log: add benchmark for handler.Log (#494)

Updates #480

log/benchmark_test.go

@@ -0,0 +1,35 @@
+package log
+
+import (
+	"io"
+	"testing"
+
+	"github.com/cosmos/cosmos-sdk/server"
+	ethlog "github.com/ethereum/go-ethereum/log"
+	"github.com/rs/zerolog"
+	"github.com/tendermint/tendermint/types/time"
+)
+
+func BenchmarkHandler_Log(b *testing.B) {
+	logger := &server.ZeroLogWrapper{
+		Logger: zerolog.New(io.Discard).Level(zerolog.DebugLevel).With().Timestamp().Logger(),
+	}
+	h := NewHandler(logger)
+
+	b.ResetTimer()
+	b.ReportAllocs()
+
+	for i := 0; i < b.N; i++ {
+		h.Log(&ethlog.Record{
+			Time: time.Now().UTC(),
+			Lvl:  ethlog.LvlCrit,
+			Msg:  "critical error",
+			KeyNames: ethlog.RecordKeyNames{
+				Time: timeKey,
+				Msg:  msgKey,
+				Lvl:  lvlKey,
+				Ctx:  ctxKey,
+			},
+		})
+	}
+}