fix unused imports and minor warnings (#1578)

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

@@ -32,7 +32,7 @@ class CsvGraphEngine(val name: String, val contentType: String, sep: String) ext
     val numberFmt = config.numberFormat
     writer.append("\"timestamp\"")
     (0 until count).zip(seriesList).map {
-      case (i, series) =>
+      case (_, series) =>
         val label = "\"%s\"".format(series.data.label)
         writer.append(sep).append(label)
     }

atlas-chart/src/main/scala/com/netflix/atlas/chart/graphics/ChartSettings.scala

@@ -20,10 +20,11 @@ import java.awt.Font
 import java.awt.Stroke
 import java.awt.image.BufferedImage
 import java.util.concurrent.ConcurrentHashMap
-
 import com.netflix.atlas.chart.util.Fonts
 import com.netflix.iep.config.ConfigManager
 
+import java.awt.Graphics2D
+
 object ChartSettings {
 
   private val config = ConfigManager.dynamicConfig().getConfig("atlas.chart")
@@ -52,7 +53,7 @@ object ChartSettings {
     * is created.
     */
   val refImage = new BufferedImage(1, 1, BufferedImage.TYPE_INT_ARGB)
-  val refGraphics = refImage.createGraphics()
+  val refGraphics: Graphics2D = refImage.createGraphics()
 
   /** Dashed stroke typically used for grid lines. */
   val dashedStroke: Stroke = {
@@ -69,38 +70,38 @@ object ChartSettings {
   /**
     * Base monospaced font used for graphics. Monospace is used to make the layout easier.
     */
-  val monospaceFont = Fonts.loadFont(config.getString("fonts.monospace"))
+  val monospaceFont: Font = Fonts.loadFont(config.getString("fonts.monospace"))
 
   /** Small sized monospaced font. */
-  val smallFont = monospaceFont.deriveFont(10.0f)
+  val smallFont: Font = monospaceFont.deriveFont(10.0f)
 
   /** Normal sized monospaced font. */
-  val normalFont = monospaceFont
+  val normalFont: Font = monospaceFont
 
   /** Large sized monospaced font. */
-  val largeFont = monospaceFont.deriveFont(14.0f)
+  val largeFont: Font = monospaceFont.deriveFont(14.0f)
 
   /** Dimensions for a character using the small font. */
-  val smallFontDims = dimensions(smallFont)
+  val smallFontDims: Dimensions = dimensions(smallFont)
 
   /** Dimensions for a character using the normal font. */
-  val normalFontDims = dimensions(normalFont)
+  val normalFontDims: Dimensions = dimensions(normalFont)
 
   /** Dimensions for a character using the large font. */
-  val largeFontDims = dimensions(largeFont)
+  val largeFontDims: Dimensions = dimensions(largeFont)
 
   /**
     * Minimum width required for text elements. Value was chosen to allow typical messages to
     * display with a reasonable level of wrapping.
     */
-  val minWidthForText = smallFontDims.width * "Warnings: abcdef".length
+  val minWidthForText: Int = smallFontDims.width * "Warnings: abcdef".length
 
   /**
     * Minimum width required for text elements. Value was chosen to allow the typical legend with
     * stats to show cleanly. It also keeps the cutoff below the level of sizes that are frequently
     * used in practice.
     */
-  val minWidthForStats = smallFontDims.width * 45
+  val minWidthForStats: Int = smallFontDims.width * 45
 
   /**
     * Determine the dimensions for a single character using `font`. It is assumed that the font

atlas-chart/src/main/scala/com/netflix/atlas/chart/graphics/Style.scala

@@ -43,5 +43,5 @@ case class Style(color: Color = Color.BLACK, stroke: Stroke = new BasicStroke(1.
 }
 
 object Style {
-  val default = Style()
+  val default: Style = Style()
 }

atlas-chart/src/main/scala/com/netflix/atlas/chart/graphics/Text.scala

@@ -42,7 +42,7 @@ case class Text(
 ) extends Element
     with VariableHeight {
 
-  lazy val dims = ChartSettings.dimensions(font)
+  lazy val dims: ChartSettings.Dimensions = ChartSettings.dimensions(font)
 
   def truncate(width: Int): Text = {
     val maxChars = (width - Text.rightPadding) / dims.width

atlas-chart/src/main/scala/com/netflix/atlas/chart/graphics/Ticks.scala

@@ -37,7 +37,7 @@ object Ticks {
   private val monthTimeFmt: DateTimeFormatter = DateTimeFormatter.ofPattern("MMM")
   private val yearTimeFmt: DateTimeFormatter = DateTimeFormatter.ofPattern("yyyy")
 
-  val timeBoundaries = List(
+  val timeBoundaries: List[(ChronoField, DateTimeFormatter)] = List(
     ChronoField.SECOND_OF_MINUTE -> DateTimeFormatter.ofPattern(":ss"),
     ChronoField.MINUTE_OF_HOUR   -> DateTimeFormatter.ofPattern("HH:mm"),
     ChronoField.HOUR_OF_DAY      -> DateTimeFormatter.ofPattern("HH:mm")

atlas-chart/src/main/scala/com/netflix/atlas/chart/graphics/ValueAxis.scala

@@ -291,7 +291,7 @@ case class RightValueAxis(plotDef: PlotDef, styles: Styles, min: Double, max: Do
 
 object ValueAxis {
 
-  val labelHeight = ChartSettings.normalFontDims.height
+  val labelHeight: Int = ChartSettings.normalFontDims.height
 
   /**
     * Width of value tick labels. The assumption is a monospace font with 7 characters. The 7 is
@@ -300,9 +300,9 @@ object ValueAxis {
     * - `[sign][3digits][decimal point][1digit][suffix]`: e.g., `-102.3K`
     * - `-1.0e-5`
     */
-  val tickLabelWidth = ChartSettings.smallFontDims.width * 7
+  val tickLabelWidth: Int = ChartSettings.smallFontDims.width * 7
 
   val tickMarkLength = 4
 
-  val minTickLabelHeight = ChartSettings.smallFontDims.height * 3
+  val minTickLabelHeight: Int = ChartSettings.smallFontDims.height * 3
 }

atlas-chart/src/main/scala/com/netflix/atlas/chart/model/TickLabelMode.java

@@ -28,17 +28,14 @@ public enum TickLabelMode {
   OFF,
 
   /**
-   * Use decimal metric prefixes for tick labels.
-   *
-   * https://en.wikipedia.org/wiki/Metric_prefix
+   * Use decimal <a href="https://en.wikipedia.org/wiki/Metric_prefix">metric prefixes</a> for
+   * tick labels.
    */
   DECIMAL,
 
   /**
-   * Use binary prefixes for tick labels. Typically only used for data in bytes such as disk
-   * sizes.
-   *
-   * https://en.wikipedia.org/wiki/Binary_prefix
+   * Use <a href="https://en.wikipedia.org/wiki/Binary_prefix">binary prefixes</a> for tick
+   * labels. Typically only used for data in bytes such as disk sizes.
    */
   BINARY,
 

atlas-chart/src/main/scala/com/netflix/atlas/chart/model/VisionType.java

@@ -19,7 +19,7 @@
 
 /**
  * Convert a color to simulate a type of color blindness for those with normal vision. Based on:
- * http://web.archive.org/web/20081014161121/http://www.colorjack.com/labs/colormatrix/
+ * <a href="http://web.archive.org/web/20081014161121/http://www.colorjack.com/labs/colormatrix/">colormatrix</a>.
  */
 public enum VisionType {
   normal(new double[] {

atlas-chart/src/main/scala/com/netflix/atlas/chart/util/GraphAssertions.scala

@@ -88,7 +88,7 @@ class GraphAssertions(goldenDir: String, targetDir: String, assert: (Any, Any) =
     </html>"""
 
     Using.resource(Streams.fileOut(new File(s"$targetDir/report.html"))) { out =>
-      out.write(report.toString.getBytes("UTF-8"))
+      out.write(report.getBytes("UTF-8"))
     }
   }
 

atlas-chart/src/main/scala/com/netflix/atlas/chart/util/PngImage.scala

@@ -210,8 +210,6 @@ object PngImage {
 
 case class PngImage(data: RenderedImage, metadata: Map[String, String] = Map.empty) {
 
-  type JList = java.util.List[String]
-
   def toByteArray: Array[Byte] = {
     val buffer = new ByteArrayOutputStream
     write(buffer)

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

@@ -216,7 +216,7 @@ class MemoryBlockStore(step: Long, blockSize: Int, numBlocks: Int) extends Block
   }
 
   override def toString: String = {
-    val buf = new StringBuilder
+    val buf = new java.lang.StringBuilder
     (0 until numBlocks).foreach { i =>
       buf.append(i.toString).append(" => ").append(blocks(i))
       if (i == currentPos) buf.append(" (current)")

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

@@ -180,7 +180,7 @@ sealed trait Block {
     * @param aggr  the aggregate value to read from the block
     */
   def get(pos: Int, aggr: Int = Block.Sum): Double = {
-    import java.lang.{Double as JDouble}
+    import java.lang.Double as JDouble
     val v = get(pos)
     (aggr: @scala.annotation.switch) match {
       case Block.Sum   => v
@@ -312,7 +312,7 @@ case class ArrayBlock(var start: Long, size: Int) extends MutableBlock {
     * @return  number of values that were changed as a result of the merge operation
     */
   def merge(b: Block): Int = {
-    import java.lang.{Double as JDouble}
+    import java.lang.Double as JDouble
     var changed = 0
     var i = 0
     while (i < size) {
@@ -353,7 +353,7 @@ case class ArrayBlock(var start: Long, size: Int) extends MutableBlock {
   }
 
   override def toString: String = {
-    val buf = new StringBuilder
+    val buf = new java.lang.StringBuilder
     buf.append("ArrayBlock(").append(start).append(",").append(size).append(",")
     buf.append("Array(").append(buffer.mkString(",")).append(")")
     buf.append(")")
@@ -383,7 +383,7 @@ object FloatArrayBlock {
   */
 case class FloatArrayBlock(start: Long, size: Int) extends Block {
 
-  val buffer = ArrayHelper.fill(size, Float.NaN)
+  val buffer: Array[Float] = ArrayHelper.fill(size, Float.NaN)
 
   def get(pos: Int): Double = buffer(pos).asInstanceOf[Double]
   val byteCount: Int = 2 + sizeOf(buffer)
@@ -411,7 +411,7 @@ case class FloatArrayBlock(start: Long, size: Int) extends Block {
   }
 
   override def toString: String = {
-    val buf = new StringBuilder
+    val buf = new java.lang.StringBuilder
     buf.append("FloatArrayBlock(").append(start).append(",").append(size).append(",")
     buf.append("Array(").append(buffer.mkString(",")).append(")")
     buf.append(")")
@@ -736,7 +736,7 @@ object SparseBlock {
       case v if v != v   => NaN
       case v if v == 0.0 => ZERO
       case v if v == 1.0 => ONE
-      case v             => UNDEFINED
+      case _             => UNDEFINED
     }
   }
 
@@ -797,7 +797,7 @@ case class SparseBlock(start: Long, indexes: Array[Byte], values: Array[Double])
   }
 
   override def toString: String = {
-    val buf = new StringBuilder
+    val buf = new java.lang.StringBuilder
     buf.append("SparseBlock(").append(start).append(",")
     buf.append("Array(").append(indexes.mkString(",")).append("),")
     buf.append("Array(").append(values.mkString(",")).append(")")

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

@@ -300,7 +300,7 @@ object DataExpr {
       val sorted = groups.sortWith(_._1 < _._1)
       val newData = sorted.flatMap {
         case (null, _) => Nil
-        case (k, Nil)  => List(TimeSeries.noData(query, context.step))
+        case (_, Nil)  => List(TimeSeries.noData(query, context.step))
         case (k, ts) =>
           val tags = ts.head.tags.filter(e => ks.contains(e._1))
           af.eval(context, ts).data.map { t =>

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

@@ -1009,7 +1009,7 @@ object MathExpr {
           // aggregate function. Modifications to the aggregate need to be represented
           // after the operation as part of the expression string. There are two
           // categories: offsets applied to the data function and group by.
-          val buffer = new StringBuilder
+          val buffer = new java.lang.StringBuilder
           buffer.append(s"$q,:$name")
           getOffset(evalExpr).foreach(d => buffer.append(s",$d,:offset"))
 
@@ -1018,7 +1018,7 @@ object MathExpr {
             buffer.append(grouping.mkString(",(,", ",", ",),:by"))
           }
 
-          buffer.toString()
+          buffer.toString
         case t: TimeSeriesExpr if groupingMatches =>
           // The passed in expression maybe the result of a rewrite to the display expression
           // that was not applied to the eval expression. If it changes the grouping, then it

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

@@ -270,7 +270,7 @@ object MathVocabulary extends Vocabulary {
       case StringListType(_) :: TimeSeriesType(t) :: _ if t.isGrouped =>
         // Multi-level group by with an implicit aggregate of :sum
         true
-      case StringListType(_) :: TimeSeriesType(t) :: _ =>
+      case StringListType(_) :: TimeSeriesType(_) :: _ =>
         // Default data or math aggregate group by applied across math operations
         true
     }

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

@@ -431,7 +431,7 @@ object QueryVocabulary extends Vocabulary {
     }
 
     protected def executor: PartialFunction[List[Any], List[Any]] = {
-      case Nil :: (k: String) :: s                  => Query.False :: s
+      case Nil :: (_: String) :: s                  => Query.False :: s
       case ((v: String) :: Nil) :: (k: String) :: s => Query.Equal(k, v) :: s
       case StringListType(vs) :: (k: String) :: s   => Query.In(k, vs) :: s
     }

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

@@ -26,7 +26,7 @@ object SummaryStats {
     var min = Double.PositiveInfinity
     var last = Double.NaN
 
-    ts.foreach(start, end) { (t, v) =>
+    ts.foreach(start, end) { (_, v) =>
       if (!v.isNaN) {
         total += v
         count += 1

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

@@ -53,7 +53,7 @@ trait TimeSeq {
     val length = ((end - start) / step).toInt
     val data = new Array[Double](length)
     var i = 0
-    foreach(start, end) { (t, v) =>
+    foreach(start, end) { (_, v) =>
       data(i) = v
       i += 1
     }
@@ -102,7 +102,7 @@ final class ArrayTimeSeq(
   def update(ts: TimeSeq)(op: BinaryOp): Unit = {
     require(step == ts.step, "step sizes must be the same")
     var i = 0
-    ts.foreach(start, end) { (t, v) =>
+    ts.foreach(start, end) { (_, v) =>
       data(i) = op(data(i), v)
       i += 1
     }
@@ -131,7 +131,7 @@ final class ArrayTimeSeq(
   }
 
   override def hashCode: Int = {
-    import java.lang.{Long as JLong}
+    import java.lang.Long as JLong
     val prime = 31
     var hc = prime
     hc = hc * prime + dsType.hashCode()

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

@@ -19,5 +19,4 @@ package object model {
 
   type UnaryOp = Double => Double
   type BinaryOp = (Double, Double) => Double
-  type TimeSeriesInput = Iterator[(String, TimeSeries)]
 }

atlas-core/src/main/scala/com/netflix/atlas/core/util/IsoDateTimeParser.scala

@@ -57,12 +57,12 @@ object IsoDateTimeParser {
     str match {
       case IsoDate(d)                  => s"${d}T00:00:00"
       case IsoDateZ(d, z)              => s"${d}T00:00:00${normalizeZone(z)}"
-      case IsoDateTimeHHMM(d)          => s"${d}:00"
-      case IsoDateTimeHHMMZ(d, z)      => s"${d}:00${normalizeZone(z)}"
-      case IsoDateTimeHHMMSS(d)        => s"${d}"
-      case IsoDateTimeHHMMSSZ(d, z)    => s"${d}${normalizeZone(z)}"
-      case IsoDateTimeHHMMSSmmm(d)     => s"${d}"
-      case IsoDateTimeHHMMSSmmmZ(d, z) => s"${d}${normalizeZone(z)}"
+      case IsoDateTimeHHMM(d)          => s"$d:00"
+      case IsoDateTimeHHMMZ(d, z)      => s"$d:00${normalizeZone(z)}"
+      case IsoDateTimeHHMMSS(d)        => d
+      case IsoDateTimeHHMMSSZ(d, z)    => s"$d${normalizeZone(z)}"
+      case IsoDateTimeHHMMSSmmm(d)     => d
+      case IsoDateTimeHHMMSSmmmZ(d, z) => s"$d${normalizeZone(z)}"
       case _                           => str
     }
   }

atlas-core/src/main/scala/com/netflix/atlas/core/util/PrimeFinder.java

@@ -20,7 +20,7 @@
 /**
  * Copied from the apache-mahout project.
  *
- * Not of interest for users; only for implementors of hashtables.
+ * <p>Not of interest for users; only for implementors of hashtables.
  * Used to keep hash table capacities prime numbers.
  *
  * <p>Choosing prime numbers as hash table capacities is a good idea to keep them working fast,
@@ -43,19 +43,19 @@ class PrimeFinder {
    * next element is a prime P2. P2 is the smallest prime for which holds: P2 >= 2*P1. The next element is P3, for which
    * the same holds with respect to P2, and so on.
    *
-   * Chunks are chosen such that for any desired capacity >= 1000 the list includes a prime number <= desired capacity *
+   * <p>Chunks are chosen such that for any desired capacity >= 1000 the list includes a prime number <= desired capacity *
    * 1.11 (11%). For any desired capacity >= 200 the list includes a prime number <= desired capacity * 1.16 (16%). For
    * any desired capacity >= 16 the list includes a prime number <= desired capacity * 1.21 (21%).
    *
-   * Therefore, primes can be retrieved which are quite close to any desired capacity, which in turn avoids wasting
+   * <p>Therefore, primes can be retrieved which are quite close to any desired capacity, which in turn avoids wasting
    * memory. For example, the list includes 1039,1117,1201,1277,1361,1439,1523,1597,1759,1907,2081. So if you need a
    * prime >= 1040, you will find a prime <= 1040*1.11=1154.
    *
-   * Chunks are chosen such that they are optimized for a hashtable growthfactor of 2.0; If your hashtable has such a
+   * <p>Chunks are chosen such that they are optimized for a hashtable growthfactor of 2.0; If your hashtable has such a
    * growthfactor then, after initially "rounding to a prime" upon hashtable construction, it will later expand to prime
    * capacities such that there exist no better primes.
    *
-   * In total these are about 32*10=320 numbers -> 1 KB of static memory needed. If you are stingy, then delete every
+   * <p>In total these are about 32*10=320 numbers -> 1 KB of static memory needed. If you are stingy, then delete every
    * second or fourth chunk.
    */