/
nats.go
59 lines (49 loc) · 1019 Bytes
/
nats.go
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package heartbeat
import (
"context"
"encoding/json"
"sync/atomic"
"github.com/altairsix/pkg/action"
"github.com/nats-io/go-nats"
)
type natsHeartbeat struct {
nc *nats.Conn
subject string
}
func (n *natsHeartbeat) Publish(tick action.Tick) error {
data, err := json.Marshal(tick)
if err != nil {
return err
}
return n.nc.Publish(n.subject, data)
}
func (n *natsHeartbeat) Receive(ctx context.Context) (<-chan action.Tick, error) {
ch := make(chan action.Tick, 16)
open := int32(1)
sub, err := n.nc.Subscribe(n.subject, func(msg *nats.Msg) {
tick := action.Tick{}
if err := json.Unmarshal(msg.Data, &tick); err == nil {
if atomic.LoadInt32(&open) == 1 {
ch <- tick
}
}
})
if err != nil {
return nil, err
}
go func() {
select {
case <-ctx.Done():
atomic.StoreInt32(&open, 1)
close(ch)
sub.Unsubscribe()
}
}()
return ch, nil
}
func Nats(nc *nats.Conn, subject string) action.Heartbeat {
return &natsHeartbeat{
nc: nc,
subject: subject,
}
}