Struct ColumnarEntityIndex 

pub struct ColumnarEntityIndex { /* private fields */ }

Compact, sorted, binary-searched entity index. Columns are kept sorted by ids (strictly ascending, unique) so Self::lookup can binary_search.

Invariants (upheld by every constructor):

• ids.len() == starts.len() == lengths.len()
• ids is strictly ascending (hence unique)
• starts[i] / lengths[i] are the byte offset / byte length of ids[i], so lookup returns (start, start + length) to match the (start, end) tuple layout of EntityIndex.

Implementations

impl ColumnarEntityIndex

pub fn from_columns(ids: &[u32], starts: &[u32], lengths: &[u32]) -> Self

Build from the three delivered columns (setEntityIndex ingestion).

Verifies the id column’s ordering once, O(n): the pre-pass emits in whatever order it iterates (its own FxHashMap iteration order is arbitrary), so this cannot assume ascending. If the ids are already strictly ascending the columns are used as-is (no sort); otherwise a single stable argsort permutation is applied and duplicate ids are collapsed last-in-input-order-wins.

Mismatched column lengths yield an empty index (the wasm caller guards this too), so a malformed payload never panics a worker.

pub fn from_hashmap_consuming(map: EntityIndex) -> Self

Build from an already-scanned EntityIndex hashmap, CONSUMING it. On the wasm prepass path the map is ~436 MB at 19.1 M entities and the conversion runs while the whole source file is resident in the same <4 GiB heap; borrowing (from_hashmap) keeps the map alive across the copy AND the sort, spiking ~970 MB of transients.

Consuming drains into one interleaved Vec<(id, start, len)> (~229 MB) then sorts in place (sort_unstable; map keys are unique, so no stability/permutation buffer). Peak during the drain is map + rows capacity (~665 MB) until the map drops at end-of-loop; after that the sort is in-place and the final column split briefly overlaps rows + outputs (~458 MB) before rows drop. Still far below the borrowing path, and the steady-state index is ~229 MB.

pub fn from_hashmap(map: &EntityIndex) -> Self

Build from an already-scanned EntityIndex hashmap. The map is unique by construction (last-in-file-order-wins was applied by HashMap::insert), so this only sorts the entries. Prefer Self::from_hashmap_consuming when the map is no longer needed - it avoids holding map + copies concurrently (P1 review finding on #1689).

pub fn from_scan<T>(content: &T) -> Self

where T: AsRef<[u8]> + ?Sized,

Scan content and build the columns directly, replicating crate::build_entity_index’s HEADER-skipping / quoted-string scan and its last-in-file-order-wins duplicate handling — without ever materializing the intermediate FxHashMap. Used by the wasm lazy fallback when setEntityIndex was never called.

pub fn lookup(&self, id: u32) -> Option<(usize, usize)>

Binary-search the byte span of id. Returns (start, end) where end = start + length, exactly matching EntityIndex’s tuple, or None if the id is absent.

pub fn ids(&self) -> &[u32]

Sorted, unique id column (for re-emitting the entity-index event).

pub fn starts(&self) -> &[u32]

Byte-start column, parallel to Self::ids.

pub fn lengths(&self) -> &[u32]

Byte-length column, parallel to Self::ids.

pub fn len(&self) -> usize

Number of indexed entities.

pub fn is_empty(&self) -> bool

Whether the index is empty.