Struct holochain::prelude::kitsune_p2p::dependencies::kitsune_p2p_types::dependencies::ghost_actor::dependencies::observability::tracing::dispatcher::WeakDispatch
source · pub struct WeakDispatch { /* private fields */ }
Expand description
WeakDispatch
is a version of Dispatch
that holds a non-owning reference
to a Subscriber
.
The Subscriber may be accessed by calling [
WeakDispatch::upgrade], which returns an
Option. If all [
Dispatch] clones that point at the
Subscriber have been dropped, [
WeakDispatch::upgrade] will return
None. Otherwise, it will return
Some(Dispatch)`.
A WeakDispatch
may be created from a Dispatch
by calling the
Dispatch::downgrade
method. The primary use for creating a
WeakDispatch
is to allow a Subscriber` to hold a cyclical reference to
itself without creating a memory leak. See here for details.
This type is analogous to the std::sync::Weak
type, but for a
Dispatch
rather than an Arc
.
Implementations
sourceimpl WeakDispatch
impl WeakDispatch
sourcepub fn upgrade(&self) -> Option<Dispatch>
pub fn upgrade(&self) -> Option<Dispatch>
Attempts to upgrade this WeakDispatch
to a Dispatch
.
Returns None
if the referenced Dispatch
has already been dropped.
Examples
let strong = Dispatch::new(NoSubscriber::default());
let weak = strong.downgrade();
// The strong here keeps it alive, so we can still access the object.
assert!(weak.upgrade().is_some());
drop(strong); // But not any more.
assert!(weak.upgrade().is_none());
Trait Implementations
sourceimpl Clone for WeakDispatch
impl Clone for WeakDispatch
sourcefn clone(&self) -> WeakDispatch
fn clone(&self) -> WeakDispatch
1.0.0 · sourcefn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moreAuto Trait Implementations
impl !RefUnwindSafe for WeakDispatch
impl Send for WeakDispatch
impl Sync for WeakDispatch
impl Unpin for WeakDispatch
impl !UnwindSafe for WeakDispatch
Blanket Implementations
impl<T> Any for Twhere
T: Any + ?Sized,
impl<T> Any for Twhere
T: Any + ?Sized,
fn type_id_compat(&self) -> TypeId
fn type_id_compat(&self) -> TypeId
impl<T> ArchivePointee for T
impl<T> ArchivePointee for T
type ArchivedMetadata = ()
type ArchivedMetadata = ()
fn pointer_metadata(
_: &<T as ArchivePointee>::ArchivedMetadata
) -> <T as Pointee>::Metadata
fn pointer_metadata(
_: &<T as ArchivePointee>::ArchivedMetadata
) -> <T as Pointee>::Metadata
sourceimpl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
impl<F, W, T, D> Deserialize<With<T, W>, D> for Fwhere
W: DeserializeWith<F, T, D>,
D: Fallible + ?Sized,
F: ?Sized,
impl<F, W, T, D> Deserialize<With<T, W>, D> for Fwhere
W: DeserializeWith<F, T, D>,
D: Fallible + ?Sized,
F: ?Sized,
fn deserialize(
&self,
deserializer: &mut D
) -> Result<With<T, W>, <D as Fallible>::Error>
fn deserialize(
&self,
deserializer: &mut D
) -> Result<With<T, W>, <D as Fallible>::Error>
impl<T> FutureExt for T
impl<T> FutureExt for T
fn with_context(self, otel_cx: Context) -> WithContext<Self> ⓘ
fn with_context(self, otel_cx: Context) -> WithContext<Self> ⓘ
fn with_current_context(self) -> WithContext<Self> ⓘ
fn with_current_context(self) -> WithContext<Self> ⓘ
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> 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> ⓘ
impl<T> Pointable for T
impl<T> Pointable for T
impl<SS, SP> SupersetOf<SS> for SPwhere
SS: SubsetOf<SP>,
impl<SS, SP> SupersetOf<SS> for SPwhere
SS: SubsetOf<SP>,
fn to_subset(&self) -> Option<SS>
fn to_subset(&self) -> Option<SS>
self
from the equivalent element of its
superset. Read morefn is_in_subset(&self) -> bool
fn is_in_subset(&self) -> bool
self
is actually part of its subset T
(and can be converted to it).fn to_subset_unchecked(&self) -> SS
fn to_subset_unchecked(&self) -> SS
self.to_subset
but without any property checks. Always succeeds.fn from_subset(element: &SS) -> SP
fn from_subset(element: &SS) -> SP
self
to the equivalent element of its superset.