fix: Preserve smart wallets through bulldozer upgrade

golang/cosmos/x/vstorage/vstorage.go

@@ -197,7 +197,11 @@ func (sh vstorageHandler) Receive(cctx *vm.ControllerContext, str string) (ret s
 		entries := make([][]interface{}, len(children.Children))
 		for i, child := range children.Children {
 			entry := keeper.GetEntry(cctx.Context, fmt.Sprintf("%s.%s", path, child))
-			entries[i] = []interface{}{child, entry.Value()}
+			if !entry.HasData() {
+				entries[i] = []interface{}{child}
+			} else {
+				entries[i] = []interface{}{child, entry.Value()}
+			}
 		}
 		bytes, err := json.Marshal(entries)
 		if err != nil {

golang/cosmos/x/vstorage/vstorage_test.go

@@ -110,7 +110,7 @@ func TestGetAndHas(t *testing.T) {
 				t.Errorf("%s: got unexpected error %v", desc.label, err)
 			}
 
-			// Verify that has returns false iff get returns null.
+			// Verify that `has` returns false iff `get` returns null.
 			noData := desc.want == `null`
 			if (noData && has != `false`) || (!noData && has != `true`) {
 				t.Errorf("%s: got has %v; want %v", desc.label, has, !noData)
@@ -274,13 +274,13 @@ func TestEntries(t *testing.T) {
 		want string
 	}
 	cases := []testCase{
-		{path: "key1", want: `[["child1",null]]`},
+		{path: "key1", want: `[["child1"]]`},
 		{path: "key1.child1",
 			// Empty non-terminals are included, empty leaves are not.
-			want: `[["empty-non-terminal",null],["grandchild1","value1grandchild"]]`},
+			want: `[["empty-non-terminal"],["grandchild1","value1grandchild"]]`},
 		{path: "key1.child1.grandchild1", want: `[]`},
 		{path: "key1.child1.empty-non-terminal", want: `[["leaf",""]]`},
-		{path: "key2", want: `[["child2",null]]`},
+		{path: "key2", want: `[["child2"]]`},
 		{path: "key2.child2",
 			want: `[["grandchild2","value2grandchild"],["grandchild2a","value2grandchilda"]]`},
 		{path: "nosuchkey", want: `[]`},

packages/SwingSet/src/types-external.js

@@ -180,7 +180,7 @@ export {};
  * @property {string[]} [exportStorageSubtrees] chain storage paths identifying roots of subtrees
  *   for which data should be exported into bootstrap vat parameter `chainStorageEntries`
  *   (e.g., `exportStorageSubtrees: ['c.o']` might result in vatParameters including
- *   `chainStorageEntries: [ ['c.o', null], ['c.o.i', null], ['c.o.i.n', '42'], ['c.o.w', '"moo"'] ]`).
+ *   `chainStorageEntries: [ ['c.o', '"top"'], ['c.o.i'], ['c.o.i.n', '42'], ['c.o.w', '"moo"'] ]`).
  * @property {boolean} [includeDevDependencies] indicates that
  * `devDependencies` of the surrounding `package.json` should be accessible to
  * bundles.

packages/casting/package.json

@@ -22,6 +22,7 @@
   "author": "Agoric",
   "license": "Apache-2.0",
   "dependencies": {
+    "@agoric/internal": "^0.2.1",
     "@agoric/notifier": "^0.5.1",
     "@agoric/spawner": "^0.6.3",
     "@agoric/store": "^0.8.3",

packages/casting/src/follower-cosmjs.js

@@ -5,6 +5,8 @@ import { E, Far } from '@endo/far';
 import * as tendermint34 from '@cosmjs/tendermint-rpc';
 import * as stargateStar from '@cosmjs/stargate';
 
+import { isStreamCell } from '@agoric/internal/src/lib-chainStorage.js';
+
 import { MAKE_DEFAULT_DECODER, MAKE_DEFAULT_UNSERIALIZER } from './defaults.js';
 import { makeCastingSpec } from './casting-spec.js';
 import { makeLeader as defaultMakeLeader } from './leader-netconfig.js';
@@ -27,21 +29,6 @@ const textDecoder = new TextDecoder();
  * to abstract away Tendermint versions.
  */
 
-/**
- * This is an imperfect heuristic to navigate the migration from value cells to
- * stream cells.
- * At time of writing, no legacy cells have the same shape as a stream cell,
- * and we do not intend to create any more legacy value cells.
- *
- * @param {any} cell
- */
-const isStreamCell = cell =>
-  cell &&
-  typeof cell === 'object' &&
-  Array.isArray(cell.values) &&
-  typeof cell.blockHeight === 'string' &&
-  /^0$|^[1-9][0-9]*$/.test(cell.blockHeight);
-
 /**
  * @param {Uint8Array} a
  * @param {Uint8Array} b

packages/cosmic-swingset/src/launch-chain.js

@@ -124,7 +124,7 @@ export async function buildSwingset(
       bootVat.parameters = { ...bootVat.parameters, coreProposalCode: code };
     }
 
-    // Extract data from chain storage.
+    // Extract data from chain storage as [path, value?] pairs.
     if (exportStorageSubtrees) {
       // Disallow exporting internal details like bundle contents and the action queue.
       const exportRoot = STORAGE_PATH.CUSTOM;
@@ -137,19 +137,22 @@ export async function buildSwingset(
 
       const callChainStorage = (method, path) =>
         bridgeOutbound(BRIDGE_ID.STORAGE, { method, args: [path] });
+      const makeExportEntry = (path, value) =>
+        value == null ? [path] : [path, value];
+
       const chainStorageEntries = [];
       // Preserve the ordering of each subtree via depth-first traversal.
       let pendingEntries = exportStorageSubtrees.map(path => {
         const value = callChainStorage('get', path);
-        return [path, value];
+        return makeExportEntry(path, value);
       });
       while (pendingEntries.length > 0) {
-        const entry = /** @type {[string, string]} */ (pendingEntries.shift());
+        const entry = /** @type {[string, string?]} */ (pendingEntries.shift());
         chainStorageEntries.push(entry);
         const [path, _value] = entry;
         const childEntryData = callChainStorage('entries', path);
         const childEntries = childEntryData.map(([pathSegment, value]) => {
-          return [`${path}.${pathSegment}`, value];
+          return makeExportEntry(`${path}.${pathSegment}`, value);
         });
         pendingEntries = [...childEntries, ...pendingEntries];
       }

packages/inter-protocol/src/proposals/startPSM.js

@@ -7,7 +7,11 @@ import { makeStorageNodeChild } from '@agoric/internal/src/lib-chainStorage.js';
 import { makeRatio } from '@agoric/zoe/src/contractSupport/index.js';
 import { E } from '@endo/far';
 import { Stable } from '@agoric/vats/src/tokens.js';
-import { makeHistoryReviver } from '@agoric/vats/tools/board-utils.js';
+import {
+  makeHistoryReviver,
+  makeBoardRemote,
+  slotToBoardRemote,
+} from '@agoric/vats/tools/board-utils.js';
 import { deeplyFulfilledObject } from '@agoric/internal';
 import { makeScalarBigMapStore } from '@agoric/vat-data';
 
@@ -39,20 +43,30 @@ const stablePsmKey = `published.psm.${Stable.symbol}`;
 const findOldPSMState = (chainStorageEntries, keyword, brands) => {
   // In this reviver, object references are revived as boardIDs
   // from the pre-bulldozer board.
-  const toSlotReviver = makeHistoryReviver(chainStorageEntries);
+  const toSlotReviver = makeHistoryReviver(
+    chainStorageEntries,
+    slotToBoardRemote,
+  );
   if (!toSlotReviver.has(`${stablePsmKey}.${keyword}.metrics`)) {
     return {};
   }
   const metricsWithOldBoardIDs = toSlotReviver.getItem(
     `${stablePsmKey}.${keyword}.metrics`,
   );
   const oldIDtoNewBrand = makeMap([
-    [metricsWithOldBoardIDs.feePoolBalance.brand, brands.minted],
-    [metricsWithOldBoardIDs.anchorPoolBalance.brand, brands.anchor],
+    [metricsWithOldBoardIDs.feePoolBalance.brand.getBoardId(), brands.minted],
+    [
+      metricsWithOldBoardIDs.anchorPoolBalance.brand.getBoardId(),
+      brands.anchor,
+    ],
   ]);
-  // revive brands; other object references map to undefined
-  const brandReviver = makeHistoryReviver(chainStorageEntries, s =>
-    oldIDtoNewBrand.get(s),
+  // revive brands; other object references map to dummy remotables
+  const brandReviver = makeHistoryReviver(
+    chainStorageEntries,
+    (slotID, iface) => {
+      const newBrand = oldIDtoNewBrand.get(slotID);
+      return newBrand || makeBoardRemote({ boardId: slotID, iface });
+    },
   );
   return {
     metrics: brandReviver.getItem(`${stablePsmKey}.${keyword}.metrics`),
@@ -340,7 +354,10 @@ export const makeAnchorAsset = async (
 
   testFirstAnchorKit.resolve(kit);
 
-  const toSlotReviver = makeHistoryReviver(chainStorageEntries);
+  const toSlotReviver = makeHistoryReviver(
+    chainStorageEntries,
+    slotToBoardRemote,
+  );
   const metricsKey = `${stablePsmKey}.${keyword}.metrics`;
   if (toSlotReviver.has(metricsKey)) {
     const metrics = toSlotReviver.getItem(metricsKey);
@@ -351,6 +368,8 @@ export const makeAnchorAsset = async (
     // eslint-disable-next-line @jessie.js/no-nested-await
     const anchorPaymentMap = await anchorBalancePayments;
 
+    // TODO: validate that `metrics.anchorPoolBalance.value` is
+    // pass-by-copy PureData (e.g., contains no remotables).
     // eslint-disable-next-line @jessie.js/no-nested-await
     const pmt = await E(mint).mintPayment(
       AmountMath.make(brand, metrics.anchorPoolBalance.value),

packages/internal/src/lib-chainStorage.js

@@ -19,6 +19,13 @@ const { Fail } = assert;
  * @property {string} [noDataValue]
  */
 
+/**
+ * @template [T=unknown]
+ * @typedef StreamCell
+ * @property {string} blockHeight decimal representation of a natural number
+ * @property {T[]} values
+ */
+
 /**
  * This represents a node in an IAVL tree.
  *
@@ -44,6 +51,70 @@ const ChainStorageNodeI = M.interface('StorageNode', {
     .returns(M.remotable('StorageNode')),
 });
 
+/**
+ * This is an imperfect heuristic to navigate the migration from value cells to
+ * stream cells.
+ * At time of writing, no legacy cells have the same shape as a stream cell,
+ * and we do not intend to create any more legacy value cells.
+ *
+ * @param {any} cell
+ * @returns {cell is StreamCell}
+ */
+export const isStreamCell = cell =>
+  cell &&
+  typeof cell === 'object' &&
+  Array.isArray(cell.values) &&
+  typeof cell.blockHeight === 'string' &&
+  /^0$|^[1-9][0-9]*$/.test(cell.blockHeight);
+harden(isStreamCell);
+
+// TODO: Consolidate with `insistCapData` functions from swingset-liveslots,
+// swingset-xsnap-supervisor, etc.
+/**
+ * @param {unknown} data
+ * @returns {asserts data is import('@endo/marshal').CapData<string>}
+ */
+export const assertCapData = data => {
+  assert.typeof(data, 'object');
+  assert(data);
+  assert.typeof(data.body, 'string');
+  assert(Array.isArray(data.slots));
+  // XXX check that the .slots array elements are actually strings
+};
+harden(assertCapData);
+
+/**
+ * Read and unmarshal a value from a map representation of vstorage data
+ *
+ * @param {Map<string, string>} data
+ * @param {string} key
+ * @param {ReturnType<typeof import('@endo/marshal').makeMarshal>['fromCapData']} fromCapData
+ * @param {number} [index=-1] index of the desired value in a deserialized stream cell
+ */
+export const unmarshalFromVstorage = (data, key, fromCapData, index = -1) => {
+  const serialized = data.get(key) || Fail`no data for ${key}`;
+  assert.typeof(serialized, 'string');
+
+  const streamCell = JSON.parse(serialized);
+  if (!isStreamCell(streamCell)) {
+    throw Fail`not a StreamCell: ${streamCell}`;
+  }
+
+  const { values } = streamCell;
+  values.length > 0 || Fail`no StreamCell values: ${streamCell}`;
+
+  const marshalled = values.at(index);
+  assert.typeof(marshalled, 'string');
+
+  /** @type {import("@endo/marshal").CapData<string>} */
+  const capData = harden(JSON.parse(marshalled));
+  assertCapData(capData);
+
+  const unmarshalled = fromCapData(capData);
+  return unmarshalled;
+};
+harden(unmarshalFromVstorage);
+
 /**
  * @typedef {object} StoredFacet
  * @property {() => Promise<string>} getPath the chain storage path at which the node was constructed