Enum WriteConditionKind 

#[repr(i32)]
pub enum WriteConditionKind {
    WriteConditionNone = 0,
    WriteConditionIfAbsent = 1,
    WriteConditionIfPresent = 2,
    WriteConditionIfValueEquals = 3,
    WriteConditionIfReadSetUnchanged = 4,
    WriteConditionIfSeqEquals = 5,
}

Predicate for a conditional batch gate. Values are deliberately prefixed because proto enum variants share package-level generated names in some languages.

Variants

WriteConditionNone = 0

WriteConditionIfAbsent = 1

WriteConditionIfPresent = 2

WriteConditionIfValueEquals = 3

WriteConditionIfReadSetUnchanged = 4

Multi-key optimistic gate: apply the WHOLE batch only if every entry in read_set still has its observed sequence. Unlike the single-key kinds above, the predicate spans keys the batch does not write, which is what makes snapshot isolation expressible on the generic KV wire instead of only through the agent-specific transaction RPCs.

WriteConditionIfSeqEquals = 5

Single-key CAS on the engine sequence: apply only if the gate key EXISTS and is still at exactly condition_seq.

Not expressible as a one-key read_set. That gate means “not overwritten since” — it rejects only a NEWER version (latest > observed), so an ABSENT key passes it and the write silently CREATES the row. This one means “still exactly this version, and still there”, which is what a fenced compare-and-swap actually promises.

Implementations

impl WriteConditionKind

pub fn is_valid(value: i32) -> bool

Returns true if value is a variant of WriteConditionKind.

pub fn from_i32(value: i32) -> Option<WriteConditionKind>

👎Deprecated:

Use the TryFrom<i32> implementation instead

Converts an i32 to a WriteConditionKind, or None if value is not a valid variant.

impl WriteConditionKind

pub fn as_str_name(&self) -> &'static str

String value of the enum field names used in the ProtoBuf definition.

The values are not transformed in any way and thus are considered stable (if the ProtoBuf definition does not change) and safe for programmatic use.

pub fn from_str_name(value: &str) -> Option<Self>

Creates an enum from field names used in the ProtoBuf definition.

Trait Implementations

impl Clone for WriteConditionKind

fn clone(&self) -> WriteConditionKind

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for WriteConditionKind

impl Debug for WriteConditionKind

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

Formats the value using the given formatter.

impl Default for WriteConditionKind

fn default() -> WriteConditionKind

Returns the “default value” for a type.

impl Eq for WriteConditionKind

impl From<WriteConditionKind> for i32

fn from(value: WriteConditionKind) -> i32

Converts to this type from the input type.

impl Hash for WriteConditionKind

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 WriteConditionKind

fn cmp(&self, other: &WriteConditionKind) -> 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 WriteConditionKind

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for WriteConditionKind

fn partial_cmp(&self, other: &WriteConditionKind) -> 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 StructuralPartialEq for WriteConditionKind

impl TryFrom<i32> for WriteConditionKind

type Error = UnknownEnumValue

The type returned in the event of a conversion error.

fn try_from(value: i32) -> Result<WriteConditionKind, UnknownEnumValue>

Performs the conversion.