@hsuite/snapshots - Multi-Ledger Token Snapshot Management

📸 Comprehensive NestJS module for generating and managing token holder snapshots across multiple blockchain networks

Enterprise-grade snapshot management solution providing multi-ledger support, real-time progress tracking via WebSockets, IPFS integration, and plugin-based architecture for Hedera Hashgraph and Ripple/XRP Ledger networks with asynchronous processing.

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Table of Contents

• Quick Start

• Architecture

• API Reference

• Guides

• Examples

• Integration

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Quick Start

Installation

npm install @hsuite/snapshots

Basic Setup

import { SnapshotsModule } from '@hsuite/snapshots';

@Module({
  imports: [
    SnapshotsModule.forRootAsync({
      imports: [ConfigModule],
      useFactory: (config: ConfigService) => ({
        bull: {
          redis: {
            socket: {
              host: config.get('REDIS_HOST'),
              port: config.get('REDIS_PORT'),
            },
            password: config.get('REDIS_PASSWORD')
          }
        },
        jwt: {
          secret: config.get('JWT_SECRET'),
          signOptions: { expiresIn: '1h' }
        }
      }),
      inject: [ConfigService]
    })
  ]
})
export class AppModule {}

Simple Snapshot Generation

import { SnapshotsService } from '@hsuite/snapshots';
import { IAuth } from '@hsuite/auth-types';

@Injectable()
export class YourService {
  constructor(private snapshotsService: SnapshotsService) {}

  async generateSnapshot(tokenId: string, session: IAuth.ICredentials.IWeb3.IEntity) {
    const result = await this.snapshotsService.generateSnapshot(tokenId, session);
    return result; // Returns { jobId: string }
  }
}

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Architecture

Core Component Areas

📸 Snapshot Generation Engine

• Multi-Ledger Support - Hedera Hashgraph and Ripple/XRP Ledger compatibility

• Asynchronous Processing - Bull queues for reliable background processing

• Real-time Progress - WebSocket events for live snapshot generation updates

• Rate Limiting Compliance - Network-specific API rate limiting and batching

🔌 Plugin-Based Architecture

• Chain-Specific Handlers - Extensible plugin system for different blockchain networks

• Dynamic Configuration - Smart chain selection and configuration management

• Modular Design - Easy addition of new blockchain network support

• Standardized Interface - Consistent API across all supported networks

🌐 Real-time Communication

• WebSocket Gateway - Live progress tracking and event broadcasting

• JWT Authentication - Secure WebSocket connections and API access

• Event-Driven Updates - Comprehensive event system for all snapshot phases

• Client Reconnection - Automatic handling of connection recovery

💾 Storage & Distribution

• IPFS Integration - Decentralized storage for generated snapshots

• Data Persistence - Reliable snapshot data management

• Metadata Handling - Complete token metadata and holder information

• Export Formats - Multiple output formats for snapshot data

Module Structure

src/
├── index.ts                           # Main exports and public API
├── snapshots.module.ts                # NestJS module configuration
├── snapshots.service.ts               # Core snapshot generation service
├── snapshots.controller.ts            # REST API endpoints
├── snapshots.consumer.ts              # Bull queue processing
├── snapshots.gateway.ts               # WebSocket real-time updates
├── types/                             # TypeScript definitions
│   ├── interfaces/                    # Interface contracts
│   └── models/                        # Concrete implementations
└── ledgers/                           # Multi-chain support
    └── plugins/                       # Blockchain-specific handlers

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API Reference

Core Module

SnapshotsModule

• Purpose: Main module providing snapshot generation functionality

• Features: Redis queue configuration, JWT authentication, plugin registration

• Usage: Application-wide snapshot management integration

Core Services

SnapshotsService

• Purpose: Core service for initiating snapshot generation

• Methods: generateSnapshot(), getSnapshotStatus()

• Features: Token validation, job queue management, progress tracking

SnapshotsController

• Purpose: REST API controller for HTTP endpoints

• Endpoints: POST /snapshots/generate/:tokenId

• Features: Request validation, authentication, response formatting

WebSocket Events

Event Type	Description	Payload
snapshots_waiting	Job entered the waiting queue	{ jobId }
snapshots_active	Job started processing	{ jobId, jobName, snapshotId, status: 'activated', progress: 0 }
snapshots_progress	Progress update during generation	{ jobId, jobName, snapshotId, status: 'running', progress }
snapshots_completed	Job completed successfully	{ jobId, jobName, snapshotId, status: 'completed', progress: 100 }
snapshots_failed	Job failed with error	{ jobId, jobName, snapshotId, status: 'error', error }

Supported Networks

Network	Token Types	Features	Rate Limits
Hedera Hashgraph	Fungible, NFTs	Balance snapshots, metadata	25 accounts/batch, 1s delay
Ripple/XRP Ledger	Tokens	Balance snapshots	Framework ready

Plugin Interface

interface SnapshotLedgerPlugin {
  fetchAllTokenBalances(tokenId: string, job: Job): Promise<Array<any>>;
  validateToken(jobRequest: Snapshots.Queue.Upload.Request): void;
}

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Guides

Types System Documentation

Complete TypeScript definitions and data models for all snapshot operations. Understand the type system, interfaces, and models used throughout the snapshot generation process.

Multi-Chain Ledger Support

Plugin architecture guide for implementing new blockchain network support. Learn how to extend the system to support additional blockchains beyond Hedera and XRPL.

WebSocket Integration Guide

Learn how to implement real-time snapshot progress tracking in your applications. Set up WebSocket connections, handle progress events, and manage client-side state.

IPFS Storage Configuration

Set up decentralized storage for snapshot data with IPFS integration. Configure IPFS nodes, implement pinning strategies, and manage distributed storage for large datasets.

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Examples

Advanced Snapshot Service Implementation

import { SnapshotsService, ISnapshots } from '@hsuite/snapshots';
import { Injectable, Logger } from '@nestjs/common';
import { IAuth } from '@hsuite/auth-types';

@Injectable()
export class AdvancedSnapshotService {
  private readonly logger = new Logger(AdvancedSnapshotService.name);

  constructor(private readonly snapshotsService: SnapshotsService) {}

  async generateTokenSnapshot(
    tokenId: string, 
    session: IAuth.ICredentials.IWeb3.IEntity,
    options?: SnapshotGenerationOptions
  ) {
    try {
      // Validate token format based on chain
      this.validateTokenFormat(tokenId);

      // Log snapshot request
      this.logger.log(`Generating snapshot for token ${tokenId} by user ${session.walletId}`);

      // Generate snapshot with monitoring
      const result = await this.snapshotsService.generateSnapshot(tokenId, session);

      // Set up progress monitoring
      if (options?.monitorProgress) {
        await this.setupProgressMonitoring(result.jobId, options.progressCallback);
      }

      return {
        success: true,
        jobId: result.jobId,
        estimatedTime: this.estimateCompletionTime(tokenId),
        supportedFormats: ['json', 'csv'],
        websocketChannel: 'snapshots_events'
      };
    } catch (error) {
      this.logger.error(`Snapshot generation failed: ${error.message}`);
      throw new Error(`Failed to generate snapshot: ${error.message}`);
    }
  }

  async getSnapshotHistory(
    session: IAuth.ICredentials.IWeb3.IEntity,
    limit: number = 10
  ) {
    try {
      const history = await this.getSnapshotsByUser(session.walletId, limit);
      
      return {
        success: true,
        snapshots: history.map(snapshot => ({
          jobId: snapshot.jobId,
          tokenId: snapshot.tokenId,
          status: snapshot.status,
          progress: snapshot.progress,
          createdAt: snapshot.createdAt,
          completedAt: snapshot.completedAt,
          holderCount: snapshot.holderCount,
          ipfsCid: snapshot.ipfsCid
        })),
        totalCount: history.length
      };
    } catch (error) {
      throw new Error(`Failed to retrieve snapshot history: ${error.message}`);
    }
  }

  async cancelSnapshot(jobId: string, session: IAuth.ICredentials.IWeb3.IEntity) {
    try {
      // Verify ownership
      const snapshot = await this.getSnapshotByJobId(jobId);
      
      if (snapshot.userId !== session.walletId) {
        throw new Error('Unauthorized: Cannot cancel snapshot from another user');
      }

      // Cancel the job
      await this.cancelSnapshotJob(jobId);

      return {
        success: true,
        jobId: jobId,
        status: 'cancelled',
        cancelledAt: new Date().toISOString()
      };
    } catch (error) {
      throw new Error(`Failed to cancel snapshot: ${error.message}`);
    }
  }

  private validateTokenFormat(tokenId: string) {
    // Hedera format: 0.0.123456
    const hederaPattern = /^0\.0\.\d+$/;
    
    // XRP format validation (if needed)
    const xrpPattern = /^[A-Z0-9]{40}$/;

    if (!hederaPattern.test(tokenId) && !xrpPattern.test(tokenId)) {
      throw new Error('Invalid token ID format. Expected Hedera (0.0.123456) or XRP format.');
    }
  }

  private estimateCompletionTime(tokenId: string): string {
    // Mock estimation based on network and historical data
    const baseTime = this.isHederaToken(tokenId) ? 300 : 180; // seconds
    return `${baseTime} seconds (estimated)`;
  }

  private isHederaToken(tokenId: string): boolean {
    return /^0\.0\.\d+$/.test(tokenId);
  }

  private async setupProgressMonitoring(
    jobId: string, 
    callback?: (progress: number) => void
  ): Promise<void> {
    // Implementation for progress monitoring
    // This would typically involve WebSocket subscriptions
  }

  private async getSnapshotsByUser(userId: string, limit: number): Promise<any[]> {
    // Mock implementation - replace with actual database queries
    return [];
  }

  private async getSnapshotByJobId(jobId: string): Promise<any> {
    // Mock implementation - replace with actual database queries
    return { jobId, userId: 'user-id' };
  }

  private async cancelSnapshotJob(jobId: string): Promise<void> {
    // Implementation for cancelling Bull queue jobs
  }
}

interface SnapshotGenerationOptions {
  monitorProgress?: boolean;
  progressCallback?: (progress: number) => void;
  outputFormat?: 'json' | 'csv';
  includeMetadata?: boolean;
}

WebSocket Client Integration

import { Injectable } from '@nestjs/common';
import { io, Socket } from 'socket.io-client';

@Injectable()
export class SnapshotWebSocketClient {
  private socket: Socket;
  private activeSnapshots = new Map<string, SnapshotProgress>();

  connect(accessToken: string, serverUrl: string = 'ws://localhost:3000') {
    this.socket = io(`${serverUrl}/snapshots`, {
      auth: { accessToken },
      autoConnect: true,
      reconnection: true,
      reconnectionAttempts: 5,
      reconnectionDelay: 1000
    });

    this.setupEventHandlers();
  }

  private setupEventHandlers() {
    this.socket.on('connect', () => {
      console.log('Connected to snapshot WebSocket server');
    });

    this.socket.on('disconnect', (reason) => {
      console.log('Disconnected from snapshot server:', reason);
    });

    this.socket.on('snapshots_events', (event) => {
      this.handleSnapshotEvent(event);
    });

    this.socket.on('connect_error', (error) => {
      console.error('WebSocket connection error:', error);
    });
  }

  private handleSnapshotEvent(event: any) {
    const { type, payload } = event;

    switch (type) {
      case 'snapshots_waiting':
        this.handleSnapshotWaiting(payload);
        break;
      case 'snapshots_active':
        this.handleSnapshotActive(payload);
        break;
      case 'snapshots_progress':
        this.handleSnapshotProgress(payload);
        break;
      case 'snapshots_completed':
        this.handleSnapshotCompleted(payload);
        break;
      case 'snapshots_failed':
        this.handleSnapshotFailed(payload);
        break;
      default:
        console.warn('Unknown snapshot event type:', type);
    }
  }

  private handleSnapshotWaiting(payload: any) {
    console.log(`Snapshot ${payload.jobId} is waiting in queue`);
    
    this.activeSnapshots.set(payload.jobId, {
      jobId: payload.jobId,
      status: 'waiting',
      progress: 0,
      startedAt: new Date()
    });
  }

  private handleSnapshotActive(payload: any) {
    console.log(`Snapshot ${payload.jobId} started processing`);
    
    const snapshot = this.activeSnapshots.get(payload.jobId);
    if (snapshot) {
      snapshot.status = 'active';
      snapshot.progress = payload.progress || 0;
      snapshot.snapshotId = payload.snapshotId;
    }

    // Notify UI components
    this.notifyProgressUpdate(payload.jobId, 0, 'started');
  }

  private handleSnapshotProgress(payload: any) {
    console.log(`Snapshot ${payload.jobId} progress: ${payload.progress}%`);
    
    const snapshot = this.activeSnapshots.get(payload.jobId);
    if (snapshot) {
      snapshot.status = 'running';
      snapshot.progress = payload.progress;
      snapshot.lastUpdate = new Date();
    }

    // Notify UI components
    this.notifyProgressUpdate(payload.jobId, payload.progress, 'progress');
  }

  private handleSnapshotCompleted(payload: any) {
    console.log(`Snapshot ${payload.jobId} completed successfully`);
    
    const snapshot = this.activeSnapshots.get(payload.jobId);
    if (snapshot) {
      snapshot.status = 'completed';
      snapshot.progress = 100;
      snapshot.completedAt = new Date();
      snapshot.ipfsCid = payload.ipfsCid;
    }

    // Notify UI components
    this.notifyProgressUpdate(payload.jobId, 100, 'completed');
    
    // Clean up after delay
    setTimeout(() => {
      this.activeSnapshots.delete(payload.jobId);
    }, 60000); // Keep for 1 minute
  }

  private handleSnapshotFailed(payload: any) {
    console.error(`Snapshot ${payload.jobId} failed:`, payload.error);
    
    const snapshot = this.activeSnapshots.get(payload.jobId);
    if (snapshot) {
      snapshot.status = 'failed';
      snapshot.error = payload.error;
      snapshot.failedAt = new Date();
    }

    // Notify UI components
    this.notifyProgressUpdate(payload.jobId, snapshot?.progress || 0, 'failed', payload.error);
  }

  private notifyProgressUpdate(
    jobId: string, 
    progress: number, 
    status: string, 
    error?: string
  ) {
    // Emit custom events for UI components to listen to
    const customEvent = new CustomEvent('snapshotProgressUpdate', {
      detail: { jobId, progress, status, error, timestamp: new Date() }
    });
    
    if (typeof window !== 'undefined') {
      window.dispatchEvent(customEvent);
    }
  }

  getActiveSnapshots(): Map<string, SnapshotProgress> {
    return new Map(this.activeSnapshots);
  }

  getSnapshotStatus(jobId: string): SnapshotProgress | undefined {
    return this.activeSnapshots.get(jobId);
  }

  disconnect() {
    if (this.socket) {
      this.socket.disconnect();
    }
  }
}

interface SnapshotProgress {
  jobId: string;
  status: 'waiting' | 'active' | 'running' | 'completed' | 'failed';
  progress: number;
  snapshotId?: string;
  startedAt: Date;
  lastUpdate?: Date;
  completedAt?: Date;
  failedAt?: Date;
  ipfsCid?: string;
  error?: string;
}

Multi-Chain Plugin Implementation

import { Injectable } from '@nestjs/common';
import { Job } from 'bull';
import { ISnapshots } from '@hsuite/snapshots';

@Injectable()
export class CustomChainSnapshotHandler {
  
  async fetchAllTokenBalances(tokenId: string, job: Job): Promise<Array<any>> {
    try {
      const balances: any[] = [];
      let page = 0;
      const batchSize = 100;
      let hasMore = true;

      // Update job progress
      await job.progress(0);

      while (hasMore) {
        const batch = await this.fetchTokenHoldersBatch(tokenId, page, batchSize);
        
        if (batch.length === 0) {
          hasMore = false;
          break;
        }

        // Process batch
        for (const holder of batch) {
          const balance = await this.getAccountBalance(holder.accountId, tokenId);
          
          if (balance > 0) {
            balances.push({
              accountId: holder.accountId,
              balance: balance.toString(),
              lastTransactionTime: holder.lastTransaction,
              metadata: holder.metadata || {}
            });
          }
        }

        // Update progress
        page++;
        const progress = Math.min(95, (balances.length / this.estimateTotalHolders(tokenId)) * 100);
        await job.progress(progress);

        // Rate limiting
        await this.rateLimitDelay();
      }

      // Final processing
      await job.progress(100);
      
      return this.sortAndFormatBalances(balances);
    } catch (error) {
      throw new Error(`Failed to fetch token balances: ${error.message}`);
    }
  }

  validateToken(jobRequest: ISnapshots.IQueue.IUpload.IRequest): void {
    const tokenId = jobRequest.tokenId;
    
    // Custom token validation logic
    if (!this.isValidTokenFormat(tokenId)) {
      throw new Error(`Invalid token format for custom chain: ${tokenId}`);
    }

    // Additional validation
    if (!this.tokenExists(tokenId)) {
      throw new Error(`Token does not exist: ${tokenId}`);
    }
  }

  private async fetchTokenHoldersBatch(
    tokenId: string, 
    page: number, 
    batchSize: number
  ): Promise<any[]> {
    // Implementation specific to your blockchain
    // This would call the appropriate API for your network
    
    try {
      const response = await this.callBlockchainAPI(`/tokens/${tokenId}/holders`, {
        page,
        limit: batchSize
      });
      
      return response.data || [];
    } catch (error) {
      throw new Error(`API call failed: ${error.message}`);
    }
  }

  private async getAccountBalance(accountId: string, tokenId: string): Promise<number> {
    // Get specific account balance for the token
    try {
      const response = await this.callBlockchainAPI(`/accounts/${accountId}/tokens/${tokenId}`);
      return response.balance || 0;
    } catch (error) {
      console.warn(`Failed to get balance for ${accountId}: ${error.message}`);
      return 0;
    }
  }

  private async callBlockchainAPI(endpoint: string, params?: any): Promise<any> {
    // Mock API call - replace with actual blockchain API calls
    await new Promise(resolve => setTimeout(resolve, 100)); // Simulate API delay
    
    return {
      data: [],
      balance: 0
    };
  }

  private async rateLimitDelay(): Promise<void> {
    // Implement appropriate rate limiting for your blockchain
    await new Promise(resolve => setTimeout(resolve, 1000)); // 1 second delay
  }

  private estimateTotalHolders(tokenId: string): number {
    // Estimate total holders for progress calculation
    // This could be cached or retrieved from token metadata
    return 10000; // Mock estimate
  }

  private isValidTokenFormat(tokenId: string): boolean {
    // Implement token format validation for your chain
    return tokenId.length > 0 && /^[a-zA-Z0-9]+$/.test(tokenId);
  }

  private tokenExists(tokenId: string): boolean {
    // Check if token exists on the blockchain
    // This would typically involve an API call
    return true; // Mock validation
  }

  private sortAndFormatBalances(balances: any[]): any[] {
    // Sort by balance (descending) and format
    return balances
      .sort((a, b) => parseFloat(b.balance) - parseFloat(a.balance))
      .map(balance => ({
        ...balance,
        balance: this.formatBalance(balance.balance),
        rank: balances.indexOf(balance) + 1
      }));
  }

  private formatBalance(balance: string): string {
    // Format balance according to token decimals
    return parseFloat(balance).toFixed(8);
  }
}

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Integration

Required Dependencies

{
  "@nestjs/common": "^10.4.2",
  "@nestjs/core": "^10.4.2",
  "@hsuite/hashgraph": "^2.0.2",
  "@hsuite/auth-types": "^2.1.2",
  "@hsuite/ipfs": "^2.0.5",
  "@hsuite/nestjs-swagger": "^1.0.3",
  "@hashgraph/sdk": "^2.62.0",
  "@compodoc/compodoc": "^1.1.23"
}

Module Integration

import { Module } from '@nestjs/common';
import { SnapshotsModule } from '@hsuite/snapshots';

@Module({
  imports: [
    SnapshotsModule.forRootAsync({
      imports: [ConfigModule],
      useFactory: async (configService: ConfigService) => ({
        bull: {
          redis: {
            socket: {
              host: configService.get('REDIS_HOST', 'localhost'),
              port: configService.get('REDIS_PORT', 6379)
            },
            password: configService.get('REDIS_PASSWORD'),
            username: configService.get('REDIS_USERNAME'),
            database: configService.get('REDIS_DATABASE', 0)
          },
          defaultJobOptions: {
            attempts: 3,
            backoff: { type: 'exponential', delay: 1000 },
            removeOnComplete: 10,
            removeOnFail: 5
          }
        },
        jwt: {
          secret: configService.get('JWT_SECRET'),
          signOptions: { 
            expiresIn: '1h',
            issuer: 'hsuite-snapshots'
          }
        }
      }),
      inject: [ConfigService]
    })
  ]
})
export class AppModule {}

Environment Configuration

# Redis Configuration
REDIS_HOST=localhost
REDIS_PORT=6379
REDIS_PASSWORD=your-redis-password
REDIS_USERNAME=default
REDIS_DATABASE=0

# JWT Configuration
JWT_SECRET=your-jwt-secret

# Snapshot Settings
SNAPSHOT_BATCH_SIZE=25
SNAPSHOT_RATE_LIMIT_DELAY=1000
SNAPSHOT_MAX_RETRIES=3

# IPFS Configuration
IPFS_API_URL=http://localhost:5001
IPFS_GATEWAY_URL=http://localhost:8080

Processing Flow

📊 Snapshot Generation Pipeline

1. Request Validation - Token format and authentication verification

2. Queue Management - Bull queue job creation with Redis persistence

3. Multi-Chain Processing - Plugin-based blockchain data fetching

4. Progress Tracking - Real-time WebSocket updates during generation

5. IPFS Upload - Decentralized storage of final snapshot data

6. Notification - Complete event broadcasting to clients

⚡ Performance Optimizations

• Rate Limiting Compliance - Network-specific API batching and delays

• Asynchronous Processing - Non-blocking queue-based generation

• Real-time Updates - Efficient WebSocket event broadcasting

• Error Recovery - Automatic retry with exponential backoff

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📸 Multi-Ledger Snapshots: Comprehensive token holder snapshot generation with support for Hedera Hashgraph and Ripple/XRP Ledger networks.

🌐 Real-time Tracking: WebSocket-based progress monitoring with JWT authentication and automatic reconnection handling.

🔌 Plugin Architecture: Extensible multi-chain support with standardized interfaces for easy blockchain network integration.

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