/*
* Copyright (C) 2011 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
* in compliance with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the
* License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied. See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.primitives;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import java.io.Serializable;
import java.math.BigInteger;
import javax.annotation.Nullable;
/**
* A wrapper class for unsigned {@code long} values, supporting arithmetic operations.
*
* <p>In some cases, when speed is more important than code readability, it may be faster simply to
* treat primitive {@code long} values as unsigned, using the methods from {@link UnsignedLongs}.
*
* <p>See the Guava User Guide article on <a href=
* "http://code.google.com/p/guava-libraries/wiki/PrimitivesExplained#Unsigned_support">
* unsigned primitive utilities</a>.
*
* @author Louis Wasserman
* @author Colin Evans
* @since 11.0
*/
@Beta
@GwtCompatible(serializable = true)
public final class UnsignedLong extends Number implements Comparable<UnsignedLong>, Serializable {
private static final long UNSIGNED_MASK = 0x7fffffffffffffffL;
public static final UnsignedLong ZERO = new UnsignedLong(0);
public static final UnsignedLong ONE = new UnsignedLong(1);
public static final UnsignedLong MAX_VALUE = new UnsignedLong(-1L);
private final long value;
private UnsignedLong(long value) {
this.value = value;
}
/**
* Returns an {@code UnsignedLong} that, when treated as signed, is equal to {@code value}. The
* inverse operation is {@link #longValue()}.
*
* <p>Put another way, if {@code value} is negative, the returned result will be equal to
* {@code 2^64 + value}; otherwise, the returned result will be equal to {@code value}.
*/
public static UnsignedLong asUnsigned(long value) {
return new UnsignedLong(value);
}
/**
* Returns a {@code UnsignedLong} representing the same value as the specified {@code BigInteger}
* . This is the inverse operation of {@link #bigIntegerValue()}.
*
* @throws IllegalArgumentException if {@code value} is negative or {@code value >= 2^64}
*/
public static UnsignedLong valueOf(BigInteger value) {
checkNotNull(value);
checkArgument(value.signum() >= 0 && value.bitLength() <= Long.SIZE,
"value (%s) is outside the range for an unsigned long value", value);
return asUnsigned(value.longValue());
}
/**
* Returns an {@code UnsignedLong} holding the value of the specified {@code String}, parsed as
* an unsigned {@code long} value.
*
* @throws NumberFormatException if the string does not contain a parsable unsigned {@code long}
* value
*/
public static UnsignedLong valueOf(String string) {
return valueOf(string, 10);
}
/**
* Returns an {@code UnsignedLong} holding the value of the specified {@code String}, parsed as
* an unsigned {@code long} value in the specified radix.
*
* @throws NumberFormatException if the string does not contain a parsable unsigned {@code long}
* value, or {@code radix} is not between {@link Character#MIN_RADIX} and
* {@link Character#MAX_RADIX}
*/
public static UnsignedLong valueOf(String string, int radix) {
return asUnsigned(UnsignedLongs.parseUnsignedLong(string, radix));
}
/**
* Returns the result of adding this and {@code val}. If the result would have more than 64 bits,
* returns the low 64 bits of the result.
*/
public UnsignedLong add(UnsignedLong val) {
checkNotNull(val);
return asUnsigned(this.value + val.value);
}
/**
* Returns the result of subtracting this and {@code val}. If the result would be negative,
* returns the low 64 bits of the result.
*/
public UnsignedLong subtract(UnsignedLong val) {
checkNotNull(val);
return asUnsigned(this.value - val.value);
}
/**
* Returns the result of multiplying this and {@code val}. If the result would have more than 64
* bits, returns the low 64 bits of the result.
*/
public UnsignedLong multiply(UnsignedLong val) {
checkNotNull(val);
return asUnsigned(value * val.value);
}
/**
* Returns the result of dividing this by {@code val}.
*/
public UnsignedLong divide(UnsignedLong val) {
checkNotNull(val);
return asUnsigned(UnsignedLongs.divide(value, val.value));
}
/**
* Returns the remainder of dividing this by {@code val}.
*/
public UnsignedLong remainder(UnsignedLong val) {
checkNotNull(val);
return asUnsigned(UnsignedLongs.remainder(value, val.value));
}
/**
* Returns the value of this {@code UnsignedLong} as an {@code int}.
*/
@Override
public int intValue() {
return (int) value;
}
/**
* Returns the value of this {@code UnsignedLong} as a {@code long}. This is an inverse operation
* to {@link #asUnsigned}.
*
* <p>Note that if this {@code UnsignedLong} holds a value {@code >= 2^63}, the returned value
* will be equal to {@code this - 2^64}.
*/
@Override
public long longValue() {
return value;
}
/**
* Returns the value of this {@code UnsignedLong} as a {@code float}, analogous to a widening
* primitive conversion from {@code long} to {@code float}, and correctly rounded.
*/
@Override
public float floatValue() {
@SuppressWarnings("cast")
float fValue = (float) (value & UNSIGNED_MASK);
if (value < 0) {
fValue += 0x1.0p63f;
}
return fValue;
}
/**
* Returns the value of this {@code UnsignedLong} as a {@code double}, analogous to a widening
* primitive conversion from {@code long} to {@code double}, and correctly rounded.
*/
@Override
public double doubleValue() {
@SuppressWarnings("cast")
double dValue = (double) (value & UNSIGNED_MASK);
if (value < 0) {
dValue += 0x1.0p63;
}
return dValue;
}
/**
* Returns the value of this {@code UnsignedLong} as a {@link BigInteger}.
*/
public BigInteger bigIntegerValue() {
BigInteger bigInt = BigInteger.valueOf(value & UNSIGNED_MASK);
if (value < 0) {
bigInt = bigInt.setBit(Long.SIZE - 1);
}
return bigInt;
}
@Override
public int compareTo(UnsignedLong o) {
checkNotNull(o);
return UnsignedLongs.compare(value, o.value);
}
@Override
public int hashCode() {
return Longs.hashCode(value);
}
@Override
public boolean equals(@Nullable Object obj) {
if (obj instanceof UnsignedLong) {
UnsignedLong other = (UnsignedLong) obj;
return value == other.value;
}
return false;
}
/**
* Returns a string representation of the {@code UnsignedLong} value, in base 10.
*/
@Override
public String toString() {
return UnsignedLongs.toString(value);
}
/**
* Returns a string representation of the {@code UnsignedLong} value, in base {@code radix}. If
* {@code radix < Character.MIN_RADIX} or {@code radix > Character.MAX_RADIX}, the radix
* {@code 10} is used.
*/
public String toString(int radix) {
return UnsignedLongs.toString(value, radix);
}
}