perf: 抢购流程第一层优化

- timer: 多NTP源取中位数提高精度,新增wait_until_early提前触发
- snatcher: 并发2个tab竞争抢购,reload用commit级别不等渲染
- snatcher: 重试间隔从300ms降到50ms,最大重试5次
- snatcher: 用waitForSelector替代固定sleep,按钮出现即点击
- snatcher: 开售前500ms发起reload,抢占先机
- main.py: 同步所有优化

utils/timer.py

@@ -3,47 +3,67 @@ import asyncio
 import ntplib
 from datetime import datetime
 
+
 class PrecisionTimer:
     def __init__(self):
-        self.offset = 0 # 服务器时间 - 本地时间
+        self.offset = 0  # 服务器时间 - 本地时间
 
     def sync_time(self):
-        """
-        同步 NTP 时间，计算偏移量
-        """
-        try:
-            client = ntplib.NTPClient()
-            response = client.request('pool.ntp.org', version=3)
-            self.offset = response.tx_time - time.time()
-            print(f"时间同步完成，偏移量: {self.offset:.3f}s")
-        except Exception as e:
-            print(f"NTP同步失败: {e}，将使用系统时间")
+        """多次 NTP 同步取中位数，提高精度"""
+        offsets = []
+        servers = ['ntp.aliyun.com', 'ntp.tencent.com', 'pool.ntp.org']
+        for server in servers:
+            try:
+                client = ntplib.NTPClient()
+                resp = client.request(server, version=3)
+                offsets.append(resp.tx_time - time.time())
+            except Exception:
+                continue
+        if offsets:
+            offsets.sort()
+            self.offset = offsets[len(offsets) // 2]
+            print(f"时间同步完成，偏移量: {self.offset:.3f}s (采样{len(offsets)}个)")
+        else:
+            print("NTP同步失败，将使用系统时间")
 
     def get_server_time(self):
         return time.time() + self.offset
 
     async def wait_until(self, target_time_str):
-        """
-        等待直到目标时间 (格式: 2026-02-01 10:00:00)
-        """
+        """等待直到目标时间，最后阶段忙等保证精度"""
         target_dt = datetime.strptime(target_time_str, "%Y-%m-%d %H:%M:%S")
-        target_timestamp = target_dt.timestamp()
-        
-        print(f"正在等待目标时间: {target_time_str}")
-        
+        target_ts = target_dt.timestamp()
+
+        print(f"等待目标时间: {target_time_str}")
+
         while True:
-            current_time = self.get_server_time()
-            remaining = target_timestamp - current_time
-            
+            now = self.get_server_time()
+            remaining = target_ts - now
+
             if remaining <= 0:
-                print("目标时间已到！触发抢购！")
+                print("目标时间已到！")
                 break
-            
-            # 动态调整调整休眠时间以节省 CPU 并保持精度
-            if remaining > 1:
-                await asyncio.sleep(remaining - 0.5)
+            elif remaining > 10:
+                await asyncio.sleep(remaining - 10)
+            elif remaining > 2:
+                await asyncio.sleep(0.5)
+            elif remaining > 0.1:
+                await asyncio.sleep(0.01)
+            # remaining <= 0.1: 忙等，不 sleep
+
+    async def wait_until_early(self, target_time_str, early_ms=500):
+        """提前 early_ms 毫秒触发，用于需要预操作的场景"""
+        target_dt = datetime.strptime(target_time_str, "%Y-%m-%d %H:%M:%S")
+        target_ts = target_dt.timestamp() - (early_ms / 1000.0)
+
+        while True:
+            now = self.get_server_time()
+            remaining = target_ts - now
+            if remaining <= 0:
+                break
+            elif remaining > 10:
+                await asyncio.sleep(remaining - 10)
+            elif remaining > 2:
+                await asyncio.sleep(0.5)
             elif remaining > 0.1:
                 await asyncio.sleep(0.01)
-            else:
-                # 最后一刻进入忙等以获取最高精度
-                pass