Java代码性能评估库Stalker介绍

English Document

这是一个简单的用来对Java代码做性能评估的工具库。

特性

• 轻量级（jar包仅26kb）
• API简单易用
• 易于集成或扩展

Maven集成

<dependency>
    <groupId>com.zxd</groupId>
    <artifactId>stalker</artifactId>
    <version>1.0.0</version>
</dependency>

API 介绍和使用

预先准备

在对Java方法做性能测试之前，先准备好待测试的类和方法：

/**
 * 用于测量（仅测试使用）该类中的方法的执行耗时的类.
 *
 * @author zhangxianda on 2019-02-03.
 */
public class MyTestService {

<span class="token keyword">private</span> <span class="token keyword">static</span> <span class="token keyword">final</span> <span class="token class-name">Logger</span> log <span class="token operator">=</span> <span class="token class-name">LoggerFactory</span><span class="token punctuation">.</span><span class="token function">getLogger</span><span class="token punctuation">(</span><span class="token class-name">MyTestService</span><span class="token punctuation">.</span><span class="token keyword">class</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">/**
 * 测试方法1，模拟业务代码耗时 2~5 ms，且会有约 1% 的几率执行异常.
 */</span>
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">hello</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">&#123;</span>
    <span class="token comment">// 模拟运行时抛出异常.</span>
    <span class="token keyword">if</span> <span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">Random</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">nextInt</span><span class="token punctuation">(</span><span class="token number">100</span><span class="token punctuation">)</span> <span class="token operator">==</span> <span class="token number">5</span><span class="token punctuation">)</span> <span class="token punctuation">&#123;</span>
        <span class="token keyword">throw</span> <span class="token keyword">new</span> <span class="token class-name">MyServiceException</span><span class="token punctuation">(</span><span class="token string">"My Service Exception."</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token punctuation">&#125;</span>

    <span class="token comment">// 模拟运行占用约 2~5 ms 的时间.</span>
    <span class="token keyword">this</span><span class="token punctuation">.</span><span class="token function">sleep</span><span class="token punctuation">(</span><span class="token number">2L</span> <span class="token operator">+</span> <span class="token keyword">new</span> <span class="token class-name">Random</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">nextInt</span><span class="token punctuation">(</span><span class="token number">3</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">&#125;</span>

<span class="token comment">/**
 * 测试方法2，模拟业务代码运行占用约 2 ms 的时间.
 */</span>
<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">fastHello</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">&#123;</span>
    <span class="token keyword">this</span><span class="token punctuation">.</span><span class="token function">sleep</span><span class="token punctuation">(</span><span class="token number">2L</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">&#125;</span>

<span class="token comment">/**
 * 本线程调用该方法时，睡眠指定时间，用来模拟业务耗时.
 *
 * @param time 时间
 */</span>
<span class="token keyword">private</span> <span class="token keyword">void</span> <span class="token function">sleep</span><span class="token punctuation">(</span><span class="token keyword">long</span> time<span class="token punctuation">)</span> <span class="token punctuation">&#123;</span>
    <span class="token keyword">try</span> <span class="token punctuation">&#123;</span>
        <span class="token class-name">Thread</span><span class="token punctuation">.</span><span class="token function">sleep</span><span class="token punctuation">(</span>time<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token punctuation">&#125;</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">InterruptedException</span> e<span class="token punctuation">)</span> <span class="token punctuation">&#123;</span>
        log<span class="token punctuation">.</span><span class="token function">info</span><span class="token punctuation">(</span><span class="token string">"InterruptedException"</span><span class="token punctuation">,</span> e<span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token class-name">Thread</span><span class="token punctuation">.</span><span class="token function">currentThread</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">interrupt</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token punctuation">&#125;</span>
<span class="token punctuation">&#125;</span>

}

Stalker类

1. 最简示例

以下代码将会预热5次，然后在单线程下正式执行10次，从而将运行结果计算统计并输出出来：

public static void main(String[] args) {
    Stalker.run(() -> new MyTestService().hello());
}

以上结果将默认在控制台输出：

+-----------------------------------------------------------------------------------------------------------------------------------------+
|                                  threads: 1, concurrens: 1, warmups:5, runs: 10, printErrorLog: false                                   |
+---+----------+-------+---------+---------+----------+---------+---------+---------+---------+---------------------+---------------------+
|   |  Costs   | Total | Success | Failure |   Sum    |   Avg   |   Min   |   Max   | StdDev  | 95% LowerConfidence | 95% UpperConfidence |
+---+----------+-------+---------+---------+----------+---------+---------+---------+---------+---------------------+---------------------+
| 1 | 35.33 ms |  10   |   10    |    0    | 35.29 ms | 3.53 ms | 2.56 ms | 4.81 ms | 0.85 ms |       3.0 ms        |       4.06 ms       |
+---+----------+-------+---------+---------+----------+---------+---------+---------+---------+---------------------+---------------------+

2. 更全示例

以下代码表示，两个方法hello()和fastHello()将会预热1000次，在1000个线程200个并发下，每次执行10次：

Stalker.run(Options.of(1000, 200).warmups(1000).runs(10),
        () -> new MyTestService().hello(),
        () -> new MyTestService().fastHello());

以上结果将默认在控制台输出：

+------------------------------------------------------------------------------------------------------------------------------------------+
|                               threads: 1000, concurrens: 200, warmups:1000, runs: 10, printErrorLog: false                               |
+---+-----------+-------+---------+---------+---------+---------+---------+----------+---------+---------------------+---------------------+
|   |   Costs   | Total | Success | Failure |   Sum   |   Avg   |   Min   |   Max    | StdDev  | 95% LowerConfidence | 95% UpperConfidence |
+---+-----------+-------+---------+---------+---------+---------+---------+----------+---------+---------------------+---------------------+
| 1 | 454.33 ms | 10000 |  9900   |   100   | 36.79 s | 3.72 ms | 2.01 ms | 11.89 ms | 1.31 ms |       3.69 ms       |       3.74 ms       |
| 2 | 159.94 ms | 10000 |  10000  |    0    | 21.72 s | 2.17 ms | 2.01 ms | 3.24 ms  | 0.15 ms |       2.17 ms       |       2.18 ms       |
+---+-----------+-------+---------+---------+---------+---------+---------+----------+---------+---------------------+---------------------+

结果说明：

• Costs: 实际正式运行所消耗的总时间
• Total: 正式运行的总次数
• Success: 正式运行的成功次数
• Failure: 正式运行的失败次数
• Sum: 每次运行的耗时结果求和之后的值
• Avg: 所有运行耗时结果的算术平均数
• Min: 所有运行耗时结果中最小值
• Max: 所有运行耗时结果中最大值
• StdDev: 所有运行耗时结果的标准方差
• 95% LowerConfidence: 95%置信区间的最小边界值
• 95% LowerConfidence: 95%置信区间的最大边界值

3. 主要方法

• void run(Runnable... runnables): 对若干个要执行的代码做性能测量评估.
• void run(Options options, Runnable... runnables): 通过自定义的Options对若干个要执行的代码做性能测量评估.

Options类

Options表示做性能测量时的选项参数

主要属性如下

• name: 选项参数的名称
• threads: 正式执行的线程数，默认为1。
• concurrens: 正式多线程下执行的并发数，默认为1。
• warmups: 单线程下的预热次数，默认5。
• runs: 每个线程正式执行的次数，默认10。
• printErrorLog: 是否打印错误日志，默认false。
• outputs: 将测量结果通过多种方式(集合)输出出来，默认为输出到控制台，可自定义实现MeasureOutput接口。

主要方法

以下是构造Options实例的若干重载方法：

• Options of(String name)
• Options of(int runs)
• Options of(String name, int runs)
• Options of(int threads, int concurrens)
• Options of(String name, int threads, int concurrens)
• Options of(String name, int threads, int concurrens, int runs)

其他方法：

• boolean valid(): 校验Options相关参数是否合法
• Options named(String name): 设置 Options 实例的 name 属性
• Options threads(int threads): 设置 Options 实例的 threads 属性
• Options concurrens(int concurrens): 设置 Options 实例的 concurrens 属性
• Options warmups(int warmups): 设置 Options 实例的 warmups 属性
• Options runs(int runs): 设置 Options 实例的 runs 属性
• Options printErrorLog(boolean printErrorLog): 设置 Options 实例的 printErrorLog 属性
• Options outputs(MeasureOutput... measureOutputs): 自定义设置 Options 实例的 MeasureOutput 输出通道

Assert类

Assert类主要用来做断言使用。

示例

Assert.assertFaster(Options.of(),
        () -> new MyTestService().fastHello(),
        () -> new MyTestService().hello());

许可证

本 stalker 类库遵守 Apache License 2.0 许可证。