add test cases

extensions/cachext/cached.go

@@ -68,14 +68,14 @@ func (c *CachedConfig) GetResult(ctx context.Context, out interface{}, strArgs [
 		c.cache.requestCounter.With(labels).Inc()
 	}
 	if data != nil {
-		if c.cacheNil && decodeIsNil(data) {
-			// 无法直接把out设置为nil，这里通过返回特殊的错误来表示nil。调用方需要判断
-			return Nil
-		}
 		if c.cache.hitCounter != nil {
 			// Increment hit counter.
 			c.cache.hitCounter.With(labels).Inc()
 		}
+		if c.cacheNil && decodeIsNil(data) {
+			// 无法直接把out设置为nil，这里通过返回特殊的错误来表示nil。调用方需要判断
+			return Nil
+		}
 		return decode(data, out)
 	}
 	res, err := c.getResult(ctx, strArgs, intArgs)

extensions/cachext/ext.go

@@ -85,8 +85,8 @@ func (c *CacheExt) Init(app *gobay.Application) error {
 		return errors.New("No backend found for cache_backend:" + backendConfig)
 	}
 	if config.GetBool("monitor_enable") {
-		c.requestCounter = initCacheRequestCounter()
-		c.hitCounter = initCacheHitCounter()
+		c.requestCounter = newCacheRequestCounter()
+		c.hitCounter = newCacheHitCounter()
 	}
 
 	c.initialized = true
@@ -257,7 +257,7 @@ func decodeIsNil(data interface{}) bool {
 }
 
 // Create a collector for total cache request counter
-func initCacheRequestCounter() *prometheus.CounterVec {
+func newCacheRequestCounter() *prometheus.CounterVec {
 	return promauto.NewCounterVec(
 		prometheus.CounterOpts{
 			Name: "cache_request_counter",
@@ -268,7 +268,7 @@ func initCacheRequestCounter() *prometheus.CounterVec {
 }
 
 // Create a collector for cache hit counter
-func initCacheHitCounter() *prometheus.CounterVec {
+func newCacheHitCounter() *prometheus.CounterVec {
 	return promauto.NewCounterVec(
 		prometheus.CounterOpts{
 			Name: "cache_hit_counter",

extensions/cachext/ext_test.go

@@ -3,13 +3,19 @@ package cachext_test
 import (
 	"context"
 	"fmt"
+	"io/ioutil"
+	"log"
 	"strings"
 	"testing"
 	"time"
 
+	"net/http"
+
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/shanbay/gobay"
 	"github.com/shanbay/gobay/extensions/cachext"
 	_ "github.com/shanbay/gobay/extensions/cachext/backend/memory"
+	"github.com/stretchr/testify/assert"
 )
 
 func ExampleCacheExt_Set() {
@@ -577,3 +583,52 @@ func Benchmark_Cached(b *testing.B) {
 		}
 	}
 }
+
+func TestCacheExt_Cached_Monitor(t *testing.T) {
+	// 准备数据
+	cache := &cachext.CacheExt{NS: "cache_"}
+	exts := map[gobay.Key]gobay.Extension{
+		"cache": cache,
+	}
+	_, err := gobay.CreateApp("../../testdata/", "cachemonitored", exts)
+	assert.Nil(t, err)
+
+	fetchMetricData := func() string {
+		resp, err := http.Get("http://localhost:2112/metrics")
+		if err != nil {
+			t.Error(err)
+		}
+		defer resp.Body.Close()
+		rawData, err := ioutil.ReadAll(resp.Body)
+		if err != nil {
+			t.Error(err)
+		}
+		return string(rawData)
+	}
+
+	go func() {
+		http.Handle("/metrics", promhttp.Handler())
+		if err := http.ListenAndServe(":2112", nil); err != nil {
+			log.Fatalf("error when start prometheus server: %v\n", err)
+		}
+	}()
+
+	// Cache method
+	f_str := func(_ context.Context, keys []string, args []int64) (interface{}, error) {
+		return keys[0], nil
+	}
+	c_f_str := cache.Cached("f_str", f_str, cachext.WithTTL(10*time.Second))
+	str := ""
+
+	// Get result from function
+	c_f_str.GetResult(context.Background(), &str, []string{"hello"}, []int64{})
+	data := fetchMetricData()
+	assert.Contains(t, data, `cache_request_counter{func_name="f_str",prefix_name="github"} 1`)
+	assert.NotContains(t, data, `cache_hit_counter`)
+
+	// Get result from cache
+	c_f_str.GetResult(context.Background(), &str, []string{"hello"}, []int64{})
+	data = fetchMetricData()
+	assert.Contains(t, data, `cache_request_counter{func_name="f_str",prefix_name="github"} 2`)
+	assert.Contains(t, data, `cache_hit_counter{func_name="f_str",prefix_name="github"} 1`)
+}

testdata/config.yaml

@@ -76,6 +76,9 @@ grpcnoretry:
 grpcmocked:
   <<: *defaults
   stub_health_mocked: true
+cachemonitored:
+  <<: *defaults
+  cache_monitor_enable: true
 development:
   <<: *defaults
 production: