tvl-depot/tvix/store
Florian Klink aaf258f61e feat(tvix/store): use async nar reader for ingest_nar
Rename read_nar to ingest_nar, and have it use the async nar reader
version, and the ingest_entries machinery.

This means we can now drop all code dealing with manually assembling
castore nodes.

Update our consumer, NixHTTPPathInfoService to use the new API.
As we now accept an AsyncRead, we don't need to do any blocking here
anymore, and can use the same async-compression crate as in the fetching
logic (and support some more compression formats out of the box).

Change-Id: I8646d20bd8603f8da47b5c84bc9e4ac236eb7f1a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11580
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: Connor Brewster <cbrewster@hey.com>
2024-05-06 15:24:17 +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 feat(tvix/store): use async nar reader for ingest_nar 2024-05-06 15:24:17 +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 async nar reader for ingest_nar 2024-05-06 15:24:17 +00:00
default.nix test(tvix/[ca]store): enable bigtable only with "integration" feature 2024-05-03 08:53:09 +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.