The mmap-vector backend was a 2.x-era accelerator for the JS HNSW read path:
a native provider registered under 'vectorStore:mmap' supplied a single-file
mmap'd vector store, and JsHnswVectorIndex tried it before per-entity storage
reads with lazy write-back migration.
In the 8.0 provider world nothing registers that key — the native plugin's
3.0 line replaces the entire vector index under the 'vector' provider key
(vectors live inside its own index file), and the open-core path never had
an mmap provider. The wiring is unreachable; per the no-unwired-code rule
it goes away:
- src/hnsw/mmapVectorBackend.ts deleted (175 LOC)
- wireMmapVectorBackend() + its init call site removed from brainy.ts
- VectorStoreMmapProvider + VectorStoreMmapInstance contracts removed
from plugin.ts
- JsHnswVectorIndex loses the vectorBackend field, setVectorBackend(),
and the mmap-first branches in getVectorSafe/preloadVectors — the
storage + UnifiedCache path is now the single read path
- tests/unit/hnsw/mmap-vector-backend.test.ts deleted
The 7.x line keeps the wiring and got the capacity-NaN bugfix as 7.31.3
(see the platform handoff mmap thread). EntityIdMapperProvider stays — the
connections codec and the id mapper still implement it.
1403/1403 tests, build clean.