gridlock is a lockfile manager similar to Niv and Nix flakes, but with no dependency on Nix. It provides Nix compatible hashes, but is not inherently tied to Nix, and is suitable for just keeping track of git hashes if that's your jam.
The purpose of gridlock is to enable projects to provide a good experience
for Nix users by offering lock files with Nix compatible structural hashes of
the inside of archives (thereby being able to use non-IFD fetching) without
requiring all maintainers to have Nix installed.
Nix has two kinds of fetchers for files, one of which is the builtin
builtins.fetchTree, builtins.fetchTarball, etc, and the other is
nixpkgs.fetchzip and friends. The difference is that the builtin fetchers are
instances of import-from-derivation (IFD), whereas the ones in nixpkgs
are fixed-output derivations. The fixed-output derivations are greatly
preferable since they can be parallelized (the fact that the builtins cannot is
a Nix limitation) but they require a known hash ahead of time.
NOTE:
gridlockis currently alpha quality software, and is currently missing some rather important planned features such as updating a full lockfile in one shot, or progrss bars.
» gridlock --lockfile gridlock.json init
» gridlock --lockfile gridlock.json add tree-sitter/tree-sitter-rust
Adding tree-sitter/tree-sitter-rust at master: f7fb205c424b0962de59b26b931fe484e1262b35
» gridlock --lockfile gridlock.json show
tree-sitter-rust
Branch: master
Rev: f7fb205c424b0962de59b26b931fe484e1262b35
Last updated: 2023-02-16 21:38:35
Web link: https://github.com/tree-sitter/tree-sitter-rust/tree/f7fb205c424b0962de59b26b931fe484e1262b35
I simply reimplemented(tm) the NAR file format, and then generate NAR files in-memory, then hash them. The efficiency of the NAR encoder is undoubtedly not the best, but it is currently Ok. Also, on systems with Nix, the archive will need to be downloaded twice, since it is not imported into the Nix store by gridlock (FIXME: possibly add this as a feature?).
Another creative design choice in gridlock compared to Niv and Nix flakes is
that gridlock uses git to interact with GitHub, and does not touch the
GitHub API, due to the very low unauthenticated rate limits of the GitHub API.
I suspect that the git protocol operations used by gridlock are not rate
limited in the same way.