Python: Flyweight Pattern



DuFlyweight.py

# 享元模式 Flyweight Pattern  geovindu,Geovin Du,涂聚文
import time
 
class Arrow:
    def __init__(self, x, y, z, velocity):
        self.x = x
        self.y = y
        self.z = z
        self.velocity = velocity
        self.shape = 'cone'
 
 
class ArrowContext:
    def __init__(self, x, y, z, velocity):
        self.x = x
        self.y = y
        self.z = z
        self.velocity = velocity
 
 
class ArrowFlyweight:
    def __init__(self):
        self.shape = 'cone'
        self.arrows = []
 
    def arrow_factory(self, x, y, z, velocity):
        arr = []
        for b in self.arrows:
            if b.x == x and b.y == y and b.z == z and b.velocity == velocity:
                arr.append(b)
        if not arr:
            arr = Arrow(x, y, z, velocity)
            self.arrows.append(arr)
        else:
            arr = arr[0]
 
        return arr
 
    def print_arrows(self):
        print('排列:')
        for arrow in self.arrows:
            print(str(arrow.x) + ' ' + str(arrow.y) + ' ' + str(arrow.z) + ' ' + str(arrow.velocity))
 
 
# Flyweight Object: HTTP Request result:  geovindu,Geovin Du,涂聚文 格式，排版要对齐，否则调用时，方法到提取不到
class WebRequestResult(object):
   # The time (in munutes, converted to seconds) to cache a request.
   # This is a 1-minute cahce.
   CACHE_TIME_MINUTES = 1 * 60
 
   def __init__(self, data):
       # The Flyweight data:
       self.data = data
       self.cacheUntilTime = time.time() + WebRequestResult.CACHE_TIME_MINUTES
 
   def isExpired(self):
       return time.time() > self.cacheUntilTime
 
# WebRequestCache Factory:
class WebRequestCache(object):
    def __init__(self):
        self.cache = {}
 
    # For simplicity, we'll be concurrent with our requests:
    def getRequest(self, url):
        result = None
 
        if url in self.cache:
            result = self.cache[url]
 
        if result is None or result.isExpired():
            result = WebRequestResult("一些数据来自于 " + str(url))
 
            self.cache[url] = result
 
        return result

main.py  调用

# 享元模式 Flyweight Pattern
 
obj =DuFlyweight.ArrowFlyweight()
obj.arrow_factory(1, 1, 1, 1)
obj.arrow_factory(1, 2, 5, 1)
obj.arrow_factory(1, 1, 1, 1)
obj.print_arrows()
 
geovinduObject =DuFlyweight.ArrowFlyweight()
geovinduObject.arrow_factory('geovindu', 'dusystem.com', '1', '塗聚文')
geovinduObject.arrow_factory('geovin', 'du', '5', '1')
geovinduObject.arrow_factory('geovi', 'studio', '1', '涂聚文')
geovinduObject.print_arrows()
 
webCache = DuFlyweight.WebRequestCache()
 
request = webCache.getRequest("https://coronavirus-tracker-api.herokuapp.com/all")
print(request.data) # output: Some cool data from mycoolapi/endpoint
 
print(request.isExpired()) # output: False

输出：

排列:
1 1 1 1
1 2 5 1
排列:
geovindu dusystem.com 1 塗聚文
geovin du 5 1
geovi studio 1 涂聚文
一些数据来自于 https://coronavirus-tracker-api.herokuapp.com/all
False