package selector import ( "errors" "github.com/micro/go-micro/registry" ) // Selector builds on the registry as a mechanism to pick nodes // and mark their status. This allows host pools and other things // to be built using various algorithms. type Selector interface { Init(opts ...Option) error Options() Options // Select returns a function which should return the next node Select(service string, opts ...SelectOption) (Next, error) // Mark sets the success/error against a node Mark(service string, node *registry.Node, err error) // Reset returns state back to zero for a service Reset(service string) // Close renders the selector unusable Close() error // Name of the selector String() string } // Next is a function that returns the next node // based on the selector's strategy type Next func() (*registry.Node, error) // Filter is used to filter a service during the selection process type Filter func([]*registry.Service) []*registry.Service // Strategy is a selection strategy e.g random, round robin type Strategy func([]*registry.Service) Next var ( DefaultSelector = newDefaultSelector() ErrNotFound = errors.New("not found") ErrNoneAvailable = errors.New("none available") ) func NewSelector(opts ...Option) Selector { return newDefaultSelector(opts...) }