1 files changed, 49 insertions, 19 deletions

diff --git a/kamon-datadog/src/main/scala/kamon/datadog/DatadogMetricsSender.scala b/kamon-datadog/src/main/scala/kamon/datadog/DatadogMetricsSender.scala
index ec603b39..de4dc140 100644
--- a/kamon-datadog/src/main/scala/kamon/datadog/DatadogMetricsSender.scala
+++ b/kamon-datadog/src/main/scala/kamon/datadog/DatadogMetricsSender.scala
@@ -16,17 +16,18 @@
 
 package kamon.datadog
 
-import akka.actor.{ ActorSystem, Props, ActorRef, Actor }
-import akka.io.{ Udp, IO }
+import akka.actor.{ActorSystem, Props, ActorRef, Actor}
+import akka.io.{Udp, IO}
 import java.net.InetSocketAddress
 import akka.util.ByteString
 import kamon.metrics.Subscriptions.TickMetricSnapshot
 import kamon.metrics.MetricSnapshot.Measurement
-import kamon.metrics.InstrumentTypes.{ Counter, Gauge, Histogram, InstrumentType }
+import kamon.metrics.InstrumentTypes.{Counter, Gauge, Histogram, InstrumentType}
 import java.text.DecimalFormat
-import kamon.metrics.{ MetricIdentity, MetricGroupIdentity }
+import kamon.metrics.{MetricIdentity, MetricGroupIdentity}
+
+class DatadogMetricsSender(remote: InetSocketAddress, maxPacketSizeInBytes: Long) extends Actor with UdpExtensionProvider {
 
-class DatadogMetricsSender(remote: InetSocketAddress) extends Actor with UdpExtensionProvider {
   import context.system
 
   val appName = context.system.settings.config.getString("kamon.datadog.application-name")
@@ -45,53 +46,82 @@ class DatadogMetricsSender(remote: InetSocketAddress) extends Actor with UdpExte
   }
 
   def writeMetricsToRemote(tick: TickMetricSnapshot, udpSender: ActorRef): Unit = {
-    def flushToUDP(data: String): Unit = udpSender ! Udp.Send(ByteString(data), remote)
+    val dataBuilder = new MetricDataPacketBuilder(maxPacketSizeInBytes, udpSender, remote)
 
-    for (
+    for {
       (groupIdentity, groupSnapshot) ← tick.metrics;
       (metricIdentity, metricSnapshot) ← groupSnapshot.metrics
-    ) {
+    } {
+
+      val key = buildMetricName(groupIdentity, metricIdentity)
 
       for (measurement ← metricSnapshot.measurements) {
         val measurementData = formatMeasurement(groupIdentity, metricIdentity, measurement, metricSnapshot.instrumentType)
-        flushToUDP(measurementData)
+        dataBuilder.appendMeasurement(key, measurementData)
       }
     }
+    dataBuilder.flush()
   }
 
   def formatMeasurement(groupIdentity: MetricGroupIdentity, metricIdentity: MetricIdentity, measurement: Measurement,
                         instrumentType: InstrumentType): String = {
 
-    StringBuilder.newBuilder
-      .append(buildMetricName(groupIdentity, metricIdentity))
-      .append(":")
-      .append(buildMeasurementData(measurement, instrumentType))
+    StringBuilder.newBuilder.append(buildMeasurementData(measurement, instrumentType))
       .append(buildIdentificationTag(groupIdentity, metricIdentity))
       .result()
   }
 
   def buildMeasurementData(measurement: Measurement, instrumentType: InstrumentType): String = {
     def dataDogDMetricFormat(value: String, metricType: String, samplingRate: Double = 1D): String =
-      value + "|" + metricType + (if (samplingRate != 1D) "|@" + samplingRateFormat.format(samplingRate) else "")
+      s"$value|$metricType${(if (samplingRate != 1D) "|@" + samplingRateFormat.format(samplingRate) else "")}"
 
     instrumentType match {
       case Histogram ⇒ dataDogDMetricFormat(measurement.value.toString, "ms", (1D / measurement.count))
-      case Gauge     ⇒ dataDogDMetricFormat(measurement.value.toString, "g")
-      case Counter   ⇒ dataDogDMetricFormat(measurement.count.toString, "c")
+      case Gauge ⇒ dataDogDMetricFormat(measurement.value.toString, "g")
+      case Counter ⇒ dataDogDMetricFormat(measurement.count.toString, "c")
     }
   }
 
   def buildMetricName(groupIdentity: MetricGroupIdentity, metricIdentity: MetricIdentity): String =
-    appName + "." + groupIdentity.category.name + "." + metricIdentity.name
+    s"$appName.${groupIdentity.category.name}.${metricIdentity.name}"
 
   def buildIdentificationTag(groupIdentity: MetricGroupIdentity, metricIdentity: MetricIdentity): String =
-    "|#" + groupIdentity.category.name + ":" + groupIdentity.name
+    s"|#${groupIdentity.category.name}:${groupIdentity.name}"
 }
 
 object DatadogMetricsSender {
-  def props(remote: InetSocketAddress): Props = Props(new DatadogMetricsSender(remote))
+  def props(remote: InetSocketAddress, maxPacketSize: Long): Props = Props(new DatadogMetricsSender(remote, maxPacketSize))
 }
 
 trait UdpExtensionProvider {
   def udpExtension(implicit system: ActorSystem): ActorRef = IO(Udp)
 }
+
+class MetricDataPacketBuilder(maxPacketSizeInBytes: Long, udpSender: ActorRef, remote: InetSocketAddress) {
+  val metricSeparator = "\n"
+  val measurementSeparator = ":"
+  var lastKey = ""
+  var buffer = new StringBuilder()
+
+  def appendMeasurement(key: String, measurementData: String): Unit = {
+    val data = key + measurementSeparator + measurementData
+
+    if (fitsOnBuffer(metricSeparator + data)) {
+      val mSeparator = if (buffer.length > 0) metricSeparator else ""
+      buffer.append(mSeparator).append(data)
+    } else {
+      flushToUDP(buffer.toString())
+      buffer.clear()
+      buffer.append(data)
+    }
+  }
+
+  def fitsOnBuffer(data: String): Boolean = (buffer.length + data.length) <= maxPacketSizeInBytes
+
+  private def flushToUDP(data: String): Unit = udpSender ! Udp.Send(ByteString(data), remote)
+
+  def flush(): Unit = {
+    flushToUDP(buffer.toString)
+    buffer.clear()
+  }
+}