1 files changed, 93 insertions, 0 deletions
diff --git a/src/go/collectors/go.d.plugin/pkg/metrics/counter.go b/src/go/collectors/go.d.plugin/pkg/metrics/counter.go
new file mode 100644
index 000000000..7231fc7a4
--- /dev/null
+++ b/src/go/collectors/go.d.plugin/pkg/metrics/counter.go
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package metrics
+
+import (
+	"errors"
+
+	"github.com/netdata/netdata/go/go.d.plugin/pkg/stm"
+)
+
+type (
+	// Counter is a Metric that represents a single numerical bits that only ever
+	// goes up. That implies that it cannot be used to count items whose number can
+	// also go down, e.g. the number of currently running goroutines. Those
+	// "counters" are represented by Gauges.
+	//
+	// A Counter is typically used to count requests served, tasks completed, errors
+	// occurred, etc.
+	Counter struct {
+		valInt   int64
+		valFloat float64
+	}
+
+	// CounterVec is a Collector that bundles a set of Counters 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 requests, partitioned by response code and method).
+	//
+	// Create instances with NewCounterVec.
+	CounterVec map[string]*Counter
+)
+
+var (
+	_ stm.Value = Counter{}
+	_ stm.Value = CounterVec{}
+)
+
+// WriteTo writes its value into given map.
+func (c Counter) WriteTo(rv map[string]int64, key string, mul, div int) {
+	rv[key] = int64(c.Value() * float64(mul) / float64(div))
+}
+
+// Value gets current counter.
+func (c Counter) Value() float64 {
+	return float64(c.valInt) + c.valFloat
+}
+
+// Inc increments the counter by 1. Use Add to increment it by arbitrary
+// non-negative values.
+func (c *Counter) Inc() {
+	c.valInt++
+}
+
+// Add adds the given bits to the counter. It panics if the value is < 0.
+func (c *Counter) Add(v float64) {
+	if v < 0 {
+		panic(errors.New("counter cannot decrease in value"))
+	}
+	val := int64(v)
+	if float64(val) == v {
+		c.valInt += val
+		return
+	}
+	c.valFloat += v
+}
+
+// NewCounterVec creates a new CounterVec
+func NewCounterVec() CounterVec {
+	return CounterVec{}
+}
+
+// WriteTo writes its value into given map.
+func (c CounterVec) WriteTo(rv map[string]int64, key string, mul, div int) {
+	for name, value := range c {
+		rv[key+"_"+name] = int64(value.Value() * float64(mul) / float64(div))
+	}
+}
+
+// Get gets counter instance by name
+func (c CounterVec) Get(name string) *Counter {
+	item, _ := c.GetP(name)
+	return item
+}
+
+// GetP gets counter instance by name
+func (c CounterVec) GetP(name string) (counter *Counter, ok bool) {
+	counter, ok = c[name]
+	if ok {
+		return
+	}
+	counter = &Counter{}
+	c[name] = counter
+	return
+}