Minor optimization: exclude redundant CachedResponse.cache_key and CachedHTTPResponse.headers from serialization, and set at runtime instead

2 files changed, 16 insertions, 9 deletions

diff --git a/requests_cache/models/raw_response.py b/requests_cache/models/raw_response.py
index 8275100..de2a8f6 100644
--- a/requests_cache/models/raw_response.py
+++ b/requests_cache/models/raw_response.py
@@ -1,5 +1,6 @@
 from io import BytesIO
 from logging import getLogger
+from typing import Mapping
 
 from attr import define, field, fields_dict
 from requests import Response
@@ -18,18 +19,20 @@ class CachedHTTPResponse(HTTPResponse):
     """
 
     decode_content: bool = field(default=None)
-    headers: HTTPHeaderDict = field(factory=dict)
+    headers: HTTPHeaderDict = None  # Not serialized; set in either init or CachedResponse post-init
     reason: str = field(default=None)
     request_url: str = field(default=None)
     status: int = field(default=0)
     strict: int = field(default=0)
     version: int = field(default=0)
 
-    def __init__(self, *args, body: bytes = None, **kwargs):
+    def __init__(self, *args, body: bytes = None, headers: Mapping = None, **kwargs):
         """First initialize via HTTPResponse, then via attrs"""
         kwargs = {k: v for k, v in kwargs.items() if v is not None}
         super().__init__(body=BytesIO(body or b''), preload_content=False, **kwargs)
+
         self._body = body
+        self.headers = HTTPHeaderDict(headers)
         self.__attrs_init__(*args, **kwargs)
 
     @classmethod
@@ -37,7 +40,8 @@ class CachedHTTPResponse(HTTPResponse):
         """Create a CachedHTTPResponse based on an original response"""
         # Copy basic attributes
         raw = original_response.raw
-        kwargs = {k: getattr(raw, k, None) for k in fields_dict(cls).keys()}
+        copy_attrs = list(fields_dict(cls).keys()) + ['headers']
+        kwargs = {k: getattr(raw, k, None) for k in copy_attrs}
 
         # Note: _request_url is not available in urllib <=1.21
         kwargs['request_url'] = getattr(raw, '_request_url', None)
diff --git a/requests_cache/models/response.py b/requests_cache/models/response.py
index 229fd6a..d7fa3df 100755
--- a/requests_cache/models/response.py
+++ b/requests_cache/models/response.py
@@ -6,6 +6,7 @@ from attr import define, field
 from requests import PreparedRequest, Response
 from requests.cookies import RequestsCookieJar
 from requests.structures import CaseInsensitiveDict
+from urllib3.response import HTTPHeaderDict
 
 from ..cache_control import ExpirationTime, get_expiration_datetime
 from . import CachedHTTPResponse, CachedRequest
@@ -23,24 +24,26 @@ class CachedResponse(Response):
 
     _content: bytes = field(default=None)
     _next: Optional[CachedRequest] = field(default=None)
-    url: str = field(default=None)
-    status_code: int = field(default=0)
-    cache_key: str = field(default=None)
+    cache_key: Optional[str] = None  # Not serialized; set by BaseCache.get_response()
     cookies: RequestsCookieJar = field(factory=RequestsCookieJar)
     created_at: datetime = field(factory=datetime.utcnow)
     elapsed: timedelta = field(factory=timedelta)
-    expires: Optional[datetime] = field(default=None)
     encoding: str = field(default=None)
-    headers: CaseInsensitiveDict = field(factory=dict)
+    expires: Optional[datetime] = field(default=None)
+    headers: CaseInsensitiveDict = field(factory=CaseInsensitiveDict)
     history: List['CachedResponse'] = field(factory=list)  # type: ignore
+    raw: CachedHTTPResponse = field(factory=CachedHTTPResponse, repr=False)
     reason: str = field(default=None)
     request: CachedRequest = field(factory=CachedRequest)  # type: ignore
-    raw: CachedHTTPResponse = field(factory=CachedHTTPResponse, repr=False)
+    status_code: int = field(default=0)
+    url: str = field(default=None)
 
     def __attrs_post_init__(self):
         """Re-initialize raw response body after deserialization"""
         if self.raw._body is None and self._content is not None:
             self.raw.reset(self._content)
+        if not self.raw.headers:
+            self.raw.headers = HTTPHeaderDict(self.headers)
 
     @classmethod
     def from_response(cls, original_response: Response, **kwargs):