feed-wasm-host.mjs raw

   1  // feed-wasm-host.mjs — Worker bootstrap for feed.wasm.
   2  import {
   3    makeCoreHelpers, makeWasi, makeCommonBridge, computeBuildHash,
   4  } from './bridge-common.mjs';
   5  
   6  let mem, xp;
   7  const _sabTable = new Map(), _sabSeqRef = { value: 0 };
   8  const _spawnedWorkerChans = new Map();
   9  const _wasmUrlRef = { value: null }, _buildHashRef = { value: null };
  10  const h = makeCoreHelpers(() => mem, () => xp);
  11  const { readStr, writeStr, writeI32, readBytes, writeBytes, cb0, cbs, cbb, cbdata } = h;
  12  let _workerMsgCBID = 0, _consumerMsgCBID = 0;
  13  const _pending = [];
  14  
  15  function jsonEsc(s) {
  16    return String(s).replace(/\\/g,'\\\\').replace(/"/g,'\"').replace(/\n/g,'\\n').replace(/\r/g,'\\r').replace(/\t/g,'\\t');
  17  }
  18  
  19  const bridge = {
  20    feed_worker_on_message(cbID) { _workerMsgCBID = cbID; },
  21    feed_worker_post(ptr, len) { self.postMessage(readStr(ptr, len)); },
  22    feed_worker_set_timeout(ms, cbID) { return setTimeout(() => cb0(cbID), ms); },
  23    feed_worker_clear_timeout(h) { clearTimeout(h); },
  24    feed_worker_now_seconds() { return BigInt(Math.floor(Date.now() / 1000)); },
  25    feed_send(ptr, len) { self.postMessage({ type: 'feed-send', msg: readStr(ptr, len) }); },
  26    feed_on_message(cbID) { _consumerMsgCBID = cbID; },
  27    ...makeCommonBridge(h, _sabTable, _sabSeqRef, _wasmUrlRef, _buildHashRef, _spawnedWorkerChans),
  28  };
  29  
  30  const wasi = makeWasi(() => mem);
  31  
  32  self.addEventListener('unhandledrejection', function(ev) {
  33    self.postMessage('["__WASM_FATAL","unhandledrejection: ' + jsonEsc(String(ev.reason)) + '"]');
  34  });
  35  
  36  self.onmessage = async function(e) {
  37    const d = e.data;
  38    if (d && d.type === 'init' && d.mode === 'root') {
  39      try {
  40        const wasmBytes = await fetch(d.wasmUrl, { cache: 'no-store' }).then(r => r.arrayBuffer());
  41        _wasmUrlRef.value = d.wasmUrl;
  42        _buildHashRef.value = await computeBuildHash(wasmBytes);
  43        const { instance } = await WebAssembly.instantiate(wasmBytes, { bridge, wasi_snapshot_preview1: wasi });
  44        mem = instance.exports.memory; xp = instance.exports;
  45        xp._start();
  46        while (_pending.length > 0) {
  47          const m = _pending.shift();
  48          if (typeof m === 'string' && _workerMsgCBID) cbs(_workerMsgCBID, m);
  49          else if (m && m.type === '__feed_msg' && _consumerMsgCBID) cbs(_consumerMsgCBID, m.msg || '');
  50        }
  51        self.postMessage('["__WASM_BOOTED"]');
  52      } catch (err) {
  53        self.postMessage('["__WASM_FATAL","boot: ' + jsonEsc(String(err)) + '"]');
  54      }
  55      return;
  56    }
  57    if (_workerMsgCBID || _consumerMsgCBID) {
  58      if (typeof d === 'string' && _workerMsgCBID) cbs(_workerMsgCBID, d);
  59      if (d && d.type === '__feed_msg' && _consumerMsgCBID) cbs(_consumerMsgCBID, d.msg || '');
  60    } else {
  61      _pending.push(d);
  62    }
  63  };
  64