geekinney/ekp
1
0
Fork 0
Code Issues Pull Requests Actions 1 Packages Projects Releases Wiki Activity
83352c4571
ekp/.phrase/phases/phase-kp-overhaul-20260726/issue_stable_live_edit_transaction_20260729.md
Kinneyzhang 83352c4571 feat!: add source-clean live buffer layout 
Replace the physical ekp-region renderer with ekp-buffer text-property projection backed by shared semantic layout plans and stable live-edit transactions.

Optimize the C-backed resize hot path, and add deterministic performance, ERT, GUI, fuzz, release, and documentation coverage for task017 through task032.

BREAKING CHANGE: require ekp-buffer instead of ekp-region and rename module-owned ekp-region-* settings to ekp-buffer-*.
2026-07-30 01:07:25 +08:00

4.4 KiB
Raw Blame History

Issue: Stable Live Edit Transaction 2026-07-29

issue019 [ ] Per-edit frontier replanning destabilizes live projection and cannot restore reversible edits exactly

  • Status: Implemented and developer-verified by task031; awaiting the required user-visible confirmation.
  • Summary: The current live path makes one frontier simultaneously own the latest edit, the natural suffix, and projection reuse. Before every edit it clears the touched projected line and every following line; after every edit it replans the complete hard line. This makes unrelated rows move during continuous input and turns narrow append latency into a symptom of the same ownership error.
  • Environment: Graphical Emacs 30.2; ekp-auto-justify-mode; long mixed Latin/CJK hard lines with an installed live prefix.
  • Repro:
    1. Type a hard line until multiple visual rows exist.
    2. Continue typing within the unfinished row, or edit a previously projected middle row.
    3. Observe earlier/succeeding rows and the owned text properties after each source change.
    4. Delete a projected space and insert the identical space again.
  • Expected vs Actual:
    • Expected: ordinary same-row input leaves the committed projection untouched. A middle-row edit opens one local dirty island while unaffected break anchors remain installed. Small changes are absorbed by existing glue/native wrapping; local words move only when the dirty row no longer fits. Restoring the exact source restores the exact projection immediately.
    • Actual: before-change invalidates the touched line and its complete projected suffix. after-change moves frontier, runs or reuses a whole-hard-line plan, and republishes immediately. The transaction stores only an old paragraph marker and deleted fragment, so it cannot restore a committed baseline as a first-class state transition.
  • Root Cause: frontier conflates three independent owners: source-edit location, unprojected edit boundary, and plan/projection reuse boundary. Signature diffing reduces writes after a plan is chosen, but cannot prevent global optimal breaks from changing when a new plan is computed after every key.
  • Required Outcome:
    • committed projection owns the last published source/plan/signatures/spans;
    • a dirty edit transaction snapshots that baseline and owns only the affected local island;
    • ordinary same-row edits do no whole-hard-line DP and do not rewrite unaffected projection;
    • crossing a native visual-row boundary atomically replans the completed hard-line prefix, leaving the new current row natural;
    • the next real edit elsewhere, hard newline/paragraph completion, explicit refill, or width/font/layout-context change is a commit event;
    • point-only motion performs zero planning, cache, property, or layout work;
    • a reversible edit restores source and the complete owned projection equal-including-properties without depending on a best-effort replan;
    • completed paragraphs still use the existing globally optimal core DP;
    • no overlays or source layout characters are introduced.
  • Fix: task031 deletes frontier-owned immediate publication. Committed live state now owns source/key/plan/signatures/prefix/spans; one edit transaction snapshots that state and marker offsets, naturalizes only its dirty island, restores exact baselines directly, and permits replanning only at native-row or structural commit events. Static lazy-reflow chunks exclude the active paragraph. The core DP and ekp.el are unchanged.
  • Verification: Focused public-path regressions were observed red before implementation and green afterward. Final buffer/default/random/isolated ERT runs pass 99/99, 188/188, 188/188, and 188/188; C/Elisp fuzz passes 300/300; compile, checkdoc, package-lint, release, and local dictionary gates pass. The reviewed dynamic run /private/tmp/ekp-stable-transaction-final5-2BFryc is PASS with 55 checkpoints, no failed assertion, a completed run-end, and no black segment or visual noise. Same-row and point-motion benchmark scenarios perform zero plans; 291 appends now contain only 15 structural plans.
  • User Confirmation: Required after temporal GUI evidence is delivered.
  • Resolved At: Unresolved.
  • Resolved By: task031 developer verification; user confirmation pending.
  • Commit: Pending.