Struct FusionOptions 

pub struct FusionOptions {
    pub hops: usize,
    pub graph_boost: f64,
    pub pool: Option<usize>,
}

Tuning knobs for MemoryService::recall_fused.

Default matches the values validated on the LoCoMo/HotpotQA/TimeQA benchmarks (examples/locomo, examples/multihop, examples/timeqa): graph_boost = 0.15 was the optimum of a sweep (0.30/0.50/0.80 all degraded ranking quality), and hops = 2 is the minimum depth at which a fact wired only through a shared topic (the remember_extracted hub scaffolding: fact → hub is hop 1, hub → sibling fact is hop 2) becomes reachable at all.

Fields

hops: usize

Hops the graph traversal walks from the top vector seed.

graph_boost: f64

Weight added to a graph-reached fact’s normalised vector score.

pool: Option<usize>

Depth of the oversampled vector pool fusion re-ranks. None uses the proven default (k scaled up, floored at 64 — see crate::fusion::pool_size). Widen this to give MemoryService::recall_fused_reranked’s reranker more candidates to work with.

Implementations

impl FusionOptions

pub fn from_knobs( hops: Option<usize>, graph_boost: Option<f64>, pool: Option<usize>, ) -> Self

Build options from optional, untrusted tuning knobs, applying the defaults and clamps every binding must enforce identically: hops clamped to the graph-traversal ceiling (clamp_hops), graph_boost defaulted when absent, and pool clamped to the recall ceiling (clamp_recall_limit) or left at the proven default. The MCP recall_fused tool and the Python recall_fused binding both build their options here — same three knobs, same clamps — so the transports can’t drift on what they accept. A non-finite graph_boost is not filtered here — that guard lives in Self::sanitized, applied by fusion itself so every caller is covered, not just this constructor.

pub fn sanitized(self) -> Self

A copy with any non-finite graph_boost (NaN or ±∞) reset to the default. A non-finite boost poisons fusion catastrophically: the score term graph_boost · weight is NaN for every candidate — even a pool-only one, since NaN · 0.0 == NaN — so crate::fusion::fuse’s total_cmp sort sees all scores as equal, degenerates to a no-op, and then truncates away the graph-reached facts fusion exists to surface (they are appended after the vector pool). The result is silently worse than a plain recall. Applied inside recall_fused so no caller — any binding, or a direct Rust user who filled the struct — can trip it, however the options were built.

Trait Implementations

impl Clone for FusionOptions

fn clone(&self) -> FusionOptions

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for FusionOptions

impl Debug for FusionOptions

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

Formats the value using the given formatter.

impl Default for FusionOptions

fn default() -> Self

Returns the “default value” for a type.