File Transfer Protocol

File Transfer Implementation Examples

Modern File Upload Component

// Advanced File Upload System
interface UploadOptions {
  maxFileSize: number;
  allowedTypes: string[];
  chunkSize?: number;
  concurrent?: number;
}

class SecureFileUploader {
  private options: UploadOptions;
  private uploadQueue: Map = new Map();

  constructor(options: UploadOptions) {
    this.options = options;
  }

  async uploadFile(file: File): Promise {
    // Validate file before upload
    await this.validateFile(file);
    
    const uploadId = this.generateUploadId();
    const chunks = this.createChunks(file);
    
    const uploadJob: UploadJob = {
      id: uploadId,
      file,
      chunks,
      progress: 0,
      status: 'uploading'
    };

    this.uploadQueue.set(uploadId, uploadJob);
    return this.processUpload(uploadJob);
  }

  private async processUpload(job: UploadJob): Promise {
    const { chunks } = job;
    const uploadPromises = chunks.map((chunk, index) => 
      this.uploadChunk(job.id, chunk, index)
    );

    try {
      await Promise.all(uploadPromises);
      return await this.finalizeUpload(job.id);
    } catch (error) {
      await this.handleUploadError(job.id, error);
      throw error;
    }
  }
}

Secure File Processing

// Server-side File Processing
class FileProcessor {
  static async processUpload(fileData, options = {}) {
    // Security validation
    await this.validateFileType(fileData);
    await this.scanForMalware(fileData);
    
    // Image optimization
    if (this.isImage(fileData)) {
      fileData = await this.optimizeImage(fileData);
    }
    
    // Generate unique filename
    const filename = this.generateSecureFilename(fileData.originalName);
    
    // Store with metadata
    const result = await this.storeFile(filename, fileData, {
      uploadedBy: options.userId,
      uploadDate: new Date(),
      fileSize: fileData.size,
      mimeType: fileData.type
    });
    
    return result;
  }
  
  static async optimizeImage(imageData) {
    const sharp = require('sharp');
    
    return sharp(imageData.buffer)
      .resize(1920, 1080, { fit: 'inside', withoutEnlargement: true })
      .jpeg({ quality: 85, progressive: true })
      .png({ compressionLevel: 9 })
      .webp({ quality: 90 })
      .toBuffer();
  }
}

Cloud Storage Integration

# Python Cloud Storage Implementation
import boto3
from azure.storage.blob import BlobServiceClient
import asyncio

class CloudFileManager:
    def __init__(self, provider='aws'):
        self.provider = provider
        self.setup_client()
    
    def setup_client(self):
        if self.provider == 'aws':
            self.client = boto3.client('s3')
        elif self.provider == 'azure':
            self.client = BlobServiceClient.from_connection_string(conn_str)
    
    async def upload_with_redundancy(self, file_data, filename):
        """Upload to multiple regions for redundancy"""
        regions = ['us-east-1', 'eu-west-1', 'ap-southeast-1']
        
        upload_tasks = [
            self.upload_to_region(file_data, filename, region)
            for region in regions
        ]
        
        results = await asyncio.gather(*upload_tasks, return_exceptions=True)
        
        # Return primary upload result
        return results[0] if not isinstance(results[0], Exception) else None
    
    def generate_presigned_url(self, filename, expiration=3600):
        """Generate secure download URLs"""
        return self.client.generate_presigned_url(
            'get_object',
            Params={'Bucket': 'my-bucket', 'Key': filename},
            ExpiresIn=expiration
        )