policy: add startup benchmark and make SRI lazier

PR-URL: https://github.com/nodejs/node/pull/29527
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

benchmark/policy/policy-startup.js

@@ -0,0 +1,51 @@
+// Tests the impact on eager operations required for policies affecting
+// general startup,  does not test lazy operations
+'use strict';
+const common = require('../common.js');
+
+const configs = {
+  n: [1024]
+};
+
+const options = {
+  flags: ['--expose-internals']
+};
+
+const bench = common.createBenchmark(main, configs, options);
+
+function main(conf) {
+  const hash = (str, algo) => {
+    const hash = require('crypto').createHash(algo);
+    return hash.update(str).digest('base64');
+  };
+  const resources = Object.fromEntries(
+    // Simulate graph of 1k modules
+    Array.from({ length: 1024 }, (_, i) => {
+      return [`./_${i}`, {
+        integrity: `sha256-${hash(`// ./_${i}`, 'sha256')}`,
+        dependencies: Object.fromEntries(Array.from({
+          // Average 3 deps per 4 modules
+          length: Math.floor((i % 4) / 2)
+        }, (_, ii) => {
+          return [`_${ii}`, `./_${i - ii}`];
+        })),
+      }];
+    })
+  );
+  const json = JSON.parse(JSON.stringify({ resources }), (_, o) => {
+    if (o && typeof o === 'object') {
+      Reflect.setPrototypeOf(o, null);
+      Object.freeze(o);
+    }
+    return o;
+  });
+  const { Manifest } = require('internal/policy/manifest');
+
+  bench.start();
+
+  for (let i = 0; i < conf.n; i++) {
+    new Manifest(json, 'file://benchmark/policy-relative');
+  }
+
+  bench.end(conf.n);
+}