Add more numeric utilities to MilliSatoshi (#1103)

Add comparisons and postfix operators.
Update most of the codebase to leverage those.

eclair-core/src/main/scala/fr/acinq/eclair/CoinUtils.scala

@@ -17,14 +17,16 @@
 package fr.acinq.eclair
 
 import java.text.{DecimalFormat, NumberFormat}
+
 import fr.acinq.bitcoin.{Btc, BtcAmount, MilliBtc, Satoshi}
 import grizzled.slf4j.Logging
+
 import scala.util.{Failure, Success, Try}
 
 /**
-  * Internal UI utility class, useful for lossless conversion between BtcAmount.
-  * The issue being that Satoshi contains a Long amount and it can not be converted to MilliSatoshi without losing the decimal part.
-  */
+ * Internal UI utility class, useful for lossless conversion between BtcAmount.
+ * The issue being that Satoshi contains a Long amount and it can not be converted to MilliSatoshi without losing the decimal part.
+ */
 private sealed trait BtcAmountGUILossless {
   def amount_msat: Long
   def unit: CoinUnit
@@ -124,15 +126,15 @@ object CoinUtils extends Logging {
   }
 
   /**
-    * Converts a string amount denominated in a bitcoin unit to a Millisatoshi amount. The amount might be truncated if
-    * it has too many decimals because MilliSatoshi only accepts Long amount.
-    *
-    * @param amount numeric String, can be decimal.
-    * @param unit   bitcoin unit, can be milliSatoshi, Satoshi, Bits, milliBTC, BTC.
-    * @return       amount as a MilliSatoshi object.
-    * @throws NumberFormatException    if the amount parameter is not numeric.
-    * @throws IllegalArgumentException if the unit is not equals to milliSatoshi, Satoshi or milliBTC.
-    */
+   * Converts a string amount denominated in a bitcoin unit to a Millisatoshi amount. The amount might be truncated if
+   * it has too many decimals because MilliSatoshi only accepts Long amount.
+   *
+   * @param amount numeric String, can be decimal.
+   * @param unit   bitcoin unit, can be milliSatoshi, Satoshi, Bits, milliBTC, BTC.
+   * @return amount as a MilliSatoshi object.
+   * @throws NumberFormatException    if the amount parameter is not numeric.
+   * @throws IllegalArgumentException if the unit is not equals to milliSatoshi, Satoshi or milliBTC.
+   */
   @throws(classOf[NumberFormatException])
   @throws(classOf[IllegalArgumentException])
   def convertStringAmountToMsat(amount: String, unit: String): MilliSatoshi = {
@@ -152,13 +154,11 @@ object CoinUtils extends Logging {
   }
 
   def convertStringAmountToSat(amount: String, unit: String): Satoshi =
-   CoinUtils.convertStringAmountToMsat(amount, unit).truncateToSatoshi
+    CoinUtils.convertStringAmountToMsat(amount, unit).truncateToSatoshi
 
   /**
-    * Only BtcUnit, MBtcUnit, BitUnit, SatUnit and MSatUnit codes or label are supported.
-    * @param unit
-    * @return
-    */
+   * Only BtcUnit, MBtcUnit, BitUnit, SatUnit and MSatUnit codes or label are supported.
+   */
   def getUnitFromString(unit: String): CoinUnit = unit.toLowerCase() match {
     case u if u == MSatUnit.code || u == MSatUnit.label.toLowerCase() => MSatUnit
     case u if u == SatUnit.code || u == SatUnit.label.toLowerCase() => SatUnit
@@ -169,53 +169,53 @@ object CoinUtils extends Logging {
   }
 
   /**
-    * Converts BtcAmount to a GUI Unit (wrapper containing amount as a millisatoshi long)
-    *
-    * @param amount BtcAmount
-    * @param unit unit to convert to
-    * @return a GUICoinAmount
-    */
+   * Converts BtcAmount to a GUI Unit (wrapper containing amount as a millisatoshi long)
+   *
+   * @param amount BtcAmount
+   * @param unit   unit to convert to
+   * @return a GUICoinAmount
+   */
   private def convertAmountToGUIUnit(amount: BtcAmount, unit: CoinUnit): BtcAmountGUILossless = (amount, unit) match {
     // amount is msat, so no conversion required
-    case (a: MilliSatoshi, MSatUnit) => GUIMSat(a.amount * MSatUnit.factorToMsat)
-    case (a: MilliSatoshi, SatUnit) => GUISat(a.amount * MSatUnit.factorToMsat)
-    case (a: MilliSatoshi, BitUnit) => GUIBits(a.amount * MSatUnit.factorToMsat)
-    case (a: MilliSatoshi, MBtcUnit) => GUIMBtc(a.amount * MSatUnit.factorToMsat)
-    case (a: MilliSatoshi, BtcUnit) => GUIBtc(a.amount * MSatUnit.factorToMsat)
+    case (a: MilliSatoshi, MSatUnit) => GUIMSat(a.toLong * MSatUnit.factorToMsat)
+    case (a: MilliSatoshi, SatUnit) => GUISat(a.toLong * MSatUnit.factorToMsat)
+    case (a: MilliSatoshi, BitUnit) => GUIBits(a.toLong * MSatUnit.factorToMsat)
+    case (a: MilliSatoshi, MBtcUnit) => GUIMBtc(a.toLong * MSatUnit.factorToMsat)
+    case (a: MilliSatoshi, BtcUnit) => GUIBtc(a.toLong * MSatUnit.factorToMsat)
 
     // amount is satoshi, convert sat -> msat
-    case (a: Satoshi, MSatUnit) => GUIMSat(a.amount * SatUnit.factorToMsat)
-    case (a: Satoshi, SatUnit) => GUISat(a.amount * SatUnit.factorToMsat)
-    case (a: Satoshi, BitUnit) => GUIBits(a.amount * SatUnit.factorToMsat)
-    case (a: Satoshi, MBtcUnit) => GUIMBtc(a.amount * SatUnit.factorToMsat)
-    case (a: Satoshi, BtcUnit) => GUIBtc(a.amount * SatUnit.factorToMsat)
+    case (a: Satoshi, MSatUnit) => GUIMSat(a.toLong * SatUnit.factorToMsat)
+    case (a: Satoshi, SatUnit) => GUISat(a.toLong * SatUnit.factorToMsat)
+    case (a: Satoshi, BitUnit) => GUIBits(a.toLong * SatUnit.factorToMsat)
+    case (a: Satoshi, MBtcUnit) => GUIMBtc(a.toLong * SatUnit.factorToMsat)
+    case (a: Satoshi, BtcUnit) => GUIBtc(a.toLong * SatUnit.factorToMsat)
 
     // amount is mbtc
-    case (a: MilliBtc, MSatUnit) => GUIMSat((a.amount * MBtcUnit.factorToMsat).toLong)
-    case (a: MilliBtc, SatUnit) => GUISat((a.amount * MBtcUnit.factorToMsat).toLong)
-    case (a: MilliBtc, BitUnit) => GUIBits((a.amount * MBtcUnit.factorToMsat).toLong)
-    case (a: MilliBtc, MBtcUnit) => GUIMBtc((a.amount * MBtcUnit.factorToMsat).toLong)
-    case (a: MilliBtc, BtcUnit) => GUIBtc((a.amount * MBtcUnit.factorToMsat).toLong)
+    case (a: MilliBtc, MSatUnit) => GUIMSat((a.toBigDecimal * MBtcUnit.factorToMsat).toLong)
+    case (a: MilliBtc, SatUnit) => GUISat((a.toBigDecimal * MBtcUnit.factorToMsat).toLong)
+    case (a: MilliBtc, BitUnit) => GUIBits((a.toBigDecimal * MBtcUnit.factorToMsat).toLong)
+    case (a: MilliBtc, MBtcUnit) => GUIMBtc((a.toBigDecimal * MBtcUnit.factorToMsat).toLong)
+    case (a: MilliBtc, BtcUnit) => GUIBtc((a.toBigDecimal * MBtcUnit.factorToMsat).toLong)
 
     // amount is mbtc
-    case (a: Btc, MSatUnit) => GUIMSat((a.amount * BtcUnit.factorToMsat).toLong)
-    case (a: Btc, SatUnit) => GUISat((a.amount * BtcUnit.factorToMsat).toLong)
-    case (a: Btc, BitUnit) => GUIBits((a.amount * BtcUnit.factorToMsat).toLong)
-    case (a: Btc, MBtcUnit) => GUIMBtc((a.amount * BtcUnit.factorToMsat).toLong)
-    case (a: Btc, BtcUnit) => GUIBtc((a.amount * BtcUnit.factorToMsat).toLong)
+    case (a: Btc, MSatUnit) => GUIMSat((a.toBigDecimal * BtcUnit.factorToMsat).toLong)
+    case (a: Btc, SatUnit) => GUISat((a.toBigDecimal * BtcUnit.factorToMsat).toLong)
+    case (a: Btc, BitUnit) => GUIBits((a.toBigDecimal * BtcUnit.factorToMsat).toLong)
+    case (a: Btc, MBtcUnit) => GUIMBtc((a.toBigDecimal * BtcUnit.factorToMsat).toLong)
+    case (a: Btc, BtcUnit) => GUIBtc((a.toBigDecimal * BtcUnit.factorToMsat).toLong)
 
-    case (a, _) =>
+    case (_, _) =>
       throw new IllegalArgumentException(s"unhandled conversion from $amount to $unit")
   }
 
   /**
-    * Converts the amount to the user preferred unit and returns a localized formatted String.
-    * This method is useful for read only displays.
-    *
-    * @param amount BtcAmount
-    * @param withUnit if true, append the user unit shortLabel (mBTC, BTC, mSat...)
-    * @return formatted amount
-    */
+   * Converts the amount to the user preferred unit and returns a localized formatted String.
+   * This method is useful for read only displays.
+   *
+   * @param amount   BtcAmount
+   * @param withUnit if true, append the user unit shortLabel (mBTC, BTC, mSat...)
+   * @return formatted amount
+   */
   def formatAmountInUnit(amount: BtcAmount, unit: CoinUnit, withUnit: Boolean = false): String = {
     val formatted = COIN_FORMAT.format(rawAmountInUnit(amount, unit))
     if (withUnit) s"$formatted ${unit.shortLabel}" else formatted
@@ -227,14 +227,14 @@ object CoinUtils extends Logging {
   }
 
   /**
-    * Converts the amount to the user preferred unit and returns the BigDecimal value.
-    * This method is useful to feed numeric text input without formatting.
-    *
-    * Returns -1 if the given amount can not be converted.
-    *
-    * @param amount BtcAmount
-    * @return BigDecimal value of the BtcAmount
-    */
+   * Converts the amount to the user preferred unit and returns the BigDecimal value.
+   * This method is useful to feed numeric text input without formatting.
+   *
+   * Returns -1 if the given amount can not be converted.
+   *
+   * @param amount BtcAmount
+   * @return BigDecimal value of the BtcAmount
+   */
   def rawAmountInUnit(amount: BtcAmount, unit: CoinUnit): BigDecimal = Try(convertAmountToGUIUnit(amount, unit) match {
     case a: BtcAmountGUILossless => BigDecimal(a.amount_msat) / a.unit.factorToMsat
     case a => throw new IllegalArgumentException(s"unhandled unit $a")
@@ -245,5 +245,5 @@ object CoinUtils extends Logging {
       -1
   }
 
-  def rawAmountInUnit(msat: MilliSatoshi, unit: CoinUnit): BigDecimal = BigDecimal(msat.amount) / unit.factorToMsat
+  def rawAmountInUnit(msat: MilliSatoshi, unit: CoinUnit): BigDecimal = BigDecimal(msat.toLong) / unit.factorToMsat
 }

eclair-core/src/main/scala/fr/acinq/eclair/Eclair.scala

@@ -128,7 +128,7 @@ class EclairImpl(appKit: Kit) extends Eclair {
     (appKit.switchboard ? Peer.OpenChannel(
       remoteNodeId = nodeId,
       fundingSatoshis = fundingAmount,
-      pushMsat = pushAmount_opt.getOrElse(MilliSatoshi(0)),
+      pushMsat = pushAmount_opt.getOrElse(0 msat),
       fundingTxFeeratePerKw_opt = fundingFeerateSatByte_opt.map(feerateByte2Kw),
       channelFlags = flags_opt.map(_.toByte),
       timeout_opt = Some(openTimeout))).mapTo[String]

eclair-core/src/main/scala/fr/acinq/eclair/MilliSatoshi.scala

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2019 ACINQ SAS
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package fr.acinq.eclair
+
+import fr.acinq.bitcoin.{Btc, BtcAmount, MilliBtc, Satoshi, btc2satoshi, millibtc2satoshi}
+
+/**
+ * Created by t-bast on 22/08/2019.
+ */
+
+/**
+ * One MilliSatoshi is a thousand of a Satoshi, the smallest unit usable in bitcoin
+ */
+case class MilliSatoshi(private val underlying: Long) extends Ordered[MilliSatoshi] {
+
+  // @formatter:off
+  def +(other: MilliSatoshi) = MilliSatoshi(underlying + other.underlying)
+  def +(other: BtcAmount) = MilliSatoshi(underlying + other.toMilliSatoshi.underlying)
+  def -(other: MilliSatoshi) = MilliSatoshi(underlying - other.underlying)
+  def -(other: BtcAmount) = MilliSatoshi(underlying - other.toMilliSatoshi.underlying)
+  def *(m: Long) = MilliSatoshi(underlying * m)
+  def *(m: Double) = MilliSatoshi((underlying * m).toLong)
+  def /(d: Long) = MilliSatoshi(underlying / d)
+  def unary_-() = MilliSatoshi(-underlying)
+
+  override def compare(other: MilliSatoshi): Int = underlying.compareTo(other.underlying)
+  // Since BtcAmount is a sealed trait that MilliSatoshi cannot extend, we need to redefine comparison operators.
+  def compare(other: BtcAmount): Int = compare(other.toMilliSatoshi)
+  def <=(other: BtcAmount): Boolean = compare(other) <= 0
+  def >=(other: BtcAmount): Boolean = compare(other) >= 0
+  def <(other: BtcAmount): Boolean = compare(other) < 0
+  def >(other: BtcAmount): Boolean = compare(other) > 0
+
+  // We provide asymmetric min/max functions to provide more control on the return type.
+  def max(other: MilliSatoshi): MilliSatoshi = if (this > other) this else other
+  def max(other: BtcAmount): MilliSatoshi = if (this > other) this else other.toMilliSatoshi
+  def min(other: MilliSatoshi): MilliSatoshi = if (this < other) this else other
+  def min(other: BtcAmount): MilliSatoshi = if (this < other) this else other.toMilliSatoshi
+
+  def truncateToSatoshi: Satoshi = Satoshi(underlying / 1000)
+  def toLong: Long = underlying
+  override def toString = s"$underlying msat"
+  // @formatter:on
+
+}
+
+object MilliSatoshi {
+
+  private def satoshi2millisatoshi(input: Satoshi): MilliSatoshi = MilliSatoshi(input.toLong * 1000L)
+
+  def toMilliSatoshi(amount: BtcAmount): MilliSatoshi = amount match {
+    case sat: Satoshi => satoshi2millisatoshi(sat)
+    case millis: MilliBtc => satoshi2millisatoshi(millibtc2satoshi(millis))
+    case bitcoin: Btc => satoshi2millisatoshi(btc2satoshi(bitcoin))
+  }
+
+}

eclair-core/src/main/scala/fr/acinq/eclair/api/JsonSerializers.scala

@@ -58,11 +58,11 @@ class UInt64Serializer extends CustomSerializer[UInt64](format => ({ null }, {
 }))
 
 class SatoshiSerializer extends CustomSerializer[Satoshi](format => ({ null }, {
-  case x: Satoshi => JInt(x.amount)
+  case x: Satoshi => JInt(x.toLong)
 }))
 
 class MilliSatoshiSerializer extends CustomSerializer[MilliSatoshi](format => ({ null }, {
-  case x: MilliSatoshi => JInt(x.amount)
+  case x: MilliSatoshi => JInt(x.toLong)
 }))
 
 class CltvExpirySerializer extends CustomSerializer[CltvExpiry](format => ({ null }, {
@@ -124,7 +124,7 @@ class OutPointKeySerializer extends CustomKeySerializer[OutPoint](format => ({ n
 }))
 
 class InputInfoSerializer extends CustomSerializer[InputInfo](format => ({ null }, {
-  case x: InputInfo => JObject(("outPoint", JString(s"${x.outPoint.txid}:${x.outPoint.index}")), ("amountSatoshis", JInt(x.txOut.amount.amount)))
+  case x: InputInfo => JObject(("outPoint", JString(s"${x.outPoint.txid}:${x.outPoint.index}")), ("amountSatoshis", JInt(x.txOut.amount.toLong)))
 }))
 
 class ColorSerializer extends CustomSerializer[Color](format => ({ null }, {