func WatchLocalChanges() {
channel := q.MustChan()
go declareExchange(channel)
watcher, err := fsnotify.NewWatcher()
if err != nil {
log.Fatal(err)
}
// Process events
go func() {
for {
select {
case ev := <-watcher.Event:
// log.Println("event:", ev)
if !ev.IsAttrib() {
handleChange(channel, ev)
}
case err := <-watcher.Error:
log.Println("PUBLISHER: error:", err)
}
}
watcher.Close()
}()
err = watcher.Watch(rootDir)
if err != nil {
log.Fatal(err)
}
}
func ListenForChanges() {
var err error
hostname, _ = os.Hostname()
channel := q.MustChan()
log.Println("CONSUMER: got Channel, declaring Exchange")
if err = channel.ExchangeDeclare(
"changes", // name of the exchange
"fanout", // type
true, // durable
true, // delete when complete
false, // internal
false, // noWait
nil, // arguments
); err != nil {
panic(fmt.Errorf("Exchange Declare: %s", err))
}
log.Printf("CONSUMER: declaring Queue (%s)", hostname)
state, err := channel.QueueDeclare(
hostname, // name of the queue
true, // durable
false, // delete when usused
false, // exclusive
false, // noWait
amqp.Table{}, // arguments
)
if err != nil {
panic(fmt.Errorf("Queue Declare: %s", err))
}
log.Printf("CONSUMER: binding to Exchange (key '%s')", state.Messages, state.Consumers, "")
if err = channel.QueueBind(
hostname, // name of the queue
"", // bindingKey
"changes", // sourceExchange
false, // noWait
nil, // arguments
); err != nil {
panic(fmt.Errorf("Queue Bind: %s", err))
}
log.Printf("CONSUMER: Queue bound to Exchange, starting Consume")
changes, err := channel.Consume(
hostname, // name
"", // consumerTag,
false, // auto-ack
false, // exclusive
false, // noLocal
false, // noWait
nil, // arguments
)
if err != nil {
panic(fmt.Errorf("Queue Consume: %s", err))
}
go handle(changes)
}
func RequestFile(change *Change) {
log.Println("requesting file", change.Path)
var err error
channel := q.MustChan()
queue, err := channel.QueueDeclare(
"", // name of the queue
false, // durable
true, // delete when usused
true, // exclusive
false, // noWait
nil, // arguments
)
if err != nil {
panic(fmt.Errorf("Queue Declare: %s", err))
}
t := &Transfer{
Checksum: change.Checksum,
Path: change.Path,
Requestor: hostname,
}
req, _ := json.Marshal(t)
err = channel.Publish(
"file-requests", // exchange
"", // routing key
false, // mandatory
false, // immediate
amqp.Publishing{
ContentType: "application/json",
Body: req,
ReplyTo: queue.Name,
})
go WaitForFile(channel, change.Path, queue.Name)
}
func ListenForTransferRequests() {
channel := q.MustChan()
if err := channel.ExchangeDeclare(
"file-requests", // name of the exchange
"fanout", // type
true, // durable
false, // delete when complete
false, // internal
false, // noWait
nil, // arguments
); err != nil {
panic(fmt.Errorf("Exchange Declare: %s", err))
}
queue, err := channel.QueueDeclare(
fmt.Sprintf("%s-files", hostname), // name of the queue
false, // durable
true, // delete when usused
true, // exclusive
false, // noWait
nil, // arguments
)
if err != nil {
panic(fmt.Errorf("Failed to declare a queue %s", err.Error()))
}
if err = channel.QueueBind(
queue.Name, // name of the queue
"", // bindingKey
"file-requests", // sourceExchange
false, // noWait
nil, // arguments
); err != nil {
panic(fmt.Errorf("Queue Bind: %s", err))
}
err = channel.Qos(
1, // prefetch count
0, // prefetch size
false, // global
)
if err != nil {
panic(fmt.Errorf("Failed to set QoS %s", err.Error()))
}
msgs, err := channel.Consume(
queue.Name, // queue
"", // consumer
false, // auto-ack
false, // exclusive
false, // no-local
false, // no-wait
nil, // args
)
if err != nil {
panic(fmt.Errorf("Failed to register a consumer %s", err.Error()))
}
log.Println("awaiting file transfer requests...")
for msg := range msgs {
msg.Ack(false)
var transfer Transfer
if err := json.Unmarshal(msg.Body, &transfer); err != nil {
log.Println(fmt.Errorf("received a dirty transfer request '%s' %s", string(msg.Body), err.Error()))
msg.Reject(false)
continue
}
if transfer.Requestor == hostname {
continue
}
log.Println("received a file transfer request", transfer.Path)
go HandleTransfer(transfer, &msg)
}
log.Println("no longer consuming transfers")
}