src: track memory size of WebAssembly streaming

src/node_wasm_web_api.cc

@@ -1,5 +1,6 @@
 #include "node_wasm_web_api.h"
 
+#include "memory_tracker-inl.h"
 #include "node_errors.h"
 
 namespace node {
@@ -32,6 +33,13 @@ void WasmStreamingObject::RegisterExternalReferences(
   registry->Register(Abort);
 }
 
+void WasmStreamingObject::MemoryInfo(MemoryTracker* tracker) const {
+  // v8::WasmStreaming is opaque. We assume that the size of the WebAssembly
+  // module that is being compiled is roughly what V8 allocates (as in, off by
+  // only a small factor).
+  tracker->TrackFieldWithSize("streaming", wasm_size_);
+}
+
 v8::MaybeLocal<v8::Object> WasmStreamingObject::Create(
     Environment* env, std::shared_ptr<v8::WasmStreaming> streaming) {
   v8::Local<v8::Function> ctor = Initialize(env);
@@ -45,6 +53,7 @@ v8::MaybeLocal<v8::Object> WasmStreamingObject::Create(
   WasmStreamingObject* ptr = Unwrap<WasmStreamingObject>(obj);
   CHECK_NOT_NULL(ptr);
   ptr->streaming_ = streaming;
+  ptr->wasm_size_ = 0;
   return obj;
 }
 
@@ -88,6 +97,7 @@ void WasmStreamingObject::Push(
   // Forward the data to V8. Internally, V8 will make a copy.
   obj->streaming_->OnBytesReceived(
       static_cast<const uint8_t*>(bytes) + offset, size);
+  obj->wasm_size_ += size;
 }
 
 void WasmStreamingObject::Finish(

src/node_wasm_web_api.h

@@ -16,7 +16,7 @@ class WasmStreamingObject final : public BaseObject {
 
   static void RegisterExternalReferences(ExternalReferenceRegistry* registry);
 
-  void MemoryInfo(MemoryTracker* tracker) const override {}
+  void MemoryInfo(MemoryTracker* tracker) const override;
   SET_MEMORY_INFO_NAME(WasmStreamingObject)
   SET_SELF_SIZE(WasmStreamingObject)
 
@@ -38,6 +38,7 @@ class WasmStreamingObject final : public BaseObject {
   static void Abort(const v8::FunctionCallbackInfo<v8::Value>& args);
 
   std::shared_ptr<v8::WasmStreaming> streaming_;
+  size_t wasm_size_;
 };
 
 // This is a v8::WasmStreamingCallback implementation that must be passed to