Pure OCaml low-level bindings to Git -- Guaranteed no C inside.
Support for on-disk and in-memory Git stores. Can read and write all the Git objects: the usual blobs, trees, commits and tags but also the pack files, pack indexes and the index file (where the staging area lives).
All the objects share a consistent API, and convenience functions are provided to manipulate the different objects. For instance, it is possible to make a pack file position independent (as the Zlib compression might change the relative offsets between the packed objects), to generate pack indexes from pack files, or to expand the filesystem of a given commit.
The library comes with a command-line tool called
ogit which shares
a similar interface with
git, but where all operations are mapped to
the API exposed
ocaml-git (and hence using only OCaml code).
The API documentation is available online.
Build and Install Instructions
To build and install the project, simply run:
$ opam install git
What is supported
The loose object files can be read and written;
binary blobs (files)
- trees (directories)
commits (revision history)
The pack files and pack indexes (which are collections of compressed loose objects using a diff-based representation) can be read and written). Moreover, diff hunks are exposed using a higher-level position-independent representation so that they can be manipulated more easily.
The index file (cache) -- used as for managing the stagging area -- is fully supported. Which means that
git statuswill work as expected on a repository created by the library.
Basic support for client-side cloning and fetching (using bare and deepen options) but with no support for fancy download capabilities which is exposed by usual Git servers.
What is not supported
Only client-side operations are currently supported. Implementing the corresponding server-side implementation is high on the TODO list: using a dummy compression scheme, this should not be too hard to add, though.
Merging and rebasing strategies are not supported.
Performance is comparable to the
git command. For instance, when
downloading and processing a 5.4MiB pack file (the download time
itself takes ~10s):
$ time ogit clone git://github.com/ocaml/opam-repository Cloning into 'opam-repository' ... Receiving data ... done. Resolving deltas: 100% (37294/37294), done. remote: Counting objects: 37294, done. Checking out files: 100% (6527/6527), done. HEAD is now at 267e08725291fc61b8411c0f20553ddd2e246d4f real 0m22.522s user 0m4.954s sys 0m5.078s
$ time git clone git://github.com/ocaml/opam-repository Cloning into 'opam-repository'... remote: Reusing existing pack: 37868, done. remote: Total 37868 (delta 0), reused 0 (delta 0) Receiving objects: 100% (37868/37868), 5.41 MiB | 408.00 KiB/s, done. Resolving deltas: 100% (13973/13973), done. Checking connectivity... done real 0m17.409s user 0m1.198s sys 0m0.925s
Not much energy have been dedicated to profiling the protocol implementation yet, so there is still plenty room for improvement.