tmbench: Make tx size configurable

* Make the parameter for tx size in bytes -s <size>, w/ default value 250

tm-bench/README.md

@@ -34,7 +34,7 @@ with the last command being in a seperate window.
 
 ## Usage
 
-    tm-bench [-c 1] [-T 10] [-r 1000] [endpoints]
+    tm-bench [-c 1] [-T 10] [-r 1000] [-s 250] [endpoints]
 
     Examples:
             tm-bench localhost:26657
@@ -45,6 +45,8 @@ with the last command being in a seperate window.
             Connections to keep open per endpoint (default 1)
       -r int
             Txs per second to send in a connection (default 1000)
+      -s int
+            Size per tx in bytes
       -v    Verbose output
 
 ## Development

tm-bench/main.go

@@ -27,13 +27,14 @@ type statistics struct {
 }
 
 func main() {
-	var duration, txsRate, connections int
+	var duration, txsRate, connections, txSize int
 	var verbose bool
 	var outputFormat, broadcastTxMethod string
 
 	flag.IntVar(&connections, "c", 1, "Connections to keep open per endpoint")
 	flag.IntVar(&duration, "T", 10, "Exit after the specified amount of time in seconds")
 	flag.IntVar(&txsRate, "r", 1000, "Txs per second to send in a connection")
+	flag.IntVar(&txSize, "s", 250, "The size of a transaction in bytes.")
 	flag.StringVar(&outputFormat, "output-format", "plain", "Output format: plain or json")
 	flag.StringVar(&broadcastTxMethod, "broadcast-tx-method", "async", "Broadcast method: async (no guarantees; fastest), sync (ensures tx is checked) or commit (ensures tx is checked and committed; slowest)")
 	flag.BoolVar(&verbose, "v", false, "Verbose output")
@@ -101,6 +102,7 @@ Examples:
 		endpoints,
 		connections,
 		txsRate,
+		txSize,
 		"broadcast_tx_"+broadcastTxMethod,
 	)
 
@@ -228,12 +230,13 @@ func startTransacters(
 	endpoints []string,
 	connections,
 	txsRate int,
+	txSize int,
 	broadcastTxMethod string,
 ) []*transacter {
 	transacters := make([]*transacter, len(endpoints))
 
 	for i, e := range endpoints {
-		t := newTransacter(e, connections, txsRate, broadcastTxMethod)
+		t := newTransacter(e, connections, txsRate, txSize, broadcastTxMethod)
 		t.SetLogger(logger)
 		if err := t.Start(); err != nil {
 			fmt.Fprintln(os.Stderr, err)

tm-bench/transacter.go

@@ -25,14 +25,12 @@ const (
 	sendTimeout = 10 * time.Second
 	// see https://github.com/tendermint/go-rpc/blob/develop/server/handlers.go#L313
 	pingPeriod = (30 * 9 / 10) * time.Second
-
-	// the size of a transaction in bytes.
-	txSize = 250
 )
 
 type transacter struct {
 	Target            string
 	Rate              int
+	Size              int
 	Connections       int
 	BroadcastTxMethod string
 
@@ -43,10 +41,11 @@ type transacter struct {
 	logger log.Logger
 }
 
-func newTransacter(target string, connections, rate int, broadcastTxMethod string) *transacter {
+func newTransacter(target string, connections, rate int, size int, broadcastTxMethod string) *transacter {
 	return &transacter{
 		Target:            target,
 		Rate:              rate,
+		Size:              size,
 		Connections:       connections,
 		BroadcastTxMethod: broadcastTxMethod,
 		conns:             make([]*websocket.Conn, connections),
@@ -152,7 +151,7 @@ func (t *transacter) sendLoop(connIndex int) {
 
 			for i := 0; i < t.Rate; i++ {
 				// each transaction embeds connection index, tx number and hash of the hostname
-				tx := generateTx(connIndex, txNumber, hostnameHash)
+				tx := generateTx(connIndex, txNumber, t.Size, hostnameHash)
 				paramsJSON, err := json.Marshal(map[string]interface{}{"tx": hex.EncodeToString(tx)})
 				if err != nil {
 					fmt.Printf("failed to encode params: %v\n", err)
@@ -207,7 +206,7 @@ func connect(host string) (*websocket.Conn, *http.Response, error) {
 	return websocket.DefaultDialer.Dial(u.String(), nil)
 }
 
-func generateTx(connIndex int, txNumber int, hostnameHash [md5.Size]byte) []byte {
+func generateTx(connIndex int, txNumber int, txSize int, hostnameHash [md5.Size]byte) []byte {
 	tx := make([]byte, txSize)
 
 	binary.PutUvarint(tx[:8], uint64(connIndex))