micro/broker/nats_broker.go
2015-05-23 13:13:55 +01:00

105 lines
1.8 KiB
Go

package broker
import (
"encoding/json"
"strings"
"time"
"code.google.com/p/go-uuid/uuid"
"github.com/apcera/nats"
)
type NatsBroker struct {
addrs []string
conn *nats.Conn
}
type NatsSubscriber struct {
s *nats.Subscription
}
func (n *NatsSubscriber) Topic() string {
return n.s.Subject
}
func (n *NatsSubscriber) Unsubscribe() error {
return n.s.Unsubscribe()
}
func (n *NatsBroker) Address() string {
if len(n.addrs) > 0 {
return n.addrs[0]
}
return ""
}
func (n *NatsBroker) Connect() error {
if n.conn != nil {
return nil
}
opts := nats.DefaultOptions
opts.Servers = n.addrs
c, err := opts.Connect()
if err != nil {
return err
}
n.conn = c
return nil
}
func (n *NatsBroker) Disconnect() error {
n.conn.Close()
return nil
}
func (n *NatsBroker) Init() error {
return nil
}
func (n *NatsBroker) Publish(topic string, data []byte) error {
b, err := json.Marshal(&Message{
Id: uuid.NewUUID().String(),
Timestamp: time.Now().Unix(),
Topic: topic,
Data: data,
})
if err != nil {
return err
}
return n.conn.Publish(topic, b)
}
func (n *NatsBroker) Subscribe(topic string, function func(*Message)) (Subscriber, error) {
subscriber, err := n.conn.Subscribe(topic, func(msg *nats.Msg) {
var data *Message
if err := json.Unmarshal(msg.Data, &data); err != nil {
return
}
function(data)
})
if err != nil {
return nil, err
}
return &NatsSubscriber{s: subscriber}, nil
}
func NewNatsBroker(addrs []string, opts ...Options) Broker {
var cAddrs []string
for _, addr := range addrs {
if len(addr) == 0 {
continue
}
if !strings.HasPrefix(addr, "nats://") {
addr = "nats://" + addr
}
cAddrs = append(cAddrs, addr)
}
if len(cAddrs) == 0 {
cAddrs = []string{nats.DefaultURL}
}
return &NatsBroker{
addrs: cAddrs,
}
}