Rate Limiting with Queue Rejection in Python

from collections import deque
import time


class RateLimiter:
    def __init__(self, max_queue_size=3):
        self.queue = deque()
        self.max_queue_size = max_queue_size
        self.rejected_count = 0

    def submit(self, task_name):
        if len(self.queue) >= self.max_queue_size:
            self.rejected_count += 1
            return f"REJECT {task_name} - queue full"
        self.queue.append(task_name)
        return f"ACCEPT {task_name} - queued"

    def process_next(self):
        if self.queue:
            return f"PROCESS {self.queue.popleft()}"
        return "PROCESS - queue empty"


if __name__ == "__main__":
    limiter = RateLimiter(max_queue_size=3)

    # Simulate a burst of submissions
    for i in range(5):
        result = limiter.submit(f"task_{i}")
        print(result)

    print("---")
    while limiter.queue:
        print(limiter.process_next())
    print("---")
    print(f"Total rejected: {limiter.rejected_count}")