First Commit

2026-05-31 10:17:09 +07:00
commit 17a9c69379
4547 changed files with 1170384 additions and 0 deletions
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+"""HTTP cache implementation."""
+
+from __future__ import annotations
+
+import os
+import shutil
+from collections.abc import Generator
+from contextlib import contextmanager
+from datetime import datetime
+from typing import Any, BinaryIO, Callable
+
+from pip._vendor.cachecontrol.cache import SeparateBodyBaseCache
+from pip._vendor.cachecontrol.caches import SeparateBodyFileCache
+from pip._vendor.requests.models import Response
+
+from pip._internal.utils.filesystem import (
+    adjacent_tmp_file,
+    copy_directory_permissions,
+    replace,
+)
+from pip._internal.utils.misc import ensure_dir
+
+
+def is_from_cache(response: Response) -> bool:
+    return getattr(response, "from_cache", False)
+
+
+@contextmanager
+def suppressed_cache_errors() -> Generator[None, None, None]:
+    """If we can't access the cache then we can just skip caching and process
+    requests as if caching wasn't enabled.
+    """
+    try:
+        yield
+    except OSError:
+        pass
+
+
+class SafeFileCache(SeparateBodyBaseCache):
+    """
+    A file based cache which is safe to use even when the target directory may
+    not be accessible or writable.
+
+    There is a race condition when two processes try to write and/or read the
+    same entry at the same time, since each entry consists of two separate
+    files (https://github.com/psf/cachecontrol/issues/324).  We therefore have
+    additional logic that makes sure that both files to be present before
+    returning an entry; this fixes the read side of the race condition.
+
+    For the write side, we assume that the server will only ever return the
+    same data for the same URL, which ought to be the case for files pip is
+    downloading.  PyPI does not have a mechanism to swap out a wheel for
+    another wheel, for example.  If this assumption is not true, the
+    CacheControl issue will need to be fixed.
+    """
+
+    def __init__(self, directory: str) -> None:
+        assert directory is not None, "Cache directory must not be None."
+        super().__init__()
+        self.directory = directory
+
+    def _get_cache_path(self, name: str) -> str:
+        # From cachecontrol.caches.file_cache.FileCache._fn, brought into our
+        # class for backwards-compatibility and to avoid using a non-public
+        # method.
+        hashed = SeparateBodyFileCache.encode(name)
+        parts = list(hashed[:5]) + [hashed]
+        return os.path.join(self.directory, *parts)
+
+    def get(self, key: str) -> bytes | None:
+        # The cache entry is only valid if both metadata and body exist.
+        metadata_path = self._get_cache_path(key)
+        body_path = metadata_path + ".body"
+        if not (os.path.exists(metadata_path) and os.path.exists(body_path)):
+            return None
+        with suppressed_cache_errors():
+            with open(metadata_path, "rb") as f:
+                return f.read()
+
+    def _write_to_file(self, path: str, writer_func: Callable[[BinaryIO], Any]) -> None:
+        """Common file writing logic with proper permissions and atomic replacement."""
+        with suppressed_cache_errors():
+            ensure_dir(os.path.dirname(path))
+
+            with adjacent_tmp_file(path) as f:
+                writer_func(f)
+                # Inherit the read/write permissions of the cache directory
+                # to enable multi-user cache use-cases.
+                copy_directory_permissions(self.directory, f)
+
+            replace(f.name, path)
+
+    def _write(self, path: str, data: bytes) -> None:
+        self._write_to_file(path, lambda f: f.write(data))
+
+    def _write_from_io(self, path: str, source_file: BinaryIO) -> None:
+        self._write_to_file(path, lambda f: shutil.copyfileobj(source_file, f))
+
+    def set(
+        self, key: str, value: bytes, expires: int | datetime | None = None
+    ) -> None:
+        path = self._get_cache_path(key)
+        self._write(path, value)
+
+    def delete(self, key: str) -> None:
+        path = self._get_cache_path(key)
+        with suppressed_cache_errors():
+            os.remove(path)
+        with suppressed_cache_errors():
+            os.remove(path + ".body")
+
+    def get_body(self, key: str) -> BinaryIO | None:
+        # The cache entry is only valid if both metadata and body exist.
+        metadata_path = self._get_cache_path(key)
+        body_path = metadata_path + ".body"
+        if not (os.path.exists(metadata_path) and os.path.exists(body_path)):
+            return None
+        with suppressed_cache_errors():
+            return open(body_path, "rb")
+
+    def set_body(self, key: str, body: bytes) -> None:
+        path = self._get_cache_path(key) + ".body"
+        self._write(path, body)
+
+    def set_body_from_io(self, key: str, body_file: BinaryIO) -> None:
+        """Set the body of the cache entry from a file object."""
+        path = self._get_cache_path(key) + ".body"
+        self._write_from_io(path, body_file)