// Connect to a STOMP broker, publish some messages and disconnect.
func main() {
st := time.Now()
// Standard example connect sequence
n, conn, e := sngecomm.CommonConnect(exampid, tag, ll)
if e != nil {
ll.Fatalf("%stag:%s connsess:%s main_on_connect error:%v",
exampid, tag, sngecomm.Lcs,
e.Error()) // Handle this ......
}
// *NOTE* application specific functionaltiy starts here!
sh := stompngo.Headers{"destination", sngecomm.Dest()}
ll.Printf("%stag:%s connsess:%s destination dest:%s\n",
exampid, tag, conn.Session(),
sngecomm.Dest())
if senv.Persistent() {
sh = sh.Add("persistent", "true")
}
ms := exampid + "message: "
for i := 1; i <= senv.Nmsgs(); i++ {
mse := ms + fmt.Sprintf("%d", i)
ll.Printf("%stag:%s connsess:%s main_sending mse:~%s~\n",
exampid, tag, conn.Session(),
mse)
e := conn.Send(sh, mse)
if e != nil {
ll.Fatalf("%stag:%s connsess:%s main_on_connect error:%v",
exampid, tag, conn.Session(),
e.Error()) // Handle this ......
}
ll.Printf("%stag:%s connsess:%s main_send_complete mse:~%s~\n",
exampid, tag, conn.Session(),
mse)
time.Sleep(100 * time.Millisecond)
}
// *NOTE* application specific functionaltiy ends here!
// Standard example disconnect sequence
e = sngecomm.CommonDisconnect(n, conn, exampid, tag, ll)
if e != nil {
ll.Fatalf("%stag:%s connsess:%s main_on_disconnect error:%v",
exampid, tag, conn.Session(),
e.Error()) // Handle this ......
}
ll.Printf("%stag:%s connsess:%s main_elapsed:%v\n",
exampid, tag, conn.Session(),
time.Now().Sub(st))
}
// Send messages to a particular queue
func sender(qn, mc int) {
ltag := tag + "-sender"
qns := fmt.Sprintf("%d", qn) // string queue number
id := stompngo.Uuid() // A unique sender id
d := sngecomm.Dest() + "." + qns
ll.Printf("%stag:%s connsess:%s queue_info id:%v d:%v qnum:%v mc:%v\n",
exampid, ltag, conn.Session(),
id, d, qn, mc)
//
wh := stompngo.Headers{"destination", d, "senderId", id,
"qnum", qns} // send Headers
if senv.Persistent() {
wh = wh.Add("persistent", "true")
}
//
tmr := time.NewTimer(100 * time.Hour)
// Send loop
for i := 1; i <= mc; i++ {
si := fmt.Sprintf("%d", i)
sh := append(wh, "msgnum", si)
// Generate a message to send ...............
ll.Printf("%stag:%s connsess:%s send_headers id:%v d:%v qnum:%v headers:%v\n",
exampid, ltag, conn.Session(),
id, d, qn, sh)
e := conn.Send(sh, string(sngecomm.Partial()))
if e != nil {
ll.Fatalf("%stag:%s connsess:%s send_error qnum:%v error:%v",
exampid, tag, conn.Session(),
qn, e.Error()) // Handle this ......
}
if i == mc {
break
}
if sw {
dt := time.Duration(sngecomm.ValueBetween(min, max, sf))
ll.Printf("%stag:%s connsess:%s send_stagger id:%v d:%v qnum:%v stagger:%v\n",
exampid, ltag, conn.Session(),
id, d, qn, dt)
tmr.Reset(dt)
_ = <-tmr.C
runtime.Gosched()
}
}
// Sending is done
ll.Printf("%stag:%s connsess:%s finish_info id:%v d:%v qnum:%v mc:%v\n",
exampid, ltag, conn.Session(),
id, d, qn, mc)
wgs.Done()
}
// 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()
}
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()
}
// A forever reader.
func main() {
st := time.Now()
sngecomm.ShowRunParms(exampid)
// Standard example connect sequence
var e error
n, conn, e = sngecomm.CommonConnect(exampid, tag, ll)
if e != nil {
if conn != nil {
ll.Printf("%stag:%s connsess:%s Connect Response headers:%v body%s\n",
exampid, tag, conn.Session(), conn.ConnectResponse.Headers,
string(conn.ConnectResponse.Body))
}
ll.Fatalf("%stag:%s connsess:%s main_on_connect error:%v",
exampid, tag, sngecomm.Lcs,
e.Error()) // Handle this ......
}
//**
qn := 1
ltag := tag + "-receiver"
id := stompngo.Uuid() // A unique subscription ID
d := sngecomm.Dest()
ll.Printf("%stag:%s connsess:%s queue_info id:%v d:%v qnum:%v\n",
exampid, ltag, conn.Session(),
id, d, qn)
// Subscribe
sc := sngecomm.HandleSubscribe(conn, d, id, sngecomm.AckMode())
ll.Printf("%stag:%s connsess:%s subscribe_complete id:%v d:%v qnum:%v\n",
exampid, ltag, conn.Session(),
id, d, qn)
//
var md stompngo.MessageData
// Receive loop
mc := 1
for {
ll.Println("========================== ", "Expecting Message:", mc,
"==========================")
select {
case md = <-sc:
case md = <-conn.MessageData:
// A RECEIPT or ERROR frame is unexpected here
ll.Fatalf("%stag:%s connsess:%s bad_frame qnum:%v headers:%v body:%s",
exampid, tag, conn.Session(),
qn, md.Message.Headers, md.Message.Body) // Handle this ......
}
if md.Error != nil {
ll.Fatalf("%stag:%s connsess:%s recv_error qnum:%v error:%v",
exampid, tag, conn.Session(),
qn, md.Error) // Handle this ......
}
ll.Printf("%stag:%s connsess:%s next_frame mc:%v command:%v headers:%v body:%v\n",
exampid, tag, conn.Session(),
mc, md.Message.Command, md.Message.Headers, string(md.Message.Body)) // Handle this ......
mc++
}
//**
// Standard example disconnect sequence
e = sngecomm.CommonDisconnect(n, conn, exampid, tag, ll)
if e != nil {
ll.Fatalf("%stag:%s connsess:%s main_on_disconnect error:%v",
exampid, tag, conn.Session(),
e.Error()) // Handle this ......
}
sngecomm.ShowStats(exampid, tag, conn)
ll.Printf("%stag:%s connsess:%s main_elapsed:%v\n",
exampid, tag, conn.Session(),
time.Now().Sub(st))
}
// 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()
}
func main() {
// Make sure that the queue used by this example do not exist, or are
// empty.
// Following is a lengthy piece of code. Read it striaght from top
// to bottom. There is zero complex logic here.
// What this code will do:
// Phase 1:
// - Connect to a broker
// - Verify a connection spec level
// - Send a single message to the specified queue on that broker
// - Disconnect from that broker
//
// Phase 2:
// - Reconnect to the same broker
// - Subscribe to the specified queue, using "ack:client-individual"
// - Receive a single message
// - Send an ACK, asking for a receipt
//**************************************************************************
// - Receive a RECEIPT // The point of this exercise.
// - Show data from the RECEIPT and verify it // The point of this exercise.
//**************************************************************************
// - Disconnect from the broker
// Start
st := time.Now()
// **************************************** Phase 1
// Set up the connection.
// Standard example connect sequence
n, conn, e := sngecomm.CommonConnect(exampid, tag, ll)
if e != nil {
ll.Fatalf("%stag:%s connsess:%s main_on_connect error:%v",
exampid, tag, sngecomm.Lcs,
e.Error()) // Handle this ......
}
// ****************************************
// App logic here .....
d := sngecomm.Dest()
ll.Printf("%stag:%s connsess:%s destination:%v\n",
exampid, tag, conn.Session(),
d)
// ****************************************
// Send exactly one message.
sh := stompngo.Headers{"destination", sngecomm.Dest()}
if senv.Persistent() {
sh = sh.Add("persistent", "true")
}
m := exampid + " message: "
t := m + "1"
ll.Printf("%stag:%s connsess:%s sending_now body:%v\n",
exampid, tag, conn.Session(),
t)
e = conn.Send(sh, t)
if e != nil {
ll.Fatalf("%stag:%s connsess:%s main_bad_send error:%v",
exampid, tag, conn.Session(),
e.Error()) // Handle this ......
}
ll.Printf("%stag:%s connsess:%s send_complete body:%v\n",
exampid, tag, conn.Session(),
t)
// ****************************************
// Disconnect from the Stomp server
// Standard example disconnect sequence
e = sngecomm.CommonDisconnect(n, conn, exampid, tag, ll)
if e != nil {
ll.Fatalf("%stag:%s connsess:%s main_disconnect error:%v",
exampid, tag, conn.Session(),
e.Error()) // Handle this ......
}
// **************************************** Phase 2
// Standard example connect sequence
n, conn, e = sngecomm.CommonConnect(exampid, tag, ll)
if e != nil {
ll.Fatalf("%stag:%s connsess:%s main_on_connect error:%v",
exampid, tag, sngecomm.Lcs,
e.Error()) // Handle this ......
}
// ****************************************
// Subscribe here
id := stompngo.Uuid()
// Get the "subscribe channel"
sc := sngecomm.HandleSubscribe(conn, d, id, "client-individual")
ll.Printf("%stag:%s connsess:%s stomp_subscribe_complete\n",
exampid, tag, conn.Session())
// Get data from the broker
var md stompngo.MessageData // A message data instance
select {
case md = <-sc:
case md = <-conn.MessageData:
// This would be contain an ERROR or RECEIPT frame. Both are unexpected
// in this example.
ll.Fatalf("%stag:%s connsess:%s bad_frame md:%v",
exampid, tag, conn.Session(),
md) // Handle this ......
}
ll.Printf("%stag:%s connsess:%s channel_read_complete\n",
exampid, tag, conn.Session())
// MessageData has two components:
// a) a Message struct
// b) an Error value. Check the error value as usual
if md.Error != nil {
ll.Fatalf("%stag:%s connsess:%s message_error md:%v",
exampid, tag, conn.Session(),
md.Error) // Handle this ......
}
ll.Printf("%stag:%s connsess:%s read_message_COMMAND command:%s\n",
exampid, tag, conn.Session(),
md.Message.Command)
ll.Printf("%stag:%s connsess:%s read_message_HEADERS headers:%s\n",
exampid, tag, conn.Session(),
md.Message.Headers)
ll.Printf("%stag:%s connsess:%s read_message_BODY body:%s\n",
exampid, tag, conn.Session(),
string(md.Message.Body))
// Here we need to send an ACK. Required Headers are different between
// a 1.1 and a 1.2 connection level.
var ah stompngo.Headers
if conn.Protocol() == stompngo.SPL_11 { // 1.1
ah = ah.Add("subscription", md.Message.Headers.Value("subscription"))
ah = ah.Add("message-id", md.Message.Headers.Value("message-id"))
} else { // 1.2
ah = ah.Add("id", md.Message.Headers.Value("ack"))
}
// We are also going to ask for a RECEIPT for the ACK
rid := "receipt-001"
ah = ah.Add("receipt", rid)
//
ll.Printf("%stag:%s connsess:%s ACK_receipt_headers headers:%v\n",
exampid, tag, conn.Session(),
ah)
e = conn.Ack(ah)
if e != nil {
ll.Fatalf("%stag:%s connsess:%s ack_error error:%v",
exampid, tag, conn.Session(),
e.Error()) // Handle this ......
}
// ****************************************
// Finally get the RECEIPT. Where is it? It is *not* on the "subscribe
// channel". It is on the connection level MessageData channel. Why?
// Because the broker does *not* include a "subscription" header in
// RECEIPT frames..
// ****************************************
// ***IMPORTANT***
// ***NOTE*** which channel this RECEIPT MessageData comes in on.
ll.Printf("%stag:%s connsess:%s start_receipt_read\n",
exampid, tag, conn.Session())
var rd stompngo.MessageData
select {
case rd = <-sc:
// This would contain a MESSAGE frame. It is unexpected here
// in this example.
ll.Fatalf("%stag:%s connsess:%s bad_frame_channel rd:%v\n",
exampid, tag, conn.Session(),
rd) // Handle this ......
case rd = <-conn.MessageData: // RECEIPT frame s/b in the MessageData
// Step 1 of Verify
if rd.Message.Command != stompngo.RECEIPT {
ll.Fatalf("%stag:%s connsess:%s bad_frame_command rd:%v\n",
exampid, tag, conn.Session(),
rd) // Handle this ......
}
}
ll.Printf("%stag:%s connsess:%s end_receipt_read\n",
exampid, tag, conn.Session())
// ****************************************
// Show details about the RECEIPT MessageData struct
ll.Printf("%stag:%s connsess:%s receipt_COMMAND command:%s\n",
exampid, tag, conn.Session(),
rd.Message.Command)
ll.Printf("%stag:%s connsess:%s receipt_HEADERS headers:%v\n",
exampid, tag, conn.Session(),
rd.Message.Headers)
ll.Printf("%stag:%s connsess:%s receipt_BODY body:%s\n",
exampid, tag, conn.Session(),
string(rd.Message.Body))
// Step 2 of Verify
// Verify that the receipt has the id we asked for
if rd.Message.Headers.Value("receipt-id") != rid {
ll.Fatalf("%stag:%s connsess:%s bad_receipt_id wanted:%v got:%v\n",
exampid, tag, conn.Session(),
rid, rd.Message.Headers.Value("receipt-id")) // Handle this ......
}
ll.Printf("%stag:%s connsess:%s receipt_id_verified rid:%s\n",
exampid, tag, conn.Session(),
rid)
// ****************************************
// Disconnect from the Stomp server
// Standard example disconnect sequence
e = sngecomm.CommonDisconnect(n, conn, exampid, tag, ll)
if e != nil {
ll.Fatalf("%stag:%s connsess:%s main_disconnect error:%v",
exampid, tag, sngecomm.Lcs,
e.Error()) // Handle this ......
}
ll.Printf("%stag:%s connsess:%s main_elapsed:%v\n",
exampid, tag, conn.Session(),
time.Now().Sub(st))
}
func main() {
st := time.Now()
// ****************************************
// Set up the connection.
// Standard example connect sequence
n, conn, e := sngecomm.CommonConnect(exampid, tag, ll)
if e != nil {
ll.Fatalf("%stag:%s connsess:%s main_on_connect error:%v",
exampid, tag, sngecomm.Lcs,
e.Error()) // Handle this ......
}
// ****************************************
// App logic here .....
// Send exactly one message. Ask for a receipt.
d := sngecomm.Dest()
ll.Printf("%stag:%s connsess:%s destination:%v\n",
exampid, tag, conn.Session(),
d)
rid := "recipt-002" // The receipt ID
sh := stompngo.Headers{"destination", d,
"receipt", rid} // send headers
if senv.Persistent() {
sh = sh.Add("persistent", "true")
}
ms := exampid + " message: "
t := ms + rid
ll.Printf("%stag:%s connsess:%s sending_now body:%v\n",
exampid, tag, conn.Session(),
t)
e = conn.Send(sh, t)
if e != nil {
ll.Fatalf("%stag:%s connsess:%s main_bad_send error:%v",
exampid, tag, conn.Session(),
e.Error()) // Handle this ......
}
ll.Printf("%stag:%s connsess:%s send_complete body:%v\n",
exampid, tag, conn.Session(),
t)
// Look for the receipt
ll.Printf("%stag:%s connsess:%s start_receipt_read\n",
exampid, tag, conn.Session())
rd := <-conn.MessageData // The RECEIPT frame should be on this channel
if rd.Message.Command != stompngo.RECEIPT {
ll.Fatalf("%stag:%s connsess:%s bad_frame_command rd:%v\n",
exampid, tag, conn.Session(),
rd) // Handle this ......
}
ll.Printf("%stag:%s connsess:%s end_receipt_read\n",
exampid, tag, conn.Session())
// ****************************************
// Show details about the RECEIPT MessageData struct
ll.Printf("%stag:%s connsess:%s receipt_COMMAND command:%s\n",
exampid, tag, conn.Session(),
rd.Message.Command)
ll.Printf("%stag:%s connsess:%s receipt_HEADERS headers:%v\n",
exampid, tag, conn.Session(),
rd.Message.Headers)
ll.Printf("%stag:%s connsess:%s receipt_BODY body:%s\n",
exampid, tag, conn.Session(),
string(rd.Message.Body))
// Step 2 of Verify
// Verify that the receipt has the id we asked for
if rd.Message.Headers.Value("receipt-id") != rid {
ll.Fatalf("%stag:%s connsess:%s bad_receipt_id wanted:%v got:%v\n",
exampid, tag, conn.Session(),
rid, rd.Message.Headers.Value("receipt-id")) // Handle this ......
}
ll.Printf("%stag:%s connsess:%s receipt_id_verified rid:%s\n",
exampid, tag, conn.Session(),
rid)
e = sngecomm.CommonDisconnect(n, conn, exampid, tag, ll)
if e != nil {
ll.Fatalf("%stag:%s connsess:%s main_disconnect error:%v",
exampid, tag, sngecomm.Lcs,
e.Error()) // Handle this ......
}
ll.Printf("%stag:%s connsess:%s main_elapsed:%v\n",
exampid, tag, conn.Session(),
time.Now().Sub(st))
}
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)
//
}
// Receive messages from a particular queue
func receiver(qn, mc int) {
ltag := tag + "-receiver"
qns := fmt.Sprintf("%d", qn) // string queue number
pbc := sngecomm.Pbc()
id := stompngo.Uuid() // A unique subscription ID
d := sngecomm.Dest() + "." + qns
ll.Printf("%stag:%s connsess:%s queue_info id:%v d:%v qnum:%v mc:%v\n",
exampid, ltag, conn.Session(),
id, d, qn, mc)
// Subscribe
sc := sngecomm.HandleSubscribe(conn, d, id, sngecomm.AckMode())
ll.Printf("%stag:%s connsess:%s subscribe_complete id:%v d:%v qnum:%v mc:%v\n",
exampid, ltag, conn.Session(),
id, d, qn, mc)
//
tmr := time.NewTimer(100 * time.Hour)
var md stompngo.MessageData
// Receive loop
for i := 1; i <= mc; i++ {
ll.Printf("%stag:%s connsess:%s recv_ranchek id:%v d:%v qnum:%v mc:%v chlen:%v chcap:%v\n",
exampid, ltag, conn.Session(),
id, d, qn, mc, len(sc), cap(sc))
select {
case md = <-sc:
case md = <-conn.MessageData:
// A RECEIPT or ERROR frame is unexpected here
ll.Fatalf("%stag:%s connsess:%s bad_frame qnum:%v headers:%v body:%s",
exampid, tag, conn.Session(),
qn, md.Message.Headers, md.Message.Body) // Handle this ......
}
if md.Error != nil {
ll.Fatalf("%stag:%s connsess:%s recv_error qnum:%v error:%v",
exampid, tag, conn.Session(),
qn, md.Error) // Handle this ......
}
// Process the inbound message .................
ll.Printf("%stag:%s connsess:%s recv_message qnum:%v i:%v\n",
exampid, tag, conn.Session(),
qn, i)
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 qnum:%v body:%s\n",
exampid, tag, conn.Session(),
qn, ss)
}
// Sanity check the message Command, and the queue and message numbers
mns := fmt.Sprintf("%d", i) // message number
if md.Message.Command != stompngo.MESSAGE {
ll.Fatalf("%stag:%s connsess:%s bad_frame qnum:%v command:%v headers:%v body:%v\n",
exampid, tag, conn.Session(),
qn, md.Message.Command, md.Message.Headers, string(md.Message.Body)) // Handle this ......
}
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 command:%v headers:%v body:%v\n",
exampid, tag, conn.Session(),
qns, mns, md.Message.Command, md.Message.Headers, string(md.Message.Body)) // Handle this ......) // Handle this ......
}
if i == mc {
break
}
if rw {
dt := time.Duration(sngecomm.ValueBetween(min, max, rf))
ll.Printf("%stag:%s connsess:%s recv_stagger id:%v d:%v qnum:%v stagger:%v\n",
exampid, ltag, conn.Session(),
id, d, qn, dt)
tmr.Reset(dt)
_ = <-tmr.C
runtime.Gosched()
}
// Handle ACKs if needed
if sngecomm.AckMode() != "auto" {
sngecomm.HandleAck(conn, md.Message.Headers, id)
}
}
// Unsubscribe
sngecomm.HandleUnsubscribe(conn, d, id)
ll.Printf("%stag:%s connsess:%s unsubscribe_complete id:%v d:%v qnum:%v mc:%v\n",
exampid, ltag, conn.Session(),
id, d, qn, mc)
// Receiving is done
ll.Printf("%stag:%s connsess:%s recv_end id:%v d:%v qnum:%v mc:%v\n",
exampid, ltag, conn.Session(),
id, d, qn, mc)
wgr.Done()
}