feat: Faster loading of JS files (#73)

* feat: Increase speed of loading JS files

Author: Nathanael Anderson

NativeScript/runtime/Helpers.h

@@ -23,6 +23,7 @@ bool ToBool(const v8::Local<v8::Value>& value);
 std::vector<uint16_t> ToVector(const std::string& value);
 
 bool Exists(const char* fullPath);
+v8::Local<v8::String> ReadModule(v8::Isolate* isolate, const std::string &filePath);
 const char* ReadText(const std::string& filePath, long& length, bool& isNew);
 std::string ReadText(const std::string& file);
 uint8_t* ReadBinary(const std::string path, long& length, bool& isNew);

NativeScript/runtime/Helpers.mm

@@ -113,6 +113,38 @@
     return false;
 }
 
+Local<v8::String> tns::ReadModule(Isolate* isolate, const std::string &filePath) {
+    struct stat finfo;
+
+    int file = open(filePath.c_str(), O_RDONLY);
+    if (file < 0) {
+        tns::Assert(false);
+    }
+
+    fstat(file, &finfo);
+    long length = finfo.st_size;
+
+    char* newBuffer = new char[length + 128];
+    strcpy(newBuffer, "(function(module, exports, require, __filename, __dirname) { ");  // 61 Characters
+    read(file, &newBuffer[61], length);
+    close(file);
+    length += 61;
+
+    // Add the closing "\n})"
+    newBuffer[length] = 10;
+    ++length;
+    newBuffer[length] = '}';
+    ++length;
+    newBuffer[length] = ')';
+    ++length;
+    newBuffer[length] = 0;
+
+    Local<v8::String> str = v8::String::NewFromUtf8(isolate, newBuffer, NewStringType::kNormal, (int)length).ToLocalChecked();
+    delete[] newBuffer;
+
+    return str;
+}
+
 const char* tns::ReadText(const std::string& filePath, long& length, bool& isNew) {
     FILE* file = fopen(filePath.c_str(), "rb");
     if (file == nullptr) {

NativeScript/runtime/ModuleInternal.mm

@@ -283,12 +283,7 @@
 }
 
 Local<v8::String> ModuleInternal::WrapModuleContent(Isolate* isolate, const std::string& path) {
-    std::string content = tns::ReadText(path);
-    std::string result("(function(module, exports, require, __filename, __dirname) { ");
-    result.reserve(content.length() + 1024);
-    result += content;
-    result += "\n})";
-    return tns::ToV8String(isolate, result);
+    return tns::ReadModule(isolate, path);
 }
 
 std::string ModuleInternal::ResolvePath(Isolate* isolate, const std::string& baseDir, const std::string& moduleName) {