refactoring: move metrics to metrics.go

Author: Stumble

cache.go

@@ -13,15 +13,12 @@ import (
 	"github.com/coocood/freecache"
 	"github.com/go-redis/redis/v8"
 	"github.com/klauspost/compress/s2"
-	"github.com/prometheus/client_golang/prometheus"
 	"github.com/rs/zerolog/log"
 	uuid "github.com/satori/go.uuid"
 	"github.com/vmihailenco/msgpack/v5"
 	"golang.org/x/sync/singleflight"
 )
 
-var _ = log.Logger
-
 const (
 	lockSuffix = "_LOCK"
 	delimiter  = "~|~"
@@ -50,10 +47,6 @@ const (
 	s2Compression        = 0x1
 )
 
-var (
-	getNow = time.Now
-)
-
 var (
 	// ErrTimeout is timeout error
 	ErrTimeout = errors.New("timeout")
@@ -65,6 +58,10 @@ var (
 	ErrTypeMismatch = errors.New("value type mismatches cached type")
 )
 
+var (
+	getNow = time.Now
+)
+
 // SetNowFunc is a helper function to replace time.Now(), usually used for testing.
 func SetNowFunc(f func() time.Time) { getNow = f }
 
@@ -81,76 +78,6 @@ type ValueBytesExpiredAt struct {
 	ExpiredAt  int64  `msgpack:"e,omitempty"` // UNIX timestamp in Milliseconds.
 }
 
-type metricSet struct {
-	Hit     *prometheus.CounterVec
-	Latency *prometheus.HistogramVec
-	Error   *prometheus.CounterVec
-}
-
-type metricHitLabel string
-type metricErrLabel string
-
-var (
-	hitLabels = []string{"hit"}
-	// metrics hit labels
-	hitLabelMemory metricHitLabel = "mem"
-	hitLabelRedis  metricHitLabel = "redis"
-	hitLabelDB     metricHitLabel = "db"
-	// The unit is ms.
-	latencyBucket = []float64{
-		1, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096}
-
-	errLabels = []string{"when"}
-	// metrics error labels
-	errLabelSetRedis              metricErrLabel = "set_redis"
-	errLabelSetMemCache           metricErrLabel = "set_mem_cache"
-	errLabelInvalidate            metricErrLabel = "invalidate_error"
-	errLabelMemoryUnmarshalFailed metricErrLabel = "mem_unmarshal_failed"
-	errLabelRedisUnmarshalFailed  metricErrLabel = "redis_unmarshal_failed"
-)
-
-func newMetricSet(appName string) *metricSet {
-	return &metricSet{
-		Hit: prometheus.NewCounterVec(
-			prometheus.CounterOpts{
-				Name: fmt.Sprintf("%s_dcache_hit_total", appName),
-				Help: "how many hits of 3 different operations: {mem, redis, db}.",
-			}, hitLabels),
-		Latency: prometheus.NewHistogramVec(
-			prometheus.HistogramOpts{
-				Name:    fmt.Sprintf("%s_dcache_latency_milliseconds", appName),
-				Help:    "Cache read latency in milliseconds",
-				Buckets: latencyBucket,
-			}, hitLabels),
-		Error: prometheus.NewCounterVec(
-			prometheus.CounterOpts{
-				Name: fmt.Sprintf("%s_dcache_error_total", appName),
-				Help: "how many internal errors happened",
-			}, errLabels),
-	}
-}
-
-func (m *metricSet) Register() {
-	err := prometheus.Register(m.Hit)
-	if err != nil {
-		log.Err(err).Msgf("failed to register prometheus Hit counters")
-	}
-	err = prometheus.Register(m.Latency)
-	if err != nil {
-		log.Err(err).Msgf("failed to register prometheus Latency histogram")
-	}
-	err = prometheus.Register(m.Error)
-	if err != nil {
-		log.Err(err).Msgf("failed to register prometheus Error counter")
-	}
-}
-
-func (m *metricSet) Unregister() {
-	prometheus.Unregister(m.Hit)
-	prometheus.Unregister(m.Error)
-	prometheus.Unregister(m.Latency)
-}
-
 // DCache implements cache.
 type DCache struct {
 	conn         redis.UniversalClient

metrics.go

@@ -0,0 +1,78 @@
+package dcache
+
+import (
+	"fmt"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/rs/zerolog/log"
+)
+
+type metricSet struct {
+	Hit     *prometheus.CounterVec
+	Latency *prometheus.HistogramVec
+	Error   *prometheus.CounterVec
+}
+
+type metricHitLabel string
+type metricErrLabel string
+
+var (
+	hitLabels = []string{"hit"}
+	// metrics hit labels
+	hitLabelMemory metricHitLabel = "mem"
+	hitLabelRedis  metricHitLabel = "redis"
+	hitLabelDB     metricHitLabel = "db"
+	// The unit is ms.
+	latencyBucket = []float64{
+		1, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096}
+
+	errLabels = []string{"when"}
+	// metrics error labels
+	errLabelSetRedis              metricErrLabel = "set_redis"
+	errLabelSetMemCache           metricErrLabel = "set_mem_cache"
+	errLabelInvalidate            metricErrLabel = "invalidate_error"
+	errLabelMemoryUnmarshalFailed metricErrLabel = "mem_unmarshal_failed"
+	errLabelRedisUnmarshalFailed  metricErrLabel = "redis_unmarshal_failed"
+)
+
+func newMetricSet(appName string) *metricSet {
+	return &metricSet{
+		Hit: prometheus.NewCounterVec(
+			prometheus.CounterOpts{
+				Name: fmt.Sprintf("%s_dcache_hit_total", appName),
+				Help: "how many hits of 3 different operations: {mem, redis, db}.",
+			}, hitLabels),
+		Latency: prometheus.NewHistogramVec(
+			prometheus.HistogramOpts{
+				Name:    fmt.Sprintf("%s_dcache_latency_milliseconds", appName),
+				Help:    "Cache read latency in milliseconds",
+				Buckets: latencyBucket,
+			}, hitLabels),
+		Error: prometheus.NewCounterVec(
+			prometheus.CounterOpts{
+				Name: fmt.Sprintf("%s_dcache_error_total", appName),
+				Help: "how many internal errors happened",
+			}, errLabels),
+	}
+}
+
+func (m *metricSet) Register() {
+	err := prometheus.Register(m.Hit)
+	if err != nil {
+		log.Err(err).Msgf("failed to register prometheus Hit counters")
+	}
+	err = prometheus.Register(m.Latency)
+	if err != nil {
+		log.Err(err).Msgf("failed to register prometheus Latency histogram")
+	}
+	err = prometheus.Register(m.Error)
+	if err != nil {
+		log.Err(err).Msgf("failed to register prometheus Error counter")
+	}
+}
+
+func (m *metricSet) Unregister() {
+	prometheus.Unregister(m.Hit)
+	prometheus.Unregister(m.Error)
+	prometheus.Unregister(m.Latency)
+}