pub struct QueueIter { /* private fields */ }
Expand description
An Iterator
that iterates over the elements of the queue, until it hts
the end for the first time. Use this structure instead of
crate::Receiver
if you just need to read the data stored in a queue.
Three good reasons for this are:
- The API is synchronous, since there is no need to wait for new elements.
- There is no transactional mechanism involved, since there is no need for one and, because of this,
- Elements are not buffered in memory, as opposed to what
crate::Receiver::recv_batch
does.
And you also get some extra percents of performance from a simpler implementation. Don’t pay for what you don’t use!
Implementations§
source§impl QueueIter
impl QueueIter
sourcepub fn open<P: AsRef<Path>>(base: P) -> Result<QueueIter>
pub fn open<P: AsRef<Path>>(base: P) -> Result<QueueIter>
Opens a queue for reading. The access will be exclusive, based on the
existence of the temporary file recv.lock
inside the queue folder.
Errors
This function will return an IO error if the queue is already in use for receiving, which is indicated by a lock file. Also, any other IO error encountered while opening will be sent.
Panics
This function will panic if it is not able to set up the notification handler to watch for file changes.
Trait Implementations§
source§impl Iterator for QueueIter
impl Iterator for QueueIter
source§fn next(&mut self) -> Option<Result<Vec<u8>>>
fn next(&mut self) -> Option<Result<Vec<u8>>>
source§fn next_chunk<const N: usize>(
&mut self
) -> Result<[Self::Item; N], IntoIter<Self::Item, N>>where
Self: Sized,
fn next_chunk<const N: usize>( &mut self ) -> Result<[Self::Item; N], IntoIter<Self::Item, N>>where Self: Sized,
iter_next_chunk
)N
values. Read more1.0.0 · source§fn size_hint(&self) -> (usize, Option<usize>)
fn size_hint(&self) -> (usize, Option<usize>)
1.0.0 · source§fn count(self) -> usizewhere
Self: Sized,
fn count(self) -> usizewhere Self: Sized,
1.0.0 · source§fn last(self) -> Option<Self::Item>where
Self: Sized,
fn last(self) -> Option<Self::Item>where Self: Sized,
source§fn advance_by(&mut self, n: usize) -> Result<(), NonZeroUsize>
fn advance_by(&mut self, n: usize) -> Result<(), NonZeroUsize>
iter_advance_by
)n
elements. Read more1.0.0 · source§fn nth(&mut self, n: usize) -> Option<Self::Item>
fn nth(&mut self, n: usize) -> Option<Self::Item>
n
th element of the iterator. Read more1.28.0 · source§fn step_by(self, step: usize) -> StepBy<Self>where
Self: Sized,
fn step_by(self, step: usize) -> StepBy<Self>where Self: Sized,
1.0.0 · source§fn chain<U>(self, other: U) -> Chain<Self, <U as IntoIterator>::IntoIter>where
Self: Sized,
U: IntoIterator<Item = Self::Item>,
fn chain<U>(self, other: U) -> Chain<Self, <U as IntoIterator>::IntoIter>where Self: Sized, U: IntoIterator<Item = Self::Item>,
1.0.0 · source§fn zip<U>(self, other: U) -> Zip<Self, <U as IntoIterator>::IntoIter>where
Self: Sized,
U: IntoIterator,
fn zip<U>(self, other: U) -> Zip<Self, <U as IntoIterator>::IntoIter>where Self: Sized, U: IntoIterator,
source§fn intersperse_with<G>(self, separator: G) -> IntersperseWith<Self, G>where
Self: Sized,
G: FnMut() -> Self::Item,
fn intersperse_with<G>(self, separator: G) -> IntersperseWith<Self, G>where Self: Sized, G: FnMut() -> Self::Item,
iter_intersperse
)separator
between adjacent items of the original iterator. Read more1.0.0 · source§fn map<B, F>(self, f: F) -> Map<Self, F>where
Self: Sized,
F: FnMut(Self::Item) -> B,
fn map<B, F>(self, f: F) -> Map<Self, F>where Self: Sized, F: FnMut(Self::Item) -> B,
1.21.0 · source§fn for_each<F>(self, f: F)where
Self: Sized,
F: FnMut(Self::Item),
fn for_each<F>(self, f: F)where Self: Sized, F: FnMut(Self::Item),
1.0.0 · source§fn filter<P>(self, predicate: P) -> Filter<Self, P>where
Self: Sized,
P: FnMut(&Self::Item) -> bool,
fn filter<P>(self, predicate: P) -> Filter<Self, P>where Self: Sized, P: FnMut(&Self::Item) -> bool,
1.0.0 · source§fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F>where
Self: Sized,
F: FnMut(Self::Item) -> Option<B>,
fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F>where Self: Sized, F: FnMut(Self::Item) -> Option<B>,
1.0.0 · source§fn enumerate(self) -> Enumerate<Self>where
Self: Sized,
fn enumerate(self) -> Enumerate<Self>where Self: Sized,
1.0.0 · source§fn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P>where
Self: Sized,
P: FnMut(&Self::Item) -> bool,
fn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P>where Self: Sized, P: FnMut(&Self::Item) -> bool,
1.0.0 · source§fn take_while<P>(self, predicate: P) -> TakeWhile<Self, P>where
Self: Sized,
P: FnMut(&Self::Item) -> bool,
fn take_while<P>(self, predicate: P) -> TakeWhile<Self, P>where Self: Sized, P: FnMut(&Self::Item) -> bool,
1.57.0 · source§fn map_while<B, P>(self, predicate: P) -> MapWhile<Self, P>where
Self: Sized,
P: FnMut(Self::Item) -> Option<B>,
fn map_while<B, P>(self, predicate: P) -> MapWhile<Self, P>where Self: Sized, P: FnMut(Self::Item) -> Option<B>,
1.0.0 · source§fn skip(self, n: usize) -> Skip<Self>where
Self: Sized,
fn skip(self, n: usize) -> Skip<Self>where Self: Sized,
n
elements. Read more1.0.0 · source§fn take(self, n: usize) -> Take<Self>where
Self: Sized,
fn take(self, n: usize) -> Take<Self>where Self: Sized,
n
elements, or fewer
if the underlying iterator ends sooner. Read more1.0.0 · source§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>,
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>,
1.0.0 · source§fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F>where
Self: Sized,
U: IntoIterator,
F: FnMut(Self::Item) -> U,
fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F>where Self: Sized, U: IntoIterator, F: FnMut(Self::Item) -> U,
1.29.0 · source§fn flatten(self) -> Flatten<Self>where
Self: Sized,
Self::Item: IntoIterator,
fn flatten(self) -> Flatten<Self>where Self: Sized, Self::Item: IntoIterator,
source§fn map_windows<F, R, const N: usize>(self, f: F) -> MapWindows<Self, F, N>where
Self: Sized,
F: FnMut(&[Self::Item; N]) -> R,
fn map_windows<F, R, const N: usize>(self, f: F) -> MapWindows<Self, F, N>where Self: Sized, F: FnMut(&[Self::Item; N]) -> R,
iter_map_windows
)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. Read more1.0.0 · source§fn inspect<F>(self, f: F) -> Inspect<Self, F>where
Self: Sized,
F: FnMut(&Self::Item),
fn inspect<F>(self, f: F) -> Inspect<Self, F>where Self: Sized, F: FnMut(&Self::Item),
1.0.0 · source§fn by_ref(&mut self) -> &mut Selfwhere
Self: Sized,
fn by_ref(&mut self) -> &mut Selfwhere Self: Sized,
1.0.0 · source§fn collect<B>(self) -> Bwhere
B: FromIterator<Self::Item>,
Self: Sized,
fn collect<B>(self) -> Bwhere B: FromIterator<Self::Item>, Self: Sized,
source§fn try_collect<B>(
&mut self
) -> <<Self::Item as Try>::Residual as Residual<B>>::TryTypewhere
Self: Sized,
Self::Item: Try,
<Self::Item as Try>::Residual: Residual<B>,
B: FromIterator<<Self::Item as Try>::Output>,
fn try_collect<B>( &mut self ) -> <<Self::Item as Try>::Residual as Residual<B>>::TryTypewhere Self: Sized, Self::Item: Try, <Self::Item as Try>::Residual: Residual<B>, B: FromIterator<<Self::Item as Try>::Output>,
iterator_try_collect
)source§fn collect_into<E>(self, collection: &mut E) -> &mut Ewhere
E: Extend<Self::Item>,
Self: Sized,
fn collect_into<E>(self, collection: &mut E) -> &mut Ewhere E: Extend<Self::Item>, Self: Sized,
iter_collect_into
)1.0.0 · source§fn partition<B, F>(self, f: F) -> (B, B)where
Self: Sized,
B: Default + Extend<Self::Item>,
F: FnMut(&Self::Item) -> bool,
fn partition<B, F>(self, f: F) -> (B, B)where Self: Sized, B: Default + Extend<Self::Item>, F: FnMut(&Self::Item) -> bool,
source§fn is_partitioned<P>(self, predicate: P) -> boolwhere
Self: Sized,
P: FnMut(Self::Item) -> bool,
fn is_partitioned<P>(self, predicate: P) -> boolwhere Self: Sized, P: FnMut(Self::Item) -> bool,
iter_is_partitioned
)true
precede all those that return false
. Read more1.27.0 · source§fn try_fold<B, F, R>(&mut self, init: B, f: F) -> Rwhere
Self: Sized,
F: FnMut(B, Self::Item) -> R,
R: Try<Output = B>,
fn try_fold<B, F, R>(&mut self, init: B, f: F) -> Rwhere Self: Sized, F: FnMut(B, Self::Item) -> R, R: Try<Output = B>,
1.27.0 · source§fn try_for_each<F, R>(&mut self, f: F) -> Rwhere
Self: Sized,
F: FnMut(Self::Item) -> R,
R: Try<Output = ()>,
fn try_for_each<F, R>(&mut self, f: F) -> Rwhere Self: Sized, F: FnMut(Self::Item) -> R, R: Try<Output = ()>,
1.0.0 · source§fn fold<B, F>(self, init: B, f: F) -> Bwhere
Self: Sized,
F: FnMut(B, Self::Item) -> B,
fn fold<B, F>(self, init: B, f: F) -> Bwhere Self: Sized, F: FnMut(B, Self::Item) -> B,
1.51.0 · source§fn reduce<F>(self, f: F) -> Option<Self::Item>where
Self: Sized,
F: FnMut(Self::Item, Self::Item) -> Self::Item,
fn reduce<F>(self, f: F) -> Option<Self::Item>where Self: Sized, F: FnMut(Self::Item, Self::Item) -> Self::Item,
source§fn try_reduce<F, R>(
&mut self,
f: F
) -> <<R as Try>::Residual as Residual<Option<<R as Try>::Output>>>::TryTypewhere
Self: Sized,
F: FnMut(Self::Item, Self::Item) -> R,
R: Try<Output = Self::Item>,
<R as Try>::Residual: Residual<Option<Self::Item>>,
fn try_reduce<F, R>( &mut self, f: F ) -> <<R as Try>::Residual as Residual<Option<<R as Try>::Output>>>::TryTypewhere Self: Sized, F: FnMut(Self::Item, Self::Item) -> R, R: Try<Output = Self::Item>, <R as Try>::Residual: Residual<Option<Self::Item>>,
iterator_try_reduce
)1.0.0 · source§fn all<F>(&mut self, f: F) -> boolwhere
Self: Sized,
F: FnMut(Self::Item) -> bool,
fn all<F>(&mut self, f: F) -> boolwhere Self: Sized, F: FnMut(Self::Item) -> bool,
1.0.0 · source§fn any<F>(&mut self, f: F) -> boolwhere
Self: Sized,
F: FnMut(Self::Item) -> bool,
fn any<F>(&mut self, f: F) -> boolwhere Self: Sized, F: FnMut(Self::Item) -> bool,
1.0.0 · source§fn find<P>(&mut self, predicate: P) -> Option<Self::Item>where
Self: Sized,
P: FnMut(&Self::Item) -> bool,
fn find<P>(&mut self, predicate: P) -> Option<Self::Item>where Self: Sized, P: FnMut(&Self::Item) -> bool,
1.30.0 · source§fn find_map<B, F>(&mut self, f: F) -> Option<B>where
Self: Sized,
F: FnMut(Self::Item) -> Option<B>,
fn find_map<B, F>(&mut self, f: F) -> Option<B>where Self: Sized, F: FnMut(Self::Item) -> Option<B>,
source§fn try_find<F, R>(
&mut self,
f: F
) -> <<R as Try>::Residual as Residual<Option<Self::Item>>>::TryTypewhere
Self: Sized,
F: FnMut(&Self::Item) -> R,
R: Try<Output = bool>,
<R as Try>::Residual: Residual<Option<Self::Item>>,
fn try_find<F, R>( &mut self, f: F ) -> <<R as Try>::Residual as Residual<Option<Self::Item>>>::TryTypewhere Self: Sized, F: FnMut(&Self::Item) -> R, R: Try<Output = bool>, <R as Try>::Residual: Residual<Option<Self::Item>>,
try_find
)1.0.0 · source§fn position<P>(&mut self, predicate: P) -> Option<usize>where
Self: Sized,
P: FnMut(Self::Item) -> bool,
fn position<P>(&mut self, predicate: P) -> Option<usize>where Self: Sized, P: FnMut(Self::Item) -> bool,
1.6.0 · source§fn max_by_key<B, F>(self, f: F) -> Option<Self::Item>where
B: Ord,
Self: Sized,
F: FnMut(&Self::Item) -> B,
fn max_by_key<B, F>(self, f: F) -> Option<Self::Item>where B: Ord, Self: Sized, F: FnMut(&Self::Item) -> B,
1.15.0 · source§fn max_by<F>(self, compare: F) -> Option<Self::Item>where
Self: Sized,
F: FnMut(&Self::Item, &Self::Item) -> Ordering,
fn max_by<F>(self, compare: F) -> Option<Self::Item>where Self: Sized, F: FnMut(&Self::Item, &Self::Item) -> Ordering,
1.6.0 · source§fn min_by_key<B, F>(self, f: F) -> Option<Self::Item>where
B: Ord,
Self: Sized,
F: FnMut(&Self::Item) -> B,
fn min_by_key<B, F>(self, f: F) -> Option<Self::Item>where B: Ord, Self: Sized, F: FnMut(&Self::Item) -> B,
1.15.0 · source§fn min_by<F>(self, compare: F) -> Option<Self::Item>where
Self: Sized,
F: FnMut(&Self::Item, &Self::Item) -> Ordering,
fn min_by<F>(self, compare: F) -> Option<Self::Item>where Self: Sized, F: FnMut(&Self::Item, &Self::Item) -> Ordering,
1.0.0 · source§fn unzip<A, B, FromA, FromB>(self) -> (FromA, FromB)where
FromA: Default + Extend<A>,
FromB: Default + Extend<B>,
Self: Sized + Iterator<Item = (A, B)>,
fn unzip<A, B, FromA, FromB>(self) -> (FromA, FromB)where FromA: Default + Extend<A>, FromB: Default + Extend<B>, Self: Sized + Iterator<Item = (A, B)>,
1.36.0 · source§fn copied<'a, T>(self) -> Copied<Self>where
T: 'a + Copy,
Self: Sized + Iterator<Item = &'a T>,
fn copied<'a, T>(self) -> Copied<Self>where T: 'a + Copy, Self: Sized + Iterator<Item = &'a T>,
1.0.0 · source§fn cloned<'a, T>(self) -> Cloned<Self>where
T: 'a + Clone,
Self: Sized + Iterator<Item = &'a T>,
fn cloned<'a, T>(self) -> Cloned<Self>where T: 'a + Clone, Self: Sized + Iterator<Item = &'a T>,
source§fn array_chunks<const N: usize>(self) -> ArrayChunks<Self, N>where
Self: Sized,
fn array_chunks<const N: usize>(self) -> ArrayChunks<Self, N>where Self: Sized,
iter_array_chunks
)N
elements of the iterator at a time. Read more1.11.0 · source§fn sum<S>(self) -> Swhere
Self: Sized,
S: Sum<Self::Item>,
fn sum<S>(self) -> Swhere Self: Sized, S: Sum<Self::Item>,
1.11.0 · source§fn product<P>(self) -> Pwhere
Self: Sized,
P: Product<Self::Item>,
fn product<P>(self) -> Pwhere Self: Sized, P: Product<Self::Item>,
source§fn cmp_by<I, F>(self, other: I, cmp: F) -> Orderingwhere
Self: Sized,
I: IntoIterator,
F: FnMut(Self::Item, <I as IntoIterator>::Item) -> Ordering,
fn cmp_by<I, F>(self, other: I, cmp: F) -> Orderingwhere Self: Sized, I: IntoIterator, F: FnMut(Self::Item, <I as IntoIterator>::Item) -> Ordering,
iter_order_by
)Iterator
with those
of another with respect to the specified comparison function. Read more1.5.0 · source§fn partial_cmp<I>(self, other: I) -> Option<Ordering>where
I: IntoIterator,
Self::Item: PartialOrd<<I as IntoIterator>::Item>,
Self: Sized,
fn partial_cmp<I>(self, other: I) -> Option<Ordering>where I: IntoIterator, Self::Item: PartialOrd<<I as IntoIterator>::Item>, Self: Sized,
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. Read moresource§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>,
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>,
iter_order_by
)Iterator
with those
of another with respect to the specified comparison function. Read more1.5.0 · source§fn eq<I>(self, other: I) -> boolwhere
I: IntoIterator,
Self::Item: PartialEq<<I as IntoIterator>::Item>,
Self: Sized,
fn eq<I>(self, other: I) -> boolwhere I: IntoIterator, Self::Item: PartialEq<<I as IntoIterator>::Item>, Self: Sized,
source§fn eq_by<I, F>(self, other: I, eq: F) -> boolwhere
Self: Sized,
I: IntoIterator,
F: FnMut(Self::Item, <I as IntoIterator>::Item) -> bool,
fn eq_by<I, F>(self, other: I, eq: F) -> boolwhere Self: Sized, I: IntoIterator, F: FnMut(Self::Item, <I as IntoIterator>::Item) -> bool,
iter_order_by
)1.5.0 · source§fn ne<I>(self, other: I) -> boolwhere
I: IntoIterator,
Self::Item: PartialEq<<I as IntoIterator>::Item>,
Self: Sized,
fn ne<I>(self, other: I) -> boolwhere I: IntoIterator, Self::Item: PartialEq<<I as IntoIterator>::Item>, Self: Sized,
1.5.0 · source§fn lt<I>(self, other: I) -> boolwhere
I: IntoIterator,
Self::Item: PartialOrd<<I as IntoIterator>::Item>,
Self: Sized,
fn lt<I>(self, other: I) -> boolwhere I: IntoIterator, Self::Item: PartialOrd<<I as IntoIterator>::Item>, Self: Sized,
Iterator
are lexicographically
less than those of another. Read more1.5.0 · source§fn le<I>(self, other: I) -> boolwhere
I: IntoIterator,
Self::Item: PartialOrd<<I as IntoIterator>::Item>,
Self: Sized,
fn le<I>(self, other: I) -> boolwhere I: IntoIterator, Self::Item: PartialOrd<<I as IntoIterator>::Item>, Self: Sized,
Iterator
are lexicographically
less or equal to those of another. Read more1.5.0 · source§fn gt<I>(self, other: I) -> boolwhere
I: IntoIterator,
Self::Item: PartialOrd<<I as IntoIterator>::Item>,
Self: Sized,
fn gt<I>(self, other: I) -> boolwhere I: IntoIterator, Self::Item: PartialOrd<<I as IntoIterator>::Item>, Self: Sized,
Iterator
are lexicographically
greater than those of another. Read more1.5.0 · source§fn ge<I>(self, other: I) -> boolwhere
I: IntoIterator,
Self::Item: PartialOrd<<I as IntoIterator>::Item>,
Self: Sized,
fn ge<I>(self, other: I) -> boolwhere I: IntoIterator, Self::Item: PartialOrd<<I as IntoIterator>::Item>, Self: Sized,
Iterator
are lexicographically
greater than or equal to those of another. Read moresource§fn is_sorted_by<F>(self, compare: F) -> boolwhere
Self: Sized,
F: FnMut(&Self::Item, &Self::Item) -> Option<Ordering>,
fn is_sorted_by<F>(self, compare: F) -> boolwhere Self: Sized, F: FnMut(&Self::Item, &Self::Item) -> Option<Ordering>,
is_sorted
)source§fn is_sorted_by_key<F, K>(self, f: F) -> boolwhere
Self: Sized,
F: FnMut(Self::Item) -> K,
K: PartialOrd,
fn is_sorted_by_key<F, K>(self, f: F) -> boolwhere Self: Sized, F: FnMut(Self::Item) -> K, K: PartialOrd,
is_sorted
)