fix(flamegraph): More accurate average computation for flamegraph metrics

Take 2 of #635. This aims to consolidate all the metrics into the frame into
list and deprecates the metrics list.

Author: Zylphrex

internal/chunk/sample_test.go

@@ -40,6 +40,7 @@ func TestCallTrees(t *testing.T) {
 				"1": {
 					{
 						DurationNS:    40_000_000,
+						DurationsNS:   []uint64{40_000_000},
 						EndNS:         50_000_000,
 						Fingerprint:   15444731332182868858,
 						IsApplication: true,
@@ -52,6 +53,7 @@ func TestCallTrees(t *testing.T) {
 						Children: []*nodetree.Node{
 							{
 								DurationNS:    40_000_000,
+								DurationsNS:   []uint64{40_000_000},
 								EndNS:         50_000_000,
 								StartNS:       10_000_000,
 								Fingerprint:   14164357600995800812,
@@ -64,6 +66,7 @@ func TestCallTrees(t *testing.T) {
 								Children: []*nodetree.Node{
 									{
 										DurationNS:    10_000_000,
+										DurationsNS:   []uint64{10_000_000},
 										EndNS:         50_000_000,
 										Fingerprint:   9531802423075301657,
 										IsApplication: true,
@@ -104,6 +107,7 @@ func TestCallTrees(t *testing.T) {
 				"1": {
 					{
 						DurationNS:    30_000_000,
+						DurationsNS:   []uint64{30_000_000},
 						EndNS:         40_000_000,
 						Fingerprint:   15444731332182868858,
 						IsApplication: true,
@@ -116,6 +120,7 @@ func TestCallTrees(t *testing.T) {
 						Children: []*nodetree.Node{
 							{
 								DurationNS:    30_000_000,
+								DurationsNS:   []uint64{30_000_000},
 								EndNS:         40_000_000,
 								Fingerprint:   14164357600995800812,
 								IsApplication: true,
@@ -156,6 +161,7 @@ func TestCallTrees(t *testing.T) {
 				"1": {
 					{
 						DurationNS:    10_000_000,
+						DurationsNS:   []uint64{10_000_000},
 						EndNS:         20_000_000,
 						Fingerprint:   15444731332182868858,
 						IsApplication: true,
@@ -168,6 +174,7 @@ func TestCallTrees(t *testing.T) {
 					},
 					{
 						DurationNS:    10_000_000,
+						DurationsNS:   []uint64{10_000_000},
 						EndNS:         30_000_000,
 						Fingerprint:   15444731332182868859,
 						IsApplication: true,

internal/flamegraph/flamegraph.go

@@ -63,6 +63,8 @@ func addCallTreeToFlamegraph(flamegraphTree *[]*nodetree.Node, callTree []*nodet
 			currentNode.Occurrence += node.Occurrence
 			currentNode.SampleCount += node.SampleCount
 			currentNode.DurationNS += node.DurationNS
+			currentNode.SelfTimeNS += node.SelfTimeNS
+			currentNode.DurationsNS = append(currentNode.DurationsNS, node.DurationsNS...)
 		} else {
 			currentNode = node.ShallowCopyWithoutChildren()
 			*flamegraphTree = append(*flamegraphTree, currentNode)
@@ -186,6 +188,16 @@ func toSpeedscope(
 		fd.visitCalltree(tree, &stack)
 	}
 
+	for i, frameInfo := range fd.frameInfos {
+		sort.Slice(frameInfo.DurationsNS, func(i, j int) bool {
+			return frameInfo.DurationsNS[i] < frameInfo.DurationsNS[j]
+		})
+		frameInfo.P75Duration, _ = metrics.Quantile(frameInfo.DurationsNS, 0.75)
+		frameInfo.P95Duration, _ = metrics.Quantile(frameInfo.DurationsNS, 0.95)
+		frameInfo.P99Duration, _ = metrics.Quantile(frameInfo.DurationsNS, 0.99)
+		fd.frameInfos[i] = frameInfo
+	}
+
 	s.SetData("total_samples", fd.totalSamples)
 	s.SetData("final_samples", fd.Len())
 
@@ -228,6 +240,9 @@ func (f *flamegraph) visitCalltree(node *nodetree.Node, currentStack *[]int) {
 		*currentStack = append(*currentStack, i)
 		f.frameInfos[i].Count += node.Occurrence
 		f.frameInfos[i].Weight += node.DurationNS
+		f.frameInfos[i].SumDuration += node.DurationNS
+		f.frameInfos[i].SumSelfTime += node.SelfTimeNS
+		f.frameInfos[i].DurationsNS = append(f.frameInfos[i].DurationsNS, node.DurationsNS...)
 	} else {
 		frame := node.ToFrame()
 		sfr := speedscope.Frame{
@@ -245,8 +260,11 @@ func (f *flamegraph) visitCalltree(node *nodetree.Node, currentStack *[]int) {
 		*currentStack = append(*currentStack, len(f.frames))
 		f.frames = append(f.frames, sfr)
 		f.frameInfos = append(f.frameInfos, speedscope.FrameInfo{
-			Count:  node.Occurrence,
-			Weight: node.DurationNS,
+			Count:       node.Occurrence,
+			Weight:      node.DurationNS,
+			SumDuration: node.DurationNS,
+			SumSelfTime: node.SelfTimeNS,
+			DurationsNS: node.DurationsNS,
 		})
 	}