Calculator to determine the approximate memory space required for a hierarchical bitvector of a specified size

hibitset_mem_calc.rs

const COUNT: i32 = 500_000;
const BLOCK_SIZE: i32 = 1024;

fn main() {
    let mut count = COUNT;
    
    let mut block_count = 0;
    let mut layer_count = 1;
    while count > BLOCK_SIZE {
        let blocks = (count as f32 / (BLOCK_SIZE as f32)).ceil() as i32;
        block_count += blocks;
        
        count = blocks;
        layer_count += 1;
    }
    
    let size_in_kb = to_kb(block_count * BLOCK_SIZE);
    
    println!("Total Capacity: {}", block_count * BLOCK_SIZE);
    println!("Layer Count: {}", layer_count);
    println!("Block Count: {}", block_count);
    println!("Size: {:.2}Kb", size_in_kb);
}

fn to_kb(value: i32) -> f32 {
    (value as f32 / 8.0) / 1024.0
}