build.gradle

plugins {
    id 'me.champeau.jmh' version '0.7.2'
    id 'io.morethan.jmhreport' version "0.9.6"
}

apply plugin: 'io.morethan.jmhreport'

allprojects {
    group = 'io.github.joeljeremy7.java.config.lib.benchmarks'
    version = '1.0.0-SNAPSHOT'

    repositories {
        mavenLocal()
        mavenCentral()
    }
}

def javaProjects = subprojects.findAll { new File(it.projectDir, "src").exists() }

configure(javaProjects) {
    apply plugin: 'java-library'
    apply plugin: 'me.champeau.jmh'

    java {
        toolchain {
            languageVersion = JavaLanguageVersion.of(25)
        }
    }

    jmh {
        jmhVersion = '1.37'
        // humanOutputFile = project.file("${project.buildDir}/reports/jmh/human.txt")
        resultsFile = project.file("${file(layout.buildDirectory)}/reports/jmh/results.json")
        resultFormat = 'JSON'
        jvmArgs = [ '-Xmx2G' ]
        failOnError = true
        // Warmup
        warmup = '5s'
        warmupIterations = 3
        // Benchmarks
        timeOnIteration = '5s'
        iterations = 5
        fork = 2
        // profilers = ["async:libPath=${file(rootProject.layout.projectDirectory)}/lib/async-profiler/lib/libasyncProfiler.so;output=flamegraph;dir=${file(layout.buildDirectory)}/reports/jmh/async-profiler"]
    }
}

import groovy.json.*;

def mergedJmhResultsDir = "${project.rootDir}/merged-jmh-results"

tasks.register('mergeJmhResults') {
    doLast {
        mkdir mergedJmhResultsDir
        def mergedResultsFile = new File("${mergedJmhResultsDir}/merged-jmh-results.json");

        def slurper = new JsonSlurper()
        def mergedResults = slurper.parseText('[]')

        javaProjects.each {
            def projectResultsFile = new File("${it.buildDir}/reports/jmh/results.json");
            if (projectResultsFile.exists() && !projectResultsFile.text.isEmpty()) {
                println "Merging JMH result file ${projectResultsFile}"
                def results = slurper.parseText(projectResultsFile.text)
                mergedResults += results
            } else {
                println "Project ${it.projectPath} has no JMH results. Skipping..."
            }
        }

        mergedResultsFile.text = JsonOutput.prettyPrint(new JsonBuilder(mergedResults).toString())
        println "Merged JMH result file can be found in ${mergedResultsFile}."
    }
}
tasks.jmh.finalizedBy tasks.mergeJmhResults

jmhReport {
    jmhResultPath = project.file("${mergedJmhResultsDir}/merged-jmh-results.json")
    jmhReportOutput = project.file("${mergedJmhResultsDir}")
}
tasks.mergeJmhResults.finalizedBy tasks.jmhReport