Implement base stats snapshot

stats/base.go

@@ -23,30 +23,28 @@ type Stats interface {
 	Processed() int64
 	Errors() int64
 	Min() int64
-	Max() int64
-	P95() float64
 	Mean() float64
+	P95() float64
+	Max() int64
 	StdDev() float64
 }
 
-type base struct {
-	sync.Mutex
-	stats      map[string]*baseStats
-	sampleSize int
-}
-
-type baseStats struct {
-	name   string
-	time   metrics.Histogram
-	errors metrics.Counter
-}
-
 const (
 	DefaultSampleSize = 1000
 	Latency           = "Latency"
 	TaskWait          = "TaskWait"
 )
 
+//
+// base
+//
+
+type base struct {
+	sync.Mutex
+	stats      map[string]*baseStats
+	sampleSize int
+}
+
 func (b *base) Add(name string, dur time.Duration) {
 	b.metrics(name).time.Update(int64(dur))
 }
@@ -66,54 +64,6 @@ func (b *base) Reset() {
 	}
 }
 
-func (s *baseStats) Processed() int64 {
-	return s.time.Count()
-}
-
-func (s *baseStats) Errors() int64 {
-	return s.errors.Count()
-}
-
-func (s *baseStats) Min() int64 {
-	return s.time.Min()
-}
-
-func (s *baseStats) Max() int64 {
-	return s.time.Max()
-}
-
-func (s *baseStats) P95() float64 {
-	return s.time.Percentile(0.95)
-}
-
-func (s *baseStats) Mean() float64 {
-	return s.time.Mean()
-}
-
-func (s *baseStats) StdDev() float64 {
-	return s.time.StdDev()
-}
-
-func (s *baseStats) String() string {
-	return fmt.Sprintf("%s statistics:\n"+
-		"Processed: %10d\n"+
-		"Errors:    %10d\n"+
-		"Min:       %10s\n"+
-		"Mean:      %10s\n"+
-		"95%%:       %10s\n"+
-		"Max:       %10s\n"+
-		"StdDev:    %10s",
-		s.name,
-		s.time.Count(),
-		s.errors.Count(),
-		formatDuration(float64(s.time.Min())),
-		formatDuration(s.time.Mean()),
-		formatDuration(s.time.Percentile(0.95)),
-		formatDuration(float64(s.time.Max())),
-		formatDuration(s.time.StdDev()),
-	)
-}
-
 func (b *base) init() {
 	b.stats = make(map[string]*baseStats)
 }
@@ -141,6 +91,122 @@ func (b *base) metrics(name string) *baseStats {
 	return b.stats[name]
 }
 
+//
+// baseStats
+//
+
+type baseStats struct {
+	name   string
+	time   metrics.Histogram
+	errors metrics.Counter
+}
+
+func (s *baseStats) Processed() int64 {
+	return s.time.Count()
+}
+
+func (s *baseStats) Errors() int64 {
+	return s.errors.Count()
+}
+
+func (s *baseStats) Min() int64 {
+	return s.time.Min()
+}
+
+func (s *baseStats) Mean() float64 {
+	return s.time.Mean()
+}
+
+func (s *baseStats) P95() float64 {
+	return s.time.Percentile(0.95)
+}
+
+func (s *baseStats) Max() int64 {
+	return s.time.Max()
+}
+
+func (s *baseStats) StdDev() float64 {
+	return s.time.StdDev()
+}
+
+func (s *baseStats) String() string {
+	return fmt.Sprintf("%s statistics:\n"+
+		"Processed: %10d\n"+
+		"Errors:    %10d\n"+
+		"Min:       %10s\n"+
+		"Mean:      %10s\n"+
+		"95%%:       %10s\n"+
+		"Max:       %10s\n"+
+		"StdDev:    %10s",
+		s.name,
+		s.time.Count(),
+		s.errors.Count(),
+		formatDuration(float64(s.time.Min())),
+		formatDuration(s.time.Mean()),
+		formatDuration(s.time.Percentile(0.95)),
+		formatDuration(float64(s.time.Max())),
+		formatDuration(s.time.StdDev()),
+	)
+}
+
+func (s *baseStats) snapshot() *baseSnapshot {
+	return &baseSnapshot{
+		ProcessedVal: s.time.Count(),
+		ErrorsVal:    s.errors.Count(),
+		MinVal:       s.time.Min(),
+		MeanVal:      s.time.Mean(),
+		P95Val:       s.time.Percentile(0.95),
+		MaxVal:       s.time.Max(),
+		StdDevVal:    s.time.StdDev(),
+	}
+}
+
+//
+// baseSnapshot
+//
+
+type baseSnapshot struct {
+	ProcessedVal int64   `json:"processed"`
+	ErrorsVal    int64   `json:"errors"`
+	MinVal       int64   `json:"min"`
+	MeanVal      float64 `json:"mean"`
+	P95Val       float64 `json:"95%"`
+	MaxVal       int64   `json:"max"`
+	StdDevVal    float64 `json:"stddev"`
+}
+
+func (s *baseSnapshot) Processed() int64 {
+	return s.ProcessedVal
+}
+
+func (s *baseSnapshot) Errors() int64 {
+	return s.ErrorsVal
+}
+
+func (s *baseSnapshot) Min() int64 {
+	return s.MinVal
+}
+
+func (s *baseSnapshot) Mean() float64 {
+	return s.MeanVal
+}
+
+func (s *baseSnapshot) P95() float64 {
+	return s.P95Val
+}
+
+func (s *baseSnapshot) Max() int64 {
+	return s.MaxVal
+}
+
+func (s *baseSnapshot) StdDev() float64 {
+	return s.StdDevVal
+}
+
+//
+// Helpers
+//
+
 func formatDuration(dur float64) string {
 	switch {
 	case dur < 1000: