Files
data-entry-app/backend/app/core/rate_limit.py
T
2026-05-10 09:46:07 +12:00

40 lines
1.2 KiB
Python

from __future__ import annotations
import time
from collections import deque
from dataclasses import dataclass
from threading import Lock
from fastapi import HTTPException, Request, status
@dataclass
class SlidingWindowRateLimiter:
limit: int
window_seconds: int
def __post_init__(self) -> None:
self._events: dict[str, deque[float]] = {}
self._lock = Lock()
def hit(self, key: str) -> None:
now = time.time()
floor = now - self.window_seconds
with self._lock:
bucket = self._events.setdefault(key, deque())
while bucket and bucket[0] <= floor:
bucket.popleft()
if len(bucket) >= self.limit:
raise HTTPException(
status_code=status.HTTP_429_TOO_MANY_REQUESTS,
detail="Too many requests. Please try again later.",
)
bucket.append(now)
def request_client_key(request: Request, *, suffix: str = "") -> str:
forwarded_for = request.headers.get("x-forwarded-for", "")
client_ip = forwarded_for.split(",", 1)[0].strip() if forwarded_for else (request.client.host if request.client else "unknown")
return f"{client_ip}:{suffix}" if suffix else client_ip