stats: imp code

internal/stats/http.go

@@ -61,7 +61,7 @@ func (s *StatsCtx) handleStats(w http.ResponseWriter, r *http.Request) {
 		resp, ok = s.getData(uint32(s.limit.Hours()))
 	}()
 
-	s.logger.Debug("prepared data", "elapsed", time.Since(start))
+	s.logger.Debug("prepared data", "elapsed", timeutil.Duration{Duration: time.Since(start)})
 
 	if !ok {
 		// Don't bring the message to the lower case since it's a part of UI

internal/stats/stats.go

@@ -3,6 +3,7 @@
 package stats
 
 import (
+	"context"
 	"fmt"
 	"io"
 	"log/slog"
@@ -387,7 +388,11 @@ func (s *StatsCtx) openDB() (err error) {
 	db, err = bbolt.Open(s.filename, 0o644, nil)
 	if err != nil {
 		if err.Error() == "invalid argument" {
-			s.logger.Error("AdGuard Home cannot be initialized due to an incompatible file system.\nPlease read the explanation here: https://github.com/AdguardTeam/AdGuardHome/wiki/Getting-Started#limitations")
+			const lines = `AdGuard Home cannot be initialized due to an incompatible file system.
+Please read the explanation here: https://github.com/AdguardTeam/AdGuardHome/wiki/Getting-Started#limitations`
+
+			// TODO(s.chzhen):  Use passed context.
+			slogutil.PrintLines(context.TODO(), s.logger, slog.LevelError, "opening database", lines)
 		}
 
 		return err
@@ -597,8 +602,7 @@ func (s *StatsCtx) loadUnits(limit uint32) (units []*unitDB, curID uint32) {
 
 	if unitsLen := len(units); unitsLen != int(limit) {
 		// Should not happen.
-		s.logger.Error("number of loaded units not equal to limit", "loaded", unitsLen, "limit", limit)
+		panic(fmt.Errorf("loaded %d units when the desired number is %d", unitsLen, limit))
-		units = units[:limit]
 	}
 
 	return units, curID

internal/stats/stats_test.go

@@ -22,6 +22,7 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+// TODO(s.chzhen):  Remove once [aghhttp.Error] starts using slog.
 func TestMain(m *testing.M) {
 	testutil.DiscardLogOutput(m)
 }