The `alpha-id index --pack` writer logic — store-completeness check, row
collection in corpus order, header derivation (dim/corpus_name/corpus_sha256/
n_rows), and the write — lived inline in main, leaving the header construction
outside library test reach (covered only end-to-end via the pack CLI tests).
This extracts it into packed::pack_from_store, returning
PackOutcome { Packed(PackedHeader), Incomplete { cached, total } }. main's pack
branch now just loads entries, calls the fn, and matches the outcome onto the
same stderr messages and exit code 2 as before.
Behaviour is unchanged: the stderr lines ("store incomplete: N of M entries
embedded; run `index --full --confirm` first" and "packed N rows × D dims →
path") and the exit-2 refusal are byte-identical, and the four existing pack
CLI tests (pack_refuses_incomplete_store_exit_2, pack_writes_file_from_complete_store,
cli_packed_file_loads_back_as_ok_index, cli_packed_rows_are_in_corpus_order)
stay green unchanged as the behaviour-parity guard. Two new unit tests now
exercise the header construction directly without spawning the binary: a
complete store yields PackOutcome::Packed with the expected n_rows/dim/
embed_model/corpus_sha256 and writes the file; an incomplete store yields
PackOutcome::Incomplete { cached, total } and writes nothing.
Minor improvement folded in: the old inline `store.get(...).expect("cached
vector")` is now a propagated AppError inside pack_from_store rather than a
panic (the branch stays unreachable — the complete-store precondition is
checked first — so parity holds).
This is the debt tidy the cycle-close audit deferred (architect [low] finding).
87 tests green.
closes#5
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The semantic index was ~90 896 per-entry files (index/embeddings/<safe-model>/
<sha256>.f32), a deployment liability: the file count — not the 356 MB — is
hostile to container layers, object storage, and Git-LFS, and Pipeline::load
opened every one individually. This packs a complete per-file store into one
self-describing matrix file loaded in a single read.
New src/packed.rs owns the format: 4-byte magic "AIPK", u32 LE format_version,
u32 LE header length, a JSON PackedHeader {n_rows, dim, embed_model,
corpus_sha256, corpus_name}, pad to a 4-byte boundary, then row-major
little-endian f32 payload in corpus order (row i = corpus entry i). write_packed
is atomic (temp+rename); read_packed rejects a wrong magic, a newer-than-
supported version, a malformed header, or a payload length inconsistent with
n_rows×dim. corpus_sha256 hashes the raw corpus file bytes.
Pipeline::load now calls a free fn load_packed_or_store(cfg, entries) that
prefers the packed file and falls back to today's all-or-nothing per-file store,
reporting which path it took via a new IndexStatus {Ok, Absent, Mismatch}
carried into Diagnostics. `alpha-id index --pack` writes the file from a
complete store (refusing an incomplete one with exit 2), recording corpus_sha256
+ embed_model in the header as the artifact-binding data.
Iteration boundary (deliberate): this is iteration 1 of the packed-versioned-
bundle cycle. load_packed_or_store validates the packed file STRUCTURALLY only
(magic/version/payload length via read_packed, plus n_rows == entries.len());
it does NOT yet compare the header's corpus_sha256/embed_model against the live
config, and IndexStatus::Mismatch fires only on structural corruption. The
load-time mismatch warning, the index= token on the diagnostics line, and the
Hybrid-degrade-names-reason wiring are iteration 2 (issue #4), which consumes
the binding data this commit writes. The per-file store is untouched — it stays
the build/resume path; the packed file is an additive serve-path artifact.
mmap was considered and rejected: the brute-force full-scan cosine search
touches every row per query, so memory-mapping yields no runtime benefit over a
single read and would add an unsafe dependency (spec § Out of scope).
Verification: cargo test green (61 tests; 9 new — 3 format round-trip/hash/bad-
magic, 4 load-path incl. packed-beats-store and structural n_rows mismatch, 2
--pack CLI incl. exit-2 refusal). An end-to-end seam test writes the packed
file via the CLI, removes the per-file store, and asserts the pipeline builds
its index from the packed file alone as IndexStatus::Ok (#3 acceptance b).
Spec: docs/specs/2026-05-31-packed-versioned-index-bundle.md
Plan: docs/plans/2026-06-01-packed-versioned-bundle-iter1.md
closes#3
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Brummel