123 lines
2.2 KiB
Go
123 lines
2.2 KiB
Go
package nats
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import (
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"encoding/json"
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"strings"
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"time"
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"code.google.com/p/go-uuid/uuid"
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"github.com/apcera/nats"
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"github.com/myodc/go-micro/broker"
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c "github.com/myodc/go-micro/context"
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"golang.org/x/net/context"
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)
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type nbroker struct {
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addrs []string
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conn *nats.Conn
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}
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type subscriber struct {
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s *nats.Subscription
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}
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// used in brokers where there is no support for headers
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type envelope struct {
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Header map[string]string
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Message *broker.Message
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}
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func (n *subscriber) Topic() string {
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return n.s.Subject
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}
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func (n *subscriber) Unsubscribe() error {
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return n.s.Unsubscribe()
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}
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func (n *nbroker) Address() string {
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if len(n.addrs) > 0 {
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return n.addrs[0]
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}
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return ""
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}
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func (n *nbroker) Connect() error {
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if n.conn != nil {
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return nil
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}
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opts := nats.DefaultOptions
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opts.Servers = n.addrs
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c, err := opts.Connect()
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if err != nil {
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return err
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}
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n.conn = c
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return nil
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}
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func (n *nbroker) Disconnect() error {
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n.conn.Close()
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return nil
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}
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func (n *nbroker) Init() error {
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return nil
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}
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func (n *nbroker) Publish(ctx context.Context, topic string, body []byte) error {
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header, _ := c.GetMetaData(ctx)
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message := &broker.Message{
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Id: uuid.NewUUID().String(),
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Timestamp: time.Now().Unix(),
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Topic: topic,
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Body: body,
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}
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b, err := json.Marshal(&envelope{
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header,
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message,
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})
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if err != nil {
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return err
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}
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return n.conn.Publish(topic, b)
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}
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func (n *nbroker) Subscribe(topic string, function func(context.Context, *broker.Message)) (broker.Subscriber, error) {
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sub, err := n.conn.Subscribe(topic, func(msg *nats.Msg) {
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var e *envelope
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if err := json.Unmarshal(msg.Data, &e); err != nil {
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return
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}
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ctx := c.WithMetaData(context.Background(), e.Header)
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function(ctx, e.Message)
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})
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if err != nil {
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return nil, err
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}
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return &subscriber{s: sub}, nil
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}
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func NewBroker(addrs []string, opt ...broker.Option) broker.Broker {
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var cAddrs []string
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for _, addr := range addrs {
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if len(addr) == 0 {
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continue
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}
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if !strings.HasPrefix(addr, "nats://") {
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addr = "nats://" + addr
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}
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cAddrs = append(cAddrs, addr)
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}
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if len(cAddrs) == 0 {
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cAddrs = []string{nats.DefaultURL}
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}
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return &nbroker{
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addrs: cAddrs,
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}
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}
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