50 lines
1.7 KiB
Python
50 lines
1.7 KiB
Python
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import requests
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import threading
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import redis
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from flask import make_response, abort
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class ImgProxyCache(object):
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def __init__(self, redis_uri='redis://', timeout=1, expire=60*60*6,
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prefix='img_proxy'):
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self.redis = redis.StrictRedis.from_url(redis_uri)
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self.timeout = timeout
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self.expire = expire
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self.prefix = prefix
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self.redis.client_setname('img_proxy')
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def key(self, keytype, url):
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return '{prefix}:{keytype}:{url}'.format(
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prefix=self.prefix,
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keytype=keytype,
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url=url)
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def fetch_and_cache(self, url):
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resp = requests.get(url)
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if(resp.status_code != 200):
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return
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mime = resp.headers.get('content-type', 'application/octet-stream')
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self.redis.set(self.key('mime', url), mime, px=self.expire)
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self.redis.set(self.key('body', url), resp.content, px=self.expire)
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def respond(self, url):
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x_imgproxy_cache = 'HIT'
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mime = self.redis.get(self.key('mime', url))
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body = self.redis.get(self.key('body', url))
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if not body or not mime:
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x_imgproxy_cache = 'MISS'
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if self.redis.set(
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self.key('lock', url), 1, nx=True, ex=10*self.timeout):
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t = threading.Thread(target=self.fetch_and_cache, args=(url,))
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t.start()
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t.join(self.timeout)
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mime = self.redis.get(self.key('mime', url))
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body = self.redis.get(self.key('body', url))
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if not body or not mime:
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return abort(404)
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resp = make_response(body, 200)
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resp.headers.set('content-type', mime)
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resp.headers.set('x-imgproxy-cache', x_imgproxy_cache)
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return resp
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