bitswap

README

go-bitswap

An implementation of the bitswap protocol in go!

Table of Contents

• Background
• Usage
• Implementation
• Contribute
• License

Background

Bitswap is the data trading module for ipfs. It manages requesting and sending blocks to and from other peers in the network. Bitswap has two main jobs:

• to acquire blocks requested by the client from the network
• to judiciously send blocks in its possession to other peers who want them

Bitswap is a message based protocol, as opposed to request-response. All messages contain wantlists or blocks.

A node sends a wantlist to tell peers which blocks it wants. When a node receives a wantlist it should check which blocks it has from the wantlist, and consider sending the matching blocks to the requestor.

When a node receives blocks that it asked for, the node should send out a notification called a 'Cancel' to tell its peers that the node no longer wants those blocks.

go-bitswap provides an implementation of the Bitswap protocol in go.

Learn more about how Bitswap works

Usage

Initializing a Bitswap Exchange

import (
  "context"
  bitswap "github.com/ipfs/boxo/bitswap"
  bsnet "github.com/ipfs/boxo/bitswap/network"
  blockstore "github.com/ipfs/go-ipfs-blockstore"
  "github.com/libp2p/go-libp2p-core/routing"
  "github.com/libp2p/go-libp2p-core/host"
)

var ctx context.Context
var host host.Host
var router routing.ContentRouting
var bstore blockstore.Blockstore

network := bsnet.NewFromIpfsHost(host, router)
exchange := bitswap.New(ctx, network, bstore)

Parameter Notes:

1. ctx is just the parent context for all of Bitswap
2. network is a network abstraction provided to Bitswap on top of libp2p & content routing.
3. bstore is an IPFS blockstore

Get A Block Synchronously

var c cid.Cid
var ctx context.Context
var exchange bitswap.Bitswap

block, err := exchange.GetBlock(ctx, c)

Parameter Notes:

1. ctx is the context for this request, which can be cancelled to cancel the request
2. c is the content ID of the block you're requesting

Get Several Blocks Asynchronously

var cids []cid.Cid
var ctx context.Context
var exchange bitswap.Bitswap

blockChannel, err := exchange.GetBlocks(ctx, cids)

Parameter Notes:

1. ctx is the context for this request, which can be cancelled to cancel the request
2. cids is a slice of content IDs for the blocks you're requesting

Get Related Blocks Faster With Sessions

In IPFS, content blocks are often connected to each other through a MerkleDAG. If you know ahead of time that block requests are related, Bitswap can make several optimizations internally in how it requests those blocks in order to get them faster. Bitswap provides a mechanism called a Bitswap Session to manage a series of block requests as part of a single higher level operation. You should initialize a Bitswap Session any time you intend to make a series of block requests that are related -- and whose responses are likely to come from the same peers.

var ctx context.Context
var cids []cids.cid
var exchange bitswap.Bitswap

session := exchange.NewSession(ctx)
blocksChannel, err := session.GetBlocks(ctx, cids)
// later
var relatedCids []cids.cid
relatedBlocksChannel, err := session.GetBlocks(ctx, relatedCids)

Note that NewSession returns an interface with GetBlock and GetBlocks methods that have the same signature as the overall Bitswap exchange.

Tell bitswap a new block was added to the local datastore

var blk blocks.Block
var exchange bitswap.Bitswap

err := exchange.HasBlock(blk)

Documentation

Index

• Variables
• type Bitswap
  • func New(ctx context.Context, net network.BitSwapNetwork, bstore blockstore.Blockstore, ...) *Bitswap
  • func (bs *Bitswap) Close() error
  • func (bs *Bitswap) NotifyNewBlocks(ctx context.Context, blks ...blocks.Block) error
  • func (bs *Bitswap) PeerConnected(p peer.ID)
  • func (bs *Bitswap) PeerDisconnected(p peer.ID)
  • func (bs *Bitswap) ReceiveError(err error)
  • func (bs *Bitswap) ReceiveMessage(ctx context.Context, p peer.ID, incoming message.BitSwapMessage)
  • func (bs *Bitswap) Stat() (*Stat, error)
  • func (bs *Bitswap) WantlistForPeer(p peer.ID) []cid.Cid
• type Option
  • func EngineBlockstoreWorkerCount(count int) Option
  • func EngineTaskWorkerCount(count int) Option
  • func MaxCidSize(n uint) Option
  • func MaxOutstandingBytesPerPeer(count int) Option
  • func MaxQueuedWantlistEntriesPerPeer(count uint) Option
  • func ProvideEnabled(enabled bool) Option
  • func ProviderSearchDelay(newProvSearchDelay time.Duration) Option
  • func RebroadcastDelay(newRebroadcastDelay delay.D) Option
  • func SetSendDontHaves(send bool) Option
  • func SetSimulateDontHavesOnTimeout(send bool) Option
  • func TaskWorkerCount(count int) Option
  • func WithBlockReceivedNotifier(brn client.BlockReceivedNotifier) Option
  • func WithPeerBlockRequestFilter(pbrf server.PeerBlockRequestFilter) Option
  • func WithPeerLedger(peerLedger server.PeerLedger) Option
  • func WithScoreLedger(scoreLedger server.ScoreLedger) Option
  • func WithTargetMessageSize(tms int) Option
  • func WithTaskComparator(comparator server.TaskComparator) Option
  • func WithTracer(tap tracer.Tracer) Option
  • func WithoutDuplicatedBlockStats() Option
• type PeerBlockRequestFilter
• type Stat
• type TaskComparator
• type TaskInfo
• type Tracer

Variables

var (
	HasBlockBufferSize = defaults.HasBlockBufferSize
)

Types

type Bitswap

type Bitswap struct {
	*client.Client
	*server.Server
	// contains filtered or unexported fields
}

func New

func New(ctx context.Context, net network.BitSwapNetwork, bstore blockstore.Blockstore, options ...Option) *Bitswap

func (*Bitswap) Close

func (bs *Bitswap) Close() error

func (*Bitswap) NotifyNewBlocks

func (bs *Bitswap) NotifyNewBlocks(ctx context.Context, blks ...blocks.Block) error

func (*Bitswap) PeerConnected

func (bs *Bitswap) PeerConnected(p peer.ID)

func (*Bitswap) PeerDisconnected

func (bs *Bitswap) PeerDisconnected(p peer.ID)

func (*Bitswap) ReceiveError

func (bs *Bitswap) ReceiveError(err error)

func (*Bitswap) ReceiveMessage

func (bs *Bitswap) ReceiveMessage(ctx context.Context, p peer.ID, incoming message.BitSwapMessage)

func (*Bitswap) Stat

func (bs *Bitswap) Stat() (*Stat, error)

func (*Bitswap) WantlistForPeer

func (bs *Bitswap) WantlistForPeer(p peer.ID) []cid.Cid

type Option

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

Option is interface{} of server.Option or client.Option or func(*Bitswap) wrapped in a struct to gain strong type checking.

func EngineBlockstoreWorkerCount

func EngineBlockstoreWorkerCount(count int) Option

func EngineTaskWorkerCount

func EngineTaskWorkerCount(count int) Option

func MaxCidSize

func MaxCidSize(n uint) Option

MaxCidSize only affects the server. If it is 0 no limit is applied.

func MaxOutstandingBytesPerPeer

func MaxOutstandingBytesPerPeer(count int) Option

func MaxQueuedWantlistEntriesPerPeer

func MaxQueuedWantlistEntriesPerPeer(count uint) Option

func ProvideEnabled

func ProvideEnabled(enabled bool) Option

func ProviderSearchDelay

func ProviderSearchDelay(newProvSearchDelay time.Duration) Option

func RebroadcastDelay

func RebroadcastDelay(newRebroadcastDelay delay.D) Option

func SetSendDontHaves

func SetSendDontHaves(send bool) Option

func SetSimulateDontHavesOnTimeout

func SetSimulateDontHavesOnTimeout(send bool) Option

func TaskWorkerCount

func TaskWorkerCount(count int) Option

func WithBlockReceivedNotifier

func WithBlockReceivedNotifier(brn client.BlockReceivedNotifier) Option

func WithPeerBlockRequestFilter

func WithPeerBlockRequestFilter(pbrf server.PeerBlockRequestFilter) Option

func WithPeerLedger

func WithPeerLedger(peerLedger server.PeerLedger) Option

func WithScoreLedger

func WithScoreLedger(scoreLedger server.ScoreLedger) Option

func WithTargetMessageSize

func WithTargetMessageSize(tms int) Option

func WithTaskComparator

func WithTaskComparator(comparator server.TaskComparator) Option

func WithTracer

func WithTracer(tap tracer.Tracer) Option

func WithoutDuplicatedBlockStats

func WithoutDuplicatedBlockStats() Option

type PeerBlockRequestFilter

type PeerBlockRequestFilter = server.PeerBlockRequestFilter

DEPRECATED

type Stat

type Stat struct {
	Wantlist         []cid.Cid
	Peers            []string
	BlocksReceived   uint64
	DataReceived     uint64
	DupBlksReceived  uint64
	DupDataReceived  uint64
	MessagesReceived uint64
	BlocksSent       uint64
	DataSent         uint64
	ProvideBufLen    int
}

type TaskComparator

type TaskComparator = server.TaskComparator

DEPRECATED

type TaskInfo

type TaskInfo = server.TaskInfo

DEPRECATED

type Tracer

type Tracer = tracer.Tracer

DEPRECATED