Struct NixHTTPPathInfoService 

pub struct NixHTTPPathInfoService<BS: Clone, DS> {
    instance_name: String,
    base_url: Url,
    http_client: ClientWithMiddleware,
    blob_service: BS,
    directory_service: DS,
    layered_blob_service: Cache<BS, GRPCBlobService<Channel>>,
    layered_directory_service: Cache<DS, GRPCDirectoryService<Channel>>,
    trusted_public_keys: Vec<VerifyingKey>,
    force_download_nar: bool,
}

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 Snix 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

layered_blob_service: Cache<BS, GRPCBlobService<Channel>>

A BlobService Cache with ‘far’ talking to the configured endpoint over gRPC. This is used when validating castore-infused NAR URLs in NARInfos. We rely on Cache to insert into ‘near’.

layered_directory_service: Cache<DS, GRPCDirectoryService<Channel>>

A DirectoryService Cache with ‘far’ talking to the configured endpoint over gRPC. This is used when validating castore-infused NAR URLs in NARInfos. We rely on Cache to insert into ‘near’.

trusted_public_keys: Vec<VerifyingKey>

An optional list of narinfo::VerifyingKey. If the list is not empty, the .narinfo files received need to have correct signature by at least one of these.

force_download_nar: bool

Force the download of NAR files, even if there’s castore-infused NAR URLs.

Implementations

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

where BS: Clone, DS: DirectoryService + Clone,

pub fn try_build( instance_name: String, config: NixHTTPPathInfoServiceConfig, blob_service: BS, directory_service: DS, ) -> Result<Self, Error>

fn derive_narinfo_url(&self, digest: [u8; 20]) -> Result<Url, Error>

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 by the output digest.

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

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

Check if a PathInfo exists. Has a naïve default impl, but store implementations may decide to implement their own.

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.

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.