0019-wasm-康威生命游戏

环境

• Time 2022-05-17
• Rust 1.60.0
• Node 12.22.5
• wasm-pack 0.10.2

前言

说明

参考：https://rustwasm.github.io/docs/book/game-of-life/debugging.html

目标

在上一节的基础上进行。对 wasm_bindgen 进行调试。包括以下两方面：

1. 直接在 Rust 中向浏览器控制台输出日志。
2. 发生 panic 后，能在浏览器中找到 Rust 中对应的文件和行数。

引入依赖

打印日志需要 web-sys 依赖，并启用 console 特性。

web-sys = {version = "*", features = ["console"]}

定义日志宏

macro_rules! log {
    ( $( $t:tt )* ) => {
        web_sys::console::log_1(&format!( $( $t )* ).into());
    }
}

记录日志

pub fn new(width: u32, height: u32) -> Universe {
    log!("new universe, width: {}, height: {}", width, height);
    let size = (width * height) as usize;
    let mut cells = FixedBitSet::with_capacity(size);
    (0..size).for_each(|i| cells.set(i, Math::random() < 0.5));

    Universe {
        width,
        height,
        cells,
    }
}

日志效果

增加 panic

    pub fn new(width: u32, height: u32) -> Universe {
        // #[cfg(feature = "console_error_panic_hook")]
        // console_error_panic_hook::set_once();

        log!("new universe, width: {}, height: {}", width, height);
        let size = (width * height) as usize;
        let mut cells = FixedBitSet::with_capacity(size);
        (0..size).for_each(|i| cells.set(i, Math::random() < 0.5));

        Universe {
            width,
            height,
            cells,
        };
        panic!("this is my panic");
    }

异常信息

在浏览器中看不到异常信息是什么，出在什么地方。

打开 panic_hook

将注释掉的 panic_hook 打开。

    pub fn new(width: u32, height: u32) -> Universe {
        #[cfg(feature = "console_error_panic_hook")]
        console_error_panic_hook::set_once();

        log!("new universe, width: {}, height: {}", width, height);
        let size = (width * height) as usize;
        let mut cells = FixedBitSet::with_capacity(size);
        (0..size).for_each(|i| cells.set(i, Math::random() < 0.5));

        Universe {
            width,
            height,
            cells,
        };
        panic!("this is my panic");
    }

debug 构建

C:\Users\jiangbo\workspace\rust\game>wasm-pack build --debug
[INFO]: Checking for the Wasm target...
[INFO]: Compiling to Wasm...
   Compiling game v0.1.0 (C:\Users\jiangbo\workspace\rust\game)
    Finished dev [unoptimized + debuginfo] target(s) in 0.94s
[WARN]: :-) origin crate has no README
[INFO]: Installing wasm-bindgen...
[INFO]: Optional fields missing from Cargo.toml: 'description', 'repository', and 'license'. These are not necessary, but recommended
[INFO]: :-) Done in 1.87s
[INFO]: :-) Your wasm pkg is ready to publish at C:\Users\jiangbo\workspace\rust\game\pkg.

错误详细信息

总结

对康威生命游戏进行调试，包括打印浏览器日志信息和追踪调用栈信息。

附录