Struct Config 

#[non_exhaustive]
pub struct Config {

    pub dim: usize,
    pub max_bytes: usize,
    pub max_text: usize,
    pub max_blob: usize,
    pub shards_facts: usize,
    pub shards_entities: usize,
    pub shards_edges: usize,
    pub shards_temporal: usize,
    pub shards_postings: usize,
    pub bm25_k1: f32,
    pub bm25_b: f32,
    pub rrf_k: u32,
    pub w_bm25: f32,
    pub w_vec: f32,
    pub w_graph: f32,
    pub w_time: f32,
    pub w_recency: f32,
    pub half_life_days: u32,
    pub graph_depth: u32,
    pub graph_decay: f32,
    pub similar_cos: f32,
    pub similar_jaccard: f32,
    pub hnsw_m: usize,
    pub hnsw_m0: usize,
    pub hnsw_ef_construction: usize,
    pub hnsw_ef_search: usize,
    pub flat_to_hnsw: usize,
    pub db_uuid: u128,
}

Full engine configuration with the defaults.

Plain data: construct with Config::default, override fields, then let the engine call Config::validate (it is also callable directly — useful for surfacing config errors early in wrappers).

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

dim: usize

Vector dimension; 0 disables the vector layer entirely. Max 4096.

max_bytes: usize

Total ceiling for all byte pools (the wasm32 passport: ≤ 2 GiB).

max_text: usize

Maximum fact text length in bytes.

max_blob: usize

Maximum single blob length in bytes.

shards_facts: usize

Shard count of the facts arena (power of two).

shards_entities: usize

Shard count of the entities arena (power of two).

shards_edges: usize

Shard count of each edge arena (power of two).

shards_temporal: usize

Shard count of the temporal arena (power of two).

shards_postings: usize

Shard count of the postings arena (power of two).

bm25_k1: f32

BM25 k1 (term-frequency saturation).

bm25_b: f32

BM25 b (length normalization), in [0, 1].

rrf_k: u32

The RRF rank constant (score += w / (rrf_k + rank)).

w_bm25: f32

RRF weight of the lexical (BM25) source.

w_vec: f32

RRF weight of the vector source.

w_graph: f32

RRF weight of the graph source.

w_time: f32

RRF weight of the temporal-range source.

w_recency: f32

Strength of the recency boost (0 disables it).

half_life_days: u32

Recency half-life in days.

graph_depth: u32

Graph expansion depth limit.

graph_decay: f32

Per-hop weight decay of graph candidates, in (0, 1].

similar_cos: f32

Cosine threshold for vector-based similar-detection, in [0, 1].

similar_jaccard: f32

Jaccard threshold for lexical similar-detection, in [0, 1].

hnsw_m: usize

HNSW: neighbors per node on upper levels.

hnsw_m0: usize

HNSW: neighbors per node on level 0.

hnsw_ef_construction: usize

HNSW: beam width during construction.

hnsw_ef_search: usize

HNSW: default beam width during search (per-query override exists).

flat_to_hnsw: usize

Vector count at which maintain switches Flat → HNSW.

db_uuid: u128

Database lineage identity. Minted once by the host at creation (the no_std core has no RNG) and persisted in every snapshot; it survives maintain and re-saves, so external holders of ids can tell “same database” from “a different one”. 0 means an unnamed (ephemeral/test) database. On open, 0 here adopts whatever the snapshot stores; a nonzero value must match the stored one or the open fails with ConfigMismatch.

Implementations

impl Config

pub fn validate(&self) -> Result<(), Error>

Checks every field against its documented range.

Returns Error::ConfigMismatch naming the offending field. The engine calls this on every construction path; wrappers may call it earlier to fail fast.

pub fn encode(&self, out: &mut Vec<u8>)

Appends the fixed binary form of the config to out — the config block of the snapshot. Layout, all little-endian, in field-declaration order: usize fields as u64, f32 fields as their IEEE 754 bits, then rrf_k/half_life_days/graph_depth as u32, db_uuid as a u128, then 8 reserved zero bytes; exactly ENCODED_LEN bytes. Encoding is lossless and canonical (float bits round-trip exactly).

pub fn decode(bytes: &[u8]) -> Result<Config, Error>

Decodes a config block written by Config::encode and runs Config::validate on the result.

The input is untrusted: a wrong length or nonzero reserved bytes are Error::Corrupt; out-of-range field values surface as the same Error::ConfigMismatch a hand-built config would get.

All size fields are stored as fixed-width u64, so the block is identical on 32-bit and 64-bit builds of the engine. A value that overflows this platform’s usize means the database was created with limits only a 64-bit address space can hold (e.g. max_bytes beyond 4 GiB on a wasm64 or native host) — the file is not corrupt, this host is too small for it, hence Error::ConfigMismatch.

Trait Implementations

impl Clone for Config

fn clone(&self) -> Config

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Config

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

Formats the value using the given formatter.

impl Default for Config

fn default() -> Config

The defaults table.

impl PartialEq for Config

fn eq(&self, other: &Config) -> bool

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Config