Enum OptAnswer 

pub enum OptAnswer<T> {
    Found(T),
    UncorroboratedFound(T),
    CorroboratedAbsent,
    UncorroboratedAbsent,
}

What the peer tier was able to establish about a thing that may or may not exist.

Option cannot express this, and that is precisely how dig_ecosystem#2456 stayed invisible: None was read as “the chain does not have this” while it meant “one anonymous peer sent an empty list”. The two are different facts and a caller needs to tell them apart, so the peer tier reports which one it has and lets the router decide what to do about it.

Variants

Found(T)

The thing exists, here it is, and an independent peer agreed on what it says about the chain.

A record is checkable against its own fields only as far as its IDENTITY: a coin id is SHA256(parent_coin_info ‖ puzzle_hash ‖ amount) and covers nothing else. created_height and spent_height — the entire reason such a read is made — are copied from what the peer sent, so a positive answer is corroborated exactly like an absence is (dig_ecosystem#2462).

UncorroboratedFound(T)

The thing exists on ONE peer’s word, and no independent peer said the same.

The record is still carried, because it is a real answer and the router may yet find a second voice for it; what it is not is evidence about the chain. A consumer handed this directly MUST NOT record a height from it.

CorroboratedAbsent

Two independent peers, at different addresses, both report it absent.

UncorroboratedAbsent

One peer reports it absent and no second independent peer could say so too.

The peer tier has no basis to call this absence. Whether it can become one depends on sources the peer tier does not own, so it hands the undecided fact up rather than deciding it (see QueryRouter, which may corroborate against coinset).

Trait Implementations

impl<T: Clone> Clone for OptAnswer<T>

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

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for OptAnswer<T>

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

Formats the value using the given formatter.

impl<T: Eq> Eq for OptAnswer<T>

impl<T: PartialEq> PartialEq for OptAnswer<T>

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

Equality operator ==.

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

Inequality operator !=.

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