rust一个简易WebServer的例子

构建简易多线程web服务器：

• 在socket上监听TCP连接
• 解析少量HTTP请求
• 创建合适的HTTP响应
• 使用线程池改进服务器的吞吐量

lib.rs

use std::{thread, sync::{mpsc::{self, Receiver}, Mutex, Arc}};

struct Worker {
    id: usize,
    thread: Option<thread::JoinHandle<()>>,
}

enum Message {
    NewJob(Job),
    Terminate
}

pub struct ThreadPool {
    workers: Vec<Worker>,
    sender: mpsc::Sender<Message>,
}

// struct  Job;
type Job = Box<dyn FnOnce() + Send + 'static>;

impl Worker {
    fn new(id: usize, receiver: Arc<Mutex<Receiver<Message>>>) -> Worker {
        let thread = thread::spawn(move || loop {
            let message = receiver.lock().unwrap().recv().unwrap();
            match message {
                Message::NewJob(job) => {
                    println!("Worker {} got a job, executing", id);
                    job();
                }
                Message::Terminate => {
                    println!("Worker {} done!", id);
                    break;
                }
            };
            
        });
        Worker { id, thread: Some(thread) }
    }
}

impl ThreadPool {
    pub fn new(size: usize) -> ThreadPool {
        assert!(size > 0);
        let (sender, receiver) = mpsc::channel();
        
        let receiver = Arc::new(Mutex::new(receiver));
        let mut workers = Vec::with_capacity(size);

        for id in 0..size {
            workers.push(Worker::new(id, Arc::clone(&receiver)));
        }
        ThreadPool {workers, sender}
    }

    pub fn execute<F>(&self, f:F)
    where
        F: FnOnce() + Send + 'static
    {
        let job = Box::new(f);
        self.sender.send(Message::NewJob(job)).unwrap();
    }

}


// 优雅地关闭
impl Drop for ThreadPool {
    fn drop(&mut self) {
        for worker in &mut self.workers {
            self.sender.send(Message::Terminate);
        }
        for worker in &mut self.workers {
            if let Some(thread) = worker.thread.take() {
                thread.join().unwrap();
            }
            
        }
    }
}

main.rs

use std::{net::{TcpListener, TcpStream}, io::{Read, Write}, fs, thread, time::Duration};
use webserver::ThreadPool;

fn main() {
    let listener = TcpListener::bind("127.0.0.1:8080").unwrap();
    let pool = ThreadPool::new(4);

    for stream in listener.incoming().take(2) {
        let stream = stream.unwrap();
        pool.execute(||{
            handle_connection(stream);
        });
        
    }
}

fn handle_connection(mut stream: TcpStream) {
    let mut buffer = [0;512];
    stream.read(&mut buffer).unwrap();

    let get = b"GET / HTTP/1.1\r\n";
    let sleep = b"GET /sleep HTTP/1.1\r\n";


    let (status_line, filename) = if buffer.starts_with(get) {
        ("HTTP/1.1 200 OK\r\n\r\n", "hello.html")
    } else if buffer.starts_with(sleep){
        thread::sleep(Duration::from_secs(5));
        ("HTTP/1.1 200 OK\r\n\r\n", "hello.html")
    } else {
        ("HTTP/1.1 404 NOT FOUND\r\n\r\n", "404.html")
    };
    let contents = fs::read_to_string(filename).unwrap();
    // println!("Request: {}",String::from_utf8_lossy(&buffer[..]));
    let response = format!("{}{}", status_line ,contents);
    //println!("{}",response);
    stream.write(response.as_bytes()).unwrap();
    stream.flush().unwrap();
}