Struct BoundedWriter 

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

A byte allowance and successful-write counter around a caller-owned sink.

Oversized offered buffers are rejected in full before invoking the sink. Short writes count only accepted bytes. Read limits, encoding, hashing, synchronization, atomic publication and cleanup stay with their owners. A sink’s internal buffering/allocation and partial effects on error are not controlled here. Do not publish partial output after a failed producer.

Use io::sink to count serialized bytes without retaining them, or a hashing dependency’s existing Write implementation to bound its input.

Implementations

impl<W> BoundedWriter<W>

pub const fn new(inner: W, limit: u64) -> Self

Select the sink and the inclusive total accepted-byte allowance.

pub const fn bytes_written(&self) -> u64

Bytes reported as accepted by successful underlying writes.

This is neither a durability receipt nor an assertion of serialization success. Underlying errors may have effects not reported by Write.

pub const fn limit_exceeded(&self) -> bool

Whether any offered buffer has been rejected by this byte allowance.

Retained even when an encoder hides the underlying typed IO error. A limit rejection leaves the sink and counter unchanged; later writes that fit are permitted, without clearing this observation.

pub fn into_inner(self) -> W

Recover the original sink, including any partial output after failure.

Does not flush, synchronize, retry, publish or discard output. Callers must explicitly flush through this wrapper when their sink requires it.

Trait Implementations

impl<W: Write> Write for BoundedWriter<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.