tvl-depot/tvix/store
Florian Klink a40d2dcdcd feat(tvix/store): bump fastcdc, use v2020 version
This switches away from the less canonical "ronomon" version to the
implementation as described in the
[paper](https://ieeexplore.ieee.org/document/9055082) by Wen Xia, et
al., in 2020.

That version uses 64-bit hash values and tends to be faster than both
the ronomon and v2016 versions, and produces the same chunking as the
2016 version.

As per https://docs.rs/fastcdc/latest/fastcdc/#implementations-1, it's
the recommended choice.

The crate also gained support for streaming version of chunkers:
https://docs.rs/fastcdc/latest/fastcdc/#large-data, which might be
useful.

Change-Id: Ieabec3da54eb2b73c045cb54e51f7a216f63641e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8134
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
2023-03-10 10:58:55 +00:00
..
docs docs(tvix/store): add document describing why we don't use git trees 2023-03-05 18:33:54 +00:00
protos docs(store/protos): update comment on blobstore Read and Put 2023-02-07 14:14:35 +00:00
src feat(tvix/store): bump fastcdc, use v2020 version 2023-03-10 10:58:55 +00:00
build.rs refactor(tvix/store): remove needless borrow in build.rs 2023-02-15 18:40:36 +00:00
Cargo.toml feat(tvix/store): bump fastcdc, use v2020 version 2023-03-10 10:58:55 +00:00
default.nix refactor(tvix/store): move protobuf build config one level up 2023-01-06 17:57:06 +00:00
README.md docs(tvix/store): add README, document services and store model 2022-12-26 11:38:52 +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 (handled by //tvix/nar-bridge).

More Information

Check the protos/ subfolder 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 &
$ evans --host localhost --port 8000 -r repl
  ______
 |  ____|
 | |__    __   __   __ _   _ __    ___
 |  __|   \ \ / /  / _. | | '_ \  / __|
 | |____   \ V /  | (_| | | | | | \__ \
 |______|   \_/    \__,_| |_| |_| |___/

 more expressive universal gRPC client


tvix.store.v1@localhost:8000> service BlobService

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

tvix.store.v1.BlobService@localhost:8000> call Get --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.