1 files changed, 125 insertions, 0 deletions
diff --git a/src/go/collectors/go.d.plugin/pkg/metrics/summary.go b/src/go/collectors/go.d.plugin/pkg/metrics/summary.go
new file mode 100644
index 000000000..01b85f65e
--- /dev/null
+++ b/src/go/collectors/go.d.plugin/pkg/metrics/summary.go
@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package metrics
+
+import (
+	"math"
+
+	"github.com/netdata/netdata/go/go.d.plugin/pkg/stm"
+)
+
+type (
+	// A Summary captures individual observations from an event or sample stream and
+	// summarizes them in a manner similar to traditional summary statistics:
+	//   sum of observations
+	//   observation count
+	//   observation average.
+	//
+	// To create summary instances, use NewSummary.
+	Summary interface {
+		Observer
+		Reset()
+	}
+
+	// SummaryVec is a Collector that bundles a set of Summary which have different values for their names.
+	// This is used if you want to count the same thing partitioned by various dimensions
+	// (e.g. number of HTTP response time, partitioned by response code and method).
+	//
+	// Create instances with NewSummaryVec.
+	SummaryVec map[string]Summary
+
+	summary struct {
+		min   float64
+		max   float64
+		sum   float64
+		count int64
+	}
+)
+
+var (
+	_ stm.Value = summary{}
+	_ stm.Value = SummaryVec{}
+)
+
+// NewSummary creates a new Summary.
+func NewSummary() Summary {
+	return &summary{
+		min: math.MaxFloat64,
+		max: -math.MaxFloat64,
+	}
+}
+
+// WriteTo writes its values into given map.
+// It adds those key-value pairs:
+//
+//	${key}_sum        gauge, for sum of it's observed values from last Reset calls
+//	${key}_count      counter, for count of it's observed values from last Reset calls
+//	${key}_min        gauge, for min of it's observed values from last Reset calls (only exists if count > 0)
+//	${key}_max        gauge, for max of it's observed values from last Reset calls (only exists if count > 0)
+//	${key}_avg        gauge, for avg of it's observed values from last Reset calls (only exists if count > 0)
+func (s summary) WriteTo(rv map[string]int64, key string, mul, div int) {
+	if s.count > 0 {
+		rv[key+"_min"] = int64(s.min * float64(mul) / float64(div))
+		rv[key+"_max"] = int64(s.max * float64(mul) / float64(div))
+		rv[key+"_sum"] = int64(s.sum * float64(mul) / float64(div))
+		rv[key+"_count"] = s.count
+		rv[key+"_avg"] = int64(s.sum / float64(s.count) * float64(mul) / float64(div))
+	} else {
+		rv[key+"_count"] = 0
+		rv[key+"_sum"] = 0
+		delete(rv, key+"_min")
+		delete(rv, key+"_max")
+		delete(rv, key+"_avg")
+	}
+}
+
+// Reset resets all of its counters.
+// Call it before every scrape loop.
+func (s *summary) Reset() {
+	s.min = math.MaxFloat64
+	s.max = -math.MaxFloat64
+	s.sum = 0
+	s.count = 0
+}
+
+// Observe observes a value
+func (s *summary) Observe(v float64) {
+	if v > s.max {
+		s.max = v
+	}
+	if v < s.min {
+		s.min = v
+	}
+	s.sum += v
+	s.count++
+}
+
+// NewSummaryVec creates a new SummaryVec instance.
+func NewSummaryVec() SummaryVec {
+	return SummaryVec{}
+}
+
+// WriteTo writes its value into given map.
+func (c SummaryVec) WriteTo(rv map[string]int64, key string, mul, div int) {
+	for name, value := range c {
+		value.WriteTo(rv, key+"_"+name, mul, div)
+	}
+}
+
+// Get gets counter instance by name.
+func (c SummaryVec) Get(name string) Summary {
+	item, ok := c[name]
+	if ok {
+		return item
+	}
+	item = NewSummary()
+	c[name] = item
+	return item
+}
+
+// Reset resets its all summaries.
+func (c SummaryVec) Reset() {
+	for _, value := range c {
+		value.Reset()
+	}
+}