Struct ChaosWriter 

pub struct ChaosWriter<W: Write> { /* private fields */ }

Wraps a Write and injects failures per a FailureSchedule.

On PartialWrite failures, the wrapper writes one byte (when the caller asked for at least one) before returning the error, so the caller observes a partial-flush state.

On all other failure modes, the wrapper returns the error without writing any bytes.

Example

use dev_chaos::{io::ChaosWriter, FailureMode, FailureSchedule};
use std::io::Write;

let mut sink: Vec<u8> = Vec::new();
let schedule = FailureSchedule::on_attempts(&[2], FailureMode::IoError);
let mut writer = ChaosWriter::new(&mut sink, schedule);

writer.write_all(b"a").unwrap();        // attempt 1: ok
assert!(writer.write_all(b"b").is_err()); // attempt 2: fails
drop(writer);
assert_eq!(sink, b"a");

Implementations

impl<W: Write> ChaosWriter<W>

pub fn new(inner: W, schedule: FailureSchedule) -> Self

Wrap inner with the given schedule.

pub fn attempt_count(&self) -> usize

Number of write attempts (successful or failed) so far.

pub fn into_inner(self) -> W

Consume the wrapper and return the underlying writer.

impl ChaosWriter<File>

pub fn create(path: impl AsRef<Path>, schedule: FailureSchedule) -> Result<Self>

Create a new file at path and wrap it.

pub fn append(path: impl AsRef<Path>, schedule: FailureSchedule) -> Result<Self>

Open an existing file at path for appending and wrap it.

Trait Implementations

impl<W: Write> Write for ChaosWriter<W>

fn write(&mut self, buf: &[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.