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| """ | |
| This module contains functions for rate limiting requests. | |
| The rate limiting system operates on two levels: | |
| 1. User-level rate limiting: Each user (identified by a token) has a | |
| configurable minimum interval between requests. | |
| 2. System-wide rate limiting: There is a global limit on the total number of | |
| requests across all users within a specified time period. | |
| """ | |
| from datetime import datetime | |
| import signal | |
| import sys | |
| from typing import Dict | |
| from uuid import uuid4 | |
| from apscheduler.schedulers import background | |
| import gradio as gr | |
| class InvalidTokenException(Exception): | |
| pass | |
| class UserRateLimitException(Exception): | |
| pass | |
| class SystemRateLimitException(Exception): | |
| pass | |
| class RateLimiter: | |
| def __init__(self, limit=10000, period_in_seconds=60 * 60 * 24): | |
| # Maps tokens to the last time they made a request. | |
| # E.g, {"sometoken": datetime(2021, 8, 1, 0, 0, 0)} | |
| self.last_request_times: Dict[str, datetime] = {} | |
| # The number of requests made. | |
| # This count is reset to zero at the end of each period. | |
| self.request_count = 0 | |
| # The maximum number of requests allowed within the time period. | |
| self.limit = limit | |
| self.scheduler = background.BackgroundScheduler() | |
| self.scheduler.add_job(self._remove_old_tokens, | |
| "interval", | |
| seconds=60 * 60 * 24) | |
| self.scheduler.add_job(self._reset_request_count, | |
| "interval", | |
| seconds=period_in_seconds) | |
| self.scheduler.start() | |
| def check_rate_limit(self, token: str): | |
| if not token or token not in self.last_request_times: | |
| raise InvalidTokenException() | |
| if (datetime.now() - self.last_request_times[token]).seconds < 5: | |
| raise UserRateLimitException() | |
| if self.request_count >= self.limit: | |
| raise SystemRateLimitException() | |
| self.last_request_times[token] = datetime.now() | |
| self.request_count += 1 | |
| def initialize_request(self, token: str): | |
| self.last_request_times[token] = datetime.min | |
| def _remove_old_tokens(self): | |
| for token, last_request_time in dict(self.last_request_times).items(): | |
| if (datetime.now() - last_request_time).days >= 1: | |
| del self.last_request_times[token] | |
| def _reset_request_count(self): | |
| self.request_count = 0 | |
| rate_limiter = RateLimiter() | |
| def set_token(app: gr.Blocks): | |
| def set_token_server(): | |
| new_token = uuid4().hex | |
| rate_limiter.initialize_request(new_token) | |
| return new_token | |
| set_token_client = """ | |
| function(newToken) { | |
| const expiresDateString = new Date(Date.now() + 24 * 60 * 60 * 1000).toUTCString(); | |
| document.cookie = `arena_token=${newToken}; expires=${expiresDateString};`; | |
| } | |
| """ | |
| token = gr.Textbox(visible=False) | |
| app.load(fn=set_token_server, outputs=[token]) | |
| token.change(fn=lambda _: None, js=set_token_client, inputs=[token]) | |
| def signal_handler(sig, frame): | |
| del sig, frame # Unused. | |
| rate_limiter.scheduler.shutdown() | |
| sys.exit(0) | |
| if gr.NO_RELOAD: | |
| # Catch signal to ensure scheduler shuts down when server stops. | |
| signal.signal(signal.SIGINT, signal_handler) | |