Struct ReservationImpl

pub struct ReservationImpl<T: Borrow<U>, U: ReservationOwner + ?Sized> { /* private fields */ }

A reservation guarantees that when it comes time to actually allocate, it will not fail due to lack of space. Sub-reservations (a.k.a. holds) are possible which effectively allows part of a reservation to be set aside until it’s time to commit. Reservations do offer some thread-safety, but some responsibility is born by the caller: e.g. calling forget and reserve at the same time from different threads is unsafe. Reservations are have an |owner_object_id| which associates it with an object under the root object store that the reservation is accounted against.

Implementations

impl<T: Borrow<U> + Clone + Send + Sync, U: ReservationOwner + ?Sized> ReservationImpl<T, U>

pub fn new(owner: T, owner_object_id: Option<u64>, amount: u64) -> Self

pub fn owner_object_id(&self) -> Option<u64>

pub fn amount(&self) -> u64

Returns the total amount of the reservation, not accounting for anything that might be held.

pub fn add(&self, amount: u64)

Adds more to the reservation.

pub fn forget(&self) -> u64

Returns the entire amount of the reservation. The caller is responsible for maintaining consistency, i.e. updating counters, etc, and there can be no sub-reservations (an assert will fire otherwise).

pub fn forget_some(&self, amount: u64)

Takes some of the reservation. The caller is responsible for maintaining consistency, i.e. updating counters, etc. This will assert that the amount being forgotten does not exceed the available reservation amount; the caller should ensure that this is the case.

pub fn reserve(&self, amount: u64) -> Option<ReservationImpl<&Self, Self>>

Reserves exactly amount if possible.

pub fn commit(&self, amount: u64)

Commits a previously reserved amount from this reservation. The caller is responsible for ensuring the amount was reserved.

pub fn give_back(&self, amount: u64)

Returns some of the reservation.

pub fn move_to<V: Borrow<W> + Clone + Send + Sync, W: ReservationOwner + ?Sized>( &self, other: &ReservationImpl<V, W>, amount: u64, )

Moves amount from this reservation to another reservation.

Trait Implementations

impl<T: Borrow<U>, U: ReservationOwner + ?Sized> Debug for ReservationImpl<T, U>

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

Formats the value using the given formatter.

impl<T: Borrow<U>, U: ReservationOwner + ?Sized> Drop for ReservationImpl<T, U>

fn drop(&mut self)

Executes the destructor for this type.

impl<T: Borrow<U> + Send + Sync, U: ReservationOwner + ?Sized> ReservationOwner for ReservationImpl<T, U>

fn release_reservation(&self, owner_object_id: Option<u64>, amount: u64)

Report that bytes are being released from the reservation back to the the |ReservationOwner| where |owner_object_id| is the owner under the root object store associated with the reservation.