jnr.ffi.NativeLong Maven / Gradle / Ivy
/*
* Copyright (C) 2008-2010 Wayne Meissner
*
* This file is part of the JNR project.
*
* 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 jnr.ffi;
/**
* Represents a C long.
*
* In C, a long can be either 32 bits or 64bits, depending on the platform.
*
* Replace any function parameters which are long in the C definition with
* a NativeLong.
*/
public final class NativeLong extends Number implements Comparable {
private static final long serialVersionUID = 1L;
private static final NativeLong ZERO = new NativeLong(0);
private static final NativeLong ONE = new NativeLong(1);
private static final NativeLong MINUS_ONE = new NativeLong(-1);
private final long value;
/**
* Creates a new NativeLong instance with the supplied value.
*
* @param value a long or integer.
*/
public NativeLong(long value) {
this.value = value;
}
/**
* Creates a new NativeLong instance with the supplied value.
*
* @param value an integer.
*/
public NativeLong(int value) {
this.value = value;
}
/**
* Returns an integer representation of this NativeLong.
*
* @return an integer value for this NativeLong.
*/
@Override
public final int intValue() {
return (int) value;
}
/**
* Returns an {@code long} representation of this NativeLong.
*
* @return an {@code long} value for this NativeLong.
*/
@Override
public final long longValue() {
return value;
}
/**
* Returns an {@code float} representation of this NativeLong.
*
* @return an {@code float} value for this NativeLong.
*/
@Override
public final float floatValue() {
return (float) value;
}
/**
* Returns an {@code double} representation of this NativeLong.
*
* @return an {@code double} value for this NativeLong.
*/
@Override
public final double doubleValue() {
return (double) value;
}
/**
* Gets a hash code for this {@code NativeLong}.
*
* @return a hash code for this {@code NativeLong}.
*/
@Override
public final int hashCode() {
return (int)(value ^ (value >>> 32));
}
/**
* Compares this NativeLong to another NativeLong.
*
* @param obj the other NativeLong to compare to.
* @return {@code true} if this NativeLong is equal to the other
* NativeLong, else false.
*/
@Override
public final boolean equals(Object obj) {
return ((obj instanceof NativeLong) && value == ((NativeLong) obj).value);
}
/**
* Returns a string representation of this NativeLong.
*
* @return a string representation of this NativeLong.
*/
@Override
public String toString() {
return String.valueOf(value);
}
/**
* Compares two {@code NativeLong} instances numerically.
*
* @param other the other NativeLong to compare to.
*
* @return {@code 0} if {@code other} is equal to this instance, -1 if this
* instance is numerically less than {@code other} or 1 if this instance is
* numerically greater than {@code other}.
*/
public final int compareTo(NativeLong other) {
return value < other.value ? -1 : value > other.value ? 1 : 0;
}
/**
* Internal cache of common native long values
*/
private static final class Cache {
private Cache() {}
static final NativeLong[] cache = new NativeLong[256];
static {
for (int i = 0; i < cache.length; ++i) {
cache[i] = new NativeLong(i - 128);
}
cache[128 + 0] = ZERO;
cache[128 + 1] = ONE;
cache[128 - 1] = MINUS_ONE;
}
}
private static NativeLong _valueOf(final long value) {
return value >= -128 && value <= 127
? Cache.cache[128 + (int) value] : new NativeLong(value);
}
private static NativeLong _valueOf(final int value) {
return value >= -128 && value <= 127
? Cache.cache[128 + value] : new NativeLong(value);
}
/**
* Returns a NativeLong instance representing the specified long value
*
* @param value a long value
* @return a NativeLong instance representing value
*/
public static NativeLong valueOf(final long value) {
return value == 0 ? ZERO : value == 1 ? ONE : value == -1 ? MINUS_ONE : _valueOf(value);
}
/**
* Returns a NativeLong instance representing the specified int value
*
* @param value a 32bit integer value
* @return a NativeLong instance representing value
*/
public static NativeLong valueOf(final int value) {
return value == 0 ? ZERO : value == 1 ? ONE : value == -1 ? MINUS_ONE : _valueOf(value);
}
}