Struct IoSlice

pub struct IoSlice<T>
where
    T: Seek,
{ /* private fields */ }

A slice, subset, or view into some object.

IoSlice impls both std::io::Read and std::io::Write when the source implements them (and only one if the source only implements one).

example usage.

use { std::fs::File, slice::IoSlice };


let source = File::open("/home/annie/data.png")?;
let start  = 10;
let length = 1000;


// create a slice into `home/annie/data.png`, consisting of bytes [10 .. 10 + 1000]
// of that file.
//
// `slice` impls both `std::io::Read` and `std::io::Write` because `source`
// does too.
let slice = IoSlice::new(source, start, length);


// use like any other `std::io::Read` or `std::io::Write`:
//
//     slice.read_to_string(...)?;
//     slice.read_exact(...)?;
//     slice.write_all(...)?;
//
//     writeln!(slice, "hello {}", name)?;
//

Implementations

impl<T> IoSlice<T>

where T: Seek,

pub fn new(source: T, begin: u64, length: u64) -> Result<IoSlice<T>, Error>

create a new slice into a specific subset of source.

pub fn len(&self) -> u64

returns the total length of this io slice.

pub fn pos(&self) -> u64

returns the current position of this slice.

pub fn position(&self) -> u64

returns the current position of this slice.

Trait Implementations

impl<T> Clone for IoSlice<T>

where T: Clone + Seek,

fn clone(&self) -> IoSlice<T>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T> Debug for IoSlice<T>

where T: Seek + Debug,

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T> Read for IoSlice<T>

where T: Read + Seek,

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

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

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

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

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

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

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

Reads 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)

Reads 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.

impl<T> Seek for IoSlice<T>

where T: Seek,

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

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<T> TryClone for IoSlice<T>

where T: TryClone + Seek,

fn try_clone(&self) -> Result<IoSlice<T>, Error>

impl<T> Write for IoSlice<T>

where T: Write + Seek,

fn write(&mut self, buffer: &[u8]) -> Result<usize, Error>

Writes a buffer into this writer, returning how many bytes were written.

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

Attempts to write an entire buffer into this writer.

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

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_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.