xds

type Connection struct {
	// contains filtered or unexported fields
}

type ConnectionContext interface {
	XdsConnection() *Connection
	Watcher() Watcher
	// Initialize checks the first request.
	Initialize(node *core.Node) error
	// Close discards the connection.
	Close()
	// Process responds to a discovery request.
	Process(req *discovery.DiscoveryRequest) error
	// Push responds to a push event queue
	Push(ev any) error
}

type DiscoveryStream = discovery.AggregatedDiscoveryService_StreamAggregatedResourcesServer

type ResourceDelta struct {
	// Subscribed indicates the client requested these additional resources
	Subscribed sets.String
	// Unsubscribed indicates the client no longer requires these resources
	Unsubscribed sets.String
}

type Resources = []*discovery.Resource

type WatchedResource struct {
	// TypeUrl is copied from the DiscoveryRequest.TypeUrl that initiated watching this resource.
	// nolint
	TypeUrl string

	// ResourceNames tracks the list of resources that are actively watched.
	// For LDS and CDS, all resources of the TypeUrl type are watched if it is empty.
	// For endpoints the resource names will have list of clusters and for clusters it is empty.
	// For Delta Xds, all resources of the TypeUrl that a client has subscribed to.
	ResourceNames []string

	// Wildcard indicates the subscription is a wildcard subscription. This only applies to types that
	// allow both wildcard and non-wildcard subscriptions.
	Wildcard bool

	// NonceSent is the nonce sent in the last sent response. If it is equal with NonceAcked, the
	// last message has been processed. If empty: we never sent a message of this type.
	NonceSent string

	// NonceAcked is the last acked message.
	NonceAcked string

	// AlwaysRespond, if true, will ensure that even when a request would otherwise be treated as an
	// ACK, it will be responded to. This typically happens when a proxy reconnects to another instance of
	// Istiod. In that case, Envoy expects us to respond to EDS/RDS/SDS requests to finish warming of
	// clusters/listeners.
	// Typically, this should be set to 'false' after response; keeping it true would likely result in an endless loop.
	AlwaysRespond bool

	// LastResources tracks the contents of the last push.
	// This field is extremely expensive to maintain and is typically disabled
	LastResources Resources
}

type Watcher interface {
	DeleteWatchedResource(url string)
	GetWatchedResource(url string) *WatchedResource
	NewWatchedResource(url string, names []string)
	UpdateWatchedResource(string, func(*WatchedResource) *WatchedResource)
	// GetID identifies an xDS client. This is different from a connection ID.
	GetID() string
}