micro-broker-nats/nats.go
2021-01-29 18:14:34 +03:00

108 lines
1.8 KiB
Go

package nats
import (
"encoding/json"
"strings"
"github.com/apcera/nats"
"github.com/micro/go-micro/broker"
"github.com/micro/go-micro/cmd"
)
type nbroker struct {
addrs []string
conn *nats.Conn
}
type subscriber struct {
s *nats.Subscription
}
func init() {
cmd.Brokers["nats"] = NewBroker
}
func (n *subscriber) Topic() string {
return n.s.Subject
}
func (n *subscriber) Unsubscribe() error {
return n.s.Unsubscribe()
}
func (n *nbroker) Address() string {
if len(n.addrs) > 0 {
return n.addrs[0]
}
return ""
}
func (n *nbroker) 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 *nbroker) Disconnect() error {
n.conn.Close()
return nil
}
func (n *nbroker) Init() error {
return nil
}
func (n *nbroker) Publish(topic string, msg *broker.Message) error {
b, err := json.Marshal(msg)
if err != nil {
return err
}
return n.conn.Publish(topic, b)
}
func (n *nbroker) Subscribe(topic string, handler broker.Handler) (broker.Subscriber, error) {
sub, err := n.conn.Subscribe(topic, func(msg *nats.Msg) {
var m *broker.Message
if err := json.Unmarshal(msg.Data, &m); err != nil {
return
}
handler(m)
})
if err != nil {
return nil, err
}
return &subscriber{s: sub}, nil
}
func (n *nbroker) String() string {
return "nats"
}
func NewBroker(addrs []string, opt ...broker.Option) broker.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 &nbroker{
addrs: cAddrs,
}
}