forget-cancellare-vecchi-toot/lib/brotli.py

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import brotli as brotli_
from flask import request, make_response
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from threading import Thread
from hashlib import sha256
import redis
import os.path
import mimetypes
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class BrotliCache(object):
def __init__(self, redis_kwargs={}, max_wait=0.020, expire=60*60*6):
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self.redis = redis.StrictRedis(**redis_kwargs)
self.max_wait = max_wait
self.expire = expire
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self.redis.client_setname('brotlicache')
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def compress(self, cache_key, lock_key, body, mode=brotli_.MODE_GENERIC):
encbody = brotli_.compress(body, mode=mode)
self.redis.set(cache_key, encbody, ex=self.expire)
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self.redis.delete(lock_key)
def wrap_response(self, response):
if 'br' not in request.accept_encodings or response.is_streamed:
return response
body = response.get_data()
digest = sha256(body).hexdigest()
cache_key = 'brotlicache:{}'.format(digest)
encbody = self.redis.get(cache_key)
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response.headers.set('x-brotli-cache', 'HIT')
if not encbody:
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response.headers.set('x-brotli-cache', 'MISS')
lock_key = 'brotlicache:lock:{}'.format(digest)
if self.redis.set(lock_key, 1, nx=True, ex=10):
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mode = (
brotli_.MODE_TEXT
if response.content_type.startswith('text/')
else brotli_.MODE_GENERIC)
t = Thread(
target=self.compress,
args=(cache_key, lock_key, body, mode))
t.start()
if self.max_wait > 0:
t.join(self.max_wait)
encbody = self.redis.get(cache_key)
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if not encbody:
response.headers.set('x-brotli-cache', 'TIMEOUT')
else:
response.headers.set('x-brotli-cache', 'LOCKED')
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if encbody:
response.headers.set('content-encoding', 'br')
response.headers.set('vary', 'accept-encoding')
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response.set_data(encbody)
return response
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return response
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def brotli(app, static=True, dynamic=True):
original_static = app.view_functions['static']
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def static_maybe_gzip_brotli(filename=None):
path = os.path.join(app.static_folder, filename)
for encoding, extension in (('br', '.br'), ('gzip', '.gz')):
if encoding not in request.accept_encodings:
continue
encpath = path + extension
if os.path.isfile(encpath):
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resp = make_response(
original_static(filename=filename + extension))
resp.headers.set('content-encoding', encoding)
resp.headers.set('vary', 'accept-encoding')
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mimetype = (mimetypes.guess_type(filename)[0]
or 'application/octet-stream')
resp.headers.set('content-type', mimetype)
return resp
return original_static(filename=filename)
if static:
app.view_functions['static'] = static_maybe_gzip_brotli
if dynamic:
cache = BrotliCache()
app.after_request(cache.wrap_response)