Category: Rust

Post requestを受け取るにはactix-webを使う。
まず、受信のテストから。

use actix_web::{get, post, web, App, HttpResponse, HttpServer, Responder};

#[post("/handshake")]
async fn handshake(req_body: String)-> impl Responder {
    println!("{}", req_body);
    HttpResponse::Ok().body(req_body)

}

#[actix_web::main]
async fn main() -> std::io::Result<()> {
    HttpServer::new(||{
        App::new()
            .service(handshake)
    })
    .bind(("127.0.0.1", 8080))?
    .run()
    .await
}

postする
$ curl -X POST -d “{\”time\”:\”2024-12-25 22:53:36.824066840 UTC\”,\”sender\”:\”4bac6cb0f4ad6397752c3d73b88c5c86e3d88ac695118494a1732e2abd16c76acad3d6586c37c8db7e69c2f812f99275198936957d72c38d71981991123\”,\”receiver\”:\”4bac6cb0f4ad6397752c3d73b88c5c86e3d88ac695118494a1732e2abd16c76acad3d6586c37c8db7e69c2f812f99275198936957d72c38d71981991124\”,\”amount\”:10,\”signature\”:\”8000E340A55A517D0F27F3A63FBE39ED576BA491DFAC89B44654AB147EC66B206B054BAAF53E318EB2721DC892B4736630F400547989AE9F7C069034ECB4DF98\”}”

サーバ側
Finished `dev` profile [unoptimized + debuginfo] target(s) in 3.70s
Running `target/debug/hoge`
{“time”:”2024-12-25 22:53:36.824066840 UTC”,”sender”:”4bac6cb0f4ad6397752c3d73b88c5c86e3d88ac695118494a1732e2abd16c76acad3d6586c37c8db7e69c2f812f99275198936957d72c38d71981991123″,”receiver”:”4bac6cb0f4ad6397752c3d73b88c5c86e3d88ac695118494a1732e2abd16c76acad3d6586c37c8db7e69c2f812f99275198936957d72c38d71981991124″,”amount”:10,”signature”:”8000E340A55A517D0F27F3A63FBE39ED576BA491DFAC89B44654AB147EC66B206B054BAAF53E318EB2721DC892B4736630F400547989AE9F7C069034ECB4DF98″}

受信できてます。
ここで受け取ったデータからverifyすればOKですね。

use serde::{Serialize, Deserialize};

#[derive(Debug, Serialize, Deserialize)]
struct SignedTransaction {
    time: String,
    sender: String,
    receiver: String,
    amount: i32,
    signature: String,
}

#[post("/handshake")]
async fn handshake(req_body: String)-> impl Responder {
    let req : SignedTransaction = serde_json::from_str(&req_body).unwrap();;
    println!("{}", req.signature);
    HttpResponse::Ok().body(req_body)

}

Postされたデータはjsonにして、SignedTransactionの構造体で受け取ると、req.signatureというように、値を取り出すことができる。

まずcargo newでプロジェクトを作成し、dependenciesにactixを追加します。

[dependencies]
actix-web = "4"

use actix_web::{get, post, web, App, HttpResponse, HttpServer, Responder};

#[get("/")]
async fn hello() -> impl Responder {
    HttpResponse::Ok().body("Hello world!")
}

#[post("/echo")]
async fn echo(req_body: String) -> impl Responder {
    HttpResponse::Ok().body(req_body)
}

async fn manual_hello() -> impl Responder {
    HttpResponse::Ok().body("Hey there!")
}

#[actix_web::main]
async fn main() -> std::io::Result<()> {
    HttpServer::new(||{
        App::new()
            .service(hello)
            .service(echo)
            .route("/hey", web::get().to(manual_hello))
    })
    .bind(("127.0.0.1", 8080))?
    .run()
    .await
}

$ curl -X POST -d “age=30” 127.0.0.1:8080/echo
age=30

おおおおおおお、get, postまではできたな…

use serde::{Deserialize, Serialize};

#[async_std::main]
async fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static>> {

    #[derive(Deserialize, Serialize)]
    struct Ip {
        ip: String,
    }

    let uri = "https://httpbin.org/post";
    let data = &Ip {
        ip: "129.0.0.1".into(),
    };
    let mut res = surf::post(uri).body_json(data)?.await?;
    let body = res.body_string().await?;
    println!("{}", body);

    let uri = "https://api.ipify.org?format=json";
    let Ip { ip } = surf::get(uri).recv_json().await?;
    println!("{}", ip);
    assert!(ip.len() > 10);
    Ok(())
}

Postができる。actix-webでpostされたデータを受け取ることができるかは要確認。

まずはGetリクエストから

use async_std::task;

fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static>> {
    task::block_on(async {
        let mut res = surf::get("https://httpbin.org/get").await?;
        dbg!(res.body_string().await?);
        Ok(())
    })
}

#[async_std::main]
async fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static>> {
    let mut res = surf::get("https://httpbin.org/get").await?;
    dbg!(res.body_string().await?);
    Ok(())
}

[src/main.rs:4:5] res.body_string().await? = “{\n \”args\”: {}, \n \”headers\”: {\n \”Accept\”: \”*/*\”, \n \”Accept-Encoding\”: \”deflate, gzip\”, \n \”Host\”: \”httpbin.org\”, \n \”User-Agent\”: \”curl/8.11.0-DEV isahc/0.7.6\”, \n \”X-Amzn-Trace-Id\”: \”Root=1-676a57b7-3de7e4ff65be3baf597f36f8\”\n }, \n \”origin\”: \”106.155.3.182\”, \n \”url\”: \”https://httpbin.org/get\”\n}\n”

### actix-web
$ cargo new my_web_app
$ cd my_web_app

[dependencies]
actix-web = "4"

main.rs

use actix_web::{web, App, HttpResponse, HttpServer, Responder};

async fn greet() -> impl Responder {
    HttpResponse::Ok().body("Hello, world!")
}

#[actix_web::main]
async fn main() -> std::io::Result<()> {
    HttpServer::new(||{
        App::new()
            .route("/", web::get().to(greet))
    })
    .bind("127.0.0.1:8080")?
    .run()
    .await
}

$ curl 127.0.0.1:8080
Hello, world!

ほう

### Rocket
$ cargo new rocket_web_app
$ cd rocket_web_app
$ rustup override set nightly

#[macro_use] extern crate rocket;

#[get("/")]
fn index() -> &'static str {
    "Hello, world!"
}

#[launch]
fn rocket() -> _ {
    rocket::build().mount("/", routes![index])
}

$ cargo run
Compiling rocket_web_app v0.1.0 (/home/vagrant/dev/rust/rocket_web_app)
error[E0463]: can’t find crate for `rocket`
–> src/main.rs:1:14
|
1 | #[macro_use] extern crate rocket;
| ^^^^^^^^^^^^^^^^^^^^ can’t find crate
….

rocketの方は色々エラーが出るので、少し触った感じではactix-webの方が使いやすそう..

遅いリクエストを実装

use std::thread;
use std::time::Duration;

// 

    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")
    };

### スレッドプール
タスクを処理する準備のできた一塊の大量に生成されたスレッド
ただし、固定された数のスレッドにすることで、無制限に大量生産してDos攻撃の被害に遭うことを抑える。

fn main() {
    let listner = TcpListener::bind("127.0.0.1:7878").unwrap();

    for stream in listner.incoming() {
        let stream = stream.unwrap();

        thread::spawn(||{
            handle_connection(stream);
        });
    }
}

スレッド数を限定する

use std::thread;

pub struct ThreadPool {
    workers: Vec<Worker>,
}

impl ThreadPool {
    pub fn new(size: usize) -> ThreadPool {
        assert!(size > 0);

        let mut threads = Vec::with_capacity(size);

        for _ in 0..size {
            workers.push(Worker::new(id));
        }
        ThreadPool {
            workers
        }
    }

    pub fn execute<F>(&self, f: F)
        where
            F: FnOnce() + Send + 'static
    {

    }
}

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

impl Worker {
    fn new(id: usize) -> Worker {
        let thread = thread::spawn(||{});

        Worker {
            id,
            thread,
        }
    }
}

use std::thread;
use std::sync::mpsc;
use std::sync::Arc;
use std::sync::Mutex;

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

trait FnBox {
    fn call_box(self: Box<Self>);
}

impl<F: FnOnce()> FnBox for F {
    fn call_box(self: Box<F>){
        (*self)()
    }
}

type Job = Box<dyn FnBox + Send + 'static>;


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(job).unwrap();
    }
}

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

impl Worker {
    fn new(id: usize, receiver: Arc<Mutex<mpsc::Receiver<Job>>>) -> Worker {
        let thread = thread::spawn(move||{
            loop {
                let job = receiver.lock().unwrap().recv().unwrap();

                println!("Worker {} got a job; executing.", id);
                job.call_box();
            }
        });

        Worker {
            id,
            thread,
        }
    }
}

Worker 0 got a job; executing.
Worker 1 got a job; executing.
Worker 2 got a job; executing.
Worker 3 got a job; executing.
Worker 0 got a job; executing.

unwrap()は、OptionがSomeの場合はその中の値を返し、Noneの場合はパニックを引き起こす。

fn main(){
    let value = Some(10);
    let v = value.unwrap();
    println!("v: {}", v);
}

Rustの「unwrap」と「?」はエラーハンドリングに使われる方法
unwrapはOption型やResult型の値がSomeやOkであることを前提として値を取り出す。NoneやErrだった場合は、panic!マクロが呼ばれてプログラムがクラッシュする。
?演算子は、Okの場合は値を返し、Errの場合はそのErrを呼び出し元に返す。

なるほど、OptionとResultがわかってないと、unwrapと?もさっぱり理解できませんね。。

Resultは、失敗するかもしれない処理の結果を表現する列挙型。

enum Result<T, E>{
    Ok(T),
    Err(E),
}

fn get_value_bad(v: bool, result: &mut usize) -> usize {
    if v {
        *result = 100;
        true
    } else {
        false
    }
}

fn get_value_good(v: bool) -> Result<usize, &'static str> {
    if v {
        OK(100)
    } else {
        Err("error message")
    }
}

fn main(){
    let mut result = 0;
    if get_value_bad(true, &mut result){
        println!("success: {}", result);
    } else {
        println!("failure");
    }

    match get_value_good(true){
        Ok(result) => println!("success: {}", result),
        Err(msg) => println!("failure")
    }
}

fn plus_one(x: Option<i32>) -> Option<i32> {
    match x {
        None => None,
        Some(i) => Some(i + 1),
    }
}

fn main(){
    let five = Some(5);
    let six = plus_one(five);
    let none = plus_one(None);
}

use std::fs::File;

fn main(){
    let f = File::open("hello.txt");

    let _f = match f {
        Ok(file) => file,
        Err(error) => {
            panic!("There was a problem opening the file: {:?}", error);
        }
    };
}

OptionはSome, None, ResultはOk, Errで共にエラーハンドリングなどで使うのね。