Struct tvix_store::pathinfoservice::NixHTTPPathInfoService

pub struct NixHTTPPathInfoService<BS, DS> {
    instance_name: String,
    base_url: Url,
    http_client: ClientWithMiddleware,
    blob_service: BS,
    directory_service: DS,
    public_keys: Option<Vec<VerifyingKey>>,
}

NixHTTPPathInfoService acts as a bridge in between the Nix HTTP Binary cache protocol provided by Nix binary caches such as cache.nixos.org, and the Tvix Store Model. It implements the PathInfoService trait in an interesting way: Every PathInfoService::get fetches the .narinfo and referred NAR file, inserting components into a BlobService and DirectoryService, then returning a PathInfo struct with the root.

Due to this being quite a costly operation, clients are expected to layer this service with store composition, so they’re only ingested once.

The client is expected to be (indirectly) using the same BlobService and DirectoryService, so able to fetch referred Directories and Blobs. PathInfoService::put is not implemented and returns an error if called. TODO: what about reading from nix-cache-info?

Fields

instance_name: String

base_url: Url

http_client: ClientWithMiddleware

blob_service: BS

directory_service: DS

public_keys: Option<Vec<VerifyingKey>>

An optional list of [narinfo::PubKey]. If set, the .narinfo files received need to have correct signature by at least one of these.

Implementations

impl<BS, DS> NixHTTPPathInfoService<BS, DS>

pub fn new( instance_name: String, base_url: Url, blob_service: BS, directory_service: DS, ) -> Self

pub fn set_public_keys(&mut self, public_keys: Vec<VerifyingKey>)

Configures Self to validate NARInfo fingerprints with the public keys passed.

Trait Implementations

impl<BS, DS> PathInfoService for NixHTTPPathInfoService<BS, DS>

where BS: BlobService + Send + Sync + Clone + 'static, DS: DirectoryService + Send + Sync + Clone + 'static,

fn get<'life0, 'async_trait>( &'life0 self, digest: [u8; 20], ) -> Pin<Box<dyn Future<Output = Result<Option<PathInfo>, Error>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Retrieve a PathInfo message by the output digest.

fn put<'life0, 'async_trait>( &'life0 self, _path_info: PathInfo, ) -> Pin<Box<dyn Future<Output = Result<PathInfo, Error>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Store a PathInfo message. Implementations MUST call validate and reject invalid messages.

fn list(&self) -> BoxStream<'static, Result<PathInfo, Error>>

Iterate over all PathInfo objects in the store. Implementations can decide to disallow listing.

fn nar_calculation_service(&self) -> Option<Box<dyn NarCalculationService>>

Returns a (more) suitable NarCalculationService. This can be used to offload NAR calculation to the remote side.