Struct iowrap::ShortRead

pub struct ShortRead<R: Read, I: Iterator<Item = usize>> { /* private fields */ }

Intentionally return short reads, to test Read code.

The decider iterator gets to decide how short a read should be. A read length of 0 generates an ErrorKind::Interrupted error. When the iterator runs out before the reader, read will always return zero-length reads (EOF).

Currently, no effort is made to make reads longer, if the underlying reader naturally returns short reads.

Examples

Short read:

let mut naughty = iowrap::ShortRead::new(
        io::Cursor::new(b"1234567890"),
        vec![2, 3, 4, 5, 6].into_iter()
);
let mut buf = [0u8; 10];
// A `Cursor` would normally return the whole ten bytes here,
// but we've limited it to two bytes.
assert_eq!(2, naughty.read(&mut buf).unwrap());

Interrupted read:

let mut interrupting = iowrap::ShortRead::new(
        io::Cursor::new(b"123"),
        vec![0, 1, 0].into_iter()
);
let mut buf = [0u8; 10];
assert_eq!(io::ErrorKind::Interrupted,
        interrupting.read(&mut buf).unwrap_err().kind());

Implementations

impl<R: Read, I: Iterator<Item = usize>> ShortRead<R, I>

pub fn new(inner: R, decider: I) -> Self

pub fn into_inner(self) -> R

Trait Implementations

impl<R: Read, I: Iterator<Item = usize>> Read for ShortRead<R, I>

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

Pull some bytes from this source into the specified buffer, returning how many bytes were read.

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

Like read, except that it reads into a slice of buffers.

fn is_read_vectored(&self) -> bool

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

Determines if this Reader has an efficient read_vectored implementation.

fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize, Error>

Read all bytes until EOF in this source, placing them into buf.

fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>

Read all bytes until EOF in this source, appending them to buf.

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

Read the exact number of bytes required to fill buf.

fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> Result<(), Error>

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

Pull some bytes from this source into the specified buffer.

fn read_buf_exact(&mut self, cursor: BorrowedCursor<'_>) -> Result<(), Error>

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

Read the exact number of bytes required to fill cursor.

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

where Self: Sized,

Creates a “by reference” adaptor for this instance of Read.

fn bytes(self) -> Bytes<Self>

where Self: Sized,

Transforms this Read instance to an Iterator over its bytes.

fn chain<R>(self, next: R) -> Chain<Self, R>

where R: Read, Self: Sized,

Creates an adapter which will chain this stream with another.

fn take(self, limit: u64) -> Take<Self>

where Self: Sized,

Creates an adapter which will read at most limit bytes from it.