dht

Documentation

Overview

Package dht implements a distributed hash table that satisfies the ipfs routing interface. This DHT is modeled after kademlia with Coral and S/Kademlia modifications.

Package dht implements a distributed hash table that satisfies the ipfs routing interface. This DHT is modeled after kademlia with Coral and S/Kademlia modifications.

Index

• Constants
• Variables
• type BootstrapConfig
• type IpfsDHT
  • func NewDHT(ctx context.Context, h host.Host, dstore ds.Batching) *IpfsDHT
  • func (dht *IpfsDHT) Bootstrap(ctx context.Context) error
  • func (dht *IpfsDHT) BootstrapOnSignal(cfg BootstrapConfig, signal <-chan time.Time) (goprocess.Process, error)
  • func (dht *IpfsDHT) BootstrapWithConfig(config BootstrapConfig) (goprocess.Process, error)
  • func (dht *IpfsDHT) Close() error
  • func (dht *IpfsDHT) Context() context.Context
  • func (dht *IpfsDHT) FindLocal(id peer.ID) pstore.PeerInfo
  • func (dht *IpfsDHT) FindPeer(ctx context.Context, id peer.ID) (pstore.PeerInfo, error)
  • func (dht *IpfsDHT) FindPeersConnectedToPeer(ctx context.Context, id peer.ID) (<-chan pstore.PeerInfo, error)
  • func (dht *IpfsDHT) FindProviders(ctx context.Context, key key.Key) ([]pstore.PeerInfo, error)
  • func (dht *IpfsDHT) FindProvidersAsync(ctx context.Context, key key.Key, count int) <-chan pstore.PeerInfo
  • func (dht *IpfsDHT) GetClosestPeers(ctx context.Context, key key.Key) (<-chan peer.ID, error)
  • func (dht *IpfsDHT) GetPublicKey(ctx context.Context, p peer.ID) (ci.PubKey, error)
  • func (dht *IpfsDHT) GetValue(ctx context.Context, key key.Key) ([]byte, error)
  • func (dht *IpfsDHT) GetValues(ctx context.Context, key key.Key, nvals int) ([]routing.RecvdVal, error)
  • func (dht *IpfsDHT) Process() goprocess.Process
  • func (dht *IpfsDHT) Provide(ctx context.Context, key key.Key) error
  • func (dht *IpfsDHT) PutValue(ctx context.Context, key key.Key, value []byte) error
  • func (dht *IpfsDHT) Update(ctx context.Context, p peer.ID)

Constants

const MaxRecordAge = time.Hour * 36

MaxRecordAge specifies the maximum time that any node will hold onto a record from the time its received. This does not apply to any other forms of validity that the record may contain. For example, a record may contain an ipns entry with an EOL saying its valid until the year 2020 (a great time in the future). For that record to stick around it must be rebroadcasted more frequently than once every 'MaxRecordAge'

const NumBootstrapQueries = 5

NumBootstrapQueries defines the number of random dht queries to do to collect members of the routing table.

Variables

var AlphaValue = 3

Alpha is the concurrency factor for asynchronous requests.

var CloserPeerCount = KValue

The number of closer peers to send on requests.

var DefaultBootstrapConfig = BootstrapConfig{

	Queries: 1,

	Period: time.Duration(5 * time.Minute),

	Timeout: time.Duration(10 * time.Second),
}

var ErrReadTimeout = fmt.Errorf("timed out reading response")

var KValue = 20

K is the maximum number of requests to perform before returning failure.

var PoolSize = 6

Pool size is the number of nodes used for group find/set RPC calls

var ProtocolDHT protocol.ID = "/ipfs/dht"

Types

type BootstrapConfig

type BootstrapConfig struct {
	Queries int           // how many queries to run per period
	Period  time.Duration // how often to run periodi cbootstrap.
	Timeout time.Duration // how long to wait for a bootstrao query to run
}

BootstrapConfig specifies parameters used bootstrapping the DHT.

Note there is a tradeoff between the bootstrap period and the number of queries. We could support a higher period with less queries.

type IpfsDHT

type IpfsDHT struct {
	Validator record.Validator // record validator funcs
	Selector  record.Selector  // record selection funcs
	// contains filtered or unexported fields
}

IpfsDHT is an implementation of Kademlia with Coral and S/Kademlia modifications. It is used to implement the base IpfsRouting module.

func NewDHT

func NewDHT(ctx context.Context, h host.Host, dstore ds.Batching) *IpfsDHT

NewDHT creates a new DHT object with the given peer as the 'local' host

func (*IpfsDHT) Bootstrap

func (dht *IpfsDHT) Bootstrap(ctx context.Context) error

Bootstrap ensures the dht routing table remains healthy as peers come and go. it builds up a list of peers by requesting random peer IDs. The Bootstrap process will run a number of queries each time, and run every time signal fires. These parameters are configurable.

As opposed to BootstrapWithConfig, Bootstrap satisfies the routing interface

func (*IpfsDHT) BootstrapOnSignal

func (dht *IpfsDHT) BootstrapOnSignal(cfg BootstrapConfig, signal <-chan time.Time) (goprocess.Process, error)

SignalBootstrap ensures the dht routing table remains healthy as peers come and go. it builds up a list of peers by requesting random peer IDs. The Bootstrap process will run a number of queries each time, and run every time signal fires. These parameters are configurable.

SignalBootstrap returns a process, so the user can stop it.

func (*IpfsDHT) BootstrapWithConfig

func (dht *IpfsDHT) BootstrapWithConfig(config BootstrapConfig) (goprocess.Process, error)

BootstrapWithConfig ensures the dht routing table remains healthy as peers come and go. it builds up a list of peers by requesting random peer IDs. The Bootstrap process will run a number of queries each time, and run every time signal fires. These parameters are configurable.

BootstrapWithConfig returns a process, so the user can stop it.

func (*IpfsDHT) Close

func (dht *IpfsDHT) Close() error

Close calls Process Close

func (*IpfsDHT) Context

func (dht *IpfsDHT) Context() context.Context

Context return dht's context

func (*IpfsDHT) FindLocal

func (dht *IpfsDHT) FindLocal(id peer.ID) pstore.PeerInfo

FindLocal looks for a peer with a given ID connected to this dht and returns the peer and the table it was found in.

func (*IpfsDHT) FindPeer

func (dht *IpfsDHT) FindPeer(ctx context.Context, id peer.ID) (pstore.PeerInfo, error)

FindPeer searches for a peer with given ID.

func (*IpfsDHT) FindPeersConnectedToPeer

func (dht *IpfsDHT) FindPeersConnectedToPeer(ctx context.Context, id peer.ID) (<-chan pstore.PeerInfo, error)

FindPeersConnectedToPeer searches for peers directly connected to a given peer.

func (*IpfsDHT) FindProviders

func (dht *IpfsDHT) FindProviders(ctx context.Context, key key.Key) ([]pstore.PeerInfo, error)

FindProviders searches until the context expires.

func (*IpfsDHT) FindProvidersAsync

func (dht *IpfsDHT) FindProvidersAsync(ctx context.Context, key key.Key, count int) <-chan pstore.PeerInfo

FindProvidersAsync is the same thing as FindProviders, but returns a channel. Peers will be returned on the channel as soon as they are found, even before the search query completes.

func (*IpfsDHT) GetClosestPeers

func (dht *IpfsDHT) GetClosestPeers(ctx context.Context, key key.Key) (<-chan peer.ID, error)

Kademlia 'node lookup' operation. Returns a channel of the K closest peers to the given key

func (*IpfsDHT) GetPublicKey

func (dht *IpfsDHT) GetPublicKey(ctx context.Context, p peer.ID) (ci.PubKey, error)

func (*IpfsDHT) GetValue

func (dht *IpfsDHT) GetValue(ctx context.Context, key key.Key) ([]byte, error)

GetValue searches for the value corresponding to given Key.

func (*IpfsDHT) GetValues

func (dht *IpfsDHT) GetValues(ctx context.Context, key key.Key, nvals int) ([]routing.RecvdVal, error)

func (*IpfsDHT) Process

func (dht *IpfsDHT) Process() goprocess.Process

Process return dht's process

func (*IpfsDHT) Provide

func (dht *IpfsDHT) Provide(ctx context.Context, key key.Key) error

Provide makes this node announce that it can provide a value for the given key

func (*IpfsDHT) PutValue

func (dht *IpfsDHT) PutValue(ctx context.Context, key key.Key, value []byte) error

PutValue adds value corresponding to given Key. This is the top level "Store" operation of the DHT

func (*IpfsDHT) Update

func (dht *IpfsDHT) Update(ctx context.Context, p peer.ID)

Update signals the routingTable to Update its last-seen status on the given peer.