러스트로 작성된 브리지

브리지는 구조 디자인 패턴입니다. 이 패턴은 비즈니스 로직 또는 거대한 클래스를 독립적으로 개발할 수 있는 별도의 클래스 계층구조들로 나눕니다.

종종 추상화라고 불리는 이러한 계층구조 중 하나는 두 번째 계층구조의 객체(구현)에 대한 참조를 얻습니다. 추상화의 호출들 일부(때로는 대부분)를 구현 객체에 위임할 수 있습니다. 모든 구현은 공통 인터페이스를 가지므로 추상화 내에서 상호 교환할 수 있습니다.

브리지에 대하여 더 자세히 알아보세요

내비게이션

소개

Devices and Remotes

mod

basic

advanced

mod

radio

main

Devices and Remotes

This example illustrates how the Bridge pattern can help divide the monolithic code of an app that manages devices and their remote controls. The Device classes act as the implementation, whereas the Remotes act as the abstraction.

remotes/mod.rs

mod advanced;
mod basic;

pub use advanced::AdvancedRemote;
pub use basic::BasicRemote;

use crate::device::Device;

pub trait HasMutableDevice<D: Device> {
    fn device(&mut self) -> &mut D;
}

pub trait Remote<D: Device>: HasMutableDevice<D> {
    fn power(&mut self) {
        println!("Remote: power toggle");
        if self.device().is_enabled() {
            self.device().disable();
        } else {
            self.device().enable();
        }
    }

    fn volume_down(&mut self) {
        println!("Remote: volume down");
        let volume = self.device().volume();
        self.device().set_volume(volume - 10);
    }

    fn volume_up(&mut self) {
        println!("Remote: volume up");
        let volume = self.device().volume();
        self.device().set_volume(volume + 10);
    }

    fn channel_down(&mut self) {
        println!("Remote: channel down");
        let channel = self.device().channel();
        self.device().set_channel(channel - 1);
    }

    fn channel_up(&mut self) {
        println!("Remote: channel up");
        let channel = self.device().channel();
        self.device().set_channel(channel + 1);
    }
}

remotes/basic.rs

use crate::device::Device;

use super::{HasMutableDevice, Remote};

pub struct BasicRemote<D: Device> {
    device: D,
}

impl<D: Device> BasicRemote<D> {
    pub fn new(device: D) -> Self {
        Self { device }
    }
}

impl<D: Device> HasMutableDevice<D> for BasicRemote<D> {
    fn device(&mut self) -> &mut D {
        &mut self.device
    }
}

impl<D: Device> Remote<D> for BasicRemote<D> {}

remotes/advanced.rs

use crate::device::Device;

use super::{HasMutableDevice, Remote};

pub struct AdvancedRemote<D: Device> {
    device: D,
}

impl<D: Device> AdvancedRemote<D> {
    pub fn new(device: D) -> Self {
        Self { device }
    }

    pub fn mute(&mut self) {
        println!("Remote: mute");
        self.device.set_volume(0);
    }
}

impl<D: Device> HasMutableDevice<D> for AdvancedRemote<D> {
    fn device(&mut self) -> &mut D {
        &mut self.device
    }
}

impl<D: Device> Remote<D> for AdvancedRemote<D> {}

device/mod.rs

mod radio;
mod tv;

pub use radio::Radio;
pub use tv::Tv;

pub trait Device {
    fn is_enabled(&self) -> bool;
    fn enable(&mut self);
    fn disable(&mut self);
    fn volume(&self) -> u8;
    fn set_volume(&mut self, percent: u8);
    fn channel(&self) -> u16;
    fn set_channel(&mut self, channel: u16);
    fn print_status(&self);
}

device/radio.rs

use super::Device;

#[derive(Clone)]
pub struct Radio {
    on: bool,
    volume: u8,
    channel: u16,
}

impl Default for Radio {
    fn default() -> Self {
        Self {
            on: false,
            volume: 30,
            channel: 1,
        }
    }
}

impl Device for Radio {
    fn is_enabled(&self) -> bool {
        self.on
    }

    fn enable(&mut self) {
        self.on = true;
    }

    fn disable(&mut self) {
        self.on = false;
    }

    fn volume(&self) -> u8 {
        self.volume
    }

    fn set_volume(&mut self, percent: u8) {
        self.volume = std::cmp::min(percent, 100);
    }

    fn channel(&self) -> u16 {
        self.channel
    }

    fn set_channel(&mut self, channel: u16) {
        self.channel = channel;
    }

    fn print_status(&self) {
        println!("------------------------------------");
        println!("| I'm radio.");
        println!("| I'm {}", if self.on { "enabled" } else { "disabled" });
        println!("| Current volume is {}%", self.volume);
        println!("| Current channel is {}", self.channel);
        println!("------------------------------------\n");
    }
}

device/tv.rs

use super::Device;

#[derive(Clone)]
pub struct Tv {
    on: bool,
    volume: u8,
    channel: u16,
}

impl Default for Tv {
    fn default() -> Self {
        Self {
            on: false,
            volume: 30,
            channel: 1,
        }
    }
}

impl Device for Tv {
    fn is_enabled(&self) -> bool {
        self.on
    }

    fn enable(&mut self) {
        self.on = true;
    }

    fn disable(&mut self) {
        self.on = false;
    }

    fn volume(&self) -> u8 {
        self.volume
    }

    fn set_volume(&mut self, percent: u8) {
        self.volume = std::cmp::min(percent, 100);
    }

    fn channel(&self) -> u16 {
        self.channel
    }

    fn set_channel(&mut self, channel: u16) {
        self.channel = channel;
    }

    fn print_status(&self) {
        println!("------------------------------------");
        println!("| I'm TV set.");
        println!("| I'm {}", if self.on { "enabled" } else { "disabled" });
        println!("| Current volume is {}%", self.volume);
        println!("| Current channel is {}", self.channel);
        println!("------------------------------------\n");
    }
}

main.rs

mod device;
mod remotes;

use device::{Device, Radio, Tv};
use remotes::{AdvancedRemote, BasicRemote, HasMutableDevice, Remote};

fn main() {
    test_device(Tv::default());
    test_device(Radio::default());
}

fn test_device(device: impl Device + Clone) {
    println!("Tests with basic remote.");
    let mut basic_remote = BasicRemote::new(device.clone());
    basic_remote.power();
    basic_remote.device().print_status();

    println!("Tests with advanced remote.");
    let mut advanced_remote = AdvancedRemote::new(device);
    advanced_remote.power();
    advanced_remote.mute();
    advanced_remote.device().print_status();
}

Output

Tests with basic remote.
Remote: power toggle
------------------------------------
| I'm TV set.
| I'm enabled
| Current volume is 30%
| Current channel is 1
------------------------------------

Tests with advanced remote.
Remote: power toggle
Remote: mute
------------------------------------
| I'm TV set.
| I'm enabled
| Current volume is 0%
| Current channel is 1
------------------------------------

Tests with basic remote.
Remote: power toggle
------------------------------------
| I'm radio.
| I'm enabled
| Current volume is 30%
| Current channel is 1
------------------------------------

Tests with advanced remote.
Remote: power toggle
Remote: mute
------------------------------------
| I'm radio.
| I'm enabled
| Current volume is 0%
| Current channel is 1
------------------------------------```