1 files changed, 75 insertions, 16 deletions

diff --git a/kamon-statsd/src/main/scala/kamon/statsd/StatsDMetricsSender.scala b/kamon-statsd/src/main/scala/kamon/statsd/StatsDMetricsSender.scala
index 63b1a53a..60404d7e 100644
--- a/kamon-statsd/src/main/scala/kamon/statsd/StatsDMetricsSender.scala
+++ b/kamon-statsd/src/main/scala/kamon/statsd/StatsDMetricsSender.scala
@@ -16,20 +16,23 @@
 
 package kamon.statsd
 
-import akka.actor.{ Props, ActorRef, Actor }
+import akka.actor.{ ActorSystem, Props, ActorRef, Actor }
 import akka.io.{ Udp, IO }
 import java.net.InetSocketAddress
 import akka.util.ByteString
 import kamon.Kamon
-import scala.annotation.tailrec
+import kamon.metrics.Subscriptions.TickMetricSnapshot
+import kamon.metrics.MetricSnapshot.Measurement
+import kamon.metrics.InstrumentTypes.{ Counter, Gauge, Histogram, InstrumentType }
 
-class StatsDMetricsSender extends Actor {
+class StatsDMetricsSender extends Actor with UdpExtensionProvider {
   import context.system
 
   val statsDExtension = Kamon(StatsD)
   val remote = new InetSocketAddress(statsDExtension.hostname, statsDExtension.port)
+  val metricKeyGenerator = new SimpleMetricKeyGenerator(context.system.settings.config)
 
-  IO(Udp) ! Udp.SimpleSender
+  udpExtension ! Udp.SimpleSender
 
   def receive = {
     case Udp.SimpleSenderReady ⇒
@@ -37,27 +40,83 @@ class StatsDMetricsSender extends Actor {
   }
 
   def ready(udpSender: ActorRef): Receive = {
-    case StatsD.MetricBatch(metrics) ⇒ sendMetricsToRemote(metrics, ByteString.empty, udpSender)
+    case tick: TickMetricSnapshot ⇒ writeMetricsToRemote(tick, udpSender)
   }
 
-  @tailrec final def sendMetricsToRemote(metrics: Iterable[StatsD.Metric], buffer: ByteString, udpSender: ActorRef): Unit = {
-    def flushToRemote(data: ByteString, udpSender: ActorRef): Unit = udpSender ! Udp.Send(data, remote)
+  def writeMetricsToRemote(tick: TickMetricSnapshot, udpSender: ActorRef): Unit = {
+    val dataBuilder = new MetricDataPacketBuilder(statsDExtension.maxPacketSize, udpSender, remote)
 
-    if (metrics.isEmpty)
-      flushToRemote(buffer, udpSender)
-    else {
-      val headMetricData = metrics.head.toByteString(includeTrailingNewline = true)
+    for (
+      (groupIdentity, groupSnapshot) ← tick.metrics;
+      (metricIdentity, metricSnapshot) ← groupSnapshot.metrics
+    ) {
 
-      if (buffer.size + headMetricData.size > statsDExtension.maxPacketSize) {
-        flushToRemote(buffer, udpSender)
-        sendMetricsToRemote(metrics.tail, headMetricData, udpSender)
-      } else {
-        sendMetricsToRemote(metrics.tail, buffer ++ headMetricData, udpSender)
+      val key = ByteString(metricKeyGenerator.generateKey(groupIdentity, metricIdentity))
+
+      for (measurement ← metricSnapshot.measurements) {
+        val measurementData = encodeMeasurement(measurement, metricSnapshot.instrumentType)
+        dataBuilder.appendMeasurement(key, measurementData)
       }
     }
+
+    dataBuilder.flush()
+  }
+
+  def encodeMeasurement(measurement: Measurement, instrumentType: InstrumentType): ByteString = {
+    def statsDMetricFormat(value: String, metricType: String, samplingRate: Double = 1D): ByteString =
+      ByteString(value + "|" + metricType + (if (samplingRate != 1D) "|@" + samplingRate else ""))
+
+    instrumentType match {
+      case Histogram ⇒ statsDMetricFormat(measurement.value.toString, "ms", (1D / measurement.count))
+      case Gauge     ⇒ statsDMetricFormat(measurement.value.toString, "g")
+      case Counter   ⇒ ByteString.empty // TODO: Need to decide how to report counters, when we have them!
+    }
   }
 }
 
 object StatsDMetricsSender {
   def props: Props = Props[StatsDMetricsSender]
+}
+
+trait UdpExtensionProvider {
+  def udpExtension(implicit system: ActorSystem): ActorRef = IO(Udp)
+}
+
+class MetricDataPacketBuilder(maxPacketSize: Int, udpSender: ActorRef, remote: InetSocketAddress) {
+  val metricSeparator = ByteString("\n")
+  val measurementSeparator = ByteString(":")
+
+  var lastKey = ByteString.empty
+  var buffer = ByteString.empty
+
+  def appendMeasurement(key: ByteString, measurementData: ByteString): Unit = {
+    if (key == lastKey) {
+      val dataWithoutKey = measurementSeparator ++ measurementData
+      if (fitsOnBuffer(dataWithoutKey))
+        buffer = buffer ++ dataWithoutKey
+      else {
+        flushToUDP(buffer)
+        buffer = key ++ dataWithoutKey
+      }
+    } else {
+      lastKey = key
+      val dataWithoutSeparator = key ++ measurementSeparator ++ measurementData
+      if (fitsOnBuffer(metricSeparator ++ dataWithoutSeparator)) {
+        val mSeparator = if (buffer.length > 0) metricSeparator else ByteString.empty
+        buffer = buffer ++ mSeparator ++ dataWithoutSeparator
+      } else {
+        flushToUDP(buffer)
+        buffer = dataWithoutSeparator
+      }
+    }
+  }
+
+  def fitsOnBuffer(bs: ByteString): Boolean = (buffer.length + bs.length) <= maxPacketSize
+
+  private def flushToUDP(bytes: ByteString): Unit = udpSender ! Udp.Send(bytes, remote)
+
+  def flush(): Unit = {
+    flushToUDP(buffer)
+    buffer = ByteString.empty
+  }
 }
\ No newline at end of file