js-ipfs-merkle-dag

JavaScript Implementation of the DAGService and DAGNode data structure

Table of Contents

• Install
• Architecture
• Usage
• API
• Contribute
• License

Install

$ npm i ipfs-merkle-dag

Architecture

┌────────────────────┐
│   DAGService       │
└────────────────────┘
           │
           ▼
┌────────────────────┐
│   BlockService     │
└────────────────────┘

DAGService - The DAGService offers an interface to interact directly with a MerkleDAG object (composed by one or more DAGNodes that are linked), using the BlockService to store and fetch the DAGNodes as it needs them

BlockService - The BlockService uses IPFS Repo as the local datastore for blocks and an IPFS Exchange compliant implementation to fetch blocks from the network.

A DAGNode and DAGLink are data structures made available on this module.

Usage

const ipfsMDAG = require('ipfs-merkle-dag')

// then, to access each of the components
ipfsMDAG.DAGService
ipfsMDAG.DAGNode
ipfsMDAG.DAGLink

API

DAGNode Class

Create a new DAGNode

var node = new ipfsMDAG.DAGNode([<data>, <[links]>])

addNodeLink

creates a link on node A to node B by using node B to get its multihash

addRawLink

creates a link on node A to node B by using directly node B multihash

updateNodeLink

updates a link on the node. caution this method returns a copy of the MerkleDAG node

removeNodeLink

removes a link from the node by name

removeNodeLinkByHash

removes a link from the node by the hash of the linked node

copy

creates a copy of the MerkleDAG Node

size

(property) size of the node, in bytes

links

(property) an array of DAGLinks belonging to the node

multihash

returns the multihash (default: sha2-256)

marshal

returns a protobuf serialized version, compatible with go-ipfs MerkleDAG

unMarshal

deserializes a node encoded using protobuf

getPBNode

used internally

makeLink

used internally

DAGLink Class

Create a new DAGLink

var link = new ipfsMDAG.DAGLink(<name>, <size>, <hash>)

DAGService

put

stores the node

putStream

stores nodes using a writable pull-stream

get

fetches a node by its multihash

getStream

fetches a node as a pull-stream

getRecursive

fetches a node and all of its links (if possible)

getRecursiveStream

fetches a node and all of its links (if possible) as pull-stream

remove

deletes a node

License

MIT © IPFS