add cache decorator

Author: zmh-program

README.md

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"github.com/go-redis/redis/v8"
 	"github.com/kataras/iris/v12"
@@ -23,10 +24,72 @@ func SetupCache() {
 	}
 }
 
-func SetCache(ctx iris.Context, key string, value interface{}) error {
+func SetCache(ctx iris.Context, key string, value string) error {
 	return cache.Set(ctx.Request().Context(), key, value, conf.Redis.Expiration).Err()
 }
 
-func GetCache(ctx iris.Context, key string) (string, error) {
-	return cache.Get(ctx.Request().Context(), key).Result()
+func GetCache(ctx iris.Context, key string) (val string, ok bool) {
+	val, err := cache.Get(ctx.Request().Context(), key).Result()
+	if err == redis.Nil {
+		return "", false
+	} else if err != nil {
+		return "", false
+	} else if val == "" {
+		return "", false
+	}
+	return val, true
+}
+
+func SetJSONCache(ctx iris.Context, key string, value interface{}) error {
+	val, err := json.Marshal(value)
+	if err != nil {
+		return err
+	}
+	return SetCache(ctx, key, string(val))
+}
+
+func GetJSONCache(ctx iris.Context, key string) (value iris.Map, ok bool) {
+	val, ok := GetCache(ctx, key)
+	if !ok {
+		return nil, false
+	}
+	err := json.Unmarshal([]byte(val), &value)
+	if err != nil {
+		return nil, false
+	}
+	return value, true
+}
+
+func GenerateKey(ctx iris.Context, keys ...string) string {
+	param := ""
+	for _, key := range keys {
+		value := ctx.Params().GetString(key)
+		param += fmt.Sprintf("%s=%s;", key, value)
+	}
+	return fmt.Sprintf("%s?%s", ctx.Path(), param)
+}
+
+// CachedHandler is a decorator for handlers to enable caching their response.
+func CachedHandler(h iris.Handler, params ...string) iris.Handler {
+	return func(ctx iris.Context) {
+		key := GenerateKey(ctx, params...)
+
+		result, ok := GetJSONCache(ctx, key)
+		if ok {
+			ctx.JSON(result)
+			return
+		}
+
+		h(ctx)
+	}
+}
+
+func EndBody(ctx iris.Context, value iris.Map, params ...string) {
+	err := SetJSONCache(ctx, GenerateKey(ctx, params...), value)
+	if err != nil {
+		logger.Errorf("Failed to set cache: %s", err.Error())
+		ThrowError(ctx, err.Error(), iris.StatusInternalServerError)
+		return
+	}
+	ctx.JSON(value)
 }

cache.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"fmt"
-	"github.com/sirupsen/logrus"
 	"github.com/spf13/viper"
 	"math/rand"
 	"os"
@@ -65,9 +64,9 @@ func ReadConfig() {
 
 	viper.SetConfigFile("config.yaml")
 	if err := viper.ReadInConfig(); err != nil {
-		logrus.Fatalf("Failed to read config file: %v", err)
+		logger.Fatalf("Failed to read config file: %v", err)
 	}
 	if err := viper.Unmarshal(&conf); err != nil {
-		logrus.Fatalf("Failed to unmarshal config file: %v", err)
+		logger.Fatalf("Failed to unmarshal config file: %v", err)
 	}
 }

conf.go

@@ -8,8 +8,8 @@ import (
 func RunServer() {
 	app := iris.Default()
 	{
-		app.Get("/user/{username:string}", UserAPI)
-		app.Get("/repo/{username:string}/{repo:string}", RepoAPI)
+		app.Get("/user/{username:string}", CachedHandler(UserAPI, "username"))
+		app.Get("/repo/{username:string}/{repo:string}", CachedHandler(RepoAPI, "username", "password"))
 	}
 	app.Listen(fmt.Sprintf(":%d", conf.Server.Port))
 }
@@ -20,7 +20,7 @@ func UserAPI(ctx iris.Context) {
 	if err != nil {
 		ThrowError(ctx, err.Error(), code)
 	} else {
-		ctx.JSON(data)
+		EndBody(ctx, data, "username")
 	}
 }
 
@@ -30,6 +30,6 @@ func RepoAPI(ctx iris.Context) {
 	if err != nil {
 		ThrowError(ctx, err.Error(), code)
 	} else {
-		ctx.JSON(data)
+		EndBody(ctx, data, "username", "repo")
 	}
 }