perf: 延迟执行一个函数

apps/common/decorator.py

@@ -1,5 +1,11 @@
 # -*- coding: utf-8 -*-
 #
+import functools
+import threading
+import time
+import uuid
+
+from django.core.cache import cache
 from django.db import transaction
 
 
@@ -7,13 +13,16 @@ def on_transaction_commit(func):
     """
     如果不调用on_commit, 对象创建时添加多对多字段值失败
     """
+
     def inner(*args, **kwargs):
         transaction.on_commit(lambda: func(*args, **kwargs))
+
     return inner
 
 
 class Singleton(object):
     """ 单例类 """
+
     def __init__(self, cls):
         self._cls = cls
         self._instance = {}
@@ -22,3 +31,38 @@ class Singleton(object):
         if self._cls not in self._instance:
             self._instance[self._cls] = self._cls()
         return self._instance[self._cls]
+
+
+def _run_func_if_is_last(ttl, func, *args, **kwargs):
+    ix = uuid.uuid4().__str__()
+    key = f'DELAY_RUN_{func.__name__}'
+    cache.set(key, ix, ttl)
+    st = (ttl - 2 > 1) and ttl - 2 or 1
+    time.sleep(st)
+    got = cache.get(key, None)
+
+    if ix == got:
+        func(*args, **kwargs)
+        cache.delete(key)
+
+
+def delay_run(ttl=5):
+    def inner(func):
+        @functools.wraps(func)
+        def wrapper(*args, **kwargs):
+            t = threading.Thread(target=_run_func_if_is_last, args=(ttl, func, *args), kwargs=kwargs)
+            t.start()
+
+        return wrapper
+
+    return inner
+
+
+@delay_run(ttl=10)
+def run_it_many(username, year=2000):
+    print("Hello, %s, now is %s" % (username, year))
+
+
+if __name__ == '__main__':
+    for i in range(20):
+        run_it_many('test', 2000)