Allow starting isolate from snapshot bytes on the heap (#5187)

core/isolate.rs

@@ -125,6 +125,7 @@ impl From<Script<'_>> for OwnedScript {
 pub enum Snapshot {
  Static(&'static [u8]),
  JustCreated(v8::StartupData),
+ Boxed(Box<[u8]>),
 }
 
 /// Represents data used to initialize isolate at startup
@@ -250,6 +251,7 @@ impl CoreIsolate {
  params = match snapshot {
  Snapshot::Static(data) => params.snapshot_blob(data),
  Snapshot::JustCreated(data) => params.snapshot_blob(data),
+ Snapshot::Boxed(data) => params.snapshot_blob(data),
  };
  true
  } else {
@@ -1175,6 +1177,20 @@ pub mod tests {
  let mut isolate2 = CoreIsolate::new(startup_data, false);
  js_check(isolate2.execute("check.js", "if (a != 3) throw Error('x')"));
  }
+
+ #[test]
+ fn test_from_boxed_snapshot() {
+ let snapshot = {
+ let mut isolate = CoreIsolate::new(StartupData::None, true);
+ js_check(isolate.execute("a.js", "a = 1 + 2"));
+ let snap: &[u8] = &*isolate.snapshot();
+ Vec::from(snap).into_boxed_slice()
+ };
+
+ let startup_data = StartupData::Snapshot(Snapshot::Boxed(snapshot));
+ let mut isolate2 = CoreIsolate::new(startup_data, false);
+ js_check(isolate2.execute("check.js", "if (a != 3) throw Error('x')"));
+ }
 }
 
 // TODO(piscisaureus): rusty_v8 should implement the Error trait on