IBM i MCP Server

/** * @fileoverview Manages asynchronous context propagation using AsyncLocalStorage. * This module provides a mechanism to store and retrieve a `RequestContext` across * asynchronous operations, ensuring that critical metadata like `requestId` and trace * information is available throughout the entire call stack without prop drilling. * @module src/utils/internal/asyncContext * @see {@link src/utils/internal/requestContext.ts} for the definition of RequestContext. */ import { AsyncLocalStorage } from "node:async_hooks"; import type { RequestContext } from "./requestContext.js"; /** * The singleton `AsyncLocalStorage` instance for storing the `RequestContext`. * This holds the context for the duration of a single asynchronous operation, * such as an incoming tool call or a scheduled job. */ export const requestContextStore = new AsyncLocalStorage<RequestContext>(); /** * Retrieves the current `RequestContext` from the async local storage. * It is a synchronous call that depends on the execution context. * * @returns {RequestContext | undefined} The current `RequestContext` if it exists * in the current async context, otherwise `undefined`. */ export function getRequestContext(): RequestContext | undefined { return requestContextStore.getStore(); } /** * A higher-order function that runs a given function within a specified `RequestContext`. * This is the primary mechanism for establishing an async context for an operation. * * @template T The return type of the function to be executed. * @param {RequestContext} context - The `RequestContext` to set for the duration of the function's execution. * @param {() => T} fn - The function to execute within the context. * @returns {T} The result returned by the function `fn`. */ export function withRequestContext<T>(context: RequestContext, fn: () => T): T { return requestContextStore.run(context, fn); }