Struct Vehicle 

pub struct Vehicle<SE, S, T, P, PE>
where
    S: Stream<Item = Result<(Cid, Vec<u8>), SE>>,
    P: Fn(&[u8]) -> Result<T, PE>,
    PE: Error,
{ /* private fields */ }

The core driver between the block stream and MST walker

Implementations

impl<SE, S, T: Clone, P, PE> Vehicle<SE, S, T, P, PE>

where SE: Error + 'static, S: Stream<Item = Result<(Cid, Vec<u8>), SE>> + Unpin, P: Fn(&[u8]) -> Result<T, PE>, PE: Error,

pub async fn init( root: Cid, block_stream: S, process: P, ) -> Result<(Commit, Self), DriveError<PE>>

Set up the stream

This will eagerly consume blocks until the Commit object is found. Usually the it’s the first block, but there is no guarantee.

Parameters

root: CID of the commit object that is the root of the MST

block_stream: Input stream of raw CAR blocks

process: record-transforming callback:

For tasks where records can be quickly processed into a smaller useful representation, you can do that eagerly as blocks come in by passing the processor as a callback here. This can reduce overall memory usage.

pub async fn next_record( &mut self, ) -> Result<Option<(String, T)>, DriveError<PE>>

Manually step through the record outputs

pub fn stream(self) -> impl Stream<Item = Result<(String, T), DriveError<PE>>>

Convert to a futures::stream of record outputs