Reland "Encode reservation meta data in the snapshot blob."

src/snapshot-common.cc

 // 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.
 
 // The common functionality when building with or without snapshots.
 
 #include "src/v8.h"
 
 #include "src/api.h"
 #include "src/base/platform/platform.h"
 #include "src/serialize.h"
 #include "src/snapshot.h"
 
 namespace v8 {
 namespace internal {
 
-void Snapshot::ReserveSpaceForLinkedInSnapshot(Deserializer* deserializer) {
-  deserializer->AddReservation(NEW_SPACE, new_space_used_);
-  deserializer->AddReservation(OLD_POINTER_SPACE, pointer_space_used_);
-  deserializer->AddReservation(OLD_DATA_SPACE, data_space_used_);
-  deserializer->AddReservation(CODE_SPACE, code_space_used_);
-  deserializer->AddReservation(MAP_SPACE, map_space_used_);
-  deserializer->AddReservation(CELL_SPACE, cell_space_used_);
-  deserializer->AddReservation(PROPERTY_CELL_SPACE, property_cell_space_used_);
-  deserializer->AddReservation(LO_SPACE, lo_space_used_);
-}
-
 
 bool Snapshot::Initialize(Isolate* isolate) {
   if (size_ > 0) {
     base::ElapsedTimer timer;
-    if (FLAG_profile_deserialization) {
-      timer.Start();
-    }
-    SnapshotByteSource source(raw_data_, raw_size_);
-    Deserializer deserializer(&source);
-    ReserveSpaceForLinkedInSnapshot(&deserializer);
+    if (FLAG_profile_deserialization) timer.Start();
+
+    SnapshotData snapshot_data(data_, size_);
+    Deserializer deserializer(&snapshot_data);
     bool success = isolate->Init(&deserializer);
     if (FLAG_profile_deserialization) {
       double ms = timer.Elapsed().InMillisecondsF();
       PrintF("[Snapshot loading and deserialization took %0.3f ms]\n", ms);
     }
     return success;
   }
   return false;
 }
 
 
 bool Snapshot::HaveASnapshotToStartFrom() {
   return size_ != 0;
 }
 
 
 Handle<Context> Snapshot::NewContextFromSnapshot(Isolate* isolate) {
-  if (context_size_ == 0) {
-    return Handle<Context>();
-  }
-  SnapshotByteSource source(context_raw_data_,
-                            context_raw_size_);
-  Deserializer deserializer(&source);
+  if (context_size_ == 0) return Handle<Context>();
+
+  SnapshotData snapshot_data(context_data_, context_size_);
+  Deserializer deserializer(&snapshot_data);
   Object* root;
-  deserializer.AddReservation(NEW_SPACE, context_new_space_used_);
-  deserializer.AddReservation(OLD_POINTER_SPACE, context_pointer_space_used_);
-  deserializer.AddReservation(OLD_DATA_SPACE, context_data_space_used_);
-  deserializer.AddReservation(CODE_SPACE, context_code_space_used_);
-  deserializer.AddReservation(MAP_SPACE, context_map_space_used_);
-  deserializer.AddReservation(CELL_SPACE, context_cell_space_used_);
-  deserializer.AddReservation(PROPERTY_CELL_SPACE,
-                              context_property_cell_space_used_);
-  deserializer.AddReservation(LO_SPACE, context_lo_space_used_);
   deserializer.DeserializePartial(isolate, &root);
   CHECK(root->IsContext());
   return Handle<Context>(Context::cast(root));
 }
 
 
 #ifdef V8_USE_EXTERNAL_STARTUP_DATA
 // Dummy implementations of Set*FromFile(..) APIs.
 //
 // These are meant for use with snapshot-external.cc. Should this file
 // be compiled with those options we just supply these dummy implementations
 // below. This happens when compiling the mksnapshot utility.
 void SetNativesFromFile(StartupData* data) { CHECK(false); }
 void SetSnapshotFromFile(StartupData* data) { CHECK(false); }
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
 
 } }  // namespace v8::internal