75 lines
3.1 KiB
Python
75 lines
3.1 KiB
Python
import threading
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import time
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from functools import wraps
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from flask import current_app, jsonify, stream_with_context, Response, request
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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):
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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.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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目前的超时机制是通过 ExecutionTimeoutMonitor 的标志位来通知生成器超时。
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但是，生成器只有在下一次 yield 时才会检查标志位，因此不会在当前执行的代码段中间强行中断。
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"""
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time.sleep(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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current_app.logger.error(f"Request execution exceeded {self.timeout} seconds and was terminated.")
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def start(self):
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self.thread.start()
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def require_connection_limit(timeout=900):
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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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blueprint = request.blueprint
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limiter = current_app.connection_limiters.get(blueprint, current_app.connection_limiters.get('default'))
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if limiter is None:
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current_app.logger.error(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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# 获取信号量（阻塞）
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acquired = limiter.semaphore.acquire(blocking=True)
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if not acquired:
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current_app.logger.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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try:
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# 启动执行超时监控器
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monitor = ExecutionTimeoutMonitor(timeout, limiter.semaphore)
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monitor.start()
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generator = f(*args, **kwargs)
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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 generator:
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if monitor.is_timeout:
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current_app.logger.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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finally:
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if not monitor.is_timeout:
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limiter.semaphore.release() # 正常结束时释放信号量
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return Response(generator_wrapper(), mimetype='text/event-stream')
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except Exception as e:
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limiter.semaphore.release() # 异常时释放信号量
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current_app.logger.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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class ConnectionLimiter:
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def __init__(self, max_connections=1):
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self.semaphore = threading.Semaphore(max_connections)
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