History

Florian Klink 28b692fd50 feat(tvix/tvix-store): improve progress bars Don't show an empty spinner for daemon commands. Move the bar to the right, so the text is better aligned between spinner progress and bar progress styles. Generally, push progress bars a bit more down to the place where we can track progress. This includes adding one in the upload_blob span. Introduce another progress style template for transfers, which interprets the counter as bytes (not just a plain integer), and also a data rate. Use it for here and in the fetching code, and also make the progress bar itself a bit less wide. Change-Id: I15c2ea3d2b24b5186cec19cd3dbd706638497f40 Reviewed-on: https://cl.tvl.fyi/c/depot/+/11845 Tested-by: BuildkiteCI Autosubmit: flokli <flokli@flokli.de> Reviewed-by: Simon Hauser <simon.hauser@helsinki-systems.de>		2024-06-17 12:57:34 +00:00
..
protos	refactor(tvix/*/protos): separate lint target	2023-12-11 22:35:39 +00:00
src	feat(tvix/tvix-store): improve progress bars	2024-06-17 12:57:34 +00:00
build.rs	fix(tvix): don't emit rerun-if-changed	2024-03-16 09:34:10 +00:00
Cargo.toml	feat(tvix/cli,store): add tracy feature	2024-06-15 05:24:37 +00:00
default.nix	chore(tvix/docs): move [ca]store docs to tvix/docs	2024-06-14 08:00:34 +00:00
README.md	fix(tvix/store): rename Read method in Readme	2023-09-26 15:24:32 +00:00

README.md

//tvix/store

This contains the code hosting the tvix-store.

For the local store, Nix realizes files on the filesystem in /nix/store (and maintains some metadata in a SQLite database). For "remote stores", it communicates this metadata in NAR (Nix ARchive) and NARInfo format.

Compared to the Nix model, tvix-store stores data on a much more granular level than that, which provides more deduplication possibilities, and more granular copying.

However, enough information is preserved to still be able to render NAR and NARInfo when needed.

More Information

The store consists out of two different gRPC services, tvix.castore.v1 for the low-level content-addressed bits, and tvix.store.v1 for the Nix and StorePath-specific bits.

Check the protos/ subfolder both here and in castore for the definition of the exact RPC methods and messages.

Interacting with the GRPC service manually

The shell environment in //tvix provides evans, which is an interactive REPL-based gPRC client.

You can use it to connect to a tvix-store and call the various RPC methods.

$ cargo run -- daemon &
$ evans --host localhost --port 8000 -r repl
  ______
 |  ____|
 | |__    __   __   __ _   _ __    ___
 |  __|   \ \ / /  / _. | | '_ \  / __|
 | |____   \ V /  | (_| | | | | | \__ \
 |______|   \_/    \__,_| |_| |_| |___/

 more expressive universal gRPC client


localhost:8000> package tvix.castore.v1
tvix.castore.v1@localhost:8000> service BlobService

tvix.castore.v1.BlobService@localhost:8000> call Put --bytes-from-file
data (TYPE_BYTES) => /run/current-system/system
{
  "digest": "KOM3/IHEx7YfInAnlJpAElYezq0Sxn9fRz7xuClwNfA="
}

tvix.castore.v1.BlobService@localhost:8000> call Read --bytes-as-base64
digest (TYPE_BYTES) => KOM3/IHEx7YfInAnlJpAElYezq0Sxn9fRz7xuClwNfA=
{
  "data": "eDg2XzY0LWxpbnV4"
}

$ echo eDg2XzY0LWxpbnV4 | base64 -d
x86_64-linux

Thanks to tvix-store providing gRPC Server Reflection (with reflection feature), you don't need to point evans to the .proto files.