@dcdn/graphsync v0.2.5

GraphSync

JS implementation of the GraphSync v2 wire protocol.

Background

GraphSync is an IPFS data transfer protocol used across the IPFS and Web3 ecosystem for exchanging IPLD data. It is used by Filecoin for syncing the blockchain and transfering DAGified content in a trustless fashion.

Install

npm install @dcdn/graphsync

Usage

It is recommended to use with the WebTransport transport for best performance.

import {createLibp2p} from "libp2p";
import {Noise} from "@chainsafe/libp2p-noise";
import {webTransport} from "@libp2p/webtransport";
import {MemoryBlockstore} from "blockstore-core/memory";
import {GraphSync, unixfsPathSelector, getPeer} from "@dcdn/graphsync";

const blocks = new MemoryBlockstore();

const libp2p = await createLibp2p({
  transports: [webTransport()],
  connectionEncryption: [() => new Noise()],
});
await libp2p.start();
    
const exchange = new GraphSync(libp2p, blocks);

const provider = getPeer("/ip4/127.0.0.1/tcp/41505/ws/p2p/12D3KooWCYiNWNDoprcW74NVCEKaMhSbrfMvY4JEMfWrV1JamSsA");
libp2p.peerStore.addressBook.add(provider.id, provider.multiaddrs);
const [cid, selector] = unixfsPathSelector("bafyreiakhbtbs4tducqx5tcw36kdwodl6fdg43wnqaxmm64acckxhakeua/Cat.jpg");

const request = exchange.request(cid, selector);
request.open(provider.id);
// Save the blocks into the store;
await request.drain();