Struct StdinWriter 

pub struct StdinWriter<'a>(/* private fields */);

The writer a stdin producer is handed: kopia’s stdin, with the ability to CLOSE it removed.

The runner’s ownership of that pipe IS the safety property. kopia finalizes the snapshot when — and only when — stdin reaches EOF, so whoever can close the pipe decides whether the snapshot commits. A producer that called shutdown() on a bare ChildStdin would hand kopia EOF while the runner still believed it held the commit point, and a subsequent StdinOutcome::Abort would then arrive too late: the kill would land on a kopia that had already written a manifest for a TRUNCATED dump.

No producer in this repository does that. This type means none ever can — which is the difference between a bad state being untaken and being unrepresentable.

[tokio::io::AsyncWrite] is implemented so tokio::io::copy still works (the pipe-to-pipe transfer must stay constant-memory and must never buffer the user’s dump), but poll_shutdown is a deliberate NO-OP: it reports success without touching the pipe, so AsyncWriteExt::shutdown() cannot reach it either.

Trait Implementations

impl AsyncWrite for StdinWriter<'_>

fn poll_shutdown( self: Pin<&mut Self>, _cx: &mut Context<'_>, ) -> Poll<Result<()>>

Deliberately does NOT close the pipe. Closing it is the COMMIT decision, and it belongs to the runner alone — see the type’s own documentation. Reports success so a producer that flushes-and-shuts-down (the idiomatic end of a tokio::io::copy pipeline) is not made to look like a failure.

fn poll_write( self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize>>

Attempt to write bytes from buf into the object.

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

Attempts to flush the object, ensuring that any buffered data reach their destination.

fn poll_write_vectored( self: Pin<&mut Self>, cx: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>

Like poll_write, except that it writes from a slice of buffers.

fn is_write_vectored(&self) -> bool

Determines if this writer has an efficient poll_write_vectored implementation.