refactor(compact): store tool-pairing balance once per surface cut

toolPairingBalancedAfter previously answered by resolving a cached
positional successor and reading its before-balance, with a null-successor
depth fallback. Both queries are the same prefix property sampled at
adjacent cuts, so the cache now holds one per-cut balance sequence
(N nodes -> N+1 cuts) plus a seq->position index; before/after differ
only by a cut offset. The successor map, the duplicate rebuild/extend
fold loops, and the non-null assertion are gone, and the running counter
is named inProgressToolCalls. Docs describing the successor mechanism
are updated in place.
This commit is contained in:
Hypatia May
2026-07-16 11:40:00 +08:00
parent 3cccecee0a
commit 2793325df0
6 changed files with 51 additions and 79 deletions

View File

@@ -6,7 +6,7 @@ Status: proposed
The session log maintains two representations that cost more machinery than their consumers require: a pseudo-linked surface and custom request-header deltas.
`SurfaceManager` stores the same order in an array, a seq map, and mutable `prev`/`next` links. Production never reads `prev`; compact's sole `next` read is the successor of an array position. Replacement already uses `indexOf`, so the links do not make its dominant operation constant-time. A seq array with linear replacement lookup has the same asymptotic replacement cost and one representation to validate.
`SurfaceManager` stores the same order in an array, a seq map, and mutable `prev`/`next` links. Production never reads either link: compact's tool-pairing balance answers from per-cut balances cached in surface order. Replacement already uses `indexOf`, so the links do not make its dominant operation constant-time. A seq array with linear replacement lookup has the same asymptotic replacement cost and one representation to validate.
The request-header subsystem implements a custom system/tool delta codec and transmission-decision layer even though its contract says deltas are an encoding optimization, not a reconstructability requirement. Retaining the initial/resume full snapshot at each loop-instance boundary, then writing a canonical full `request/header` whenever that instance's assembled header changes, preserves replay while deleting `SystemDelta`, `ToolsDelta`, round-trip fallback, and the durable `request/header-delta` variant. Codec-only vocabulary disappears with the codec, not because its individual arms were invalid.