downloader

Documentation

Overview

Package downloader contains the manual full chain synchronisation.

Package downloader contains the manual full chain synchronisation.

Index

• Variables
• type BlockChain
• type DoneEvent
• type Downloader
  • func New(mode SyncMode, stateDb ethdb.Database, mux *event.TypeMux, chain BlockChain, ...) *Downloader
  • func (d *Downloader) Cancel()
  • func (d *Downloader) DeliverHeaders(id string, headers []*types.Header) (err error)
  • func (d *Downloader) RegisterLightPeer(id string, version int, peer LightPeer) error
  • func (d *Downloader) RegisterPeer(id string, version int, peer Peer) error
  • func (d *Downloader) Synchronise(id string, head common.Hash, td *big.Int, mode SyncMode) error
  • func (d *Downloader) Synchronising() bool
  • func (d *Downloader) Terminate()
  • func (d *Downloader) UnregisterPeer(id string) error
• type FailedEvent
• type LightPeer
• type Peer
• type StartEvent
• type SyncMode
  • func (mode SyncMode) IsValid() bool
  • func (mode SyncMode) MarshalText() ([]byte, error)
  • func (mode SyncMode) String() string
  • func (mode *SyncMode) UnmarshalText(text []byte) error

Variables

var (
	MaxHashFetch    = 512 // Amount of hashes to be fetched per retrieval request
	MaxBlockFetch   = 128 // Amount of blocks to be fetched per retrieval request
	MaxHeaderFetch  = 192 // Amount of block headers to be fetched per retrieval request
	MaxSkeletonSize = 128 // Number of header fetches to need for a skeleton assembly
	MaxBodyFetch    = 128 // Amount of block bodies to be fetched per retrieval request
	MaxReceiptFetch = 256 // Amount of transaction receipts to allow fetching per request
	MaxStateFetch   = 384 // Amount of node state values to allow fetching per request

	MaxForkAncestry = 3 * params.EpochDuration // Maximum chain reorganisation

)

Types

type BlockChain

type BlockChain interface {
	// HasHeader verifies a header's presence in the local chain.
	HasHeader(common.Hash, uint64) bool

	// GetHeaderByHash retrieves a header from the local chain.
	GetHeaderByHash(common.Hash) *types.Header

	// CurrentHeader retrieves the head header from the local chain.
	CurrentHeader() *types.Header

	// GetTd returns the total difficulty of a local block.
	GetTd(common.Hash, uint64) *big.Int

	// InsertHeaderChain inserts a batch of headers into the local chain.
	InsertHeaderChain([]*types.Header, int) (int, error)
}

BlockChain encapsulates functions required to synchronise a light chain.

type DoneEvent

type DoneEvent struct{}

type Downloader

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

func New

func New(mode SyncMode, stateDb ethdb.Database, mux *event.TypeMux, chain BlockChain, dropPeer peerDropFn) *Downloader

New creates a new downloader to fetch hashes and blocks from remote peers.

func (*Downloader) Cancel

func (d *Downloader) Cancel()

Cancel cancels all of the operations and resets the queue. It returns true if the cancel operation was completed.

func (*Downloader) DeliverHeaders

func (d *Downloader) DeliverHeaders(id string, headers []*types.Header) (err error)

DeliverHeaders injects a new batch of block headers received from a remote node into the download schedule.

func (*Downloader) RegisterLightPeer

func (d *Downloader) RegisterLightPeer(id string, version int, peer LightPeer) error

RegisterLightPeer injects a light client peer, wrapping it so it appears as a regular peer.

func (*Downloader) RegisterPeer

func (d *Downloader) RegisterPeer(id string, version int, peer Peer) error

RegisterPeer injects a new download peer into the set of block source to be used for fetching hashes and blocks from.

func (*Downloader) Synchronise

func (d *Downloader) Synchronise(id string, head common.Hash, td *big.Int, mode SyncMode) error

Synchronise tries to sync up our local block chain with a remote peer, both adding various sanity checks as well as wrapping it with various log entries.

func (*Downloader) Synchronising

func (d *Downloader) Synchronising() bool

Synchronising returns whether the downloader is currently retrieving blocks.

func (*Downloader) Terminate

func (d *Downloader) Terminate()

Terminate interrupts the downloader, canceling all pending operations. The downloader cannot be reused after calling Terminate.

func (*Downloader) UnregisterPeer

func (d *Downloader) UnregisterPeer(id string) error

UnregisterPeer remove a peer from the known list, preventing any action from the specified peer. An effort is also made to return any pending fetches into the queue.

type FailedEvent

type FailedEvent struct{ Err error }

type LightPeer

type LightPeer interface {
	Head() (common.Hash, *big.Int)
	RequestHeadersByHash(common.Hash, int, int, bool) error
	RequestHeadersByNumber(uint64, int, int, bool) error
}

LightPeer encapsulates the methods required to synchronise with a remote light peer.

type Peer

type Peer interface {
	LightPeer
}

Peer encapsulates the methods required to synchronise with a remote full peer.

type StartEvent

type StartEvent struct{}

type SyncMode

type SyncMode int

SyncMode represents the synchronisation mode of the downloader.

const (
	FullSync  SyncMode = iota // Synchronise the entire blockchain history from full blocks
	FastSync                  // Quickly download the headers, full sync only at the chain head
	LightSync                 // Download only the headers and terminate afterwards
)

func (SyncMode) IsValid

func (mode SyncMode) IsValid() bool

func (SyncMode) MarshalText

func (mode SyncMode) MarshalText() ([]byte, error)

func (SyncMode) String

func (mode SyncMode) String() string

String implements the stringer interface.

func (*SyncMode) UnmarshalText

func (mode *SyncMode) UnmarshalText(text []byte) error