History

Florian Klink fdf9657654 fix(tvix): don't emit rerun-if-changed `build.rs` emits rerun-if-changed statements for all proto files, as well as all include paths we pass it. Unfortunately, due to protobufs include path rules, we need to specify the path to the depot root itself as an include path, at least when building impurely with `cargo`. This causes cargo to essentially always rebuild, as it also puts its own temporary files in there. Unfortunately, tonic-build does not chase down to individual .proto files that are included. Disable emitting these `rerun-if-changed` statements for now. This could cause cargo to not rebuild protos every time, causing stale data until the next local `cargo clean`, but considering the protos change not that frequently, and it'll immediately surface if trying to build via Nix (either locally or in CI), it's a good-enough compromise. Change-Id: Ifd279a2216222ef3fc0e70c5a2fe6f87997f562e Reviewed-on: https://cl.tvl.fyi/c/depot/+/11157 Autosubmit: flokli <flokli@flokli.de> Reviewed-by: sterni <sternenseemann@systemli.org> Tested-by: BuildkiteCI		2024-03-16 09:34:10 +00:00
..
docs	chore(tvix/castore): move data model docs to here	2023-11-02 09:08:20 +00:00
protos	refactor(tvix/*/protos): separate lint target	2023-12-11 22:35:39 +00:00
src	docs(tvix): fix some docstrings	2024-03-15 23:16:01 +00:00
build.rs	fix(tvix): don't emit rerun-if-changed	2024-03-16 09:34:10 +00:00
Cargo.toml	feat(tvix/store): use reqwests' rustls-native-roots feature	2024-03-03 15:32:38 +00:00
default.nix	feat(tvix/store): use reqwests' rustls-native-roots feature	2024-03-03 15:32:38 +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.