forked from DECA/DECA-Protocol-FE
48 lines
1.4 KiB
JavaScript
48 lines
1.4 KiB
JavaScript
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/* eslint-env browser */
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import varint from 'varint'
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import { encode as cborEncode } from '@ipld/dag-cbor'
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/**
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* @param {import('multiformats').UnknownLink[]} roots
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* @returns {Uint8Array}
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*/
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function encodeHeader (roots) {
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const headerBytes = cborEncode({ version: 1, roots })
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const varintBytes = varint.encode(headerBytes.length)
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const header = new Uint8Array(varintBytes.length + headerBytes.length)
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header.set(varintBytes, 0)
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header.set(headerBytes, varintBytes.length)
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return header
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}
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/**
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* @param {import('@ipld/unixfs').Block} block
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* @returns {Uint8Array}
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*/
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function encodeBlock (block) {
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const varintBytes = varint.encode(block.cid.bytes.length + block.bytes.length)
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const bytes = new Uint8Array(varintBytes.length + block.cid.bytes.length + block.bytes.length)
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bytes.set(varintBytes)
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bytes.set(block.cid.bytes, varintBytes.length)
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bytes.set(block.bytes, varintBytes.length + block.cid.bytes.length)
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return bytes
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}
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/**
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* @extends {TransformStream<import('@ipld/unixfs').Block, Uint8Array>}
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*/
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export class CAREncoderStream extends TransformStream {
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/** @param {import('multiformats').UnknownLink[]} roots */
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constructor (roots = []) {
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super({
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start: (controller) => controller.enqueue(encodeHeader(roots)),
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transform: (block, controller) => {
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controller.enqueue(encodeBlock(block))
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this.finalBlock = block
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}
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})
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/** @type {import('@ipld/unixfs').Block?} */
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this.finalBlock = null
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}
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}
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