111 lines
3.7 KiB
Python
111 lines
3.7 KiB
Python
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# (c) 2005 Ian Bicking and contributors; written for Paste (http://pythonpaste.org)
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# Licensed under the MIT license: http://www.opensource.org/licenses/mit-license.php
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# (c) 2005 Ian Bicking and contributors; written for Paste (http://pythonpaste.org)
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# Licensed under the MIT license: http://www.opensource.org/licenses/mit-license.php
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"""
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WSGI middleware
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Gzip-encodes the response.
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"""
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import gzip
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from paste.response import header_value, remove_header
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from paste.httpheaders import CONTENT_LENGTH
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import six
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class GzipOutput(object):
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pass
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class middleware(object):
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def __init__(self, application, compress_level=6):
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self.application = application
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self.compress_level = int(compress_level)
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def __call__(self, environ, start_response):
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if 'gzip' not in environ.get('HTTP_ACCEPT_ENCODING', '') \
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or environ['REQUEST_METHOD'] == 'HEAD':
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# nothing for us to do, so this middleware will
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# be a no-op (there's no body expected in the HEAD case,
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# and if we open a GzipFile we would produce an erroneous
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# 20-byte header and trailer):
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return self.application(environ, start_response)
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response = GzipResponse(start_response, self.compress_level)
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app_iter = self.application(environ,
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response.gzip_start_response)
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if app_iter is not None:
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response.finish_response(app_iter)
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return response.write()
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class GzipResponse(object):
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def __init__(self, start_response, compress_level):
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self.start_response = start_response
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self.compress_level = compress_level
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self.buffer = six.BytesIO()
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self.compressible = False
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self.content_length = None
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def gzip_start_response(self, status, headers, exc_info=None):
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self.headers = headers
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ct = header_value(headers,'content-type')
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ce = header_value(headers,'content-encoding')
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self.compressible = False
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if ct and (ct.startswith('text/') or ct.startswith('application/')) \
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and 'zip' not in ct:
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self.compressible = True
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if ce:
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self.compressible = False
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if self.compressible:
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headers.append(('content-encoding', 'gzip'))
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remove_header(headers, 'content-length')
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self.headers = headers
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self.status = status
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return self.buffer.write
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def write(self):
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out = self.buffer
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out.seek(0)
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s = out.getvalue()
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out.close()
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return [s]
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def finish_response(self, app_iter):
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if self.compressible:
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output = gzip.GzipFile(mode='wb', compresslevel=self.compress_level,
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fileobj=self.buffer)
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else:
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output = self.buffer
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try:
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for s in app_iter:
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output.write(s)
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if self.compressible:
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output.close()
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finally:
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if hasattr(app_iter, 'close'):
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app_iter.close()
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content_length = self.buffer.tell()
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CONTENT_LENGTH.update(self.headers, content_length)
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self.start_response(self.status, self.headers)
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def filter_factory(application, **conf):
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import warnings
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warnings.warn(
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'This function is deprecated; use make_gzip_middleware instead',
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DeprecationWarning, 2)
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def filter(application):
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return middleware(application)
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return filter
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def make_gzip_middleware(app, global_conf, compress_level=6):
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"""
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Wrap the middleware, so that it applies gzipping to a response
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when it is supported by the browser and the content is of
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type ``text/*`` or ``application/*``
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"""
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compress_level = int(compress_level)
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return middleware(app, compress_level=compress_level)
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