From ae8ec5c3f4cfc7f14783b4dd58c436a7ba168138 Mon Sep 17 00:00:00 2001 From: Anderson Bravalheri Date: Wed, 3 May 2023 13:18:46 +0100 Subject: Improve atomicity when writing PKG-INFO For the time being, when `setuptools.build_meta` is called, `egg_info.egg_base` is accidentally set to the project root between the several calls to the different build hooks. This means that if the hooks are called, they will try to overwrite `setuptools.egg-info/PKG-INFO`, and for a very short interval of time it will be an empty file. Another process may then try to simultaneously use `importlib.metadata` to list entry-points. However to sort entry-points, `importlib.metadata` will try to read the `Name` field in the `PKG-INFO/METADATA` files and will raise an error/warning if that file is empty. This commit tries to use `os.replace` to avoid having an empty PKG-INFO while `importlib.metadata` is used. --- setuptools/_core_metadata.py | 21 +++++++++++++++++++++ setuptools/monkey.py | 4 +++- 2 files changed, 24 insertions(+), 1 deletion(-) diff --git a/setuptools/_core_metadata.py b/setuptools/_core_metadata.py index 4b25b2f4..b8290f50 100644 --- a/setuptools/_core_metadata.py +++ b/setuptools/_core_metadata.py @@ -3,9 +3,12 @@ Handling of Core Metadata for Python packages (including reading and writing). See: https://packaging.python.org/en/latest/specifications/core-metadata/ """ +import os +import stat import textwrap from email import message_from_file from email.message import Message +from tempfile import NamedTemporaryFile from typing import Optional, List from distutils.util import rfc822_escape @@ -122,6 +125,24 @@ def single_line(val): return val +def write_pkg_info(self, base_dir): + """Write the PKG-INFO file into the release tree.""" + temp = "" + final = os.path.join(base_dir, 'PKG-INFO') + try: + # Use a temporary file while writing to avoid race conditions + # (e.g. `importlib.metadata` reading `.egg-info/PKG-INFO`): + with NamedTemporaryFile("w", encoding="utf-8", dir=base_dir, delete=False) as f: + temp = f.name + self.write_pkg_file(f) + permissions = stat.S_IMODE(os.lstat(temp).st_mode) + os.chmod(temp, permissions | stat.S_IRGRP | stat.S_IROTH) + os.replace(temp, final) # atomic operation. + finally: + if temp and os.path.exists(temp): + os.remove(temp) + + # Based on Python 3.5 version def write_pkg_file(self, file): # noqa: C901 # is too complex (14) # FIXME """Write the PKG-INFO format data to a file object.""" diff --git a/setuptools/monkey.py b/setuptools/monkey.py index 23a5832d..5154d4c7 100644 --- a/setuptools/monkey.py +++ b/setuptools/monkey.py @@ -100,7 +100,9 @@ def patch_all(): def _patch_distribution_metadata(): """Patch write_pkg_file and read_pkg_file for higher metadata standards""" - for attr in ('write_pkg_file', 'read_pkg_file', 'get_metadata_version'): + for attr in ( + 'write_pkg_info', 'write_pkg_file', 'read_pkg_file', 'get_metadata_version' + ): new_val = getattr(setuptools._core_metadata, attr) setattr(distutils.dist.DistributionMetadata, attr, new_val) -- cgit v1.2.1