From 3f5b19497c97aefb75a3dddd7eda8360688abddc Mon Sep 17 00:00:00 2001
From: Vasiliy Tolstov <v.tolstov@unistack.org>
Date: Sat, 9 Oct 2021 23:50:57 +0300
Subject: [PATCH] meter: add Clone method

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>
---
 meter/meter.go | 14 ++++++++++++++
 meter/noop.go  |  9 +++++++++
 2 files changed, 23 insertions(+)

diff --git a/meter/meter.go b/meter/meter.go
index 204022c2..286f08bc 100644
--- a/meter/meter.go
+++ b/meter/meter.go
@@ -28,17 +28,31 @@ var (
 
 // Meter is an interface for collecting and instrumenting metrics
 type Meter interface {
+	// Name returns meter name
 	Name() string
+	// Init initialize meter
 	Init(opts ...Option) error
+	// Clone create meter copy with new options
+	Clone(opts ...Option) Meter
+	// Counter get or create counter
 	Counter(name string, labels ...string) Counter
+	// FloatCounter get or create float counter
 	FloatCounter(name string, labels ...string) FloatCounter
+	// Gauge get or create gauge
 	Gauge(name string, fn func() float64, labels ...string) Gauge
+	// Set create new meter metrics set
 	Set(opts ...Option) Meter
+	// Histogram get or create histogram
 	Histogram(name string, labels ...string) Histogram
+	// Summary get or create summary
 	Summary(name string, labels ...string) Summary
+	// SummaryExt get or create summary with spcified quantiles and window time
 	SummaryExt(name string, window time.Duration, quantiles []float64, labels ...string) Summary
+	// Write writes metrics to io.Writer
 	Write(w io.Writer, opts ...Option) error
+	// Options returns meter options
 	Options() Options
+	// String return meter type
 	String() string
 }
 
diff --git a/meter/noop.go b/meter/noop.go
index 875310c4..a1b47a94 100644
--- a/meter/noop.go
+++ b/meter/noop.go
@@ -15,6 +15,15 @@ func NewMeter(opts ...Option) Meter {
 	return &noopMeter{opts: NewOptions(opts...)}
 }
 
+// Clone return old meter with new options
+func (r *noopMeter) Clone(opts ...Option) Meter {
+	options := r.opts
+	for _, o := range opts {
+		o(&options)
+	}
+	return &noopMeter{opts: options}
+}
+
 func (r *noopMeter) Name() string {
 	return r.opts.Name
 }