Enum Change

pub enum Change {
    Update {
        log: LogChange,
        expected: PreviousValue,
        new: Target,
    },
    Delete {
        expected: PreviousValue,
        log: RefLog,
    },
}

A description of an edit to perform.

Variants

Update

If previous is not None, the ref must exist and its oid must agree with the previous, and we function like update. Otherwise it functions as create-or-update.

Fields

log: LogChange

The desired change to the reference log.

expected: PreviousValue

The expected value already present in the reference. If a ref was existing previously it will be overwritten at MustExistAndMatch(actual_value) for use after the transaction was committed successfully.

new: Target

The new state of the reference, either for updating an existing one or creating a new one.

Delete

Delete a reference and optionally check if previous is its content.

Fields

expected: PreviousValue

The expected value of the reference, with the MustNotExist variant being invalid.

If a previous ref existed, this value will be filled in automatically as MustExistAndMatch(actual_value) and can be accessed if the transaction was committed successfully.

log: RefLog

How to treat the reference log during deletion.

Implementations

impl Change

pub fn new_value(&self) -> Option<TargetRef<'_>>

Return references to values that are the new value after the change is applied, if this is an update.

pub fn previous_value(&self) -> Option<TargetRef<'_>>

Return references to values that are in common between all variants and denote the previous observed value.

Trait Implementations

impl Clone for Change

fn clone(&self) -> Change

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Change

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

Formats the value using the given formatter.

impl Hash for Change

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for Change

fn cmp(&self, other: &Change) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for Change

fn eq(&self, other: &Change) -> bool

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for Change

fn partial_cmp(&self, other: &Change) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Eq for Change

impl StructuralPartialEq for Change