core: snapshot improvements (#2052)

* Moves how snapshots are supplied to the Isolate. Previously they were
  given by Behavior::startup_data() but it was only called once at
  startup. It makes more sense (and simplifies Behavior) to pass it to the
  constructor of Isolate.
* Adds new libdeno type deno_snapshot instead of overloading
  deno_buf.
* Adds new libdeno method to delete snapshot deno_snapshot_delete().
* Renames deno_get_snapshot() to deno_snapshot_new().
* Makes StartupData hold references to snapshots. This was implicit when
  it previously held a deno_buf but is made explicit now. Note that
  include_bytes!() returns a &'static [u8] and we want to avoid
  copying that.

1 files changed, 7 insertions, 3 deletions

diff --git a/core/libdeno/api.cc b/core/libdeno/api.cc
index fa1fe92f9..ad9c2a574 100644
--- a/core/libdeno/api.cc
+++ b/core/libdeno/api.cc
@@ -93,7 +93,7 @@ void deno_unlock(Deno* d_) {
   d->locker_ = nullptr;
 }
 
-deno_buf deno_get_snapshot(Deno* d_) {
+deno_snapshot deno_snapshot_new(Deno* d_) {
   auto* d = unwrap(d_);
   CHECK_NOT_NULL(d->snapshot_creator_);
   d->ClearModules();
@@ -101,8 +101,12 @@ deno_buf deno_get_snapshot(Deno* d_) {
 
   auto blob = d->snapshot_creator_->CreateBlob(
       v8::SnapshotCreator::FunctionCodeHandling::kKeep);
-  return {nullptr, 0, reinterpret_cast<uint8_t*>(const_cast<char*>(blob.data)),
-          blob.raw_size, 0};
+  return {reinterpret_cast<uint8_t*>(const_cast<char*>(blob.data)),
+          blob.raw_size};
+}
+
+void deno_snapshot_delete(deno_snapshot snapshot) {
+  delete[] snapshot.data_ptr;
 }
 
 static std::unique_ptr<v8::Platform> platform;