You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
38 lines
1.3 KiB
38 lines
1.3 KiB
import os
|
|
import tempfile
|
|
import contextlib
|
|
from typing import Optional
|
|
|
|
|
|
class CallbackReader:
|
|
"""Wraps a file, but overrides the read method to also
|
|
call a callback function with the number of bytes read so far."""
|
|
def __init__(self, f, callback, *args):
|
|
self.f = f
|
|
self.callback = callback
|
|
self.cb_args = args
|
|
self.total_read = 0
|
|
|
|
def __getattr__(self, attr):
|
|
return getattr(self.f, attr)
|
|
|
|
def read(self, *args, **kwargs):
|
|
chunk = self.f.read(*args, **kwargs)
|
|
self.total_read += len(chunk)
|
|
self.callback(*self.cb_args, self.total_read)
|
|
return chunk
|
|
|
|
|
|
@contextlib.contextmanager
|
|
def atomic_write_in_dir(path: str, mode: str = 'w', buffering: int = -1, encoding: Optional[str] = None, newline: Optional[str] = None,
|
|
overwrite: bool = False):
|
|
"""Write to a file atomically using a temporary file in the same directory as the destination file."""
|
|
dir_name = os.path.dirname(path)
|
|
|
|
if not overwrite and os.path.exists(path):
|
|
raise FileExistsError(f"File '{path}' already exists. To overwrite it, set 'overwrite' to True.")
|
|
|
|
with tempfile.NamedTemporaryFile(mode=mode, buffering=buffering, encoding=encoding, newline=newline, dir=dir_name, delete=False) as tmp_file:
|
|
yield tmp_file
|
|
tmp_file_name = tmp_file.name
|
|
os.replace(tmp_file_name, path)
|
|
|