placement-worker

Type Aliases

CacheEntryJob

type CacheEntryJob = object;

Defined in: tar/src/placement-worker.ts:46

Unpack the tarball in a vlt cache entry file into target. The worker reads the file itself, so the main thread never holds or copies the body.

Type declaration

PlacementJob

type PlacementJob = 
  | UnpackJob
  | CacheEntryJob;

Defined in: tar/src/placement-worker.ts:54

PlacementReply

type PlacementReply = 
  | {
  id: number;
  result: true;
 }
  | {
  code: string;
  error: string;
  id: number;
  stack: string;
 }
  | {
  ready: true;
};

Defined in: tar/src/placement-worker.ts:61

A worker's reply for job id: true once unpacked, or the message, stack and errno code of the error thrown, which the pool rebuilds into an Error so a worker failure looks like the inline call failing.

Type declaration

{ id: number; result: true; }

{ code: string; error: string; id: number; stack: string; }

{ ready: true; }

ReplyPort

type ReplyPort = object;

Defined in: tar/src/placement-worker.ts:68

A port that takes a PlacementReply; the real one is parentPort.

Type declaration

UnpackJob

type UnpackJob = object;

Defined in: tar/src/placement-worker.ts:31

Unpack a tarball into target. The bytes arrive as an ArrayBuffer transferred from the main thread.

Type declaration

Variables

__CODE_SPLIT_SCRIPT_NAME

const __CODE_SPLIT_SCRIPT_NAME: string;

Defined in: tar/src/placement-worker.ts:25

Unpacking a tarball is synchronous work the main thread cannot afford: inflating it, parsing it and writing its files. While the main thread does that, no registry response is read, no manifest is parsed and no node is placed in the graph. A PlacementPool runs this script as a worker thread so several packages are unpacked at once, across cores, and the main thread stays free to keep the network busy.

Hardlinking a global store entry stays on the main thread: it is a fraction of a millisecond per package, and on a two-core machine the boot of the workers and the round trips never paid for themselves (measured: +48% on the placement phase of a warm install).

The build emits it as its own bundled file: the exported __CODE_SPLIT_SCRIPT_NAME is the path to spawn (the source .ts in dev and test, the built .js in the bundle), and handleJob is the per-message handler, exported so it can be tested without a live worker.

Functions

handleJob()

function handleJob(port, job): void

Defined in: tar/src/placement-worker.ts:73

Run one job and post the result (or its error) back.

Parameters

Returns

void