Question

我正在学习Rust几天，说实话，有些概念真的很难理解和应用。我开始重写一小部分组件，以比较Rust的传奇速度并通过一个具体项目学习。它是测量时间并在执行期间监视程序的组件。这将是另一个程序使用的动态库。

我的问题：

1）如何从＆mut self创建Option<Box<T>>？（fn add_son）

extern crate winapi;
extern crate user32;
extern crate kernel32;


struct KpiMethod{
    element : String,
    line : u32,
    nb_occ : u32,
    counter_start : i64,
    counter_end : i64,
    total_time: i64,
    kpi_fils : Vec<KpiMethod>,
    kpi_father : Option<Box<KpiMethod>>
}

impl KpiMethod {

    pub fn new(_element: String, _line: u32, _father: Option<Box<KpiMethod>>) -> KpiMethod {
        KpiMethod{
            element : _element,
            line : _line,
            nb_occ : 1,
            counter_start : get_counter(),
            counter_end : 0,
            total_time: 0,
            kpi_fils : Vec::new(),
            kpi_father : _father
        }
    }

    pub fn add_son(&mut self, _element: String, _line: u32) -> KpiMethod{
        //How create a Option<Box<KpiMethod>> of an existing KpiMethod (self) ?
        let mut kpimet = KpiMethod::new(_element, _line, Some(Box::new(self)));
        //Do I need a mutable self to push ?
        self.kpi_fils.push(kpimet);
        kpimet
    }

    pub fn find_son(&mut self, _element: String, _line: u32) -> Option<&KpiMethod> {

        //which is the good and speed method to find a son with key (element,line) ?
        for elem in self.kpi_fils.iter_mut() {
            if elem.element == _element && elem.line == _line {
                //why do I put a return here to fix error ?
                return Some(elem)
            }
        }

        None
    }

}

pub struct KpiAgent{
    kpi_Method : Vec<KpiMethod>,
    current_Method : Option<Box<KpiMethod>>,
    counter_start : i64,
    counter_end : i64,
    date_start : String,
    date_end : String,
    auto_consommation : u64,

}

impl KpiAgent {

    pub fn new() -> KpiAgent {
        KpiAgent{
            kpi_Method: Vec::new(),
            current_Method: None,
            counter_start: 0,
            counter_end: 0,
            date_start: String::from(""),
            date_end: String::from(""),
            auto_consommation: 0
        }
    }

    pub fn method_start(&mut self, element: String, line: u32){

        match self.current_Method {
            None => {
                self.current_Method = Some(Box::new(KpiMethod::new(element, line, None)));
                if self.counter_start == 0 {
                    self.counter_start = get_counter();
                }
            },
            Some(method) => {
                let metfils = method.find_son(element, line);
                match metfils {
                    None => {
                        self.current_Method = Some(Box::new(method.add_son(element, line)));
                    },
                    Some(son) => {
                        son.nb_occ += 1;
                        son.counter_start = get_counter();
                    }
                }
            },
        }
    }

    pub fn method_end(&mut self, element: String, line: u32){
        match self.current_Method{
            Some(met) => {
                met.counter_end = get_counter();
                self.counter_end = met.counter_end;
                met.total_time += met.counter_end - met.counter_start;
                self.current_Method = met.kpi_father; 
            }
        }
    }
}

pub fn get_counter() -> i64 {
    let mut counter: i64 = 0;
    unsafe{
        kernel32::QueryPerformanceCounter(&mut counter);
    }
    counter
}


pub fn main() {

    let mut met = KpiMethod::new("1c".to_string(), 1, None);
    met.add_son("2c".to_string(),2);
    met.add_son("3c".to_string(),3);
    met.add_son("4c".to_string(),4);
    let _toto = met.find_son("3c".to_string(),3);
    match _toto{
        None => println!("Not found"),
        Some(x) => println!("{}",x.element),
    }

    let mut agent = KpiAgent::new();
    agent.method_start("test".to_string(),2);
    agent.method_end("test".to_string(),10);

}

Rust的第一步，如何从＆mut self创建一个Option <Box <T >>？

0 个答案: