feat: cache simple repository pages (#6932)

At #5868, I
[suggested](#5868 (comment))
that some of the caching that was being reworked could be removed
altogether, because cachecontrol was already taking care of it just
fine.

But now I find myself using an Azure artifacts repository, and it is
returning headers that insist that the client does not do any caching:
```
cache-control: no-cache
pragma: no-cache           
x-cache: CONFIG_NOCACHE 
```
(pypi, by contrast, sets max-age to 10 minutes here).

So I was wrong! And now I am seeing a big performance hit in some
projects where the solve involves overrides and backtracking: and
therefore hitting the legacy simple API repeatedly.

However, we don't need all the mechanism of cachy and its like for this,
a well-placed `@lru_cache()` seems more than sufficient.

This makes me wonder whether it wouldn't be better to do similar for
pypi anyway, and rip out cachecontrol altogether. But let's keep it
simple for now: this is an easy fix to a performance regression.

src/poetry/repositories/http_repository.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import functools
 import hashlib
 import os
 import urllib
@@ -50,6 +51,7 @@ def __init__(
             disable_cache=disable_cache,
         )
         self._authenticator.add_repository(name, url)
+        self.get_page = functools.lru_cache(maxsize=None)(self._get_page)
 
     @property
     def session(self) -> Authenticator:

src/poetry/repositories/legacy_repository.py

@@ -72,7 +72,7 @@ def package(
             return package
 
     def find_links_for_package(self, package: Package) -> list[Link]:
-        page = self._get_page(f"/{package.name}/")
+        page = self.get_page(f"/{package.name}/")
         if page is None:
             return []
 
@@ -90,7 +90,7 @@ def _find_packages(
         if not constraint.is_any():
             key = f"{key}:{constraint!s}"
 
-        page = self._get_page(f"/{name}/")
+        page = self.get_page(f"/{name}/")
         if page is None:
             self._log(
                 f"No packages found for {name}",
@@ -119,7 +119,7 @@ def _find_packages(
     def _get_release_info(
         self, name: NormalizedName, version: Version
     ) -> dict[str, Any]:
-        page = self._get_page(f"/{name}/")
+        page = self.get_page(f"/{name}/")
         if page is None:
             raise PackageNotFound(f'No package named "{name}"')
 

tests/repositories/test_legacy_repository.py

@@ -73,7 +73,7 @@ def test_packages_property_returns_empty_list() -> None:
 def test_page_relative_links_path_are_correct() -> None:
     repo = MockRepository()
 
-    page = repo._get_page("/relative")
+    page = repo.get_page("/relative")
     assert page is not None
 
     for link in page.links:
@@ -84,7 +84,7 @@ def test_page_relative_links_path_are_correct() -> None:
 def test_page_absolute_links_path_are_correct() -> None:
     repo = MockRepository()
 
-    page = repo._get_page("/absolute")
+    page = repo.get_page("/absolute")
     assert page is not None
 
     for link in page.links:
@@ -95,7 +95,7 @@ def test_page_absolute_links_path_are_correct() -> None:
 def test_page_clean_link() -> None:
     repo = MockRepository()
 
-    page = repo._get_page("/relative")
+    page = repo.get_page("/relative")
     assert page is not None
 
     cleaned = page.clean_link('https://legacy.foo.bar/test /the"/cleaning\0')
@@ -105,7 +105,7 @@ def test_page_clean_link() -> None:
 def test_page_invalid_version_link() -> None:
     repo = MockRepository()
 
-    page = repo._get_page("/invalid-version")
+    page = repo.get_page("/invalid-version")
     assert page is not None
 
     links = list(page.links)
@@ -123,7 +123,7 @@ def test_page_invalid_version_link() -> None:
 
 def test_sdist_format_support() -> None:
     repo = MockRepository()
-    page = repo._get_page("/relative")
+    page = repo.get_page("/relative")
     assert page is not None
     bz2_links = list(filter(lambda link: link.ext == ".tar.bz2", page.links))
     assert len(bz2_links) == 1
@@ -490,7 +490,7 @@ def __init__(
 def test_get_200_returns_page(http: type[httpretty.httpretty]) -> None:
     repo = MockHttpRepository({"/foo": 200}, http)
 
-    assert repo._get_page("/foo")
+    assert repo.get_page("/foo")
 
 
 @pytest.mark.parametrize("status_code", [401, 403, 404])
@@ -499,14 +499,14 @@ def test_get_40x_and_returns_none(
 ) -> None:
     repo = MockHttpRepository({"/foo": status_code}, http)
 
-    assert repo._get_page("/foo") is None
+    assert repo.get_page("/foo") is None
 
 
 def test_get_5xx_raises(http: type[httpretty.httpretty]) -> None:
     repo = MockHttpRepository({"/foo": 500}, http)
 
     with pytest.raises(RepositoryError):
-        repo._get_page("/foo")
+        repo.get_page("/foo")
 
 
 def test_get_redirected_response_url(
@@ -524,7 +524,7 @@ def get_mock(
         return response
 
     monkeypatch.setattr(repo.session, "get", get_mock)
-    page = repo._get_page("/foo")
+    page = repo.get_page("/foo")
     assert page is not None
     assert page._url == "http://legacy.redirect.bar/foo/"
 
@@ -560,7 +560,7 @@ def test_authenticator_with_implicit_repository_configuration(
     )
 
     repo = LegacyRepository(name="source", url="https://foo.bar/simple", config=config)
-    repo._get_page("/foo")
+    repo.get_page("/foo")
 
     request = http.last_request()
 

tests/repositories/test_single_page_repository.py

@@ -35,7 +35,7 @@ def _download(self, url: str, dest: Path) -> None:
 def test_single_page_repository_get_page():
     repo = MockSinglePageRepository("jax_releases")
 
-    page = repo._get_page("/ignored")
+    page = repo.get_page("/ignored")
     links = list(page.links)
 
     assert len(links) == 21