add proper pubsub

lib/service/pubsub.go

@@ -0,0 +1,48 @@
+package service
+
+import (
+	"sync"
+
+	"github.com/getAlby/lndhub.go/db/models"
+)
+
+type Pubsub struct {
+	mu   sync.RWMutex
+	subs map[int64]map[string]chan models.Invoice
+}
+
+func NewPubsub() *Pubsub {
+	ps := &Pubsub{}
+	ps.subs = make(map[int64]map[string]chan models.Invoice)
+	return ps
+}
+
+func (ps *Pubsub) Subscribe(id string, topic int64, ch chan models.Invoice) {
+	ps.mu.Lock()
+	defer ps.mu.Unlock()
+
+	ps.subs[topic][id] = ch
+}
+
+func (ps *Pubsub) Unsubscribe(id string, topic int64) {
+	ps.mu.Lock()
+	defer ps.mu.Unlock()
+	delete(ps.subs[topic], id)
+}
+
+func (ps *Pubsub) Publish(topic int64, msg models.Invoice) {
+	ps.mu.RLock()
+	defer ps.mu.RUnlock()
+
+	for _, ch := range ps.subs[topic] {
+		ch <- msg
+	}
+}
+
+func (ps *Pubsub) CloseAll() {
+	for _, subs := range ps.subs {
+		for _, ch := range subs {
+			close(ch)
+		}
+	}
+}