TArray<FColor> backed by shared memory

Development Programming & Scripting C++
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1

Hello

I have the following code, it works well.

		TArray<FColor> PixelBuffer;
		RenderTargetResource->ReadPixels(PixelBuffer);

                // call a C API from .dll written in Rust.
		SendFrameFunc(PixelBuffer.GetData(), PixelBuffer.Num() * 4/*RGBA*/);

And in my Rust code, the pixels are copied into a shared memory region and send to another process.

pub unsafe extern "C" fn send_frame(frame: *const ffi::c_char, size: u32) -> i32 {
    // ...
    let mut region = MemoryRegion::new(size);
    let dest = match region.map(..).unwrap();
    let dest_ptr = std::ptr::addr_of_mut!(*dest);
    std::ptr::copy_nonoverlapping(frame, dest_ptr as *mut i8, size);
    message.memory_regions.push(region);
    //...
}

The above code works fine except it is low effecient. Each frame size is 8M bytes. The frame is read into PixelBuffer then copied into the memory region.

I want the ReadPixels method directly load pixels into shared memory to avoid copying.
I see TArray has a constructor TArray ( const ElementType* Ptr, SizeType Count ) accept the memory address. I think I can use it to construct a TArray backed by my memory region.

  1. I don’t need TArray free up my memory. Would it free up ElementType* Ptr on deconstruction? how can I avoid that? by implement my own Allocator?
  2. I will initialize TArray with the exact memory size as the pixels needs. So I assume reallocation would never occur?