Pull request: all: add string set

Merge in DNS/adguard-home from add-strset to master

Squashed commit of the following:

commit 2500df1805dee425eafd0503983ec631de02af0b
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Apr 20 15:09:59 2021 +0300

    all: add string set

internal/home/clients.go

@@ -83,7 +83,7 @@ type clientsContainer struct {
 	ipToRC  map[string]*RuntimeClient // IP -> runtime client
 	lock    sync.Mutex
 
-	allTags map[string]bool
+	allTags *aghstrings.Set
 
 	// dhcpServer is used for looking up clients IP addresses by MAC addresses
 	dhcpServer *dhcpd.Server
@@ -111,10 +111,7 @@ func (clients *clientsContainer) Init(
 	clients.idIndex = make(map[string]*Client)
 	clients.ipToRC = make(map[string]*RuntimeClient)
 
-	clients.allTags = make(map[string]bool)
-	for _, t := range clientTags {
-		clients.allTags[t] = false
-	}
+	clients.allTags = aghstrings.NewSet(clientTags...)
 
 	clients.dhcpServer = dhcpServer
 	clients.etcHosts = etcHosts
@@ -163,9 +160,8 @@ type clientObject struct {
 	Upstreams []string `yaml:"upstreams"`
 }
 
-func (clients *clientsContainer) tagKnown(tag string) bool {
-	_, ok := clients.allTags[tag]
-	return ok
+func (clients *clientsContainer) tagKnown(tag string) (ok bool) {
+	return clients.allTags.Has(tag)
 }
 
 func (clients *clientsContainer) addFromConfig(objects []clientObject) {

internal/home/i18n.go

@@ -6,52 +6,46 @@ import (
 	"net/http"
 	"strings"
 
+	"github.com/AdguardTeam/AdGuardHome/internal/aghstrings"
 	"github.com/AdguardTeam/golibs/log"
 )
 
-// --------------------
-// internationalization
-// --------------------
-var allowedLanguages = map[string]bool{
-	"be":    true,
-	"bg":    true,
-	"cs":    true,
-	"da":    true,
-	"de":    true,
-	"en":    true,
-	"es":    true,
-	"fa":    true,
-	"fr":    true,
-	"hr":    true,
-	"hu":    true,
-	"id":    true,
-	"it":    true,
-	"ja":    true,
-	"ko":    true,
-	"nl":    true,
-	"no":    true,
-	"pl":    true,
-	"pt-br": true,
-	"pt-pt": true,
-	"ro":    true,
-	"ru":    true,
-	"si-lk": true,
-	"sk":    true,
-	"sl":    true,
-	"sr-cs": true,
-	"sv":    true,
-	"th":    true,
-	"tr":    true,
-	"vi":    true,
-	"zh-cn": true,
-	"zh-hk": true,
-	"zh-tw": true,
-}
-
-func isLanguageAllowed(language string) bool {
-	l := strings.ToLower(language)
-	return allowedLanguages[l]
-}
+// TODO(a.garipov): Get rid of a global variable?
+var allowedLanguages = aghstrings.NewSet(
+	"be",
+	"bg",
+	"cs",
+	"da",
+	"de",
+	"en",
+	"es",
+	"fa",
+	"fr",
+	"hr",
+	"hu",
+	"id",
+	"it",
+	"ja",
+	"ko",
+	"nl",
+	"no",
+	"pl",
+	"pt-br",
+	"pt-pt",
+	"ro",
+	"ru",
+	"si-lk",
+	"sk",
+	"sl",
+	"sr-cs",
+	"sv",
+	"th",
+	"tr",
+	"vi",
+	"zh-cn",
+	"zh-hk",
+	"zh-tw",
+)
 
 func handleI18nCurrentLanguage(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "text/plain")
@@ -80,12 +74,15 @@ func handleI18nChangeLanguage(w http.ResponseWriter, r *http.Request) {
 		msg := "empty language specified"
 		log.Println(msg)
 		http.Error(w, msg, http.StatusBadRequest)
+
 		return
 	}
-	if !isLanguageAllowed(language) {
+
+	if !allowedLanguages.Has(language) {
 		msg := fmt.Sprintf("unknown language specified: %s", language)
 		log.Println(msg)
 		http.Error(w, msg, http.StatusBadRequest)
+
 		return
 	}
 

internal/home/rdns_test.go

@@ -9,6 +9,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/AdguardTeam/AdGuardHome/internal/aghstrings"
 	"github.com/AdguardTeam/AdGuardHome/internal/aghtest"
 	"github.com/AdguardTeam/dnsproxy/upstream"
 	"github.com/AdguardTeam/golibs/cache"
@@ -82,7 +83,7 @@ func TestRDNS_Begin(t *testing.T) {
 				list:    map[string]*Client{},
 				idIndex: tc.cliIDIndex,
 				ipToRC:  map[string]*RuntimeClient{},
-				allTags: map[string]bool{},
+				allTags: aghstrings.NewSet(),
 			},
 		}
 		ipCache.Clear()
@@ -172,7 +173,7 @@ func TestRDNS_WorkerLoop(t *testing.T) {
 			list:    map[string]*Client{},
 			idIndex: map[string]*Client{},
 			ipToRC:  map[string]*RuntimeClient{},
-			allTags: map[string]bool{},
+			allTags: aghstrings.NewSet(),
 		}
 		ch := make(chan net.IP)
 		rdns := &RDNS{