$ npm install @ipld/dag-cbor
JS implementation of DAG-CBOR
$ npm i @ipld/dag-cbor
This is the new interface meant for use by itself or with multiformats and
@ipld/block. It is not used by js-ipld-format which is currently
used in IPFS. That library is here.
Usage:
import { encode, decode } from '@ipld/dag-cbor'
import { CID } from 'multiformats'
const obj = {
x: 1,
/* CID instances are encoded as links */
y: [2, 3, CID.parse('QmaozNR7DZHQK1ZcU9p7QdrshMvXqWK6gpu5rmrkPdT3L4')],
z: {
a: CID.parse('QmaozNR7DZHQK1ZcU9p7QdrshMvXqWK6gpu5rmrkPdT3L4'),
b: null,
c: 'string'
}
}
let data = encode(obj)
let decoded = decode(data)
decoded.y[0] // 2
CID.asCID(decoded.z.a) // cid instance
// encode/decode options are exported for use with cborg's encodedLength and decodeFirst
import { encodeOptions, decodeOptions } from '@ipld/dag-cbor'
import { encodedLength } from 'cborg/length'
import { decodeFirst } from 'cborg'
// dag-cbor encoded length of obj in bytes
const byteLength = encodedLength(obj, encodeOptions)
byteLength // 104
// concatenate two dag-cbor encoded obj
const concatenatedData = new Uint8Array(data.length * 2)
concatenatedData.set(data)
concatenatedData.set(data, data.length)
// returns dag-cbor decoded obj at the beginning of the buffer as well as the remaining bytes
const [first, remainder] = decodeFirst(concatenatedData, decodeOptions)
assert.deepStrictEqual(first, obj)
assert.deepStrictEqual(remainder, data)
The dag-cbor specification is in the IPLD specs repo.
Licensed under either of
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.