tvl-depot/tvix/store
Florian Klink ff40332864 refactor(tvix/store/nar/import): add ingest_nar_and_hash
This wraps ingest_nar, but also keeps track of the number of bytes read,
and calculates the sha256 digest of it.

Make use of it in the NixHTTPPathInfoService, where this code is coming
from.

Change-Id: I9c54e93d3ec8ed9ede87aed43e04d114fb06897b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11787
Reviewed-by: Connor Brewster <cbrewster@hey.com>
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2024-06-11 22:47:31 +00:00
..
docs docs(tvix): fix some typos across various documents 2024-06-08 21:17:56 +00:00
protos refactor(tvix/*/protos): separate lint target 2023-12-11 22:35:39 +00:00
src refactor(tvix/store/nar/import): add ingest_nar_and_hash 2024-06-11 22:47:31 +00:00
build.rs fix(tvix): don't emit rerun-if-changed 2024-03-16 09:34:10 +00:00
Cargo.toml feat(tvix/tracing): introduce common tvix-tracing crate 2024-06-10 16:35:08 +00:00
default.nix feat(tvix): add CI targets for checking crate features powerset 2024-06-03 16:35:51 +00:00
README.md fix(tvix/store): rename Read method in Readme 2023-09-26 15:24:32 +00:00

//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.