Enum Upsert 

pub enum Upsert<T> {
    Put(T),
    Keep,
    Delete,
}

A write decision for one key.

Returned by an upsert closure — which sees one key — and by an update_many closure, which decides per key across a batch. Both take the decision under the shard lock and apply exactly one of:

• Put — insert or overwrite the value
• Keep — leave the row unchanged (no write, no hook)
• Delete — remove the row if present; no-op if absent

update_many reports the outcome per key as an Applied.

Variants

Put(T)

Store T at the key (insert or overwrite).

Keep

Do not write; the existing row (or absence) is left as-is.

Delete

Delete the key if it exists; absent keys stay absent.

Trait Implementations

impl<T: Clone> Clone for Upsert<T>

fn clone(&self) -> Upsert<T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for Upsert<T>

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

Formats the value using the given formatter.

impl<T: Eq> Eq for Upsert<T>

impl<T> IntoUpsert<T> for Upsert<T>

type Out = ()

Value returned from the upsert method after the decision is applied.

fn into_parts(self) -> (Upsert<T>, ())

Split into the engine decision and the value handed back to the caller.

impl<T: PartialEq> PartialEq for Upsert<T>

fn eq(&self, other: &Upsert<T>) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl<T: PartialEq> StructuralPartialEq for Upsert<T>