TaskGraph

The task graph: every live task of the Session (pending, running, waiting, completing) with its owner edge, the conversations it owns and its durable status, without checkpoint or outcome payloads (pi spec §9.5). A terminal task leaves the graph.

import { TaskGraph } from "@effective-harness/core"
import * as Effect from "effect/Effect"

const program = Effect.gen(function* () {
  const graph = yield* TaskGraph.get
  for (const node of Object.values(graph.tasks)) console.log(node.kind, node.id, node.state.status)
})

Unlike Scheduler.inspect, the graph is derived from committed records only, so it reads the same with the scheduler paused or closed, and a watch advances it from commit publications.

Since v0.0.0

---

utils

Frame (interface)

The graph after one commit that changed it.

Signature

export interface Frame {
  readonly seq: Seq
  readonly value: TaskGraph
  /** Operations from the previously delivered value; one root `replace` after an overflow. */
  readonly ops: JsonPatch.JsonPatch
}

Source

Since v0.0.0

Node (interface)

Signature

export interface Node {
  readonly id: TaskId
  readonly kind: string
  readonly conversationId: ConversationId
  /** Owner task; absent for a conversation-owned task. */
  readonly owner?: TaskId
  readonly background: boolean
  readonly abortRequested: boolean
  readonly state: NodeState
  /** Conversations this task owns, in ID order. */
  readonly conversations: ReadonlyArray<ConversationId>
}

Source

Since v0.0.0

NodeState (type alias)

A live task’s durable status; phase is its checkpoint’s tag.

Signature

type NodeState =
  | { readonly status: "pending" | "running"; readonly phase: string }
  | {
      readonly status: "waiting"
      readonly phase: string
      readonly on: ReadonlyArray<TaskId>
      readonly policy: JoinPolicy
    }
  /** An outcome held until the task's ordinary owned work drains. */
  | { readonly status: "completing"; readonly outcome: TaskOutcome["status"] }

Source

Since v0.0.0

TaskGraph (interface)

Signature

export interface TaskGraph {
  /** Every live task, keyed by its decimal ID. */
  readonly tasks: { readonly [id: string]: Node }
}

Source

Since v0.0.0

Watch (interface)

Signature

export interface Watch {
  /** The graph at acquisition. */
  readonly value: TaskGraph
  /**
   * Every later commit that changed a node, in order. When more than `Session.MaxPendingWatchFrames` frames are
   * waiting, they collapse into one root replacement. Ends when the Session closes.
   */
  readonly changes: Stream.Stream<Frame>
}

Source

Since v0.0.0

get

The current graph, read on the commit line.

Signature

declare const get: Effect.Effect<TaskGraph, StorageFailure | SessionPoisoned, Session>

Source

Since v0.0.0

watch

Watch the graph. The value and the registration for later commits are captured atomically on the commit line; the watch lives until its scope closes.

Signature

declare const watch: Effect.Effect<Watch, StorageFailure | SessionPoisoned, any>

Source

Since v0.0.0