package main import ( "sync" "github.com/gofrs/uuid/v3" ) type ( hooker struct { hooks map[string]func() lock sync.RWMutex } ) func newHooker() *hooker { return &hooker{hooks: map[string]func(){}} } func (h *hooker) Ping() { h.lock.RLock() defer h.lock.RUnlock() for _, hf := range h.hooks { hf() } } func (h *hooker) Register(hook func()) func() { h.lock.Lock() defer h.lock.Unlock() id := uuid.Must(uuid.NewV4()).String() h.hooks[id] = hook return func() { h.unregister(id) } } func (h *hooker) unregister(id string) { h.lock.Lock() defer h.lock.Unlock() delete(h.hooks, id) }