Files
zitadel/apps/api/internal/eventstore/subscription.go
2025-08-05 15:20:32 -07:00

107 lines
2.2 KiB
Go

package eventstore
import (
"slices"
"sync"
"github.com/zitadel/logging"
)
var (
subscriptions = map[AggregateType][]*Subscription{}
subsMutex sync.RWMutex
)
type Subscription struct {
Events chan Event
types map[AggregateType][]EventType
}
// SubscribeAggregates subscribes for all events on the given aggregates
func SubscribeAggregates(eventQueue chan Event, aggregates ...AggregateType) *Subscription {
types := make(map[AggregateType][]EventType, len(aggregates))
for _, aggregate := range aggregates {
types[aggregate] = nil
}
sub := &Subscription{
Events: eventQueue,
types: types,
}
subsMutex.Lock()
defer subsMutex.Unlock()
for _, aggregate := range aggregates {
subscriptions[aggregate] = append(subscriptions[aggregate], sub)
}
return sub
}
// SubscribeEventTypes subscribes for the given event types
// if no event types are provided the subscription is for all events of the aggregate
func SubscribeEventTypes(eventQueue chan Event, types map[AggregateType][]EventType) *Subscription {
sub := &Subscription{
Events: eventQueue,
types: types,
}
subsMutex.Lock()
defer subsMutex.Unlock()
for aggregate := range types {
subscriptions[aggregate] = append(subscriptions[aggregate], sub)
}
return sub
}
func (es *Eventstore) notify(events []Event) {
subsMutex.RLock()
defer subsMutex.RUnlock()
for _, event := range events {
subs, ok := subscriptions[event.Aggregate().Type]
if !ok {
continue
}
for _, sub := range subs {
eventTypes := sub.types[event.Aggregate().Type]
//subscription for all events
if len(eventTypes) == 0 {
sub.Events <- event
continue
}
//subscription for certain events
if slices.Contains(eventTypes, event.Type()) {
select {
case sub.Events <- event:
default:
logging.Debug("unable to push event")
}
}
}
}
}
func (s *Subscription) Unsubscribe() {
subsMutex.Lock()
defer subsMutex.Unlock()
for aggregate := range s.types {
subs, ok := subscriptions[aggregate]
if !ok {
continue
}
for i := len(subs) - 1; i >= 0; i-- {
if subs[i] == s {
subs[i] = subs[len(subs)-1]
subs[len(subs)-1] = nil
subs = subs[:len(subs)-1]
}
}
}
_, ok := <-s.Events
if ok {
close(s.Events)
}
}