Add caching to minimize lookup time (closes #12)

api/v1/server.go

@@ -3,6 +3,7 @@ package api_v1
 import (
 	"context"
 	"net/http"
+	"time"
 
 	"git.ar21.de/yolokube/country-geo-locations/pkg/geoloc"
 	"github.com/go-chi/chi/v5"
@@ -49,16 +50,20 @@ func searchIPCtx(next http.Handler) http.Handler {
 				render.Render(w, r, errInvalidRequest(err))
 				return
 			}
-			for {
-				ipinfo, err = geoloc.SearchIPNet(ipnetnum)
-				if err != nil {
-					render.Render(w, r, errNotFound)
-					return
-				}
-				if ipinfo != nil {
-					break
-				}
-				ipnetnum = ipnetnum - 8
+
+			newipnet, found := geoloc.IPCache.Get(ipnetnum)
+			if found {
+				ipnetnum = newipnet
+			}
+
+			ipinfo, err = geoloc.SearchIPNet(ipnetnum)
+			if err != nil {
+				render.Render(w, r, errNotFound)
+				return
+			}
+
+			if !found {
+				geoloc.IPCache.Set(ipnetnum, ipinfo.IPNumFrom, 2*time.Minute)
 			}
 		}
 		ctx := context.WithValue(r.Context(), keyIPInfo, ipinfo)

main.go

@@ -32,6 +32,9 @@ func main() {
 	}
 	fmt.Println("Import data from file successful")
 
+	geoloc.IPCache = geoloc.NewCache()
+	fmt.Println("Cache created")
+
 	r := chi.NewRouter()
 	r.Use(middleware.RequestID)
 	r.Use(middleware.Logger)

pkg/geoloc/cache.go

@@ -0,0 +1,29 @@
+package geoloc
+
+import (
+	"sync"
+	"time"
+)
+
+var IPCache *Cache
+
+type Cache struct {
+	store sync.Map
+}
+
+func NewCache() *Cache {
+	return &Cache{}
+}
+
+func (c *Cache) Set(key, value uint, ttl time.Duration) {
+	c.store.Store(key, value)
+	time.AfterFunc(ttl, func() {
+		c.store.Delete(key)
+	})
+}
+
+func (c *Cache) Get(key uint) (uint, bool) {
+	output, _ := c.store.Load(key)
+	value, ok := output.(uint)
+	return value, ok
+}