src/main.rs

   1 use std::io::Cursor;
   2 use std::fmt::Display;
   3 use std::fmt;
   4 use std::borrow::BorrowMut;
   5 use num_traits::Zero;
   6 use num_traits::cast::AsPrimitive;
   7 use percent_encoding::percent_decode_str;
   8 use actix_web::{get, web, App, HttpServer, HttpRequest, HttpResponse, Responder, ResponseError, Result};
   9 use actix_web::body::BoxBody;
  10 use actix_web::http::StatusCode;
  11 use image::{ImageBuffer, ColorType, Pixel, Rgb, RgbImage, write_buffer_with_format};
  12 use image::ImageOutputFormat::Png;
  13 use image::imageops::{FilterType, resize};
  14
  15
  16 #[derive(Debug)]
  17 struct ImageError(image::ImageError);
  18
  19 impl Display for ImageError {
  20     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  21         write!(f, "{}", &self.0)
  22     }
  23 }
  24
  25 impl ResponseError for ImageError {
  26     fn status_code(&self) -> StatusCode {
  27         StatusCode::INTERNAL_SERVER_ERROR
  28     }
  29
  30     fn error_response(&self) -> HttpResponse<BoxBody> {
  31         HttpResponse::InternalServerError().finish()
  32     }
  33 }
  34
  35 struct ToRgbIter<'a, T> where T: AsPrimitive<u8> {
  36     iter: Box<&'a mut dyn Iterator<Item = T>>
  37 }
  38
  39 impl<'a, T: AsPrimitive<u8>> ToRgbIter<'a, T> {
  40     fn new(data: &'a mut (dyn Iterator<Item = T>)) -> ToRgbIter<T> {
  41         ToRgbIter { iter: Box::new(data) }
  42     }
  43 }
  44
  45 impl<T: AsPrimitive<u8> + Zero> Iterator for ToRgbIter<'_, T> {
  46     type Item = Rgb<u8>;
  47     fn next(&mut self) -> Option<Rgb<u8>> {
  48         if let Some(r) = self.iter.next() {
  49             let g = self.iter.next().unwrap_or(T::zero());
  50             let b = self.iter.next().unwrap_or(T::zero());
  51             Some(Rgb([r.as_(), g.as_(), b.as_()]))
  52         }
  53         else {
  54             None
  55         }
  56     }
  57 }
  58
  59 fn to_imageresult<T> (result: Result<T, image::ImageError>) -> Result<T, ImageError> {
  60     match result {
  61         Ok(v) => Ok(v),
  62         Err(e) => Err(ImageError(e))
  63     }
  64 }
  65
  66 #[get("/hello/{name}")]
  67 async fn greet(name: web::Path<String>, req: HttpRequest) -> impl Responder {
  68     println!("{:?}", req);
  69     format!("Hello {name}!")
  70 }
  71
  72 fn make_png(dim_x: u32, dim_y: u32, scale: u32, data: &mut dyn Iterator<Item = u8>) -> Result<Cursor<Vec<u8>>, ImageError> {
  73     let mut img: RgbImage = ImageBuffer::new(dim_x, dim_y);
  74     let mut pixels = img.pixels_mut();
  75
  76     for sp in ToRgbIter::new(data) {
  77         let mut dp = pixels.next().unwrap();
  78         println!("{:?}", sp);
  79         dp.0 = sp.0;
  80     }
  81
  82     let tdim_x = dim_x * scale;
  83     let tdim_y = dim_y * scale;
  84     let img = resize(&img, tdim_x, tdim_y, FilterType::Nearest);
  85     let mut cursor = Cursor::new(Vec::new());
  86     to_imageresult(write_buffer_with_format(&mut cursor, &img, tdim_x, tdim_y, ColorType::Rgb8, Png))?;
  87     Ok(cursor)
  88 }
  89
  90 #[get("/gen/0/{data}")]
  91 async fn img_gen0(req: HttpRequest) -> Result<impl Responder> {
  92     let data = req.uri().path().split("/").skip(3).next().unwrap();
  93     let cursor = make_png(32, 32, 16, percent_decode_str(&data).into_iter().borrow_mut())?;
  94     Ok(HttpResponse::build(StatusCode::OK)
  95        .content_type("image/png")
  96        .body(cursor.into_inner()))
  97 }
  98
  99 #[get("/gen/1/{dim_x}/{dim_y}/{scale}/{data}")]
 100 async fn img_gen1(req: HttpRequest, dim_x: web::Path<u16>, dim_y: web::Path<u16>, scale: web::Path<u8>) -> Result<impl Responder> {
 101     Ok(HttpResponse::build(StatusCode::OK))
 102 }
 103
 104 #[actix_web::main] // or #[tokio::main]
 105 async fn main() -> std::io::Result<()> {
 106     HttpServer::new(|| {
 107         App::new()
 108             .service(greet)
 109             .service(img_gen0)
 110             .service(img_gen1)
 111     })
 112     .bind(("127.0.0.1", 8080))?
 113     .run()
 114     .await
 115 }