src/main.rs

   1 use std::io::Cursor;
   2 use std::fmt::Display;
   3 use std::fmt;
   4 use actix_web::{get, web, App, HttpServer, HttpResponse, Responder, ResponseError, Result};
   5 use actix_web::body::BoxBody;
   6 use actix_web::http::StatusCode;
   7 use image::{ImageBuffer, ColorType, RgbImage, write_buffer_with_format};
   8 use image::ImageOutputFormat::Png;
   9
  10 #[derive(Debug)]
  11 struct ImageError(image::ImageError);
  12
  13 impl Display for ImageError {
  14     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  15         write!(f, "{}", &self.0)
  16     }
  17 }
  18
  19 impl ResponseError for ImageError {
  20     fn status_code(&self) -> StatusCode {
  21         StatusCode::INTERNAL_SERVER_ERROR
  22     }
  23
  24     fn error_response(&self) -> HttpResponse<BoxBody> {
  25         HttpResponse::InternalServerError().finish()
  26     }
  27 }
  28
  29 fn to_imageresult<T> (result: Result<T, image::ImageError>) -> Result<T, ImageError> {
  30     match result {
  31         Ok(v) => Ok(v),
  32         Err(e) => Err(ImageError(e))
  33     }
  34 }
  35
  36 #[get("/hello/{name}")]
  37 async fn greet(name: web::Path<String>) -> impl Responder {
  38     format!("Hello {name}!")
  39 }
  40
  41 #[get("/gen/{data}")]
  42 async fn img_gen(data: web::Path<String>) -> Result<impl Responder> {
  43     let mut cursor = Cursor::new(Vec::new());
  44     let mut img: RgbImage = ImageBuffer::new(128, 128);
  45     let mut pixels = img.pixels_mut();
  46
  47     for c in data.chars() {
  48         let mut p = pixels.next().unwrap();
  49         p.0 = [c as u8, 0, 0];
  50     }
  51
  52     to_imageresult(write_buffer_with_format(&mut cursor, &img, 128, 128, ColorType::Rgb8, Png))?;
  53     Ok(HttpResponse::build(StatusCode::OK)
  54        .content_type("image/png")
  55        .body(cursor.into_inner()))
  56 }
  57
  58 #[actix_web::main] // or #[tokio::main]
  59 async fn main() -> std::io::Result<()> {
  60     HttpServer::new(|| {
  61         App::new().service(greet).service(img_gen)
  62     })
  63     .bind(("127.0.0.1", 8080))?
  64     .run()
  65     .await
  66 }