peerstore

Documentation

Overview

Package peerstore provides types and interfaces for local storage of address information, metadata, and public key material about libp2p peers.

Index

• Constants
• Variables
• type AddrBook
• type KeyBook
• type Metrics
• type PeerMetadata
• type Peerstore
• type ProtoBook

Constants

const (
	// PermanentAddrTTL is the ttl for a "permanent address" (e.g. bootstrap nodes).
	PermanentAddrTTL = math.MaxInt64 - iota

	// ConnectedAddrTTL is the ttl used for the addresses of a peer to whom
	// we're connected directly. This is basically permanent, as we will
	// clear them + re-add under a TempAddrTTL after disconnecting.
	ConnectedAddrTTL
)

Permanent TTLs (distinct so we can distinguish between them, constant as they are, in fact, permanent)

Variables

var (
	// AddressTTL is the expiration time of addresses.
	AddressTTL = time.Hour

	// TempAddrTTL is the ttl used for a short lived address
	TempAddrTTL = time.Minute * 2

	// ProviderAddrTTL is the TTL of an address we've received from a provider.
	// This is also a temporary address, but lasts longer. After this expires,
	// the records we return will require an extra lookup.
	ProviderAddrTTL = time.Minute * 10

	// RecentlyConnectedAddrTTL is used when we recently connected to a peer.
	// It means that we are reasonably certain of the peer's address.
	RecentlyConnectedAddrTTL = time.Minute * 10

	// OwnObservedAddrTTL is used for our own external addresses observed by peers.
	OwnObservedAddrTTL = time.Minute * 10
)

var ErrNotFound = errors.New("item not found")

Types

type AddrBook

type AddrBook interface {

	// AddAddr calls AddAddrs(p, []ma.Multiaddr{addr}, ttl)
	AddAddr(p peer.ID, addr ma.Multiaddr, ttl time.Duration)

	// AddAddrs gives this AddrBook addresses to use, with a given ttl
	// (time-to-live), after which the address is no longer valid.
	// If the manager has a longer TTL, the operation is a no-op for that address
	AddAddrs(p peer.ID, addrs []ma.Multiaddr, ttl time.Duration)

	// SetAddr calls mgr.SetAddrs(p, addr, ttl)
	SetAddr(p peer.ID, addr ma.Multiaddr, ttl time.Duration)

	// SetAddrs sets the ttl on addresses. This clears any TTL there previously.
	// This is used when we receive the best estimate of the validity of an address.
	SetAddrs(p peer.ID, addrs []ma.Multiaddr, ttl time.Duration)

	// UpdateAddrs updates the addresses associated with the given peer that have
	// the given oldTTL to have the given newTTL.
	UpdateAddrs(p peer.ID, oldTTL time.Duration, newTTL time.Duration)

	// Addresses returns all known (and valid) addresses for a given peer
	Addrs(p peer.ID) []ma.Multiaddr

	// AddrStream returns a channel that gets all addresses for a given
	// peer sent on it. If new addresses are added after the call is made
	// they will be sent along through the channel as well.
	AddrStream(context.Context, peer.ID) <-chan ma.Multiaddr

	// ClearAddresses removes all previously stored addresses
	ClearAddrs(p peer.ID)

	// PeersWithAddrs returns all of the peer IDs stored in the AddrBook
	PeersWithAddrs() peer.IDSlice
}

AddrBook holds the multiaddrs of peers.

type KeyBook

type KeyBook interface {
	// PubKey stores the public key of a peer.
	PubKey(peer.ID) ic.PubKey

	// AddPubKey stores the public key of a peer.
	AddPubKey(peer.ID, ic.PubKey) error

	// PrivKey returns the private key of a peer, if known. Generally this might only be our own
	// private key, see
	// https://discuss.libp2p.io/t/what-is-the-purpose-of-having-map-peer-id-privatekey-in-peerstore/74.
	PrivKey(peer.ID) ic.PrivKey

	// AddPrivKey stores the private key of a peer.
	AddPrivKey(peer.ID, ic.PrivKey) error

	// PeersWithKeys returns all the peer IDs stored in the KeyBook
	PeersWithKeys() peer.IDSlice
}

KeyBook tracks the keys of Peers.

type Metrics

type Metrics interface {
	// RecordLatency records a new latency measurement
	RecordLatency(peer.ID, time.Duration)

	// LatencyEWMA returns an exponentially-weighted moving avg.
	// of all measurements of a peer's latency.
	LatencyEWMA(peer.ID) time.Duration
}

Metrics is just an object that tracks metrics across a set of peers.

type PeerMetadata

type PeerMetadata interface {
	// Get/Put is a simple registry for other peer-related key/value pairs.
	// if we find something we use often, it should become its own set of
	// methods. this is a last resort.
	Get(p peer.ID, key string) (interface{}, error)
	Put(p peer.ID, key string, val interface{}) error
}

PeerMetadata can handle values of any type. Serializing values is up to the implementation. Dynamic type introspection may not be supported, in which case explicitly enlisting types in the serializer may be required.

Refer to the docs of the underlying implementation for more information.

type Peerstore

type Peerstore interface {
	io.Closer

	AddrBook
	KeyBook
	PeerMetadata
	Metrics
	ProtoBook

	// PeerInfo returns a peer.PeerInfo struct for given peer.ID.
	// This is a small slice of the information Peerstore has on
	// that peer, useful to other services.
	PeerInfo(peer.ID) peer.AddrInfo

	// Peers returns all of the peer IDs stored across all inner stores.
	Peers() peer.IDSlice
}

Peerstore provides a threadsafe store of Peer related information.

type ProtoBook

type ProtoBook interface {
	GetProtocols(peer.ID) ([]string, error)
	AddProtocols(peer.ID, ...string) error
	SetProtocols(peer.ID, ...string) error
	RemoveProtocols(peer.ID, ...string) error
	SupportsProtocols(peer.ID, ...string) ([]string, error)
}

ProtoBook tracks the protocols supported by peers