60 lines
1.7 KiB
Python
60 lines
1.7 KiB
Python
|
"""
|
||
|
|
Move a file in the safest way possible::
|
||
|
|
|
||
|
|
>>> from django.core.files.move import file_move_save
|
||
|
|
>>> file_move_save("/tmp/old_file", "/tmp/new_file")
|
||
|
|
"""
|
||
|
|
|
||
|
|
import os
|
||
|
|
from django.core.files import locks
|
||
|
|
|
||
|
|
__all__ = ['file_move_safe']
|
||
|
|
|
||
|
|
try:
|
||
|
|
import shutil
|
||
|
|
file_move = shutil.move
|
||
|
|
except ImportError:
|
||
|
|
file_move = os.rename
|
||
|
|
|
||
|
|
def file_move_safe(old_file_name, new_file_name, chunk_size = 1024*64, allow_overwrite=False):
|
||
|
|
"""
|
||
|
|
Moves a file from one location to another in the safest way possible.
|
||
|
|
|
||
|
|
First, try using ``shutils.move``, which is OS-dependent but doesn't break
|
||
|
|
if moving across filesystems. Then, try ``os.rename``, which will break
|
||
|
|
across filesystems. Finally, streams manually from one file to another in
|
||
|
|
pure Python.
|
||
|
|
|
||
|
|
If the destination file exists and ``allow_overwrite`` is ``False``, this
|
||
|
|
function will throw an ``IOError``.
|
||
|
|
"""
|
||
|
|
|
||
|
|
# There's no reason to move if we don't have to.
|
||
|
|
if old_file_name == new_file_name:
|
||
|
|
return
|
||
|
|
|
||
|
|
if not allow_overwrite and os.path.exists(new_file_name):
|
||
|
|
raise IOError("Cannot overwrite existing file '%s'." % new_file_name)
|
||
|
|
|
||
|
|
try:
|
||
|
|
file_move(old_file_name, new_file_name)
|
||
|
|
return
|
||
|
|
except OSError:
|
||
|
|
# This will happen with os.rename if moving to another filesystem
|
||
|
|
pass
|
||
|
|
|
||
|
|
# If the built-in didn't work, do it the hard way.
|
||
|
|
new_file = open(new_file_name, 'wb')
|
||
|
|
locks.lock(new_file, locks.LOCK_EX)
|
||
|
|
old_file = open(old_file_name, 'rb')
|
||
|
|
current_chunk = None
|
||
|
|
|
||
|
|
while current_chunk != '':
|
||
|
|
current_chunk = old_file.read(chunk_size)
|
||
|
|
new_file.write(current_chunk)
|
||
|
|
|
||
|
|
new_file.close()
|
||
|
|
old_file.close()
|
||
|
|
|
||
|
|
os.remove(old_file_name)
|