uWebSockets.js/src/Utilities.h

#ifndef ADDON_UTILITIES_H
#define ADDON_UTILITIES_H

#include <v8.h>
using namespace v8;

class NativeString {
    char *data;
    size_t length;
    char utf8ValueMemory[sizeof(String::Utf8Value)];
    String::Utf8Value *utf8Value = nullptr;
    bool invalid = false;
public:
    NativeString(Isolate *isolate, const Local<Value> &value) {
        if (value->IsUndefined()) {
            data = nullptr;
            length = 0;
        } else if (value->IsString()) {
            utf8Value = new (utf8ValueMemory) String::Utf8Value(isolate, value);
            data = (**utf8Value);
            length = utf8Value->length();
        } else if (value->IsTypedArray()) {
            Local<ArrayBufferView> arrayBufferView = Local<ArrayBufferView>::Cast(value);
            ArrayBuffer::Contents contents = arrayBufferView->Buffer()->GetContents();
            length = contents.ByteLength();
            data = (char *) contents.Data();
        } else if (value->IsArrayBuffer()) {
            Local<ArrayBuffer> arrayBuffer = Local<ArrayBuffer>::Cast(value);
            ArrayBuffer::Contents contents = arrayBuffer->GetContents();
            length = contents.ByteLength();
            data = (char *) contents.Data();
        } else {
            invalid = true;
        }
    }

    bool isInvalid(const FunctionCallbackInfo<Value> &args) {
        if (invalid) {
            args.GetReturnValue().Set(isolate->ThrowException(String::NewFromUtf8(isolate, "Text and data can only be passed by String, ArrayBuffer or TypedArray.")));
        }
        return invalid;
    }

    std::string_view getString() {
        return {data, length};
    }

    ~NativeString() {
        if (utf8Value) {
            utf8Value->~Utf8Value();
        }
    }
};

#endif