ActiveGo 1.8Package selector
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Variables
var (
DefaultSelector = newDefaultSelector()
ErrNotFound = errors.New("not found")
ErrNoneAvailable = errors.New("none available")
)
type Filter ¶
Filter is used to filter a service during the selection process
type Filter func([]*registry.Service) []*registry.Service
func FilterEndpoint ¶
func FilterEndpoint(name string) Filter
FilterEndpoint is an endpoint based Select Filter which will only return services with the endpoint specified.
func FilterLabel ¶
func FilterLabel(key, val string) Filter
FilterLabel is a label based Select Filter which will only return services with the label specified.
func FilterVersion ¶
func FilterVersion(version string) Filter
FilterVersion is a version based Select Filter which will only return services with the version specified.
type Next ¶
Next is a function that returns the next node based on the selector's strategy
type Next func() (*registry.Node, error)
func Random ¶
func Random(services []*registry.Service) Next
Random is a random strategy algorithm for node selection
func RoundRobin ¶
func RoundRobin(services []*registry.Service) Next
RoundRobin is a roundrobin strategy algorithm for node selection
type Option ¶
Option used to initialise the selector
type Option func(*Options)
func Registry ¶
func Registry(r registry.Registry) Option
Registry sets the registry used by the selector
func SetStrategy ¶
func SetStrategy(fn Strategy) Option
SetStrategy sets the default strategy for the selector
type Options ¶
type Options struct {
Registry registry.Registry
Strategy Strategy
// Other options for implementations of the interface
// can be stored in a context
Context context.Context
}
type SelectOption ¶
SelectOption used when making a select call
type SelectOption func(*SelectOptions)
func WithFilter ¶
func WithFilter(fn ...Filter) SelectOption
WithFilter adds a filter function to the list of filters used during the Select call.
func WithStrategy ¶
func WithStrategy(fn Strategy) SelectOption
Strategy sets the selector strategy
type SelectOptions ¶
type SelectOptions struct {
Filters []Filter
Strategy Strategy
// Other options for implementations of the interface
// can be stored in a context
Context context.Context
}
type Selector ¶
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
}
func NewSelector ¶
func NewSelector(opts ...Option) Selector
type Strategy ¶
Strategy is a selection strategy e.g random, round robin
type Strategy func([]*registry.Service) Next