diff options
Diffstat (limited to 'kamon-core/src/main/scala/kamon/trace/SpanCodec.scala')
| -rw-r--r-- | kamon-core/src/main/scala/kamon/trace/SpanCodec.scala | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/kamon-core/src/main/scala/kamon/trace/SpanCodec.scala b/kamon-core/src/main/scala/kamon/trace/SpanCodec.scala new file mode 100644 index 00000000..e04ceb03 --- /dev/null +++ b/kamon-core/src/main/scala/kamon/trace/SpanCodec.scala @@ -0,0 +1,99 @@ +/* ========================================================================================= + * Copyright © 2013-2017 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.trace + +import java.net.{URLDecoder, URLEncoder} + +import kamon.Kamon +import kamon.context.{Codec, Context, TextMap} +import kamon.trace.SpanContext.SamplingDecision + + +object SpanCodec { + + class B3 extends Codec.ForEntry[TextMap] { + import B3.Headers + + override def encode(context: Context): TextMap = { + val span = context.get(Span.ContextKey) + val carrier = TextMap.Default() + + if(span.nonEmpty()) { + val spanContext = span.context + carrier.put(Headers.TraceIdentifier, urlEncode(spanContext.traceID.string)) + carrier.put(Headers.SpanIdentifier, urlEncode(spanContext.spanID.string)) + carrier.put(Headers.ParentSpanIdentifier, urlEncode(spanContext.parentID.string)) + + encodeSamplingDecision(spanContext.samplingDecision).foreach { samplingDecision => + carrier.put(Headers.Sampled, samplingDecision) + } + } + + carrier + } + + override def decode(carrier: TextMap, context: Context): Context = { + val identityProvider = Kamon.tracer.identityProvider + val traceID = carrier.get(Headers.TraceIdentifier) + .map(id => identityProvider.traceIdGenerator().from(urlDecode(id))) + .getOrElse(IdentityProvider.NoIdentifier) + + val spanID = carrier.get(Headers.SpanIdentifier) + .map(id => identityProvider.spanIdGenerator().from(urlDecode(id))) + .getOrElse(IdentityProvider.NoIdentifier) + + if(traceID != IdentityProvider.NoIdentifier && spanID != IdentityProvider.NoIdentifier) { + val parentID = carrier.get(Headers.ParentSpanIdentifier) + .map(id => identityProvider.spanIdGenerator().from(urlDecode(id))) + .getOrElse(IdentityProvider.NoIdentifier) + + val flags = carrier.get(Headers.Flags) + + val samplingDecision = flags.orElse(carrier.get(Headers.Sampled)) match { + case Some(sampled) if sampled == "1" => SamplingDecision.Sample + case Some(sampled) if sampled == "0" => SamplingDecision.DoNotSample + case _ => SamplingDecision.Unknown + } + + context.withKey(Span.ContextKey, Span.Remote(SpanContext(traceID, spanID, parentID, samplingDecision))) + + } else context + } + + private def encodeSamplingDecision(samplingDecision: SamplingDecision): Option[String] = samplingDecision match { + case SamplingDecision.Sample => Some("1") + case SamplingDecision.DoNotSample => Some("0") + case SamplingDecision.Unknown => None + } + + private def urlEncode(s: String): String = URLEncoder.encode(s, "UTF-8") + private def urlDecode(s: String): String = URLDecoder.decode(s, "UTF-8") + } + + object B3 { + + def apply(): B3 = + new B3() + + object Headers { + val TraceIdentifier = "X-B3-TraceId" + val ParentSpanIdentifier = "X-B3-ParentSpanId" + val SpanIdentifier = "X-B3-SpanId" + val Sampled = "X-B3-Sampled" + val Flags = "X-B3-Flags" + } + } +}
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