perf(web.utils): WebResponse: adopt propcache.cached_property

Signed-off-by: Rongrong <[email protected]>

requirements.txt

@@ -29,6 +29,7 @@ dnspython[idna]==2.7.0
 
 # utils
 yarl==1.16.0
+propcache==0.2.0
 colorlog==6.8.2
 APScheduler==3.10.4
 python-dotenv==1.0.1

src/web/utils.py

@@ -23,11 +23,12 @@
 import email.utils
 import feedparser
 from contextlib import suppress
-from dataclasses import dataclass, field
+from dataclasses import dataclass
 from datetime import datetime, timezone, timedelta
 from ipaddress import ip_address, ip_network
 from urllib.parse import urlparse
 from multidict import CIMultiDictProxy
+from propcache import cached_property
 
 from .. import env, log
 from ..i18n import i18n
@@ -136,99 +137,73 @@ def rfc_2822_8601_to_datetime(time_str: Optional[str]) -> Optional[datetime]:
 
 @dataclass
 class WebResponse:
+    AGE_REMAINING_CLAMP_MIN: ClassVar[int] = 0
+    AGE_REMAINING_CLAMP_MAX: ClassVar[int] = 3600  # 1 hour
+
     url: str  # redirected url
     ori_url: str  # original url
     content: Optional[AnyStr]
     headers: CIMultiDictProxy[str]
     status: int
     reason: Optional[str]
 
-    _now: Optional[datetime] = field(default=sentinel, init=False, repr=False, hash=False, compare=False)
-    _date: Optional[datetime] = field(default=sentinel, init=False, repr=False, hash=False, compare=False)
-    _last_modified: Optional[datetime] = field(default=sentinel, init=False, repr=False, hash=False, compare=False)
-    _max_age: Optional[int] = field(default=sentinel, init=False, repr=False, hash=False, compare=False)
-    _age: Optional[int] = field(default=sentinel, init=False, repr=False, hash=False, compare=False)
-    _age_remaining: Optional[int] = field(default=sentinel, init=False, repr=False, hash=False, compare=False)
-    _expires: Optional[datetime] = field(default=sentinel, init=False, repr=False, hash=False, compare=False)
-
-    _age_remaining_clamp: ClassVar[range] = range(0, 3600 + 1)  # 1 hour
-
-    @property
+    @cached_property
     def etag(self) -> Optional[str]:
-        return self.headers.get('ETag')
+        return self.headers.get('ETag') or None  # Prohibit empty string
 
-    @property
+    @cached_property
     def now(self) -> datetime:
-        if self._now is sentinel:
-            self._now = datetime.now(timezone.utc)
-        return self._now
+        return datetime.now(timezone.utc)
 
-    @now.setter
-    def now(self, value: datetime):
-        self._now = value
-
-    @property
+    @cached_property
     def date(self) -> datetime:
-        if self._date is sentinel:
-            self._date = rfc_2822_8601_to_datetime(self.headers.get('Date')) or self.now
-        return self._date
+        return rfc_2822_8601_to_datetime(self.headers.get('Date')) or self.now
 
-    @property
+    @cached_property
     def last_modified(self) -> datetime:
-        if self._last_modified is sentinel:
-            self._last_modified = rfc_2822_8601_to_datetime(self.headers.get('Last-Modified')) or self.date
-        return self._last_modified
+        return rfc_2822_8601_to_datetime(self.headers.get('Last-Modified')) or self.date
 
-    @property
+    @cached_property
     def max_age(self) -> Optional[int]:
-        if self._max_age is not sentinel:
-            return self._max_age
         cache_control = self.headers.get('Cache-Control', '').lower()
         if not cache_control:
-            self._max_age = None
+            return None
         elif 'no-cache' in cache_control or 'no-store' in cache_control:
-            self._max_age = 0
+            return 0
         elif max_age := cache_control.partition('max-age=')[2].partition(',')[0]:
             try:
-                self._max_age = int(max_age) if max_age else None
+                return int(max_age) if max_age else None
             except ValueError:
-                self._max_age = None
-        else:
-            self._max_age = None
-        return self._max_age
+                return None
+        return None
 
-    @property
+    @cached_property
     def age(self) -> Optional[int]:
-        if self._age is sentinel:
-            age = self.headers.get('Age')
-            try:
-                self._age = int(age) if age else None
-            except ValueError:
-                self._age = None
-        return self._age
+        age = self.headers.get('Age')
+        try:
+            return int(age) if age else None
+        except ValueError:
+            return None
 
-    @property
+    @cached_property
     def age_remaining(self) -> Optional[int]:
-        if self._age_remaining is sentinel:
-            if self.max_age is None:
-                self._age_remaining = None
-            else:
-                self._age_remaining = self.max_age - (self.age or 0)
-                if self._age_remaining < self._age_remaining_clamp.start:
-                    self._age_remaining = self._age_remaining_clamp.start
-                elif self._age_remaining > self._age_remaining_clamp.stop:
-                    self._age_remaining = self._age_remaining_clamp.stop
-        return self._age_remaining
-
-    @property
+        if self.max_age is None:
+            return None
+        else:
+            age_remaining = self.max_age - (self.age or 0)
+            if age_remaining < (clamp_min := self.AGE_REMAINING_CLAMP_MIN):
+                return clamp_min
+            elif age_remaining > (clamp_max := self.AGE_REMAINING_CLAMP_MAX):
+                return clamp_max
+            return age_remaining
+
+    @cached_property
     def expires(self) -> Optional[datetime]:
-        if self._expires is sentinel:
-            # max-age overrides Expires: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Expires
-            if self.age_remaining is None:
-                self._expires = rfc_2822_8601_to_datetime(self.headers.get('Expires'))
-            else:
-                self._expires = self.date + timedelta(seconds=self.age_remaining)
-        return self._expires
+        # max-age overrides Expires: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Expires
+        if self.age_remaining is None:
+            return rfc_2822_8601_to_datetime(self.headers.get('Expires'))
+        else:
+            return self.date + timedelta(seconds=self.age_remaining)
 
 
 @dataclass