Merge pull request #3324 from isaacl/bigDecimalTruncates

Use BigDecimal for json precision

modules/chess

@@ -1 +1 @@
-Subproject commit 046e2ff215754193195e28a0cdd1d03c33b3ab52
+Subproject commit 4432570caf88593709371a85671c465d3b8268a5

modules/common/src/main/Maths.scala

@@ -32,9 +32,8 @@ object Maths {
     else n toDouble upper.head
   }
 
-  def truncateAt(n: Double, p: Int): Double = {
-    val s = math.pow(10, p)
-    (math floor n * s) / s
+  def roundAt(n: Double, p: Int): BigDecimal = {
+    BigDecimal(n).setScale(p, BigDecimal.RoundingMode.HALF_UP)
   }
 
   def toInt(l: Long): Int = l.min(Int.MaxValue).max(Int.MinValue).toInt

modules/game/src/main/Event.scala

@@ -8,7 +8,6 @@ import chess.variant.Crazyhouse
 import chess.{ Centis, PromotableRole, Pos, Color, Situation, Move => ChessMove, Drop => ChessDrop, Clock => ChessClock, Status }
 import JsonView._
 import lila.chat.{ UserLine, PlayerLine }
-import lila.common.Maths.truncateAt
 
 sealed trait Event {
   def typ: String
@@ -264,20 +263,19 @@ object Event {
 
   sealed trait ClockEvent extends Event
 
-  case class Clock(white: Float, black: Float, nextLagComp: Option[Centis] = None) extends ClockEvent {
+  case class Clock(white: Centis, black: Centis, nextLagComp: Option[Centis] = None) extends ClockEvent {
     def typ = "clock"
     def data = Json.obj(
-      "white" -> truncateAt(white, 2),
-      "black" -> truncateAt(black, 2)
+      "white" -> white.toSeconds,
+      "black" -> black.toSeconds
     ).add("lag" -> nextLagComp.collect { case Centis(c) if c > 1 => c })
   }
   object Clock {
     def apply(clock: ChessClock): Clock = Clock(
-      clock remainingTime Color.White toSeconds,
-      clock remainingTime Color.Black toSeconds,
+      clock remainingTime Color.White,
+      clock remainingTime Color.Black,
       clock lagCompEstimate clock.color
     )
-    def tenths(white: Int, black: Int): Clock = Clock(white.toFloat / 10, black.toFloat / 10)
   }
 
   case class Berserk(color: Color) extends Event {

modules/game/src/main/JsonView.scala

@@ -80,7 +80,6 @@ object JsonView {
   }
 
   implicit val clockWriter: OWrites[Clock] = OWrites { c =>
-    import lila.common.Maths.truncateAt
     Json.obj(
       "running" -> c.isRunning,
       "initial" -> c.limitSeconds,

modules/perfStat/src/main/JsonView.scala

@@ -51,7 +51,7 @@ final class JsonView(getLightUser: LightUser.GetterSync) {
 
 object JsonView {
 
-  private def truncate(v: Double, depth: Int = 2) = lila.common.Maths.truncateAt(v, depth)
+  private def round(v: Double, depth: Int = 2) = lila.common.Maths.roundAt(v, depth)
 
   private val isoFormatter = ISODateTimeFormat.dateTime
   private implicit val dateWriter: Writes[DateTime] = Writes { d =>
@@ -62,9 +62,9 @@ object JsonView {
   }
   implicit val glickoWriter: OWrites[Glicko] = OWrites { p =>
     Json.obj(
-      "rating" -> truncate(p.rating),
-      "deviation" -> truncate(p.deviation),
-      "volatility" -> truncate(p.volatility, 3),
+      "rating" -> round(p.rating),
+      "deviation" -> round(p.deviation),
+      "volatility" -> round(p.volatility, 3),
       "provisional" -> p.provisional
     )
   }
@@ -72,7 +72,7 @@ object JsonView {
     Json.obj("glicko" -> p.glicko, "nb" -> p.nb, "progress" -> p.progress)
   }
   private implicit val avgWriter: Writes[Avg] = Writes { a =>
-    JsNumber(truncate(a.avg))
+    JsNumber(round(a.avg))
   }
   implicit val perfTypeWriter: OWrites[PerfType] = OWrites { pt =>
     Json.obj(

modules/slack/src/main/SlackApi.scala

@@ -50,7 +50,7 @@ final class SlackApi(
       if (event.username == "Anonymous") "Anonymous"
       else s"lichess.org/@/${event.username}"
 
-    private def amount(cents: Int) = s"$$${lila.common.Maths.truncateAt(cents / 100d, 2)}"
+    private def amount(cents: Int) = s"$$${BigDecimal(cents, 2)}"
   }
 
   def publishEvent(event: Event): Funit = event match {