JavaScript Implementation of the IPLD Format MerkleDAG Node in Protobuf. In addition to the IPLD Format methods, this module also provides an API for creating the nodes and manipulating them (adding and removing links, etc).
- Install
- Usage
- API
- DAGNode functions
- DAGNode instance methods and properties
- DAGLink functions
- DAGLink instance methods and properties
- [IPLD Format Specifics - Local (node/block scope) resolver](#ipld-format-specificshttpsgithubcomipldinterface-ipld-format---local-nodeblock-scope-resolver)
- [IPLD Format Specifics - util](#ipld-format-specificshttpsgithubcomipldinterface-ipld-format---util)
dagPB.util.cid
dagPB.util.serialize
dagPB.util.deserialize
- Maintainers
- Contribute
- License
> npm install ipld-dag-pb --save
const dagPB = require('ipld-dag-pb')
dagPB.DAGNode.create // create a DAGNode
dagPB.DAGNode.clone // clone a DAGNode
dagPB.DAGNode.addLink // add a Link to a DAGNode, creating a new one
dagPB.DAGNode.rmLink // remove a Link to a DAGNode, creating a new one
dagPB.DAGLink.create // create a DAGLink
// IPLD Format specifics
dagPB.resolver
dagPB.util
DAGNode.create(new Buffer('some data'), (err, node1) => {
if (err) {
throw error
}
// node1 is your DAGNode instance.
})
DAGNode.create('some data', (err, node2) => {
// node2 will have the same data as node1.
})
const link = {
name: 'I am a link',
multihash: 'QmHash..',
size: 42
}
DAGNode.addLink(node, link, (err, nodeA) => {
if (err) {
throw err
}
// node - DAGNode instance with the link
console.log('with link', nodeA.toJSON())
DAGNode.rmLink(nodeA, 'I am a link', (err, nodeB) => {
if (err) {
throw err
}
// node - DAGNode instance without the link, equal to just node
console.log('without link', nodeB.toJSON())
})
})
DAGNodes are immutable objects, in order to manipulate them you have to follow a function approach of applying function and getting new instances of the given DAGNode.
You can incude it in your project with:
const dagPB = require('ipld-dag-pb')
const DAGNode = dagPB.DAGNode
data
- type: Bufferlinks
- type: Array of DAGLink instances or Array of DAGLink instances in its json format (link.toJSON)hashAlg
- type: Stringcallback
- type: function with signaturefunction (err, node) {}
Create a DAGNode.
DAGNode.create('data', links, (err, dagNode) => {
// ...
})
links can be a single or an array of DAGLinks instances or objects with the following pattern
{
name: '<some name>',
hash: '<some multihash>', // can also be `multihash: <some multihash>`
size: <sizeInBytes>
}
node
- type: DAGNodelink
- type: DAGLink or DAGLink in its json formatcallback
- type: function with signaturefunction (err, node) {}
Creates a link on node A to node B by using node B to get its multihash. Returns a new instance of DAGNode without modifying the old one.
Creates a new DAGNode instance with the union of node.links plus the new link.
link
can be:
- DAGLink instance
- DAGNode instance
- Object with the following properties:
{
name: '<some string>', // optional
size: <size in bytes>,
multihash: <multihash> // can be a String multihash or multihash buffer
}
node
- type: DAGNodenameOrMultihash
- type: String or multihash buffercallback
- type: function with signaturefunction (err, node) {}
Removes a link from the node by name. Returns a new instance of DAGNode without modifying the old one.
DAGNode.rmLink(node, 'Link1' (err, dagNode) => ...)
node
- type: DAGNodecallback
- type: function with signaturefunction (err, node) {}
Creates a clone of the DAGNode instance passed
DAGNode.clone(node, (err, nodeClone) => {})
You have the following methods and properties available in every DAGNode instance.
An array of DAGLinks
Size of the node, in bytes
Following the same pattern as DAGNode functions
above, DAGLink also offers a function for its creation.
You can incude it in your project with:
const dagPB = require('ipld-dag-pb')
const DAGLink = dagPB.DAGLink
DAGLink.create(
'link-to-file', // name of the link (can be empty)
10, // size in bytes
'QmSomeHash...', // can be multihash buffer or string
(err, link) => {
if (err) {
throw err
}
// link is a DAGLink instance
})
Note: DAGLinks are simpler objects and can be instantiated directly:
const link = new DAGLink(name, size, multihash)
IPLD Format Specifics - Local (node/block scope) resolver
See: https://github.com/ipld/interface-ipld-format#local-resolver-methods
IPLD Format Specifics - util
See: https://github.com/ipld/interface-ipld-format#ipld-format-utils
Please contribute! Look at the issues!
Check out our contributing document for more information on how we work, and about contributing in general. Please be aware that all interactions related to IPLD are subject to the IPFS Code of Conduct.
Small note: If editing the README, please conform to the standard-readme specification.
ISC © 2016 Protocol Labs Inc.