fstrans - Python module for filesystem transactions

Description

This module allows to manipulate some directory tree in safe way, making sure that in case of error tree would left intact, and no other process such as webserver would access partially modified tree (although you can use external programs from your script to work with tree)

It also serializes write tree access - if one program starts transaction with some directory, other one, if started, would wait for some time for it to complete.

Module is Unix-only. It heavily relies on hard links to quickly make copies of big trees.

As working tree is populated with symlinks from final tree, user should make sure that file is different in local copy before modifying it.

For this module provides following methods:

1. open - works just like builtin function open, but makes sure that original file would not be clobbered before commit.
2. putfile - safely replaces file in tree with other file
3. clonefile, clonetree - make exact copy of original file with link count = 1.

Installation

You can install released version with pip3 install fstrans. If you prefer cutting age software, recommended way is

python3 setup.py sdist
pip3 install ./dist/fstrans-1.0.tar.gz

Of course, you can install system-wide build your OS packages and so on. But if you are planning to do so, you probably don't need special instructions.

Testing

There is unittest-based test suite in the test directory.

Run

python3 setup.py test

to run test suite.