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)