persist

type Adapter interface {
	// LoadPolicy loads all policy rules from the storage.
	LoadPolicy(model model.Model) error
	// SavePolicy saves all policy rules to the storage.
	SavePolicy(model model.Model) error

	// AddPolicy adds a policy rule to the storage.
	// This is part of the Auto-Save feature.
	AddPolicy(sec string, ptype string, rule []string) error
	// RemovePolicy removes a policy rule from the storage.
	// This is part of the Auto-Save feature.
	RemovePolicy(sec string, ptype string, rule []string) error
	// RemoveFilteredPolicy removes policy rules that match the filter from the storage.
	// This is part of the Auto-Save feature.
	RemoveFilteredPolicy(sec string, ptype string, fieldIndex int, fieldValues ...string) error
}

type FilteredAdapter interface {
	Adapter

	// LoadFilteredPolicy loads only policy rules that match the filter.
	LoadFilteredPolicy(model model.Model, filter interface{}) error
	// IsFiltered returns true if the loaded policy has been filtered.
	IsFiltered() bool
}

type Watcher interface {
	// SetUpdateCallback sets the callback function that the watcher will call
	// when the policy in DB has been changed by other instances.
	// A classic callback is Enforcer.LoadPolicy().
	SetUpdateCallback(func(string)) error
	// Update calls the update callback of other instances to synchronize their policy.
	// It is usually called after changing the policy in DB, like Enforcer.SavePolicy(),
	// Enforcer.AddPolicy(), Enforcer.RemovePolicy(), etc.
	Update() error
	// Close stops and releases the watcher, the callback function will not be called any more.
	Close()
}