# SPDX-License-Identifier: Apache-2.0

# SPDX-FileCopyrightText: Copyright The Lance Authors

import os

from pathlib import Path

def wipe_os_cache(dataset_uri: str):

if dataset_uri.startswith("/"):

path = dataset_uri

elif dataset_uri.startswith("file://"):

path = Path(dataset_uri.removeprefix("file://"))

else:

return

if not hasattr(os, "posix_fadvise"):

raise NotImplementedError("posix_fadvise not available on this platform")

POSIX_FADV_DONTNEED = 4 # Tell kernel we don't need this data in cache

directory = Path(path)

file_iterator = directory.rglob("*")

for filepath in file_iterator:

# Skip directories, symlinks, and non-regular files

if not filepath.is_file():

continue

with open(filepath, "rb") as f:

fd = f.fileno()

# offset=0, length=0 means drop entire file from cache

os.posix_fadvise(fd, 0, 0, POSIX_FADV_DONTNEED)