Files
argo-cd/server/application/broadcaster.go
2025-05-20 15:48:09 -04:00

97 lines
2.7 KiB
Go

package application
import (
"sync"
log "github.com/sirupsen/logrus"
"k8s.io/apimachinery/pkg/watch"
appv1 "github.com/argoproj/argo-cd/v3/pkg/apis/application/v1alpha1"
applog "github.com/argoproj/argo-cd/v3/util/app/log"
)
type subscriber struct {
ch chan *appv1.ApplicationWatchEvent
filters []func(*appv1.ApplicationWatchEvent) bool
}
func (s *subscriber) matches(event *appv1.ApplicationWatchEvent) bool {
for i := range s.filters {
if !s.filters[i](event) {
return false
}
}
return true
}
// Broadcaster is an interface for broadcasting application informer watch events to multiple subscribers.
type Broadcaster interface {
Subscribe(ch chan *appv1.ApplicationWatchEvent, filters ...func(event *appv1.ApplicationWatchEvent) bool) func()
OnAdd(any, bool)
OnUpdate(any, any)
OnDelete(any)
}
type broadcasterHandler struct {
lock sync.Mutex
subscribers []*subscriber
}
func (b *broadcasterHandler) notify(event *appv1.ApplicationWatchEvent) {
// Make a local copy of b.subscribers, then send channel events outside the lock,
// to avoid data race on b.subscribers changes
subscribers := []*subscriber{}
b.lock.Lock()
subscribers = append(subscribers, b.subscribers...)
b.lock.Unlock()
for _, s := range subscribers {
if s.matches(event) {
select {
case s.ch <- event:
default:
// drop event if cannot send right away
log.WithFields(applog.GetAppLogFields(&event.Application)).Warn("unable to send event notification")
}
}
}
}
// Subscribe forward application informer watch events to the provided channel.
// The watch events are dropped if no receives are reading events from the channel so the channel must have
// buffer if dropping events is not acceptable.
func (b *broadcasterHandler) Subscribe(ch chan *appv1.ApplicationWatchEvent, filters ...func(event *appv1.ApplicationWatchEvent) bool) func() {
b.lock.Lock()
defer b.lock.Unlock()
subscriber := &subscriber{ch, filters}
b.subscribers = append(b.subscribers, subscriber)
return func() {
b.lock.Lock()
defer b.lock.Unlock()
for i := range b.subscribers {
if b.subscribers[i] == subscriber {
b.subscribers = append(b.subscribers[:i], b.subscribers[i+1:]...)
break
}
}
}
}
func (b *broadcasterHandler) OnAdd(obj any, _ bool) {
if app, ok := obj.(*appv1.Application); ok {
b.notify(&appv1.ApplicationWatchEvent{Application: *app, Type: watch.Added})
}
}
func (b *broadcasterHandler) OnUpdate(_, newObj any) {
if app, ok := newObj.(*appv1.Application); ok {
b.notify(&appv1.ApplicationWatchEvent{Application: *app, Type: watch.Modified})
}
}
func (b *broadcasterHandler) OnDelete(obj any) {
if app, ok := obj.(*appv1.Application); ok {
b.notify(&appv1.ApplicationWatchEvent{Application: *app, Type: watch.Deleted})
}
}