# SPDX-FileCopyrightText: 2015 Eric Larson
#
# SPDX-License-Identifier: Apache-2.0
from __future__ import annotations
import io
from typing import IO, TYPE_CHECKING, Any, Mapping, cast
from pip._vendor import msgpack
from pip._vendor.requests.structures import CaseInsensitiveDict
from pip._vendor.urllib3 import HTTPResponse
if TYPE_CHECKING:
from pip._vendor.requests import PreparedRequest
class Serializer:
serde_version = "4"
def dumps(
self,
request: PreparedRequest,
response: HTTPResponse,
body: bytes | None = None,
) -> bytes:
response_headers: CaseInsensitiveDict[str] = CaseInsensitiveDict(
response.headers
)
if body is None:
# When a body isn't passed in, we'll read the response. We
# also update the response with a new file handler to be
# sure it acts as though it was never read.
body = response.read(decode_content=False)
response._fp = io.BytesIO(body) # type: ignore[attr-defined]
response.length_remaining = len(body)
data = {
"response": {
"body": body, # Empty bytestring if body is stored separately
"headers": {str(k): str(v) for k, v in response.headers.items()}, # type: ignore[no-untyped-call]
"status": response.status,
"version": response.version,
"reason": str(response.reason),
"decode_content": response.decode_content,
}
}
# Construct our vary headers
data["vary"] = {}
if "vary" in response_headers:
varied_headers = response_headers["vary"].split(",")
for header in varied_headers:
header = str(header).strip()
header_value = request.headers.get(header, None)
if header_value is not None:
header_value = str(header_value)
data["vary"][header] = header_value
return b",".join([f"cc={self.serde_version}".encode(), self.serialize(data)])
def serialize(self, data: dict[str, Any]) -> bytes:
return cast(bytes, msgpack.dumps(data, use_bin_type=True))
def loads(
self,
request: PreparedRequest,
data: bytes,
body_file: IO[bytes] | None = None,
) -> HTTPResponse | None:
# Short circuit if we've been given an empty set of data
if not data:
return None
# 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
verstr = ver.split(b"=", 1)[-1].decode("ascii")
# Dispatch to the actual load method for the given version
try:
return getattr(self, f"_loads_v{verstr}")(request, data, body_file) # type: ignore[no-any-return]
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 None
def prepare_response(
self,
request: PreparedRequest,
cached: Mapping[str, Any],
body_file: IO[bytes] | None = None,
) -> HTTPResponse | None:
"""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 None
# 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 None
body_raw = cached["response"].pop("body")
headers: CaseInsensitiveDict[str] = CaseInsensitiveDict(
data=cached["response"]["headers"]
)
if headers.get("transfer-encoding", "") == "chunked":
headers.pop("transfer-encoding")
cached["response"]["headers"] = headers
try:
body: IO[bytes]
if body_file is None:
body = io.BytesIO(body_raw)
else:
body = body_file
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"))
# Discard any `strict` parameter serialized by older version of cachecontrol.
cached["response"].pop("strict", None)
return HTTPResponse(body=body, preload_content=False, **cached["response"])
def _loads_v0(
self,
request: PreparedRequest,
data: bytes,
body_file: IO[bytes] | None = None,
) -> None:
# 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 None
def _loads_v1(
self,
request: PreparedRequest,
data: bytes,
body_file: IO[bytes] | None = None,
) -> HTTPResponse | None:
# The "v1" pickled cache format. This is no longer supported
# for security reasons, so we treat it as a miss.
return None
def _loads_v2(
self,
request: PreparedRequest,
data: bytes,
body_file: IO[bytes] | None = None,
) -> HTTPResponse | None:
# The "v2" compressed base64 cache format.
# This has been removed due to age and poor size/performance
# characteristics, so we treat it as a miss.
return None
def _loads_v3(
self,
request: PreparedRequest,
data: bytes,
body_file: IO[bytes] | None = None,
) -> None:
# 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 None
def _loads_v4(
self,
request: PreparedRequest,
data: bytes,
body_file: IO[bytes] | None = None,
) -> HTTPResponse | None:
try:
cached = msgpack.loads(data, raw=False)
except ValueError:
return None
return self.prepare_response(request, cached, body_file)