mls-wasm-host.mjs raw

   1  // mls-wasm-host.mjs — Worker bootstrap for mls.wasm.
   2  import {
   3    makeCoreHelpers, makeWasi, makeEnv, 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;
  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    mlsw_worker_on_message(cbID) { _workerMsgCBID = cbID; },
  21    mlsw_worker_post(ptr, len) { self.postMessage(readStr(ptr, len)); },
  22    mlsw_worker_set_timeout(ms, cbID) { return setTimeout(() => cb0(cbID), ms); },
  23    mlsw_worker_clear_timeout(h) { clearTimeout(h); },
  24    mlsw_worker_now_seconds() { return BigInt(Math.floor(Date.now() / 1000)); },
  25    ...makeCommonBridge(h, _sabTable, _sabSeqRef, _wasmUrlRef, _buildHashRef, _spawnedWorkerChans),
  26  };
  27  
  28  const wasi = makeWasi(() => mem);
  29  const env = makeEnv(() => mem);
  30  
  31  self.addEventListener('unhandledrejection', function(ev) {
  32    self.postMessage('["__WASM_FATAL","unhandledrejection: ' + jsonEsc(String(ev.reason)) + '"]');
  33  });
  34  
  35  self.onmessage = async function(e) {
  36    const d = e.data;
  37    if (d && d.type === 'init' && d.mode === 'root') {
  38      try {
  39        const wasmBytes = await fetch(d.wasmUrl, { cache: 'no-store' }).then(r => r.arrayBuffer());
  40        _wasmUrlRef.value = d.wasmUrl;
  41        _buildHashRef.value = await computeBuildHash(wasmBytes);
  42        const { instance } = await WebAssembly.instantiate(wasmBytes, { bridge, env, wasi_snapshot_preview1: wasi });
  43        mem = instance.exports.memory; xp = instance.exports;
  44        xp._start();
  45        while (_pending.length > 0) {
  46          const m = _pending.shift();
  47          if (typeof m === 'string' && _workerMsgCBID) cbs(_workerMsgCBID, m);
  48        }
  49        self.postMessage('["__WASM_BOOTED"]');
  50      } catch (err) {
  51        self.postMessage('["__WASM_FATAL","boot: ' + jsonEsc(String(err)) + '"]');
  52      }
  53      return;
  54    }
  55    if (_workerMsgCBID) {
  56      if (typeof d === 'string') cbs(_workerMsgCBID, d);
  57    } else {
  58      _pending.push(d);
  59    }
  60  };
  61