vm: introduce `cachedData`/`produceCachedData`

Introduce `cachedData`/`produceCachedData` options for `v8.Script`.
Could be used to consume/produce V8's code cache for speeding up
compilation of known code.

PR-URL: https://github.com/nodejs/node/pull/4777
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

1 files changed, 37 insertions, 0 deletions

diff --git a/test/parallel/test-vm-cached-data.js b/test/parallel/test-vm-cached-data.js
new file mode 100644
index 0000000000..47ea592b53
--- /dev/null
+++ b/test/parallel/test-vm-cached-data.js
@@ -0,0 +1,37 @@
+'use strict';
+require('../common');
+const assert = require('assert');
+const vm = require('vm');
+const Buffer = require('buffer').Buffer;
+
+const originalSource = '(function bcd() { return \'original\'; })';
+
+// It should produce code cache
+const original = new vm.Script(originalSource, {
+  produceCachedData: true
+});
+assert(original.cachedData instanceof Buffer);
+
+assert.equal(original.runInThisContext()(), 'original');
+
+// It should consume code cache
+const success = new vm.Script(originalSource, {
+  cachedData: original.cachedData
+});
+assert(!success.cachedDataRejected);
+
+assert.equal(success.runInThisContext()(), 'original');
+
+// It should reject invalid code cache
+const reject = new vm.Script('(function abc() { return \'invalid\'; })', {
+  cachedData: original.cachedData
+});
+assert(reject.cachedDataRejected);
+assert.equal(reject.runInThisContext()(), 'invalid');
+
+// It should throw on non-Buffer cachedData
+assert.throws(() => {
+  new vm.Script('function abc() {}', {
+    cachedData: 'ohai'
+  });
+});