@waku/rln/bundle/packages/utils/dist/common/sharding/index.js

RLN (Rate Limiting Nullifier) implementation for Waku

import { sha256 } from '../../../../../node_modules/@noble/hashes/esm/sha256.js';
import '../../../../interfaces/dist/protocols.js';
import '../../../../interfaces/dist/connection_manager.js';
import { DEFAULT_CLUSTER_ID } from '../../../../interfaces/dist/constants.js';
import '../../../../interfaces/dist/health_status.js';
import { concat, utf8ToBytes } from '../../bytes/index.js';

const singleShardInfoToPubsubTopic = (shardInfo) => {
    if (shardInfo.shard === undefined)
        throw new Error("Invalid shard");
    return `/waku/2/rs/${shardInfo.clusterId ?? DEFAULT_CLUSTER_ID}/${shardInfo.shard}`;
};
/**
 * Given a string, will throw an error if it is not formatted as a valid content topic for autosharding based on https://rfc.vac.dev/spec/51/
 * @param contentTopic String to validate
 * @returns Object with each content topic field as an attribute
 */
function ensureValidContentTopic(contentTopic) {
    const parts = contentTopic.split("/");
    if (parts.length < 5 || parts.length > 6) {
        throw Error("Content topic format is invalid");
    }
    // Validate generation field if present
    let generation = 0;
    if (parts.length == 6) {
        generation = parseInt(parts[1]);
        if (isNaN(generation)) {
            throw new Error("Invalid generation field in content topic");
        }
        if (generation > 0) {
            throw new Error("Generation greater than 0 is not supported");
        }
    }
    // Validate remaining fields
    const fields = parts.splice(-4);
    // Validate application field
    if (fields[0].length == 0) {
        throw new Error("Application field cannot be empty");
    }
    // Validate version field
    if (fields[1].length == 0) {
        throw new Error("Version field cannot be empty");
    }
    // Validate topic name field
    if (fields[2].length == 0) {
        throw new Error("Topic name field cannot be empty");
    }
    // Validate encoding field
    if (fields[3].length == 0) {
        throw new Error("Encoding field cannot be empty");
    }
    return {
        generation,
        application: fields[0],
        version: fields[1],
        topicName: fields[2],
        encoding: fields[3]
    };
}
/**
 * Given a string, determines which autoshard index to use for its pubsub topic.
 * Based on the algorithm described in the RFC: https://rfc.vac.dev/spec/51//#algorithm
 */
function contentTopicToShardIndex(contentTopic, networkShards = 8) {
    const { application, version } = ensureValidContentTopic(contentTopic);
    const digest = sha256(concat([utf8ToBytes(application), utf8ToBytes(version)]));
    const dataview = new DataView(digest.buffer.slice(-8));
    return Number(dataview.getBigUint64(0, false) % BigInt(networkShards));
}
function contentTopicToPubsubTopic(contentTopic, clusterId = DEFAULT_CLUSTER_ID, networkShards = 8) {
    if (!contentTopic) {
        throw Error("Content topic must be specified");
    }
    const shardIndex = contentTopicToShardIndex(contentTopic, networkShards);
    return `/waku/2/rs/${clusterId}/${shardIndex}`;
}
/**
 * Used when creating encoders/decoders to determine which pubsub topic to use
 */
function determinePubsubTopic(contentTopic, 
// TODO: make it accept ShardInfo https://github.com/waku-org/js-waku/issues/2086
pubsubTopicShardInfo) {
    if (typeof pubsubTopicShardInfo == "string") {
        return pubsubTopicShardInfo;
    }
    return pubsubTopicShardInfo?.shard !== undefined
        ? singleShardInfoToPubsubTopic(pubsubTopicShardInfo)
        : contentTopicToPubsubTopic(contentTopic, pubsubTopicShardInfo?.clusterId ?? DEFAULT_CLUSTER_ID);
}

export { contentTopicToPubsubTopic, contentTopicToShardIndex, determinePubsubTopic, ensureValidContentTopic, singleShardInfoToPubsubTopic };