Rate Limiting

-- Lua script for Redis
local key = KEYS[1]
local capacity = tonumber(ARGV[1])
local tokens = tonumber(ARGV[2])
local interval = tonumber(ARGV[3])

local bucket = redis.call('HMGET', key, 'tokens', 'last_refill')
local current_tokens = tonumber(bucket[1]) or capacity
local last_refill = tonumber(bucket[2]) or 0

local now = redis.call('TIME')[1]
local elapsed = now - last_refill
current_tokens = math.min(capacity, 
    current_tokens + elapsed * tokens / interval)

if current_tokens >= 1 then
  current_tokens = current_tokens - 1
  redis.call('HMSET', key, 'tokens', current_tokens, 'last_refill', now)
  redis.call('EXPIRE', key, interval * 2)
  return 1
else
  return 0
end

import time
from collections import deque

class SlidingWindowRateLimiter:
    def __init__(self, limit, window_size):
        self.limit = limit
        self.window_size = window_size
        self.requests = deque()

    def allow_request(self):
        now = time.time()
        # Remove old requests
        while (self.requests and 
               self.requests[0] <= now - self.window_size):
            self.requests.popleft()

        # Check if limit exceeded
        if len(self.requests) < self.limit:
            self.requests.append(now)
            return True
        return False