Merge pull request #65 from getamis/counter-vec

metrics: support counter vec

metrics/dummy.go

@@ -58,6 +58,10 @@ func (d *DummyRegistry) NewHistogramVec(key string, labels []string, opts ...Opt
 	return &dummyHistogramVec{}
 }
 
+func (d *DummyRegistry) NewCounterVec(key string, labels []string, opts ...Option) CounterVec {
+	return &dummyCounterVec{}
+}
+
 func (d *DummyRegistry) NewTimer(key string, opts ...Option) Timer {
 	return &dummyTimer{}
 }
@@ -95,17 +99,20 @@ func (d *dummyHistogram) Observe(float64) {}
 
 type dummyHistogramVec struct{}
 
-func (d *dummyHistogramVec) GetMetricWith(HistogramLabels) (HistogramObserver, error) {
+func (d *dummyHistogramVec) GetMetricWith(MetricsLabels) (Histogram, error) {
 	return &dummyHistogram{}, nil
 }
-func (d *dummyHistogramVec) GetMetricWithLabelValues(lvs ...string) (HistogramObserver, error) {
+func (d *dummyHistogramVec) GetMetricWithLabelValues(lvs ...string) (Histogram, error) {
 	return &dummyHistogram{}, nil
 }
-func (d *dummyHistogramVec) With(HistogramLabels) HistogramObserver {
-	return &dummyHistogram{}
+
+type dummyCounterVec struct{}
+
+func (d *dummyCounterVec) GetMetricWith(MetricsLabels) (Counter, error) {
+	return &dummyCounter{}, nil
 }
-func (d *dummyHistogramVec) WithLabelValues(...string) HistogramObserver {
-	return &dummyHistogram{}
+func (d *dummyCounterVec) GetMetricWithLabelValues(lvs ...string) (Counter, error) {
+	return &dummyCounter{}, nil
 }
 
 type dummyTimer struct{}

metrics/metrics.go

@@ -32,6 +32,14 @@ type Counter interface {
 	Add(float64)
 }
 
+type MetricsLabels = prom.Labels
+
+// CounterVec is returned by NewCounterVec.
+type CounterVec interface {
+	GetMetricWith(MetricsLabels) (Counter, error)
+	GetMetricWithLabelValues(lvs ...string) (Counter, error)
+}
+
 // Gauge is a Metric that represents a single numerical value that can
 // arbitrarily go up and down.
 // A Gauge is typically used for measured values like temperatures or current
@@ -47,13 +55,10 @@ type Histogram interface {
 	Observe(float64)
 }
 
-type HistogramLabels = prom.Labels
-type HistogramObserver = prom.Observer
-
 // HistogramVec is returned by NewHistogramVec.
 type HistogramVec interface {
-	GetMetricWith(HistogramLabels) (HistogramObserver, error)
-	GetMetricWithLabelValues(lvs ...string) (HistogramObserver, error)
+	GetMetricWith(MetricsLabels) (Histogram, error)
+	GetMetricWithLabelValues(lvs ...string) (Histogram, error)
 }
 
 // Timer represents a Histogram Metrics to observe the time duration according to given begin time.

metrics/prometheus.go

@@ -184,11 +184,11 @@ func (p *PrometheusRegistry) NewHistogramVec(key string, labels []string, opts .
 	if err != nil {
 		reg, ok := err.(prom.AlreadyRegisteredError)
 		if ok {
-			return reg.ExistingCollector.(*prom.HistogramVec)
+			return &histogramVec{reg.ExistingCollector.(*prom.HistogramVec)}
 		}
 		log.Warn("Failed to register a histogram vector", "key", key, "err", err)
 	}
-	return hv
+	return &histogramVec{hv}
 }
 
 func (p *PrometheusRegistry) NewTimer(key string, opts ...Option) Timer {
@@ -198,7 +198,7 @@ func (p *PrometheusRegistry) NewTimer(key string, opts ...Option) Timer {
 }
 
 func (p *PrometheusRegistry) NewWorker(key string, opts ...Option) Worker {
-	counterVec := p.newCounterVec(key, []string{"result"}, opts...)
+	counterVec := p.NewCounterVec(key, []string{"result"}, opts...)
 	// These are just references (no increments),
 	// as just referencing will create the labels but not set values.
 	success, _ := counterVec.GetMetricWithLabelValues("success")
@@ -210,7 +210,7 @@ func (p *PrometheusRegistry) NewWorker(key string, opts ...Option) Worker {
 	}
 }
 
-func (p *PrometheusRegistry) newCounterVec(key string, labelNames []string, opts ...Option) *prom.CounterVec {
+func (p *PrometheusRegistry) NewCounterVec(key string, labelNames []string, opts ...Option) CounterVec {
 	options := NewOptions(p.namespace, "", p.labels)
 	for _, fn := range opts {
 		fn(options)
@@ -226,12 +226,12 @@ func (p *PrometheusRegistry) newCounterVec(key string, labelNames []string, opts
 	if err != nil {
 		reg, ok := err.(prom.AlreadyRegisteredError)
 		if ok {
-			return reg.ExistingCollector.(*prom.CounterVec)
+			existingCV := reg.ExistingCollector.(*prom.CounterVec)
+			return &counterVec{existingCV}
 		}
 		log.Warn("Failed to register a counter vec", "key", key, "err", err)
 	}
-	return cnt
-
+	return &counterVec{cnt}
 }
 
 // -----------------------------------------------------------------------------
@@ -260,3 +260,29 @@ func (w *worker) Observe(begin time.Time, err error) {
 	}
 	w.success.Inc()
 }
+
+// -----------------------------------------------------------------------------
+// counterVec
+type counterVec struct {
+	*prom.CounterVec
+}
+
+func (c *counterVec) GetMetricWith(labels MetricsLabels) (Counter, error) {
+	return c.CounterVec.GetMetricWith(labels)
+}
+func (c *counterVec) GetMetricWithLabelValues(lvs ...string) (Counter, error) {
+	return c.CounterVec.GetMetricWithLabelValues(lvs...)
+}
+
+// -----------------------------------------------------------------------------
+// histogramVec
+type histogramVec struct {
+	*prom.HistogramVec
+}
+
+func (h *histogramVec) GetMetricWith(labels MetricsLabels) (Histogram, error) {
+	return h.HistogramVec.GetMetricWith(labels)
+}
+func (h *histogramVec) GetMetricWithLabelValues(lvs ...string) (Histogram, error) {
+	return h.HistogramVec.GetMetricWithLabelValues(lvs...)
+}

metrics/registery.go

@@ -46,6 +46,7 @@ type Registry interface {
 	NewGauge(key string, opts ...Option) Gauge
 	NewHistogram(key string, opts ...Option) Histogram
 	NewHistogramVec(key string, labels []string, opts ...Option) HistogramVec
+	NewCounterVec(key string, labels []string, opts ...Option) CounterVec
 	NewTimer(key string, opts ...Option) Timer
 	NewWorker(key string, opts ...Option) Worker
 
@@ -77,6 +78,10 @@ func NewHistogramVec(key string, labels []string, opts ...Option) HistogramVec {
 	return DefaultRegistry.NewHistogramVec(key, labels, opts...)
 }
 
+func NewCounterVec(key string, labels []string, opts ...Option) CounterVec {
+	return DefaultRegistry.NewCounterVec(key, labels, opts...)
+}
+
 func NewTimer(key string, opts ...Option) Timer {
 	return DefaultRegistry.NewTimer(key, opts...)
 }