History

Connor Brewster 9019d8568e fix(tvix/store): Remove virtiofs from default features vhost-user-backend doesn't support macOS yet, so the virtiofs features will not work on macOS. This removes it as a default feature which makes `cargo build` work out of the box on macOS. The `virtiofs` feature is enabled for Linux when building via Nix, but if being built by cargo directly, the feature must be enabled via a cargo flag. Change-Id: I2aaca9582f8e3dbcf9ee5f1b9831d614909f3799 Reviewed-on: https://cl.tvl.fyi/c/depot/+/9555 Reviewed-by: flokli <flokli@flokli.de> Tested-by: BuildkiteCI Autosubmit: Connor Brewster <cbrewster@hey.com>		2023-10-07 02:34:00 +00:00
..
docs	docs(tvix/store): various improvements	2023-07-07 09:48:32 +00:00
protos	feat(tvix/store/protos): add Validate() method to pathinfo.go	2023-10-05 18:42:58 +00:00
src	refactor(tvix/store/proto): use NamedNode trait	2023-10-05 18:58:55 +00:00
build.rs	chore(tvix/[ca]store): allow building without tonic-reflection	2023-09-26 10:07:40 +00:00
Cargo.toml	fix(tvix/store): Remove virtiofs from default features	2023-10-07 02:34:00 +00:00
default.nix	fix(tvix/store): Remove virtiofs from default features	2023-10-07 02:34:00 +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.