introduce types for Span tags

4 files changed, 59 insertions, 16 deletions

diff --git a/kamon-core/src/main/scala/kamon/trace/ActiveSpan.scala b/kamon-core/src/main/scala/kamon/trace/ActiveSpan.scala
index 3753cd7e..68ef2254 100644
--- a/kamon-core/src/main/scala/kamon/trace/ActiveSpan.scala
+++ b/kamon-core/src/main/scala/kamon/trace/ActiveSpan.scala
@@ -37,6 +37,12 @@ object ActiveSpan {
     override def addSpanTag(key: String, value: String): Span =
       wrappedSpan.addSpanTag(key, value)
 
+    override def addSpanTag(key: String, value: Long): Span =
+      wrappedSpan.addSpanTag(key, value)
+
+    override def addSpanTag(key: String, value: Boolean): Span =
+      wrappedSpan.addSpanTag(key, value)
+
     override def addMetricTag(key: String, value: String): Span =
       wrappedSpan.addMetricTag(key, value)
 
diff --git a/kamon-core/src/main/scala/kamon/trace/Sampler.scala b/kamon-core/src/main/scala/kamon/trace/Sampler.scala
index e2aefe22..3f366175 100644
--- a/kamon-core/src/main/scala/kamon/trace/Sampler.scala
+++ b/kamon-core/src/main/scala/kamon/trace/Sampler.scala
@@ -19,7 +19,7 @@ import java.util.concurrent.ThreadLocalRandom
 import kamon.trace.SpanContext.SamplingDecision
 
 trait Sampler {
-  def decide(operationName: String, builderTags: Map[String, String]): SamplingDecision
+  def decide(operationName: String, builderTags: Map[String, Span.TagValue]): SamplingDecision
 }
 
 object Sampler {
@@ -37,7 +37,7 @@ object Sampler {
   }
 
   class Constant(decision: SamplingDecision) extends Sampler {
-    override def decide(operationName: String, builderTags: Map[String, String]): SamplingDecision = decision
+    override def decide(operationName: String, builderTags: Map[String, Span.TagValue]): SamplingDecision = decision
 
     override def toString: String =
       s"Sampler.Constant(decision = $decision)"
@@ -47,7 +47,7 @@ object Sampler {
     val upperBoundary = Long.MaxValue * probability
     val lowerBoundary = -upperBoundary
 
-    override def decide(operationName: String, builderTags: Map[String, String]): SamplingDecision = {
+    override def decide(operationName: String, builderTags: Map[String, Span.TagValue]): SamplingDecision = {
       val random = ThreadLocalRandom.current().nextLong()
       if(random >= lowerBoundary && random <= upperBoundary) SamplingDecision.Sample else SamplingDecision.DoNotSample
     }
diff --git a/kamon-core/src/main/scala/kamon/trace/Span.scala b/kamon-core/src/main/scala/kamon/trace/Span.scala
index ffe7bed7..ce09a36e 100644
--- a/kamon-core/src/main/scala/kamon/trace/Span.scala
+++ b/kamon-core/src/main/scala/kamon/trace/Span.scala
@@ -35,6 +35,10 @@ trait BaseSpan {
 
   def addSpanTag(key: String, value: String): Span
 
+  def addSpanTag(key: String, value: Long): Span
+
+  def addSpanTag(key: String, value: Boolean): Span
+
   def addMetricTag(key: String, value: String): Span
 
   def addBaggage(key: String, value: String): Span
@@ -64,8 +68,7 @@ trait Span extends BaseSpan {
 
   def annotate(timestampMicroseconds: Long, name: String, fields: Map[String, String]): Span =
     annotate(Span.Annotation(timestampMicroseconds, name, fields))
-
-
+  
 }
 
 object Span {
@@ -76,6 +79,8 @@ object Span {
 
     override def annotate(annotation: Annotation): Span = this
     override def addSpanTag(key: String, value: String): Span = this
+    override def addSpanTag(key: String, value: Long): Span = this
+    override def addSpanTag(key: String, value: Boolean): Span = this
     override def addMetricTag(key: String, value: String): Span = this
     override def addBaggage(key: String, value: String): Span = this
     override def getBaggage(key: String): Option[String] = None
@@ -96,7 +101,7 @@ object Span {
     * @param startTimestampMicros
     * @param reporterRegistry
     */
-  final class Real(spanContext: SpanContext, initialOperationName: String, initialTags: Map[String, String],
+  final class Real(spanContext: SpanContext, initialOperationName: String, initialTags: Map[String, Span.TagValue],
     startTimestampMicros: Long, reporterRegistry: ReporterRegistryImpl, tracer: Tracer) extends Span {
 
     private var collectMetrics: Boolean = true
@@ -104,7 +109,7 @@ object Span {
     private val sampled: Boolean = spanContext.samplingDecision == SamplingDecision.Sample
     private var operationName: String = initialOperationName
 
-    private var spanTags = initialTags
+    private var spanTags: Map[String, Span.TagValue] = initialTags
     private var customMetricTags = Map.empty[String, String]
     private var annotations = List.empty[Span.Annotation]
 
@@ -116,7 +121,21 @@ object Span {
 
     override def addSpanTag(key: String, value: String): Span = synchronized {
       if(sampled && open)
-        spanTags = spanTags + (key -> value)
+        spanTags = spanTags + (key -> TagValue.String(value))
+      this
+    }
+
+    override def addSpanTag(key: String, value: Long): Span = synchronized {
+      if(sampled && open)
+        spanTags = spanTags + (key -> TagValue.Number(value))
+      this
+    }
+
+    override def addSpanTag(key: String, value: Boolean): Span = synchronized {
+      if(sampled && open) {
+        val tagValue = if (value) TagValue.True else TagValue.False
+        spanTags = spanTags + (key -> tagValue)
+      }
       this
     }
 
@@ -174,7 +193,7 @@ object Span {
       latencyHistogram.record(elapsedTime)
 
       spanTags.get("error").foreach { errorTag =>
-        if(errorTag != null && errorTag.equals(Span.BooleanTagTrueValue)) {
+        if(errorTag != null && errorTag.equals(TagValue.True)) {
           Span.Metrics.SpanErrorCount.refine(metricTags).increment()
         }
       }
@@ -182,20 +201,26 @@ object Span {
   }
 
   object Real {
-    def apply(spanContext: SpanContext, initialOperationName: String, initialTags: Map[String, String],
+    def apply(spanContext: SpanContext, initialOperationName: String, initialTags: Map[String, Span.TagValue],
         startTimestampMicros: Long, reporterRegistry: ReporterRegistryImpl, tracer: Tracer): Real =
       new Real(spanContext, initialOperationName, initialTags, startTimestampMicros, reporterRegistry, tracer)
   }
 
+  sealed trait TagValue
+  object TagValue {
+    sealed trait Boolean extends TagValue
+    case object True extends Boolean
+    case object False extends Boolean
+
+    case class String(string: java.lang.String) extends TagValue
+    case class Number(number: Long) extends TagValue
+  }
 
   object Metrics {
     val SpanProcessingTimeMetric = Kamon.histogram("span.processing-time", MeasurementUnit.time.microseconds)
     val SpanErrorCount = Kamon.counter("span.error-count")
   }
 
-  val BooleanTagTrueValue = "1"
-  val BooleanTagFalseValue = "0"
-
   case class Annotation(timestampMicros: Long, name: String, fields: Map[String, String])
 
   case class FinishedSpan(
@@ -203,7 +228,7 @@ object Span {
     operationName: String,
     startTimestampMicros: Long,
     endTimestampMicros: Long,
-    tags: Map[String, String],
+    tags: Map[String, Span.TagValue],
     annotations: Seq[Annotation]
   )
 }
\ No newline at end of file
diff --git a/kamon-core/src/main/scala/kamon/trace/Tracer.scala b/kamon-core/src/main/scala/kamon/trace/Tracer.scala
index c10974f5..d7ca5609 100644
--- a/kamon-core/src/main/scala/kamon/trace/Tracer.scala
+++ b/kamon-core/src/main/scala/kamon/trace/Tracer.scala
@@ -21,6 +21,7 @@ import java.nio.ByteBuffer
 import com.typesafe.config.Config
 import kamon.ReporterRegistryImpl
 import kamon.metric.MetricLookup
+import kamon.trace.Span.TagValue
 import kamon.trace.SpanContext.{SamplingDecision, Source}
 import kamon.trace.Tracer.SpanBuilder
 import kamon.util.Clock
@@ -114,7 +115,7 @@ object Tracer {
   final class SpanBuilder(operationName: String, tracer: Tracer.Default, reporterRegistry: ReporterRegistryImpl) {
     private var parentContext: SpanContext = _
     private var startTimestamp = 0L
-    private var initialTags = Map.empty[String, String]
+    private var initialTags = Map.empty[String, Span.TagValue]
     private var useActiveSpanAsParent = true
 
     def asChildOf(parentContext: SpanContext): SpanBuilder = {
@@ -126,7 +127,18 @@ object Tracer {
       asChildOf(parentSpan.context())
 
     def withSpanTag(key: String, value: String): SpanBuilder = {
-      this.initialTags = this.initialTags + (key -> value)
+      this.initialTags = this.initialTags + (key -> TagValue.String(value))
+      this
+    }
+
+    def withSpanTag(key: String, value: Long): SpanBuilder = {
+      this.initialTags = this.initialTags + (key -> TagValue.Number(value))
+      this
+    }
+
+    def withSpanTag(key: String, value: Boolean): SpanBuilder = {
+      val tagValue = if (value) TagValue.True else TagValue.False
+      this.initialTags = this.initialTags + (key -> tagValue)
       this
     }