feat: implement swingStore data export/import in support of state sync

Closes #6773

packages/SwingSet/misc-tools/extract-transcript-from-kerneldb.js

@@ -18,7 +18,7 @@ if (!dirPath) {
 if (!isSwingStore(dirPath)) {
   throw Error(`${dirPath} does not appear to be a swingstore (no ./data.mdb)`);
 }
-const { kvStore, streamStore } = openSwingStore(dirPath).kernelStorage;
+const { kvStore, transcriptStore } = openSwingStore(dirPath).kernelStorage;
 function get(key) {
   return kvStore.get(key);
 }
@@ -98,7 +98,7 @@ if (!vatName) {
   fs.writeSync(fd, JSON.stringify(first));
   fs.writeSync(fd, '\n');
 
-  // The streamStore holds concatenated transcripts from all upgraded
+  // The transcriptStore holds concatenated transcripts from all upgraded
   // versions. For each old version, it holds every delivery from
   // `startVat` through `stopVat`. For the current version, it holds
   // every delivery from `startVat` up through the last delivery
@@ -123,9 +123,8 @@ if (!vatName) {
   console.log(`${transcriptLength} transcript entries`);
 
   let deliveryNum = 0;
-  const transcriptStream = `transcript-${vatID}`;
-  const stream = streamStore.readStream(transcriptStream, startPos, endPos);
-  for (const entry of stream) {
+  const transcript = transcriptStore.readSpan(vatID, startPos, endPos);
+  for (const entry of transcript) {
     // entry is JSON.stringify({ d, syscalls }), syscall is { d, response }
     const t = { transcriptNum, ...JSON.parse(entry) };
     // console.log(`t.${deliveryNum} : ${t}`);

packages/SwingSet/misc-tools/replay-transcript.js

@@ -142,7 +142,7 @@ async function replay(transcriptFile) {
           return loadRaw(snapFile);
         },
       }
-    : makeSnapStore(process.cwd(), makeSnapStoreIO());
+    : makeSnapStore(process.cwd(), () => {}, makeSnapStoreIO());
   const testLog = undefined;
   const meterControl = makeDummyMeterControl();
   const gcTools = harden({

packages/SwingSet/src/kernel/state/kernelKeeper.js

@@ -38,8 +38,7 @@ const enableKernelGC = true;
  * @typedef { import('../../types-external.js').KernelSlog } KernelSlog
  * @typedef { import('../../types-external.js').ManagerType } ManagerType
  * @typedef { import('../../types-external.js').SnapStore } SnapStore
- * @typedef { import('../../types-external.js').StreamPosition } StreamPosition
- * @typedef { import('../../types-external.js').StreamStore } StreamStore
+ * @typedef { import('../../types-external.js').TranscriptStore } TranscriptStore
  * @typedef { import('../../types-external.js').VatKeeper } VatKeeper
  * @typedef { import('../../types-external.js').VatManager } VatManager
  */
@@ -86,8 +85,6 @@ const enableKernelGC = true;
 //   $vatSlot is one of: o+$NN/o-$NN/p+$NN/p-$NN/d+$NN/d-$NN
 // v$NN.c.$vatSlot = $kernelSlot = ko$NN/kp$NN/kd$NN
 // v$NN.nextDeliveryNum = $NN
-// v$NN.t.startPosition = $NN // inclusive
-// v$NN.t.endPosition = $NN  // exclusive
 // v$NN.vs.$key = string
 // v$NN.meter = m$NN // XXX does this exist?
 // v$NN.reapInterval = $NN or 'never'
@@ -174,7 +171,7 @@ const FIRST_METER_ID = 1n;
  * @param {KernelSlog|null} kernelSlog
  */
 export default function makeKernelKeeper(kernelStorage, kernelSlog) {
-  const { kvStore, streamStore, snapStore } = kernelStorage;
+  const { kvStore, transcriptStore, snapStore } = kernelStorage;
 
   insistStorageAPI(kvStore);
 
@@ -787,7 +784,7 @@ export default function makeKernelKeeper(kernelStorage, kernelSlog) {
     const promisePrefix = `${vatID}.c.p`;
     const kernelPromisesToReject = [];
 
-    vatKeeper.deleteSnapshots();
+    vatKeeper.deleteSnapshotsAndTranscript();
 
     // Note: ASCII order is "+,-./", and we rely upon this to split the
     // keyspace into the various o+NN/o-NN/etc spaces. If we were using a
@@ -1297,11 +1294,11 @@ export default function makeKernelKeeper(kernelStorage, kernelSlog) {
       return found;
     }
     if (!kvStore.has(`${vatID}.o.nextID`)) {
-      initializeVatState(kvStore, streamStore, vatID);
+      initializeVatState(kvStore, transcriptStore, vatID);
     }
     const vk = makeVatKeeper(
       kvStore,
-      streamStore,
+      transcriptStore,
       kernelSlog,
       vatID,
       addKernelObject,
@@ -1328,20 +1325,6 @@ export default function makeKernelKeeper(kernelStorage, kernelSlog) {
   }
 
   /**
-   * Cease writing to the vat's transcript.
-   *
-   * @param {string} vatID
-   */
-  function closeVatTranscript(vatID) {
-    insistVatID(vatID);
-    const transcriptStream = `transcript-${vatID}`;
-    streamStore.closeStream(transcriptStream);
-  }
-
-  /**
-   * NOTE: caller is responsible to closeVatTranscript()
-   * before evicting a VatKeeper.
-   *
    * @param {string} vatID
    */
   function evictVatKeeper(vatID) {
@@ -1448,7 +1431,6 @@ export default function makeKernelKeeper(kernelStorage, kernelSlog) {
       if (vk) {
         // TODO: find some way to expose the liveSlots internal tables, the
         // kernel doesn't see them
-        closeVatTranscript(vatID);
         const vatTable = {
           vatID,
           state: { transcript: Array.from(vk.getTranscript()) },
@@ -1615,7 +1597,6 @@ export default function makeKernelKeeper(kernelStorage, kernelSlog) {
     provideVatKeeper,
     vatIsAlive,
     evictVatKeeper,
-    closeVatTranscript,
     cleanupAfterTerminatedVat,
     addDynamicVatID,
     getDynamicVats,

packages/SwingSet/src/kernel/state/vatKeeper.js

@@ -18,8 +18,7 @@ import { enumeratePrefixedKeys } from './storageHelper.js';
  * @typedef { import('../../types-external.js').ManagerOptions } ManagerOptions
  * @typedef { import('../../types-external.js').SnapStore } SnapStore
  * @typedef { import('../../types-external.js').SourceOfBundle } SourceOfBundle
- * @typedef { import('../../types-external.js').StreamPosition } StreamPosition
- * @typedef { import('../../types-external.js').StreamStore } StreamStore
+ * @typedef { import('../../types-external.js').TranscriptStore } TranscriptStore
  * @typedef { import('../../types-external.js').VatManager } VatManager
  * @typedef { import('../../types-internal.js').RecordedVatOptions } RecordedVatOptions
  * @typedef { import('../../types-external.js').TranscriptEntry } TranscriptEntry
@@ -36,25 +35,24 @@ const FIRST_DEVICE_ID = 70n;
  * Establish a vat's state.
  *
  * @param {*} kvStore  The key-value store in which the persistent state will be kept
- * @param {*} streamStore  Accompanying stream store
+ * @param {*} transcriptStore  Accompanying transcript store
  * @param {string} vatID The vat ID string of the vat in question
  * TODO: consider making this part of makeVatKeeper
  */
-export function initializeVatState(kvStore, streamStore, vatID) {
+export function initializeVatState(kvStore, transcriptStore, vatID) {
   kvStore.set(`${vatID}.o.nextID`, `${FIRST_OBJECT_ID}`);
   kvStore.set(`${vatID}.p.nextID`, `${FIRST_PROMISE_ID}`);
   kvStore.set(`${vatID}.d.nextID`, `${FIRST_DEVICE_ID}`);
   kvStore.set(`${vatID}.nextDeliveryNum`, `0`);
   kvStore.set(`${vatID}.incarnationNumber`, `1`);
-  kvStore.set(`${vatID}.t.startPosition`, `${streamStore.STREAM_START}`);
-  kvStore.set(`${vatID}.t.endPosition`, `${streamStore.STREAM_START}`);
+  transcriptStore.initTranscript(vatID);
 }
 
 /**
  * Produce a vat keeper for a vat.
  *
  * @param {KVStore} kvStore  The keyValue store in which the persistent state will be kept
- * @param {StreamStore} streamStore  Accompanying stream store, for the transcripts
+ * @param {TranscriptStore} transcriptStore  Accompanying transcript store, for the transcripts
  * @param {*} kernelSlog
  * @param {string} vatID  The vat ID string of the vat in question
  * @param {*} addKernelObject  Kernel function to add a new object to the kernel's
@@ -76,7 +74,7 @@ export function initializeVatState(kvStore, streamStore, vatID) {
  */
 export function makeVatKeeper(
   kvStore,
-  streamStore,
+  transcriptStore,
   kernelSlog,
   vatID,
   addKernelObject,
@@ -94,7 +92,6 @@ export function makeVatKeeper(
   snapStore = undefined,
 ) {
   insistVatID(vatID);
-  const transcriptStream = `transcript-${vatID}`;
 
   function getRequired(key) {
     const value = kvStore.get(key);
@@ -475,20 +472,12 @@ export function makeVatKeeper(
   /**
    * Generator function to return the vat's transcript, one entry at a time.
    *
-   * @param {StreamPosition} [startPos]  Optional position to begin reading from
+   * @param {number} [startPos]  Optional position to begin reading from
    *
    * @yields { TranscriptEntry } a stream of transcript entries
    */
   function* getTranscript(startPos) {
-    if (startPos === undefined) {
-      startPos = Number(getRequired(`${vatID}.t.startPosition`));
-    }
-    const endPos = Number(getRequired(`${vatID}.t.endPosition`));
-    for (const entry of streamStore.readStream(
-      transcriptStream,
-      /** @type { StreamPosition } */ (startPos),
-      endPos,
-    )) {
+    for (const entry of transcriptStore.readSpan(vatID, startPos)) {
       yield /** @type { TranscriptEntry } */ (JSON.parse(entry));
     }
   }
@@ -499,21 +488,13 @@ export function makeVatKeeper(
    * @param {object} entry  The transcript entry to append.
    */
   function addToTranscript(entry) {
-    const oldPos = Number(getRequired(`${vatID}.t.endPosition`));
-    const newPos = streamStore.writeStreamItem(
-      transcriptStream,
-      JSON.stringify(entry),
-      oldPos,
-    );
-    kvStore.set(`${vatID}.t.endPosition`, `${newPos}`);
+    transcriptStore.addItem(vatID, JSON.stringify(entry));
   }
 
-  /** @returns {StreamPosition} */
+  /** @returns {number} */
   function getTranscriptEndPosition() {
-    const endPosition =
-      kvStore.get(`${vatID}.t.endPosition`) ||
-      assert.fail('missing endPosition');
-    return Number(endPosition);
+    const { endPos } = transcriptStore.getCurrentSpanBounds(vatID);
+    return endPos;
   }
 
   function getSnapshotInfo() {
@@ -540,6 +521,7 @@ export function makeVatKeeper(
 
     const endPosition = getTranscriptEndPosition();
     const info = await manager.makeSnapshot(endPosition, snapStore);
+    transcriptStore.rolloverSpan(vatID);
     const {
       hash,
       uncompressedSize,
@@ -560,19 +542,18 @@ export function makeVatKeeper(
     return true;
   }
 
-  function deleteSnapshots() {
+  function deleteSnapshotsAndTranscript() {
     if (snapStore) {
       snapStore.deleteVatSnapshots(vatID);
     }
+    transcriptStore.deleteVatTranscripts(vatID);
   }
 
-  function removeSnapshotAndTranscript() {
+  function dropSnapshotAndResetTranscript() {
     if (snapStore) {
-      snapStore.deleteVatSnapshots(vatID);
+      snapStore.stopUsingLastSnapshot(vatID);
     }
-
-    const endPos = getRequired(`${vatID}.t.endPosition`);
-    kvStore.set(`${vatID}.t.startPosition`, endPos);
+    transcriptStore.rolloverSpan(vatID);
   }
 
   function vatStats() {
@@ -584,9 +565,8 @@ export function makeVatKeeper(
     const objectCount = getCount(`${vatID}.o.nextID`, FIRST_OBJECT_ID);
     const promiseCount = getCount(`${vatID}.p.nextID`, FIRST_PROMISE_ID);
     const deviceCount = getCount(`${vatID}.d.nextID`, FIRST_DEVICE_ID);
-    const startCount = Number(getRequired(`${vatID}.t.startPosition`));
-    const endCount = Number(getRequired(`${vatID}.t.endPosition`));
-    const transcriptCount = endCount - startCount;
+    const { startPos, endPos } = transcriptStore.getCurrentSpanBounds(vatID);
+    const transcriptCount = endPos - startPos;
 
     // TODO: Fix the downstream JSON.stringify to allow the counts to be BigInts
     return harden({
@@ -645,8 +625,8 @@ export function makeVatKeeper(
     vatStats,
     dumpState,
     saveSnapshot,
-    deleteSnapshots,
     getSnapshotInfo,
-    removeSnapshotAndTranscript,
+    deleteSnapshotsAndTranscript,
+    dropSnapshotAndResetTranscript,
   });
 }

packages/SwingSet/src/kernel/vat-warehouse.js

@@ -241,7 +241,6 @@ export function makeVatWarehouse(kernelKeeper, vatLoader, policyOptions) {
     }
     ephemeral.vats.delete(vatID);
     xlate.delete(vatID);
-    kernelKeeper.closeVatTranscript(vatID);
     kernelKeeper.evictVatKeeper(vatID);
 
     // console.log('evict: shutting down', vatID);
@@ -383,7 +382,7 @@ export function makeVatWarehouse(kernelKeeper, vatLoader, policyOptions) {
   async function resetWorker(vatID) {
     await evict(vatID);
     const vatKeeper = kernelKeeper.provideVatKeeper(vatID);
-    vatKeeper.removeSnapshotAndTranscript();
+    vatKeeper.dropSnapshotAndResetTranscript();
   }
 
   /**

packages/SwingSet/src/types-ambient.js

@@ -135,8 +135,7 @@
  */
 /**
  * @typedef { import('@agoric/swing-store').KVStore } KVStore
- * @typedef { import('@agoric/swing-store').StreamStore } StreamStore
- * @typedef { import('@agoric/swing-store').StreamPosition } StreamPosition
+ * @typedef { import('@agoric/swing-store').TranscriptStore } TranscriptStore
  * @typedef { import('@agoric/swing-store').SwingStore } SwingStore
  * @typedef { import('@agoric/swing-store').SwingStoreKernelStorage } SwingStoreKernelStorage
  * @typedef { import('@agoric/swing-store').SwingStoreHostStorage } SwingStoreHostStorage

packages/SwingSet/src/types-external.js

@@ -205,7 +205,7 @@ export {};
  *                                 vatSyscallHandler: unknown) => Promise<VatManager>,
  *            } } VatManagerFactory
  * @typedef { { deliver: (delivery: VatDeliveryObject) => Promise<VatDeliveryResult>,
- *              replayTranscript: (startPos: StreamPosition | undefined) => Promise<number?>,
+ *              replayTranscript: (startPos: number | undefined) => Promise<number?>,
  *              makeSnapshot?: (endPos: number, ss: SnapStore) => Promise<SnapshotResult>,
  *              shutdown: () => Promise<void>,
  *            } } VatManager
@@ -273,8 +273,7 @@ export {};
  * @typedef { import('@agoric/swing-store').KVStore } KVStore
  * @typedef { import('@agoric/swing-store').SnapStore } SnapStore
  * @typedef { import('@agoric/swing-store').SnapshotResult } SnapshotResult
- * @typedef { import('@agoric/swing-store').StreamStore } StreamStore
- * @typedef { import('@agoric/swing-store').StreamPosition } StreamPosition
+ * @typedef { import('@agoric/swing-store').TranscriptStore } TranscriptStore
  * @typedef { import('@agoric/swing-store').SwingStore } SwingStore
  * @typedef { import('@agoric/swing-store').SwingStoreKernelStorage } SwingStoreKernelStorage
  * @typedef { import('@agoric/swing-store').SwingStoreHostStorage } SwingStoreHostStorage

packages/SwingSet/test/device-plugin/test-device.js

@@ -90,6 +90,12 @@ test.serial('plugin first time', async t => {
   ]);
 });
 
+// NOTE: the following test CANNOT be run standalone. It requires execution of
+// the prior test to establish its necessary starting state.  This is a bad
+// practice and should be fixed.  It's not bad enough to warrant fixing right
+// now, but worth flagging with this comment as a help to anyone else who gets
+// tripped up by it.
+
 test.serial('plugin after restart', async t => {
   const { bridge, cycle, dump, plugin, queueThunkForKernel } =
     await setupVatController(t);

packages/SwingSet/test/test-state.js

@@ -145,13 +145,15 @@ function duplicateKeeper(serialize) {
 
 test('kernelStorage param guards', async t => {
   const { kvStore } = buildKeeperStorageInMemory();
-  const exp = { message: /true must be a string/ };
-  t.throws(() => kvStore.set('foo', true), exp);
-  t.throws(() => kvStore.set(true, 'foo'), exp);
-  t.throws(() => kvStore.has(true), exp);
-  t.throws(() => kvStore.getNextKey(true), exp);
-  t.throws(() => kvStore.get(true), exp);
-  t.throws(() => kvStore.delete(true), exp);
+  const expv = { message: /value must be a string/ };
+  const expk = { message: /key must be a string/ };
+  const exppk = { message: /previousKey must be a string/ };
+  t.throws(() => kvStore.set('foo', true), expv);
+  t.throws(() => kvStore.set(true, 'foo'), expk);
+  t.throws(() => kvStore.has(true), expk);
+  t.throws(() => kvStore.getNextKey(true), exppk);
+  t.throws(() => kvStore.get(true), expk);
+  t.throws(() => kvStore.delete(true), expk);
 });
 
 test('kernel state', async t => {

packages/SwingSet/test/test-xsnap-metering.js

@@ -45,7 +45,7 @@ function checkMetered(t, args, metered) {
 
 async function doTest(t, metered) {
   const db = sqlite3(':memory:');
-  const store = makeSnapStore(db, makeSnapStoreIO());
+  const store = makeSnapStore(db, () => {}, makeSnapStoreIO());
 
   const { p: p1, startXSnap: start1 } = make(store);
   const worker1 = await start1('vat', 'name', handleCommand, metered, false);