struct Buffer {
    buffer: Vec<[u8; 4]>,
}

impl Buffer {
    pub fn receive_int32(&mut self, mut data: Vec<[u8; 4]>) -> Vec<[u8; 4]> {
        // Lock the mutex
        let current_data = &mut self.buffer;

        // If the sizes are not equal then we need to adjust the size of this buffer
        if data.len() != current_data.len() {
            data.reserve_exact(current_data.len() - data.len());
            data.resize(current_data.len(), [0u8; 4]);
        }

        // Copy the current data to the new buffer
        data.copy_from_slice(&current_data);

        // Swap the buffers and return the current buffer
        std::mem::replace(current_data, data)
    }
}

pub fn main() {
    let buffer1: Vec<[u8; 4]> = Vec::new();
    let mut buffer2: Vec<[u8; 4]> = Vec::new();

    buffer2.push([0,1,2,3]);

    let mut buffer = Buffer {
        buffer: buffer2,
    };

    println!("Initial Receive Buffer {:?}", &buffer.buffer);
    println!("Empty Swap Buffer {:?}", &buffer1);
    let new_buff1 = buffer.receive_int32(buffer1);
    println!("After First Receive {:?}", &new_buff1);
    let new_buff2 = buffer.receive_int32(new_buff1);
    println!("After Second Receive {:?}", &new_buff2);


}