src: implement IsolateData serialization and deserialization

This patch allows serializing per-isolate data into an isolate
snapshot and deserializing them from an isolate snapthot.

PR-URL: https://github.com/nodejs/node/pull/27321
Refs: https://github.com/nodejs/node/issues/17058
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

1 files changed, 18 insertions, 1 deletions

diff --git a/src/node_main_instance.h b/src/node_main_instance.h
index 0a8be137a0..615fda1f49 100644
--- a/src/node_main_instance.h
+++ b/src/node_main_instance.h
@@ -15,6 +15,18 @@ namespace node {
 // We may be able to create an abstract class to reuse some of the routines.
 class NodeMainInstance {
  public:
+  // An array of indexes that can be used to deserialize data from a V8
+  // snapshot.
+  struct IndexArray {
+    const size_t* data;
+    size_t length;
+
+    size_t Get(size_t index) const {
+      DCHECK_LT(index, length);
+      return data[index];
+    }
+  };
+
   // To create a main instance that does not own the isoalte,
   // The caller needs to do:
   //
@@ -45,12 +57,15 @@ class NodeMainInstance {
                    uv_loop_t* event_loop,
                    MultiIsolatePlatform* platform,
                    const std::vector<std::string>& args,
-                   const std::vector<std::string>& exec_args);
+                   const std::vector<std::string>& exec_args,
+                   const IndexArray* per_isolate_data_indexes = nullptr);
   ~NodeMainInstance();
 
   // Start running the Node.js instances, return the exit code when finished.
   int Run();
 
+  IsolateData* isolate_data() { return isolate_data_.get(); }
+
   // TODO(joyeecheung): align this with the CreateEnvironment exposed in node.h
   // and the environment creation routine in workers somehow.
   std::unique_ptr<Environment> CreateMainEnvironment(int* exit_code);
@@ -66,6 +81,7 @@ class NodeMainInstance {
                    MultiIsolatePlatform* platform,
                    const std::vector<std::string>& args,
                    const std::vector<std::string>& exec_args);
+
   std::vector<std::string> args_;
   std::vector<std::string> exec_args_;
   std::unique_ptr<ArrayBufferAllocator> array_buffer_allocator_;
@@ -73,6 +89,7 @@ class NodeMainInstance {
   MultiIsolatePlatform* platform_;
   std::unique_ptr<IsolateData> isolate_data_;
   bool owns_isolate_ = false;
+  bool deserialize_mode_ = false;
 };
 
 }  // namespace node