etag write to file

handle query before db loaded

internal/services/db_updater/downloader.go

@@ -4,12 +4,11 @@ import (
 	"github.com/go-resty/resty/v2"
 	"github.com/rs/zerolog/log"
 	"net/http"
+	"os"
 	"path"
 	"thuanle.me/ip-info/configs"
 )
 
-var etags = map[string]string{}
-
 func download(url string) bool {
 	log.Info().Str("url", url).Msg("Downloading DB")
 	filename := configs.GeoDbFolder + path.Base(url)
@@ -17,7 +16,7 @@ func download(url string) bool {
 	client := resty.New()
 	resp, err := client.R().
 		SetOutput(filename).
-		SetHeader("If-None-Match", etags[url]).
+		SetHeader("If-None-Match", readETag(filename)).
 		Get(url)
 
 	if err != nil {
@@ -28,15 +27,31 @@ func download(url string) bool {
 	}
 
 	if resp.StatusCode() == http.StatusOK {
-		etags[url] = resp.Header().Get("Etag")
+		writeETag(filename, resp.Header().Get("Etag"))
 	} else {
 		//log.Printf("No update needed: %v", resp.Status())
 		return false
 	}
 
 	log.Info().
-		Str("Etag", etags[url]).
 		Str("filename", filename).
 		Msg("Downloaded DB")
 	return true
 }
+
+// readETag reads the ETag from the file
+func readETag(baseFile string) string {
+	data, err := os.ReadFile(baseFile + ".etag")
+	if err != nil {
+		return ""
+	}
+	return string(data)
+}
+
+// writeETag writes the ETag to the file
+func writeETag(baseFile, etag string) {
+	err := os.WriteFile(baseFile+".etag", []byte(etag), 0644)
+	if err != nil {
+		log.Err(err).Msg("Failed to write ETag")
+	}
+}