eaglercraft-1.8/sources/main/java/com/google/common/primitives/UnsignedBytes.java

263 lines
8.4 KiB
Java
Raw Normal View History

2022-12-25 11:12:28 +02:00
/*
* Copyright (C) 2009 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;
/**
* Static utility methods pertaining to {@code byte} primitives that interpret
* values as <i>unsigned</i> (that is, any negative value {@code b} is treated
* as the positive value {@code 256 + b}). The corresponding methods that treat
* the values as signed are found in {@link SignedBytes}, and the methods for
* which signedness is not an issue are in {@link Bytes}.
*
* <p>
* See the Guava User Guide article on
* <a href= "http://code.google.com/p/guava-libraries/wiki/PrimitivesExplained">
* primitive utilities</a>.
*
* @author Kevin Bourrillion
* @author Martin Buchholz
* @author Hiroshi Yamauchi
* @author Louis Wasserman
* @since 1.0
*/
public final class UnsignedBytes {
private UnsignedBytes() {
}
/**
* The largest power of two that can be represented as an unsigned {@code
* byte}.
*
* @since 10.0
*/
public static final byte MAX_POWER_OF_TWO = (byte) 0x80;
/**
* The largest value that fits into an unsigned byte.
*
* @since 13.0
*/
public static final byte MAX_VALUE = (byte) 0xFF;
private static final int UNSIGNED_MASK = 0xFF;
/**
* Returns the value of the given byte as an integer, when treated as unsigned.
* That is, returns {@code value + 256} if {@code value} is negative;
* {@code value} itself otherwise.
*
* @since 6.0
*/
public static int toInt(byte value) {
return value & UNSIGNED_MASK;
}
/**
* Returns the {@code byte} value that, when treated as unsigned, is equal to
* {@code value}, if possible.
*
* @param value a value between 0 and 255 inclusive
* @return the {@code byte} value that, when treated as unsigned, equals
* {@code value}
* @throws IllegalArgumentException if {@code value} is negative or greater than
* 255
*/
public static byte checkedCast(long value) {
if ((value >> Byte.SIZE) != 0) {
// don't use checkArgument here, to avoid boxing
throw new IllegalArgumentException("Out of range: " + value);
}
return (byte) value;
}
/**
* Returns the {@code byte} value that, when treated as unsigned, is nearest in
* value to {@code value}.
*
* @param value any {@code long} value
* @return {@code (byte) 255} if {@code value >= 255}, {@code (byte) 0} if
* {@code value <= 0}, and {@code value} cast to {@code byte} otherwise
*/
public static byte saturatedCast(long value) {
if (value > toInt(MAX_VALUE)) {
return MAX_VALUE; // -1
}
if (value < 0) {
return (byte) 0;
}
return (byte) value;
}
/**
* Compares the two specified {@code byte} values, treating them as unsigned
* values between 0 and 255 inclusive. For example, {@code (byte) -127} is
* considered greater than {@code (byte) 127} because it is seen as having the
* value of positive {@code 129}.
*
* @param a the first {@code byte} to compare
* @param b the second {@code byte} to compare
* @return a negative value if {@code a} is less than {@code b}; a positive
* value if {@code a} is greater than {@code b}; or zero if they are
* equal
*/
public static int compare(byte a, byte b) {
return toInt(a) - toInt(b);
}
/**
* Returns the least value present in {@code array}.
*
* @param array a <i>nonempty</i> array of {@code byte} values
* @return the value present in {@code array} that is less than or equal to
* every other value in the array
* @throws IllegalArgumentException if {@code array} is empty
*/
public static byte min(byte... array) {
checkArgument(array.length > 0);
int min = toInt(array[0]);
for (int i = 1; i < array.length; i++) {
int next = toInt(array[i]);
if (next < min) {
min = next;
}
}
return (byte) min;
}
/**
* Returns the greatest value present in {@code array}.
*
* @param array a <i>nonempty</i> array of {@code byte} values
* @return the value present in {@code array} that is greater than or equal to
* every other value in the array
* @throws IllegalArgumentException if {@code array} is empty
*/
public static byte max(byte... array) {
checkArgument(array.length > 0);
int max = toInt(array[0]);
for (int i = 1; i < array.length; i++) {
int next = toInt(array[i]);
if (next > max) {
max = next;
}
}
return (byte) max;
}
/**
* Returns a string representation of x, where x is treated as unsigned.
*
* @since 13.0
*/
@Beta
public static String toString(byte x) {
return toString(x, 10);
}
/**
* Returns a string representation of {@code x} for the given radix, where
* {@code x} is treated as unsigned.
*
* @param x the value to convert to a string.
* @param radix the radix to use while working with {@code x}
* @throws IllegalArgumentException if {@code radix} is not between
* {@link Character#MIN_RADIX} and
* {@link Character#MAX_RADIX}.
* @since 13.0
*/
@Beta
public static String toString(byte x, int radix) {
checkArgument(radix >= Character.MIN_RADIX && radix <= Character.MAX_RADIX,
"radix (%s) must be between Character.MIN_RADIX and Character.MAX_RADIX", radix);
// Benchmarks indicate this is probably not worth optimizing.
return Integer.toString(toInt(x), radix);
}
/**
* Returns the unsigned {@code byte} value represented by the given decimal
* string.
*
* @throws NumberFormatException if the string does not contain a valid unsigned
* {@code byte} value
* @throws NullPointerException if {@code s} is null (in contrast to
* {@link Byte#parseByte(String)})
* @since 13.0
*/
@Beta
public static byte parseUnsignedByte(String string) {
return parseUnsignedByte(string, 10);
}
/**
* Returns the unsigned {@code byte} value represented by a string with the
* given radix.
*
* @param string the string containing the unsigned {@code byte} representation
* to be parsed.
* @param radix the radix to use while parsing {@code string}
* @throws NumberFormatException if the string does not contain a valid unsigned
* {@code byte} with the given radix, or if
* {@code radix} is not between
* {@link Character#MIN_RADIX} and
* {@link Character#MAX_RADIX}.
* @throws NullPointerException if {@code s} is null (in contrast to
* {@link Byte#parseByte(String)})
* @since 13.0
*/
@Beta
public static byte parseUnsignedByte(String string, int radix) {
int parse = Integer.parseInt(checkNotNull(string), radix);
// We need to throw a NumberFormatException, so we have to duplicate
// checkedCast. =(
if (parse >> Byte.SIZE == 0) {
return (byte) parse;
} else {
throw new NumberFormatException("out of range: " + parse);
}
}
/**
* Returns a string containing the supplied {@code byte} values separated by
* {@code separator}. For example, {@code join(":", (byte) 1, (byte) 2,
* (byte) 255)} returns the string {@code "1:2:255"}.
*
* @param separator the text that should appear between consecutive values in
* the resulting string (but not at the start or end)
* @param array an array of {@code byte} values, possibly empty
*/
public static String join(String separator, byte... array) {
checkNotNull(separator);
if (array.length == 0) {
return "";
}
// For pre-sizing a builder, just get the right order of magnitude
StringBuilder builder = new StringBuilder(array.length * (3 + separator.length()));
builder.append(toInt(array[0]));
for (int i = 1; i < array.length; i++) {
builder.append(separator).append(toString(array[i]));
}
return builder.toString();
}
}