Struct tokio_util::time::DelayQueue
source · [−]pub struct DelayQueue<T> { /* private fields */ }
time
only.Expand description
A queue of delayed elements.
Once an element is inserted into the DelayQueue
, it is yielded once the
specified deadline has been reached.
Usage
Elements are inserted into DelayQueue
using the insert
or
insert_at
methods. A deadline is provided with the item and a Key
is
returned. The key is used to remove the entry or to change the deadline at
which it should be yielded back.
Once delays have been configured, the DelayQueue
is used via its
Stream
implementation. poll_expired
is called. If an entry has reached its
deadline, it is returned. If not, Poll::Pending
is returned indicating that the
current task will be notified once the deadline has been reached.
Stream
implementation
Items are retrieved from the queue via DelayQueue::poll_expired
. If no delays have
expired, no items are returned. In this case, Poll::Pending
is returned and the
current task is registered to be notified once the next item’s delay has
expired.
If no items are in the queue, i.e. is_empty()
returns true
, then poll
returns Poll::Ready(None)
. This indicates that the stream has reached an end.
However, if a new item is inserted after, poll
will once again start
returning items or Poll::Pending
.
Items are returned ordered by their expirations. Items that are configured to expire first will be returned first. There are no ordering guarantees for items configured to expire at the same instant. Also note that delays are rounded to the closest millisecond.
Implementation
The DelayQueue
is backed by a separate instance of a timer wheel similar to that used internally
by Tokio’s standalone timer utilities such as sleep
. Because of this, it offers the same
performance and scalability benefits.
State associated with each entry is stored in a slab
. This amortizes the cost of allocation,
and allows reuse of the memory allocated for expired entires.
Capacity can be checked using capacity
and allocated preemptively by using
the reserve
method.
Usage
Using DelayQueue
to manage cache entries.
use tokio_util::time::{DelayQueue, delay_queue};
use futures::ready;
use std::collections::HashMap;
use std::task::{Context, Poll};
use std::time::Duration;
struct Cache {
entries: HashMap<CacheKey, (Value, delay_queue::Key)>,
expirations: DelayQueue<CacheKey>,
}
const TTL_SECS: u64 = 30;
impl Cache {
fn insert(&mut self, key: CacheKey, value: Value) {
let delay = self.expirations
.insert(key.clone(), Duration::from_secs(TTL_SECS));
self.entries.insert(key, (value, delay));
}
fn get(&self, key: &CacheKey) -> Option<&Value> {
self.entries.get(key)
.map(|&(ref v, _)| v)
}
fn remove(&mut self, key: &CacheKey) {
if let Some((_, cache_key)) = self.entries.remove(key) {
self.expirations.remove(&cache_key);
}
}
fn poll_purge(&mut self, cx: &mut Context<'_>) -> Poll<()> {
while let Some(entry) = ready!(self.expirations.poll_expired(cx)) {
self.entries.remove(entry.get_ref());
}
Poll::Ready(())
}
}
Implementations
sourceimpl<T> DelayQueue<T>
impl<T> DelayQueue<T>
sourcepub fn new() -> DelayQueue<T>
pub fn new() -> DelayQueue<T>
Creates a new, empty, DelayQueue
.
The queue will not allocate storage until items are inserted into it.
Examples
let delay_queue: DelayQueue<u32> = DelayQueue::new();
sourcepub fn with_capacity(capacity: usize) -> DelayQueue<T>
pub fn with_capacity(capacity: usize) -> DelayQueue<T>
Creates a new, empty, DelayQueue
with the specified capacity.
The queue will be able to hold at least capacity
elements without
reallocating. If capacity
is 0, the queue will not allocate for
storage.
Examples
let mut delay_queue = DelayQueue::with_capacity(10);
// These insertions are done without further allocation
for i in 0..10 {
delay_queue.insert(i, Duration::from_secs(i));
}
// This will make the queue allocate additional storage
delay_queue.insert(11, Duration::from_secs(11));
sourcepub fn insert_at(&mut self, value: T, when: Instant) -> Key
pub fn insert_at(&mut self, value: T, when: Instant) -> Key
Inserts value
into the queue set to expire at a specific instant in
time.
This function is identical to insert
, but takes an Instant
instead
of a Duration
.
value
is stored in the queue until when
is reached. At which point,
value
will be returned from poll_expired
. If when
has already been
reached, then value
is immediately made available to poll.
The return value represents the insertion and is used as an argument to
remove
and reset
. Note that Key
is a token and is reused once
value
is removed from the queue either by calling poll_expired
after
when
is reached or by calling remove
. At this point, the caller
must take care to not use the returned Key
again as it may reference
a different item in the queue.
See type level documentation for more details.
Panics
This function panics if when
is too far in the future.
Examples
Basic usage
use tokio::time::{Duration, Instant};
use tokio_util::time::DelayQueue;
let mut delay_queue = DelayQueue::new();
let key = delay_queue.insert_at(
"foo", Instant::now() + Duration::from_secs(5));
// Remove the entry
let item = delay_queue.remove(&key);
assert_eq!(*item.get_ref(), "foo");
sourcepub fn poll_expired(&mut self, cx: &mut Context<'_>) -> Poll<Option<Expired<T>>>
pub fn poll_expired(&mut self, cx: &mut Context<'_>) -> Poll<Option<Expired<T>>>
Attempts to pull out the next value of the delay queue, registering the
current task for wakeup if the value is not yet available, and returning
None
if the queue is exhausted.
sourcepub fn insert(&mut self, value: T, timeout: Duration) -> Key
pub fn insert(&mut self, value: T, timeout: Duration) -> Key
Inserts value
into the queue set to expire after the requested duration
elapses.
This function is identical to insert_at
, but takes a Duration
instead of an Instant
.
value
is stored in the queue until timeout
duration has
elapsed after insert
was called. At that point, value
will
be returned from poll_expired
. If timeout
is a Duration
of
zero, then value
is immediately made available to poll.
The return value represents the insertion and is used as an
argument to remove
and reset
. Note that Key
is a
token and is reused once value
is removed from the queue
either by calling poll_expired
after timeout
has elapsed
or by calling remove
. At this point, the caller must not
use the returned Key
again as it may reference a different
item in the queue.
See type level documentation for more details.
Panics
This function panics if timeout
is greater than the maximum
duration supported by the timer in the current Runtime
.
Examples
Basic usage
use tokio_util::time::DelayQueue;
use std::time::Duration;
let mut delay_queue = DelayQueue::new();
let key = delay_queue.insert("foo", Duration::from_secs(5));
// Remove the entry
let item = delay_queue.remove(&key);
assert_eq!(*item.get_ref(), "foo");
sourcepub fn remove(&mut self, key: &Key) -> Expired<T>
pub fn remove(&mut self, key: &Key) -> Expired<T>
Removes the item associated with key
from the queue.
There must be an item associated with key
. The function returns the
removed item as well as the Instant
at which it will the delay will
have expired.
Panics
The function panics if key
is not contained by the queue.
Examples
Basic usage
use tokio_util::time::DelayQueue;
use std::time::Duration;
let mut delay_queue = DelayQueue::new();
let key = delay_queue.insert("foo", Duration::from_secs(5));
// Remove the entry
let item = delay_queue.remove(&key);
assert_eq!(*item.get_ref(), "foo");
sourcepub fn reset_at(&mut self, key: &Key, when: Instant)
pub fn reset_at(&mut self, key: &Key, when: Instant)
Sets the delay of the item associated with key
to expire at when
.
This function is identical to reset
but takes an Instant
instead of
a Duration
.
The item remains in the queue but the delay is set to expire at when
.
If when
is in the past, then the item is immediately made available to
the caller.
Panics
This function panics if when
is too far in the future or if key
is
not contained by the queue.
Examples
Basic usage
use tokio::time::{Duration, Instant};
use tokio_util::time::DelayQueue;
let mut delay_queue = DelayQueue::new();
let key = delay_queue.insert("foo", Duration::from_secs(5));
// "foo" is scheduled to be returned in 5 seconds
delay_queue.reset_at(&key, Instant::now() + Duration::from_secs(10));
// "foo" is now scheduled to be returned in 10 seconds
sourcepub fn shrink_to_fit(&mut self)
pub fn shrink_to_fit(&mut self)
Shrink the capacity of the slab, which DelayQueue
uses internally for storage allocation.
This function is not guaranteed to, and in most cases, won’t decrease the capacity of the slab
to the number of elements still contained in it, because elements cannot be moved to a different
index. To decrease the capacity to the size of the slab use compact
.
This function can take O(n) time even when the capacity cannot be reduced or the allocation is shrunk in place. Repeated calls run in O(1) though.
sourcepub fn compact(&mut self)
pub fn compact(&mut self)
Shrink the capacity of the slab, which DelayQueue
uses internally for storage allocation,
to the number of elements that are contained in it.
This methods runs in O(n).
Examples
Basic usage
use tokio_util::time::DelayQueue;
use std::time::Duration;
let mut delay_queue = DelayQueue::with_capacity(10);
let key1 = delay_queue.insert(5, Duration::from_secs(5));
let key2 = delay_queue.insert(10, Duration::from_secs(10));
let key3 = delay_queue.insert(15, Duration::from_secs(15));
delay_queue.remove(&key2);
delay_queue.compact();
assert_eq!(delay_queue.capacity(), 2);
sourcepub fn reset(&mut self, key: &Key, timeout: Duration)
pub fn reset(&mut self, key: &Key, timeout: Duration)
Sets the delay of the item associated with key
to expire after
timeout
.
This function is identical to reset_at
but takes a Duration
instead
of an Instant
.
The item remains in the queue but the delay is set to expire after
timeout
. If timeout
is zero, then the item is immediately made
available to the caller.
Panics
This function panics if timeout
is greater than the maximum supported
duration or if key
is not contained by the queue.
Examples
Basic usage
use tokio_util::time::DelayQueue;
use std::time::Duration;
let mut delay_queue = DelayQueue::new();
let key = delay_queue.insert("foo", Duration::from_secs(5));
// "foo" is scheduled to be returned in 5 seconds
delay_queue.reset(&key, Duration::from_secs(10));
// "foo"is now scheduled to be returned in 10 seconds
sourcepub fn clear(&mut self)
pub fn clear(&mut self)
Clears the queue, removing all items.
After calling clear
, poll_expired
will return Ok(Ready(None))
.
Note that this method has no effect on the allocated capacity.
Examples
use tokio_util::time::DelayQueue;
use std::time::Duration;
let mut delay_queue = DelayQueue::new();
delay_queue.insert("foo", Duration::from_secs(5));
assert!(!delay_queue.is_empty());
delay_queue.clear();
assert!(delay_queue.is_empty());
sourcepub fn capacity(&self) -> usize
pub fn capacity(&self) -> usize
Returns the number of elements the queue can hold without reallocating.
Examples
use tokio_util::time::DelayQueue;
let delay_queue: DelayQueue<i32> = DelayQueue::with_capacity(10);
assert_eq!(delay_queue.capacity(), 10);
sourcepub fn len(&self) -> usize
pub fn len(&self) -> usize
Returns the number of elements currently in the queue.
Examples
use tokio_util::time::DelayQueue;
use std::time::Duration;
let mut delay_queue: DelayQueue<i32> = DelayQueue::with_capacity(10);
assert_eq!(delay_queue.len(), 0);
delay_queue.insert(3, Duration::from_secs(5));
assert_eq!(delay_queue.len(), 1);
sourcepub fn reserve(&mut self, additional: usize)
pub fn reserve(&mut self, additional: usize)
Reserves capacity for at least additional
more items to be queued
without allocating.
reserve
does nothing if the queue already has sufficient capacity for
additional
more values. If more capacity is required, a new segment of
memory will be allocated and all existing values will be copied into it.
As such, if the queue is already very large, a call to reserve
can end
up being expensive.
The queue may reserve more than additional
extra space in order to
avoid frequent reallocations.
Panics
Panics if the new capacity exceeds the maximum number of entries the queue can contain.
Examples
use tokio_util::time::DelayQueue;
use std::time::Duration;
let mut delay_queue = DelayQueue::new();
delay_queue.insert("hello", Duration::from_secs(10));
delay_queue.reserve(10);
assert!(delay_queue.capacity() >= 11);
sourcepub fn is_empty(&self) -> bool
pub fn is_empty(&self) -> bool
Returns true
if there are no items in the queue.
Note that this function returns false
even if all items have not yet
expired and a call to poll
will return Poll::Pending
.
Examples
use tokio_util::time::DelayQueue;
use std::time::Duration;
let mut delay_queue = DelayQueue::new();
assert!(delay_queue.is_empty());
delay_queue.insert("hello", Duration::from_secs(5));
assert!(!delay_queue.is_empty());
Trait Implementations
sourceimpl<T: Debug> Debug for DelayQueue<T>
impl<T: Debug> Debug for DelayQueue<T>
sourceimpl<T> Default for DelayQueue<T>
impl<T> Default for DelayQueue<T>
sourcefn default() -> DelayQueue<T>
fn default() -> DelayQueue<T>
Returns the “default value” for a type. Read more
sourceimpl<T> Stream for DelayQueue<T>
impl<T> Stream for DelayQueue<T>
impl<T> Unpin for DelayQueue<T>
Auto Trait Implementations
impl<T> !RefUnwindSafe for DelayQueue<T>
impl<T> Send for DelayQueue<T> where
T: Send,
impl<T> Sync for DelayQueue<T> where
T: Sync,
impl<T> !UnwindSafe for DelayQueue<T>
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
sourceimpl<T> Instrument for T
impl<T> Instrument for T
sourcefn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
sourcefn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
sourceimpl<T> StreamExt for T where
T: Stream + ?Sized,
impl<T> StreamExt for T where
T: Stream + ?Sized,
sourcefn next(&mut self) -> Next<'_, Self> where
Self: Unpin,
fn next(&mut self) -> Next<'_, Self> where
Self: Unpin,
Creates a future that resolves to the next item in the stream. Read more
sourcefn into_future(self) -> StreamFuture<Self> where
Self: Unpin,
fn into_future(self) -> StreamFuture<Self> where
Self: Unpin,
sourcefn map<T, F>(self, f: F) -> Map<Self, F> where
F: FnMut(Self::Item) -> T,
fn map<T, F>(self, f: F) -> Map<Self, F> where
F: FnMut(Self::Item) -> T,
Maps this stream’s items to a different type, returning a new stream of the resulting type. Read more
sourcefn enumerate(self) -> Enumerate<Self>
fn enumerate(self) -> Enumerate<Self>
Creates a stream which gives the current iteration count as well as the next value. Read more
sourcefn filter<Fut, F>(self, f: F) -> Filter<Self, Fut, F> where
F: FnMut(&Self::Item) -> Fut,
Fut: Future<Output = bool>,
fn filter<Fut, F>(self, f: F) -> Filter<Self, Fut, F> where
F: FnMut(&Self::Item) -> Fut,
Fut: Future<Output = bool>,
Filters the values produced by this stream according to the provided asynchronous predicate. Read more
sourcefn filter_map<Fut, T, F>(self, f: F) -> FilterMap<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = Option<T>>,
fn filter_map<Fut, T, F>(self, f: F) -> FilterMap<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = Option<T>>,
Filters the values produced by this stream while simultaneously mapping them to a different type according to the provided asynchronous closure. Read more
sourcefn then<Fut, F>(self, f: F) -> Then<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future,
fn then<Fut, F>(self, f: F) -> Then<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future,
Computes from this stream’s items new items of a different type using an asynchronous closure. Read more
sourcefn collect<C>(self) -> Collect<Self, C> where
C: Default + Extend<Self::Item>,
fn collect<C>(self) -> Collect<Self, C> where
C: Default + Extend<Self::Item>,
Transforms a stream into a collection, returning a future representing the result of that computation. Read more
sourcefn unzip<A, B, FromA, FromB>(self) -> Unzip<Self, FromA, FromB> where
FromA: Default + Extend<A>,
FromB: Default + Extend<B>,
Self: Stream<Item = (A, B)>,
fn unzip<A, B, FromA, FromB>(self) -> Unzip<Self, FromA, FromB> where
FromA: Default + Extend<A>,
FromB: Default + Extend<B>,
Self: Stream<Item = (A, B)>,
Converts a stream of pairs into a future, which resolves to pair of containers. Read more
sourcefn concat(self) -> Concat<Self> where
Self::Item: Extend<<Self::Item as IntoIterator>::Item>,
Self::Item: IntoIterator,
Self::Item: Default,
fn concat(self) -> Concat<Self> where
Self::Item: Extend<<Self::Item as IntoIterator>::Item>,
Self::Item: IntoIterator,
Self::Item: Default,
Concatenate all items of a stream into a single extendable destination, returning a future representing the end result. Read more
sourcefn count(self) -> Count<Self>
fn count(self) -> Count<Self>
Drives the stream to completion, counting the number of items. Read more
sourcefn fold<T, Fut, F>(self, init: T, f: F) -> Fold<Self, Fut, T, F> where
F: FnMut(T, Self::Item) -> Fut,
Fut: Future<Output = T>,
fn fold<T, Fut, F>(self, init: T, f: F) -> Fold<Self, Fut, T, F> where
F: FnMut(T, Self::Item) -> Fut,
Fut: Future<Output = T>,
Execute an accumulating asynchronous computation over a stream, collecting all the values into one final result. Read more
sourcefn any<Fut, F>(self, f: F) -> Any<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = bool>,
fn any<Fut, F>(self, f: F) -> Any<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = bool>,
Execute predicate over asynchronous stream, and return true
if any element in stream satisfied a predicate. Read more
sourcefn all<Fut, F>(self, f: F) -> All<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = bool>,
fn all<Fut, F>(self, f: F) -> All<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = bool>,
Execute predicate over asynchronous stream, and return true
if all element in stream satisfied a predicate. Read more
sourcefn flatten(self) -> Flatten<Self> where
Self::Item: Stream,
fn flatten(self) -> Flatten<Self> where
Self::Item: Stream,
Flattens a stream of streams into just one continuous stream. Read more
sourcefn flatten_unordered(
self,
limit: impl Into<Option<usize>>
) -> FlattenUnordered<Self> where
Self::Item: Stream,
Self::Item: Unpin,
fn flatten_unordered(
self,
limit: impl Into<Option<usize>>
) -> FlattenUnordered<Self> where
Self::Item: Stream,
Self::Item: Unpin,
Flattens a stream of streams into just one continuous stream. Polls inner streams concurrently. Read more
sourcefn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F> where
F: FnMut(Self::Item) -> U,
U: Stream,
fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F> where
F: FnMut(Self::Item) -> U,
U: Stream,
Maps a stream like StreamExt::map
but flattens nested Stream
s. Read more
sourcefn flat_map_unordered<U, F>(
self,
limit: impl Into<Option<usize>>,
f: F
) -> FlatMapUnordered<Self, U, F> where
U: Stream + Unpin,
F: FnMut(Self::Item) -> U,
fn flat_map_unordered<U, F>(
self,
limit: impl Into<Option<usize>>,
f: F
) -> FlatMapUnordered<Self, U, F> where
U: Stream + Unpin,
F: FnMut(Self::Item) -> U,
Maps a stream like StreamExt::map
but flattens nested Stream
s
and polls them concurrently, yielding items in any order, as they made
available. Read more
sourcefn scan<S, B, Fut, F>(self, initial_state: S, f: F) -> Scan<Self, S, Fut, F> where
F: FnMut(&mut S, Self::Item) -> Fut,
Fut: Future<Output = Option<B>>,
fn scan<S, B, Fut, F>(self, initial_state: S, f: F) -> Scan<Self, S, Fut, F> where
F: FnMut(&mut S, Self::Item) -> Fut,
Fut: Future<Output = Option<B>>,
Combinator similar to StreamExt::fold
that holds internal state
and produces a new stream. Read more
sourcefn skip_while<Fut, F>(self, f: F) -> SkipWhile<Self, Fut, F> where
F: FnMut(&Self::Item) -> Fut,
Fut: Future<Output = bool>,
fn skip_while<Fut, F>(self, f: F) -> SkipWhile<Self, Fut, F> where
F: FnMut(&Self::Item) -> Fut,
Fut: Future<Output = bool>,
Skip elements on this stream while the provided asynchronous predicate
resolves to true
. Read more
sourcefn take_while<Fut, F>(self, f: F) -> TakeWhile<Self, Fut, F> where
F: FnMut(&Self::Item) -> Fut,
Fut: Future<Output = bool>,
fn take_while<Fut, F>(self, f: F) -> TakeWhile<Self, Fut, F> where
F: FnMut(&Self::Item) -> Fut,
Fut: Future<Output = bool>,
Take elements from this stream while the provided asynchronous predicate
resolves to true
. Read more
sourcefn take_until<Fut>(self, fut: Fut) -> TakeUntil<Self, Fut> where
Fut: Future,
fn take_until<Fut>(self, fut: Fut) -> TakeUntil<Self, Fut> where
Fut: Future,
Take elements from this stream until the provided future resolves. Read more
sourcefn for_each<Fut, F>(self, f: F) -> ForEach<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = ()>,
fn for_each<Fut, F>(self, f: F) -> ForEach<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = ()>,
Runs this stream to completion, executing the provided asynchronous closure for each element on the stream. Read more
sourcefn for_each_concurrent<Fut, F>(
self,
limit: impl Into<Option<usize>>,
f: F
) -> ForEachConcurrent<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = ()>,
fn for_each_concurrent<Fut, F>(
self,
limit: impl Into<Option<usize>>,
f: F
) -> ForEachConcurrent<Self, Fut, F> where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = ()>,
Runs this stream to completion, executing the provided asynchronous closure for each element on the stream concurrently as elements become available. Read more
sourcefn take(self, n: usize) -> Take<Self>
fn take(self, n: usize) -> Take<Self>
Creates a new stream of at most n
items of the underlying stream. Read more
sourcefn skip(self, n: usize) -> Skip<Self>
fn skip(self, n: usize) -> Skip<Self>
Creates a new stream which skips n
items of the underlying stream. Read more
sourcefn catch_unwind(self) -> CatchUnwind<Self> where
Self: UnwindSafe,
fn catch_unwind(self) -> CatchUnwind<Self> where
Self: UnwindSafe,
Catches unwinding panics while polling the stream. Read more
sourcefn boxed<'a>(
self
) -> Pin<Box<dyn Stream<Item = Self::Item> + Send + 'a, Global>> where
Self: 'a + Send,
fn boxed<'a>(
self
) -> Pin<Box<dyn Stream<Item = Self::Item> + Send + 'a, Global>> where
Self: 'a + Send,
Wrap the stream in a Box, pinning it. Read more
sourcefn boxed_local<'a>(self) -> Pin<Box<dyn Stream<Item = Self::Item> + 'a, Global>> where
Self: 'a,
fn boxed_local<'a>(self) -> Pin<Box<dyn Stream<Item = Self::Item> + 'a, Global>> where
Self: 'a,
Wrap the stream in a Box, pinning it. Read more
sourcefn buffered(self, n: usize) -> Buffered<Self> where
Self::Item: Future,
fn buffered(self, n: usize) -> Buffered<Self> where
Self::Item: Future,
An adaptor for creating a buffered list of pending futures. Read more
sourcefn buffer_unordered(self, n: usize) -> BufferUnordered<Self> where
Self::Item: Future,
fn buffer_unordered(self, n: usize) -> BufferUnordered<Self> where
Self::Item: Future,
An adaptor for creating a buffered list of pending futures (unordered). Read more
sourcefn zip<St>(self, other: St) -> Zip<Self, St> where
St: Stream,
fn zip<St>(self, other: St) -> Zip<Self, St> where
St: Stream,
An adapter for zipping two streams together. Read more
sourcefn chain<St>(self, other: St) -> Chain<Self, St> where
St: Stream<Item = Self::Item>,
fn chain<St>(self, other: St) -> Chain<Self, St> where
St: Stream<Item = Self::Item>,
Adapter for chaining two streams. Read more
sourcefn peekable(self) -> Peekable<Self>
fn peekable(self) -> Peekable<Self>
Creates a new stream which exposes a peek
method. Read more
sourcefn chunks(self, capacity: usize) -> Chunks<Self>
fn chunks(self, capacity: usize) -> Chunks<Self>
An adaptor for chunking up items of the stream inside a vector. Read more
sourcefn ready_chunks(self, capacity: usize) -> ReadyChunks<Self>
fn ready_chunks(self, capacity: usize) -> ReadyChunks<Self>
An adaptor for chunking up ready items of the stream inside a vector. Read more
sourcefn forward<S>(self, sink: S) -> Forward<Self, S> where
S: Sink<Self::Ok, Error = Self::Error>,
Self: TryStream,
fn forward<S>(self, sink: S) -> Forward<Self, S> where
S: Sink<Self::Ok, Error = Self::Error>,
Self: TryStream,
A future that completes after the given stream has been fully processed into the sink and the sink has been flushed and closed. Read more
sourcefn split<Item>(self) -> (SplitSink<Self, Item>, SplitStream<Self>) where
Self: Sink<Item>,
fn split<Item>(self) -> (SplitSink<Self, Item>, SplitStream<Self>) where
Self: Sink<Item>,
Splits this Stream + Sink
object into separate Sink
and Stream
objects. Read more
sourcefn inspect<F>(self, f: F) -> Inspect<Self, F> where
F: FnMut(&Self::Item),
fn inspect<F>(self, f: F) -> Inspect<Self, F> where
F: FnMut(&Self::Item),
Do something with each item of this stream, afterwards passing it on. Read more
sourcefn left_stream<B>(self) -> Either<Self, B> where
B: Stream<Item = Self::Item>,
fn left_stream<B>(self) -> Either<Self, B> where
B: Stream<Item = Self::Item>,
Wrap this stream in an Either
stream, making it the left-hand variant
of that Either
. Read more
sourcefn right_stream<B>(self) -> Either<B, Self> where
B: Stream<Item = Self::Item>,
fn right_stream<B>(self) -> Either<B, Self> where
B: Stream<Item = Self::Item>,
Wrap this stream in an Either
stream, making it the right-hand variant
of that Either
. Read more
sourcefn poll_next_unpin(&mut self, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> where
Self: Unpin,
fn poll_next_unpin(&mut self, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> where
Self: Unpin,
A convenience method for calling Stream::poll_next
on Unpin
stream types. Read more
sourcefn select_next_some(&mut self) -> SelectNextSome<'_, Self> where
Self: Unpin + FusedStream,
fn select_next_some(&mut self) -> SelectNextSome<'_, Self> where
Self: Unpin + FusedStream,
sourceimpl<T> WithSubscriber for T
impl<T> WithSubscriber for T
sourcefn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self> where
S: Into<Dispatch>,
fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self> where
S: Into<Dispatch>,
Attaches the provided Subscriber
to this type, returning a
WithDispatch
wrapper. Read more
sourcefn with_current_subscriber(self) -> WithDispatch<Self>
fn with_current_subscriber(self) -> WithDispatch<Self>
Attaches the current default Subscriber
to this type, returning a
WithDispatch
wrapper. Read more