fix most 2.13 compiler warnings (#1070)

There is still one related to ordering doubles, but is not
easily fixable until the 2.12 build is dropped.

atlas-akka/src/main/scala/com/netflix/atlas/akka/ActorService.scala

@@ -37,7 +37,7 @@ class ActorService @Inject()(system: ActorSystem, config: Config, classFactory:
     with StrictLogging {
 
   override def startImpl(): Unit = {
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
     config.getConfigList("atlas.akka.actors").asScala.foreach { cfg =>
       val name = cfg.getString("name")
       val cls = Class.forName(cfg.getString("class"))

atlas-akka/src/main/scala/com/netflix/atlas/akka/ConfigApi.scala

@@ -84,7 +84,7 @@ class ConfigApi(config: Config, implicit val actorRefFactory: ActorRefFactory) e
   }
 
   private def getPathValue(config: Config, p: String): Config = {
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
     try config.getConfig(p)
     catch {
       case e: ConfigException.WrongType =>
@@ -107,7 +107,7 @@ class ConfigApi(config: Config, implicit val actorRefFactory: ActorRefFactory) e
   }
 
   private def formatProperties(config: Config): HttpResponse = {
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
     val props = new Properties
     config.entrySet.asScala.foreach { t =>
       props.setProperty(t.getKey, s"${t.getValue.unwrapped}")

atlas-akka/src/main/scala/com/netflix/atlas/akka/HealthcheckApi.scala

@@ -49,7 +49,7 @@ class HealthcheckApi(serviceManagerProvider: Provider[ServiceManager])
   private def serviceManager: ServiceManager = serviceManagerProvider.get
 
   private def summary: String = {
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
     val states = serviceManager.services().asScala.map(s => s.name -> s.isHealthy).toMap
     Json.encode(states)
   }

atlas-akka/src/main/scala/com/netflix/atlas/akka/RequestHandler.scala

@@ -55,17 +55,17 @@ class RequestHandler(config: Config, classFactory: ClassFactory) extends StrictL
   }
 
   private def endpoints: List[String] = {
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
     config.getStringList("atlas.akka.api-endpoints").asScala.toList.distinct
   }
 
   private def corsHostPatterns: List[String] = {
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
     config.getStringList("atlas.akka.cors-host-patterns").asScala.toList.distinct
   }
 
   private def diagnosticHeaders: List[HttpHeader] = {
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
     config
       .getConfigList("atlas.akka.diagnostic-headers")
       .asScala

atlas-akka/src/main/scala/com/netflix/atlas/akka/StaticPages.scala

@@ -43,7 +43,7 @@ class StaticPages(config: Config) extends WebApi {
       getFromResourceDirectory("www")
     }
 
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
     val singlePagePrefixes = config.getConfigList("atlas.akka.static.single-page-prefixes")
     singlePagePrefixes.asScala.foldLeft(staticFiles) { (acc, cfg) =>
       val prefix = cfg.getString("prefix")

atlas-akka/src/test/scala/com/netflix/atlas/akka/ConfigApiSuite.scala

@@ -56,7 +56,7 @@ class ConfigApiSuite extends FunSuite with ScalatestRouteTest {
   }
 
   test("/config/os.arch") {
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
     Get("/api/v2/config/os.arch") ~> endpoint.routes ~> check {
       val config = ConfigFactory.parseString(responseAs[String])
       val v = sysConfig.getString("os.arch")
@@ -81,7 +81,7 @@ class ConfigApiSuite extends FunSuite with ScalatestRouteTest {
 
   test("/config format properties") {
     Get("/api/v2/config?format=properties") ~> endpoint.routes ~> check {
-      import scala.collection.JavaConverters._
+      import scala.jdk.CollectionConverters._
       val props = new Properties
       props.load(new StringReader(responseAs[String]))
       val config = ConfigFactory.parseProperties(props)

atlas-akka/src/test/scala/com/netflix/atlas/akka/StreamOpsSuite.scala

@@ -46,7 +46,7 @@ class StreamOpsSuite extends FunSuite {
   private implicit val materializer = ActorMaterializer()
 
   private def checkOfferedCounts(registry: Registry, expected: Map[String, Double]): Unit = {
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
     registry
       .stream()
       .iterator()
@@ -146,7 +146,7 @@ class StreamOpsSuite extends FunSuite {
   }
 
   private def checkCounts(registry: Registry, name: String, expected: Map[String, Double]): Unit = {
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
     registry
       .stream()
       .iterator()

atlas-chart/src/main/scala/com/netflix/atlas/chart/DefaultGraphEngine.scala

@@ -33,7 +33,7 @@ import com.netflix.atlas.core.util.UnitPrefix
 class DefaultGraphEngine extends PngGraphEngine {
 
   private val renderingHints = {
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
     val config = ConfigManager.current.getConfig("atlas.chart.rendering-hints")
     config.entrySet.asScala.toList.map { entry =>
       val k = getField(entry.getKey).asInstanceOf[RenderingHints.Key]

atlas-chart/src/main/scala/com/netflix/atlas/chart/JsonCodec.scala

@@ -298,7 +298,7 @@ private[chart] object JsonCodec {
   private def toGraphDef(node: JsonNode): GraphDef = {
 
     // format: off
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
     GraphDef(
       Nil,
       startTime  = Instant.ofEpochMilli(node.get("startTime").asLong()),
@@ -395,7 +395,7 @@ private[chart] object JsonCodec {
   }
 
   private def toTimeSeries(gdef: GraphDef, node: JsonNode): TimeSeries = {
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
     val tags = node.get("tags").fields.asScala.map(e => e.getKey -> e.getValue.asText()).toMap
     val values = node.get("data").get("values").elements.asScala.map(_.asDouble()).toArray
     val seq = new ArrayTimeSeq(DsType.Gauge, gdef.startTime.toEpochMilli, gdef.step, values)

atlas-core/src/main/scala-2.13+/com/netflix/atlas/core/util/SmallHashMap.scala

@@ -178,7 +178,7 @@ final class SmallHashMap[K <: Any, V <: Any] private (val data: Array[Any], data
 
   def get(key: K): Option[V] = Option(getOrNull(key))
 
-  override def foreach[U](f: ((K, V)) => U) {
+  override def foreach[U](f: ((K, V)) => U): Unit = {
     var i = 0
     while (i < data.length) {
       if (data(i) != null) f(data(i).asInstanceOf[K] -> data(i + 1).asInstanceOf[V])
@@ -426,7 +426,7 @@ final class SmallHashMap[K <: Any, V <: Any] private (val data: Array[Any], data
         * the entry set is needed.
         */
       override def entrySet(): java.util.Set[java.util.Map.Entry[K, V]] = {
-        import scala.collection.JavaConverters._
+        import scala.jdk.CollectionConverters._
         self.asJava.entrySet()
       }
     }

atlas-core/src/main/scala-2.13-/com/netflix/atlas/core/util/SmallHashMap.scala

@@ -426,7 +426,7 @@ final class SmallHashMap[K <: Any, V <: Any] private (val data: Array[Any], data
         * the entry set is needed.
         */
       override def entrySet(): java.util.Set[java.util.Map.Entry[K, V]] = {
-        import scala.collection.JavaConverters._
+        import scala.jdk.CollectionConverters._
         self.asJava.entrySet()
       }
     }

atlas-core/src/main/scala/com/netflix/atlas/core/db/MemoryDatabase.scala

@@ -171,7 +171,7 @@ class MemoryDatabase(registry: Registry, config: Config) extends Database {
         case _: DataExpr.All => tags
         case _ =>
           val resultKeys = Query.exactKeys(expr.query) ++ expr.finalGrouping
-          tags.filterKeys(resultKeys.contains).toMap
+          tags.filter(t => resultKeys.contains(t._1))
       }
       TimeSeriesBuffer(resultTags, cfStep, bufStart, bufEnd)
     }

atlas-core/src/main/scala/com/netflix/atlas/core/index/BatchUpdateTagIndex.scala

@@ -78,7 +78,7 @@ class BatchUpdateTagIndex[T <: TaggedItem: ClassTag](
   def rebuildIndex(): Unit = {
     val timerId = rebuildTimer.start()
     try {
-      import scala.collection.JavaConverters._
+      import scala.jdk.CollectionConverters._
 
       // Drain the update queue and create map of items for deduping, we put new items in the
       // map first so that an older item, if present, will be preferred

atlas-core/src/main/scala/com/netflix/atlas/core/model/CustomVocabulary.scala

@@ -81,7 +81,7 @@ import com.typesafe.config.Config
   */
 class CustomVocabulary(config: Config) extends Vocabulary {
   import CustomVocabulary._
-  import scala.collection.JavaConverters._
+  import scala.jdk.CollectionConverters._
 
   val name: String = "custom"
 

atlas-core/src/main/scala/com/netflix/atlas/core/model/DataExpr.scala

@@ -95,7 +95,9 @@ object DataExpr {
     // 32 is typically big enough to prevent a resize with a single key
     val builder = new StringBuilder(32 * keys.size)
     builder.append('(')
-    keys.foreach { k =>
+    val it = keys.iterator
+    while (it.hasNext) {
+      val k = it.next()
       val v = tags.get(k)
       if (v.isEmpty) return null
       builder.append(k).append('=').append(v.get).append(' ')

atlas-core/src/main/scala/com/netflix/atlas/core/model/StatefulExpr.scala

@@ -266,7 +266,7 @@ object StatefulExpr {
       // Update the stateful buffers for expressions that do not have an explicit value for
       // this interval. For streaming contexts only data that is reported for that interval
       // will be present, but the state needs to be moved for all entries.
-      val noDataIds = state.keySet -- rs.data.map(_.id)
+      val noDataIds = state.keySet.diff(rs.data.map(_.id).toSet)
       noDataIds.foreach { id =>
         val algo = OnlineAlgorithm(state(id))
         algo.next(Double.NaN)

atlas-core/src/main/scala/com/netflix/atlas/core/validation/ReservedKeyRule.scala

@@ -41,7 +41,7 @@ case class ReservedKeyRule(prefix: String, allowedKeys: Set[String]) extends Tag
 object ReservedKeyRule {
 
   def apply(config: Config): ReservedKeyRule = {
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
 
     val prefix = config.getString("prefix")
     val allowedKeys =

atlas-core/src/main/scala/com/netflix/atlas/core/validation/Rule.scala

@@ -54,7 +54,7 @@ trait Rule {
 object Rule {
 
   def load(ruleConfigs: java.util.List[_ <: Config]): List[Rule] = {
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
     load(ruleConfigs.asScala.toList)
   }
 

atlas-core/src/main/scala/com/netflix/atlas/core/validation/ValidCharactersRule.scala

@@ -57,7 +57,7 @@ case class ValidCharactersRule(defaultSet: AsciiSet, overrides: Map[String, Asci
 object ValidCharactersRule {
 
   def apply(config: Config): ValidCharactersRule = {
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
 
     def loadOverrides: Map[String, AsciiSet] = {
       val entries = config.getConfigList("overrides").asScala.map { cfg =>

atlas-core/src/test/scala/com/netflix/atlas/core/index/DataSet.scala

@@ -276,7 +276,7 @@ object DataSet {
           val sps = app + ("name" -> ("sps_" + j))
 
           val idealF = wave(conf._2, conf._3, Duration.ofDays(1))
-          idealF.withTags(sps + ("type" -> "ideal", "type2" -> "IDEAL"))
+          idealF.withTags(sps ++ Seq("type" -> "ideal", "type2" -> "IDEAL"))
         }
       }
     }

atlas-core/src/test/scala/com/netflix/atlas/core/model/BlockSuite.scala

@@ -31,7 +31,7 @@ class BlockSuite extends FunSuite {
     Block.compress(block)
   }
 
-  def checkValues(b: Block, values: List[Double]) {
+  def checkValues(b: Block, values: List[Double]): Unit = {
     values.zipWithIndex.foreach { v =>
       val msg = "b(%d) => %f != %f".format(v._2, b.get(v._2), v._1)
       val res = java.lang.Double.compare(v._1, b.get(v._2))

atlas-core/src/test/scala/com/netflix/atlas/core/model/PercentilesSuite.scala

@@ -85,7 +85,7 @@ class PercentilesSuite extends FunSuite {
   }
 
   private val inputSpectatorTimer = {
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
     val r = new DefaultRegistry()
     val t = PercentileTimer.get(r, r.createId("test"))
     (0 until 100).foreach { i =>
@@ -102,7 +102,7 @@ class PercentilesSuite extends FunSuite {
   }
 
   private val inputSpectatorDistSummary = {
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
     val r = new DefaultRegistry()
     val t = PercentileDistributionSummary.get(r, r.createId("test"))
     (0 until 100).foreach { i =>

atlas-core/src/test/scala/com/netflix/atlas/core/util/SmallHashMapSuite.scala

@@ -284,7 +284,7 @@ class SmallHashMapSuite extends FunSuite {
     assert(expected === actual)
   }
 
-  private def testNumCollisions(m: SmallHashMap[String, String]) {
+  private def testNumCollisions(m: SmallHashMap[String, String]): Unit = {
 
     //printf("%d: %d collisions, %.2f probes%n", m.size, m.numCollisions, m.numProbesPerKey)
     assert(m.numProbesPerKey < m.size / 4)

atlas-eval/src/main/scala/com/netflix/atlas/eval/graph/DefaultSettings.scala

@@ -77,7 +77,7 @@ case class DefaultSettings(root: Config, config: Config) {
 
   /** Available engines for rendering a chart. */
   val engines: Map[String, GraphEngine] = {
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
     config
       .getStringList("engines")
       .asScala
@@ -92,7 +92,7 @@ case class DefaultSettings(root: Config, config: Config) {
   /** Content types for the various rendering options. */
   val contentTypes: Map[String, ContentType] = engines.map {
     case (k, e) =>
-      k -> ContentType.parse(e.contentType).right.get
+      k -> ContentType.parse(e.contentType).toOption.get
   }
 
   /** Vocabulary to use in the interpreter when evaluating a graph expression. */

atlas-eval/src/main/scala/com/netflix/atlas/eval/stream/EurekaGroupsLookup.scala

@@ -55,7 +55,7 @@ private[stream] class EurekaGroupsLookup(context: StreamContext, frequency: Fini
       private var continue = new AtomicBoolean(true)
 
       override def onPush(): Unit = {
-        import scala.collection.JavaConverters._
+        import scala.jdk.CollectionConverters._
 
         // If there is an existing source polling Eureka, then tell it to stop. Create a
         // new instance of the flag for the next source

atlas-eval/src/main/scala/com/netflix/atlas/eval/stream/EvaluatorImpl.scala

@@ -52,7 +52,7 @@ import com.typesafe.config.Config
 import org.reactivestreams.Processor
 import org.reactivestreams.Publisher
 
-import scala.collection.JavaConverters._
+import scala.jdk.CollectionConverters._
 import scala.concurrent.Await
 import scala.concurrent.duration._
 
@@ -265,7 +265,7 @@ private[stream] abstract class EvaluatorImpl(
           exprs.filter(_.query.matches(tags)).map { expr =>
             // Restrict the tags to the common set for all matches to the data expression
             val keys = Query.exactKeys(expr.query) ++ expr.finalGrouping
-            val exprTags = tags.filterKeys(keys.contains).toMap
+            val exprTags = tags.filter(t => keys.contains(t._1))
 
             // Need to do the init for count aggregate
             val v = d.getValue

atlas-eval/src/main/scala/com/netflix/atlas/eval/stream/ExprInterpreter.scala

@@ -57,7 +57,7 @@ private[stream] class ExprInterpreter(config: Config) {
   }
 
   def dataExprMap(ds: DataSources): Map[DataExpr, List[DataSource]] = {
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
     ds.getSources.asScala.toList
       .flatMap { s =>
         val exprs = eval(Uri(s.getUri)).flatMap(_.expr.dataExprs).distinct

atlas-eval/src/main/scala/com/netflix/atlas/eval/stream/FinalExprEval.scala

@@ -84,7 +84,7 @@ private[stream] class FinalExprEval(interpreter: ExprInterpreter)
 
       // Updates the recipients list
       private def handleDataSources(ds: DataSources): Unit = {
-        import scala.collection.JavaConverters._
+        import scala.jdk.CollectionConverters._
         val sources = ds.getSources.asScala.toList
         step = ds.stepSize()
 

atlas-eval/src/main/scala/com/netflix/atlas/eval/stream/StreamContext.scala

@@ -61,7 +61,7 @@ private[stream] class StreamContext(
   private val config = rootConfig.getConfig("atlas.eval.stream")
 
   private val backends = {
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
     config.getConfigList("backends").asScala.toList.map { cfg =>
       EurekaBackend(
         cfg.getString("host"),
@@ -72,7 +72,7 @@ private[stream] class StreamContext(
   }
 
   private val ignoredTagKeys = {
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
     config.getStringList("ignored-tag-keys").asScala.toSet
   }
 
@@ -123,7 +123,7 @@ private[stream] class StreamContext(
     * message will be written to the `dsLogger` for any failures.
     */
   def validate(input: DataSources): DataSources = {
-    import scala.collection.JavaConverters._
+    import scala.jdk.CollectionConverters._
     val valid = new java.util.HashSet[DataSource]()
     input.getSources.asScala.foreach { ds =>
       validateDataSource(ds) match {

atlas-eval/src/main/scala/com/netflix/atlas/eval/stream/SubscriptionManager.scala

@@ -90,7 +90,7 @@ private[stream] class SubscriptionManager(context: StreamContext)
 
       private def handleDataSources(dataSources: DataSources): Unit = {
         // Log changes to the data sources for easier debugging
-        import scala.collection.JavaConverters._
+        import scala.jdk.CollectionConverters._
         logSources("added", dataSources.addedSources(sources).asScala.toList)
         logSources("removed", dataSources.removedSources(sources).asScala.toList)
         sources = dataSources

atlas-eval/src/main/scala/com/netflix/atlas/eval/stream/TimeGrouped.scala

@@ -107,7 +107,7 @@ private[stream] class TimeGrouped(
         * so it can be used for a new time window.
         */
       private def flush(i: Int): Unit = {
-        val vs = buf(i).mapValues(_.datapoints).toMap
+        val vs = buf(i).map(t => t._1 -> t._2.datapoints).toMap
         val t = timestamps(i)
         if (t > 0) push(out, TimeGroup(t, step, vs)) else pull(in)
         cutoffTime = t
@@ -149,7 +149,7 @@ private[stream] class TimeGrouped(
 
       override def onUpstreamFinish(): Unit = {
         val groups = buf.indices.map { i =>
-          val vs = buf(i).mapValues(_.datapoints).toMap
+          val vs = buf(i).map(t => t._1 -> t._2.datapoints).toMap
           TimeGroup(timestamps(i), step, vs)
         }.toList
         pending = groups.filter(_.timestamp > 0).sortWith(_.timestamp < _.timestamp)