resolver

type Address struct {
	// Addr is the server address on which a connection will be established.
	Addr string
	// Type is the type of this address.
	Type AddressType
	// ServerName is the name of this address.
	//
	// e.g. if Type is GRPCLB, ServerName should be the name of the remote load
	// balancer, not the name of the backend.
	ServerName string
	// Metadata is the information associated with Addr, which may be used
	// to make load balancing decision.
	Metadata interface{}
}

type AddressType uint8

type BuildOption struct {
	// DisableServiceConfig indicates whether resolver should fetch service config data.
	DisableServiceConfig bool
}

type Builder interface {
	// Build creates a new resolver for the given target.
	//
	// gRPC dial calls Build synchronously, and fails if the returned error is
	// not nil.
	Build(target Target, cc ClientConn, opts BuildOption) (Resolver, error)
	// Scheme returns the scheme supported by this resolver.
	// Scheme is defined at https://github.com/grpc/grpc/blob/master/doc/naming.md.
	Scheme() string
}

type ClientConn interface {
	// NewAddress is called by resolver to notify ClientConn a new list
	// of resolved addresses.
	// The address list should be the complete list of resolved addresses.
	NewAddress(addresses []Address)
	// NewServiceConfig is called by resolver to notify ClientConn a new
	// service config. The service config should be provided as a json string.
	NewServiceConfig(serviceConfig string)
}

type ResolveNowOption struct{}

type Resolver interface {
	// ResolveNow will be called by gRPC to try to resolve the target name
	// again. It's just a hint, resolver can ignore this if it's not necessary.
	//
	// It could be called multiple times concurrently.
	ResolveNow(ResolveNowOption)
	// Close closes the resolver.
	Close()
}

type Target struct {
	Scheme    string
	Authority string
	Endpoint  string
}