---
model: openai/gpt-5.6-sol
service: opencode
session: ses_0799212ebffe42arY96czXn89F
timestamp: 2026-08-05T19:50:01Z
git_ref: f0f3c806
scope: code
substantive: true
raw_file: 20260805T195001Z_f0f3c806_prompt_io.raw.md
---

## Prompt

Inspect the completed NVDA 60s SHM backfill before workspace restart, explain
the persistent zero region, and continue fixing the indexing logic so sparse
IB history does not leave physical null reservations.

## Response summary

Captured a 42,720-row live SHM null span whose valid margins shared the same
timestamp. Replaced wall-clock row reservation with actual provider-boundary
placement, fixed stale SHM first-index, endpoint insertion and field-map
semantics, published the final storage prepend, and added a full multi-frame
`tsdb_backfill()` regression using a real `ShmArray`.

## Files changed

- `piker/tsp/_history.py` - contiguous provider and NativeDB prepends.
- `tests/test_history_backfill.py` - sparse multi-frame SHM regression.

## Human edits

None - generated output incorporates the user's live observations.