Struct Receiver 

pub struct Receiver<T> { /* private fields */ }

Receiving side of the channel in sync mode. Receivers can be cloned and produce receivers to operate in both sync and async modes.

Examples

let (_s, receiver) = kanal_plus::bounded::<u64>(0);
let async_receiver=receiver.clone_async();

Implementations

impl<T> Receiver<T>

pub fn recv(&self) -> Result<T, ReceiveError>

Receives data from the channel

pub fn recv_timeout(&self, duration: Duration) -> Result<T, ReceiveErrorTimeout>

Tries receiving from the channel within a duration

pub fn drain_into_blocking( &self, vec: &mut Vec<T>, ) -> Result<usize, ReceiveError>

Drains all available messages from the channel into the provided vector, blocking until at least one message is received.

This function combines the behavior of drain_into with blocking semantics:

• If messages are available, it drains all of them and returns immediately
• If no messages are available, it blocks the current thread until at least one message arrives

Returns the number of messages received.

Examples

let mut buf = Vec::new();
loop {
    match r.drain_into_blocking(&mut buf) {
        Ok(count) => {
            assert!(count > 0);
            // process buf...
            buf.clear();
        }
        Err(_) => break, // channel closed
    }
}

pub fn try_recv(&self) -> Result<Option<T>, ReceiveError>

Tries receiving from the channel without waiting on the waitlist. It returns Ok(Some(T)) in case of successful operation and Ok(None) for a failed one, or error in case that channel is closed. Important note: this function is not lock-free as it acquires a mutex guard of the channel internal for a short time.

Examples

loop {
    if let Some(name)=r.try_recv()?{
        println!("Hello {}!",name);
        break;
    }
}

pub fn try_recv_realtime(&self) -> Result<Option<T>, ReceiveError>

Tries receiving from the channel without waiting on the waitlist or waiting for channel internal lock. It returns Ok(Some(T)) in case of successful operation and Ok(None) for a failed one, or error in case that channel is closed. Do not use this function unless you know exactly what you are doing.

Examples

loop {
    if let Some(name)=r.try_recv_realtime()?{
        println!("Hello {}!",name);
        break;
    }
}

pub fn drain_into(&self, vec: &mut Vec<T>) -> Result<usize, ReceiveError>

Drains all available messages from the channel into the provided vector and returns the number of received messages.

The function is designed to be non-blocking, meaning it only processes messages that are readily available and returns immediately with whatever messages are present. It provides a count of received messages, which could be zero if no messages are available at the time of the call.

When using this function, it’s a good idea to check if the returned count is zero to avoid busy-waiting in a loop. If blocking behavior is desired when the count is zero, you can use the recv() function if count is zero. For efficiency, reusing the same vector across multiple calls can help minimize memory allocations. Between uses, you can clear the vector with vec.clear() to prepare it for the next set of messages.

Examples

let mut buf = Vec::with_capacity(1000);
loop {
    if let Ok(count) = r.drain_into(&mut buf) {
        if count == 0 {
           // count is 0, to avoid busy-wait using recv for
           // the first next message
           if let Ok(v) = r.recv() {
              buf.push(v);
           } else {
             break;
           }
        }
        // use buffer
        buf.iter().for_each(|v| println!("{}",v));
    }else{
        println!("Channel closed");
        break;
    }
    buf.clear();
}

pub fn is_disconnected(&self) -> bool

Returns, whether the send side of the channel, is closed or not.

Examples

let (s, r) = kanal_plus::unbounded::<u64>();
drop(s); // drop sender and disconnect the send side from the channel
assert_eq!(r.is_disconnected(),true);

pub fn is_terminated(&self) -> bool

Returns, whether the channel receive side is terminated, and will not return any result in future recv calls.

Examples

let (s, r) = kanal_plus::unbounded::<u64>();
s.send(1).unwrap();
drop(s); // drop sender and disconnect the send side from the channel
assert_eq!(r.is_disconnected(),true);
// Also channel is closed from send side, it's not terminated as there is data in channel queue
assert_eq!(r.is_terminated(),false);
assert_eq!(r.recv().unwrap(),1);
// Now channel receive side is terminated as there is no sender for channel and queue is empty
assert_eq!(r.is_terminated(),true);

pub fn clone_async(&self) -> AsyncReceiver<T>

Clones receiver as the async version of it

pub fn to_async(self) -> AsyncReceiver<T>

Converts Receiver to AsyncReceiver and returns it.

Examples

  let (s, r) = kanal_plus::bounded(0);
  co(async move {
    let r=r.to_async();
    let name=r.recv().await?;
    println!("Hello {}!",name);
    anyhow::Ok(())
  });
  s.send("World")?;

pub fn as_async(&self) -> &AsyncReceiver<T>

Borrows Receiver as AsyncReceiver and returns it.

Examples

  let (s, r) = kanal_plus::bounded(0);
  co(async move {
    let name=r.as_async().recv().await?;
    println!("Hello {}!",name);
    anyhow::Ok(())
  });
  s.send("World")?;

pub fn is_bounded(&self) -> bool

Returns whether the channel is bounded or not.

Examples

let (s, r) = kanal_plus::bounded::<u64>(0);
assert_eq!(s.is_bounded(),true);
assert_eq!(r.is_bounded(),true);

let (s, r) = kanal_plus::unbounded::<u64>();
assert_eq!(s.is_bounded(),false);
assert_eq!(r.is_bounded(),false);

pub fn len(&self) -> usize

Returns length of the queue.

Examples

let (s, r) = kanal_plus::unbounded::<u64>();
assert_eq!(s.len(),0);
assert_eq!(r.len(),0);
s.send(10);
assert_eq!(s.len(),1);
assert_eq!(r.len(),1);

pub fn is_empty(&self) -> bool

Returns whether the channel queue is empty or not.

Examples

let (s, r) = kanal_plus::unbounded::<u64>();
assert_eq!(s.is_empty(),true);
assert_eq!(r.is_empty(),true);

pub fn is_full(&self) -> bool

Returns whether the channel queue is full or not full channels will block on send and recv calls it always returns true for zero sized channels.

Examples

let (s, r) = kanal_plus::bounded(1);
s.send("Hi!").unwrap();
assert_eq!(s.is_full(),true);
assert_eq!(r.is_full(),true);

pub fn capacity(&self) -> usize

Returns capacity of channel (not the queue) for unbounded channels, it will return usize::MAX.

Examples

let (s, r) = kanal_plus::bounded::<u64>(0);
assert_eq!(s.capacity(),0);
assert_eq!(r.capacity(),0);

let (s, r) = kanal_plus::unbounded::<u64>();
assert_eq!(s.capacity(),usize::MAX);
assert_eq!(r.capacity(),usize::MAX);

pub fn receiver_count(&self) -> usize

Returns count of alive receiver instances of the channel.

Examples

let (s, r) = kanal_plus::unbounded::<u64>();
let receiver_clone=r.clone();
assert_eq!(r.receiver_count(),2);

pub fn sender_count(&self) -> usize

Returns count of alive sender instances of the channel.

Examples

let (s, r) = kanal_plus::unbounded::<u64>();
let sender_clone=s.clone();
assert_eq!(r.sender_count(),2);

pub fn close(&self) -> Result<(), CloseError>

Closes the channel completely on both sides and terminates waiting signals.

Examples

let (s, r) = kanal_plus::unbounded::<u64>();
// closes channel on both sides and has same effect as r.close();
s.close().unwrap();
assert_eq!(r.is_closed(),true);
assert_eq!(s.is_closed(),true);

pub fn is_closed(&self) -> bool

Returns whether the channel is closed on both side of send and receive or not.

Examples

let (s, r) = kanal_plus::unbounded::<u64>();
// closes channel on both sides and has same effect as r.close();
s.close();
assert_eq!(r.is_closed(),true);
assert_eq!(s.is_closed(),true);

Trait Implementations

impl<T> Clone for Receiver<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T> Debug for Receiver<T>

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

Formats the value using the given formatter.

impl<T> Drop for Receiver<T>

fn drop(&mut self)

Executes the destructor for this type.

impl<T> Iterator for Receiver<T>

type Item = T

The type of the elements being iterated over.

fn next(&mut self) -> Option<Self::Item>

Advances the iterator and returns the next value.

fn next_chunk<const N: usize>( &mut self, ) -> Result<[Self::Item; N], IntoIter<Self::Item, N>>

where Self: Sized,

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

Advances the iterator and returns an array containing the next N values.

fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the iterator.

fn count(self) -> usize

where Self: Sized,

Consumes the iterator, counting the number of iterations and returning it.

fn last(self) -> Option<Self::Item>

where Self: Sized,

Consumes the iterator, returning the last element.

fn advance_by(&mut self, n: usize) -> Result<(), NonZero<usize>>

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

Advances the iterator by n elements.

fn nth(&mut self, n: usize) -> Option<Self::Item>

Returns the nth element of the iterator.

fn step_by(self, step: usize) -> StepBy<Self>

where Self: Sized,

Creates an iterator starting at the same point, but stepping by the given amount at each iteration.

fn chain<U>(self, other: U) -> Chain<Self, <U as IntoIterator>::IntoIter>

where Self: Sized, U: IntoIterator<Item = Self::Item>,

Takes two iterators and creates a new iterator over both in sequence.

fn zip<U>(self, other: U) -> Zip<Self, <U as IntoIterator>::IntoIter>

where Self: Sized, U: IntoIterator,

‘Zips up’ two iterators into a single iterator of pairs.

fn intersperse(self, separator: Self::Item) -> Intersperse<Self>

where Self: Sized, Self::Item: Clone,

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

Creates a new iterator which places a copy of separator between adjacent items of the original iterator.

fn intersperse_with<G>(self, separator: G) -> IntersperseWith<Self, G>

where Self: Sized, G: FnMut() -> Self::Item,

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

Creates a new iterator which places an item generated by separator between adjacent items of the original iterator.

fn map<B, F>(self, f: F) -> Map<Self, F>

where Self: Sized, F: FnMut(Self::Item) -> B,

Takes a closure and creates an iterator which calls that closure on each element.

fn for_each<F>(self, f: F)

where Self: Sized, F: FnMut(Self::Item),

Calls a closure on each element of an iterator.

fn filter<P>(self, predicate: P) -> Filter<Self, P>

where Self: Sized, P: FnMut(&Self::Item) -> bool,

Creates an iterator which uses a closure to determine if an element should be yielded.

fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F>

where Self: Sized, F: FnMut(Self::Item) -> Option<B>,

Creates an iterator that both filters and maps.

fn enumerate(self) -> Enumerate<Self>

where Self: Sized,

Creates an iterator which gives the current iteration count as well as the next value.

fn peekable(self) -> Peekable<Self>

where Self: Sized,

Creates an iterator which can use the peek and peek_mut methods to look at the next element of the iterator without consuming it. See their documentation for more information.

fn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P>

where Self: Sized, P: FnMut(&Self::Item) -> bool,

Creates an iterator that skips elements based on a predicate.

fn take_while<P>(self, predicate: P) -> TakeWhile<Self, P>

where Self: Sized, P: FnMut(&Self::Item) -> bool,

Creates an iterator that yields elements based on a predicate.

fn map_while<B, P>(self, predicate: P) -> MapWhile<Self, P>

where Self: Sized, P: FnMut(Self::Item) -> Option<B>,

Creates an iterator that both yields elements based on a predicate and maps.

fn skip(self, n: usize) -> Skip<Self>

where Self: Sized,

Creates an iterator that skips the first n elements.

fn take(self, n: usize) -> Take<Self>

where Self: Sized,

Creates an iterator that yields the first n elements, or fewer if the underlying iterator ends sooner.

fn scan<St, B, F>(self, initial_state: St, f: F) -> Scan<Self, St, F>

where Self: Sized, F: FnMut(&mut St, Self::Item) -> Option<B>,

An iterator adapter which, like fold, holds internal state, but unlike fold, produces a new iterator.

fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F>

where Self: Sized, U: IntoIterator, F: FnMut(Self::Item) -> U,

Creates an iterator that works like map, but flattens nested structure.

fn flatten(self) -> Flatten<Self>

where Self: Sized, Self::Item: IntoIterator,

Creates an iterator that flattens nested structure.

fn map_windows<F, R, const N: usize>(self, f: F) -> MapWindows<Self, F, N>

where Self: Sized, F: FnMut(&[Self::Item; N]) -> R,

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

Calls the given function f for each contiguous window of size N over self and returns an iterator over the outputs of f. Like slice::windows(), the windows during mapping overlap as well.

fn fuse(self) -> Fuse<Self>

where Self: Sized,

Creates an iterator which ends after the first None.

fn inspect<F>(self, f: F) -> Inspect<Self, F>

where Self: Sized, F: FnMut(&Self::Item),

Does something with each element of an iterator, passing the value on.

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

where Self: Sized,

Creates a “by reference” adapter for this instance of Iterator.

fn collect<B>(self) -> B

where B: FromIterator<Self::Item>, Self: Sized,

Transforms an iterator into a collection.

fn try_collect<B>( &mut self, ) -> <<Self::Item as Try>::Residual as Residual<B>>::TryType

where Self: Sized, Self::Item: Try, <Self::Item as Try>::Residual: Residual<B>, B: FromIterator<<Self::Item as Try>::Output>,

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

Fallibly transforms an iterator into a collection, short circuiting if a failure is encountered.

fn collect_into<E>(self, collection: &mut E) -> &mut E

where E: Extend<Self::Item>, Self: Sized,

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

Collects all the items from an iterator into a collection.

fn partition<B, F>(self, f: F) -> (B, B)

where Self: Sized, B: Default + Extend<Self::Item>, F: FnMut(&Self::Item) -> bool,

Consumes an iterator, creating two collections from it.

fn is_partitioned<P>(self, predicate: P) -> bool

where Self: Sized, P: FnMut(Self::Item) -> bool,

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

Checks if the elements of this iterator are partitioned according to the given predicate, such that all those that return true precede all those that return false.

fn try_fold<B, F, R>(&mut self, init: B, f: F) -> R

where Self: Sized, F: FnMut(B, Self::Item) -> R, R: Try<Output = B>,

An iterator method that applies a function as long as it returns successfully, producing a single, final value.

fn try_for_each<F, R>(&mut self, f: F) -> R

where Self: Sized, F: FnMut(Self::Item) -> R, R: Try<Output = ()>,

An iterator method that applies a fallible function to each item in the iterator, stopping at the first error and returning that error.

fn fold<B, F>(self, init: B, f: F) -> B

where Self: Sized, F: FnMut(B, Self::Item) -> B,

Folds every element into an accumulator by applying an operation, returning the final result.

fn reduce<F>(self, f: F) -> Option<Self::Item>

where Self: Sized, F: FnMut(Self::Item, Self::Item) -> Self::Item,

Reduces the elements to a single one, by repeatedly applying a reducing operation.

fn try_reduce<R>( &mut self, f: impl FnMut(Self::Item, Self::Item) -> R, ) -> <<R as Try>::Residual as Residual<Option<<R as Try>::Output>>>::TryType

where Self: Sized, R: Try<Output = Self::Item>, <R as Try>::Residual: Residual<Option<Self::Item>>,

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

Reduces the elements to a single one by repeatedly applying a reducing operation. If the closure returns a failure, the failure is propagated back to the caller immediately.

fn all<F>(&mut self, f: F) -> bool

where Self: Sized, F: FnMut(Self::Item) -> bool,

Tests if every element of the iterator matches a predicate.

fn any<F>(&mut self, f: F) -> bool

where Self: Sized, F: FnMut(Self::Item) -> bool,

Tests if any element of the iterator matches a predicate.

fn find<P>(&mut self, predicate: P) -> Option<Self::Item>

where Self: Sized, P: FnMut(&Self::Item) -> bool,

Searches for an element of an iterator that satisfies a predicate.

fn find_map<B, F>(&mut self, f: F) -> Option<B>

where Self: Sized, F: FnMut(Self::Item) -> Option<B>,

Applies function to the elements of iterator and returns the first non-none result.

fn try_find<R>( &mut self, f: impl FnMut(&Self::Item) -> R, ) -> <<R as Try>::Residual as Residual<Option<Self::Item>>>::TryType

where Self: Sized, R: Try<Output = bool>, <R as Try>::Residual: Residual<Option<Self::Item>>,

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

Applies function to the elements of iterator and returns the first true result or the first error.

fn position<P>(&mut self, predicate: P) -> Option<usize>

where Self: Sized, P: FnMut(Self::Item) -> bool,

Searches for an element in an iterator, returning its index.

fn max(self) -> Option<Self::Item>

where Self: Sized, Self::Item: Ord,

Returns the maximum element of an iterator.

fn min(self) -> Option<Self::Item>

where Self: Sized, Self::Item: Ord,

Returns the minimum element of an iterator.

fn max_by_key<B, F>(self, f: F) -> Option<Self::Item>

where B: Ord, Self: Sized, F: FnMut(&Self::Item) -> B,

Returns the element that gives the maximum value from the specified function.

fn max_by<F>(self, compare: F) -> Option<Self::Item>

where Self: Sized, F: FnMut(&Self::Item, &Self::Item) -> Ordering,

Returns the element that gives the maximum value with respect to the specified comparison function.

fn min_by_key<B, F>(self, f: F) -> Option<Self::Item>

where B: Ord, Self: Sized, F: FnMut(&Self::Item) -> B,

Returns the element that gives the minimum value from the specified function.

fn min_by<F>(self, compare: F) -> Option<Self::Item>

where Self: Sized, F: FnMut(&Self::Item, &Self::Item) -> Ordering,

Returns the element that gives the minimum value with respect to the specified comparison function.

fn unzip<A, B, FromA, FromB>(self) -> (FromA, FromB)

where FromA: Default + Extend<A>, FromB: Default + Extend<B>, Self: Sized + Iterator<Item = (A, B)>,

Converts an iterator of pairs into a pair of containers.

fn copied<'a, T>(self) -> Copied<Self>

where T: Copy + 'a, Self: Sized + Iterator<Item = &'a T>,

Creates an iterator which copies all of its elements.

fn cloned<'a, T>(self) -> Cloned<Self>

where T: Clone + 'a, Self: Sized + Iterator<Item = &'a T>,

Creates an iterator which clones all of its elements.

fn cycle(self) -> Cycle<Self>

where Self: Sized + Clone,

Repeats an iterator endlessly.

fn array_chunks<const N: usize>(self) -> ArrayChunks<Self, N>

where Self: Sized,

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

Returns an iterator over N elements of the iterator at a time.

fn sum<S>(self) -> S

where Self: Sized, S: Sum<Self::Item>,

Sums the elements of an iterator.

fn product<P>(self) -> P

where Self: Sized, P: Product<Self::Item>,

Iterates over the entire iterator, multiplying all the elements

fn cmp<I>(self, other: I) -> Ordering

where I: IntoIterator<Item = Self::Item>, Self::Item: Ord, Self: Sized,

Lexicographically compares the elements of this Iterator with those of another.

fn cmp_by<I, F>(self, other: I, cmp: F) -> Ordering

where Self: Sized, I: IntoIterator, F: FnMut(Self::Item, <I as IntoIterator>::Item) -> Ordering,

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

Lexicographically compares the elements of this Iterator with those of another with respect to the specified comparison function.

fn partial_cmp<I>(self, other: I) -> Option<Ordering>

where I: IntoIterator, Self::Item: PartialOrd<<I as IntoIterator>::Item>, Self: Sized,

Lexicographically compares the PartialOrd elements of this Iterator with those of another. The comparison works like short-circuit evaluation, returning a result without comparing the remaining elements. As soon as an order can be determined, the evaluation stops and a result is returned.

fn partial_cmp_by<I, F>(self, other: I, partial_cmp: F) -> Option<Ordering>

where Self: Sized, I: IntoIterator, F: FnMut(Self::Item, <I as IntoIterator>::Item) -> Option<Ordering>,

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

Lexicographically compares the elements of this Iterator with those of another with respect to the specified comparison function.

fn eq<I>(self, other: I) -> bool

where I: IntoIterator, Self::Item: PartialEq<<I as IntoIterator>::Item>, Self: Sized,

Determines if the elements of this Iterator are equal to those of another.

fn eq_by<I, F>(self, other: I, eq: F) -> bool

where Self: Sized, I: IntoIterator, F: FnMut(Self::Item, <I as IntoIterator>::Item) -> bool,

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

Determines if the elements of this Iterator are equal to those of another with respect to the specified equality function.

fn ne<I>(self, other: I) -> bool

where I: IntoIterator, Self::Item: PartialEq<<I as IntoIterator>::Item>, Self: Sized,

Determines if the elements of this Iterator are not equal to those of another.

fn lt<I>(self, other: I) -> bool

where I: IntoIterator, Self::Item: PartialOrd<<I as IntoIterator>::Item>, Self: Sized,

Determines if the elements of this Iterator are lexicographically less than those of another.

fn le<I>(self, other: I) -> bool

where I: IntoIterator, Self::Item: PartialOrd<<I as IntoIterator>::Item>, Self: Sized,

Determines if the elements of this Iterator are lexicographically less or equal to those of another.

fn gt<I>(self, other: I) -> bool

where I: IntoIterator, Self::Item: PartialOrd<<I as IntoIterator>::Item>, Self: Sized,

Determines if the elements of this Iterator are lexicographically greater than those of another.

fn ge<I>(self, other: I) -> bool

where I: IntoIterator, Self::Item: PartialOrd<<I as IntoIterator>::Item>, Self: Sized,

Determines if the elements of this Iterator are lexicographically greater than or equal to those of another.

fn is_sorted(self) -> bool

where Self: Sized, Self::Item: PartialOrd,

Checks if the elements of this iterator are sorted.

fn is_sorted_by<F>(self, compare: F) -> bool

where Self: Sized, F: FnMut(&Self::Item, &Self::Item) -> bool,

Checks if the elements of this iterator are sorted using the given comparator function.

fn is_sorted_by_key<F, K>(self, f: F) -> bool

where Self: Sized, F: FnMut(Self::Item) -> K, K: PartialOrd,

Checks if the elements of this iterator are sorted using the given key extraction function.