Simplify runtimeProperties: make it lazy static field

Author: nikitinas

src/main/kotlin/org/jetbrains/kotlin/jupyter/config.kt

@@ -40,14 +40,13 @@ enum class JupyterSockets {
     iopub
 }
 
-data class RuntimeKernelProperties(
-        var version: String = "unspecified"
-) {
-    constructor(map: Map<String, String>?) : this() {
-        if (map == null)
-            return
-        version = map["version"] ?: version
-    }
+data class RuntimeKernelProperties(val map: Map<String, String>) {
+    val version: String
+        get() = map["version"] ?: "unspecified"
+}
+
+val runtimeProperties by lazy {
+    RuntimeKernelProperties(ClassLoader.getSystemResource("runtime.properties")?.readText()?.parseIniConfig().orEmpty())
 }
 
 data class KernelConfig(
@@ -57,8 +56,7 @@ data class KernelConfig(
         val signatureKey: String,
         val pollingIntervalMillis: Long = 100,
         val scriptClasspath: List<File> = emptyList(),
-        val resolverConfig: ResolverConfig?,
-        val runtimeProperties: RuntimeKernelProperties = RuntimeKernelProperties()
+        val resolverConfig: ResolverConfig?
 )
 
 val protocolVersion = "5.3"

src/main/kotlin/org/jetbrains/kotlin/jupyter/ikotlin.kt

@@ -45,14 +45,6 @@ fun printClassPath() {
         log.info("Current classpath: " + cp.joinToString())
 }
 
-fun loadRuntimeProperties(): RuntimeKernelProperties {
-    val map = object{}.javaClass.classLoader
-            .getResource("runtime.properties")
-            ?.readText()?.parseIniConfig()
-
-    return RuntimeKernelProperties(map)
-}
-
 fun main(vararg args: String) {
     try {
         log.info("Kernel args: "+ args.joinToString { it })
@@ -70,8 +62,7 @@ fun main(vararg args: String) {
                 signatureScheme = sigScheme ?: "hmac1-sha256",
                 signatureKey = if (sigScheme == null || key == null) "" else key,
                 scriptClasspath = scriptClasspath,
-                resolverConfig = loadResolverConfig(rootPath),
-                runtimeProperties = loadRuntimeProperties()
+                resolverConfig = loadResolverConfig(rootPath)
         ))
     } catch (e: Exception) {
         log.error("exception running kernel with args: \"${args.joinToString()}\"", e)
@@ -89,7 +80,7 @@ fun kernelServer(config: KernelConfig) {
 
         val executionCount = AtomicLong(1)
 
-        val repl = ReplForJupyter(config.scriptClasspath, config.resolverConfig, config.runtimeProperties)
+        val repl = ReplForJupyter(config.scriptClasspath, config.resolverConfig)
 
         val mainThread = Thread.currentThread()
 

src/main/kotlin/org/jetbrains/kotlin/jupyter/protocol.kt

@@ -22,7 +22,6 @@ data class ResponseWithMessage(val state: ResponseState, val result: MimeTypedRe
 
 fun JupyterConnection.Socket.shellMessagesHandler(msg: Message, repl: ReplForJupyter?, executionCount: AtomicLong) {
     val msgType = msg.header!!["msg_type"]
-    val replProperties = repl?.properties ?: RuntimeKernelProperties()
     when (msgType) {
         "kernel_info_request" ->
             sendWrapped(msg, makeReplyMessage(msg, "kernel_info_reply",
@@ -42,7 +41,7 @@ fun JupyterConnection.Socket.shellMessagesHandler(msg: Message, repl: ReplForJup
                             // Jupyter lab Console support
                             "banner" to "Kotlin language, version ${KotlinCompilerVersion.VERSION}",
                             "implementation" to "Kotlin",
-                            "implementation_version" to replProperties.version,
+                            "implementation_version" to runtimeProperties.version,
                             "status" to "ok"
                     )))
         "history_request" ->

src/main/kotlin/org/jetbrains/kotlin/jupyter/repl.kt

@@ -38,8 +38,7 @@ class ReplCompilerException(val errorResult: ReplCompileResult.Error) : ReplExce
 }
 
 class ReplForJupyter(val scriptClasspath: List<File> = emptyList(),
-                     val config: ResolverConfig? = null,
-                     val properties: RuntimeKernelProperties = RuntimeKernelProperties()) {
+                     val config: ResolverConfig? = null) {
 
     private val resolver = JupyterScriptDependenciesResolver(config)