Struct Command 

pub struct Command<V> {
    pub from: NodeId,
    pub cid: u64,
    pub value: V,
}

The source’s c = ⟨κ, cid, op⟩: who asked, which request of theirs it is, and what it says.

Both identifying halves are load-bearing. from is what the port’s LogInd::Ordered reports, and the page carries it for the same reason — the reply goes back to κ. cid is what keeps two appends of the same value from collapsing into one: perform skips a command it has already applied, and without cid a client appending 7 twice would see one entry.

cid’s scope is this incarnation. It is a counter in volatile state, exactly as the Synod ballot’s round is, and a restarted process re-mints values it has already used. A request carrying a reused ⟨from, cid⟩ can be taken for one already applied and dropped, which is the identity rule’s worked example: an identifier that crosses the wire outlives the handler that minted it, so its generator is state with a scope, and this one survives nothing. Making it durable is part of the fail-recovery change, not this one.

Fields

from: NodeId

κ — the process that appended it.

cid: u64

cid — which request of that process’s this is. Scope: this incarnation.

value: V

op — what the command says. A value rather than an operation; see the departures.

Trait Implementations

impl<V: Clone> Clone for Command<V>

fn clone(&self) -> Command<V>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<V: Debug> Debug for Command<V>

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

Formats the value using the given formatter.

impl<'de, V> Deserialize<'de> for Command<V>

where V: Deserialize<'de>,

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<V: Eq> Eq for Command<V>

impl<V: Ord> Ord for Command<V>

fn cmp(&self, other: &Command<V>) -> 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<V: PartialEq> PartialEq for Command<V>

fn eq(&self, other: &Command<V>) -> bool

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

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<V: PartialOrd> PartialOrd for Command<V>

fn partial_cmp(&self, other: &Command<V>) -> 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<V> Serialize for Command<V>

where V: Serialize,

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl<V: PartialEq> StructuralPartialEq for Command<V>