Extract runtime image creation into separate task

This change speeds up incremental build of
an application image.
For example, for one (relatively small) tested application
the overall time spent on creating binary images in incremental case
(after one file change) went from ~5 seconds down to 1.4 seconds
(non-rigorous benchmark using a relatively fast 8-core 2.3Ghz i9 MBP).

gradle-plugins/compose/src/main/kotlin/org/jetbrains/compose/desktop/application/dsl/RuntimeCompressionLevel.kt

@@ -0,0 +1,9 @@
+package org.jetbrains.compose.desktop.application.dsl
+
+internal enum class RuntimeCompressionLevel(internal val id: Int) {
+    // For ID values see the docs on "--compress" https://docs.oracle.com/javase/9/tools/jlink.htm
+
+    NO_COMPRESSION(0),
+    CONSTANT_STRING_SHARING(1),
+    ZIP(2)
+}

gradle-plugins/compose/src/main/kotlin/org/jetbrains/compose/desktop/application/internal/configureApplication.kt

@@ -9,6 +9,7 @@ import org.gradle.api.tasks.*
 import org.gradle.jvm.tasks.Jar
 import org.jetbrains.compose.desktop.application.dsl.Application
 import org.jetbrains.compose.desktop.application.dsl.TargetFormat
+import org.jetbrains.compose.desktop.application.tasks.AbstractJLinkTask
 import org.jetbrains.compose.desktop.application.tasks.AbstractJPackageTask
 import org.jetbrains.compose.desktop.application.tasks.AbstractRunDistributableTask
 import org.jetbrains.kotlin.gradle.dsl.KotlinMultiplatformExtension
@@ -56,12 +57,20 @@ internal fun Project.configurePackagingTasks(apps: Collection<Application>) {
             configureRunTask(app)
         }
 
+        val createRuntimeImage = tasks.composeTask<AbstractJLinkTask>(
+            taskName("createRuntimeImage", app)
+        ) {
+            javaHome.set(provider { app.javaHomeOrDefault() })
+            modules.set(provider { app.nativeDistributions.modules })
+            destinationDir.set(project.layout.buildDirectory.dir("compose/tmp/${app.name}/runtime"))
+        }
+
         val packageFormats = app.nativeDistributions.targetFormats.map { targetFormat ->
             tasks.composeTask<AbstractJPackageTask>(
                 taskName("package", app, targetFormat.name),
                 args = listOf(targetFormat)
             ) {
-                configurePackagingTask(app)
+                configurePackagingTask(app, createRuntimeImage)
             }
         }
 
@@ -77,7 +86,7 @@ internal fun Project.configurePackagingTasks(apps: Collection<Application>) {
             taskName("createDistributable", app),
             args = listOf(TargetFormat.AppImage)
         ) {
-            configurePackagingTask(app)
+            configurePackagingTask(app, createRuntimeImage)
         }
 
         val runDistributable = project.tasks.composeTask<AbstractRunDistributableTask>(
@@ -88,10 +97,15 @@ internal fun Project.configurePackagingTasks(apps: Collection<Application>) {
 }
 
 internal fun AbstractJPackageTask.configurePackagingTask(
-    app: Application
+    app: Application,
+    createRuntimeImage: TaskProvider<AbstractJLinkTask>
 ) {
     enabled = targetFormat.isCompatibleWithCurrentOS
 
+    val runtimeImageDir = createRuntimeImage.flatMap { it.destinationDir }
+    dependsOn(createRuntimeImage)
+    runtimeImage.set(runtimeImageDir)
+
     configurePlatformSettings(app)
 
     app.nativeDistributions.let { executables ->
@@ -115,7 +129,6 @@ internal fun AbstractJPackageTask.configurePackagingTask(
         launcherMainJar.set(app.mainJar.orElse(configSource.jarTask(project).flatMap { it.archiveFile }))
     }
 
-    modules.set(provider { app.nativeDistributions.modules })
     launcherMainClass.set(provider { app.mainClass })
     launcherJvmArgs.set(provider { app.jvmArgs })
     launcherArgs.set(provider { app.args })
@@ -205,7 +218,7 @@ private fun Jar.configurePackageUberJarForCurrentOS(app: Application) {
         destinationDirectory.set(project.layout.buildDirectory.dir("compose/jars"))
 
         doLast {
-            logger.lifecycle("The jar is written to ${archiveFile.get().asFile.canonicalPath}")
+            logger.lifecycle("The jar is written to ${archiveFile.ioFile.canonicalPath}")
         }
     }
 

gradle-plugins/compose/src/main/kotlin/org/jetbrains/compose/desktop/application/internal/dslUtils.kt

@@ -12,5 +12,8 @@ internal inline fun <reified T : Any> ObjectFactory.nullableProperty(): Property
 internal inline fun <reified T : Any> ObjectFactory.notNullProperty(): Property<T> =
     property(T::class.java)
 
+internal inline fun <reified T : Any> ObjectFactory.notNullProperty(defaultValue: T): Property<T> =
+    property(T::class.java).value(defaultValue)
+
 internal inline fun <reified T> Task.provider(noinline fn: () -> T): Provider<T> =
     project.provider(fn)

gradle-plugins/compose/src/main/kotlin/org/jetbrains/compose/desktop/application/internal/gradleUtils.kt

@@ -0,0 +1,11 @@
+package org.jetbrains.compose.desktop.application.internal
+
+import org.gradle.api.file.FileSystemLocation
+import org.gradle.api.provider.Provider
+import java.io.File
+
+internal val <T : FileSystemLocation> Provider<T>.ioFile: File
+    get() = get().asFile
+
+internal val <T : FileSystemLocation> Provider<T>.ioFileOrNull: File?
+    get() = orNull?.asFile

gradle-plugins/compose/src/main/kotlin/org/jetbrains/compose/desktop/application/tasks/AbstractJLinkTask.kt

@@ -0,0 +1,48 @@
+package org.jetbrains.compose.desktop.application.tasks
+
+import org.gradle.api.provider.ListProperty
+import org.gradle.api.provider.Property
+import org.gradle.api.tasks.Input
+import org.gradle.api.tasks.Optional
+import org.jetbrains.compose.desktop.application.dsl.RuntimeCompressionLevel
+import org.jetbrains.compose.desktop.application.internal.cliArg
+import org.jetbrains.compose.desktop.application.internal.notNullProperty
+import org.jetbrains.compose.desktop.application.internal.nullableProperty
+import java.io.File
+
+// todo: public DSL
+// todo: deduplicate if multiple runtimes are created
+abstract class AbstractJLinkTask : AbstractJvmToolOperationTask("jlink") {
+    @get:Input
+    val modules: ListProperty<String> = objects.listProperty(String::class.java)
+
+    @get:Input
+    internal val stripDebug: Property<Boolean> = objects.notNullProperty(true)
+
+    @get:Input
+    internal val noHeaderFiles: Property<Boolean> = objects.notNullProperty(true)
+
+    @get:Input
+    internal val noManPages: Property<Boolean> = objects.notNullProperty(true)
+
+    @get:Input
+    internal val stripNativeCommands: Property<Boolean> = objects.notNullProperty(true)
+
+    @get:Input
+    @get:Optional
+    internal val compressionLevel: Property<RuntimeCompressionLevel?> = objects.nullableProperty()
+
+    override fun makeArgs(tmpDir: File): MutableList<String> = super.makeArgs(tmpDir).apply {
+        modules.get().forEach { m ->
+            cliArg("--add-modules", m)
+        }
+
+        cliArg("--strip-debug", stripDebug)
+        cliArg("--no-header-files", noHeaderFiles)
+        cliArg("--no-man-pages", noManPages)
+        cliArg("--strip-native-commands", stripNativeCommands)
+        cliArg("--compress", compressionLevel.orNull?.id )
+
+        cliArg("--output", destinationDir)
+    }
+}

gradle-plugins/compose/src/main/kotlin/org/jetbrains/compose/desktop/application/tasks/AbstractJPackageTask.kt

@@ -19,9 +19,6 @@ abstract class AbstractJPackageTask @Inject constructor(
     @get:Input
     val targetFormat: TargetFormat,
 ) : AbstractJvmToolOperationTask("jpackage") {
-    @get:OutputDirectory
-    val destinationDir: DirectoryProperty = objects.directoryProperty()
-
     @get:InputFiles
     val files: ConfigurableFileCollection = objects.fileCollection()
 
@@ -158,19 +155,20 @@ abstract class AbstractJPackageTask @Inject constructor(
     @get:Optional
     val winUpgradeUuid: Property<String?> = objects.nullableProperty()
 
-    @get:Input
-    val modules: ListProperty<String> = objects.listProperty(String::class.java)
+    @get:InputDirectory
+    @get:Optional
+    val runtimeImage: DirectoryProperty = objects.directoryProperty()
 
     override fun makeArgs(tmpDir: File): MutableList<String> = super.makeArgs(tmpDir).apply {
         cliArg("--input", tmpDir)
         cliArg("--type", targetFormat.id)
 
-        cliArg("--dest", destinationDir.asFile.get())
+        cliArg("--dest", destinationDir.ioFile)
         cliArg("--verbose", verbose)
 
         cliArg("--install-dir", installationPath)
-        cliArg("--license-file", licenseFile.asFile.orNull)
-        cliArg("--icon", iconFile.asFile.orNull)
+        cliArg("--license-file", licenseFile.ioFileOrNull)
+        cliArg("--icon", iconFile.ioFileOrNull)
 
         cliArg("--name", packageName)
         cliArg("--description", packageDescription)
@@ -178,7 +176,7 @@ abstract class AbstractJPackageTask @Inject constructor(
         cliArg("--app-version", packageVersion)
         cliArg("--vendor", packageVendor)
 
-        cliArg("--main-jar", launcherMainJar.asFile.get().name)
+        cliArg("--main-jar", launcherMainJar.ioFile.name)
         cliArg("--main-class", launcherMainClass)
         launcherArgs.orNull?.forEach {
             cliArg("--arguments", it)
@@ -202,7 +200,7 @@ abstract class AbstractJPackageTask @Inject constructor(
                 cliArg("--mac-package-name", macPackageName)
                 cliArg("--mac-bundle-signing-prefix", macBundleSigningPrefix)
                 cliArg("--mac-sign", macSign)
-                cliArg("--mac-signing-keychain", macSigningKeychain.asFile.orNull)
+                cliArg("--mac-signing-keychain", macSigningKeychain.ioFileOrNull)
                 cliArg("--mac-signing-key-user-name", macSigningKeyUserName)
             }
             OS.Windows -> {
@@ -216,13 +214,11 @@ abstract class AbstractJPackageTask @Inject constructor(
             }
         }
 
-        modules.get().forEach { m ->
-            cliArg("--add-modules", m)
-        }
+        cliArg("--runtime-image", runtimeImage)
     }
 
     override fun prepareWorkingDir(inputChanges: InputChanges) {
-        fileOperations.delete(destinationDir)
+        val workingDir = workingDir.ioFile
 
         if (inputChanges.isIncremental) {
             logger.debug("Updating working dir incrementally: $workingDir")
@@ -243,7 +239,7 @@ abstract class AbstractJPackageTask @Inject constructor(
         } else {
             logger.debug("Updating working dir non-incrementally: $workingDir")
             fileOperations.delete(workingDir)
-            workingDir.mkdirs()
+            fileOperations.mkdir(workingDir)
             fileOperations.copy {
                 it.from(files)
                 it.from(launcherMainJar)
@@ -259,7 +255,7 @@ abstract class AbstractJPackageTask @Inject constructor(
 
     private fun configureWixPathIfNeeded(exec: ExecSpec) {
         if (currentOS == OS.Windows) {
-            val wixDir = wixToolsetDir.asFile.orNull ?: return
+            val wixDir = wixToolsetDir.ioFileOrNull ?: return
             val wixPath = wixDir.absolutePath
             val path = System.getenv("PATH") ?: ""
             exec.environment("PATH", "$wixPath;$path")
@@ -269,10 +265,11 @@ abstract class AbstractJPackageTask @Inject constructor(
     override fun checkResult(result: ExecResult) {
         super.checkResult(result)
 
-        val destinationDirFile = destinationDir.asFile.get()
-        val finalLocation = when (targetFormat) {
-            TargetFormat.AppImage -> destinationDirFile
-            else -> destinationDirFile.walk().first { it.isFile && it.name.endsWith(targetFormat.fileExt) }
+        val finalLocation = destinationDir.ioFile.let { destinationDir ->
+            when (targetFormat) {
+                TargetFormat.AppImage -> destinationDir
+                else -> destinationDir.walk().first { it.isFile && it.name.endsWith(targetFormat.fileExt) }
+            }
         }
         logger.lifecycle("The distribution is written to ${finalLocation.canonicalPath}")
     }

gradle-plugins/compose/src/main/kotlin/org/jetbrains/compose/desktop/application/tasks/AbstractJvmToolOperationTask.kt

@@ -1,16 +1,20 @@
 package org.jetbrains.compose.desktop.application.tasks
 
 import org.gradle.api.DefaultTask
+import org.gradle.api.file.Directory
+import org.gradle.api.file.DirectoryProperty
 import org.gradle.api.internal.file.FileOperations
 import org.gradle.api.model.ObjectFactory
 import org.gradle.api.provider.ListProperty
 import org.gradle.api.provider.Property
+import org.gradle.api.provider.Provider
 import org.gradle.api.provider.ProviderFactory
 import org.gradle.api.tasks.*
 import org.gradle.process.ExecOperations
 import org.gradle.process.ExecResult
 import org.gradle.process.ExecSpec
 import org.gradle.work.InputChanges
+import org.jetbrains.compose.desktop.application.internal.*
 import org.jetbrains.compose.desktop.application.internal.ComposeProperties
 import org.jetbrains.compose.desktop.application.internal.OS
 import org.jetbrains.compose.desktop.application.internal.currentOS
@@ -29,7 +33,10 @@ abstract class AbstractJvmToolOperationTask(private val toolName: String) : Defa
     protected abstract val fileOperations: FileOperations
 
     @get:LocalState
-    protected val workingDir: File = project.buildDir.resolve("compose/tmp/$name")
+    protected val workingDir: Provider<Directory> = project.layout.buildDirectory.dir("compose/tmp/$name")
+
+    @get:OutputDirectory
+    val destinationDir: DirectoryProperty = objects.directoryProperty()
 
     @get:Input
     @get:Optional
@@ -47,7 +54,7 @@ abstract class AbstractJvmToolOperationTask(private val toolName: String) : Defa
 
     protected open fun prepareWorkingDir(inputChanges: InputChanges) {
         fileOperations.delete(workingDir)
-        workingDir.mkdirs()
+        fileOperations.mkdir(workingDir)
     }
 
     protected open fun makeArgs(tmpDir: File): MutableList<String> = arrayListOf<String>().apply {
@@ -69,10 +76,14 @@ abstract class AbstractJvmToolOperationTask(private val toolName: String) : Defa
                     "Ensure JAVA_HOME or buildSettings.javaHome is set to JDK 14 or newer"
         }
 
+        fileOperations.delete(destinationDir)
         prepareWorkingDir(inputChanges)
-        val args = makeArgs(workingDir)
-        val argsFile = workingDir.parentFile.resolve("${name}.args.txt")
-        argsFile.writeText(args.joinToString("\n"))
+        val argsFile = workingDir.ioFile.let { dir ->
+            val args = makeArgs(dir)
+            dir.resolveSibling("${name}.args.txt").apply {
+                writeText(args.joinToString("\n"))
+            }
+        }
 
         try {
             execOperations.exec { exec ->

gradle-plugins/compose/src/main/kotlin/org/jetbrains/compose/desktop/application/tasks/AbstractRunDistributableTask.kt

@@ -29,9 +29,8 @@ abstract class AbstractRunDistributableTask @Inject constructor(
 
     @TaskAction
     fun run() {
-        val appDir = appImageRootDir.get().let { appImageRoot ->
-            val files = appImageRoot.asFile.listFiles()
-
+        val appDir = appImageRootDir.ioFile.let { appImageRoot ->
+            val files = appImageRoot.listFiles()
             if (files == null || files.isEmpty()) {
                 error("Could not find application image: $appImageRoot is empty!")
             } else if (files.size > 1) {