trace2: use 'zap.Duration' to log elapsed times

Rather than log durations as 'Float64' of the duration's '.Seconds()', use
'zap.Duration()' directly and configure the logger to report durations in
units of seconds.

Signed-off-by: Victoria Dye <[email protected]>

Author: vdye

internal/log/trace2.go

@@ -88,6 +88,9 @@ func createTrace2ZapLogger() *zap.Logger {
 		},
 	)
 
+	// Ensure durations are logged in units of seconds
+	loggerConfig.EncoderConfig.EncodeDuration = zapcore.SecondsDurationEncoder
+
 	// Re-purpose the "message" to represent the (always-present) "event" key
 	loggerConfig.EncoderConfig.MessageKey = "event"
 
@@ -108,13 +111,13 @@ func NewTrace2() traceLoggerInternal {
 type fieldList []zap.Field
 
 func (l fieldList) withTime() fieldList {
-	return append(l, zap.Float64("t_abs", time.Since(globalStart).Seconds()))
+	return append(l, zap.Duration("t_abs", time.Since(globalStart)))
 }
 
 func (l fieldList) withNesting(r trace2Region, includeTRel bool) fieldList {
 	l = append(l, zap.Int("nesting", r.level))
 	if includeTRel {
-		l = append(l, zap.Float64("t_rel", time.Since(r.tStart).Seconds()))
+		l = append(l, zap.Duration("t_rel", time.Since(r.tStart)))
 	}
 	return l
 }