Struct CountEvaluator 

pub struct CountEvaluator {
    pub(crate) counts: Arc<Counts>,
    pub(crate) statements: RwLock<Vec<Statement>>,
}

The engine: the counts it judges against, and every statement compiled into it.

Fields

counts: Arc<Counts>

statements: RwLock<Vec<Statement>>

Implementations

impl CountEvaluator

pub fn new() -> Self

An engine counting into this process’s counts().

pub fn over(counts: Arc<Counts>) -> Self

An engine counting into counts instead, for a caller that holds its own.

pub(crate) fn statement( &self, compiled: CompiledId, ) -> Result<Statement, EvalError>

pub(crate) fn counted<'a>( statement: &Statement, subject: &'a Subject<'a>, ) -> Option<Option<&'a str>>

The account this write counts against for statement, or None when the statement does not count it: another collection, or a record that names nobody else when the statement asks for one that does.

Trait Implementations

impl Default for CountEvaluator

fn default() -> Self

Returns the “default value” for a type.

impl Evaluator for CountEvaluator

fn observe(&self, event: &Observed<'_>)

Every attempt on the declared surface, admitted or refused, for a statement counting each account. A statement counting the deployment counts only the attempts the policy set allowed.

fn lifecycle(&self, event: &Lifecycle<'_>)

A deleted account’s counts go with it. A freeze does not reset a count and an unfreeze does not hand back a spent hour: this engine refuses and never freezes, so there is no freeze here to re-trip.

fn staleness(&self) -> Staleness

The count is exact and in memory, and every write on the server is routed to a statement counting every collection, so this engine blocks rather than answer from a stale view.

fn compile(&self, predicate: &Value) -> CompileOutcome

Compile a predicate document into a live artifact this evaluator can judge, or say why it cannot.

fn evaluate( &self, subject: &Subject<'_>, compiled: CompiledId, ) -> Result<Outcome, EvalError>

Given a subject and a compiled artifact, return an outcome, from only what subject carries — see this trait’s “What a stateless predicate may reference” for the boundary the signature enforces. compiled names the artifact compile returned for this policy, never [PolicyId] — an evaluator serving many compiled policies tells them apart by compiled alone; it never learns PolicyId, which belongs to the caller’s own tree.

fn policy_lifecycle(&self, event: PolicyLifecycle)

loaded / superseded / removed, so per-policy state does not outlive the artifact it belongs to — see [PolicyLifecycle]’s doc comment. Defaulted to a no-op: an evaluator that holds no state per compiled artifact (this crate’s regex evaluator, most builtins) has nothing to clean up, and should not be forced to write an empty override just to say so.