refactor(time-helper): optionally durable

Agoric · Jun 21, 2024 · ca5d087 · ca5d087
1 parent 92292e7
commit ca5d087
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Showing 5 changed files with 72 additions and 40 deletions.
diff --git a/packages/orchestration/src/examples/stakeBld.contract.js b/packages/orchestration/src/examples/stakeBld.contract.js
@@ -6,6 +6,7 @@ import { prepareRecorderKitMakers } from '@agoric/zoe/src/contractSupport/record
 import { withdrawFromSeat } from '@agoric/zoe/src/contractSupport/zoeHelpers.js';
 import { InvitationShape } from '@agoric/zoe/src/typeGuards.js';
 import { makeDurableZone } from '@agoric/zone/durable.js';
+import { makeHeapZone } from '@agoric/zone';
 import { prepareVowTools, V } from '@agoric/vow/vat.js';
 import { E } from '@endo/far';
 import { deeplyFulfilled } from '@endo/marshal';
@@ -36,21 +37,23 @@ const trace = makeTracer('StakeBld');
  */
 export const start = async (zcf, privateArgs, baggage) => {
   const zone = makeDurableZone(baggage);
+  const { agoricNames, marshaller, timerService } = privateArgs;
 
-  const { makeRecorderKit } = prepareRecorderKitMakers(
-    baggage,
-    privateArgs.marshaller,
-  );
+  const { makeRecorderKit } = prepareRecorderKitMakers(baggage, marshaller);
   const vowTools = prepareVowTools(zone.subZone('vows'));
+  const timeHelper = makeTimeHelper(makeHeapZone(), {
+    timerService,
+    vowTools,
+  });
 
   const makeLocalOrchestrationAccountKit = prepareLocalOrchestrationAccountKit(
     zone,
     makeRecorderKit,
     zcf,
-    privateArgs.timerService,
+    timerService,
     vowTools,
-    makeChainHub(privateArgs.agoricNames),
-    makeTimeHelper(privateArgs.timerService),
+    makeChainHub(agoricNames),
+    timeHelper,
   );
 
   // ----------------

diff --git a/packages/orchestration/src/exos/time-helper.js b/packages/orchestration/src/exos/time-helper.js
@@ -1,46 +1,54 @@
 import { RelativeTimeRecordShape, TimeMath } from '@agoric/time';
 import { VowShape } from '@agoric/vow';
-import { watch, allVows } from '@agoric/vow/vat.js';
-import { makeHeapZone } from '@agoric/zone';
-import { E } from '@endo/far';
+import { E, Far } from '@endo/far';
 import { M } from '@endo/patterns';
 
 /**
  * @import {Remote} from '@agoric/internal';*
  * @import {RelativeTimeRecord, TimerBrand, TimerService, TimestampRecord} from '@agoric/time';
- * @import {Vow} from '@agoric/vow';
+ * @import {Vow, VowTools} from '@agoric/vow';
  * @import {Zone} from '@agoric/zone';
  */
 
 export const SECONDS_PER_MINUTE = 60n;
 export const NANOSECONDS_PER_SECOND = 1_000_000_000n;
 
 /**
- * @param {Remote<TimerService>} timerService
- * @param {Zone} [zone]
+ * @param {Zone} zone
+ * @param {{ timerService: Remote<TimerService>; vowTools: VowTools }} powers
  */
-
-export const makeTimeHelper = (timerService, zone = makeHeapZone()) => {
-  /** @type {TimerBrand | undefined} */
-  let brandCache;
-  const getBrand = () => {
-    if (brandCache) return brandCache;
-    return watch(E(timerService).getTimerBrand(), {
-      onFulfilled: timerBrand => {
-        brandCache = timerBrand;
-        return timerBrand;
-      },
-    });
-  };
-
-  return zone.exo(
+export const makeTimeHelper = (
+  zone,
+  { timerService, vowTools: { watch, allVows } },
+) => {
+  const timeHelper = zone.exoClass(
     'Time Helper',
     M.interface('TimeHelperI', {
       getTimeoutTimestampNS: M.call()
         .optional(RelativeTimeRecordShape)
         .returns(VowShape),
+      getBrand: M.call().returns(VowShape),
     }),
+    () =>
+      /** @type {{ brandCache: TimerBrand | undefined }} */ ({
+        brandCache: undefined,
+      }),
     {
+      /** @returns {Vow<TimerBrand>} */
+      getBrand() {
+        // XXX this is a common use case that should have a helper like `provideSingleton`
+        if (this.state.brandCache) return watch(this.state.brandCache);
+        return watch(
+          E(timerService).getTimerBrand(),
+          Far('BrandWatcher', {
+            /** @param {TimerBrand} timerBrand */
+            onFulfilled: timerBrand => {
+              this.state.brandCache = timerBrand;
+              return timerBrand;
+            },
+          }),
+        );
+      },
       /**
        * Takes the current time from ChainTimerService and adds a relative time
        * to determine a timeout timestamp in nanoseconds. Useful for
@@ -52,8 +60,11 @@ export const makeTimeHelper = (timerService, zone = makeHeapZone()) => {
        */
       getTimeoutTimestampNS(relativeTime) {
         return watch(
-          allVows([E(timerService).getCurrentTimestamp(), getBrand()]),
-          {
+          allVows([
+            E(timerService).getCurrentTimestamp(),
+            this.self.getBrand(),
+          ]),
+          Far('TimestampWatcher', {
             /** @param {[TimestampRecord, TimerBrand]} results */
             onFulfilled([currentTime, timerBrand]) {
               const timeout =
@@ -67,11 +78,13 @@ export const makeTimeHelper = (timerService, zone = makeHeapZone()) => {
                 NANOSECONDS_PER_SECOND
               );
             },
-          },
+          }),
         );
       },
     },
   );
+  return timeHelper();
 };
+harden(makeTimeHelper);
 
-/** @typedef {Awaited<ReturnType<typeof makeTimeHelper>>} TimeHelper */
+/** @typedef {ReturnType<typeof makeTimeHelper>} TimeHelper */
diff --git a/packages/orchestration/src/utils/start-helper.js b/packages/orchestration/src/utils/start-helper.js
@@ -2,6 +2,7 @@ import { prepareAsyncFlowTools } from '@agoric/async-flow';
 import { prepareVowTools } from '@agoric/vow';
 import { prepareRecorderKitMakers } from '@agoric/zoe/src/contractSupport/recorder.js';
 import { makeDurableZone } from '@agoric/zone/durable.js';
+import { makeHeapZone } from '@agoric/zone';
 import { prepareLocalOrchestrationAccountKit } from '../exos/local-orchestration-account.js';
 import { makeOrchestrationFacade } from '../facade.js';
 import { makeChainHub } from '../exos/chain-hub.js';
@@ -46,11 +47,15 @@ export const provideOrchestration = (
   marshaller,
 ) => {
   const zone = makeDurableZone(baggage);
+  const vowTools = prepareVowTools(zone.subZone('vows'));
 
-  const chainHub = makeChainHub(remotePowers.agoricNames);
-  const timeHelper = makeTimeHelper(remotePowers.timerService);
+  const { agoricNames, timerService } = remotePowers;
 
-  const vowTools = prepareVowTools(zone.subZone('vows'));
+  const chainHub = makeChainHub(agoricNames);
+  const timeHelper = makeTimeHelper(makeHeapZone(), {
+    timerService,
+    vowTools,
+  });
 
   const { makeRecorderKit } = prepareRecorderKitMakers(baggage, marshaller);
   const makeLocalOrchestrationAccountKit = prepareLocalOrchestrationAccountKit(

diff --git a/packages/orchestration/test/exos/local-orchestration-account-kit.test.ts b/packages/orchestration/test/exos/local-orchestration-account-kit.test.ts
@@ -4,6 +4,7 @@ import { AmountMath } from '@agoric/ertp';
 import { eventLoopIteration } from '@agoric/internal/src/testing-utils.js';
 import { V as E } from '@agoric/vow/vat.js';
 import { prepareRecorderKitMakers } from '@agoric/zoe/src/contractSupport/recorder.js';
+import { makeHeapZone } from '@agoric/zone';
 import { Far } from '@endo/far';
 import { prepareLocalOrchestrationAccountKit } from '../../src/exos/local-orchestration-account.js';
 import { ChainAddress } from '../../src/orchestration-api.js';
@@ -37,7 +38,7 @@ test('deposit, withdraw', async t => {
     timer,
     vowTools,
     makeChainHub(bootstrap.agoricNames),
-    makeTimeHelper(timer),
+    makeTimeHelper(makeHeapZone(), { timerService: timer, vowTools }),
   );
 
   t.log('request account from vat-localchain');
@@ -109,7 +110,7 @@ test('delegate, undelegate', async t => {
     timer,
     vowTools,
     makeChainHub(bootstrap.agoricNames),
-    makeTimeHelper(timer),
+    makeTimeHelper(makeHeapZone(), { timerService: timer, vowTools }),
   );
 
   t.log('request account from vat-localchain');
@@ -162,7 +163,7 @@ test('transfer', async t => {
     timer,
     vowTools,
     makeChainHub(bootstrap.agoricNames),
-    makeTimeHelper(timer),
+    makeTimeHelper(makeHeapZone(), { timerService: timer, vowTools }),
   );
 
   t.log('request account from vat-localchain');

diff --git a/packages/orchestration/test/exos/time-helper.test.ts b/packages/orchestration/test/exos/time-helper.test.ts
@@ -1,8 +1,9 @@
 /* eslint-disable @jessie.js/safe-await-separator */
 import { test } from '@agoric/zoe/tools/prepare-test-env-ava.js';
-import { V } from '@agoric/vow/vat.js';
+import { prepareVowTools, V } from '@agoric/vow/vat.js';
 import { buildZoeManualTimer } from '@agoric/zoe/tools/manualTimer.js';
 import { TimeMath } from '@agoric/time';
+import { makeHeapZone } from '@agoric/zone';
 import {
   makeTimeHelper,
   NANOSECONDS_PER_SECOND,
@@ -11,15 +12,24 @@ import {
 
 test('makeTimeHelper - getCurrentTimestamp', async t => {
   const timer = buildZoeManualTimer(t.log);
+  const vowTools = prepareVowTools(makeHeapZone());
   const timerBrand = timer.getTimerBrand();
   t.is(timer.getCurrentTimestamp().absValue, 0n, 'current time is 0n');
 
-  const timeHelper = makeTimeHelper(timer);
+  const timeHelper = makeTimeHelper(makeHeapZone(), {
+    timerService: timer,
+    vowTools,
+  });
   t.is(
     await V.when(timeHelper.getTimeoutTimestampNS()),
     5n * SECONDS_PER_MINUTE * NANOSECONDS_PER_SECOND,
     'default timestamp is 5 minutes from current time, in nanoseconds',
   );
+  t.is(
+    await V.when(timeHelper.getBrand()),
+    timerBrand,
+    'brand retrieved cache equals timerBrand',
+  );
 
   t.is(
     await V.when(