feat: initializeSwingset snapshots XS supervisor

  - add snapstore to SwingStore API

packages/SwingSet/src/controller.js

@@ -395,9 +395,7 @@ export async function makeSwingsetController(
  *   debugPrefix?: string,
  *   slogCallbacks?: unknown,
  *   testTrackDecref?: unknown,
- *   snapstorePath?: string,
  * }} runtimeOptions
- * @typedef { import('@agoric/swing-store-simple').SwingStore } SwingStore
  */
 export async function buildVatController(
   config,
@@ -411,14 +409,12 @@ export async function buildVatController(
     debugPrefix,
     slogCallbacks,
     testTrackDecref,
-    snapstorePath,
   } = runtimeOptions;
   const actualRuntimeOptions = {
     verbose,
     debugPrefix,
     testTrackDecref,
     slogCallbacks,
-    snapstorePath,
   };
   const initializationOptions = { verbose, kernelBundles };
   let bootstrapResult;

packages/SwingSet/src/initializeSwingset.js

@@ -2,11 +2,14 @@
 // @ts-check
 import fs from 'fs';
 import path from 'path';
+import { spawn } from 'child_process';
+import { type as osType } from 'os';
 
 import { assert, details as X } from '@agoric/assert';
 import bundleSource from '@agoric/bundle-source';
 import { initSwingStore } from '@agoric/swing-store-simple';
 
+import { xsnap } from '@agoric/xsnap';
 import { insistStorageAPI } from './storageAPI';
 import { initializeKernel } from './kernel/initializeKernel';
 
@@ -214,6 +217,26 @@ export function swingsetIsInitialized(storage) {
   return !!storage.get('initialized');
 }
 
+/**
+ * @param {Record<string, BundleGE>} bundles
+ * @param {ReturnType<typeof import('@agoric/xsnap').makeSnapstore>} snapstore
+ * @param {boolean} debug
+ * @typedef { any } BundleGE TODO: types for bundleSource
+ * @returns { Promise<string> } hash of supervisor snapshot
+ */
+async function snapshotSupervisor(bundles, snapstore, debug) {
+  const worker = xsnap({
+    handleCommand: async bytes => bytes,
+    spawn,
+    os: osType(),
+    debug,
+  });
+  await worker.evaluate(`(${bundles.lockdown.source}\n)()`);
+  await worker.evaluate(`(${bundles.supervisor.source}\n)()`);
+  const supervisorHash = await snapstore.save(async fn => worker.snapshot(fn));
+  return supervisorHash;
+}
+
 /**
  * @param {SwingSetConfig} config
  * @param {string[]} argv
@@ -248,7 +271,9 @@ export async function initializeSwingset(
   }
 
   // Use ambient process.env only if caller did not specify.
-  const { env: { SWINGSET_WORKER_TYPE } = process.env } = runtimeOptions;
+  const {
+    env: { SWINGSET_WORKER_TYPE, XSNAP_DEBUG } = process.env,
+  } = runtimeOptions;
   const defaultManagerType = config.defaultManagerType || SWINGSET_WORKER_TYPE;
   switch (defaultManagerType) {
     case 'local':
@@ -270,6 +295,15 @@ export async function initializeSwingset(
   hostStorage.set('lockdownBundle', JSON.stringify(kernelBundles.lockdown));
   hostStorage.set('supervisorBundle', JSON.stringify(kernelBundles.supervisor));
 
+  if (hostStorage.snapstore) {
+    const supervisorHash = await snapshotSupervisor(
+      kernelBundles,
+      hostStorage.snapstore,
+      !!XSNAP_DEBUG,
+    );
+    hostStorage.set('supervisorHash', JSON.stringify(supervisorHash));
+  }
+
   if (config.bootstrap && argv) {
     const bootConfig = config.vats[config.bootstrap];
     if (bootConfig) {

packages/SwingSet/src/types.js

@@ -90,3 +90,9 @@
  *
  * Swingsets defined by scanning a directory in this manner define no devices.
  */
+
+/**
+ * @typedef { import('@agoric/swing-store-simple').SwingStore & {
+ *   snapstore?: ReturnType<typeof import('@agoric/xsnap').makeSnapstore>
+ * }} SwingStore
+ */

packages/SwingSet/test/test-controller.js

@@ -3,7 +3,10 @@
 import { test } from '../tools/prepare-test-env-ava';
 
 import path from 'path';
+import fs from 'fs';
+import { tmpName } from 'tmp';
 import { initSwingStore } from '@agoric/swing-store-simple';
+import { makeSnapstore } from '@agoric/xsnap';
 import { buildVatController, loadBasedir } from '../src/index';
 import { checkKT } from './util';
 
@@ -117,6 +120,28 @@ test('XS bootstrap', async t => {
   );
 });
 
+test('SwingStore with snapstore', async t => {
+  const snapstorePath = path.resolve(__dirname, './fixture-xs-snapshots/');
+  fs.mkdirSync(snapstorePath, { recursive: true });
+
+  const kvStorage = initSwingStore().storage;
+
+  const snapstore = makeSnapstore(snapstorePath, {
+    tmpName,
+    existsSync: fs.existsSync,
+    createReadStream: fs.createReadStream,
+    createWriteStream: fs.createWriteStream,
+    rename: fs.promises.rename,
+    unlink: fs.promises.unlink,
+    resolve: path.resolve,
+  });
+  const hostStorage = { snapstore, ...kvStorage };
+  await buildVatController({}, [], { hostStorage });
+  const supervisorHash = hostStorage.get('supervisorHash');
+  t.is(typeof supervisorHash, 'string', 'supervisorHash is available');
+  t.is(supervisorHash.length, 66, 'supervisorHash is available');
+});
+
 test('validate config.defaultManagerType', async t => {
   const config = await loadBasedir(
     path.resolve(__dirname, 'basedir-controller-2'),

packages/cosmic-swingset/lib/ag-solo/start.js

@@ -2,6 +2,7 @@
 import fs from 'fs';
 import path from 'path';
 import temp from 'temp';
+import { tmpName } from 'tmp'; // TODO: reconcile tmp vs. temp
 import { fork } from 'child_process';
 import { promisify } from 'util';
 // import { createHash } from 'crypto';
@@ -24,6 +25,7 @@ import {
   buildPlugin,
   buildTimer,
 } from '@agoric/swingset-vat';
+import { makeSnapstore } from '@agoric/xsnap';
 import { getBestSwingStore } from '../check-lmdb';
 
 import { deliver, addDeliveryTarget } from './outbound';
@@ -141,7 +143,20 @@ async function buildSwingset(
 
   const tempdir = path.resolve(kernelStateDBDir, 'check-lmdb-tempdir');
   const { openSwingStore } = getBestSwingStore(tempdir);
-  const { storage, commit } = openSwingStore(kernelStateDBDir);
+  const { storage: storage0, commit } = openSwingStore(kernelStateDBDir);
+  const snapstore = makeSnapstore(
+    path.resolve(kernelStateDBDir, 'xs-snapshots'),
+    {
+      tmpName,
+      existsSync: fs.existsSync,
+      createReadStream: fs.createReadStream,
+      createWriteStream: fs.createWriteStream,
+      rename: fs.promises.rename,
+      unlink: fs.promises.unlink,
+      resolve: path.resolve,
+    },
+  );
+  const storage = { snapstore, ...storage0 };
 
   if (!swingsetIsInitialized(storage)) {
     if (defaultManagerType && !config.defaultManagerType) {