Advance M7 workflows and release operations

web/protocol/engine-variant.ts

@@ -0,0 +1,96 @@
+import { blockedGate, capabilityIssue, readyGate, type CapabilityGateResult } from "./capability-gates";
+import type { WebEngineManifestV2, WebEngineVariantV2 } from "./manifest";
+
+export interface WasmThreadingCapabilities {
+  crossOriginIsolated: boolean;
+  sharedArrayBuffer: boolean;
+  worker: boolean;
+}
+
+export type WebEngineVariantPolicy = "AUTO" | "SINGLE_REQUIRED" | "PTHREAD_REQUIRED";
+
+export interface WebEngineVariantSelection {
+  policy: WebEngineVariantPolicy;
+  selectedVariant: WebEngineVariantV2 | null;
+  pthreadGate: CapabilityGateResult;
+}
+
+export type WebEngineReleaseBinding =
+  | { status: "READY"; releaseId: string; manifest: WebEngineManifestV2 }
+  | {
+    status: "REFRESH_REQUIRED";
+    expectedReleaseId: string;
+    actualReleaseId: string;
+    manifest: null;
+  };
+
+export function bindWebEngineRelease(
+  expectedReleaseId: string,
+  manifest: WebEngineManifestV2,
+): WebEngineReleaseBinding {
+  if (manifest.releaseId === expectedReleaseId) {
+    return { status: "READY", releaseId: manifest.releaseId, manifest };
+  }
+  return {
+    status: "REFRESH_REQUIRED",
+    expectedReleaseId,
+    actualReleaseId: manifest.releaseId,
+    manifest: null,
+  };
+}
+
+export function gateWasmThreadingCapability(capabilities: WasmThreadingCapabilities): CapabilityGateResult {
+  const issues = [];
+  if (!capabilities.crossOriginIsolated) {
+    issues.push(capabilityIssue(
+      "PLATFORM_CAPABILITY_UNAVAILABLE",
+      "Cross-origin isolation is required for the pthread WASM engine",
+      "crossOriginIsolated",
+    ));
+  }
+  if (!capabilities.sharedArrayBuffer) {
+    issues.push(capabilityIssue(
+      "PLATFORM_CAPABILITY_UNAVAILABLE",
+      "SharedArrayBuffer is required for the pthread WASM engine",
+      "sharedArrayBuffer",
+    ));
+  }
+  if (!capabilities.worker) {
+    issues.push(capabilityIssue(
+      "PLATFORM_CAPABILITY_UNAVAILABLE",
+      "Worker is required for the pthread WASM engine",
+      "worker",
+    ));
+  }
+  return issues.length > 0
+    ? blockedGate("M6-02", "WASM_PTHREAD_ENGINE", issues)
+    : readyGate("M6-02", "WASM_PTHREAD_ENGINE");
+}
+
+export function selectWebEngineVariant(
+  manifest: WebEngineManifestV2,
+  policy: WebEngineVariantPolicy,
+  capabilities: WasmThreadingCapabilities,
+): WebEngineVariantSelection {
+  const single = manifest.variants.find((variant) => variant.id === "single");
+  const pthread = manifest.variants.find((variant) => variant.id === "pthread");
+  if (!single || !pthread) throw new Error("ENGINE_MANIFEST_VARIANTS_MISSING");
+
+  const pthreadGate = gateWasmThreadingCapability(capabilities);
+  if (policy === "SINGLE_REQUIRED") return { policy, selectedVariant: single, pthreadGate };
+  if (policy === "AUTO") {
+    return {
+      policy,
+      selectedVariant: pthreadGate.status === "READY" ? pthread : single,
+      pthreadGate,
+    };
+  }
+  if (policy === "PTHREAD_REQUIRED") {
+    return {
+      policy,
+      selectedVariant: pthreadGate.status === "READY" ? pthread : null,
+      pthreadGate,
+    };
+  }
+  throw new Error("ENGINE_VARIANT_POLICY_INVALID");
+}