/*
closeSconn closes a stompngo Connection.
*/
func closeSconn(n net.Conn, conn *stompngo.Connection) {
ltag := tag + "-closesconn"
// Standard example disconnect sequence
e := sngecomm.CommonDisconnect(n, conn, exampid, ltag, ll)
if e != nil {
ll.Fatalf("%stag:%s connsess:%s disconnect_error error:%s\n",
exampid, ltag, conn.Session(),
e.Error()) // Handle this ......
}
return
}
// Send messages to a particular queue
func sender(conn *stompngo.Connection, qn, nmsgs int) {
ltag := tag + "-sender"
qns := fmt.Sprintf("%d", qn) // queue number
d := sngecomm.Dest() + "." + qns
ll.Printf("%stag:%s connsess:%s starts qn:%d nmsgs:%d d:%s\n",
exampid, ltag, conn.Session(),
qn, nmsgs, d)
//
wh := stompngo.Headers{"destination", d,
"qnum", qns} // send Headers
if senv.Persistent() {
wh = wh.Add("persistent", "true")
}
//
tmr := time.NewTimer(100 * time.Hour)
// Send loop
for i := 1; i <= nmsgs; i++ {
si := fmt.Sprintf("%d", i)
sh := append(wh, "msgnum", si)
// Generate a message to send ...............
ll.Printf("%stag:%s connsess:%s message qns:%s si:%s\n",
exampid, ltag, conn.Session(),
qns, si)
e := conn.Send(sh, string(sngecomm.Partial()))
if e != nil {
ll.Fatalf("%stag:%s connsess:%s send_error qnum:%v error:%v",
exampid, ltag, conn.Session(),
qn, e.Error()) // Handle this ......
}
if i == nmsgs {
break
}
if sw {
runtime.Gosched() // yield for this example
dt := time.Duration(sngecomm.ValueBetween(min, max, sf))
ll.Printf("%stag:%s connsess:%s send_stagger dt:%v qns:%s\n",
exampid, ltag, conn.Session(),
dt, qns)
tmr.Reset(dt)
_ = <-tmr.C
}
}
// Sending is done
ll.Printf("%stag:%s connsess:%s sender_ends qn:%d nmsgs:%d\n",
exampid, ltag, conn.Session(),
qn, nmsgs)
wgs.Done()
}
/*
runSender sends all messages to a specified queue.
*/
func runSender(conn *stompngo.Connection, qns string) {
ltag := tag + "-runsender"
d := sngecomm.Dest() + "." + qns
id := stompngo.Uuid() // A unique sender id
ll.Printf("%stag:%s connsess:%s start id:%s dest:%s\n",
exampid, ltag, conn.Session(),
id, d)
wh := stompngo.Headers{"destination", d, "senderId", id,
"qnum", qns} // basic send Headers
if senv.Persistent() {
wh = wh.Add("persistent", "true")
}
tmr := time.NewTimer(100 * time.Hour)
nmsgs := senv.Nmsgs()
for mc := 1; mc <= nmsgs; mc++ {
sh := append(wh, "msgnum", fmt.Sprintf("%d", mc))
// Generate a message to send ...............
ll.Printf("%stag:%s connsess:%s send id:%s qns:%s mc:%d\n",
exampid, ltag, conn.Session(),
id, qns, mc)
e := conn.Send(sh, string(sngecomm.Partial()))
if e != nil {
ll.Fatalf("%stag:%s connsess:%s send_error qns:%v error:%v",
exampid, ltag, conn.Session(),
qns, e.Error()) // Handle this ......
}
if mc == nmsgs {
break
}
if sw {
dt := time.Duration(sngecomm.ValueBetween(min, max, sf))
ll.Printf("%stag:%s connsess:%s send_stagger dt:%v qns:%s mc:%d\n",
exampid, ltag, conn.Session(),
dt, qns, mc)
tmr.Reset(dt)
_ = <-tmr.C
runtime.Gosched()
}
}
ll.Printf("%stag:%s connsess:%s end id:%s dest:%s\n",
exampid, ltag, conn.Session(),
id, d)
//
wgs.Done()
}
/*
receiverConnection starts individual receivers for this connection.
*/
func receiverConnection(conn *stompngo.Connection, cn, qpc int) {
ltag := tag + "-receiverconnection"
ll.Printf("%stag:%s connsess:%s starts cn:%d qpc:%d\n",
exampid, ltag, conn.Session(),
cn, qpc)
// cn -> a connection number: 1..n
// qpc -> destinations per connection
// Ex:
// 1, 2
// 2, 2
// 3, 2
// This code runs *once* for each connection
// These calcs are what causes a skip below. It is a safety valve to keep
// from starting one too many connections.
cb := cn - 1 // this connection number, zero based
q1 := qpc*cb + 1 // 1st queue number
ql := q1 + qpc - 1 // last queue number
if ql > sngecomm.Nqs() {
ql = sngecomm.Nqs() // truncate last if over max destinations
}
var wgrconn sync.WaitGroup
var skipped bool
if q1 <= ql {
ll.Printf("%stag:%s connsess:%s startq cn:%d q1:%d ql: %d\n",
exampid, ltag, conn.Session(),
cn, q1, ql)
skipped = false
} else {
// Skips are possible, at least with the current calling code, see above
ll.Printf("%stag:%s connsess:%s startskip cn:%d q1:%d ql: %d\n",
exampid, ltag, conn.Session(),
cn, q1, ql)
skipped = true
}
for q := q1; q <= ql; q++ {
wgrconn.Add(1)
go runReceive(conn, q, &wgrconn)
}
wgrconn.Wait()
//
ll.Printf("%stag:%s connsess:%s ends cn:%d qpc:%d skipped:%t\n",
exampid, ltag, conn.Session(),
cn, qpc, skipped)
wgr.Done()
}
// Common example disconnect logic
func CommonDisconnect(n net.Conn, conn *stompngo.Connection,
exampid, tag string,
l *log.Logger) error {
// Disconnect from the Stomp server
e := conn.Disconnect(stompngo.Headers{})
if e != nil {
return e
}
l.Printf("%stag:%s consess:%v common_disconnect_complete local_addr:%s remote_addr:%s\n",
exampid, tag, conn.Session(),
n.LocalAddr().String(), n.RemoteAddr().String())
// Close the network connection
e = n.Close()
if e != nil {
return e
}
// Parting messages
l.Printf("%stag:%s consess:%v common_disconnect_network_close_complete\n",
exampid, tag, conn.Session())
l.Printf("%stag:%s consess:%v common_disconnect_ends\n",
exampid, tag, conn.Session())
//
return nil
}
func sendMessages(conn *stompngo.Connection, qnum int, nc net.Conn) {
ltag := tag + "-sendmessages"
qns := fmt.Sprintf("%d", qnum) // queue number
d := sngecomm.Dest() + "." + qns
ll.Printf("%stag:%s connsess:%s start d:%s qnum:%d\n",
exampid, ltag, conn.Session(),
d, qnum)
wh := stompngo.Headers{"destination", d,
"qnum", qns} // send Headers
if senv.Persistent() {
wh = wh.Add("persistent", "true")
}
//
tmr := time.NewTimer(100 * time.Hour)
// Send messages
for mc := 1; mc <= nmsgs; mc++ {
mcs := fmt.Sprintf("%d", mc)
sh := append(wh, "msgnum", mcs)
// Generate a message to send ...............
ll.Printf("%stag:%s connsess:%s message mc:%d qnum:%d\n",
exampid, ltag, conn.Session(),
mc, qnum)
e := conn.Send(sh, string(sngecomm.Partial()))
if e != nil {
ll.Fatalf("%stag:%s connsess:%s send_error qnum:%v error:%v",
exampid, ltag, conn.Session(),
qnum, e.Error()) // Handle this ......
}
if mc == nmsgs {
break
}
if sw {
runtime.Gosched() // yield for this example
dt := time.Duration(sngecomm.ValueBetween(min, max, sf))
ll.Printf("%stag:%s connsess:%s send_stagger dt:%v qnum:%s mc:%d\n",
exampid, ltag, conn.Session(),
dt, qnum, mc)
tmr.Reset(dt)
_ = <-tmr.C
}
}
}
func recv(conn *stompngo.Connection, s int) {
ltag := tag + "-recv"
ll.Printf("%stag:%s connsess:%s receiver_starts s:%d\n",
exampid, ltag, conn.Session(),
s)
// Setup Headers ...
id := stompngo.Uuid() // Use package convenience function for unique ID
d := sngecomm.Dest()
ackMode = sngecomm.AckMode() // get ack mode
pbc := sngecomm.Pbc() // Print byte count
sc := sngecomm.HandleSubscribe(conn, d, id, ackMode)
// Receive loop.
mc := 0
var md stompngo.MessageData
for {
select {
case md = <-sc: // Read a messagedata struct, with a MESSAGE frame
case md = <-conn.MessageData: // Read a messagedata struct, with a ERROR/RECEIPT frame
// Frames RECEIPT or ERROR not expected here
ll.Fatalf("%stag:%s connsess:%s bad_frame md:%v",
exampid, ltag, conn.Session(),
md) // Handle this ......
}
//
mc++
if md.Error != nil {
ll.Fatalf("%stag:%s connsess:%s error_read error:%v",
exampid, ltag, conn.Session(),
md.Error) // Handle this ......
}
ll.Printf("%stag:%s connsess:%s received_message s:%d id:%s mc:%d\n",
exampid, ltag, conn.Session(),
s, id, mc)
if pbc > 0 {
maxlen := pbc
if len(md.Message.Body) < maxlen {
maxlen = len(md.Message.Body)
}
ss := string(md.Message.Body[0:maxlen])
ll.Printf("%stag:%s connsess:%s payload body:%s\n",
exampid, tag, conn.Session(),
ss)
}
// time.Sleep(3 * time.Second) // A very arbitrary number
// time.Sleep(500 * time.Millisecond) // A very arbitrary number
runtime.Gosched()
time.Sleep(1500 * time.Millisecond) // A very arbitrary number
runtime.Gosched()
if ackMode != "auto" {
sngecomm.HandleAck(conn, md.Message.Headers, id)
ll.Printf("%stag:%s connsess:%s ack_complete s:%d id:%s mc:%d\n",
exampid, ltag, conn.Session(),
s, id, mc)
}
runtime.Gosched()
}
}
/*
runReceive receives all messages from a specified queue.
*/
func runReceive(conn *stompngo.Connection, q int, w *sync.WaitGroup) {
ltag := tag + "-runreceive"
qns := fmt.Sprintf("%d", q) // queue number
id := stompngo.Uuid() // A unique subscription ID
d := sngecomm.Dest() + "." + qns
ll.Printf("%stag:%s connsess:%s starts id:%s qns:%s d:%s\n",
exampid, ltag, conn.Session(),
id, qns, d)
// Subscribe (use common helper)
sc := sngecomm.HandleSubscribe(conn, d, id, sngecomm.AckMode())
ll.Printf("%stag:%s connsess:%s subscribe_done id:%s qns:%s d:%s\n",
exampid, ltag, conn.Session(),
id, qns, d)
//
tmr := time.NewTimer(100 * time.Hour)
pbc := sngecomm.Pbc() // Print byte count
nmsgs := senv.Nmsgs()
// Receive loop
var md stompngo.MessageData
for mc := 1; mc <= nmsgs; mc++ {
ll.Printf("%stag:%s connsess:%s chanchek id:%s qns:%s lensc:%d capsc:%d\n",
exampid, ltag, conn.Session(),
id, qns, len(sc), cap(sc))
select {
case md = <-sc:
case md = <-conn.MessageData:
// Frames RECEIPT or ERROR not expected here
ll.Fatalf("%stag:%s connsess:%s send_error qns:%v md:%v",
exampid, ltag, conn.Session(),
qns, md) // Handle this ......
}
if md.Error != nil {
ll.Fatalf("%stag:%s connsess:%s receive_error qns:%v error:%v\n",
exampid, ltag, conn.Session(),
qns, md.Error)
}
// Process the inbound message .................
ll.Printf("%stag:%s connsess:%s inbound id:%s qns:%s mc:%d\n",
exampid, ltag, conn.Session(),
id, qns, mc)
// Sanity check the message Command, and the queue and message numbers
mns := fmt.Sprintf("%d", mc) // string message number
if md.Message.Command != stompngo.MESSAGE {
ll.Fatalf("%stag:%s connsess:%s bad_frame qns:%s mc:%d md:%v\n",
exampid, ltag, conn.Session(),
qns, mc, md)
}
if !md.Message.Headers.ContainsKV("qnum", qns) || !md.Message.Headers.ContainsKV("msgnum", mns) {
ll.Fatalf("%stag:%s connsess:%s dirty_message qns:%v msgnum:%v md:%v",
exampid, tag, conn.Session(),
qns, mns, md) // Handle this ......
}
sl := len(md.Message.Body)
if pbc > 0 {
sl = pbc
if len(md.Message.Body) < sl {
sl = len(md.Message.Body)
}
}
ll.Printf("%stag:%s connsess:%s runReceive_recv_message id:%s body:%s qns:%s msgnum:%s\n",
exampid, ltag, conn.Session(),
id, string(md.Message.Body[0:sl]), qns,
md.Message.Headers.Value("msgnum"))
// Handle ACKs if needed
if sngecomm.AckMode() != "auto" {
ah := stompngo.Headers{}
sngecomm.HandleAck(conn, ah, id)
}
if mc == nmsgs {
break
}
if rw {
dt := time.Duration(sngecomm.ValueBetween(min, max, rf))
ll.Printf("%stag:%s connsess:%s recv_stagger dt:%v qns:%s mc:%d\n",
exampid, ltag, conn.Session(),
dt, qns, mc)
tmr.Reset(dt)
_ = <-tmr.C
runtime.Gosched()
}
}
// Unsubscribe
sngecomm.HandleUnsubscribe(conn, d, id)
ll.Printf("%stag:%s connsess:%s runRecieve_ends id:%s qns:%s\n",
exampid, ltag, conn.Session(),
id, qns)
w.Done()
}
// Receive messages from a particular queue
func receiver(conn *stompngo.Connection, qn, nmsgs int) {
ltag := tag + "-receiver"
qns := fmt.Sprintf("%d", qn) // queue number
ll.Printf("%stag:%s connsess:%s starts qns:%d nmsgs:%d\n",
exampid, ltag, conn.Session(),
qn, nmsgs)
//
qp := sngecomm.Dest() // queue name prefix
q := qp + "." + qns
ll.Printf("%stag:%s connsess:%s queue_info q:%s qn:%d nmsgs:%d\n",
exampid, ltag, conn.Session(),
q, qn, nmsgs)
id := stompngo.Uuid() // A unique subscription ID
sc := sngecomm.HandleSubscribe(conn, q, id, sngecomm.AckMode())
ll.Printf("%stag:%s connsess:%s subscribe_complete\n",
exampid, ltag, conn.Session())
// Many receivers running under the same connection can cause
// (wire read) performance issues. This is *very* dependent on the broker
// being used, specifically the broker's algorithm for putting messages on
// the wire.
// To alleviate those issues, this strategy insures that messages are
// received from the wire as soon as possible. Those messages are then
// buffered internally for (possibly later) application processing.
bs := -1 //
if s := os.Getenv("STOMP_CONN2BUFFER"); s != "" {
i, e := strconv.ParseInt(s, 10, 32)
if nil != e {
ll.Fatalf("%stag:%s connsess:%s CONN2BUFFER_conversion_error error:%v",
exampid, ltag, conn.Session(),
e.Error()) // Handle this ......
} else {
bs = int(i)
}
}
if bs < 1 {
bs = nmsgs
}
ll.Printf("%stag:%s connsess:%s mdbuffersize_qnum bs:%d qn:%d\n",
exampid, ltag, conn.Session(),
bs, qn)
// Process all inputs async .......
// var mc chan stompngo.MessageData
mdc := make(chan stompngo.MessageData, bs) // MessageData Buffer size
dc := make(chan bool) // Receive processing done channel
go receiveWorker(mdc, qns, nmsgs, dc, conn, id) // Start async processor
for i := 1; i <= nmsgs; i++ {
mdc <- <-sc // Receive message data as soon as possible, and internally queue it
}
ll.Printf("%stag:%s connsess:%s waitforWorkersBegin qns:%s\n",
exampid, ltag, conn.Session(),
qns)
<-dc // Wait until receive processing is done for this queue
ll.Printf("%stag:%s connsess:%s waitforWorkersEnd qns:%s\n",
exampid, ltag, conn.Session(),
qns)
// Unsubscribe
sngecomm.HandleUnsubscribe(conn, q, id)
ll.Printf("%stag:%s connsess:%s unsubscribe_complete\n",
exampid, ltag, conn.Session())
// Receiving is done
ll.Printf("%stag:%s connsess:%s ends qns:%s\n",
exampid, ltag, conn.Session(),
qns)
wgr.Done()
}
// Asynchronously process all messages for a given subscription.
func receiveWorker(sc <-chan stompngo.MessageData, qns string, nmsgs int,
qc chan<- bool, conn *stompngo.Connection, id string) {
//
ltag := tag + "-receiveWorker"
tmr := time.NewTimer(100 * time.Hour)
pbc := sngecomm.Pbc() // Print byte count
// Receive loop
var md stompngo.MessageData
for i := 1; i <= nmsgs; i++ {
select {
case md = <-sc:
case md = <-conn.MessageData:
// Frames RECEIPT or ERROR not expected here
ll.Fatalf("%stag:%s connsess:%s bad_frame qns:%v md:%v",
exampid, ltag, conn.Session(),
qns, md) // Handle this ......
}
if md.Error != nil {
ll.Fatalf("%stag:%s connsess:%s recv_error qns:%v error:%v",
exampid, ltag, conn.Session(),
qns, md.Error) // Handle this ......
}
// Sanity check the queue and message numbers
mns := fmt.Sprintf("%d", i) // message number
if !md.Message.Headers.ContainsKV("qnum", qns) || !md.Message.Headers.ContainsKV("msgnum", mns) {
ll.Fatalf("%stag:%s connsess:%s dirty_message qnum:%v msgnum:%v md:%v",
exampid, ltag, conn.Session(),
qns, mns, md) // Handle this ......
}
// Process the inbound message .................
sl := len(md.Message.Body)
if pbc > 0 {
sl = pbc
if len(md.Message.Body) < sl {
sl = len(md.Message.Body)
}
}
// Handle ACKs if needed
if sngecomm.AckMode() != "auto" {
ah := []string{}
sngecomm.HandleAck(conn, ah, id)
}
ll.Printf("%stag:%s connsess:%s recv_message body:%s qns:%s msgnum:%s i:%v\n",
exampid, ltag, conn.Session(),
string(md.Message.Body[0:sl]),
qns,
md.Message.Headers.Value("msgnum"), i)
if i == nmsgs {
break
}
if rw {
runtime.Gosched() // yield for this example
dt := time.Duration(sngecomm.ValueBetween(min, max, rf))
ll.Printf("%stag:%s connsess:%s recv_stagger dt:%v qns:%s\n",
exampid, ltag, conn.Session(),
dt, qns)
tmr.Reset(dt)
_ = <-tmr.C
}
}
//
qc <- true
}
func receiveMessages(conn *stompngo.Connection, qnum int, nc net.Conn) {
ltag := tag + "-receivemessages"
qns := fmt.Sprintf("%d", qnum) // queue number
d := sngecomm.Dest() + "." + qns
id := stompngo.Uuid() // A unique subscription ID
ll.Printf("%stag:%s connsess:%s receiveMessages_start id:%s d:%s qnum:%d nmsgs:%d\n",
exampid, ltag, conn.Session(),
id, d, qnum, nmsgs)
// Subscribe
sc := sngecomm.HandleSubscribe(conn, d, id, sngecomm.AckMode())
pbc := sngecomm.Pbc() // Print byte count
//
tmr := time.NewTimer(100 * time.Hour)
var md stompngo.MessageData
for mc := 1; mc <= nmsgs; mc++ {
select {
case md = <-sc:
case md = <-conn.MessageData:
// Frames RECEIPT or ERROR not expected here
ll.Fatalf("%stag:%s connsess:%s send_error qns:%v md:%v",
exampid, ltag, conn.Session(),
qns, md) // Handle this ......
}
if md.Error != nil {
ll.Fatalf("%stag:%s connsess:%s receive_error qns:%v error:%v\n",
exampid, ltag, conn.Session(),
qns, md.Error)
}
if md.Message.Command != stompngo.MESSAGE {
ll.Fatalf("%stag:%s connsess:%s bad_frame qns:%s mc:%d md:%v\n",
exampid, ltag, conn.Session(),
qns, mc, md)
}
mcs := fmt.Sprintf("%d", mc) // message number
if !md.Message.Headers.ContainsKV("qnum", qns) || !md.Message.Headers.ContainsKV("msgnum", mcs) {
ll.Fatalf("%stag:%s connsess:%s dirty_message qns:%v msgnum:%v md:%v",
exampid, tag, conn.Session(),
qns, mcs, md) // Handle this ......
}
// Process the inbound message .................
sl := len(md.Message.Body)
if pbc > 0 {
sl = pbc
if len(md.Message.Body) < sl {
sl = len(md.Message.Body)
}
}
ll.Printf("%stag:%s connsess:%s receiveMessages_msg d:%s body:%s qnum:%d msgnum:%s\n",
exampid, ltag, conn.Session(),
d, string(md.Message.Body[0:sl]), qnum,
md.Message.Headers.Value("msgnum"))
if mc == nmsgs {
break
}
// Handle ACKs if needed
if sngecomm.AckMode() != "auto" {
ah := []string{}
sngecomm.HandleAck(conn, ah, id)
}
if mc == nmsgs {
break
}
//
if rw {
runtime.Gosched() // yield for this example
dt := time.Duration(sngecomm.ValueBetween(min, max, rf))
ll.Printf("%stag:%s connsess:%s recv_stagger dt:%v qns:%s mc:%d\n",
exampid, ltag, conn.Session(),
dt, qns, mc)
tmr.Reset(dt)
_ = <-tmr.C
}
}
ll.Printf("%stag:%s connsess:%s end d:%s qnum:%d nmsgs:%d\n",
exampid, ltag, conn.Session(),
d, qnum, nmsgs)
// Unsubscribe
sngecomm.HandleUnsubscribe(conn, d, id)
//
}