Struct ringbuf::Consumer

pub struct Consumer<T> { /* fields omitted */ }

Consumer part of ring buffer.

Implementations

impl<T: Sized> Consumer<T>

pub fn capacity(&self) -> usize

Returns capacity of the ring buffer.

The capacity of the buffer is constant.

pub fn is_empty(&self) -> bool

Checks if the ring buffer is empty.

The result may become irrelevant at any time because of concurring activity of the producer.

pub fn is_full(&self) -> bool

Checks if the ring buffer is full.

The result is relevant until you remove items from the consumer.

pub fn len(&self) -> usize

The length of the data stored in the buffer

Actual length may be equal to or greater than the returned value.

pub fn remaining(&self) -> usize

The remaining space in the buffer.

Actual remaining space may be equal to or less than the returning value.

pub fn access<F: FnOnce(&[T], &[T])>(&self, f: F)

Gives immutable access to the elements contained by the ring buffer without removing them.

The method takes a function f as argument. f takes two slices of ring buffer content (the second one or both of them may be empty). First slice contains older elements.

The slices may not include elements pushed to the buffer by concurring producer after the method call.

pub fn access_mut<F: FnOnce(&mut [T], &mut [T])>(&mut self, f: F)

Gives mutable access to the elements contained by the ring buffer without removing them.

The method takes a function f as argument. f takes two slices of ring buffer content (the second one or both of them may be empty). First slice contains older elements.

The iteration may not include elements pushed to the buffer by concurring producer after the method call.

pub unsafe fn pop_access<F>(&mut self, f: F) -> usize where
    F: FnOnce(&mut [MaybeUninit<T>], &mut [MaybeUninit<T>]) -> usize, 

Allows to read from ring buffer memory directry.

This function is unsafe because it gives access to possibly uninitialized memory

The method takes a function f as argument. f takes two slices of ring buffer content (the second one or both of them may be empty). First slice contains older elements.

f should return number of elements been read. There is no checks for returned number - it remains on the developer’s conscience.

The method always calls f even if ring buffer is empty.

The method returns number returned from f.

Safety

The method gives access to ring buffer underlying memory which may be uninitialized.

It’s up to you to copy or drop appropriate elements if you use this function.

pub unsafe fn pop_copy(&mut self, elems: &mut [MaybeUninit<T>]) -> usize

Copies data from the ring buffer to the slice in byte-to-byte manner.

The elems slice should contain un-initialized data before the method call. After the call the copied part of data in elems should be interpreted as initialized. The remaining part is still un-iniitilized.

Returns the number of items been copied.

Safety

The method copies raw data from the ring buffer.

You should manage copied elements after call, otherwise you may get a memory leak.

pub fn pop(&mut self) -> Option<T>

Removes latest element from the ring buffer and returns it. Returns None if the ring buffer is empty.

pub fn pop_each<F: FnMut(T) -> bool>(
    &mut self,
    f: F,
    count: Option<usize>
) -> usize

Repeatedly calls the closure f passing elements removed from the ring buffer to it.

The closure is called until it returns false or the ring buffer is empty.

The method returns number of elements been removed from the buffer.

pub fn for_each<F: FnMut(&T)>(&self, f: F)

Iterate immutably over the elements contained by the ring buffer without removing them.

The iteration may not include elements pushed to the buffer by concurring producer after the method call.

pub fn for_each_mut<F: FnMut(&mut T)>(&mut self, f: F)

Iterate mutably over the elements contained by the ring buffer without removing them.

The iteration may not include elements pushed to the buffer by concurring producer after the method call.

pub fn discard(&mut self, n: usize) -> usize

Removes n items from the buffer and safely drops them.

Returns the number of deleted items.

pub fn move_to(
    &mut self,
    other: &mut Producer<T>,
    count: Option<usize>
) -> usize

Removes at most count elements from the consumer and appends them to the producer. If count is None then as much as possible elements will be moved. The producer and consumer parts may be of different buffers as well as of the same one.

On success returns count of elements been moved.

impl<T: Sized + Copy> Consumer<T>

pub fn pop_slice(&mut self, elems: &mut [T]) -> usize

Removes first elements from the ring buffer and writes them into a slice. Elements should be Copy.

On success returns count of elements been removed from the ring buffer.

impl Consumer<u8>

pub fn write_into(
    &mut self,
    writer: &mut dyn Write,
    count: Option<usize>
) -> Result<usize>

Removes at most first count bytes from the ring buffer and writes them into a Write instance. If count is None then as much as possible bytes will be written.

Returns Ok(n) if write is succeded. n is number of bytes been written. n == 0 means that either write returned zero or ring buffer is empty.

If write is failed or returned an invalid number then error is returned.

Trait Implementations

impl Read for Consumer<u8>

fn read(&mut self, buffer: &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.

unsafe fn initializer(&self) -> Initializer

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

Determines if this Reader can work with buffers of uninitialized memory.

fn read_to_end(&mut self, buf: &mut Vec<u8, Global>) -> 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 by_ref(&mut self) -> &mut Self

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

fn bytes(self) -> Bytes<Self>

Transforms this Read instance to an Iterator over its bytes.

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

Creates an adaptor which will chain this stream with another.

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

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