Blob: Add factory function (#120)

- Add `CreateInstance` for other Native code to bypass copy in Blob
constructor

Author: alexchuber

Polyfills/Blob/Include/Babylon/Polyfills/Blob.h

@@ -1,9 +1,17 @@
 #pragma once
 
 #include <napi/env.h>
+#include <napi/napi.h>
 #include <Babylon/Api.h>
+#include <vector>
+#include <string>
 
 namespace Babylon::Polyfills::Blob
 {
     void BABYLON_API Initialize(Napi::Env env);
+
+    Napi::Value BABYLON_API CreateInstance(
+        Napi::Env env,
+        std::vector<std::byte> data,
+        std::string type);
 }

Polyfills/Blob/Source/Blob.cpp

@@ -4,9 +4,10 @@
 
 namespace Babylon::Polyfills::Internal
 {
+    static constexpr auto JS_BLOB_CONSTRUCTOR_NAME = "Blob";
+
     void Blob::Initialize(Napi::Env env)
     {
-        static constexpr auto JS_BLOB_CONSTRUCTOR_NAME = "Blob";
         if (env.Global().Get(JS_BLOB_CONSTRUCTOR_NAME).IsUndefined())
         {
             Napi::Function func = DefineClass(
@@ -17,13 +18,30 @@ namespace Babylon::Polyfills::Internal
                     InstanceAccessor("type", &Blob::GetType, nullptr),
                     InstanceMethod("text", &Blob::Text),
                     InstanceMethod("arrayBuffer", &Blob::ArrayBuffer),
-                    InstanceMethod("bytes", &Blob::Bytes)
+                    InstanceMethod("bytes", &Blob::Bytes),
                 });
 
             env.Global().Set(JS_BLOB_CONSTRUCTOR_NAME, func);
         }
     }
 
+    Napi::Value Blob::CreateInstance(
+        Napi::Env env,
+        std::vector<std::byte> data,
+        std::string type)
+    {
+        Initialize(env);
+
+        auto ctor{env.Global().Get(JS_BLOB_CONSTRUCTOR_NAME).As<Napi::Function>()};
+        auto jsBlob{ctor.New({})};
+
+        auto blob{Blob::Unwrap(jsBlob)};
+        blob->m_data = std::move(data);
+        blob->m_type = std::move(type);
+
+        return jsBlob;
+    }
+
     Blob::Blob(const Napi::CallbackInfo& info)
         : Napi::ObjectWrap<Blob>(info)
     {
@@ -133,4 +151,12 @@ namespace Babylon::Polyfills::Blob
     {
         Internal::Blob::Initialize(env);
     }
+
+    Napi::Value BABYLON_API CreateInstance(
+        Napi::Env env,
+        std::vector<std::byte> data,
+        std::string type)
+    {
+        return Internal::Blob::CreateInstance(env, std::move(data), std::move(type));
+    }
 }

Polyfills/Blob/Source/Blob.h

@@ -12,6 +12,11 @@ namespace Babylon::Polyfills::Internal
     public:
         static void Initialize(Napi::Env env);
 
+        static Napi::Value CreateInstance(
+            Napi::Env env,
+            std::vector<std::byte> data,
+            std::string type);
+
         explicit Blob(const Napi::CallbackInfo& info);
 
     private: