/*
* Copyright 2008 Google Inc.
*
* 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 java.lang;
/**
* Wraps a primitive <code>int</code> as an object.
*/
public final class Integer extends Number implements Comparable<Integer> {
public static final int MAX_VALUE = 0x7fffffff;
public static final int MIN_VALUE = 0x80000000;
public static final int SIZE = 32;
/**
* Use nested class to avoid clinit on outer.
*/
private static class BoxedValues {
// Box values according to JLS - between -128 and 127
private static Integer[] boxedValues = new Integer[256];
}
/**
* Use nested class to avoid clinit on outer.
*/
private static class ReverseNibbles {
/**
* A fast-lookup of the reversed bits of all the nibbles 0-15. Used to
* implement {@link #reverse(int)}.
*/
private static int[] reverseNibbles = {
0x0, 0x8, 0x4, 0xc, 0x2, 0xa, 0x6, 0xe, 0x1, 0x9, 0x5, 0xd, 0x3, 0xb,
0x7, 0xf};
}
public static int bitCount(int x) {
// Courtesy the University of Kentucky
// http://aggregate.org/MAGIC/#Population%20Count%20(Ones%20Count)
x -= ((x >> 1) & 0x55555555);
x = (((x >> 2) & 0x33333333) + (x & 0x33333333));
x = (((x >> 4) + x) & 0x0f0f0f0f);
x += (x >> 8);
x += (x >> 16);
return x & 0x0000003f;
}
public static Integer decode(String s) throws NumberFormatException {
return Integer.valueOf((int) __decodeAndValidateInt(s, MIN_VALUE, MAX_VALUE));
}
/**
* @skip
*
* Here for shared implementation with Arrays.hashCode
*/
public static int hashCode(int i) {
return i;
}
public static int highestOneBit(int i) {
if (i < 0) {
return MIN_VALUE;
} else if (i == 0) {
return 0;
} else {
int rtn;
for (rtn = 0x40000000; (rtn & i) == 0; rtn >>= 1) {
// loop down until matched
}
return rtn;
}
}
public static int lowestOneBit(int i) {
return i & -i;
}
public static int numberOfLeadingZeros(int i) {
// Based on Henry S. Warren, Jr: "Hacker's Delight", p. 80.
if (i < 0) {
return 0;
} else if (i == 0) {
return SIZE;
} else {
int y, m, n;
y = -(i >> 16);
m = (y >> 16) & 16;
n = 16 - m;
i = i >> m;
y = i - 0x100;
m = (y >> 16) & 8;
n += m;
i <<= m;
y = i - 0x1000;
m = (y >> 16) & 4;
n += m;
i <<= m;
y = i - 0x4000;
m = (y >> 16) & 2;
n += m;
i <<= m;
y = i >> 14;
m = y & ~(y >> 1);
return n + 2 - m;
}
}
public static int numberOfTrailingZeros(int i) {
if (i == 0) {
return SIZE;
} else {
int rtn = 0;
for (int r = 1; (r & i) == 0; r <<= 1) {
rtn++;
}
return rtn;
}
}
public static int parseInt(String s) throws NumberFormatException {
return parseInt(s, 10);
}
public static int parseInt(String s, int radix) throws NumberFormatException {
return __parseAndValidateInt(s, radix, MIN_VALUE, MAX_VALUE);
}
public static int reverse(int i) {
int[] nibbles = ReverseNibbles.reverseNibbles;
return (nibbles[i >>> 28]) | (nibbles[(i >> 24) & 0xf] << 4)
| (nibbles[(i >> 20) & 0xf] << 8) | (nibbles[(i >> 16) & 0xf] << 12)
| (nibbles[(i >> 12) & 0xf] << 16) | (nibbles[(i >> 8) & 0xf] << 20)
| (nibbles[(i >> 4) & 0xf] << 24) | (nibbles[i & 0xf] << 28);
}
public static int reverseBytes(int i) {
return ((i & 0xff) << 24) | ((i & 0xff00) << 8) | ((i & 0xff0000) >> 8)
| ((i & 0xff000000) >>> 24);
}
public static int rotateLeft(int i, int distance) {
while (distance-- > 0) {
i = i << 1 | ((i < 0) ? 1 : 0);
}
return i;
}
public static int rotateRight(int i, int distance) {
int ui = i & MAX_VALUE; // avoid sign extension
int carry = (i < 0) ? 0x40000000 : 0; // MIN_VALUE rightshifted 1
while (distance-- > 0) {
int nextcarry = ui & 1;
ui = carry | (ui >> 1);
carry = (nextcarry == 0) ? 0 : 0x40000000;
}
if (carry != 0) {
ui = ui | MIN_VALUE;
}
return ui;
}
public static int signum(int i) {
if (i == 0) {
return 0;
} else if (i < 0) {
return -1;
} else {
return 1;
}
}
public static String toBinaryString(int value) {
return toPowerOfTwoString(value, 1);
}
public static String toHexString(int value) {
return toPowerOfTwoString(value, 4);
}
public static String toOctalString(int value) {
return toPowerOfTwoString(value, 3);
}
public static String toString(int value) {
return String.valueOf(value);
}
public static String toString(int value, int radix) {
if (radix == 10 || radix < Character.MIN_RADIX || radix > Character.MAX_RADIX) {
return String.valueOf(value);
}
final int bufSize = 33;
char[] buf = new char[bufSize];
char[] digits = __Digits.digits;
int pos = bufSize - 1;
if (value >= 0) {
while (value >= radix) {
buf[pos--] = digits[value % radix];
value /= radix;
}
buf[pos] = digits[value];
} else {
while (value <= -radix) {
buf[pos--] = digits[-(value % radix)];
value /= radix;
}
buf[pos--] = digits[-value];
buf[pos] = '-';
}
return String.__valueOf(buf, pos, bufSize);
}
public static Integer valueOf(int i) {
if (i > -129 && i < 128) {
int rebase = i + 128;
Integer result = BoxedValues.boxedValues[rebase];
if (result == null) {
result = BoxedValues.boxedValues[rebase] = new Integer(i);
}
return result;
}
return new Integer(i);
}
public static Integer valueOf(String s) throws NumberFormatException {
return Integer.valueOf(Integer.parseInt(s));
}
public static Integer valueOf(String s, int radix)
throws NumberFormatException {
return Integer.valueOf(Integer.parseInt(s, radix));
}
private static String toPowerOfTwoString(int value, int shift) {
final int bufSize = 32 / shift;
int bitMask = (1 << shift) - 1;
char[] buf = new char[bufSize];
char[] digits = __Digits.digits;
int pos = bufSize - 1;
if (value >= 0) {
while (value > bitMask) {
buf[pos--] = digits[value & bitMask];
value >>= shift;
}
} else {
while (pos > 0) {
buf[pos--] = digits[value & bitMask];
value >>= shift;
}
}
buf[pos] = digits[value & bitMask];
return String.__valueOf(buf, pos, bufSize);
}
private final transient int value;
public Integer(int value) {
this.value = value;
}
public Integer(String s) {
value = parseInt(s);
}
@Override
public byte byteValue() {
return (byte) value;
}
public int compareTo(Integer b) {
if (value < b.value) {
return -1;
} else if (value > b.value) {
return 1;
} else {
return 0;
}
}
@Override
public double doubleValue() {
return value;
}
@Override
public boolean equals(Object o) {
return (o instanceof Integer) && (((Integer) o).value == value);
}
@Override
public float floatValue() {
return value;
}
@Override
public int hashCode() {
return hashCode(value);
}
@Override
public int intValue() {
return value;
}
@Override
public long longValue() {
return value;
}
@Override
public short shortValue() {
return (short) value;
}
@Override
public String toString() {
return toString(value);
}
}