Support external startup data in V8. (retry)

src/snapshot-external.cc

Index: src/snapshot-external.cc
diff --git a/src/snapshot-external.cc b/src/snapshot-external.cc
new file mode 100644
index 0000000000000000000000000000000000000000..5bfadc2a6354fe95de3bcf9369c7daaac6115911
--- /dev/null
+++ b/src/snapshot-external.cc
@@ -0,0 +1,140 @@
+// Copyright 2006-2008 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Used for building with external snapshots.
+
+#include "src/snapshot.h"
+
+#include "src/v8.h"  // for V8::Initialize
+#include "src/serialize.h"
+#include "src/snapshot-source-sink.h"
+
+namespace v8 {
+namespace internal {
+
+
+struct SnapshotImpl {
+ public:
+  const byte* data;
+  int size;
+  int new_space_used;
+  int pointer_space_used;
+  int data_space_used;
+  int code_space_used;
+  int map_space_used;
+  int cell_space_used;
+  int property_cell_space_used;
+
+  const byte* context_data;
+  int context_size;
+  int context_new_space_used;
+  int context_pointer_space_used;
+  int context_data_space_used;
+  int context_code_space_used;
+  int context_map_space_used;
+  int context_cell_space_used;
+  int context_property_cell_space_used;
+};
+
+
+static SnapshotImpl* snapshot_impl_ = NULL;
+
+
+bool Snapshot::HaveASnapshotToStartFrom() {
+  return snapshot_impl_ != NULL;
+}
+
+
+bool Snapshot::Initialize() {
+  if (!HaveASnapshotToStartFrom())
+    return false;
+
+  ElapsedTimer timer;
+  if (FLAG_profile_deserialization) {
+    timer.Start();
+  }
+  SnapshotByteSource source(snapshot_impl_->data, snapshot_impl_->size);
+  Deserializer deserializer(&source);
+  deserializer.set_reservation(NEW_SPACE, snapshot_impl_->new_space_used);
+  deserializer.set_reservation(OLD_POINTER_SPACE,
+                               snapshot_impl_->pointer_space_used);
+  deserializer.set_reservation(OLD_DATA_SPACE,
+                               snapshot_impl_->data_space_used);
+  deserializer.set_reservation(CODE_SPACE, snapshot_impl_->code_space_used);
+  deserializer.set_reservation(MAP_SPACE, snapshot_impl_->map_space_used);
+  deserializer.set_reservation(CELL_SPACE, snapshot_impl_->cell_space_used);
+  deserializer.set_reservation(PROPERTY_CELL_SPACE,
+                               snapshot_impl_->property_cell_space_used);
+  bool success = V8::Initialize(&deserializer);
+  if (FLAG_profile_deserialization) {
+    double ms = timer.Elapsed().InMillisecondsF();
+    PrintF("[Snapshot loading and deserialization took %0.3f ms]\n", ms);
+  }
+  return success;
+}
+
+
+Handle<Context> Snapshot::NewContextFromSnapshot(Isolate* isolate) {
+  if (!HaveASnapshotToStartFrom())
+    return Handle<Context>();
+
+  SnapshotByteSource source(snapshot_impl_->context_data,
+                            snapshot_impl_->context_size);
+  Deserializer deserializer(&source);
+  deserializer.set_reservation(NEW_SPACE,
+                               snapshot_impl_->context_new_space_used);
+  deserializer.set_reservation(OLD_POINTER_SPACE,
+                               snapshot_impl_->context_pointer_space_used);
+  deserializer.set_reservation(OLD_DATA_SPACE,
+                               snapshot_impl_->context_data_space_used);
+  deserializer.set_reservation(CODE_SPACE,
+                               snapshot_impl_->context_code_space_used);
+  deserializer.set_reservation(MAP_SPACE,
+                               snapshot_impl_->context_map_space_used);
+  deserializer.set_reservation(CELL_SPACE,
+                               snapshot_impl_->context_cell_space_used);
+  deserializer.set_reservation(PROPERTY_CELL_SPACE,
+                               snapshot_impl_->
+                                   context_property_cell_space_used);
+  Object* root;
+  deserializer.DeserializePartial(isolate, &root);
+  CHECK(root->IsContext());
+  return Handle<Context>(Context::cast(root));
+}
+
+
+void SetSnapshotFromFile(StartupData* snapshot_blob) {
+  ASSERT(snapshot_blob);
+  ASSERT(snapshot_blob->data);
+  ASSERT(snapshot_blob->raw_size > 0);
+  ASSERT(!snapshot_impl_);
+
+  snapshot_impl_ = new SnapshotImpl;
+  SnapshotByteSource source(reinterpret_cast<const byte*>(snapshot_blob->data),
+                            snapshot_blob->raw_size);
+
+  bool success = source.GetBlob(&snapshot_impl_->data,
+                                &snapshot_impl_->size);
+  snapshot_impl_->new_space_used = source.GetInt();
+  snapshot_impl_->pointer_space_used = source.GetInt();
+  snapshot_impl_->data_space_used = source.GetInt();
+  snapshot_impl_->code_space_used = source.GetInt();
+  snapshot_impl_->map_space_used = source.GetInt();
+  snapshot_impl_->cell_space_used = source.GetInt();
+  snapshot_impl_->property_cell_space_used = source.GetInt();
+
+  success &= source.GetBlob(&snapshot_impl_->context_data,
+                            &snapshot_impl_->context_size);
+  snapshot_impl_->context_new_space_used = source.GetInt();
+  snapshot_impl_->context_pointer_space_used = source.GetInt();
+  snapshot_impl_->context_data_space_used = source.GetInt();
+  snapshot_impl_->context_code_space_used = source.GetInt();
+  snapshot_impl_->context_map_space_used = source.GetInt();
+  snapshot_impl_->context_cell_space_used = source.GetInt();
+  snapshot_impl_->context_property_cell_space_used = source.GetInt();
+
+  ASSERT(success);
+}
+
+} }  // namespace v8::internal