Files
deepseek-harness/packages/core/agent/src/inbox.ts
2026-07-30 15:35:18 +08:00

110 lines
4.0 KiB
TypeScript

/**
* Incremental projection of durable agent inbox events.
*
* @module @deepseek-ai/dsh-agent/inbox
*/
import type { Session, SessionEventMap, UserMessage } from '@deepseek-ai/dsh-session'
/** One of the two ordered pending-message lists owned by an agent. */
export type InboxTarget = 'next-turn' | 'next-step'
/** Mutable state privately owned by an {@link Inbox}. */
type InboxState = Record<InboxTarget, UserMessage[]>
/** A replay-once projection that incrementally consumes later inbox splices. */
export class Inbox {
private readonly state: InboxState = { 'next-turn': [], 'next-step': [] }
constructor(private readonly session: Session) {
for (const event of session.events.slice(session.header.seedLength ?? 0)) {
if (event.type !== 'agent/inbox/spliced') continue
try {
this.apply(event.data)
} catch (error: unknown) {
throw new Error(`invalid persisted inbox splice at session seq ${event.seq}`, { cause: error })
}
}
}
/** Prompts awaiting individual turns. */
get nextTurn(): readonly UserMessage[] {
return this.state['next-turn']
}
/** Input awaiting admission at a step boundary. */
get nextStep(): readonly UserMessage[] {
return this.state['next-step']
}
/** Whether either pending-message list contains work. */
get hasPending(): boolean {
return this.nextTurn.length > 0 || this.nextStep.length > 0
}
/**
* Apply standard splice semantics and durably record the normalized result.
* @param target - pending list to mutate.
* @param start - splice position.
* @param deleteCount - maximum number of messages to remove.
* @param inserted - messages to insert at the resolved position.
* @param outcome - terminal disposition of removed messages.
* @returns messages removed by the splice.
*/
splice(
target: InboxTarget,
start: number,
deleteCount: number,
inserted: UserMessage[],
outcome?: 'admitted' | 'canceled',
): UserMessage[] {
const inbox = this.state[target]
const offset = Math.trunc(start) || 0
const actualStart = offset < 0
? Math.max(inbox.length + offset, 0)
: Math.min(offset, inbox.length)
const actualDeleteCount = Math.min(
Math.max(Math.trunc(deleteCount) || 0, 0),
inbox.length - actualStart,
)
if (actualDeleteCount === 0 && inserted.length === 0) return []
const resolvedOutcome = outcome ?? (actualDeleteCount > 0 ? 'canceled' : undefined)
const splice = {
target,
start: actualStart,
...(actualDeleteCount === 0 ? {} : { removedCount: actualDeleteCount }),
inserted,
...(resolvedOutcome === undefined ? {} : { outcome: resolvedOutcome }),
}
this.validate(splice)
const event = this.session.append('agent/inbox/spliced', splice)
return inbox.splice(actualStart, actualDeleteCount, ...event.data.inserted)
}
/** Apply one normalized durable splice to the projection. */
private apply(splice: SessionEventMap['agent/inbox/spliced']): UserMessage[] {
this.validate(splice)
const inbox = this.state[splice.target]
return inbox.splice(splice.start, splice.removedCount ?? 0, ...splice.inserted)
}
/** Validate one normalized splice against the current projection. */
private validate(splice: SessionEventMap['agent/inbox/spliced']): void {
const inbox = this.state[splice.target]
const removedCount = splice.removedCount ?? 0
if (!Number.isSafeInteger(splice.start) || splice.start < 0 || splice.start > inbox.length
|| !Number.isSafeInteger(removedCount) || removedCount < 0
|| splice.start + removedCount > inbox.length) {
throw new Error('invalid inbox splice')
}
const candidate = inbox.toSpliced(splice.start, removedCount, ...splice.inserted)
const ids = new Set<string>()
for (const message of splice.target === 'next-turn'
? [...candidate, ...this.nextStep]
: [...this.nextTurn, ...candidate]) {
if (ids.has(message.id)) throw new Error(`message "${message.id}" is already pending`)
ids.add(message.id)
}
}
}