Bench command in multisubject mode subject format improvement (#1177)

* Bench command in multisubject mode subject format improvement

When using nats bench in multisubject mode to generate messages in order to evaluate the amount of memory used by the indexes according to the number of subjects being stored in the stream it is more accurate if all the subjects have the same size. This achieves that by using padding 0 up to the length of the max number of subjects when creating the subjects.

Signed-off-by: Jean-Noël Moyne <[email protected]>

* Optimization

Signed-off-by: Jean-Noël Moyne <[email protected]>

---------

Signed-off-by: Jean-Noël Moyne <[email protected]>

cli/bench_command.go

@@ -62,6 +62,7 @@ type benchCmd struct {
 	fetchTimeout         bool
 	multiSubject         bool
 	multiSubjectMax      int
+	multisubjectFormat   string
 	deDuplication        bool
 	deDuplicationWindow  time.Duration
 	ack                  bool
@@ -453,7 +454,7 @@ func (c *benchCmd) getPublishSubject(number int) string {
 		if c.multiSubjectMax == 0 {
 			return c.subject + "." + strconv.Itoa(number)
 		} else {
-			return c.subject + "." + strconv.Itoa(number%c.multiSubjectMax)
+			return c.subject + "." + fmt.Sprintf(c.multisubjectFormat, number%c.multiSubjectMax)
 		}
 	} else {
 		return c.subject
@@ -1546,6 +1547,8 @@ func (c *benchCmd) coreNATSPublisher(nc *nats.Conn, progress *uiprogress.Bar, ms
 		})
 	}
 
+	c.multisubjectFormat = fmt.Sprintf("%%0%dd", len(strconv.Itoa(c.multiSubjectMax)))
+
 	for i := 0; i < numMsg; i++ {
 		if progress != nil {
 			progress.Incr()
@@ -1575,6 +1578,8 @@ func (c *benchCmd) coreNATSRequester(nc *nats.Conn, progress *uiprogress.Bar, ms
 		})
 	}
 
+	c.multisubjectFormat = fmt.Sprintf("%%0%dd", len(strconv.Itoa(c.multiSubjectMax)))
+
 	for i := 0; i < numMsg; i++ {
 		if progress != nil {
 			progress.Incr()
@@ -1610,6 +1615,8 @@ func (c *benchCmd) jsPublisher(nc *nats.Conn, progress *uiprogress.Bar, msg []by
 		})
 	}
 
+	c.multisubjectFormat = fmt.Sprintf("%%0%dd", len(strconv.Itoa(c.multiSubjectMax)))
+
 	if c.batchSize != 1 {
 		for i := 0; i < numMsg; {
 			state = "Publishing"