File size: 3,341 Bytes
d3de7c1 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 | from __future__ import annotations
import enum
import os
import stat
import sys
from typing import Final
FILE_ATTRIBUTE_UNIX_EXTENSION: Final = 0x8000
# Attribute is a UINT32 integer value.
# From bit 0 to 15 are as same as Windows attributes.
# Bit 16 to 31 is used for storing unix attributes.
FILE_ATTRIBUTE_UNIX_SHIFT: Final = 16
FILE_ATTRIBUTE_WINDOWS_MASK: Final = 0xFFFF
class MemberType(enum.Enum):
FILE = enum.auto()
DIRECTORY = enum.auto()
SYMLINK = enum.auto()
@property
def unix_file_type_bits(self) -> int:
"""Get the stat S_IF* constant for this member type."""
member2stat = {
MemberType.FILE: stat.S_IFREG,
MemberType.DIRECTORY: stat.S_IFDIR,
MemberType.SYMLINK: stat.S_IFLNK,
}
return member2stat[self]
@property
def win32_file_attributes(self) -> int:
"""Get the default Windows FILE_ATTRIBUTE_* flags for this member type."""
# Useless getattr to suppress mypy because typeshed
# decided you would never need stat.FILE_ATTRIBUTE_*
# on non-Windows platforms.
# See: https://github.com/python/typeshed/issues/14865
member2stat: dict[MemberType, int] = {
MemberType.FILE: getattr(stat, "FILE_ATTRIBUTE_ARCHIVE"),
MemberType.DIRECTORY: getattr(stat, "FILE_ATTRIBUTE_DIRECTORY"),
MemberType.SYMLINK: getattr(stat, "FILE_ATTRIBUTE_ARCHIVE") | getattr(stat, "FILE_ATTRIBUTE_REPARSE_POINT"),
}
return member2stat[self]
def unix_extension_bits(self, fstat: os.stat_result | None = None, /) -> int:
"""Get the Unix extension bits (file type and permissions)."""
base = FILE_ATTRIBUTE_UNIX_EXTENSION | (self.unix_file_type_bits << FILE_ATTRIBUTE_UNIX_SHIFT)
if fstat is not None:
return base | (stat.S_IMODE(fstat.st_mode) << FILE_ATTRIBUTE_UNIX_SHIFT)
return base
def attributes(self, fstat: os.stat_result | None = None, /) -> int:
"""
Get platform-appropriate file attributes by combining Windows attributes
(bits 0-15) with Unix extensions (bits 16-31). Unix extensions are always
included, even on Windows, so downstream code can use stat.S_IS*() checks
without platform-specific logic. When no stat result is provided, synthesizes
default attributes suitable for in-memory files.
"""
if fstat is None:
# There are cases where we might not have the stat_result,
# like a file generated in memory. In this case, we synthesize
# a sensible default by combining basic Windows and Unix attributes.
return self.win32_file_attributes | self.unix_extension_bits()
if sys.platform == "win32":
# NOTE: We set Unix extensions bits on Windows so things behave the same
# everywhere. That way, downstream code can just use stat.S_IS*() checks
# without caring what platform the file came from.
if self is MemberType.FILE:
return stat.FILE_ATTRIBUTE_ARCHIVE | self.unix_extension_bits()
return fstat.st_file_attributes & FILE_ATTRIBUTE_WINDOWS_MASK | self.unix_extension_bits()
# Unix-like platforms
return self.win32_file_attributes | self.unix_extension_bits(fstat)
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