openmax-server/src/common/rate_limiter.py

52 lines
1.5 KiB
Python

import time, logging
class RateLimiter:
"""
ip rate limiter using sliding window algorithm
"""
def __init__(self, max_attempts=5, window_seconds=60):
self.max_attempts = max_attempts
self.window_seconds = window_seconds
self.attempts = {} # {ip: [timestamp, ...]}
self.logger = logging.getLogger(__name__)
def is_allowed(self, ip: str) -> bool:
now = time.monotonic()
cutoff = now - self.window_seconds
if ip not in self.attempts:
self.attempts[ip] = []
self.attempts[ip] = [t for t in self.attempts[ip] if t > cutoff]
if len(self.attempts[ip]) >= self.max_attempts:
self.logger.warning(f"request limit exceeded for {ip}: {len(self.attempts[ip])}/{self.max_attempts}")
return False
self.attempts[ip].append(now)
return True
def remaining(self, ip: str) -> int:
now = time.monotonic()
cutoff = now - self.window_seconds
entries = self.attempts.get(ip, [])
active = [t for t in entries if t > cutoff]
return max(0, self.max_attempts - len(active))
def retry_after(self, ip: str) -> int:
entries = self.attempts.get(ip, [])
if not entries:
return 0
now = time.monotonic()
cutoff = now - self.window_seconds
active = [t for t in entries if t > cutoff]
if len(active) < self.max_attempts:
return 0
oldest = min(active)
return max(0, int(oldest + self.window_seconds - now) + 1)