dht

Documentation

Index

• Variables
• type CallbackContentResolver
  • func (r CallbackContentResolver) InsertContent(id, content []byte)
  • func (r CallbackContentResolver) QueryContent(id []byte) ([]byte, bool)
• type ContentResolver
• type DoubleCacheContentResolver
  • func NewDoubleCacheContentResolver(opts DoubleCacheContentResolverOptions, next ContentResolver) *DoubleCacheContentResolver
  • func (r *DoubleCacheContentResolver) InsertContent(id, content []byte)
  • func (r *DoubleCacheContentResolver) QueryContent(id []byte) ([]byte, bool)
• type DoubleCacheContentResolverOptions
  • func DefaultDoubleCacheContentResolverOptions() DoubleCacheContentResolverOptions
  • func (opts DoubleCacheContentResolverOptions) WithCapacity(capacity int) DoubleCacheContentResolverOptions
• type Expiry
• type InMemTable
  • func NewInMemTable(self id.Signatory) *InMemTable
  • func (table *InMemTable) AddExpiry(peerID id.Signatory, duration time.Duration)
  • func (table *InMemTable) AddPeer(peerID id.Signatory, peerAddr wire.Address)
  • func (table *InMemTable) AddSubnet(signatories []id.Signatory) id.Hash
  • func (table *InMemTable) DeleteExpiry(peerID id.Signatory)
  • func (table *InMemTable) DeletePeer(peerID id.Signatory)
  • func (table *InMemTable) DeleteSubnet(hash id.Hash)
  • func (table *InMemTable) HandleExpired(peerID id.Signatory) bool
  • func (table *InMemTable) NumPeers() int
  • func (table *InMemTable) PeerAddress(peerID id.Signatory) (wire.Address, bool)
  • func (table *InMemTable) Peers(n int) []id.Signatory
  • func (table *InMemTable) RandomPeers(n int) []id.Signatory
  • func (table *InMemTable) Self() id.Signatory
  • func (table *InMemTable) Subnet(hash id.Hash) []id.Signatory
• type Table

Variables

var (
	// DefaultDoubleCacheContentResolverCapacity defines the default in-memory
	// cache capacity (in bytes) for the double-cache content resolver.
	DefaultDoubleCacheContentResolverCapacity = 16 * 1024 * 1024 // 16 MB
)

Types

type CallbackContentResolver

type CallbackContentResolver struct {
	InsertContentCallback func([]byte, []byte)
	QueryContentCallback  func([]byte) ([]byte, bool)
}

CallbackContentResolver implements the ContentResolve interface by delegating all logic to callback functions. This is useful when defining an implementation inline.

func (CallbackContentResolver) InsertContent

func (r CallbackContentResolver) InsertContent(id, content []byte)

InsertContent will delegate the implementation to the InsertContentCallback. If the callback is nil, then this method will do nothing.

func (CallbackContentResolver) QueryContent

func (r CallbackContentResolver) QueryContent(id []byte) ([]byte, bool)

QueryContent will delegate the implementation to the QueryContentCallback. If the callback is nil, then this method will return false.

type ContentResolver

type ContentResolver interface {
	// Insert content with a specific content ID. Usually, the content ID will
	// stores information about the type and the hash of the content.
	InsertContent(contentID, content []byte)

	// QueryContent returns the content associated with a content ID. If there
	// is no associated content, it returns false. Otherwise, it returns true.
	QueryContent(contentID []byte) (content []byte, contentOk bool)
}

The ContentResolver interface is used to insert and query content.

type DoubleCacheContentResolver

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

The DoubleCacheContentResolver uses the double-cache technique to implement a fast in-memory cache. The cache can optionally wrap around another content-resolver (which can be responsible for more persistent content resolution).

func NewDoubleCacheContentResolver

func NewDoubleCacheContentResolver(opts DoubleCacheContentResolverOptions, next ContentResolver) *DoubleCacheContentResolver

NewDoubleCacheContentResolver returns a new double-cache content resolver that is wrapped around another content-resolver.

func (*DoubleCacheContentResolver) InsertContent

func (r *DoubleCacheContentResolver) InsertContent(id, content []byte)

InsertContent into the double-cache content resolver. If the front cache is full, it will be rotated to the back, the current back cache will be dropped, and a new front cache will be created. This method will also insert the content to the next content resovler (if one exists).

func (*DoubleCacheContentResolver) QueryContent

func (r *DoubleCacheContentResolver) QueryContent(id []byte) ([]byte, bool)

QueryContent returns the content associated with the given content ID. If the content is not found in the double-cache content resolver, the next content resolver will be checked (if one exists).

type DoubleCacheContentResolverOptions

type DoubleCacheContentResolverOptions struct {
	Capacity int
}

DoubleCacheContentResolverOptions for parameterising the behaviour of the DoubleCacheContentResolver.

func DefaultDoubleCacheContentResolverOptions

func DefaultDoubleCacheContentResolverOptions() DoubleCacheContentResolverOptions

DefaultDoubleCacheContentResolverOptions returns the default DoubleCacheContentResolverOptions.

func (DoubleCacheContentResolverOptions) WithCapacity

func (opts DoubleCacheContentResolverOptions) WithCapacity(capacity int) DoubleCacheContentResolverOptions

WithCapacity sets the maximum in-memory cache capacity (in bytes). This capacity accounts for the fact that the double-cache content resolver has two in-memory buffers. For example, if the capacity is set to 2 MB, then the double-cache content resolver is guaranteeed to consume, at most, 2 MB of memory, but will only be able to cache 1 MB of data.

type Expiry

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

type InMemTable

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

InMemTable implements the Table using in-memory storage.

func NewInMemTable

func NewInMemTable(self id.Signatory) *InMemTable

func (*InMemTable) AddExpiry

func (table *InMemTable) AddExpiry(peerID id.Signatory, duration time.Duration)

func (*InMemTable) AddPeer

func (table *InMemTable) AddPeer(peerID id.Signatory, peerAddr wire.Address)

func (*InMemTable) AddSubnet

func (table *InMemTable) AddSubnet(signatories []id.Signatory) id.Hash

func (*InMemTable) DeleteExpiry

func (table *InMemTable) DeleteExpiry(peerID id.Signatory)

func (*InMemTable) DeletePeer

func (table *InMemTable) DeletePeer(peerID id.Signatory)

func (*InMemTable) DeleteSubnet

func (table *InMemTable) DeleteSubnet(hash id.Hash)

func (*InMemTable) HandleExpired

func (table *InMemTable) HandleExpired(peerID id.Signatory) bool

func (*InMemTable) NumPeers

func (table *InMemTable) NumPeers() int

func (*InMemTable) PeerAddress

func (table *InMemTable) PeerAddress(peerID id.Signatory) (wire.Address, bool)

func (*InMemTable) Peers

func (table *InMemTable) Peers(n int) []id.Signatory

Peers returns the n closest peer IDs.

func (*InMemTable) RandomPeers

func (table *InMemTable) RandomPeers(n int) []id.Signatory

RandomPeers returns n random peer IDs

func (*InMemTable) Self

func (table *InMemTable) Self() id.Signatory

func (*InMemTable) Subnet

func (table *InMemTable) Subnet(hash id.Hash) []id.Signatory

type Table

type Table interface {
	// Self returns the local peer. It does not return the network address of
	// the local peer, because it can change frequently, and is not guaranteed
	// to exist.
	Self() id.Signatory

	// AddPeer to the table with an associate network address.
	AddPeer(id.Signatory, wire.Address)
	// DeletePeer from the table.
	DeletePeer(id.Signatory)
	// PeerAddress returns the network address associated with the given peer.
	PeerAddress(id.Signatory) (wire.Address, bool)

	// Peers returns the n closest peers to the local peer, using XORing as the
	// measure of distance between two peers.
	Peers(int) []id.Signatory
	// RandomPeers returns n random peer IDs, using either partial permutation
	// or Floyd's sampling algorithm.
	RandomPeers(int) []id.Signatory
	// NumPeers returns the total number of peers with associated network
	// addresses in the table.
	NumPeers() int

	// HandleExpired returns whether a signatory has expired. It checks whether
	// an Expiry exists for the signatory, and if it does, has it expired?
	// If found expired, it deletes the peer from the table
	HandleExpired(id.Signatory) bool
	// AddExpiry to the table with given duration if no existing expiry is found
	AddExpiry(id.Signatory, time.Duration)
	// DeleteExpiry from the table
	DeleteExpiry(id.Signatory)

	// AddSubnet to the table. This returns a subnet hash that can be used to
	// read/delete the subnet. It is the merkle root hash of the peers in the
	// subnet.
	AddSubnet([]id.Signatory) id.Hash
	// DeleteSubnet from the table. If the subnet was in the table, then the
	// peers are returned.
	DeleteSubnet(id.Hash)
	// Subnet returns the peers from the table.
	Subnet(id.Hash) []id.Signatory
}

A Table is responsible for keeping tack of peers, their network addresses, and the subnet to which they belong.