/
receivers.go
73 lines (65 loc) · 1.4 KB
/
receivers.go
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package main
import (
"net"
"net/url"
"strings"
"sync"
log "github.com/Sirupsen/logrus"
)
type receiver interface {
// Close connection and channels
Close()
// Run a goroutine and pass read messages to channel
Receive() <-chan string
// Listen for incoming packets
Listen() error
}
type UDPreceiver struct {
conn *net.UDPConn
url *url.URL
wg *sync.WaitGroup
}
func (rec *UDPreceiver) Close() {
if rec.conn != nil {
rec.conn.Close()
rec.wg.Wait()
}
}
func (rec *UDPreceiver) Listen() error {
addr, err := net.ResolveUDPAddr("udp", rec.url.Host)
if err != nil {
return err
}
conn, err := net.ListenUDP("udp", addr)
rec.conn = conn
return err
}
func (rec *UDPreceiver) Receive() <-chan string {
out := make(chan string, maxBatchEvents)
rec.wg.Add(1)
go func() {
var buf [maxEventSize]byte
defer rec.wg.Done()
defer close(out)
for {
n, err := rec.conn.Read(buf[0:])
// For more info why string comparison see https://github.com/golang/go/issues/4373
if err != nil && strings.Contains(err.Error(), "use of closed network connection") {
return
} else if err != nil {
log.Fatal(err)
}
out <- string(buf[0:n])
}
}()
return out
}
// Create a new receiver based on passed address.
func newReceiver(address string) receiver {
url, _ := url.Parse(address)
switch url.Scheme {
case "udp":
return &UDPreceiver{url: url, wg: &sync.WaitGroup{}}
}
return nil
}