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wasm VS js，谁快？（七）重构

回顾

开始新内容前让我们先回忆下之前的内容，之前我们构造了一棵约30万个节点的树，测出来结果 wasm比js慢约4倍，比较反直觉，所以我们拆分成：

#[wasm_bindgen]
#[derive(Clone)]
pub struct Item {
    name: String,
    children: Vec<Item>,
}

#[wasm_bindgen]
pub fn unsafeTreeFun(treeLevel: u32, nodeWidth: u32) -> Item {
    let tempNode = Item {
        name: String::from(""),
        children: vec![],
    };

    let mut root = tempNode.clone();
    root.name = String::from("node_0_0");

    if treeLevel < 2 {
        return root;
    }

    let mut nodeStack: VecDeque<&mut Item> = VecDeque::new();

    for m1 in 0..nodeWidth {
        let mut curItem = tempNode.clone();
        curItem.name = format!("node_{}_{}", 1, m1);
        root.children.push(curItem);
    }

    let ptr1 = root.children.as_mut_ptr();
    unsafe {
        for m2 in 0..nodeWidth {
            nodeStack.push_back(&mut *ptr1.add(m2.try_into().unwrap()));
        }
    }

    for i in 2..treeLevel {
        let curTotal: u32 = nodeWidth.pow(i - 1);

        for j in 0..curTotal {
            let shiftItem = nodeStack.pop_front().unwrap();

            for k1 in 0..nodeWidth {
                let mut curItem = tempNode.clone();
                curItem.name = format!("node_{}_{}", i, nodeWidth * j + k1);
                shiftItem.children.push(curItem);
            }

            let ptr2 = shiftItem.children.as_mut_ptr();
            unsafe {
                for k2 in 0..nodeWidth {
                    nodeStack.push_back(&mut *ptr2.add(k2.try_into().unwrap()));
                }
            }
        }
    }

    root
}

total nodes:  299593
wasm-deq-tree: 347.54443359375 ms
js-tree: 7232.81201171875 ms