You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

61 lines
1.7 KiB
Python

from typing import Sequence, Union
import os
import sys
from tempfile import NamedTemporaryFile
import urllib.request
from .verify import verify_file_digest
def __to_string_sequence(x: Union[str, Sequence[str]]) -> Sequence[str]:
if isinstance(x, str):
return (x,)
else:
return x
def __get_any(x: Union[str, Sequence[str]]) -> str:
if isinstance(x, str):
return x
else:
return x[0]
def __download_one(url: str, path: str) -> None:
print("download", url)
urllib.request.urlretrieve(url, path)
def __download(urls: Sequence[str], path: str) -> None:
for url in urls[:-1]:
try:
__download_one(url, path)
return
except:
print("download error:", sys.exc_info()[0])
__download_one(urls[-1], path)
def __download_and_verify_to(urls: Sequence[str], md5: str, path: str) -> None:
__download(urls, path)
if not verify_file_digest(path, md5):
raise RuntimeError("Digest mismatch")
def download_basename(urls: Union[str, Sequence[str]]) -> str:
return os.path.basename(__get_any(urls))
def download_and_verify(urls: Union[str, Sequence[str]], md5: str, parent_path: str) -> str:
"""Download a file, verify its MD5 checksum and return the local path."""
base = download_basename(urls)
os.makedirs(parent_path, exist_ok=True)
path = os.path.join(parent_path, base)
try:
if verify_file_digest(path, md5): return path
os.unlink(path)
except FileNotFoundError:
pass
with NamedTemporaryFile(dir=parent_path) as tmp:
__download_and_verify_to(__to_string_sequence(urls), md5, tmp.name)
os.link(tmp.name, path)
return path