116 lines
4.9 KiB
Python
116 lines
4.9 KiB
Python
# flask_app/ConnectionLimiter.py
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import threading
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import logging
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from functools import wraps
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from flask import jsonify, request, Response, stream_with_context, current_app, g
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# 配置模块级别的日志记录器
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logger = logging.getLogger(__name__)
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class ExecutionTimeoutMonitor:
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"""监控请求执行时间，超时后释放信号量"""
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def __init__(self, timeout, semaphore, logger):
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self.timeout = timeout
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self.semaphore = semaphore
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self.is_timeout = False
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self.stopped = threading.Event()
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self.logger = logger
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self.thread = threading.Thread(target=self._monitor)
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self.thread.daemon = True
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def _monitor(self):
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"""等待指定时间后标记为超时并释放信号量"""
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if not self.stopped.wait(self.timeout):
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self.is_timeout = True
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self.semaphore.release() # 超时后释放信号量
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self.logger.error(f"请求执行时间超过 {self.timeout} 秒并被终止。")
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def start(self):
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self.thread.start()
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def stop(self):
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self.stopped.set()
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self.thread.join()
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class ConnectionLimiter:
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def __init__(self, max_connections=10):
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self.semaphore = threading.Semaphore(max_connections)
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#当请求超时时，连接资源（即信号量）会被释放，但是正在执行的程序不会被终止。这意味着虽然新的请求可以继续被接受和处理，但超时的请求仍然会在后台继续运行，直到完成或遇到其他中断条件。
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def require_connection_limit(timeout=900):
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"""装饰器：确保路由使用连接限制，并监控请求执行时间"""
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def decorator(f):
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@wraps(f)
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def wrapped(*args, **kwargs):
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# 统一获取 logger 对象
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logger_to_use = getattr(g, 'logger', logger)
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blueprint = request.blueprint
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limiter = current_app.connection_limiters.get(
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blueprint, current_app.connection_limiters.get('default'))
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if limiter is None:
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logger_to_use.error(
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f"未为蓝图 '{blueprint}' 配置 ConnectionLimiter，并且未设置默认限流器。")
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return jsonify({'error': '服务器配置错误'}), 500
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acquired = limiter.semaphore.acquire(blocking=True)
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if not acquired:
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logger_to_use.warning("并发连接过多")
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return jsonify({'error': '并发连接过多'}), 429
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# 启动执行超时监控器
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monitor = ExecutionTimeoutMonitor(timeout, limiter.semaphore, logger_to_use)
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monitor.start()
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try:
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result = f(*args, **kwargs)
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if isinstance(result, Response):
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# 对于 Response 对象，使用 call_on_close 释放信号量
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def release_semaphore():
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if not monitor.is_timeout:
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limiter.semaphore.release()
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monitor.stop()
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logger_to_use.info("Response Object 正确释放")
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result.call_on_close(release_semaphore)
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return result
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elif hasattr(result, '__iter__') and not isinstance(result, (str, bytes)):
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# 处理生成器响应
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@stream_with_context
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def generator_wrapper():
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try:
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for item in result:
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if monitor.is_timeout:
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logger_to_use.error("请求执行时间超过限制并被终止。")
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break
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yield item
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except GeneratorExit:
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# 客户端断开连接
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logger_to_use.info("客户端断开连接")
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finally:
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if not monitor.is_timeout:
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limiter.semaphore.release()
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monitor.stop()
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logger_to_use.info("在生成器的 finally 中释放信号量并停止监控器")
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return Response(generator_wrapper(), mimetype='text/event-stream')
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else:
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# 对于其他类型的响应，返回前释放信号量
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if not monitor.is_timeout:
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limiter.semaphore.release()
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monitor.stop()
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logger_to_use.info("Semaphore released for non-Response, non-generator result")
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return result
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except Exception as e:
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if not monitor.is_timeout:
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limiter.semaphore.release()
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monitor.stop()
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logger_to_use.error(f"路由处理异常: {e}")
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return jsonify({'error': '内部服务器错误'}), 500
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return wrapped
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return decorator
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