Struct CountingWriter 

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

Writer wrapper that counts successfully written bytes.

The count is increased only after the wrapped writer reports a successful byte count. Failed writes do not change the counter.

Examples

use std::io::Write;

use qubit_io::CountingWriter;

let mut writer = CountingWriter::new(Vec::new());
writer.write_all(b"abc")?;

assert_eq!(3, writer.bytes_written());
assert_eq!(b"abc", writer.get_ref().as_slice());

Implementations

impl<W> CountingWriter<W>

pub fn new(inner: W) -> Self

Creates a counting writer.

Parameters

• inner: Writer to wrap.

Returns

A new counting writer with a zero byte count.

pub fn bytes_written(&self) -> u64

Returns the number of bytes successfully written through this wrapper.

Returns

Total byte count. The value saturates at u64::MAX.

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> Seek for CountingWriter<W>

where W: Seek,

fn seek(&mut self, position: SeekFrom) -> Result<u64>

Seek to an offset, in bytes, in a stream.

fn rewind(&mut self) -> Result<(), Error>

Rewind to the beginning of a stream.

fn stream_len(&mut self) -> Result<u64, Error>

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

Returns the length of this stream (in bytes).

fn stream_position(&mut self) -> Result<u64, Error>

Returns the current seek position from the start of the stream.

fn seek_relative(&mut self, offset: i64) -> Result<(), Error>

Seeks relative to the current position.

impl<W> Write for CountingWriter<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.