Use Redis for blocked servers list

src/util.go

@@ -5,68 +5,18 @@ import (
 	_ "embed"
 	"encoding/hex"
 	"fmt"
-	"io"
-	"net/http"
 	"regexp"
 	"strconv"
 	"strings"
-	"sync"
 )
 
 var (
 	//go:embed icon.png
-	defaultIconBytes []byte
-	blockedServers   *MutexArray[string] = nil
-	ipAddressRegExp  *regexp.Regexp      = regexp.MustCompile(`^\d{1,3}(\.\d{1,3}){3}$`)
+	defaultIcon     []byte
+	ipAddressRegExp *regexp.Regexp = regexp.MustCompile(`^\d{1,3}(\.\d{1,3}){3}$`)
 )
 
-type MutexArray[K comparable] struct {
-	List  []K
-	Mutex *sync.Mutex
-}
-
-func (m *MutexArray[K]) Has(value K) bool {
-	m.Mutex.Lock()
-
-	defer m.Mutex.Unlock()
-
-	for _, v := range m.List {
-		if v == value {
-			return true
-		}
-	}
-
-	return false
-}
-
-func GetBlockedServerList() error {
-	resp, err := http.Get("https://sessionserver.mojang.com/blockedservers")
-
-	if err != nil {
-		return err
-	}
-
-	if resp.StatusCode != http.StatusOK {
-		return fmt.Errorf("unexpected status code: %d", resp.StatusCode)
-	}
-
-	defer resp.Body.Close()
-
-	body, err := io.ReadAll(resp.Body)
-
-	if err != nil {
-		return err
-	}
-
-	blockedServers = &MutexArray[string]{
-		List:  strings.Split(string(body), "\n"),
-		Mutex: &sync.Mutex{},
-	}
-
-	return nil
-}
-
-func IsBlockedAddress(address string) bool {
+func IsBlockedAddress(address string) (bool, error) {
 	split := strings.Split(strings.ToLower(address), ".")
 
 	isIPAddress := ipAddressRegExp.MatchString(address)
@@ -94,14 +44,19 @@ func IsBlockedAddress(address string) bool {
 		}
 
 		newAddressBytes := sha1.Sum([]byte(newAddress))
-		newAddressHash := hex.EncodeToString(newAddressBytes[:])
 
-		if blockedServers.Has(newAddressHash) {
-			return true
+		exists, err := r.Exists(fmt.Sprintf("blocked:%s", hex.EncodeToString(newAddressBytes[:])))
+
+		if err != nil {
+			return false, err
+		}
+
+		if exists {
+			return true, nil
 		}
 	}
 
-	return false
+	return false, nil
 }
 
 func ParseAddress(address string, defaultPort uint16) (string, uint16, error) {