Struct HashingWriter 

pub struct HashingWriter<W> { /* private fields */ }

A bounded caller-owned sink with a raw SHA-256 of successful writes.

Counts and hashes only the bytes reported as accepted by the sink. Short writes, interrupted writes and byte allowances use BoundedWriter’s existing contract; Write::write_all handles retries through this wrapper. Sink errors can have unreported partial effects, which cannot be identified. Encoding, flush/sync, publication and recovery remain caller-owned.

Accept a complete artifact identity only after the producer/serializer succeeds. Recovering parts after failure describes an observed prefix, not a completed or durable artifact. This wrapper never publishes output.

Implementations

impl<W> HashingWriter<W>

pub fn new(writer: W, max_bytes: u64) -> Self

Select the sink and inclusive allowance for accepted bytes.

pub const fn bytes_written(&self) -> u64

Number of bytes reported as accepted by successful writes.

pub const fn limit_exceeded(&self) -> bool

Whether an offered buffer has exceeded the selected allowance.

pub fn into_parts(self) -> (W, ArtifactIdentity)

Recover the sink and identity of the observed accepted bytes.

Does not flush, certify producer success or discard partial output. A failed producer must not use this prefix identity to publish an artifact.

Trait Implementations

impl<W: Write> Write for HashingWriter<W>

fn write(&mut self, buffer: &[u8]) -> Result<usize>

Writes a buffer into this writer, returning how many bytes were written.

fn flush(&mut self) -> Result<()>

Flushes this output stream, ensuring that all intermediately buffered contents reach their destination.

fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize, Error>

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

fn is_write_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Writer has an efficient write_vectored implementation.

fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>

Attempts to write an entire buffer into this writer.

fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>

🔬This is a nightly-only experimental API. (write_all_vectored)

Attempts to write multiple buffers into this writer.

fn write_fmt(&mut self, args: Arguments<'_>) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adapter for this instance of Write.