selector

Documentation

Index

• Variables
• type Mode
  • func (s Mode) String() string
• type ModeFunc
  • func SelectorNext(mode Mode) ModeFunc
• type NewSelector
• type Next
• type Option
  • func Context(ctx context.Context) Option
  • func Registry(r registry.Registry) Option
  • func SelectMode(mode Mode) Option
• type Options
• type Selector

Variables

var (
	ErrNotFound              = errors.New("not found")
	ErrNoneAvailable         = errors.New("none available")
	ErrRunOutAllServiceNodes = errors.New("has used out all provider nodes")
)

Types

type Mode

type Mode int

Mode defines the algorithm of selecting a provider from cluster

const (
	SM_BEGIN Mode = iota
	SM_Random
	SM_RoundRobin
	SM_END
)

func (Mode) String

func (s Mode) String() string

type ModeFunc

type ModeFunc func([]*registry.ServiceURL) Next

func SelectorNext

func SelectorNext(mode Mode) ModeFunc

type NewSelector

type NewSelector func(...Option) Selector

type Next

type Next func(ID int64) (*registry.ServiceURL, error)

Next is a function that returns the next node based on the selector's strategy

type Option

type Option func(*Options)

Option used to initialise the selector

func Context

func Context(ctx context.Context) Option

func Registry

func Registry(r registry.Registry) Option

Registry sets the registry used by the selector

func SelectMode

func SelectMode(mode Mode) Option

SetStrategy sets the default strategy for the selector

type Options

type Options struct {
	Registry registry.Registry
	Mode     Mode // selector mode

	// Other options for implementations of the interface
	// can be stored in a context
	Context context.Context
}

type Selector

type Selector interface {
	Options() Options
	// Select returns a function which should return the next node
	Select(conf registry.ServiceConfigIf) (Next, error)
	// Close renders the selector unusable
	Close() error
	// Name of the selector
	String() string
}

Selector builds on the registry as a mechanism to pick nodes. This allows host pools and other things to be built using various algorithms.