Disruptor笔记(二)-测试

• 引入Hamcrest:是一个书写匹配器对象时允许直接定义匹配规则的框架.更丰富的表达方式，不侵入代码
• 使用Jmock来做Mock库
• 使用Junit4

 

工具类

Util工具类提供计算容量2的n次方的方法

        /**

    * Calculate the next power of 2, greater than or equal to x.<p>

    * From Hacker's Delight, Chapter 3, Harry S. Warren Jr.

    *

    * @param x Value to round up

    * @return The next power of 2 from x inclusive

    */

   public static int ceilingNextPowerOfTwo(final int x)

    {

       return 1 << (32 - Integer.numberOfLeadingZeros(x - 1));

    }

 

 

顺便学习一下Integer有趣的函数：

numberOfLeadingZeros

public static int numberOfLeadingZeros(int i)

Returns the numberof zero bits preceding the highest-order ("leftmost") one-bit in thetwo's complement binary representation of the specified int value. Returns 32 if the specified value has no one-bits in its two'scomplement representation, in other words if it is equal to zero.

Note that this method is closely related to the logarithmbase 2. For all positive int values x:

·        floor(log₂(x))= 31 -numberOfLeadingZeros(x)

·        ceil(log₂(x))= 32 -numberOfLeadingZeros(x - 1)

Returns:

the number of zerobits preceding the highest-order ("leftmost") one-bit in the two'scomplement binary representation of the specified int value, or 32 ifthe value is equal to zero.

Since:

1.5

numberOfTrailingZeros

public static int numberOfTrailingZeros(int i)

Returns the numberof zero bits following the lowest-order ("rightmost") one-bit in thetwo's complement binary representation of the specified int value. Returns 32 if the specified value has no one-bits in its two'scomplement representation, in other words if it is equal to zero.

Returns:

the number of zerobits following the lowest-order ("rightmost") one-bit in the two'scomplement binary representation of the specified int value, or 32 if thevalue is equal to zero.

Since:

1.5

bitCount

public static int bitCount(int i)

Returns the numberof one-bits in the two's complement binary representation of the specified int value. This function is sometimes referred to as thepopulation count.

Returns:

the number ofone-bits in the two's complement binary representation of the specified int value.

Since:

1.5