Struct tvix_store::nar::seekable::Reader

pub struct Reader<B: BlobService> {
    segments: Vec<(u64, Data)>,
    position_bytes: u64,
    position_index: usize,
    blob_service: Arc<B>,
    seeking: bool,
    current_blob: TryMaybeDone<BoxFuture<'static, Result<Box<dyn BlobReader>>>>,
}

Fields

segments: Vec<(u64, Data)>

position_bytes: u64

position_index: usize

blob_service: Arc<B>

seeking: bool

current_blob: TryMaybeDone<BoxFuture<'static, Result<Box<dyn BlobReader>>>>

Implementations

impl<B: BlobService + 'static> Reader<B>

pub async fn new( root_node: Node, blob_service: B, directory_service: impl DirectoryService, ) -> Result<Self, RenderError>

Creates a new seekable NAR renderer for the given castore root node.

This function pre-fetches the directory closure using get_recursive() and assembles the NAR structure, except the file contents which are stored as ‘holes’ with references to a blob of a specific BLAKE3 digest and known size. The AsyncRead implementation will then switch between serving the precomputed literal segments, and the appropriate blob for the file contents.

pub fn new_with_directory_closure( root_node: Node, blob_service: B, directory_closure: Option<ValidatedDirectoryGraph>, ) -> Result<Self, RenderError>

Creates a new seekable NAR renderer for the given castore root node. This version of the instantiation does not perform any I/O and as such is not async. However it requires all directories to be passed as a ValidatedDirectoryGraph.

panics if the directory closure is not the closure of the root node

pub fn stream_len(&self) -> u64

Trait Implementations

impl<B: BlobService + 'static> AsyncRead for Reader<B>

fn poll_read( self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &mut ReadBuf<'_>, ) -> Poll<Result<()>>

Attempts to read from the AsyncRead into buf.

impl<B: BlobService + 'static> AsyncSeek for Reader<B>

fn start_seek(self: Pin<&mut Self>, pos: SeekFrom) -> Result<()>

Attempts to seek to an offset, in bytes, in a stream.

fn poll_complete( self: Pin<&mut Self>, cx: &mut Context<'_>, ) -> Poll<Result<u64>>

Waits for a seek operation to complete.