feat(tvix/store): initial dummy implementation

This replaces the hello world example from tvix-store with an actual
gRPC endpoint, implementing all of BlobService, DirectoryService and
PathInfoService.

All RPC methods currently respond with the unimplemented gRPC status.

Co-Authored-By: Márton Boros <martonboros@gmail.com>
Change-Id: Ieba333cca44dc1e3f2ffbe676ba7a99e672b9bfb
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7664
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI

tvix/store/src/dummy_blob_service.rs

@@ -0,0 +1,34 @@
+use tokio_stream::wrappers::ReceiverStream;
+
+use crate::proto::blob_service_server::BlobService;
+use crate::proto::BlobChunk;
+use crate::proto::BlobMeta;
+use crate::proto::PutBlobResponse;
+use crate::proto::ReadBlobRequest;
+use crate::proto::StatBlobRequest;
+use tonic::{Request, Response, Result, Status, Streaming};
+
+pub struct DummyBlobService {}
+
+#[tonic::async_trait]
+impl BlobService for DummyBlobService {
+    type ReadStream = ReceiverStream<Result<BlobChunk>>;
+
+    async fn stat(&self, _request: Request<StatBlobRequest>) -> Result<Response<BlobMeta>> {
+        Err(Status::unimplemented("not implemented"))
+    }
+
+    async fn read(
+        &self,
+        _request: Request<ReadBlobRequest>,
+    ) -> Result<Response<Self::ReadStream>, Status> {
+        Err(Status::unimplemented("not implemented"))
+    }
+
+    async fn put(
+        &self,
+        _request: Request<Streaming<BlobChunk>>,
+    ) -> Result<Response<PutBlobResponse>> {
+        Err(Status::unimplemented("not implemented"))
+    }
+}

tvix/store/src/dummy_directory_service.rs

@@ -0,0 +1,28 @@
+use tokio_stream::wrappers::ReceiverStream;
+
+use crate::proto::directory_service_server::DirectoryService;
+use crate::proto::Directory;
+use crate::proto::GetDirectoryRequest;
+use crate::proto::PutDirectoryResponse;
+use tonic::{Request, Response, Result, Status, Streaming};
+
+pub struct DummyDirectoryService {}
+
+#[tonic::async_trait]
+impl DirectoryService for DummyDirectoryService {
+    type GetStream = ReceiverStream<Result<Directory>>;
+
+    async fn get(
+        &self,
+        _request: Request<GetDirectoryRequest>,
+    ) -> Result<Response<Self::GetStream>, Status> {
+        Err(Status::unimplemented("not implemented"))
+    }
+
+    async fn put(
+        &self,
+        _request: Request<Streaming<Directory>>,
+    ) -> Result<Response<PutDirectoryResponse>> {
+        Err(Status::unimplemented("not implemented"))
+    }
+}

tvix/store/src/dummy_path_info_service.rs

@@ -0,0 +1,26 @@
+use crate::proto::path_info_service_server::PathInfoService;
+use crate::proto::CalculateNarResponse;
+use crate::proto::GetPathInfoRequest;
+use crate::proto::Node;
+use crate::proto::PathInfo;
+use tonic::{Request, Response, Result, Status};
+
+pub struct DummyPathInfoService {}
+
+#[tonic::async_trait]
+impl PathInfoService for DummyPathInfoService {
+    async fn get(&self, _request: Request<GetPathInfoRequest>) -> Result<Response<PathInfo>> {
+        Err(Status::unimplemented("not implemented"))
+    }
+
+    async fn put(&self, _request: Request<PathInfo>) -> Result<Response<PathInfo>> {
+        Err(Status::unimplemented("not implemented"))
+    }
+
+    async fn calculate_nar(
+        &self,
+        _request: Request<Node>,
+    ) -> Result<Response<CalculateNarResponse>> {
+        Err(Status::unimplemented("not implemented"))
+    }
+}

tvix/store/src/main.rs

@@ -1,3 +1,13 @@
+use crate::proto::blob_service_server::BlobServiceServer;
+use crate::proto::directory_service_server::DirectoryServiceServer;
+use crate::proto::path_info_service_server::PathInfoServiceServer;
+
+use clap::Parser;
+use tonic::{transport::Server, Result};
+
+mod dummy_blob_service;
+mod dummy_directory_service;
+mod dummy_path_info_service;
 mod nixbase32;
 mod nixpath;
 mod proto;
@@ -5,6 +15,34 @@ mod proto;
 #[cfg(test)]
 mod tests;
 
-fn main() {
-    println!("Hello, world!");
+#[derive(Parser)]
+#[command(author, version, about, long_about = None)]
+struct Cli {
+    #[clap(long, short = 'l')]
+    listen_address: Option<String>,
+}
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let cli = Cli::parse();
+    let listen_address = cli
+        .listen_address
+        .unwrap_or("[::]:8000".to_string())
+        .parse()
+        .unwrap();
+
+    let blob_service = dummy_blob_service::DummyBlobService {};
+    let directory_service = dummy_directory_service::DummyDirectoryService {};
+    let path_info_service = dummy_path_info_service::DummyPathInfoService {};
+
+    println!("tvix-store listening on {}", listen_address);
+
+    Server::builder()
+        .add_service(BlobServiceServer::new(blob_service))
+        .add_service(DirectoryServiceServer::new(directory_service))
+        .add_service(PathInfoServiceServer::new(path_info_service))
+        .serve(listen_address)
+        .await?;
+
+    Ok(())
 }