Struct Buffer 

pub struct Buffer { /* private fields */ }

the Buffer contains the underlying memory and data positions

In all cases, 0 ≤ position ≤ end ≤ capacity should be true

Implementations

impl Buffer

pub fn with_capacity(capacity: usize) -> Buffer

allocates a new buffer of maximum size capacity

pub fn from_slice(data: &[u8]) -> Buffer

allocates a new buffer containing the slice data

the buffer starts full, its available data size is exactly data.len()

pub fn grow(&mut self, new_size: usize) -> bool

increases the size of the buffer

this does nothing if the buffer is already large enough

pub fn available_data(&self) -> usize

returns how much data can be read from the buffer

pub fn available_space(&self) -> usize

returns how much free space is available to write to

pub fn capacity(&self) -> usize

returns the underlying vector’s size

pub fn empty(&self) -> bool

returns true if there is no more data to read

pub fn consume(&mut self, count: usize) -> usize

advances the position tracker

if the position gets past the buffer’s half, this will call shift() to move the remaining data to the beginning of the buffer

pub fn consume_noshift(&mut self, count: usize) -> usize

advances the position tracker

This method is similar to consume() but will not move data to the beginning of the buffer

pub fn fill(&mut self, count: usize) -> usize

after having written data to the buffer, use this function to indicate how many bytes were written

if there is not enough available space, this function can call shift() to move the remaining data to the beginning of the buffer

pub fn position(&self) -> usize

Get the current position

Examples

use oval::Buffer;
use std::io::{Read,Write};

let mut output = [0;5];

let mut b = Buffer::with_capacity(10);

let res = b.write(&b"abcdefgh"[..]);

b.read(&mut output);

// Position must be 5
assert_eq!(b.position(), 5);
assert_eq!(b.available_data(), 3);

pub fn reset(&mut self)

moves the position and end trackers to the beginning this function does not modify the data

pub fn data(&self) -> &[u8]

returns a slice with all the available data

pub fn space(&mut self) -> &mut [u8]

returns a mutable slice with all the available space to write to

pub fn shift(&mut self)

moves the data at the beginning of the buffer

if the position was more than 0, it is now 0

Trait Implementations

impl Clone for Buffer

fn clone(&self) -> Buffer

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Buffer

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

Formats the value using the given formatter.

impl PartialEq for Buffer

fn eq(&self, other: &Buffer) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Read for Buffer

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>

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

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” adapter 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 Write for Buffer

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.

impl StructuralPartialEq for Buffer