From 1362c6d002e6c65da1d78da3e1c3cf8b4a180636 Mon Sep 17 00:00:00 2001
From: Kamil Samigullin <kamil@samigullin.info>
Date: Mon, 24 Jun 2019 16:43:16 +0300
Subject: [PATCH] add bench to test overhead

---
 Makefile       |  2 +-
 README.md      | 14 ++++++++++++++
 tracer.go      | 10 ++++------
 tracer_test.go | 13 ++++++++++---
 4 files changed, 29 insertions(+), 10 deletions(-)

diff --git a/Makefile b/Makefile
index 63af7f4..fbcda2b 100644
--- a/Makefile
+++ b/Makefile
@@ -5,7 +5,7 @@ GOFLAGS     = -mod=vendor
 TIMEOUT     = 1s
 
 
-.DEFAULT_GOAL = test
+.DEFAULT_GOAL = test-with-coverage
 
 
 .PHONY: deps
diff --git a/README.md b/README.md
index 8dbf01c..1c1bc5e 100644
--- a/README.md
+++ b/README.md
@@ -4,6 +4,7 @@
 
 [![Build][icon_build]][page_build]
 [![Coverage][icon_coverage]][page_coverage]
+[![Quality][icon_quality]][page_quality]
 [![Documentation][icon_docs]][page_docs]
 
 ## 💡 Idea
@@ -82,6 +83,17 @@ func StoreIntoDatabase(ctx context.Context, data Data) error {
 }
 ```
 
+Output:
+
+```
+allocates at call stack: 1, detailed call stack:
+	call tracer_test.Handle [ca7a87c4-58d0-4fdf-857c-ef49fc3bf271]: 14.038083ms, allocates: 2
+		checkpoint [serialize]: 1.163587ms
+		checkpoint [store]: 2.436265ms
+	call tracer_test.FetchData: 1.192829ms, allocates: 0
+	call tracer_test.StoreIntoDatabase: 10.428663ms, allocates: 0
+```
+
 ## 🧩 Integration
 
 This library uses [SemVer](https://semver.org/) for versioning, and it is not
@@ -101,11 +113,13 @@ made with ❤️ for everyone
 [icon_build]:      https://travis-ci.org/kamilsk/tracer.svg?branch=master
 [icon_coverage]:   https://api.codeclimate.com/v1/badges/fb66449d1f5c64542377/test_coverage
 [icon_docs]:       https://godoc.org/github.com/kamilsk/tracer?status.svg
+[icon_quality]:    https://goreportcard.com/badge/github.com/kamilsk/tracer
 
 [page_build]:      https://travis-ci.org/kamilsk/tracer
 [page_coverage]:   https://codeclimate.com/github/kamilsk/tracer/test_coverage
 [page_docs]:       https://godoc.org/github.com/kamilsk/tracer
 [page_promo]:      https://github.com/kamilsk/tracer
+[page_quality]:    https://goreportcard.com/report/github.com/kamilsk/tracer
 
 [dep]:             https://golang.github.io/dep/
 [gomod]:           https://github.com/golang/go/wiki/Modules
diff --git a/tracer.go b/tracer.go
index fb6aafd..da417fa 100644
--- a/tracer.go
+++ b/tracer.go
@@ -76,26 +76,24 @@ type Call struct {
 	labels      []string
 	caller      CallerInfo
 	start, stop time.Time
-	checkpoints []*Checkpoint
+	checkpoints []Checkpoint
 	allocates   int
 }
 
-func (call *Call) Checkpoint(labels ...string) *Checkpoint {
+func (call *Call) Checkpoint(labels ...string) {
 	if call == nil {
-		return nil
+		return
 	}
 
 	var id string
 	if len(labels) > 0 {
 		id, labels = labels[0], labels[1:]
 	}
-	checkpoint := &Checkpoint{id: id, labels: labels, timestamp: time.Now()}
+	checkpoint := Checkpoint{id: id, labels: labels, timestamp: time.Now()}
 	if len(call.checkpoints) == cap(call.checkpoints) {
 		call.allocates++
 	}
 	call.checkpoints = append(call.checkpoints, checkpoint)
-
-	return checkpoint
 }
 
 func (call *Call) Stop() {
diff --git a/tracer_test.go b/tracer_test.go
index ca03f24..5acfd1e 100644
--- a/tracer_test.go
+++ b/tracer_test.go
@@ -45,16 +45,23 @@ func TestCall_Stop(t *testing.T) {
 	(&Call{}).Stop()
 }
 
-// BenchmarkTracing/silent-12         	  200000	      7755 ns/op	    1816 B/op	      24 allocs/op
-// BenchmarkTracing/full-12           	  200000	      8880 ns/op	    3944 B/op	      45 allocs/op
+// BenchmarkTracing/overhead-12         	 2000000	       616 ns/op	     144 B/op	       9 allocs/op
+// BenchmarkTracing/silent-12           	  200000	      7478 ns/op	    2320 B/op	      27 allocs/op
+// BenchmarkTracing/active-12           	  200000	      9221 ns/op	    4448 B/op	      48 allocs/op
 func BenchmarkTracing(b *testing.B) {
+	b.Run("overhead", func(b *testing.B) {
+		b.ReportAllocs()
+		for i := 0; i < b.N; i++ {
+			traceRoot(context.Background())
+		}
+	})
 	b.Run("silent", func(b *testing.B) {
 		b.ReportAllocs()
 		for i := 0; i < b.N; i++ {
 			traceRoot(Inject(context.Background(), make([]*Call, 0, 9)))
 		}
 	})
-	b.Run("full", func(b *testing.B) {
+	b.Run("active", func(b *testing.B) {
 		b.ReportAllocs()
 		for i := 0; i < b.N; i++ {
 			ctx := Inject(context.Background(), make([]*Call, 0, 9))