Files
deepseek-harness/packages/core/agent-loop/src/request-log.ts
2026-07-13 23:56:10 +08:00

70 lines
3.1 KiB
TypeScript

/**
* Per-loop-instance transmission bookkeeping for the reconstructability
* contract: which header event to append before a request so the session log
* always explains the request (the reconstructability RFC). The loop is
* otherwise transmission-stateless — the comparison baseline is the log's own
* folded header (`Session.requestHeader()`), so resume and fork need no
* special path: a fresh loop instance simply logs a `'resume'` snapshot on
* its first request and full changed-header snapshots from there.
*
* @module dsh-agent-loop/request-log
*/
import { headerEquals } from '@deepseek-ai/dsh-session'
import type { EpochHeader, Session } from '@deepseek-ai/dsh-session'
import type { Message } from '@deepseek-ai/dsh-llm'
/** Per-loop-instance bookkeeping: whether THIS instance has logged a header yet. */
export interface TransmissionLog {
/** True once this loop instance appended its anchoring `request/header` snapshot. */
loggedHeader: boolean
/**
* The instance's composed session prefix (the `agent/session-prefix`
* waterfall's deep-frozen product), cached on the instance's first
* request-building step and reused verbatim for every request it sends —
* the structural guarantee that the prefix never changes mid-session.
* `undefined` until composed.
*/
sessionPrefix?: Message[]
}
/**
* Fresh bookkeeping for a newly-started loop instance.
* @returns state with `loggedHeader` false, so the instance's first request appends an anchoring snapshot.
*/
export function createTransmissionLog(): TransmissionLog {
return { loggedHeader: false }
}
/**
* Append whatever header event this request owes the log, so folding the log
* reproduces the header the request was built under. Exactly one of three
* things happens:
*
* 1. This loop instance has not logged a header yet → a full `request/header`
* snapshot anchors the fold: reason `'initial'` when the log has no header
* events at all (a new conversation), `'resume'` when it does (process
* restart, fork seed — the boundary itself is a recorded fact, so the
* snapshot is appended even when nothing changed).
* 2. The header equals the folded baseline → nothing; the log already
* explains this request.
* 3. It differs → a full snapshot with reason `'change'`.
*
* @param session - the session whose log explains the request.
* @param state - this loop instance's bookkeeping (mutated on first log).
* @param header - the canonical header the request will ACTUALLY use
* (post-`agent/request`).
*/
export function recordRequestHeader(session: Session, state: TransmissionLog, header: EpochHeader): void {
if (!state.loggedHeader) {
session.append('request/header', { header, reason: session.requestHeader() === undefined ? 'initial' : 'resume' })
state.loggedHeader = true
return
}
// This instance logged a snapshot, so the fold is necessarily defined.
// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
const baseline = session.requestHeader()!
if (headerEquals(baseline, header)) return
session.append('request/header', { header, reason: 'change' })
}