worker.ts (5854B)
1 // Test-only JS evaluator driver; excluded from the production site. 2 import { sourceText } from '../compiler.js'; 3 import { compileExpression } from './expression.js'; 4 import { resumeValue } from '../io.js'; 5 import { publishedBundle } from '../published-bundle.js'; 6 import { exportTree, treeFormat } from '../tree-export.js'; 7 import { BROWSER_BUDGET, collectionPolicy, PACKAGE_COLLECTION } from '../execution.js'; 8 import { Graph } from '../graph.js'; 9 import { bundleHash, loadBundle, type Bundle, type BundleHash } from '../bundle.js'; 10 import { literals, makeLiteral, outputType, view } from '../codecs.js'; 11 import { runIO } from '../io.js'; 12 import type { ClientMessage, WorkerMessage, RequestId } from '../protocol.js'; 13 const scope = globalThis as unknown as { postMessage(message: WorkerMessage): void; onmessage: ((event: MessageEvent<unknown>) => void) | null }; 14 const send = (message: WorkerMessage): void => scope.postMessage(message); 15 const running = (): void => send({ type: 'state', state: 'running' }); 16 let phase: 'empty' | 'loading' | 'ready' | 'running' | 'done' = 'empty'; 17 let graph: Graph | undefined, exports: Map<string, import('../graph.js').NodeId> | undefined; 18 let stored: { hash: BundleHash; bundle: Bundle; bytes: Uint8Array } | undefined; 19 let requestId = 0; 20 let pending: { id: RequestId; kind: 'step' | 'input'; resolve(value: string): void; reject(error: Error): void } | undefined; 21 function request(kind: 'step' | 'input'): Promise<string> { 22 if (pending) throw new Error('Driver already waiting'); 23 const id = ++requestId as RequestId; 24 return new Promise((resolve, reject) => { pending = { id, kind, resolve, reject }; send({ type: 'state', state: kind, id }); }); 25 } 26 async function load(hash: BundleHash, localId: string | undefined): Promise<void> { 27 phase = 'loading'; running(); 28 const loaded = await publishedBundle(hash, localId); 29 const { bundle, source } = loaded; 30 stored = loaded; 31 const budget = BROWSER_BUDGET; 32 graph = new Graph(budget, collectionPolicy(budget, PACKAGE_COLLECTION.threshold)); exports = loadBundle(graph, bundle); 33 phase = 'ready'; 34 send({ type: 'loaded', hash, exports: bundle.exports, nodes: bundle.nodes.length, metadata: bundle.metadata, source }); 35 } 36 async function run(message: Extract<ClientMessage, { type: 'run' }>): Promise<void> { 37 if (phase !== 'ready' || !graph || !exports) throw new Error('Load a bundle before running'); 38 phase = 'running'; running(); 39 const fn = message.expression === undefined ? exports.get(message.export) : await compileExpression(graph, exports, message.expression); 40 if (fn === undefined) throw new Error('Unknown export'); 41 if (message.mode !== 'pure' && message.mode !== 'io') throw new Error('Unsupported execution mode'); 42 const type = outputType(message.output), args = literals(message.arguments).map(value => makeLiteral(graph!, value)); 43 let result = message.expression === undefined ? graph.apply(fn, args) : fn; 44 graph.collect([result]); // Exclusive one-run session: only this application remains owned. 45 if (message.mode === 'io') result = await runIO(graph, result, { 46 async before(event) { send({ type: 'trace', phase: 'before', event }); if (message.step === true) await request('step'); running(); }, 47 after(event) { send({ type: 'trace', phase: 'after', event }); }, 48 write(text) { send({ type: 'output', text }); }, read() { return request('input'); }, running, 49 }, true); 50 const displayed = view(graph, result, type); 51 phase = 'done'; send({ type: 'done', result: displayed, stats: graph.stats }); 52 } 53 scope.onmessage = ({ data }) => { 54 if (!data || typeof data !== 'object' || Array.isArray(data)) return; 55 const message = data as Record<string, unknown>; 56 if (message['type'] === 'resume') { 57 if (!pending || message['id'] !== pending.id) return; 58 const value = resumeValue(pending.kind, message['value']); 59 if (value === undefined) return; 60 const waiter = pending; pending = undefined; waiter.resolve(value); 61 return; 62 } 63 if (message['type'] === 'download' && phase === 'ready' && stored) { 64 send({ type: 'downloaded', hash: stored.hash, bytes: stored.bytes }); return; 65 } 66 if (message['type'] === 'export' && phase === 'ready' && stored) { 67 try { 68 if (typeof message['export'] !== 'string' || message['export'].length > 512) throw new Error('Invalid export selection'); 69 const format = treeFormat(message['format']); 70 const file = exportTree(stored.bundle, message['export'], format); 71 send({ type: 'exported', hash: stored.hash, export: message['export'], format, file }); 72 } catch (error) { send({ type: 'export-error', message: error instanceof Error ? error.message : String(error) }); } 73 return; 74 } 75 let operation: Promise<void>; 76 try { 77 if (message['type'] === 'load' && phase === 'empty') { 78 const localId = message['localId']; 79 if (localId !== undefined && (typeof localId !== 'string' || localId.length > 128)) throw new Error('Invalid catalogue ID'); 80 operation = load(bundleHash(message['hash']), localId); 81 } else if (message['type'] === 'run' && phase === 'ready') { 82 if (typeof message['export'] !== 'string' || message['export'].length > 512) throw new Error('Invalid export selection'); 83 operation = run({ type: 'run', export: message['export'], arguments: message['arguments'], 84 ...(message['expression'] === undefined ? {} : { expression: sourceText(message['expression']) }), 85 output: outputType(message['output']), mode: message['mode'] as 'pure' | 'io', step: message['step'] === true }); 86 } else return; // A Worker owns exactly one load and one run, no racing sessions. 87 } catch (error) { operation = Promise.reject(error); } 88 operation.catch((error: unknown) => { phase = 'done'; send({ type: 'error', message: error instanceof Error ? error.message : String(error) }); }); 89 };