Merge pull request #169 from ExpediaDotCom/merge-spantree-fix

fix the bug where span forest should have only one tree after the mer…

Author: Kapil Rastogi

reader/src/main/scala/com/expedia/www/haystack/trace/reader/readers/transformers/ClockSkewTransformer.scala

@@ -30,6 +30,8 @@ import com.expedia.www.haystack.trace.reader.readers.utils.{MutableSpanForest, S
 class ClockSkewTransformer extends SpanTreeTransformer {
 
   override def transform(forest: MutableSpanForest): MutableSpanForest = {
+    require(forest.getAllTrees.size == 1)
+    
     val clockedSkewAdjusted = adjustSkew(forest.getAllTrees.head, None)
     forest.updateUnderlyingSpans(clockedSkewAdjusted)
   }

reader/src/main/scala/com/expedia/www/haystack/trace/reader/readers/utils/SpanTree.scala

@@ -66,6 +66,8 @@ case class MutableSpanForest(private var spans: Seq[Span]) {
     })
 
     updateUnderlyingSpanWith(toBeUpdatedUnderlyingSpans)
+    this.forest = mutable.ListBuffer[SpanTree](root)
+    needForestUpdate = false
     this
   }
 

reader/src/test/scala/com/expedia/www/haystack/trace/reader/unit/readers/transformers/InvalidParentTransformerSpec.scala

@@ -41,7 +41,8 @@ class InvalidParentTransformerSpec extends BaseUnitTestSpec {
       )
 
       When("invoking transform")
-      val transformedSpans = new InvalidParentTransformer().transform(MutableSpanForest(spans)).getUnderlyingSpans
+      val transformedSpanTree = new InvalidParentTransformer().transform(MutableSpanForest(spans))
+      val transformedSpans = transformedSpanTree.getUnderlyingSpans
 
       Then("mark root to be parent of spans with invalid parent id")
       transformedSpans.length should be(3)
@@ -54,6 +55,8 @@ class InvalidParentTransformerSpec extends BaseUnitTestSpec {
 
       val cSpan = transformedSpans.find(_.getSpanId == "c")
       cSpan.get.getParentSpanId should be("a")
+
+      transformedSpanTree.getAllTrees.size shouldBe 1
     }
 
     it("should mark root as parent for spans with parent ids that are not in the trace") {