n-api: support type-tagging objects

`napi_instanceof()` is insufficient for reliably establishing the data
type to which a pointer stored with `napi_wrap()` or
`napi_create_external()` inside a JavaScript object points. Thus, we
need a way to "mark" an object with a value that, when later retrieved,
can unambiguously tell us whether it is safe to cast the pointer stored
inside it to a certain structure.

Such a check must survive loading/unloading/multiple instances of an
addon, so we use UUIDs chosen *a priori*.

Fixes: https://github.com/nodejs/node/issues/28164
Co-authored-by: Anna Henningsen <github@addaleax.net>
PR-URL: https://github.com/nodejs/node/pull/28237
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Signed-off-by: Gabriel Schulhof <gabriel.schulhof@intel.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/benchmark/napi/type-tag/check-object-tag.js b/benchmark/napi/type-tag/check-object-tag.js
new file mode 100644
index 00000000000..346dfb7812d
--- /dev/null
+++ b/benchmark/napi/type-tag/check-object-tag.js
@@ -0,0 +1,18 @@
+'use strict';
+const common = require('../../common.js');
+
+let binding;
+try {
+  binding = require(`./build/${common.buildType}/binding`);
+} catch {
+  console.error(`${__filename}: Binding failed to load`);
+  process.exit(0);
+}
+
+const bench = common.createBenchmark(main, {
+  n: [1e5, 1e6, 1e7],
+});
+
+function main({ n }) {
+  binding.checkObjectTag(n, bench, bench.start, bench.end);
+}