Struct buf_redux::Buffer

pub struct Buffer { /* fields omitted */ }

A deque-like datastructure for managing bytes.

Supports interacting via I/O traits like Read and Write, and direct access.

Methods

impl Buffer

fn new() -> Self

Create a new buffer with a default capacity.

fn with_capacity(cap: usize) -> Self

Create a new buffer with the given capacity.

If the Vec ends up with extra capacity, Buffer will use all of it.

fn buffered(&self) -> usize

Return the number of bytes currently in this buffer.

Equivalent to self.buf().len().

fn headroom(&self) -> usize

Return the number of bytes that can be read into this buffer before it needs to grow or the data in the buffer needs to be moved.

fn capacity(&self) -> usize

Return the total capacity of this buffer.

fn is_empty(&self) -> bool

Returns true if there are no bytes in the buffer, false otherwise.

fn grow(&mut self, additional: usize)

Grow the buffer by additional bytes.

Panics

If self.capacity() + additional overflows.

fn make_room(&mut self)

Make room in the buffer, moving data down to the beginning if necessary.

Does not grow the buffer or delete unread bytes from it.

fn buf(&self) -> &[u8]

Get an immutable slice of the available bytes in this buffer.

Call .consume() to remove bytes from the beginning of this slice.

fn buf_mut(&mut self) -> &mut [u8]

Get a mutable slice representing the available bytes in this buffer.

Call .consume() to remove bytes from the beginning of this slice.

fn read_from<R: Read + ?Sized>(&mut self, rdr: &mut R) -> Result<usize>

Read from rdr, returning the number of bytes read or any errors.

If there is no more room at the head of the buffer, this will return Ok(0).

If <R as TrustRead>::is_trusted(rdr) returns true, this method can avoid zeroing the head of the buffer.

See the TrustRead trait for more information.

Panics

If the returned count from rdr.read() overflows the head cursor of this buffer.

fn copy_from_slice(&mut self, src: &[u8]) -> usize

Copy from src to the head of this buffer. Returns the number of bytes copied.

This will not grow the buffer if src is larger than self.headroom(); instead, it will fill the headroom and return the number of bytes copied. If there is no headroom, this returns 0.

fn write_to<W: Write + ?Sized>(&mut self, wrt: &mut W) -> Result<usize>

Write bytes from this buffer to wrt. Returns the number of bytes written or any errors.

If the buffer is empty, returns Ok(0).

Panics

If the count returned by wrt.write() would overflow the tail cursor if added to it.

fn write_all<W: Write + ?Sized>(&mut self, wrt: &mut W) -> Result<()>

Write all bytes in this buffer, ignoring interrupts. Continues writing until the buffer is empty or an error is returned.

Panics

If self.write_to(wrt) panics.

fn copy_to_slice(&mut self, out: &mut [u8]) -> usize

Copy bytes to out from this buffer, returning the number of bytes written.

fn push_bytes(&mut self, bytes: &[u8])

Push bytes to the end of the buffer, growing it if necessary.

fn consume(&mut self, amt: usize)

Consume amt bytes from the tail of this buffer. No more than self.available() bytes will be consumed.

fn clear(&mut self)

Empty this buffer by resetting the cursors.

fn into_inner(self) -> Vec<u8>

Move the bytes down the beginning of the buffer and take the inner vector, truncated to the number of bytes available.

Trait Implementations

impl Debug for Buffer

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

Formats the value using the given formatter.