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Testing Event Bus Performance Optimization in AndroidUtilCode

This test suite provides a comprehensive performance comparison between BusUtils and EventBus implementations in Android. It evaluates registration, posting, and unregistration operations through systematic benchmarking tests with multiple iterations and varying subscriber counts.

Test Coverage Overview

The test suite covers extensive performance benchmarking between BusUtils and EventBus libraries.

Key areas tested include:

Registration performance with 10,000 subscribers
Message posting performance with single and multiple subscribers
Unregistration performance with 10,000 subscribers
Comparative timing analysis across multiple iterations

Implementation Analysis

The testing approach employs systematic benchmarking methodology using JUnit framework.

Technical implementation features:

Custom CompareCallback interface for standardized testing
Reflection-based setup for BusUtils registration
Averaged performance metrics across multiple samples
Controlled test environment with proper setup and teardown

Technical Details

Testing infrastructure includes:

JUnit test framework
EventBus library integration
BusUtils custom implementation
ReflectUtils for runtime configuration
Systematic performance measurement utilities

Best Practices Demonstrated

The test suite exemplifies several testing best practices:

Proper test isolation and state management
Consistent measurement methodology
Comprehensive edge case coverage
Clear test organization and documentation
Efficient resource cleanup

blankj/androidutilcode

lib/utilcode/src/test/java/com/blankj/utilcode/util/BusUtilsVsEventBusTest.java

            
package com.blankj.utilcode.util;

import org.greenrobot.eventbus.EventBus;
import org.greenrobot.eventbus.Subscribe;
import org.junit.Before;
import org.junit.Test;

import java.util.ArrayList;
import java.util.List;

/**
 * <pre>
 *     author: blankj
 *     blog  : http://blankj.com
 *     time  : 2019/07/14
 *     desc  :
 * </pre>
 */
public class BusUtilsVsEventBusTest extends BaseTest {

    @Subscribe
    public void eventBusFun(String param) {
    }

    @BusUtils.Bus(tag = "busUtilsFun")
    public void busUtilsFun(String param) {
    }

    @Before
    public void setUp() throws Exception {
        // 这一步是在 AOP 的时候注入的，这里通过反射来注入 busUtilsFun 事件，效果是一样的
        ReflectUtils getInstance = ReflectUtils.reflect(BusUtils.class).method("getInstance");
        getInstance.method("registerBus", "busUtilsFun", BusUtilsVsEventBusTest.class.getName(), "busUtilsFun", String.class.getName(), "param", false, "POSTING");
    }

    /**
     * 注册 10000 个订阅者，共执行 10 次取平均值
     */
//    @Test
    public void compareRegister10000Times() {
        final List<BusUtilsVsEventBusTest> eventBusTests = new ArrayList<>();
        final List<BusUtilsVsEventBusTest> busUtilsTests = new ArrayList<>();

        compareWithEventBus("Register 10000 times.", 10, 10000, new CompareCallback() {
            @Override
            public void runEventBus() {
                BusUtilsVsEventBusTest test = new BusUtilsVsEventBusTest();
                EventBus.getDefault().register(test);
                eventBusTests.add(test);
            }

            @Override
            public void runBusUtils() {
                BusUtilsVsEventBusTest test = new BusUtilsVsEventBusTest();
                BusUtils.register(test);
                busUtilsTests.add(test);
            }

            @Override
            public void restState() {
                for (BusUtilsVsEventBusTest test : eventBusTests) {
                    EventBus.getDefault().unregister(test);
                }
                eventBusTests.clear();

                for (BusUtilsVsEventBusTest test : busUtilsTests) {
                    BusUtils.unregister(test);
                }
                busUtilsTests.clear();
            }
        });
    }

    /**
     * 向 1 个订阅者发送 * 1000000 次，共执行 10 次取平均值
     */
//    @Test
    public void comparePostTo1Subscriber1000000Times() {
        comparePostTemplate("Post to 1 subscriber 1000000 times.", 1, 1000000);
    }

    /**
     * 向 100 个订阅者发送 * 100000 次，共执行 10 次取平均值
     */
//    @Test
    public void comparePostTo100Subscribers100000Times() {
        comparePostTemplate("Post to 100 subscribers 100000 times.", 100, 100000);
    }

    private void comparePostTemplate(String name, int subscribeNum, int postTimes) {
        final List<BusUtilsVsEventBusTest> tests = new ArrayList<>();
        for (int i = 0; i < subscribeNum; i++) {
            BusUtilsVsEventBusTest test = new BusUtilsVsEventBusTest();
            EventBus.getDefault().register(test);
            BusUtils.register(test);
            tests.add(test);
        }

        compareWithEventBus(name, 10, postTimes, new CompareCallback() {
            @Override
            public void runEventBus() {
                EventBus.getDefault().post("EventBus");
            }

            @Override
            public void runBusUtils() {
                BusUtils.post("busUtilsFun", "BusUtils");
            }

            @Override
            public void restState() {

            }
        });
        for (BusUtilsVsEventBusTest test : tests) {
            EventBus.getDefault().unregister(test);
            BusUtils.unregister(test);
        }
    }

    /**
     * 注销 10000 个订阅者，共执行 10 次取平均值
     */
//    @Test
    public void compareUnregister10000Times() {
        final List<BusUtilsVsEventBusTest> tests = new ArrayList<>();
        for (int i = 0; i < 10000; i++) {
            BusUtilsVsEventBusTest test = new BusUtilsVsEventBusTest();
            EventBus.getDefault().register(test);
            BusUtils.register(test);
            tests.add(test);
        }

        compareWithEventBus("Unregister 10000 times.", 10, 1, new CompareCallback() {
            @Override
            public void runEventBus() {
                for (BusUtilsVsEventBusTest test : tests) {
                    EventBus.getDefault().unregister(test);
                }
            }

            @Override
            public void runBusUtils() {
                for (BusUtilsVsEventBusTest test : tests) {
                    BusUtils.unregister(test);
                }
            }

            @Override
            public void restState() {
                for (BusUtilsVsEventBusTest test : tests) {
                    EventBus.getDefault().register(test);
                    BusUtils.register(test);
                }
            }
        });

        for (BusUtilsVsEventBusTest test : tests) {
            EventBus.getDefault().unregister(test);
            BusUtils.unregister(test);
        }
    }

    /**
     * @param name       传入的测试函数名
     * @param sampleSize 样本的数量
     * @param times      每次执行的次数
     * @param callback   比较的回调函数
     */
    private void compareWithEventBus(String name, int sampleSize, int times, CompareCallback callback) {
        long[][] dur = new long[2][sampleSize];
        for (int i = 0; i < sampleSize; i++) {
            long cur = System.currentTimeMillis();
            for (int j = 0; j < times; j++) {
                callback.runEventBus();
            }
            dur[0][i] = System.currentTimeMillis() - cur;

            cur = System.currentTimeMillis();
            for (int j = 0; j < times; j++) {
                callback.runBusUtils();
            }
            dur[1][i] = System.currentTimeMillis() - cur;
            callback.restState();
        }
        long eventBusAverageTime = 0;
        long busUtilsAverageTime = 0;
        for (int i = 0; i < sampleSize; i++) {
            eventBusAverageTime += dur[0][i];
            busUtilsAverageTime += dur[1][i];
        }
        System.out.println(
                name +
                "\nEventBusCostTime: " + eventBusAverageTime / sampleSize +
                "\nBusUtilsCostTime: " + busUtilsAverageTime / sampleSize
        );
    }

    public interface CompareCallback {
        void runEventBus();

        void runBusUtils();

        void restState();
    }
}