Pull request 1799: AG-21072-stats-conf-race

Merge in DNS/adguard-home from AG-21072-stats-conf-race to master

Squashed commit of the following:

commit 26843b70ab8bfe0fa110c4156f2fd3f53ec5ee74
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Apr 4 20:30:22 2023 +0300

    all: imp docs, locks

commit 942a5baa9606376dd06a3ef3284c17133014f768
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Apr 4 19:15:18 2023 +0300

    stats: fix conf races

internal/querylog/qlog.go

@@ -12,7 +12,6 @@ import (
 	"github.com/AdguardTeam/AdGuardHome/internal/filtering"
 	"github.com/AdguardTeam/golibs/errors"
 	"github.com/AdguardTeam/golibs/log"
-	"github.com/AdguardTeam/golibs/stringutil"
 	"github.com/AdguardTeam/golibs/timeutil"
 	"github.com/miekg/dns"
 )
@@ -126,9 +125,7 @@ func (l *queryLog) WriteDiskConfig(c *Config) {
 	defer l.confMu.RUnlock()
 
 	*c = *l.conf
-
-	// TODO(a.garipov): Add stringutil.Set.Clone.
-	c.Ignored = stringutil.NewSet(l.conf.Ignored.Values()...)
+	c.Ignored = l.conf.Ignored.Clone()
 }
 
 // Clear memory buffer and remove log files

internal/querylog/querylog.go

@@ -33,6 +33,8 @@ type QueryLog interface {
 }
 
 // Config is the query log configuration structure.
+//
+// Do not alter any fields of this structure after using it.
 type Config struct {
 	// Ignored is the list of host names, which should not be written to log.
 	Ignored *stringutil.Set