Method stable_predicates

nodedb-vector/src/sieve/workload.rs:51–78

Returns `(signature, frequency)` pairs sorted by frequency descending, filtered to those whose frequency exceeds `stable_fraction_threshold`. Frequency is the fraction of total log entries contributed by that predicate. Returns an empty Vec if the log is empty.

(&self)

    /// Frequency is the fraction of total log entries contributed by that
    /// predicate.  Returns an empty Vec if the log is empty.
    pub fn stable_predicates(&self) -> Vec<(PredicateSignature, f32)> {
        if self.log.is_empty() {
            return Vec::new();
        }

        let total = self.log.len() as f32;
        let mut counts: HashMap<&str, usize> = HashMap::new();
        for record in &self.log {
            *counts
                .entry(record.predicate_signature.as_str())
                .or_insert(0) += 1;
        }

        let mut result: Vec<(PredicateSignature, f32)> = counts
            .into_iter()
            .filter_map(|(sig, count)| {
                let freq = count as f32 / total;
                if freq >= self.stable_fraction_threshold {
                    Some((sig.to_owned(), freq))
                } else {
                    None
                }
            })
            .collect();

        result.sort_by(|a, b| b.1.partial_cmp(&a.1).unwrap_or(std::cmp::Ordering::Equal));
        result
    }

    /// Rough 3D cost model for a candidate subindex.
    ///