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Merged
rosarp merged 1 commit into from
Dec 17, 2025
Merged

refactored cid dag metadata in examples #151

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2 changes: 1 addition & 1 deletion examples/api.js
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Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
import { cidFromBytes } from "./common.js";
import { cidFromBytes } from "./cid_dag_metadata.js";
import { Binary } from '@polkadot-api/substrate-bindings';

export async function authorizeAccount(typedApi, sudoSigner, who, transactions, bytes) {
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3 changes: 2 additions & 1 deletion examples/authorize_and_store.js
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Expand Up @@ -2,7 +2,8 @@ import { ApiPromise, WsProvider } from '@polkadot/api';
import { Keyring } from '@polkadot/keyring';
import { cryptoWaitReady } from '@polkadot/util-crypto';
import { create } from 'ipfs-http-client';
import { waitForNewBlock, cidFromBytes } from './common.js';
import { waitForNewBlock } from './common.js';
import { cidFromBytes } from "./cid_dag_metadata.js";

async function authorizeAccount(api, pair, who, transactions, bytes) {
const tx = api.tx.transactionStorage.authorizeAccount(who, transactions, bytes);
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3 changes: 2 additions & 1 deletion examples/authorize_and_store_papi.js
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Expand Up @@ -3,7 +3,8 @@ import { createClient } from 'polkadot-api';
import { getWsProvider } from 'polkadot-api/ws-provider';
import { cryptoWaitReady } from '@polkadot/util-crypto';
import { authorizeAccount, fetchCid, store} from './api.js';
import { setupKeyringAndSigners, cidFromBytes } from './common.js';
import { setupKeyringAndSigners } from './common.js';
import { cidFromBytes } from "./cid_dag_metadata.js";
import { bulletin } from './.papi/descriptors/dist/index.mjs';

const NODE_WS = 'ws://localhost:10000';
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3 changes: 2 additions & 1 deletion examples/authorize_and_store_papi_smoldot.js
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Expand Up @@ -5,7 +5,8 @@ import { createClient } from 'polkadot-api';
import { getSmProvider } from 'polkadot-api/sm-provider';
import { cryptoWaitReady } from '@polkadot/util-crypto';
import { authorizeAccount, fetchCid, store } from './api.js';
import { setupKeyringAndSigners, cidFromBytes } from './common.js';
import { setupKeyringAndSigners } from './common.js';
import { cidFromBytes } from "./cid_dag_metadata.js";
import { bulletin } from './.papi/descriptors/dist/index.mjs';

// Constants
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78 changes: 78 additions & 0 deletions examples/cid_dag_metadata.js
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@@ -0,0 +1,78 @@
import { blake2AsU8a } from '@polkadot/util-crypto';
import * as multihash from 'multiformats/hashes/digest';
import { CID } from 'multiformats/cid';
import * as dagPB from '@ipld/dag-pb';
import { UnixFS } from 'ipfs-unixfs';

/**
* Build a UnixFS DAG-PB file node from raw chunks.
*
* (By default with SHA2 multihash)
*/
export async function buildUnixFSDagPB(chunks, mhCode = 0x12) {
if (!chunks?.length) {
throw new Error('❌ buildUnixFSDag: chunks[] is empty')
}

// UnixFS blockSizes = sizes of child blocks
const blockSizes = chunks.map(c => c.len)

console.log(`🧩 Building UnixFS DAG from chunks:
• totalChunks: ${chunks.length}
• blockSizes: ${blockSizes.join(', ')}`)

// Build UnixFS file metadata (no inline data here)
const fileData = new UnixFS({
type: 'file',
blockSizes
})

// DAG-PB node: our file with chunk links
const dagNode = dagPB.prepare({
Data: fileData.marshal(),
Links: chunks.map(c => ({
Name: '',
Tsize: c.len,
Hash: c.cid
}))
})

// Encode DAG-PB
const dagBytes = dagPB.encode(dagNode)

// Hash DAG to produce CIDv1
const rootCid = await cidFromBytes(dagBytes, dagPB.code, mhCode)

console.log(`✅ DAG root CID: ${rootCid.toString()}`)

return { rootCid, dagBytes }
}

/**
* Create CID for data.
* Default to `0x55 (raw)` with blake2b_256 hash.
*
* 0xb220:
* - 0xb2 = the multihash algorithm family for BLAKE2b
* - 0x20 = the digest length in bytes (32 bytes = 256 bits)
*
* See: https://github.com/multiformats/multicodec/blob/master/table.csv
*/
export async function cidFromBytes(bytes, cidCodec = 0x55, mhCode = 0xb220) {
console.log(`[CID]: Using cidCodec: ${cidCodec} and mhCode: ${mhCode}`);
let mh;
switch (mhCode) {
case 0xb220: // blake2b-256
mh = multihash.create(mhCode, blake2AsU8a(bytes));
break;

default:
throw new Error("Unhandled multihash code: " + mhCode)
}
return CID.createV1(cidCodec, mh)
}

export function convertCid(cid, cidCodec) {
const mh = cid.multihash;
return CID.createV1(cidCodec, mh);
}
101 changes: 23 additions & 78 deletions examples/common.js
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@@ -1,10 +1,5 @@
import { blake2AsU8a } from '@polkadot/util-crypto'
import * as multihash from 'multiformats/hashes/digest'
import { CID } from 'multiformats/cid'
import { Keyring } from '@polkadot/keyring';
import { getPolkadotSigner } from '@polkadot-api/signer';
import * as dagPB from '@ipld/dag-pb'
import { UnixFS } from 'ipfs-unixfs'
import { createCanvas } from "canvas";
import fs from "fs";
import assert from "assert";
Expand All @@ -15,35 +10,6 @@ export async function waitForNewBlock() {
return new Promise(resolve => setTimeout(resolve, 7000))
}

/**
* Create CID for data.
* Default to `0x55 (raw)` with blake2b_256 hash.
*
* 0xb220:
* - 0xb2 = the multihash algorithm family for BLAKE2b
* - 0x20 = the digest length in bytes (32 bytes = 256 bits)
*
* See: https://github.com/multiformats/multicodec/blob/master/table.csv
*/
export async function cidFromBytes(bytes, cidCodec = 0x55, mhCode = 0xb220) {
console.log(`[CID]: Using cidCodec: ${cidCodec} and mhCode: ${mhCode}`);
let mh;
switch (mhCode) {
case 0xb220: // blake2b-256
mh = multihash.create(mhCode, blake2AsU8a(bytes));
break;

default:
throw new Error("Unhandled multihash code: " + mhCode)
}
return CID.createV1(cidCodec, mh)
}

export function convertCid(cid, cidCodec) {
const mh = cid.multihash;
return CID.createV1(cidCodec, mh);
}

/**
* Creates a PAPI-compatible signer from a Keyring account
*/
Expand All @@ -70,50 +36,6 @@ export function setupKeyringAndSigners(sudoSeed, accountSeed) {
};
}

/**
* Build a UnixFS DAG-PB file node from raw chunks.
*
* (By default with SHA2 multihash)
*/
export async function buildUnixFSDagPB(chunks, mhCode = 0x12) {
if (!chunks?.length) {
throw new Error('❌ buildUnixFSDag: chunks[] is empty')
}

// UnixFS blockSizes = sizes of child blocks
const blockSizes = chunks.map(c => c.len)

console.log(`🧩 Building UnixFS DAG from chunks:
• totalChunks: ${chunks.length}
• blockSizes: ${blockSizes.join(', ')}`)

// Build UnixFS file metadata (no inline data here)
const fileData = new UnixFS({
type: 'file',
blockSizes
})

// DAG-PB node: our file with chunk links
const dagNode = dagPB.prepare({
Data: fileData.marshal(),
Links: chunks.map(c => ({
Name: '',
Tsize: c.len,
Hash: c.cid
}))
})

// Encode DAG-PB
const dagBytes = dagPB.encode(dagNode)

// Hash DAG to produce CIDv1
const rootCid = await cidFromBytes(dagBytes, dagPB.code, mhCode)

console.log(`✅ DAG root CID: ${rootCid.toString()}`)

return { rootCid, dagBytes }
}

/**
* Generates (dynamic) images based on the input text.
*/
Expand Down Expand Up @@ -173,3 +95,26 @@ export function filesAreEqual(path1, path2) {
assert.deepStrictEqual(data1[i], data2[i])
}
}

export async function fileToDisk(outputPath, fullBuffer) {
await new Promise((resolve, reject) => {
const ws = fs.createWriteStream(outputPath);
ws.write(fullBuffer);
ws.end();
ws.on('finish', resolve);
ws.on('error', reject);
});
console.log(`💾 File saved to: ${outputPath}`);
}

export class NonceManager {
constructor(initialNonce) {
this.nonce = initialNonce; // BN instance from api.query.system.account
}

getAndIncrement() {
const current = this.nonce;
this.nonce = this.nonce.addn(1); // increment BN
return current;
}
}
26 changes: 2 additions & 24 deletions examples/store_chunked_data.js
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Expand Up @@ -7,8 +7,9 @@ import { create } from 'ipfs-http-client'
import * as dagPB from '@ipld/dag-pb'
import { TextDecoder } from 'util'
import assert from "assert";
import { waitForNewBlock, cidFromBytes, buildUnixFSDagPB, convertCid, generateTextImage, filesAreEqual } from './common.js'
import { waitForNewBlock, generateTextImage, filesAreEqual, fileToDisk, NonceManager } from './common.js'
import { fetchCid } from "./api.js";
import { buildUnixFSDagPB, cidFromBytes, convertCid } from "./cid_dag_metadata.js";

// ---- CONFIG ----
const WS_ENDPOINT = 'ws://127.0.0.1:10000' // Bulletin node
Expand Down Expand Up @@ -72,17 +73,6 @@ async function retrieveMetadata(ipfs, metadataCid) {
return metadataJson;
}

async function fileToDisk(outputPath, fullBuffer) {
await new Promise((resolve, reject) => {
const ws = fs.createWriteStream(outputPath);
ws.write(fullBuffer);
ws.end();
ws.on('finish', resolve);
ws.on('error', reject);
});
console.log(`💾 File saved to: ${outputPath}`);
}

/**
* Fetches all chunks listed in metdataJson, concatenates into a single file,
* and saves to disk (or returns as Buffer).
Expand Down Expand Up @@ -210,18 +200,6 @@ async function storeProof(api, sudoPair, pair, rootCID, dagFileBytes, nonceMgr,
return { rawDagCid }
}

class NonceManager {
constructor(initialNonce) {
this.nonce = initialNonce; // BN instance from api.query.system.account
}

getAndIncrement() {
const current = this.nonce;
this.nonce = this.nonce.addn(1); // increment BN
return current;
}
}

async function authorizeStorage(api, sudoPair, pair, nonceMgr) {
// Ensure enough quota.
const auth = await api.query.transactionStorage.authorizations({ "Account": pair.address});
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