gitfilter

This library eventually will be used in mgt

This library gives you low level access to the output of git-fast-export

It is designed to quickly parse the output of git-fast-export into structured object which you as the user can then manipulate or filter before passing the output back to some stream.

This stream is meant to eventually be passed into git-fast-import which will let you rewrite your git repository history very quickly. This is a very flexible approach because you get access to all commits very quickly, and you can do complicated things such as renaming files/folders, excluding commits, changing times, applying transformations to files, etc, etc.

This library is still a work in progress, but extremely basic functionality works:

// this example will use the `filter_with_cb` function that
// takes a writable stream, and a callback.
// the writable stream in this case is just standard out
// and we give a callback which will filter out any
// commits where the email address of the committer
// contains "jerry"

use gitfilter::export_parser;
use gitfilter::filter;
use export_parser::StructuredExportObject;
use export_parser::StructuredObjectType;
use std::io::Write;
use std::io::stdout;
use std::io;

fn filter_path_works() {
    let writer = stdout();
    filter_with_cb(writer, |obj| {
        match &obj.object_type {
            StructuredObjectType::Blob(_) => true,
            StructuredObjectType::Commit(commit_obj) => {
                if commit_obj.committer.email.contains("jerry") {
                    false
                } else {
                    true
                }
            }
        }
    }).unwrap();
}

This library is heavily inspired from git-filter-repo

This library aims to be a subset of git-filter-repo, particularly I don't plan on handling tags, or making a robust CLI for it. Instead, I wrote gitfilter because I wanted to use git-filter-repo in an advanced way, but git-filter-repo is written in python and is a bit slow for my use case, and it requires you to pass in python code as a string for some advanced features. This makes it not very ergonomic for my use case. Additionally, since it is written in python, I am currently listing this as an external dependency in my mgt project, but it would be more convenient for users if this filtering functionality was present directly in the mgt binary.