在Python中使用AOP实现Redis缓存示例

import redis 
enable=True 
#enable=False 
def readRedis(key): 
  if enable: 
    r = redis.Redis(host='10.224.38.31', port=8690,db=0, password='xxxx')   
    val = r.get(key) 
    if val is None: 
      print "can not find data for KEY:%s \n" % (key) 
      return None 
    else: 
      print "====Get VALUE from Redis by KEY:%s \n" % ( key) 
      return pickle.loads(val) 
  else: 
    print "disable cache" 
   
def writeRedis(key, val): 
  r = redis.Redis(host='10.224.38.31', port=8690,db=0, password='xxxx') 
  if val is None: 
    print "Val is None, don't save it to redis \n" 
  else: 
    r.set(key, pickle.dumps(val) ) 
    r.expire(key, 60*60*24*7) #1week 
    print "====Write value of KEY:%s to redis \n" % (key) 
   
import pickle, functools 
def cache(f): 
 def wrapper(*args, **kwargs): 
  key = pickle.dumps((f.__name__, args, kwargs)).replace("\n","") 
  val = readRedis(key) 
  if val is None: 
   val = f(*args, **kwargs) # call the wrapped function, save in cache 
   writeRedis(key, val) 
  return val # read value from cache 
 functools.update_wrapper(wrapper, f) # update wrapper's metadata 
 return wrapper  
 
@cache 
def foo(n): 
 return n*2 
 
foo(10) # first call with parameter 10, sleeps 
foo(10) # returns immediately 
foo(15) # returns immediately 
foo(19) # returns immediately