Is there a rate limiting feature in Kanna to prevent server overload?

Kanna, is not a web scraping library but rather a Swift library for XML/HTML parsing. If you're referring to Kanna in the context of Swift programming, it does not include a built-in rate limiting feature since it is a parsing library and not a network request library. Rate limiting is typically implemented when making requests to a server, rather than when parsing the data received from those requests.

However, if you're talking about rate limiting in the context of web scraping, you would implement rate limiting at the stage where you make HTTP requests to the server you're scraping from. You would have to manage this yourself or utilize a third-party library to handle the network requests with rate limiting.

For example, in Python, you can use the requests library in combination with time.sleep() to implement a simple rate limiting mechanism:

import requests
import time

urls = ['http://example.com/page1', 'http://example.com/page2', '...']

for url in urls:
    response = requests.get(url)
    # Process the response with Kanna or any other parser here

    # Sleep for a specified amount of time to rate limit requests
    time.sleep(1) # Sleep for 1 second between requests

If you require more sophisticated rate limiting (e.g., a certain number of requests per minute), you might consider using the ratelimit library or requests-throttler:

from ratelimit import limits, sleep_and_retry
import requests

@sleep_and_retry
@limits(calls=10, period=60)  # 10 requests per minute
def call_api(url):
    response = requests.get(url)
    # Your code to process the response goes here
    return response

urls = ['http://example.com/page1', 'http://example.com/page2', '...']

for url in urls:
    response = call_api(url)

In JavaScript (for Node.js), you can use libraries such as axios with axios-rate-limit or simply use setTimeout for basic rate limiting:

const axios = require('axios');
const rateLimit = require('axios-rate-limit');

// Create an axios instance with rate limiting
const http = rateLimit(axios.create(), { maxRequests: 10, perMilliseconds: 60000 });

const urls = ['http://example.com/page1', 'http://example.com/page2', '...'];

urls.forEach(async (url) => {
    try {
        const response = await http.get(url);
        // Your code to process the response goes here
    } catch (error) {
        console.error(error);
    }
    // Note: The rate-limited axios instance will handle waiting between requests
});

When implementing rate limiting, it's essential to respect the robots.txt file of the website you're scraping and the terms of service to avoid legal issues or being blocked by the website.