# glance.api.middleware.gzip

# Source code for glance.api.middleware.gzip

    # Copyright 2013 Red Hat, Inc.
    # All Rights Reserved.
    #
    #    Licensed under the Apache License, Version 2.0 (the "License"); you may
    #    not use this file except in compliance with the License. You may obtain
    #    a copy of the License at
    #
    #         http://www.apache.org/licenses/LICENSE-2.0
    #
    #    Unless required by applicable law or agreed to in writing, software
    #    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
    #    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
    #    License for the specific language governing permissions and limitations
    #    under the License.

    """
    Use gzip compression if the client accepts it.
    """

    import re

    from oslo_log import log as logging

    from glance.common import wsgi
    from glance.i18n import _LI

    LOG = logging.getLogger(__name__)

    class GzipMiddleware(wsgi.Middleware):

        re_zip = re.compile(r'\bgzip\b')

        def __init__(self, app):
            LOG.info(_LI("Initialized gzip middleware"))
            super(GzipMiddleware, self).__init__(app)

        def process_response(self, response):
            request = response.request
            accept_encoding = request.headers.get('Accept-Encoding', '')

            if self.re_zip.search(accept_encoding):
                # NOTE(flaper87): Webob removes the content-md5 when
                # app_iter is called. We'll keep it and reset it later
                checksum = response.headers.get("Content-MD5")

                # NOTE(flaper87): We'll use lazy for images so
                # that they can be compressed without reading
                # the whole content in memory. Notice that using
                # lazy will set response's content-length to 0.
                content_type = response.headers.get("Content-Type", "")
                lazy = content_type == "application/octet-stream"

                # NOTE(flaper87): Webob takes care of the compression
                # process, it will replace the body either with a
                # compressed body or a generator - used for lazy com
                # pression - depending on the lazy value.
                #
                # Webob itself will set the Content-Encoding header.
                response.encode_content(lazy=lazy)

                if checksum:
                    response.headers['Content-MD5'] = checksum

            return response

this page last updated: 2026-08-19 03:42:39

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