chore: Async profiler 4.0 flamegraph and heatmap support

Author: sureshg

backend/jvm/src/main/kotlin/dev/suresh/routes/Mgmt.kt

@@ -149,22 +149,28 @@ fun Route.mgmtRoutes() {
     }
   }
 
-  get("/profile") {
+  get("/profile/{type?}") {
     when (mutex.isLocked) {
       true -> call.respondText("Profile operation is already running")
       else ->
           mutex.withLock {
-            when (call.request.queryParameters.contains("download")) {
-              true -> {
+            val type = call.parameters["type"]?.lowercase() ?: "html"
+            when (type) {
+              "download" -> {
                 val jfrPath = Profiling.jfrSnapshot()
                 call.response.header(
                     ContentDisposition,
                     Attachment.withParameter(FileName, jfrPath.fileName.name).toString())
                 call.respondFile(jfrPath.toFile())
                 jfrPath.deleteIfExists()
               }
-              else ->
-                  call.respondText(contentType = ContentType.Text.Html) { Profiling.flameGraph() }
+
+              "html",
+              "heatmap" ->
+                  call.respondText(contentType = ContentType.Text.Html) {
+                    Profiling.convertJfr(type)
+                  }
+              else -> error("Invalid profile type: $type")
             }
           }
     }

backend/profiling/build.gradle.kts

@@ -17,7 +17,8 @@ kotlin {
       dependencies {
         implementation(libs.jmc.common)
         implementation(libs.jmc.jfr)
-        implementation(libs.ap.converter)
+        implementation(libs.ap.jfr.converter)
+        implementation(libs.bytesize)
         // implementation(libs.ap.loader.all)
       }
       kotlin.srcDir("src/main/kotlin")

backend/profiling/src/main/kotlin/dev/suresh/Profiling.kt

@@ -2,28 +2,25 @@
 
 package dev.suresh
 
-import Arguments
-import FlameGraph
+import BuildConfig
 import com.sun.management.HotSpotDiagnosticMXBean
 import io.github.oshai.kotlinlogging.KotlinLogging
 import java.io.ByteArrayOutputStream
-import java.io.PrintStream
 import java.lang.management.ManagementFactory
 import java.nio.charset.StandardCharsets
 import java.nio.file.Path
 import jdk.jfr.Configuration
 import jdk.jfr.FlightRecorder
 import jdk.jfr.consumer.RecordingStream
 import jdk.management.VirtualThreadSchedulerMXBean
-import jfr2flame
-import kotlin.io.path.createTempFile
-import kotlin.io.path.deleteIfExists
-import kotlin.io.path.pathString
+import kotlin.io.path.*
 import kotlin.time.Duration
 import kotlin.time.Duration.Companion.milliseconds
 import kotlin.time.Duration.Companion.minutes
 import kotlin.time.Duration.Companion.seconds
 import kotlin.time.toJavaDuration
+import me.saket.bytesize.binaryBytes
+import one.convert.*
 import one.jfr.JfrReader
 
 object Profiling {
@@ -85,20 +82,36 @@ object Profiling {
                 }
               }
         }
-        log.info { "JFR file written to ${jfrPath.toAbsolutePath()}" }
+        log.info {
+          "JFR file written to ${jfrPath.toAbsolutePath()} (${jfrPath.fileSize().binaryBytes})"
+        }
         jfrPath
       }
 
-  suspend fun flameGraph(maxAge: Duration = 2.minutes): String = runOnVirtualThread {
-    val jfrPath = jfrSnapshot(maxAge = maxAge, maxSizeBytes = 100_000_000)
-    JfrReader(jfrPath.pathString).use {
-      val jfr2flame = jfr2flame(it, Arguments())
-      val flameGraph = FlameGraph()
-      jfr2flame.convert(flameGraph)
-      val bos = ByteArrayOutputStream()
-      flameGraph.dump(PrintStream(bos))
-      jfrPath.deleteIfExists()
-      bos.toString(StandardCharsets.UTF_8)
-    }
-  }
+  suspend fun convertJfr(format: String = "html", maxAge: Duration = 2.minutes): String =
+      runOnVirtualThread {
+        val jfrPath = jfrSnapshot(maxAge, 100_000_000)
+        val args = Arguments("--output", format, "--reverse", "--title", BuildConfig.name)
+
+        val converter =
+            JfrReader(jfrPath.pathString).use {
+              when (format) {
+                "heatmap" -> JfrToHeatmap(it, args)
+                "html" -> JfrToFlame(it, args)
+                else -> error("Unsupported format: $format")
+              }.apply { convert() }
+            }
+
+        val result =
+            ByteArrayOutputStream().use { out ->
+              when (converter) {
+                is JfrToHeatmap -> converter.dump(out)
+                is JfrToFlame -> converter.dump(out)
+                else -> error("Unsupported converter for $format")
+              }
+              out.toString(StandardCharsets.UTF_8)
+            }
+        jfrPath.deleteIfExists()
+        result
+      }
 }

gradle/libs.versions.toml

@@ -39,7 +39,7 @@ kotlinx-benchmark              = "0.4.13"
 kotlinx-fuzz                   = "0.2.2"
 kotlinx-metadata               = "0.9.0"
 kotlinx-reflect-lite           = "1.1.0"
-kotlin-wrappers                = "2025.4.15"
+kotlin-wrappers                = "2025.4.16"
 kotlin-redacted                = "1.13.0"
 kotlin-serviceloader           = "0.0.15"
 kotlinx-multik                 = "0.2.3"
@@ -58,7 +58,7 @@ decoroutinator                 = "2.4.8"
 spring-boot                    = "3.4.4"
 spring-depmgmt                 = "1.1.7"
 ktor                           = "3.1.2"
-ktor-cohort                    = "2.6.2"
+ktor-cohort                    = "2.7.0"
 otel                           = "1.49.0"
 otel-instr                     = "2.15.0"
 otel-instr-alpha               = "2.15.0-alpha"
@@ -88,11 +88,11 @@ oshi                           = "6.8.1"
 junit                          = "5.13.0-M2"
 koin                           = "4.1.0-Beta7"
 koin-annotations               = "2.0.1-Beta1"
-metro                          = "0.1.2"
+metro                          = "0.2.0"
 kotest                         = "6.0.0.M3"
 mockk                          = "1.14.0"
 mokkery                        = "2.7.2"
-wiremock                       = "3.12.1"
+wiremock                       = "4.0.0-beta.1"
 wiremock-kotlin                = "2.1.1"
 okhttp                         = "5.0.0-alpha.14"
 slf4j                          = "2.1.0-alpha1"
@@ -135,7 +135,7 @@ ksoup                          = "0.2.2"
 java-keyring                   = "1.0.4"
 java-keychain                  = "1.1.0"
 webjars-xterm                  = "5.1.0"
-arrow-suspendapp               = "0.5.0"
+arrow-suspendapp               = "2.1.0"
 exposed                        = "0.61.0"
 postgresql                     = "42.7.5"
 hikariCP                       = "6.3.0"
@@ -158,8 +158,8 @@ tcp-javanioproxy               = "1.6"
 kubernetes-client              = "23.0.0"
 reflect-typeparamresolver      = "1.0.3"
 reflect-typetools              = "0.6.3"
-async-profiler                 = "3.0"
-ap-loader-all                  = "3.0-9"
+async-profiler                 = "4.0"
+ap-loader-all                  = "4.0-10"
 openjdk-jmc                    = "9.1.0"
 airlift-aircompressor          = "2.0.2"
 airlift-security               = "332"
@@ -549,7 +549,7 @@ sourceBuddy                          = { module = "com.javax0.sourcebuddy:Source
 maven-mima                           = { module = "eu.maveniverse.maven.mima:mima"                             , version.ref = "maven-mima"}
 maven-archeologist                   = { module = "com.squareup.tools.build:maven-archeologist"                , version.ref = "maven-archeologist"}
 
-ap-converter                         = { module = "tools.profiler:async-profiler-converter"                    , version.ref = "async-profiler" }
+ap-jfr-converter                     = { module = "tools.profiler:jfr-converter"                               , version.ref = "async-profiler" }
 ap-loader-all                        = { module = "me.bechberger:ap-loader-all"                                , version.ref = "ap-loader-all"}
 jmc-common                           = { module = "org.openjdk.jmc:common"                                     , version.ref = "openjdk-jmc"}
 jmc-jfr                              = { module = "org.openjdk.jmc:flightrecorder"                             , version.ref = "openjdk-jmc"}