sd

Documentation

Overview

Package sd, provide base implementation of discovery.Client and discovery.Instancer.

Index

• Constants
• func NewSimpleServiceCache() discovery.ServiceCache
• type CachedInstancer
  • func MakeCachedInstancer(opts ...CachedInstancerOptions) CachedInstancer
  • func (i *CachedInstancer) DeregisterCallback(id interface{})
  • func (i *CachedInstancer) Instances(matcher discovery.InstanceMatcher) (ret []*discovery.Instance, err error)
  • func (i *CachedInstancer) RefreshNow(ctx context.Context) (*discovery.Service, error)
  • func (i *CachedInstancer) RegisterCallback(id interface{}, cb discovery.Callback)
  • func (i *CachedInstancer) Service() (svc *discovery.Service)
  • func (i *CachedInstancer) ServiceName() string
  • func (i *CachedInstancer) Start(ctx context.Context)
  • func (i *CachedInstancer) Stop()
• type CachedInstancerOption
• type CachedInstancerOptions
• type InstancerOption
• type RefreshFunc

Constants

const (
	DefaultRefreshBackoffFactor float64 = 1.5
)

Functions

func NewSimpleServiceCache

func NewSimpleServiceCache() discovery.ServiceCache

NewSimpleServiceCache returns a ServiceCache with map[string]*Service as a back storage This ServiceCache is not goroutine-safe

Types

type CachedInstancer

type CachedInstancer struct {
	CachedInstancerOption
	// contains filtered or unexported fields
}

CachedInstancer implements discovery.Instancer CachedInstancer provides common implementation of discovery.Instancer with an internal cache and a background goroutine to periodically refresh service cache using provided RefreshFunc. See discovery.Instancer

func MakeCachedInstancer

func MakeCachedInstancer(opts ...CachedInstancerOptions) CachedInstancer

MakeCachedInstancer returns a CachedInstancer that provide basic implementation of discovery.Instancer See discovery.Instancer

func (*CachedInstancer) DeregisterCallback

func (i *CachedInstancer) DeregisterCallback(id interface{})

func (*CachedInstancer) Instances

func (i *CachedInstancer) Instances(matcher discovery.InstanceMatcher) (ret []*discovery.Instance, err error)

Instances implements discovery.Instancer

func (*CachedInstancer) RefreshNow

func (i *CachedInstancer) RefreshNow(ctx context.Context) (*discovery.Service, error)

RefreshNow invoke refresh task immediately in current goroutine. Note: refresh function is run in current goroutine

func (*CachedInstancer) RegisterCallback

func (i *CachedInstancer) RegisterCallback(id interface{}, cb discovery.Callback)

func (*CachedInstancer) Service

func (i *CachedInstancer) Service() (svc *discovery.Service)

Service implements discovery.Instancer

func (*CachedInstancer) ServiceName

func (i *CachedInstancer) ServiceName() string

ServiceName implements discovery.Instancer

func (*CachedInstancer) Start

func (i *CachedInstancer) Start(ctx context.Context)

func (*CachedInstancer) Stop

func (i *CachedInstancer) Stop()

Stop implements discovery.Instancer.

type CachedInstancerOption

type CachedInstancerOption struct {
	InstancerOption

	// BackgroundRefreshFunc is used for background cache refresh.
	// This function is repeated in a loop.Loop, so following behavior is guaranteed:
	// - Sequential execution is guaranteed, no concurrent conditions between execution need to considered.
	// - Next execution is not scheduled until current execution finishes. So this function can block current goroutine.
	//   The repeat interval is configurable via InstancerOption.RefresherOptions
	BackgroundRefreshFunc RefreshFunc
	// ForegroundRefreshFunc is used for foreground cache refresh, directly invoked via CachedInstancer.RefreshNow.
	// This function always invoked in current goroutine. So concurrent conditions need to be considered,
	// and cancellation/timeout need to be taken care of
	ForegroundRefreshFunc RefreshFunc
}

type CachedInstancerOptions

type CachedInstancerOptions func(opt *CachedInstancerOption)

CachedInstancerOptions used to create CachedInstancer

type InstancerOption

type InstancerOption struct {
	// Name service name
	Name string
	// Logger logger to use for
	Logger log.ContextualLogger
	// Verbose whether to create logs for internal state changes
	Verbose bool
	// RefresherOptions controls how service refresher to retry refreshing attempt in case of failure.
	// Default is loop.ExponentialRepeatIntervalOnError with initial interval 50ms and factor 1.5
	RefresherOptions []loop.TaskOptions
}

InstancerOption general options applicable to any cache based instancer implementation

type RefreshFunc

type RefreshFunc func(ctx context.Context) (*discovery.Service, error)

RefreshFunc is the function to use when CachedInstancer try to refresh internal cache. The refresh result is automatically saved and notified (if there is change)