TimeoutAndRetrySession: fold in RateLimitAdapter and 429 retry (#6731)

Follow up to https://github.com/beetbox/beets/pull/6729

Move shared rate-limiting and 429 retry logic from the lyrics-specific
`LyricsSession` into the base `TimeoutAndRetrySession` so all plugins
benefit. Simplify `lyrics.py` by removing the now-redundant
`LyricsSession` subclass.

beetsplug/_utils/requests.py

@@ -78,15 +78,15 @@ class TimeoutAndRetrySession(requests.Session, metaclass=SingletonMeta):
         retry = Retry(
             total=6,
             backoff_factor=0.5,
-            # Retry on server errors
             status_forcelist=[
                 HTTPStatus.INTERNAL_SERVER_ERROR,
                 HTTPStatus.BAD_GATEWAY,
                 HTTPStatus.SERVICE_UNAVAILABLE,
                 HTTPStatus.GATEWAY_TIMEOUT,
+                HTTPStatus.TOO_MANY_REQUESTS,
             ],
         )
-        adapter = HTTPAdapter(max_retries=retry)
+        adapter = RateLimitAdapter(rate_limit=0.25, max_retries=retry)
         self.mount("https://", adapter)
         self.mount("http://", adapter)
 

beetsplug/lyrics.py

@@ -24,7 +24,6 @@ from contextlib import contextmanager, suppress
 from dataclasses import dataclass
 from functools import cached_property, partial, total_ordering
 from html import unescape
-from http import HTTPStatus
 from itertools import filterfalse, groupby
 from pathlib import Path
 from typing import TYPE_CHECKING, ClassVar, NamedTuple
@@ -33,7 +32,6 @@ from urllib.parse import quote, quote_plus, urlencode, urlparse
 import requests
 from bs4 import BeautifulSoup
 from unidecode import unidecode
-from urllib3.util.retry import Retry
 
 from beets import plugins, ui
 from beets.autotag import string_dist
@@ -45,7 +43,6 @@ from beets.util.lyrics import INSTRUMENTAL_LYRICS, Lyrics
 
 from ._utils.requests import (
     HTTPNotFoundError,
-    RateLimitAdapter,
     RequestHandler,
     TimeoutAndRetrySession,
 )
@@ -172,45 +169,12 @@ def slug(text: str) -> str:
     return re.sub(r"\W+", "-", unidecode(text).lower().strip()).strip("-")
 
 
-class LyricsSession(TimeoutAndRetrySession):
-    """HTTP session for lyrics backends with rate limiting and exponential backoff.
-
-    Builds on :class:`TimeoutAndRetrySession` — inherits User-Agent header,
-    default timeout, and response status checking. Adds a :class:`RateLimitAdapter`
-    to enforce a minimum interval between requests, and configures urllib3 Retry
-    with exponential backoff on rate limit (429) responses.
-    """
-
-    def __init__(self, rate_limit: float = 0.25):
-        """Initialize session with rate limiting and retry/backoff.
-
-        Args:
-            rate_limit: Minimum interval in seconds between consecutive
-                requests (default 0.25s = 4 requests/sec).
-        """
-        super().__init__()
-        retry = Retry(
-            total=6,
-            backoff_factor=1.0,
-            status_forcelist=[
-                HTTPStatus.INTERNAL_SERVER_ERROR,
-                HTTPStatus.BAD_GATEWAY,
-                HTTPStatus.SERVICE_UNAVAILABLE,
-                HTTPStatus.GATEWAY_TIMEOUT,
-                HTTPStatus.TOO_MANY_REQUESTS,
-            ],
-        )
-        adapter = RateLimitAdapter(rate_limit=rate_limit, max_retries=retry)
-        self.mount("https://", adapter)
-        self.mount("http://", adapter)
-
-
 class LyricsRequestHandler(RequestHandler):
     _log: Logger
 
     def create_session(self) -> TimeoutAndRetrySession:
         """Return a rate-limited session for lyrics HTTP requests."""
-        return LyricsSession()
+        return TimeoutAndRetrySession()
 
     def status_to_error(self, code: int) -> type[requests.HTTPError] | None:
         if err := super().status_to_error(code):

docs/changelog.rst

@@ -96,6 +96,10 @@ For plugin developers
 Other changes
 ~~~~~~~~~~~~~
 
+- :doc:`plugins/lyrics`: Fold rate limiting and 429 retry from the
+  lyrics-specific ``LyricsSession`` into the shared
+  :class:`~beetsplug._utils.requests.TimeoutAndRetrySession` so all plugins
+  benefit. The standalone ``LyricsSession`` class has been removed.
 - :doc:`plugins/spotify`: ``spotifysync`` now batches its SQLite commit for a
   sync run, follows the standard beets write-before-store pattern, and logs
   audio-features API unavailability only once per run.