785ff80c8b
We rely on being able to make small reads cheaply, so this was already an implicit practical requirement. Requiring it explicitly removes a performance footgun, and makes further optimisations possible. Change-Id: I7f65880a41b1d6b5e6bf2e52dfe47d4c49b34bcd Reviewed-on: https://cl.tvl.fyi/c/depot/+/10088 Tested-by: BuildkiteCI Reviewed-by: flokli <flokli@flokli.de> |
||
|---|---|---|
| .. | ||
| docs | ||
| protos | ||
| src | ||
| build.rs | ||
| Cargo.toml | ||
| default.nix | ||
| 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.