refactoring

.gitignore

@@ -0,0 +1 @@
+.idea

README.md

@@ -1,8 +1,16 @@
 # saramaprom
-This is a prometheus metrics reporter for the sarama library. 
-It is based on is based on https://github.com/deathowl/go-metrics-prometheus library.
+[![GoDoc](https://godoc.org/github.com/iimos/saramaprom?status.png)](http://godoc.org/github.com/iimos/saramaprom)
+[![Go Report](https://goreportcard.com/badge/github.com/iimos/saramaprom)](https://goreportcard.com/report/github.com/iimos/saramaprom)
 
-Usage:
+This is a prometheus metrics reporter for the [sarama](https://github.com/Shopify/sarama) library. 
+It is based on https://github.com/deathowl/go-metrics-prometheus library.
+
+## Installation
+```console
+go get github.com/iimos/saramaprom
+```
+
+## Usage
 
 ```go
 import (
@@ -39,4 +47,8 @@ type Options struct {
 	// Debug turns on debug logging.
 	Debug bool
 }
-```
+```
+
+## Requirements
+
+Go 1.13 or above.

saramaprom.go

@@ -9,6 +9,7 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 )
 
+// Options holds optional params for ExportMetrics.
 type Options struct {
 	// PrometheusRegistry is prometheus registry. Default prometheus.DefaultRegisterer.
 	PrometheusRegistry prometheus.Registerer
@@ -31,7 +32,7 @@ type Options struct {
 	Debug bool
 }
 
-// ExportMetric exports metrics from metricsRegistry to prometheus registry.
+// ExportMetrics exports metrics from go-metrics to prometheus.
 func ExportMetrics(ctx context.Context, metricsRegistry MetricsRegistry, opt Options) error {
 	if opt.PrometheusRegistry == nil {
 		opt.PrometheusRegistry = prometheus.DefaultRegisterer
@@ -84,6 +85,8 @@ func ExportMetrics(ctx context.Context, metricsRegistry MetricsRegistry, opt Opt
 	return nil
 }
 
+// MetricsRegistry is an interface for 'github.com/rcrowley/go-metrics'.Registry
+// which is used for metrics in sarama.
 type MetricsRegistry interface {
 	Each(func(name string, i interface{}))
 }