modernizes for loop in cmd/, internal/ (#21309)

internal/dsync/drwmutex.go

@@ -381,7 +381,7 @@ func refreshLock(ctx context.Context, ds *Dsync, id, source string, quorum int)
 	lockNotFound, lockRefreshed := 0, 0
 	done := false
 
-	for i := 0; i < len(restClnts); i++ {
+	for range len(restClnts) {
 		select {
 		case refreshResult := <-ch:
 			if refreshResult.offline {

internal/event/targetlist.go

@@ -357,7 +357,7 @@ func (list *TargetList) startSendWorkers(workerCount int) {
 	if err != nil {
 		panic(err)
 	}
-	for i := 0; i < workerCount; i++ {
+	for range workerCount {
 		wk.Take()
 		go func() {
 			defer wk.Give()

internal/grid/connection.go

@@ -1041,7 +1041,7 @@ func (c *Connection) readStream(ctx context.Context, conn net.Conn, cancel conte
 		// Handle merged messages.
 		messages := int(m.Seq)
 		c.inMessages.Add(int64(messages))
-		for i := 0; i < messages; i++ {
+		for range messages {
 			if atomic.LoadUint32((*uint32)(&c.state)) != StateConnected {
 				return
 			}

internal/grid/debug.go

@@ -143,7 +143,7 @@ func (t *TestGrid) WaitAllConnect(ctx context.Context) {
 }
 
 func getHosts(n int) (hosts []string, listeners []net.Listener, err error) {
-	for i := 0; i < n; i++ {
+	for range n {
 		l, err := net.Listen("tcp", "127.0.0.1:0")
 		if err != nil {
 			if l, err = net.Listen("tcp6", "[::1]:0"); err != nil {

internal/grid/muxclient.go

@@ -574,7 +574,7 @@ func (m *muxClient) ack(seq uint32) {
 		return
 	}
 	available := cap(m.outBlock)
-	for i := 0; i < available; i++ {
+	for range available {
 		m.outBlock <- struct{}{}
 	}
 	m.acked = true

internal/grid/muxserver.go

@@ -130,7 +130,7 @@ func newMuxStream(ctx context.Context, msg message, c *Connection, handler Strea
 	// Fill outbound block.
 	// Each token represents a message that can be sent to the client without blocking.
 	// The client will refill the tokens as they confirm delivery of the messages.
-	for i := 0; i < outboundCap; i++ {
+	for range outboundCap {
 		m.outBlock <- struct{}{}
 	}
 

internal/s3select/csv/reader.go

@@ -230,7 +230,7 @@ func (r *Reader) startReaders(newReader func(io.Reader) *csv.Reader) error {
 	}()
 
 	// Start parsers
-	for i := 0; i < runtime.GOMAXPROCS(0); i++ {
+	for range runtime.GOMAXPROCS(0) {
 		go func() {
 			for in := range r.input {
 				if len(in.input) == 0 {

internal/s3select/json/preader.go

@@ -173,7 +173,7 @@ func (r *PReader) startReaders() {
 	}()
 
 	// Start parsers
-	for i := 0; i < runtime.GOMAXPROCS(0); i++ {
+	for range runtime.GOMAXPROCS(0) {
 		go func() {
 			for in := range r.input {
 				if len(in.input) == 0 {

internal/s3select/jstream/decoder.go

@@ -332,7 +332,7 @@ func (d *Decoder) u4() rune {
 	// logic taken from:
 	// github.com/buger/jsonparser/blob/master/escape.go#L20
 	var h [4]int
-	for i := 0; i < 4; i++ {
+	for i := range 4 {
 		c := d.next()
 		switch {
 		case c >= '0' && c <= '9':