Reduce coupling in the unreal side

Source/Integration/StreamBuffer.h

@@ -0,0 +1,71 @@
+#pragma once
+
+#include "CoreMinimal.h"
+#include "lpx-basebuffer.hpp"
+
+class FlxStreamBufferConfig {
+private:
+	bool err_eof_on_read_;
+	bool err_string_too_long_;
+	bool err_integer_truncated_;
+public:
+    using string_type = std::string;
+    using fvector_type = FVector;
+    using dvector_type = FVector;
+    using luavalue_type = BaseLuaValue<std::string>;
+    void *basebuffer_malloc(size_t size) { return malloc(size); }
+    void basebuffer_free(void *p) { free(p); }
+    void clear_error_flags() { err_eof_on_read_ = err_string_too_long_ = err_integer_truncated_ = false; }
+	void raise_eof_on_read() { err_eof_on_read_ = true; }
+    void raise_string_too_long() { err_string_too_long_ = true; }
+	void raise_integer_truncated() { err_integer_truncated_ = true; }
+
+public:
+	bool get_err_eof_on_read() const { return err_eof_on_read_; }
+	bool get_err_string_too_long() const { return err_string_too_long_; }
+	bool get_err_integer_truncated() const { return err_integer_truncated_; }
+	bool any_error() const { return err_eof_on_read_ || err_string_too_long_ || err_integer_truncated_; }
+};
+
+class FlxStreamBuffer : public BaseBuffer<FlxStreamBufferConfig> {
+public:
+    using BaseBuffer::BaseBuffer;
+    using BaseBuffer::write_string;
+
+    void write_string(const FString &str) {
+	    FTCHARToUTF8 utf8str(str);
+        write_string(std::string_view(utf8str.Get(), utf8str.Length()));
+    }
+
+    void write_fname(const FName &name) {
+	    FTCHARToUTF8 utf8str(name.ToString());
+        write_string(std::string_view(utf8str.Get(), utf8str.Length()));
+    }
+
+    void write_string(const char *s) {
+        write_string(std::string_view(s));
+    }
+
+    void write_fvector(const FVector &xyz) {
+        write_double(xyz.X);
+        write_double(xyz.Y);
+        write_double(xyz.Z);
+    }
+
+    FVector read_fvector() {
+        double x = read_double();
+        double y = read_double();
+        double z = read_double();
+        return FVector(x, y, z);
+    }
+
+    FString read_fstring() {
+        std::string_view s = read_string_view();
+	    return FString(s.size(), (const UTF8CHAR *)s.data());
+    }
+
+    FName read_fname() {
+        std::string_view s = read_string_view();
+        return FName(s.size(), (const UTF8CHAR *)s.data(), FNAME_Add);
+    }
+};