compact: summarize is a direct one-shot llm/stream call, not a loop step

The summarization request no longer dispatches agent/request — that seam
shapes the loop's conversation requests; a hand-built one-shot's
interception surface is llm/stream, like every other direct call. The
model comes from summarizationModel falling back to the agent's own. The
turn/step parameters existed on the compact seam only to feed the
agent/request dispatch and leave compactIfNeeded/compactRegion.

Groundwork for making every conversation request a pure function of the
session log (reconstructability RFC, this branch): the seam split keeps
the loop's request path as the single thing the log must explain.

Ported from worktree-prompt-prefix-stability (PR #162) where it was
review-converged; catalog and producer/consumer graphs regenerated.
This commit is contained in:
Tianyi Cui
2026-07-06 02:16:11 +08:00
parent 9c0cd392b9
commit 8510986909
9 changed files with 37 additions and 45 deletions
+2 -2
View File
@@ -18,8 +18,8 @@ Both methods are **abstract** — the backend owns the entire strategy (token es
| Member | Semantics |
|---|---|
| `compactIfNeeded(agent, turn, step, fullSystemPrompt, signal)` | Estimate the surface-derived history size; if over the backend's threshold, compact an older range via `compactRegion`, keeping recent context intact. Returns the `CompactionResult`, or `null` if nothing needed compacting. All parameters required — the loop's `agent/pre-step` checkpoint supplies the agent, lifecycle context, assembled `fullSystemPrompt`, and turn `signal`; router-aware summarizers can use the agent lifecycle context to route their own model call through `agent/request`. |
| `compactRegion(session, start, end, agent, turn, step, signal?)` | Forcibly summarize surface nodes `[start, end]` (inclusive seqs) into a single replacement node. **Throws** if a compaction is already in progress, if `start`/`end` aren't surface nodes, or if `start` is positioned after `end` on the surface. The range is a SURFACE-POSITION span, not a numeric seq interval — after a prior replace lands a fresh high-seq summary node at the shadowed range's position, surface order no longer tracks seq order. |
| `compactIfNeeded(agent, fullSystemPrompt, signal)` | Estimate the surface-derived history size; if over the backend's threshold, compact an older range via `compactRegion`, keeping recent context intact. Returns the `CompactionResult`, or `null` if nothing needed compacting. All parameters required — the loop's `agent/pre-step` checkpoint supplies the agent, assembled `fullSystemPrompt`, and turn `signal`. A backend's summarization request is a direct `ctx.llm.stream()` call (not a loop step), so per-call interception happens at `llm/stream`. |
| `compactRegion(session, start, end, agent, signal?)` | Forcibly summarize surface nodes `[start, end]` (inclusive seqs) into a single replacement node. **Throws** if a compaction is already in progress, if `start`/`end` aren't surface nodes, or if `start` is positioned after `end` on the surface. The range is a SURFACE-POSITION span, not a numeric seq interval — after a prior replace lands a fresh high-seq summary node at the shadowed range's position, surface order no longer tracks seq order. |
`compactIfNeeded` takes a required `signal`; `compactRegion`'s is optional. A backend that summarizes via `ctx.llm.stream()` **must** forward it into the call's `GenerateOptions.signal`, so an abort or fiber dispose tears down the in-flight summarization instead of leaving an orphaned model call running past the cancellation. The session being compacted comes from the agent context; the turn that the `compact/*` events belong to is recoverable from the log (the currently-open turn), so the backend stamps it from the log rather than trusting a caller-supplied value.