values x: | |
| * <ul> | |
| * <li>floor(log<sub>2</sub>(x)) = {@code 63 - numberOfLeadingZeros(x)} | |
| * <li>ceil(log<sub>2</sub>(x)) = {@code 64 - numberOfLeadingZeros(x - 1)} | |
| * </ul> | |
| * | |
| * @param i the value whose number of leading zeros is to be computed | |
| * @return the number of zero bits preceding the highest-order | |
| * ("leftmost") one-bit in the two's complement binary representation | |
| * of the specified {@code long} value, or 64 if the value | |
| * is equal to zero. | |
| * @since 1.5 | |
| */ | |
| @IntrinsicCandidate | |
| public static int numberOfLeadingZeros(long i) { | |
| int x = (int)(i >>> 32); | |
| return x == 0 ? 32 + Integer.numberOfLeadingZeros((int)i) | |
| : Integer.numberOfLeadingZeros(x); | |
| } | |
| /** | |
| * Returns the number of zero bits following the lowest-order ("rightmost") | |
| * one-bit in the two's complement binary representation of the specified | |
| * {@code long} value. Returns 64 if the specified value has no | |
| * one-bits in its two's complement representation, in other words if it is | |
| * equal to zero. | |
| * | |
| * @param i the value whose number of trailing zeros is to be computed | |
| * @return the number of zero bits following the lowest-order ("rightmost") | |
| * one-bit in the two's complement binary representation of the | |
| * specified {@code long} value, or 64 if the value is equal | |
| * to zero. | |
| * @since 1.5 | |
| */ | |
| @IntrinsicCandidate | |
| public static int numberOfTrailingZeros(long i) { | |
| int x = (int)i; | |
| return x == 0 ? 32 + Integer.numberOfTrailingZeros((int)(i >>> 32)) | |
| : Integer.numberOfTrailingZeros(x); | |
| } | |
| /** | |
| * Returns the number of one-bits in the two's complement binary | |
| * representation of the specified {@code long} value. This function is | |
| * sometimes referred to as the <i>population count</i>. | |
| * | |
| * @param i the value whose bits are to be counted | |
| * @return the number of one-bits in the two's complement binary | |
| * representation of the specified {@code long} value. | |
| * @since 1.5 | |
| */ | |
| @IntrinsicCandidate | |
| public static int bitCount(long i) { | |
| // HD, Figure 5-2 | |
| i = i - ((i >>> 1) & 0x5555555555555555L); | |
| i = (i & 0x3333333333333333L) + ((i >>> 2) & 0x3333333333333333L); | |
| i = (i + (i >>> 4)) & 0x0f0f0f0f0f0f0f0fL; | |
| i = i + (i >>> 8); | |
| i = i + (i >>> 16); | |
| i = i + (i >>> 32); | |
| return (int)i & 0x7f; | |
| } | |
| /** | |
| * Returns the value obtained by rotating the two's complement binary | |
| * representation of the specified {@code long} value left by the | |
| * specified number of bits. (Bits shifted out of the left hand, or | |
| * high-order, side reenter on the right, or low-order.) | |
| * | |
| * <p>Note that left rotation with a negative distance is equivalent to | |
| * right rotation: {@code rotateLeft(val, -distance) == rotateRight(val, | |
| * distance)}. Note also that rotation by any multiple of 64 is a | |
| * no-op, so all but the last six bits of the rotation distance can be | |
| * ignored, even if the distance is negative: {@code rotateLeft(val, | |
| * distance) == rotateLeft(val, distance & 0x3F)}. | |
| * | |
| * @param i the value whose bits are to be rotated left | |
| * @param distance the number of bit positions to rotate left | |
| * @return the value obtained by rotating the two's complement binary | |
| * representation of the specified {@code long} value left by the | |
| * specified number of bits. | |
| * @since 1.5 | |
| */ | |
| public static long rotateLeft(long i, int distance) { | |
| return (i << distance) | (i >>> -distance); | |
| } | |
| /** | |
| * Returns the value obtained by rotating the two's complement binary | |
| * representation of the specified {@code long} value right by the | |
| * specified number of bits. (Bits shifted out of the right hand, or | |
| * low-order, side reenter on the left, or high-order.) | |
| * | |
| * <p>Note that right rotation with a negative distance is equivalent to | |
| * left rotation: {@code rotateRight(val, -distance) == rotateLeft(val, | |
| * distance)}. Note also that rotation by any multiple of 64 is a | |
| * no-op, so all but the last six bits of the rotation distance can be | |
| * ignored, even if the distance is negative: {@code rotateRight(val, | |
| * distance) == rotateRight(val, distance & 0x3F)}. | |
| * | |
| * @param i the value whose bits are to be rotated right | |
| * @param distance the number of bit positions to rotate right | |
| * @return the value obtained by rotating the two's complement binary | |
| * representation of the specified {@code long} value right by the | |
| * specified number of bits. | |
| * @since 1.5 | |
| */ | |
| public static long rotateRight(long i, int distance) { | |
| return (i >>> distance) | (i << -distance); | |
| } | |
| /** | |
| * Returns the value obtained by reversing the order of the bits in the | |
| * two's complement binary representation of the specified {@code long} | |
| * value. | |
| * | |
| * @param i the value to be reversed | |
| * @return the value obtained by reversing order of the bits in the | |
| * specified {@code long} value. | |
| * @since 1.5 | |
| */ | |
| @IntrinsicCandidate | |
| public static long reverse(long i) { | |
| // HD, Figure 7-1 | |
| i = (i & 0x5555555555555555L) << 1 | (i >>> 1) & 0x5555555555555555L; | |
| i = (i & 0x3333333333333333L) << 2 | (i >>> 2) & 0x3333333333333333L; | |
| i = (i & 0x0f0f0f0f0f0f0f0fL) << 4 | (i >>> 4) & 0x0f0f0f0f0f0f0f0fL; | |
| return reverseBytes(i); | |
| } | |
| /** | |
| * Returns the value obtained by compressing the bits of the | |
| * specified {@code long} value, {@code i}, in accordance with | |
| * the specified bit mask. | |
| * <p> | |
| * For each one-bit value {@code mb} of the mask, from least | |
| * significant to most significant, the bit value of {@code i} at | |
| * the same bit location as {@code mb} is assigned to the compressed | |
| * value contiguously starting from the least significant bit location. | |
| * All the upper remaining bits of the compressed value are set | |
| * to zero. | |
| * | |
| * @apiNote | |
| * Consider the simple case of compressing the digits of a hexadecimal | |
| * value: | |
| * {@snippet lang="java" : | |
| * // Compressing drink to food | |
| * compress(0xCAFEBABEL, 0xFF00FFF0L) == 0xCABABL | |
| * } | |
| * Starting from the least significant hexadecimal digit at position 0 | |
| * from the right, the mask {@code 0xFF00FFF0} selects hexadecimal digits | |
| * at positions 1, 2, 3, 6 and 7 of {@code 0xCAFEBABE}. The selected digits | |
| * occur in the resulting compressed value contiguously from digit position | |
| * 0 in the same order. | |
| * <p> | |
| * The following identities all return {@code true} and are helpful to | |
| * understand the behaviour of {@code compress}: | |
| * {@snippet lang="java" : | |
| * // Returns 1 if the bit at position n is one | |
| * compress(x, 1L << n) == (x >> n & 1) | |
| * | |
| * // Logical shift right | |
| * compress(x, -1L << n) == x >>> n | |
| * | |
| * // Any bits not covered by the mask are ignored | |
| * compress(x, m) == compress(x & m, m) | |
| * | |
| * // Compressing a value by itself | |
| * compress(m, m) == (m == -1 || m == 0) ? m : (1L << bitCount(m)) - 1 | |
| * | |
| * // Expanding then compressing with the same mask | |
| * compress(expand(x, m), m) == x & compress(m, m) | |
| * } | |
| * <p> | |
| * The Sheep And Goats (SAG) operation (see Hacker's Delight, Second Edition, section 7.7) | |
| * can be implemented as follows: | |
| * {@snippet lang="java" : | |
| * long compressLeft(long i, long mask) { | |
| * // This implementation follows the description in Hacker's Delight which | |
| * // is informative. A more optimal implementation is: | |
| * // Long.compress(i, mask) << -Long.bitCount(mask) | |
| * return Long.reverse( | |
| * Long.compress(Long.reverse(i), Long.reverse(mask))); | |
| * } | |
| * | |
| * long sag(long i, long mask) { | |
| * return compressLeft(i, mask) | Long.compress(i, ~mask); | |
| * } | |
| * | |
| * // Separate the sheep from the goats | |
| * sag(0x00000000_CAFEBABEL, 0xFFFFFFFF_FF00FFF0L) == 0x00000000_CABABFEEL | |
| * } | |
| * | |
| * @param i the value whose bits are to be compressed | |
| * @param mask the bit mask | |
| * @return the compressed value | |
| * @see #expand | |
| * @since 19 | |
| */ | |
| @IntrinsicCandidate | |
| public static long compress(long i, long mask) { | |
| // See Hacker's Delight (2nd ed) section 7.4 Compress, or Generalized Extract | |
| i = i & mask; // Clear irrelevant bits | |
| long maskCount = ~mask << 1; // Count 0's to right | |
| for (int j = 0; j < 6; j++) { | |
| // Parallel prefix | |
| // Mask prefix identifies bits of the mask that have an odd number of 0's to the right | |
| long maskPrefix = parallelSuffix(maskCount); | |
| // Bits to move | |
| long maskMove = maskPrefix & mask; | |
| // Compress mask | |
| mask = (mask ^ maskMove) | (maskMove >>> (1 << j)); | |
| // Bits of i to be moved | |
| long t = i & maskMove; | |
| // Compress i | |
| i = (i ^ t) | (t >>> (1 << j)); | |
| // Adjust the mask count by identifying bits that have 0 to the right | |
| maskCount = maskCount & ~maskPrefix; | |
| } | |
| return i; | |
| } | |
| /** | |
| * Returns the value obtained by expanding the bits of the | |
| * specified {@code long} value, {@code i}, in accordance with | |
| * the specified bit mask. | |
| * <p> | |
| * For each one-bit value {@code mb} of the mask, from least | |
| * significant to most significant, the next contiguous bit value | |
| * of {@code i} starting at the least significant bit is assigned | |
| * to the expanded value at the same bit location as {@code mb}. | |
| * All other remaining bits of the expanded value are set to zero. | |
| * | |
| * @apiNote | |
| * Consider the simple case of expanding the digits of a hexadecimal | |
| * value: | |
| * {@snippet lang="java" : | |
| * expand(0x0000CABABL, 0xFF00FFF0L) == 0xCA00BAB0L | |
| * } | |
| * Starting from the least significant hexadecimal digit at position 0 | |
| * from the right, the mask {@code 0xFF00FFF0} selects the first five | |
| * hexadecimal digits of {@code 0x0000CABAB}. The selected digits occur | |
| * in the resulting expanded value in order at positions 1, 2, 3, 6, and 7. | |
| * <p> | |
| * The following identities all return {@code true} and are helpful to | |
| * understand the behaviour of {@code expand}: | |
| * {@snippet lang="java" : | |
| * // Logically shift right the bit at position 0 | |
| * expand(x, 1L << n) == (x & 1) << n | |
| * | |
| * // Logically shift right | |
| * expand(x, -1L << n) == x << n | |
| * | |
| * // Expanding all bits returns the mask | |
| * expand(-1L, m) == m | |
| * | |
| * // Any bits not covered by the mask are ignored | |
| * expand(x, m) == expand(x, m) & m | |
| * | |
| * // Compressing then expanding with the same mask | |
| * expand(compress(x, m), m) == x & m | |
| * } | |
| * <p> | |
| * The select operation for determining the position of the one-bit with | |
| * index {@code n} in a {@code long} value can be implemented as follows: | |
| * {@snippet lang="java" : | |
| * long select(long i, long n) { | |
| * // the one-bit in i (the mask) with index n | |
| * long nthBit = Long.expand(1L << n, i); | |
| * // the bit position of the one-bit with index n | |
| * return Long.numberOfTrailingZeros(nthBit); | |
| * } | |
| * | |
| * // The one-bit with index 0 is at bit position 1 | |
| * select(0b10101010_10101010, 0) == 1 | |
| * // The one-bit with index 3 is at bit position 7 | |
| * select(0b10101010_10101010, 3) == 7 | |
| * } | |
| * | |
| * @param i the value whose bits are to be expanded | |
| * @param mask the bit mask | |
| * @return the expanded value | |
| * @see #compress | |
| * @since 19 | |
| */ | |
| @IntrinsicCandidate | |
| public static long expand(long i, long mask) { | |
| // Save original mask | |
| long originalMask = mask; | |
| // Count 0's to right | |
| long maskCount = ~mask << 1; | |
| long maskPrefix = parallelSuffix(maskCount); | |
| // Bits to move | |
| long maskMove1 = maskPrefix & mask; | |
| // Compress mask | |
| mask = (mask ^ maskMove1) | (maskMove1 >>> (1 << 0)); | |
| maskCount = maskCount & ~maskPrefix; | |
| maskPrefix = parallelSuffix(maskCount); | |
| // Bits to move | |
| long maskMove2 = maskPrefix & mask; | |
| // Compress mask | |
| mask = (mask ^ maskMove2) | (maskMove2 >>> (1 << 1)); | |
| maskCount = maskCount & ~maskPrefix; | |
| maskPrefix = parallelSuffix(maskCount); | |
| // Bits to move | |
| long maskMove3 = maskPrefix & mask; | |
| // Compress mask | |
| mask = (mask ^ maskMove3) | (maskMove3 >>> (1 << 2)); | |
| maskCount = maskCount & ~maskPrefix; | |
| maskPrefix = parallelSuffix(maskCount); | |
| // Bits to move | |
| long maskMove4 = maskPrefix & mask; | |
| // Compress mask | |
| mask = (mask ^ maskMove4) | (maskMove4 >>> (1 << 3)); | |
| maskCount = maskCount & ~maskPrefix; | |
| maskPrefix = parallelSuffix(maskCount); | |
| // Bits to move | |
| long maskMove5 = maskPrefix & mask; | |
| // Compress mask | |
| mask = (mask ^ maskMove5) | (maskMove5 >>> (1 << 4)); | |
| maskCount = maskCount & ~maskPrefix; | |
| maskPrefix = parallelSuffix(maskCount); | |
| // Bits to move | |
| long maskMove6 = maskPrefix & mask; | |
| long t = i << (1 << 5); | |
| i = (i & ~maskMove6) | (t & maskMove6); | |
| t = i << (1 << 4); | |
| i = (i & ~maskMove5) | (t & maskMove5); | |
| t = i << (1 << 3); | |
| i = (i & ~maskMove4) | (t & maskMove4); | |
| t = i << (1 << 2); | |
| i = (i & ~maskMove3) | (t & maskMove3); | |
| t = i << (1 << 1); | |
| i = (i & ~maskMove2) | (t & maskMove2); | |
| t = i << (1 << 0); | |
| i = (i & ~maskMove1) | (t & maskMove1); | |
| // Clear irrelevant bits | |
| return i & originalMask; | |
| } | |
| @ForceInline | |
| private static long parallelSuffix(long maskCount) { | |
| long maskPrefix = maskCount ^ (maskCount << 1); | |
| maskPrefix = maskPrefix ^ (maskPrefix << 2); | |
| maskPrefix = maskPrefix ^ (maskPrefix << 4); | |
| maskPrefix = maskPrefix ^ (maskPrefix << 8); | |
| maskPrefix = maskPrefix ^ (maskPrefix << 16); | |
| maskPrefix = maskPrefix ^ (maskPrefix << 32); | |
| return maskPrefix; | |
| } | |
| /** | |
| * Returns the signum function of the specified {@code long} value. (The | |
| * return value is -1 if the specified value is negative; 0 if the | |
| * specified value is zero; and 1 if the specified value is positive.) | |
| * | |
| * @param i the value whose signum is to be computed | |
| * @return the signum function of the specified {@code long} value. | |
| * @since 1.5 | |
| */ | |
| public static int signum(long i) { | |
| // HD, Section 2-7 | |
| return (int) ((i >> 63) | (-i >>> 63)); | |
| } | |
| /** | |
| * Returns the value obtained by reversing the order of the bytes in the | |
| * two's complement representation of the specified {@code long} value. | |
| * | |
| * @param i the value whose bytes are to be reversed | |
| * @return the value obtained by reversing the bytes in the specified | |
| * {@code long} value. | |
| * @since 1.5 | |
| */ | |
| @IntrinsicCandidate | |
| public static long reverseBytes(long i) { | |
| i = (i & 0x00ff00ff00ff00ffL) << 8 | (i >>> 8) & 0x00ff00ff00ff00ffL; | |
| return (i << 48) | ((i & 0xffff0000L) << 16) | | |
| ((i >>> 16) & 0xffff0000L) | (i >>> 48); | |
| } | |
| /** | |
| * Adds two {@code long} values together as per the + operator. | |
| * | |
| * @param a the first operand | |
| * @param b the second operand | |
| * @return the sum of {@code a} and {@code b} | |
| * @see java.util.function.BinaryOperator | |
| * @since 1.8 | |
| */ | |
| public static long sum(long a, long b) { | |
| return a + b; | |
| } | |
| /** | |
| * Returns the greater of two {@code long} values | |
| * as if by calling {@link Math#max(long, long) Math.max}. | |
| * | |
| * @param a the first operand | |
| * @param b the second operand | |
| * @return the greater of {@code a} and {@code b} | |
| * @see java.util.function.BinaryOperator | |
| * @since 1.8 | |
| */ | |
| public static long max(long a, long b) { | |
| return Math.max(a, b); | |
| } | |
| /** | |
| * Returns the smaller of two {@code long} values | |
| * as if by calling {@link Math#min(long, long) Math.min}. | |
| * | |
| * @param a the first operand | |
| * @param b the second operand | |
| * @return the smaller of {@code a} and {@code b} | |
| * @see java.util.function.BinaryOperator | |
| * @since 1.8 | |
| */ | |
| public static long min(long a, long b) { | |
| return Math.min(a, b); | |
| } | |
| /** | |
| * Returns an {@link Optional} containing the nominal descriptor for this | |
| * instance, which is the instance itself. | |
| * | |
| * @return an {@link Optional} describing the {@linkplain Long} instance | |
| * @since 12 | |
| */ | |
| @Override | |
| public Optional<Long> describeConstable() { | |
| return Optional.of(this); | |
| } | |
| /** | |
| * Resolves this instance as a {@link ConstantDesc}, the result of which is | |
| * the instance itself. | |
| * | |
| * @param lookup ignored | |
| * @return the {@linkplain Long} instance | |
| * @since 12 | |
| */ | |
| @Override | |
| public Long resolveConstantDesc(MethodHandles.Lookup lookup) { | |
| return this; | |
| } | |
| /** use serialVersionUID from JDK 1.0.2 for interoperability */ | |
| @java.io.Serial | |
| @Native private static final long serialVersionUID = 4290774380558885855L; | |
| } |