miniconda3/lib/python3.13/site-packages/conda/gateways/disk/test.py

# Copyright (C) 2012 Anaconda, Inc
# SPDX-License-Identifier: BSD-3-Clause
"""Disk utility functions testing path properties (e.g., writable, hardlinks, softlinks, etc.)."""

from functools import cache
from logging import getLogger
from os import W_OK, access
from os.path import basename, dirname, isdir, isfile, join
from uuid import uuid4

from ...base.constants import PREFIX_MAGIC_FILE
from ...common.constants import TRACE
from ...common.path import expand
from ...deprecations import deprecated
from ...models.enums import LinkType
from .create import create_link
from .delete import rm_rf
from .link import islink, lexists

log = getLogger(__name__)


def file_path_is_writable(path) -> bool:
    path = expand(path)
    log.log(TRACE, "checking path is writable %s", path)
    if isdir(dirname(path)):
        path_existed = lexists(path)
        try:
            fh = open(path, "a+")
        except OSError as e:
            log.debug(e)
            return False
        else:
            fh.close()
            if not path_existed:
                rm_rf(path)
            return True
    else:
        # TODO: probably won't work well on Windows
        return access(path, W_OK)


@cache
def hardlink_supported(source_file, dest_dir):
    test_file = join(dest_dir, f".tmp.{basename(source_file)}.{str(uuid4())[:8]}")
    if not isfile(source_file):
        raise OSError(f"Path {source_file} is not a file")
    if not isdir(dest_dir):
        raise OSError(f"Path {dest_dir} is not a directory")
    if lexists(test_file):
        rm_rf(test_file)
    if lexists(test_file):
        raise OSError(f"{test_file} should not exist anymore")
    try:
        # BeeGFS is a file system that does not support hard links between files in different
        # directories. Sometimes a soft link will be created with the hard link system call.
        create_link(source_file, test_file, LinkType.hardlink, force=True)
        is_supported = not islink(test_file)
        if is_supported:
            log.log(TRACE, "hard link supported for %s => %s", source_file, dest_dir)
        else:
            log.log(
                TRACE, "hard link IS NOT supported for %s => %s", source_file, dest_dir
            )
        return is_supported
    except OSError:
        log.log(TRACE, "hard link IS NOT supported for %s => %s", source_file, dest_dir)
        return False
    finally:
        rm_rf(test_file)


@cache
def softlink_supported(source_file, dest_dir):
    # On Windows, softlink creation is restricted to Administrative users by default. It can
    # optionally be enabled for non-admin users through explicit registry modification.
    log.log(TRACE, "checking soft link capability for %s => %s", source_file, dest_dir)
    test_path = join(dest_dir, ".tmp." + basename(source_file))
    if not isfile(source_file):
        raise OSError(f"Path {source_file} is not a file")
    if not isdir(dest_dir):
        raise OSError(f"Path {dest_dir} is not a directory")
    if lexists(test_path):
        raise OSError(f"{test_path} should not exist")
    try:
        create_link(source_file, test_path, LinkType.softlink, force=True)
        return islink(test_path)
    except OSError:
        return False
    finally:
        rm_rf(test_path)


@deprecated("25.9", "26.3", addendum="Use PrefixData.is_environment()")
def is_conda_environment(prefix):
    return isfile(join(prefix, PREFIX_MAGIC_FILE))