com.gettyio.core.util

类 MathUtil

java.lang.Object

com.gettyio.core.util.MathUtil

public final class MathUtil
extends Object

Math utility methods.

方法概要

限定符和类型	方法和说明
static int	compare(int x, int y) Compares two int values.
static int	compare(long x, long y) Compare two long values.
static int	findNextPositivePowerOfTwo(int value) Fast method of finding the next power of 2 greater than or equal to the supplied value.
static boolean	isOutOfBounds(int index, int length, int capacity) 确定请求的{索引}和{长度}是否适合{容量} Determine if the requested index and length will fit within capacity.
static int	safeFindNextPositivePowerOfTwo(int value) 求2的下一个幂值大于或等于提供值的快速方法。

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

方法详细资料

findNextPositivePowerOfTwo

public static int findNextPositivePowerOfTwo(int value)

Fast method of finding the next power of 2 greater than or equal to the supplied value. 求大于或等于2的下一个幂的快速方法

If the value is <= 0 then 1 will be returned. This method is not suitable for Integer.MIN_VALUE or numbers greater than 2^30. 如果值是<= 0，则返回1。 此方法不适合Integer.MIN_VALUE或大于2^30的数字

参数:

value - from which to search for next power of 2

返回:

The next power of 2 or the value itself if it is a power of 2

safeFindNextPositivePowerOfTwo

public static int safeFindNextPositivePowerOfTwo(int value)

求2的下一个幂值大于或等于提供值的快速方法。 Fast method of finding the next power of 2 greater than or equal to the supplied value.

This method will do runtime bounds checking and call findNextPositivePowerOfTwo(int) if within a valid range.

参数:

value - from which to search for next power of 2

返回:

The next power of 2 or the value itself if it is a power of 2.

Special cases for return values are as follows:

• <= 0 -> 1
• >= 2^30 -> 2^30

isOutOfBounds

public static boolean isOutOfBounds(int index,
                                    int length,
                                    int capacity)

确定请求的{索引}和{长度}是否适合{容量} Determine if the requested index and length will fit within capacity.

参数:

index - The starting index.

length - The length which will be utilized (starting from index).

capacity - The capacity that index + length is allowed to be within.

返回:

true if the requested index and length will fit within capacity. false if this would result in an index out of bounds exception.

compare

public static int compare(int x,
                          int y)

Compares two int values. 比较两个值

参数:

x - the first int to compare

y - the second int to compare

返回:

the value 0 if x == y; -1 if x < y; and 1 if x > y

compare

public static int compare(long x,
                          long y)

Compare two long values.

参数:

x - the first long to compare.

y - the second long to compare.

返回:

• 0 if x == y
• > 0 if x > y
• < 0 if x < y