! datadog: first commit of datadog integration module

1 files changed, 124 insertions, 0 deletions

diff --git a/kamon-datadog/src/main/scala/kamon/datadog/DatadogMetricsSender.scala b/kamon-datadog/src/main/scala/kamon/datadog/DatadogMetricsSender.scala
new file mode 100644
index 00000000..9d7b34e6
--- /dev/null
+++ b/kamon-datadog/src/main/scala/kamon/datadog/DatadogMetricsSender.scala
@@ -0,0 +1,124 @@
+/*
+ * =========================================================================================
+ * Copyright © 2013-2014 the kamon project <http://kamon.io/>
+ *
+ * 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 kamon.datadog
+
+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 java.text.DecimalFormat
+
+class DatadogMetricsSender(remote: InetSocketAddress, maxPacketSizeInBytes: Long) extends Actor with UdpExtensionProvider {
+  import context.system
+
+  val metricKeyGenerator = new SimpleMetricKeyGenerator(context.system.settings.config)
+  val samplingRateFormat = new DecimalFormat()
+  samplingRateFormat.setMaximumFractionDigits(128) // Absurdly high, let the other end loss precision if it needs to.
+
+  udpExtension ! Udp.SimpleSender
+
+  def receive = {
+    case Udp.SimpleSenderReady ⇒
+      context.become(ready(sender))
+  }
+
+  def ready(udpSender: ActorRef): Receive = {
+    case tick: TickMetricSnapshot ⇒ writeMetricsToRemote(tick, udpSender)
+  }
+
+  def writeMetricsToRemote(tick: TickMetricSnapshot, udpSender: ActorRef): Unit = {
+    val dataBuilder = new MetricDataPacketBuilder(maxPacketSizeInBytes, udpSender, remote)
+
+    for (
+      (groupIdentity, groupSnapshot) ← tick.metrics;
+      (metricIdentity, metricSnapshot) ← groupSnapshot.metrics
+    ) {
+
+      val key = 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): String = {
+    def statsDMetricFormat(value: String, metricType: String, samplingRate: Double = 1D): String =
+      value + "|" + metricType + (if (samplingRate != 1D) "|@" + samplingRateFormat.format(samplingRate) else "")
+
+    instrumentType match {
+      case Histogram ⇒ statsDMetricFormat(measurement.value.toString, "ms", (1D / measurement.count))
+      case Gauge     ⇒ statsDMetricFormat(measurement.value.toString, "g")
+      case Counter   ⇒ "" // TODO: Need to decide how to report counters, when we have them!
+    }
+  }
+}
+
+object DatadogMetricsSender {
+  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 = {
+    if (key == lastKey) {
+      val dataWithoutKey = measurementSeparator + measurementData
+      if (fitsOnBuffer(dataWithoutKey))
+        buffer.append(dataWithoutKey)
+      else {
+        flushToUDP(buffer.toString())
+        buffer.clear()
+        buffer.append(key).append(dataWithoutKey)
+      }
+    } else {
+      lastKey = key
+      val dataWithoutSeparator = key + measurementSeparator + measurementData
+      if (fitsOnBuffer(metricSeparator + dataWithoutSeparator)) {
+        val mSeparator = if (buffer.length > 0) metricSeparator else ""
+        buffer.append(mSeparator).append(dataWithoutSeparator)
+      } else {
+        flushToUDP(buffer.toString())
+        buffer.clear()
+        buffer.append(dataWithoutSeparator)
+      }
+    }
+  }
+
+  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()
+  }
+}