mirror of https://github.com/morpheus65535/bazarr
245 lines
9.0 KiB
Python
245 lines
9.0 KiB
Python
|
|
# Authors: William Fagan
|
|
# Copyright (c) 2013-2017 William Fagan
|
|
# License: The MIT License (MIT)
|
|
|
|
import sys
|
|
import functools
|
|
from gzip import GzipFile
|
|
import zlib
|
|
from io import BytesIO
|
|
|
|
from collections import defaultdict
|
|
|
|
from flask import request, after_this_request, current_app
|
|
|
|
|
|
if sys.version_info[:2] == (2, 6):
|
|
class GzipFile(GzipFile):
|
|
""" Backport of context manager support for python 2.6"""
|
|
def __enter__(self):
|
|
if self.fileobj is None:
|
|
raise ValueError("I/O operation on closed GzipFile object")
|
|
return self
|
|
|
|
def __exit__(self, *args):
|
|
self.close()
|
|
|
|
|
|
class DictCache(object):
|
|
|
|
def __init__(self):
|
|
self.data = {}
|
|
|
|
def get(self, key):
|
|
return self.data.get(key)
|
|
|
|
def set(self, key, value):
|
|
self.data[key] = value
|
|
|
|
|
|
class Compress(object):
|
|
"""
|
|
The Compress object allows your application to use Flask-Compress.
|
|
|
|
When initialising a Compress object you may optionally provide your
|
|
:class:`flask.Flask` application object if it is ready. Otherwise,
|
|
you may provide it later by using the :meth:`init_app` method.
|
|
|
|
:param app: optional :class:`flask.Flask` application object
|
|
:type app: :class:`flask.Flask` or None
|
|
"""
|
|
def __init__(self, app=None):
|
|
"""
|
|
An alternative way to pass your :class:`flask.Flask` application
|
|
object to Flask-Compress. :meth:`init_app` also takes care of some
|
|
default `settings`_.
|
|
|
|
:param app: the :class:`flask.Flask` application object.
|
|
"""
|
|
self.app = app
|
|
if app is not None:
|
|
self.init_app(app)
|
|
|
|
def init_app(self, app):
|
|
defaults = [
|
|
('COMPRESS_MIMETYPES', [
|
|
'application/javascript', # Obsolete (RFC 9239)
|
|
'application/json',
|
|
'text/css',
|
|
'text/html',
|
|
'text/javascript',
|
|
'text/xml',
|
|
]),
|
|
('COMPRESS_LEVEL', 6),
|
|
('COMPRESS_BR_LEVEL', 4),
|
|
('COMPRESS_BR_MODE', 0),
|
|
('COMPRESS_BR_WINDOW', 22),
|
|
('COMPRESS_BR_BLOCK', 0),
|
|
('COMPRESS_DEFLATE_LEVEL', -1),
|
|
('COMPRESS_MIN_SIZE', 500),
|
|
('COMPRESS_CACHE_KEY', None),
|
|
('COMPRESS_CACHE_BACKEND', None),
|
|
('COMPRESS_REGISTER', True),
|
|
('COMPRESS_STREAMS', True),
|
|
('COMPRESS_ALGORITHM', ['br', 'gzip', 'deflate']),
|
|
]
|
|
|
|
for k, v in defaults:
|
|
app.config.setdefault(k, v)
|
|
|
|
backend = app.config['COMPRESS_CACHE_BACKEND']
|
|
self.cache = backend() if backend else None
|
|
self.cache_key = app.config['COMPRESS_CACHE_KEY']
|
|
|
|
algo = app.config['COMPRESS_ALGORITHM']
|
|
if isinstance(algo, str):
|
|
self.enabled_algorithms = [i.strip() for i in algo.split(',')]
|
|
else:
|
|
self.enabled_algorithms = list(algo)
|
|
|
|
if (app.config['COMPRESS_REGISTER'] and
|
|
app.config['COMPRESS_MIMETYPES']):
|
|
app.after_request(self.after_request)
|
|
|
|
def _choose_compress_algorithm(self, accept_encoding_header):
|
|
"""
|
|
Determine which compression algorithm we're going to use based on the
|
|
client request. The `Accept-Encoding` header may list one or more desired
|
|
algorithms, together with a "quality factor" for each one (higher quality
|
|
means the client prefers that algorithm more).
|
|
|
|
:param accept_encoding_header: Content of the `Accept-Encoding` header
|
|
:return: name of a compression algorithm (`gzip`, `deflate`, `br`) or `None` if
|
|
the client and server don't agree on any.
|
|
"""
|
|
# A flag denoting that client requested using any (`*`) algorithm,
|
|
# in case a specific one is not supported by the server
|
|
fallback_to_any = False
|
|
|
|
# Map quality factors to requested algorithm names.
|
|
algos_by_quality = defaultdict(set)
|
|
|
|
# Set of supported algorithms
|
|
server_algos_set = set(self.enabled_algorithms)
|
|
|
|
for part in accept_encoding_header.lower().split(','):
|
|
part = part.strip()
|
|
if ';q=' in part:
|
|
# If the client associated a quality factor with an algorithm,
|
|
# try to parse it. We could do the matching using a regex, but
|
|
# the format is so simple that it would be overkill.
|
|
algo = part.split(';')[0].strip()
|
|
try:
|
|
quality = float(part.split('=')[1].strip())
|
|
except ValueError:
|
|
quality = 1.0
|
|
else:
|
|
# Otherwise, use the default quality
|
|
algo = part
|
|
quality = 1.0
|
|
|
|
if algo == '*':
|
|
if quality > 0:
|
|
fallback_to_any = True
|
|
elif algo == 'identity': # identity means 'no compression asked'
|
|
algos_by_quality[quality].add(None)
|
|
elif algo in server_algos_set:
|
|
algos_by_quality[quality].add(algo)
|
|
|
|
# Choose the algorithm with the highest quality factor that the server supports.
|
|
#
|
|
# If there are multiple equally good options, choose the first supported algorithm
|
|
# from server configuration.
|
|
#
|
|
# If the server doesn't support any algorithm that the client requested but
|
|
# there's a special wildcard algorithm request (`*`), choose the first supported
|
|
# algorithm.
|
|
for _, viable_algos in sorted(algos_by_quality.items(), reverse=True):
|
|
if len(viable_algos) == 1:
|
|
return viable_algos.pop()
|
|
elif len(viable_algos) > 1:
|
|
for server_algo in self.enabled_algorithms:
|
|
if server_algo in viable_algos:
|
|
return server_algo
|
|
|
|
if fallback_to_any:
|
|
return self.enabled_algorithms[0]
|
|
return None
|
|
|
|
def after_request(self, response):
|
|
app = self.app or current_app
|
|
|
|
vary = response.headers.get('Vary')
|
|
if not vary:
|
|
response.headers['Vary'] = 'Accept-Encoding'
|
|
elif 'accept-encoding' not in vary.lower():
|
|
response.headers['Vary'] = '{}, Accept-Encoding'.format(vary)
|
|
|
|
accept_encoding = request.headers.get('Accept-Encoding', '')
|
|
chosen_algorithm = self._choose_compress_algorithm(accept_encoding)
|
|
|
|
if (chosen_algorithm is None or
|
|
response.mimetype not in app.config["COMPRESS_MIMETYPES"] or
|
|
response.status_code < 200 or
|
|
response.status_code >= 300 or
|
|
(response.is_streamed and app.config["COMPRESS_STREAMS"] is False)or
|
|
"Content-Encoding" in response.headers or
|
|
(response.content_length is not None and
|
|
response.content_length < app.config["COMPRESS_MIN_SIZE"])):
|
|
return response
|
|
|
|
response.direct_passthrough = False
|
|
|
|
if self.cache is not None:
|
|
key = self.cache_key(request)
|
|
compressed_content = self.cache.get(key)
|
|
if compressed_content is None:
|
|
compressed_content = self.compress(app, response, chosen_algorithm)
|
|
self.cache.set(key, compressed_content)
|
|
else:
|
|
compressed_content = self.compress(app, response, chosen_algorithm)
|
|
|
|
response.set_data(compressed_content)
|
|
|
|
response.headers['Content-Encoding'] = chosen_algorithm
|
|
response.headers['Content-Length'] = response.content_length
|
|
|
|
# "123456789" => "123456789:gzip" - A strong ETag validator
|
|
# W/"123456789" => W/"123456789:gzip" - A weak ETag validator
|
|
etag = response.headers.get('ETag')
|
|
if etag:
|
|
response.headers['ETag'] = '{0}:{1}"'.format(etag[:-1], chosen_algorithm)
|
|
|
|
return response
|
|
|
|
def compressed(self):
|
|
def decorator(f):
|
|
@functools.wraps(f)
|
|
def decorated_function(*args, **kwargs):
|
|
@after_this_request
|
|
def compressor(response):
|
|
return self.after_request(response)
|
|
return f(*args, **kwargs)
|
|
return decorated_function
|
|
return decorator
|
|
|
|
def compress(self, app, response, algorithm):
|
|
if algorithm == 'gzip':
|
|
gzip_buffer = BytesIO()
|
|
with GzipFile(mode='wb',
|
|
compresslevel=app.config['COMPRESS_LEVEL'],
|
|
fileobj=gzip_buffer) as gzip_file:
|
|
gzip_file.write(response.get_data())
|
|
return gzip_buffer.getvalue()
|
|
elif algorithm == 'deflate':
|
|
return zlib.compress(response.get_data(),
|
|
app.config['COMPRESS_DEFLATE_LEVEL'])
|
|
elif algorithm == 'br':
|
|
import brotli
|
|
return brotli.compress(response.get_data(),
|
|
mode=app.config['COMPRESS_BR_MODE'],
|
|
quality=app.config['COMPRESS_BR_LEVEL'],
|
|
lgwin=app.config['COMPRESS_BR_WINDOW'],
|
|
lgblock=app.config['COMPRESS_BR_BLOCK'])
|