tvl-depot/tvix/store
Florian Klink 20513e7a52 feat(tvix/store/bin): add progress bar infrastructure
This adds the tracing-indicatif crate, and configures it as a layer in
our tracing_subscriber pipeline to emit progress for every span that's
configured so.

It also moves from using std::io::stderr to write logs to using their
writer, to avoid clobbering output.

Progress bar styles are defined in a lazy_static, moving this into a
general tracing is left for later.

This adds some usage of this to the `imports` and `copy` commands.

The output can still be improved a bit - we should  probably split each
task up into a smaller (instrumented) helper functions, so we can create
a progress bar for each task.

Change-Id: I59a1915aa4e0caa89c911632dec59c4cbeba1b89
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11747
Reviewed-by: flokli <flokli@flokli.de>
Reviewed-by: Simon Hauser <simon.hauser@helsinki-systems.de>
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
2024-06-06 09:43:24 +00:00
..
docs chore(tvix/nar-bridge): move to nar-bridge-go 2024-05-15 21:31:36 +00:00
protos refactor(tvix/*/protos): separate lint target 2023-12-11 22:35:39 +00:00
src feat(tvix/store/bin): add progress bar infrastructure 2024-06-06 09:43:24 +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/bin): add progress bar infrastructure 2024-06-06 09:43:24 +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.