#[non_exhaustive]pub struct Config {Show 28 fields
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,
}Expand description
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)§
This struct is marked as non-exhaustive
Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.dim: usizeVector dimension; 0 disables the vector layer entirely. Max 4096.
max_bytes: usizeCeiling for each byte pool — not for their sum.
Every pool the engine builds (the arenas’ pages, the text and metadata
blob heaps, the tag and posting chunk pools, the vector pool) is given
this same figure as its own limit and refuses to grow past it with
Error::CapacityExceeded. A database’s total therefore reaches
several times this number; the one that binds first is whichever pool
the workload fills, normally the fact texts.
The default is the wasm32 passport rather than a capacity judgement: it
keeps every pool addressable where usize is 32 bits, so a database
written anywhere opens anywhere. Raising it is supported and costs
exactly that portability — a 32-bit host then refuses the file with a
typed ConfigMismatch, not with corruption.
max_text: usizeMaximum fact text length in bytes.
max_blob: usizeMaximum single blob length in bytes.
shards_facts: usizeShard count of the facts arena (power of two, ≤ MAX_SHARDS).
Engine-managed. The five shard counts describe how an existing file
is laid out, not a preference: a new database starts at MIN_SHARDS,
opening one adopts whatever the snapshot records, and maintain moves
the layout as the data grows or shrinks. Setting one here only affects a
database being created, and the next maintenance pass will overrule it.
shards_entities: usizeShard count of the entities arena. See Config::shards_facts.
shards_edges: usizeShard count of each edge arena. See Config::shards_facts.
shards_temporal: usizeShard count of the temporal arena. See Config::shards_facts.
shards_postings: usizeShard count of the postings arenas. See Config::shards_facts.
bm25_k1: f32BM25 k1 (term-frequency saturation).
bm25_b: f32BM25 b (length normalization), in [0, 1].
rrf_k: u32The RRF rank constant (score += w / (rrf_k + rank)).
w_bm25: f32RRF weight of the lexical (BM25) source.
w_vec: f32RRF weight of the vector source.
w_graph: f32RRF weight of the graph source.
w_time: f32RRF weight of the temporal-range source.
w_recency: f32Strength of the recency boost (0 disables it).
half_life_days: u32Recency half-life in days.
graph_depth: u32Graph expansion depth limit.
graph_decay: f32Per-hop weight decay of graph candidates, in (0, 1].
similar_cos: f32Cosine threshold for vector-based similar-detection, in [0, 1].
similar_jaccard: f32Jaccard threshold for lexical similar-detection, in [0, 1].
hnsw_m: usizeHNSW: neighbors per node on upper levels.
hnsw_m0: usizeHNSW: neighbors per node on level 0.
hnsw_ef_construction: usizeHNSW: beam width during construction.
hnsw_ef_search: usizeHNSW: default beam width during search (per-query override exists).
flat_to_hnsw: usizeVector count at which maintain switches Flat → HNSW.
db_uuid: u128Database 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§
Source§impl Config
impl Config
Sourcepub fn validate(&self) -> Result<(), Error>
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.
Sourcepub fn encode(&self, out: &mut Vec<u8>)
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).
Sourcepub fn decode(bytes: &[u8]) -> Result<Self, Error>
pub fn decode(bytes: &[u8]) -> Result<Self, 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.