Beagle SCM

JS-086: shared/store.js god module split + ref writers take reader.shard

store.js is ~650 lines carrying five responsibilities: object store, LSM index, ref read, ref write, and tree descent. The ref WRITERS (createShard/set/tombstone, folded in from a former refs.js) are free functions exported separately from open()'s reader and key on a RAW fs shard path — so every mutating verb peels reader.shard off the reader and hands it back, leaking the on-disk layout into the verbs. Method: Issues.

Input

Context

• store.js:1-651 — header (:1-39) lists object read + ref read + ref writers (:9) + tree descent (descendPath) in ONE module.
• store.js:625 set(shard,key,sha) / :632 tombstone(shard,key) / :618 createShard(shard,key) take a raw fs path, not a reader.
• put.js:62 store.set(k.shard, branch, cur.sha); :75-76 store.createShard(k.shard,branch) + store.set(k.shard,…).
• delete.js:230 store.tombstone(k.shard, target).
• post.js:242 commitM.writePack(reader.shard,…); :246 advanceRef(reader, reader.shard, …) — shard threaded twice.

Goals

• Split store.js: shared/store/objects.js (object store + LSM index) + shared/refs.js (ref read + write), thin store.js facade re-exporting if callers need one import.
• Ref writers take the reader/store handle and derive shard internally: store.set(reader,key,sha) etc.
• Verbs (PUT, POST, delete) stop touching .shard.

Constraints

• libabc + libdog ONLY; on-disk refs ULOG format unchanged.
• Byte-identical .be/refs across put/post/delete repeats (the DIS-050 dedup at put.js:68-72 must still hold).
• Keep parity with keeper/REFS.c set/tombstone semantics.

WIP

Design decisions

• Reader already holds shard; have set/tombstone read reader.shard so callers never name the path.
• Facade store.js keeps open + re-exports refs writers to bound the blast radius of the require-site churn.

TODOs

• Repro-first: parity test asserting .be/refs bytes unchanged across put/post/delete before and after the split.
• Carve objects.js + refs.js out of store.js; add facade.
• Change writer signatures to (reader,key,sha); update put.js:62 /75-76, delete.js:230, post.js advanceRef (:246) call sites.

Blockers and bummers

• Touches PUT + POST + delete — land behind their parity gates.

• 2026-07-07 audit: STILL OPEN (line refs shifted) — no shared/refs.js/store/objects.js split exists; shared/store.js:633 createShard/:640 set/:647 tombstone still take a raw shard; callers still peel .shard (put.js:90,104; delete.js:272; post.js:685,692).
• 2026-07-10 revision: still OPEN — store.js 666 lines, no split; set/createShard/tombstone raw shard (store.js:633,640,647); callers put.js:95,108,109 delete.js:279 post.js:688,695

Outcome

• (pending)