Struct LimitWriter 

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

Writer wrapper that accepts at most a fixed number of bytes.

Once the remaining limit reaches zero, writes return Ok(0) without touching the inner writer. Callers using Write::write_all will therefore receive the standard write-zero error when trying to write beyond the limit.

Examples

use std::io::Write;

use qubit_io::LimitWriter;

let mut writer = LimitWriter::new(Vec::new(), 3);

assert_eq!(3, writer.write(b"abcdef")?);
assert_eq!(0, writer.remaining());
assert_eq!(0, writer.write(b"x")?);
assert_eq!(b"abc", writer.get_ref().as_slice());

Implementations

impl<W> LimitWriter<W>

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

Creates a writer that accepts at most limit bytes.

Parameters

• inner: Writer to wrap.
• limit: Maximum number of bytes that may be written through this wrapper.

Returns

A new limited writer.

pub fn remaining(&self) -> u64

Returns the number of bytes still accepted by this wrapper.

Returns

Remaining writable byte count before the wrapper reports zero writes.

pub fn get_ref(&self) -> &W

Returns an immutable reference to the wrapped writer.

Returns

The wrapped writer reference.

pub fn get_mut(&mut self) -> &mut W

Returns a mutable reference to the wrapped writer.

Returns

The wrapped writer reference.

pub fn into_inner(self) -> W

Consumes this wrapper and returns the wrapped writer.

Returns

The wrapped writer.

Trait Implementations

impl<W> Write for LimitWriter<W>

where W: Write,

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.