From 880d8e1cc60b0a3b564b1c41cc3d9b829723e759 Mon Sep 17 00:00:00 2001
From: greyireland <fruitbag@163.com>
Date: Mon, 20 Feb 2023 12:54:52 +0800
Subject: [PATCH] backward compatibility

---
 histogram.go |  8 ++++----
 push.go      |  4 ++--
 set.go       | 41 +++++++++++++++++++++++++++++++++++++----
 set_test.go  |  4 ++--
 4 files changed, 45 insertions(+), 12 deletions(-)

diff --git a/histogram.go b/histogram.go
index bd023d8..47af50c 100644
--- a/histogram.go
+++ b/histogram.go
@@ -152,10 +152,10 @@ func (h *Histogram) VisitNonZeroBuckets(f func(vmrange string, count uint64)) {
 //
 // The returned histogram is safe to use from concurrent goroutines.
 func NewHistogram(name string) *Histogram {
-	return defaultSet.NewHistogram(name, false)
+	return defaultSet.NewHistogram(name)
 }
 func NewCompatibleHistogram(name string) *Histogram {
-	return defaultSet.NewHistogram(name, true)
+	return defaultSet.NewCompatibleHistogram(name)
 }
 
 // GetOrCreateHistogram returns registered histogram with the given name
@@ -173,10 +173,10 @@ func NewCompatibleHistogram(name string) *Histogram {
 //
 // Performance tip: prefer NewHistogram instead of GetOrCreateHistogram.
 func GetOrCreateHistogram(name string) *Histogram {
-	return defaultSet.GetOrCreateHistogram(name, false)
+	return defaultSet.GetOrCreateHistogram(name)
 }
 func GetOrCreateCompatibleHistogram(name string) *Histogram {
-	return defaultSet.GetOrCreateHistogram(name, true)
+	return defaultSet.GetOrCreateCompatibleHistogram(name)
 }
 
 // UpdateDuration updates request duration based on the given startTime.
diff --git a/push.go b/push.go
index f878408..4215f48 100644
--- a/push.go
+++ b/push.go
@@ -115,8 +115,8 @@ func InitPushExt(pushURL string, interval time.Duration, extraLabels string, wri
 	pushesTotal := pushMetrics.GetOrCreateCounter(fmt.Sprintf(`metrics_push_total{url=%q}`, pushURLRedacted))
 	pushErrorsTotal := pushMetrics.GetOrCreateCounter(fmt.Sprintf(`metrics_push_errors_total{url=%q}`, pushURLRedacted))
 	bytesPushedTotal := pushMetrics.GetOrCreateCounter(fmt.Sprintf(`metrics_push_bytes_pushed_total{url=%q}`, pushURLRedacted))
-	pushDuration := pushMetrics.GetOrCreateHistogram(fmt.Sprintf(`metrics_push_duration_seconds{url=%q}`, pushURLRedacted), false)
-	pushBlockSize := pushMetrics.GetOrCreateHistogram(fmt.Sprintf(`metrics_push_block_size_bytes{url=%q}`, pushURLRedacted), false)
+	pushDuration := pushMetrics.GetOrCreateHistogram(fmt.Sprintf(`metrics_push_duration_seconds{url=%q}`, pushURLRedacted))
+	pushBlockSize := pushMetrics.GetOrCreateHistogram(fmt.Sprintf(`metrics_push_block_size_bytes{url=%q}`, pushURLRedacted))
 	pushMetrics.GetOrCreateFloatCounter(fmt.Sprintf(`metrics_push_interval_seconds{url=%q}`, pushURLRedacted)).Set(interval.Seconds())
 	go func() {
 		ticker := time.NewTicker(interval)
diff --git a/set.go b/set.go
index 6ecbfe2..d7bc371 100644
--- a/set.go
+++ b/set.go
@@ -65,8 +65,13 @@ func (s *Set) WritePrometheus(w io.Writer) {
 //   - foo{bar="baz",aaa="b"}
 //
 // The returned histogram is safe to use from concurrent goroutines.
-func (s *Set) NewHistogram(name string, compatible bool) *Histogram {
-	h := &Histogram{compatible: compatible}
+func (s *Set) NewHistogram(name string) *Histogram {
+	h := &Histogram{}
+	s.registerMetric(name, h)
+	return h
+}
+func (s *Set) NewCompatibleHistogram(name string) *Histogram {
+	h := &Histogram{compatible: true}
 	s.registerMetric(name, h)
 	return h
 }
@@ -84,7 +89,7 @@ func (s *Set) NewHistogram(name string, compatible bool) *Histogram {
 // The returned histogram is safe to use from concurrent goroutines.
 //
 // Performance tip: prefer NewHistogram instead of GetOrCreateHistogram.
-func (s *Set) GetOrCreateHistogram(name string, compatible bool) *Histogram {
+func (s *Set) GetOrCreateHistogram(name string) *Histogram {
 	s.mu.Lock()
 	nm := s.m[name]
 	s.mu.Unlock()
@@ -95,7 +100,35 @@ func (s *Set) GetOrCreateHistogram(name string, compatible bool) *Histogram {
 		}
 		nmNew := &namedMetric{
 			name:   name,
-			metric: &Histogram{compatible: compatible},
+			metric: &Histogram{},
+		}
+		s.mu.Lock()
+		nm = s.m[name]
+		if nm == nil {
+			nm = nmNew
+			s.m[name] = nm
+			s.a = append(s.a, nm)
+		}
+		s.mu.Unlock()
+	}
+	h, ok := nm.metric.(*Histogram)
+	if !ok {
+		panic(fmt.Errorf("BUG: metric %q isn't a Histogram. It is %T", name, nm.metric))
+	}
+	return h
+}
+func (s *Set) GetOrCreateCompatibleHistogram(name string) *Histogram {
+	s.mu.Lock()
+	nm := s.m[name]
+	s.mu.Unlock()
+	if nm == nil {
+		// Slow path - create and register missing histogram.
+		if err := validateMetric(name); err != nil {
+			panic(fmt.Errorf("BUG: invalid metric name %q: %s", name, err))
+		}
+		nmNew := &namedMetric{
+			name:   name,
+			metric: &Histogram{compatible: true},
 		}
 		s.mu.Lock()
 		nm = s.m[name]
diff --git a/set_test.go b/set_test.go
index 4ddba29..66ed07a 100644
--- a/set_test.go
+++ b/set_test.go
@@ -29,7 +29,7 @@ func TestNewSet(t *testing.T) {
 			if sm == nil {
 				t.Fatalf("NewSummary returned nil")
 			}
-			h := s.NewHistogram(fmt.Sprintf("histogram_%d", j), false)
+			h := s.NewHistogram(fmt.Sprintf("histogram_%d", j))
 			if h == nil {
 				t.Fatalf("NewHistogram returned nil")
 			}
@@ -71,7 +71,7 @@ func TestSetUnregisterAllMetrics(t *testing.T) {
 		for i := 0; i < 10; i++ {
 			_ = s.NewCounter(fmt.Sprintf("counter_%d", i))
 			_ = s.NewSummary(fmt.Sprintf("summary_%d", i))
-			_ = s.NewHistogram(fmt.Sprintf("histogram_%d", i), false)
+			_ = s.NewHistogram(fmt.Sprintf("histogram_%d", i))
 			_ = s.NewGauge(fmt.Sprintf("gauge_%d", i), func() float64 { return 0 })
 			expectedMetricsCount += 4
 		}