PSCP: Per-session checkpoint

PSCP is a brand-new way to make checkpoint in git repository efficiently. By logging the hash output by pscp.create(), you can git diff, git stash branch and git checkout using them whenever you want. PSCP is framework-agnostic, so can be used in any git repository.

PSCP inherits all strengths from git, which are very useful for study.

• Recycle unchanged objects
• Compression (zlib)
• Show differences using git diff a..b
• Checkout to, using git checkout
• Create branch from, using git stash branch. This restores staged files staged and unstaged files unstaged.

Besides, PSCP does make neither git log nor git stash list messy. You won't suffer from trivial tuning commits and too many stashes.

Requirements

• python 3.5+
• git

Installation

pip install pscp

Getting Started

Getting Started

Frequently Asked Questions

How does it work?

How PSCP Works

Does PSCP just save 'all' files?

No, PSCP saves git-tracked files only. For details, please refer to 2.2 Git Basics - Recording Changes to the Repository.

Tracking New Files

Use git add to stage, to track new files. Untracked files will not be added to the checkpoint.

Saving environment variables or argparse results?

You're supposed to write to any file and track them (using git add). Using json built-in library, it can be done easily.

import json

To save environment variables,

import os
json.dump(fp, dict(os.environ), indent=4)

To save argparse namespace,

json.dump(fp, vars(args), indent=4)

Any other data can be saved in same way.

Command Line Tool (TODO)

python -m pscp

pscp.create(return_head_on_nothing=True, return_format='abbrev', link=True)

Create per-session checkpoint.

• return_head_on_nothing: If True, return hash of HEAD when there are nothing changed compared to HEAD, otherwise, return None.
• return_format
  • abbrev, short: Return abbreviated hash.
  • long: Return just unabbreviated hash.
  • ref: Return refspec. Raises exception when link == False.
• link: See pscp.link() below.

pscp.link(hash, refspec=None)

Create reference. pscp.link() could be used to avoid pruning on garbage collection.

• hash: The hash to be referenced.
• refspec: If None, refs/pscp/{timestamp_ms} is used.

pscp.delete(refspec)

Delete pscp reference. Call pscp.gc() if you want.

• refspec: Target refspec to be deleted. timestamp_ms is also allowed.

pscp.gc(prune='now')

Run git gc --prune=<prune>.

pscp.push(refspec=None, repository='origin')

Push checkpoint to the remote repository.

• refspec: If None, all checkpoints are pushed.

pscp.fetch(refspec=None, refmap=None, repository='origin')

• refspec: If None, all checkpoints are fetched.
• refmap: If None, refs/pscp/*:refs/pscp/* is used.