picker

Documentation

Index

• type Picker
  • func NewPicker(r Remotes, initial ...string) *Picker
  • func (p *Picker) Close() error
  • func (p *Picker) Init(cc *grpc.ClientConn) error
  • func (p *Picker) Pick(ctx context.Context) (transport.ClientTransport, error)
  • func (p *Picker) PickAddr() (string, error)
  • func (p *Picker) Reset() error
  • func (p *Picker) State() (grpc.ConnectivityState, error)
  • func (p *Picker) WaitForStateChange(ctx context.Context, sourceState grpc.ConnectivityState) (grpc.ConnectivityState, error)
• type Remotes
  • func NewRemotes(peers ...api.Peer) Remotes

Types

type Picker

type Picker struct {
	// contains filtered or unexported fields
}

Picker implements a grpc Picker

func NewPicker

func NewPicker(r Remotes, initial ...string) *Picker

NewPicker returns a Picker

func (*Picker) Close

func (p *Picker) Close() error

Close closes all the Conn's owned by this Picker.

func (*Picker) Init

func (p *Picker) Init(cc *grpc.ClientConn) error

Init does initial processing for the Picker, e.g., initiate some connections.

func (*Picker) Pick

func (p *Picker) Pick(ctx context.Context) (transport.ClientTransport, error)

Pick blocks until either a transport.ClientTransport is ready for the upcoming RPC or some error happens.

func (*Picker) PickAddr

func (p *Picker) PickAddr() (string, error)

PickAddr picks a peer address for connecting. This will be called repeated for connecting/reconnecting.

func (*Picker) Reset

func (p *Picker) Reset() error

Reset the current connection and force a reconnect to another address.

func (*Picker) State

func (p *Picker) State() (grpc.ConnectivityState, error)

State returns the connectivity state of the underlying connections.

func (*Picker) WaitForStateChange

func (p *Picker) WaitForStateChange(ctx context.Context, sourceState grpc.ConnectivityState) (grpc.ConnectivityState, error)

WaitForStateChange blocks until the state changes to something other than the sourceState. It returns the new state or error.

type Remotes

type Remotes interface {
	// Weight returns the remotes with their current weights.
	Weights() map[api.Peer]int

	// Select a remote from the set of available remotes with optionally
	// excluding ID or address.
	Select(...string) (api.Peer, error)

	// Observe records an experience with a particular remote. A positive weight
	// indicates a good experience and a negative weight a bad experience.
	//
	// The observation will be used to calculate a moving weight, which is
	// implementation dependent. This method will be called such that repeated
	// observations of the same master in each session request are favored.
	Observe(peer api.Peer, weight int)

	// ObserveIfExists records an experience with a particular remote if when a
	// remote exists.
	ObserveIfExists(peer api.Peer, weight int)

	// Remove the remote from the list completely.
	Remove(addrs ...api.Peer)
}

Remotes keeps track of remote addresses by weight, informed by observations.

func NewRemotes

func NewRemotes(peers ...api.Peer) Remotes

NewRemotes returns a Remotes instance with the provided set of addresses. Entries provided are heavily weighted initially.