Keep cold Candidate verification cooperative with controller renewals

src/capability-model/evolution.ts

@@ -1,4 +1,5 @@
 import { createHash } from "node:crypto";
+import { setImmediate } from "node:timers/promises";
 import type { Binding, Conformance, DependencyBinding, PersistentAttachment, WorkspaceRevision } from "./types.js";
 import { validateWorkspaceRevision } from "./validation.js";
 
@@ -21,6 +22,52 @@ export const canonicalJson = (value: unknown): string => {
 };
 export const contentDigest = (value: unknown) =>
   `sha256:${createHash("sha256").update(canonicalJson(value)).digest("hex")}`;
+/** Same canonical bytes as contentDigest, without monopolizing a live host's
+ * event loop while verifying large immutable metadata. No validation is skipped.
+ * This is for asynchronous loading, not a different build/wire identity. */
+export async function contentDigestAsync(value: unknown): Promise<string> {
+  function* parts(value: unknown): Generator<string> {
+    if (Array.isArray(value)) {
+      yield "[";
+      for (let index = 0; index < value.length; index++) {
+        if (index) yield ",";
+        // Match canonicalJson's Array.map behavior for sparse arrays too.
+        if (index in value) yield* parts(value[index]);
+      }
+      yield "]";
+    } else if (value !== null && typeof value === "object") {
+      if (Object.getPrototypeOf(value) !== Object.prototype && Object.getPrototypeOf(value) !== null)
+        throw new Error("Expected a plain JSON object");
+      yield "{";
+      let first = true;
+      for (const key of Object.keys(value).sort(compareText)) {
+        const entry = (value as Record<string, unknown>)[key];
+        if (entry === undefined) continue;
+        if (!first) yield ",";
+        first = false;
+        yield JSON.stringify(key) + ":";
+        yield* parts(entry);
+      }
+      yield "}";
+    } else yield canonicalJson(value);
+  }
+  const hash = createHash("sha256");
+  let buffer = "",
+    sliceStarted = performance.now();
+  for (const part of parts(value)) {
+    buffer += part;
+    if (buffer.length >= 65536) {
+      hash.update(buffer);
+      buffer = "";
+      if (performance.now() - sliceStarted >= 8) {
+        await setImmediate();
+        sliceStarted = performance.now();
+      }
+    }
+  }
+  hash.update(buffer);
+  return `sha256:${hash.digest("hex")}`;
+}
 const semantic = (value: unknown): unknown => {
   if (Array.isArray(value)) return value.map(semantic);
   if (value && typeof value === "object")

src/execution-world/artifacts.ts

@@ -1,6 +1,13 @@
 import { createHash } from "node:crypto";
 import { canonicalJson } from "../capability-model/evolution.js";
-import { type ExecutionPlan, type PlanPackage, ExecutionPlanError, hexDigest, executionVersions } from "./plan.js";
+import {
+  type ExecutionPlan,
+  type PlanPackage,
+  ExecutionPlanError,
+  hexDigest,
+  hexDigestAsync,
+  executionVersions,
+} from "./plan.js";
 
 export interface ArtifactFile {
   path: string;
@@ -359,7 +366,7 @@ export async function checkExecutionWorld(
 ): Promise<CheckedWorld> {
   if (canonicalJson(plan.definition.versions) !== canonicalJson(executionVersions))
     fail("world", "Unsupported plan codec versions");
-  if (hexDigest(plan.definition) !== plan.digest) fail("plan", "Plan digest mismatch");
+  if ((await hexDigestAsync(plan.definition)) !== plan.digest) fail("plan", "Plan digest mismatch");
   const manifests = inputs.map(parsePackageArtifacts);
   unique(
     manifests.map((m) => m.packageRevisionId),

src/execution-world/candidate.ts

@@ -1,7 +1,7 @@
 import { graphExecutionRepresentation } from "./graph-execution.js";
 import { lstat } from "node:fs/promises";
 import { join } from "node:path";
-import { hexDigest, ExecutionPlanError, type ExecutionPlan } from "./plan.js";
+import { hexDigest, hexDigestAsync, ExecutionPlanError, type ExecutionPlan } from "./plan.js";
 import {
   loadExecutionInstallation,
   createClientContractCatalog,
@@ -50,7 +50,7 @@ export async function loadCheckedInstallationCandidate(
       const input = await readJson(root, "candidate.json", scope);
       try {
         const { executionContracts: _legacyContracts, ...workspace } = input.value;
-        return hexDigest(workspace);
+        return await hexDigestAsync(workspace);
       } finally {
         input.releaseTree();
       }
@@ -72,8 +72,8 @@ export async function loadCheckedInstallationCandidate(
     const [plan, artifacts, source, entryRequest, kernel, queries] = values;
     if (
       plan?.definition?.codec !== "camino-execution-plan-v1" ||
-      hexDigest(plan.definition) !== plan.digest ||
+      (await hexDigestAsync(plan.definition)) !== plan.digest ||
-      workspaceDigest !== hexDigest(plan.definition.workspace)
+      workspaceDigest !== (await hexDigestAsync(plan.definition.workspace))
     )
       throw new ExecutionPlanError(
         "CANDIDATE_PLAN_MISMATCH",
@@ -117,7 +117,11 @@ export async function loadCheckedInstallationCandidate(
       ["kernel", kernel, "camino-kernel-program-v1"],
       ["queries", queries, "camino-query-program-v1"],
     ] as const)
-      if (program?.codec !== codec || program.plan !== kernel.plan || hexDigest(program) !== artifacts.programs?.[name])
+      if (
+        program?.codec !== codec ||
+        program.plan !== kernel.plan ||
+        (await hexDigestAsync(program)) !== artifacts.programs?.[name]
+      )
         throw new ExecutionPlanError(
           "CANDIDATE_PROGRAM_MISMATCH",
           name,
@@ -129,8 +133,8 @@ export async function loadCheckedInstallationCandidate(
     await (async () => {
       const input = await readJson(root, "graph-execution.json", scope);
       try {
-        const digest = hexDigest(input.value);
+        const digest = await hexDigestAsync(input.value);
-        if (digest !== hexDigest(expectedGraph) || artifacts.execution !== digest)
+        if (digest !== (await hexDigestAsync(expectedGraph)) || artifacts.execution !== digest)
           throw new ExecutionPlanError(
             "CANDIDATE_EXECUTION_MISMATCH",
             root,
@@ -164,7 +168,7 @@ export async function loadCheckedInstallationCandidate(
     return {
       reference,
       workspace: plan.definition.workspace.workspaceId,
-      world: hexDigest(expectedGraph),
+      world: await hexDigestAsync(expectedGraph),
       plan: kernel.plan as string,
       graphExecution: expectedGraph,
       provenance,

src/execution-world/plan.ts

@@ -11,7 +11,7 @@ import type {
   OperationId,
 } from "../capability-model/types.js";
 import { validateWorkspaceRevision } from "../capability-model/validation.js";
-import { canonicalJson, contentDigest } from "../capability-model/evolution.js";
+import { canonicalJson, contentDigest, contentDigestAsync } from "../capability-model/evolution.js";
 import { resolveForwardedBinding } from "../capability-model/forwarding.js";
 import { linkQueries, type LinkedQuery } from "../query/link.js";
 import { type BindingSchema } from "../bindings/index.js";
@@ -29,6 +29,8 @@ export class ExecutionPlanError extends Error {
   }
 }
 export const hexDigest = (value: unknown): string => contentDigest(value).slice("sha256:".length);
+export const hexDigestAsync = async (value: unknown): Promise<string> =>
+  (await contentDigestAsync(value)).slice("sha256:".length);
 const sorted = <T>(values: readonly T[], key: (value: T) => string): T[] =>
   [...values].sort((a, b) => (key(a) < key(b) ? -1 : key(a) > key(b) ? 1 : 0));
 export const publicOperationKey = (atom: string, iface: string, operation: string): string =>

test/evolution.test.ts

@@ -3,6 +3,7 @@ import { test } from "node:test";
 import { capabilityId as id, valueType, validateWorkspaceRevision } from "../src/capability-model/index.js";
 import {
   contentDigest,
+  contentDigestAsync,
   planEvolution,
   reviewSemanticMajors,
   runtimeContracts,
@@ -51,6 +52,27 @@ test("hashing is canonical and rejects values outside the persisted JSON contrac
   assert.throws(() => contentDigest(new Date()));
 });
 
+test("cooperative hashing preserves canonical identities and services the event loop", async () => {
+  const sparse = [1, 2, 3];
+  delete sparse[1];
+  const values = [null, false, -0, "中\\n\ud800", sparse, { z: 1, a: { omitted: undefined, b: [false, 1e100] } }];
+  for (const value of values) assert.equal(await contentDigestAsync(value), contentDigest(value));
+  for (const value of [undefined, NaN, Infinity, new Date(), [undefined]])
+    await assert.rejects(contentDigestAsync(value));
+  const large = Array.from({ length: 50000 }, (_, index) => ({ z: "definition".repeat(8), a: index }));
+  const expected = contentDigest(large);
+  let serviced = false;
+  const timer = setTimeout(() => {
+    serviced = true;
+  }, 0);
+  try {
+    assert.equal(await contentDigestAsync(large), expected);
+    assert.equal(serviced, true, "large verification must let host renewals and RPCs run");
+  } finally {
+    clearTimeout(timer);
+  }
+});
+
 test("a workspace root change and display names do not restart package runtimes", () => {
   const before = makeValidCapabilityWorkspace();
   const after = structuredClone(before);