Source code for django.middleware.gzip

from django.utils.cache import patch_vary_headers
from django.utils.deprecation import MiddlewareMixin
from django.utils.regex_helper import _lazy_re_compile
from django.utils.text import compress_sequence, compress_string

re_accepts_gzip = _lazy_re_compile(r"\bgzip\b")

[docs]class GZipMiddleware(MiddlewareMixin): """ Compress content if the browser allows gzip compression. Set the Vary header accordingly, so that caches will base their storage on the Accept-Encoding header. """ max_random_bytes = 100 def process_response(self, request, response): # It's not worth attempting to compress really short responses. if not response.streaming and len(response.content) < 200: return response # Avoid gzipping if we've already got a content-encoding. if response.has_header("Content-Encoding"): return response patch_vary_headers(response, ("Accept-Encoding",)) ae = request.META.get("HTTP_ACCEPT_ENCODING", "") if not return response if response.streaming: if response.is_async: # pull to lexical scope to capture fixed reference in case # streaming_content is set again later. orignal_iterator = response.streaming_content async def gzip_wrapper(): async for chunk in orignal_iterator: yield compress_string( chunk, max_random_bytes=self.max_random_bytes, ) response.streaming_content = gzip_wrapper() else: response.streaming_content = compress_sequence( response.streaming_content, max_random_bytes=self.max_random_bytes, ) # Delete the `Content-Length` header for streaming content, because # we won't know the compressed size until we stream it. del response.headers["Content-Length"] else: # Return the compressed content only if it's actually shorter. compressed_content = compress_string( response.content, max_random_bytes=self.max_random_bytes, ) if len(compressed_content) >= len(response.content): return response response.content = compressed_content response.headers["Content-Length"] = str(len(response.content)) # If there is a strong ETag, make it weak to fulfill the requirements # of RFC 9110 Section 8.8.1 while also allowing conditional request # matches on ETags. etag = response.get("ETag") if etag and etag.startswith('"'): response.headers["ETag"] = "W/" + etag response.headers["Content-Encoding"] = "gzip" return response
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