46 lines
1.0 KiB
Python
46 lines
1.0 KiB
Python
|
# coding: utf-8
|
||
|
|
|
||
|
|
"""
|
||
|
|
Caching function for pictures.
|
||
|
|
"""
|
||
|
|
|
||
|
|
from __future__ import absolute_import, print_function, unicode_literals
|
||
|
|
|
||
|
|
import requests
|
||
|
|
|
||
|
|
class MemoryCache(object):
|
||
|
|
def __init__(self, on_miss):
|
||
|
|
self.hits = 0
|
||
|
|
self.misses = 0
|
||
|
|
self.map = {}
|
||
|
|
self.on_miss = on_miss
|
||
|
|
|
||
|
|
def get(self, key):
|
||
|
|
cached = self.map.get(key, None)
|
||
|
|
if cached is not None:
|
||
|
|
self.hits += 1
|
||
|
|
return cached
|
||
|
|
|
||
|
|
item = self.map[key] = self.on_miss(key)
|
||
|
|
self.misses += 1
|
||
|
|
return item
|
||
|
|
|
||
|
|
def total(self):
|
||
|
|
return self.hits + self.misses
|
||
|
|
|
||
|
|
def hit_rate(self):
|
||
|
|
assert self.total() > 0
|
||
|
|
return 100 * self.hits // self.total()
|
||
|
|
|
||
|
|
def miss_rate(self):
|
||
|
|
assert self.total() > 0
|
||
|
|
return 100 * self.misses // self.total()
|
||
|
|
|
||
|
|
class ImageCache(MemoryCache):
|
||
|
|
@staticmethod
|
||
|
|
def retrieve_photo(url):
|
||
|
|
return requests.get(url)
|
||
|
|
|
||
|
|
def __init__(self):
|
||
|
|
super(self.__class__, self).__init__(on_miss=ImageCache.retrieve_photo)
|