--- a/lib/python3.8/site-packages/pip/_vendor/cachecontrol/serialize.py	Mon Jul 27 03:47:31 2020 -0400
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,188 +0,0 @@
-import base64
-import io
-import json
-import zlib
-
-from pip._vendor import msgpack
-from pip._vendor.requests.structures import CaseInsensitiveDict
-
-from .compat import HTTPResponse, pickle, text_type
-
-
-def _b64_decode_bytes(b):
-    return base64.b64decode(b.encode("ascii"))
-
-
-def _b64_decode_str(s):
-    return _b64_decode_bytes(s).decode("utf8")
-
-
-class Serializer(object):
-
-    def dumps(self, request, response, body=None):
-        response_headers = CaseInsensitiveDict(response.headers)
-
-        if body is None:
-            body = response.read(decode_content=False)
-
-            # NOTE: 99% sure this is dead code. I'm only leaving it
-            #       here b/c I don't have a test yet to prove
-            #       it. Basically, before using
-            #       `cachecontrol.filewrapper.CallbackFileWrapper`,
-            #       this made an effort to reset the file handle. The
-            #       `CallbackFileWrapper` short circuits this code by
-            #       setting the body as the content is consumed, the
-            #       result being a `body` argument is *always* passed
-            #       into cache_response, and in turn,
-            #       `Serializer.dump`.
-            response._fp = io.BytesIO(body)
-
-        # NOTE: This is all a bit weird, but it's really important that on
-        #       Python 2.x these objects are unicode and not str, even when
-        #       they contain only ascii. The problem here is that msgpack
-        #       understands the difference between unicode and bytes and we
-        #       have it set to differentiate between them, however Python 2
-        #       doesn't know the difference. Forcing these to unicode will be
-        #       enough to have msgpack know the difference.
-        data = {
-            u"response": {
-                u"body": body,
-                u"headers": dict(
-                    (text_type(k), text_type(v)) for k, v in response.headers.items()
-                ),
-                u"status": response.status,
-                u"version": response.version,
-                u"reason": text_type(response.reason),
-                u"strict": response.strict,
-                u"decode_content": response.decode_content,
-            }
-        }
-
-        # Construct our vary headers
-        data[u"vary"] = {}
-        if u"vary" in response_headers:
-            varied_headers = response_headers[u"vary"].split(",")
-            for header in varied_headers:
-                header = text_type(header).strip()
-                header_value = request.headers.get(header, None)
-                if header_value is not None:
-                    header_value = text_type(header_value)
-                data[u"vary"][header] = header_value
-
-        return b",".join([b"cc=4", msgpack.dumps(data, use_bin_type=True)])
-
-    def loads(self, request, data):
-        # Short circuit if we've been given an empty set of data
-        if not data:
-            return
-
-        # Determine what version of the serializer the data was serialized
-        # with
-        try:
-            ver, data = data.split(b",", 1)
-        except ValueError:
-            ver = b"cc=0"
-
-        # Make sure that our "ver" is actually a version and isn't a false
-        # positive from a , being in the data stream.
-        if ver[:3] != b"cc=":
-            data = ver + data
-            ver = b"cc=0"
-
-        # Get the version number out of the cc=N
-        ver = ver.split(b"=", 1)[-1].decode("ascii")
-
-        # Dispatch to the actual load method for the given version
-        try:
-            return getattr(self, "_loads_v{}".format(ver))(request, data)
-
-        except AttributeError:
-            # This is a version we don't have a loads function for, so we'll
-            # just treat it as a miss and return None
-            return
-
-    def prepare_response(self, request, cached):
-        """Verify our vary headers match and construct a real urllib3
-        HTTPResponse object.
-        """
-        # Special case the '*' Vary value as it means we cannot actually
-        # determine if the cached response is suitable for this request.
-        # This case is also handled in the controller code when creating
-        # a cache entry, but is left here for backwards compatibility.
-        if "*" in cached.get("vary", {}):
-            return
-
-        # Ensure that the Vary headers for the cached response match our
-        # request
-        for header, value in cached.get("vary", {}).items():
-            if request.headers.get(header, None) != value:
-                return
-
-        body_raw = cached["response"].pop("body")
-
-        headers = CaseInsensitiveDict(data=cached["response"]["headers"])
-        if headers.get("transfer-encoding", "") == "chunked":
-            headers.pop("transfer-encoding")
-
-        cached["response"]["headers"] = headers
-
-        try:
-            body = io.BytesIO(body_raw)
-        except TypeError:
-            # This can happen if cachecontrol serialized to v1 format (pickle)
-            # using Python 2. A Python 2 str(byte string) will be unpickled as
-            # a Python 3 str (unicode string), which will cause the above to
-            # fail with:
-            #
-            #     TypeError: 'str' does not support the buffer interface
-            body = io.BytesIO(body_raw.encode("utf8"))
-
-        return HTTPResponse(body=body, preload_content=False, **cached["response"])
-
-    def _loads_v0(self, request, data):
-        # The original legacy cache data. This doesn't contain enough
-        # information to construct everything we need, so we'll treat this as
-        # a miss.
-        return
-
-    def _loads_v1(self, request, data):
-        try:
-            cached = pickle.loads(data)
-        except ValueError:
-            return
-
-        return self.prepare_response(request, cached)
-
-    def _loads_v2(self, request, data):
-        try:
-            cached = json.loads(zlib.decompress(data).decode("utf8"))
-        except (ValueError, zlib.error):
-            return
-
-        # We need to decode the items that we've base64 encoded
-        cached["response"]["body"] = _b64_decode_bytes(cached["response"]["body"])
-        cached["response"]["headers"] = dict(
-            (_b64_decode_str(k), _b64_decode_str(v))
-            for k, v in cached["response"]["headers"].items()
-        )
-        cached["response"]["reason"] = _b64_decode_str(cached["response"]["reason"])
-        cached["vary"] = dict(
-            (_b64_decode_str(k), _b64_decode_str(v) if v is not None else v)
-            for k, v in cached["vary"].items()
-        )
-
-        return self.prepare_response(request, cached)
-
-    def _loads_v3(self, request, data):
-        # Due to Python 2 encoding issues, it's impossible to know for sure
-        # exactly how to load v3 entries, thus we'll treat these as a miss so
-        # that they get rewritten out as v4 entries.
-        return
-
-    def _loads_v4(self, request, data):
-        try:
-            cached = msgpack.loads(data, raw=False)
-        except ValueError:
-            return
-
-        return self.prepare_response(request, cached)