/*
* =========================================================================================
* 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.statsd
import akka.actor.{ ActorSystem, Props, ActorRef, Actor }
import akka.io.{ Udp, IO }
import java.net.InetSocketAddress
import akka.util.ByteString
import kamon.metric.Subscriptions.TickMetricSnapshot
import java.text.{ DecimalFormatSymbols, DecimalFormat }
import java.util.Locale
import kamon.metric.instrument.{ Counter, Histogram }
class StatsDMetricsSender(remote: InetSocketAddress, maxPacketSizeInBytes: Long, metricKeyGenerator: StatsD.MetricKeyGenerator)
extends Actor with UdpExtensionProvider {
import context.system
val symbols = DecimalFormatSymbols.getInstance(Locale.US)
symbols.setDecimalSeparator('.') // Just in case there is some weird locale config we are not aware of.
// Absurdly high number of decimal digits, let the other end lose precision if it needs to.
val samplingRateFormat = new DecimalFormat("#.################################################################", symbols)
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 packetBuilder = new MetricDataPacketBuilder(maxPacketSizeInBytes, udpSender, remote)
for (
(groupIdentity, groupSnapshot) ← tick.metrics;
(metricIdentity, metricSnapshot) ← groupSnapshot.metrics
) {
val key = metricKeyGenerator.generateKey(groupIdentity, metricIdentity)
metricSnapshot match {
case hs: Histogram.Snapshot ⇒
hs.recordsIterator.foreach { record ⇒
packetBuilder.appendMeasurement(key, encodeStatsDTimer(record.level, record.count))
}
case cs: Counter.Snapshot ⇒
packetBuilder.appendMeasurement(key, encodeStatsDCounter(cs.count))
}
}
packetBuilder.flush()
}
def encodeStatsDTimer(level: Long, count: Long): String = {
val samplingRate: Double = 1D / count
level.toString + "|ms" + (if (samplingRate != 1D) "|@" + samplingRateFormat.format(samplingRate) else "")
}
def encodeStatsDCounter(count: Long): String = count.toString + "|c"
}
object StatsDMetricsSender {
def props(remote: InetSocketAddress, maxPacketSize: Long, metricKeyGenerator: StatsD.MetricKeyGenerator): Props =
Props(new StatsDMetricsSender(remote, maxPacketSize, metricKeyGenerator))
}
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()
}
}