node/src/node_snapshotable.cc

#include "node_snapshotable.h"
#include "base_object-inl.h"
#include "debug_utils-inl.h"
#include "node_file.h"
#include "node_v8.h"

namespace node {

using v8::Local;
using v8::Object;
using v8::SnapshotCreator;
using v8::StartupData;

SnapshotableObject::SnapshotableObject(Environment* env,
                                       Local<Object> wrap,
                                       EmbedderObjectType type)
    : BaseObject(env, wrap), type_(type) {
}

const char* SnapshotableObject::GetTypeNameChars() const {
  switch (type_) {
#define V(PropertyName, NativeTypeName)                                        \
  case EmbedderObjectType::k_##PropertyName: {                                 \
    return NativeTypeName::type_name.c_str();                                  \
  }
    SERIALIZABLE_OBJECT_TYPES(V)
#undef V
    default: { UNREACHABLE(); }
  }
}

bool IsSnapshotableType(FastStringKey key) {
#define V(PropertyName, NativeTypeName)                                        \
  if (key == NativeTypeName::type_name) {                                      \
    return true;                                                               \
  }
  SERIALIZABLE_OBJECT_TYPES(V)
#undef V

  return false;
}

void DeserializeNodeInternalFields(Local<Object> holder,
                                   int index,
                                   StartupData payload,
                                   void* env) {
  per_process::Debug(DebugCategory::MKSNAPSHOT,
                     "Deserialize internal field %d of %p, size=%d\n",
                     static_cast<int>(index),
                     (*holder),
                     static_cast<int>(payload.raw_size));
  if (payload.raw_size == 0) {
    holder->SetAlignedPointerInInternalField(index, nullptr);
    return;
  }

  Environment* env_ptr = static_cast<Environment*>(env);
  const InternalFieldInfo* info =
      reinterpret_cast<const InternalFieldInfo*>(payload.data);

  switch (info->type) {
#define V(PropertyName, NativeTypeName)                                        \
  case EmbedderObjectType::k_##PropertyName: {                                 \
    per_process::Debug(DebugCategory::MKSNAPSHOT,                              \
                       "Object %p is %s\n",                                    \
                       (*holder),                                              \
                       NativeTypeName::type_name.c_str());                     \
    env_ptr->EnqueueDeserializeRequest(                                        \
        NativeTypeName::Deserialize, holder, index, info->Copy());             \
    break;                                                                     \
  }
    SERIALIZABLE_OBJECT_TYPES(V)
#undef V
    default: { UNREACHABLE(); }
  }
}

StartupData SerializeNodeContextInternalFields(Local<Object> holder,
                                               int index,
                                               void* env) {
  per_process::Debug(DebugCategory::MKSNAPSHOT,
                     "Serialize internal field, index=%d, holder=%p\n",
                     static_cast<int>(index),
                     *holder);
  void* ptr = holder->GetAlignedPointerFromInternalField(BaseObject::kSlot);
  if (ptr == nullptr) {
    return StartupData{nullptr, 0};
  }

  DCHECK(static_cast<BaseObject*>(ptr)->is_snapshotable());
  SnapshotableObject* obj = static_cast<SnapshotableObject*>(ptr);
  per_process::Debug(DebugCategory::MKSNAPSHOT,
                     "Object %p is %s, ",
                     *holder,
                     obj->GetTypeNameChars());
  InternalFieldInfo* info = obj->Serialize(index);
  per_process::Debug(DebugCategory::MKSNAPSHOT,
                     "payload size=%d\n",
                     static_cast<int>(info->length));
  return StartupData{reinterpret_cast<const char*>(info),
                     static_cast<int>(info->length)};
}

void SerializeBindingData(Environment* env,
                          SnapshotCreator* creator,
                          EnvSerializeInfo* info) {
  size_t i = 0;
  env->ForEachBindingData([&](FastStringKey key,
                              BaseObjectPtr<BaseObject> binding) {
    per_process::Debug(DebugCategory::MKSNAPSHOT,
                       "Serialize binding %i, %p, type=%s\n",
                       static_cast<int>(i),
                       *(binding->object()),
                       key.c_str());

    if (IsSnapshotableType(key)) {
      size_t index = creator->AddData(env->context(), binding->object());
      per_process::Debug(DebugCategory::MKSNAPSHOT,
                         "Serialized with index=%d\n",
                         static_cast<int>(index));
      info->bindings.push_back({key.c_str(), i, index});
      SnapshotableObject* ptr = static_cast<SnapshotableObject*>(binding.get());
      ptr->PrepareForSerialization(env->context(), creator);
    } else {
      UNREACHABLE();
    }

    i++;
  });
}

}  // namespace node