tvl-depot/tvix/store
Connor Brewster 259d7a3cfa refactor(tvix/castore): generalize store ingestion streams
Previously the store ingestion code was coupled to `walkdir::DirEntry`s
produced by the `walkdir` crate which made it impossible to reuse
ingesting from other sources like tarballs or NARs.

This introduces a `IngestionEntry` which carries enough information for
store ingestion and a future for computing the Blake3 digest of files.
This allows the producer to perform file uploads in a way that makes
sense for the source, ie. the filesystem upload could concurrently
upload multiple files at the same time, while the NAR ingestor will need
to ingest the entire blob before yielding the next blob in the stream.
In the future we can buffer small blobs and upload them concurrently,
but the full blob still needs to be read from the NAR before advancing.

Change-Id: I6d144063e2ba5b05e765bac1f27d41b3c8e7b283
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11462
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2024-04-19 20:37:05 +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 refactor(tvix/castore): generalize store ingestion streams 2024-04-19 20:37:05 +00:00
build.rs fix(tvix): don't emit rerun-if-changed 2024-03-16 09:34:10 +00:00
Cargo.toml chore(tvix/store): remove test-case dependency 2024-04-19 19:22:10 +00:00
default.nix feat(tvix/store): add bigtable pathinfoservice backend 2024-04-09 19:40:14 +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.