src/main.rs

   1 use std::io::Cursor;
   2 use std::fmt::Display;
   3 use std::fmt;
   4 use std::borrow::BorrowMut;
   5 use std::sync::{Arc, Mutex};
   6 use num_traits::Zero;
   7 use num_traits::cast::AsPrimitive;
   8 use percent_encoding::percent_decode_str;
   9 use actix_web::{get, web, App, HttpServer, HttpRequest, HttpResponse, Responder, ResponseError, Result};
  10 use actix_web::body::BoxBody;
  11 use actix_web::http::StatusCode;
  12 use image::{ImageBuffer, ColorType, Rgb, RgbImage, write_buffer_with_format};
  13 use image::ImageOutputFormat::Png;
  14 use image::imageops::{FilterType, resize};
  15 use image::error::{LimitError, LimitErrorKind};
  16
  17
  18 #[derive(Debug)]
  19 struct ImageError(image::ImageError);
  20
  21 impl ImageError {
  22     fn dimension_error() -> ImageError {
  23         ImageError(image::ImageError::Limits(LimitError::from_kind(LimitErrorKind::DimensionError)))
  24     }
  25 }
  26
  27 impl Display for ImageError {
  28     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  29         write!(f, "{}", &self.0)
  30     }
  31 }
  32
  33 impl ResponseError for ImageError {
  34     fn status_code(&self) -> StatusCode {
  35         StatusCode::INTERNAL_SERVER_ERROR
  36     }
  37
  38     fn error_response(&self) -> HttpResponse<BoxBody> {
  39         HttpResponse::InternalServerError().body(format!("{}\n", &self))
  40     }
  41 }
  42
  43 struct ToRgbIter<'a, T> where T: AsPrimitive<u8> {
  44     iter: Box<&'a mut dyn Iterator<Item = T>>
  45 }
  46
  47 impl<'a, T: AsPrimitive<u8>> ToRgbIter<'a, T> {
  48     fn new(data: &'a mut (dyn Iterator<Item = T>)) -> ToRgbIter<T> {
  49         ToRgbIter { iter: Box::new(data) }
  50     }
  51 }
  52
  53 impl<T: AsPrimitive<u8> + Zero> Iterator for ToRgbIter<'_, T> {
  54     type Item = Rgb<u8>;
  55     fn next(&mut self) -> Option<Rgb<u8>> {
  56         if let Some(r) = self.iter.next() {
  57             let g = self.iter.next().unwrap_or(T::zero());
  58             let b = self.iter.next().unwrap_or(T::zero());
  59             Some(Rgb([r.as_(), g.as_(), b.as_()]))
  60         }
  61         else {
  62             None
  63         }
  64     }
  65 }
  66
  67 fn to_imageresult<T> (result: Result<T, image::ImageError>) -> Result<T, ImageError> {
  68     match result {
  69         Ok(v) => Ok(v),
  70         Err(e) => Err(ImageError(e))
  71     }
  72 }
  73
  74 struct Canvas {
  75     pen: usize,
  76     img: RgbImage
  77 }
  78
  79 impl Canvas {
  80     fn new(width: u32, height: u32) -> Canvas {
  81         Canvas { pen: 0, img: ImageBuffer::new(width, height) }
  82     }
  83
  84     fn from_image(img: RgbImage) -> Canvas {
  85         Canvas { pen: 0, img }
  86     }
  87
  88     /*fn replace(&self, img: RgbImage, pen: usize) -> Canvas {
  89         self.img = img;
  90         self.pen = pen;
  91         self
  92     }*/
  93
  94     fn advance_pen(mut self, offset: usize) -> Canvas {
  95         //Canvas { pen: self.pen + offset, img: self.img }
  96         self.pen += offset;
  97         self
  98     }
  99 }
 100
 101 #[get("/hello/{name}")]
 102 async fn greet(name: web::Path<String>, req: HttpRequest) -> impl Responder {
 103     println!("{:?}", req);
 104     format!("Hello {name}!")
 105 }
 106
 107 fn rgb_encode_to_canvas(mut canvas: Canvas, data: &mut dyn Iterator<Item = u8>) -> Result<Canvas, ImageError> {
 108     let mut pixels = canvas.img.pixels_mut().skip(canvas.pen);
 109     let mut counter = 0;
 110
 111     for sp in ToRgbIter::new(data) {
 112         let mut dp = pixels.next().ok_or(ImageError::dimension_error())?;
 113         println!("{:?}", sp);
 114         dp.0 = sp.0;
 115         counter += 1;
 116     }
 117
 118     Ok(canvas.advance_pen(counter))
 119 }
 120
 121 fn rgb_encode(img: RgbImage, data: &mut dyn Iterator<Item = u8>) -> Result<RgbImage, ImageError> {
 122     Ok(rgb_encode_to_canvas(Canvas::from_image(img), data)?.img)
 123 }
 124
 125 fn make_png(dim_x: u32, dim_y: u32, scale: u32, data: &mut dyn Iterator<Item = u8>) -> Result<Cursor<Vec<u8>>, ImageError> {
 126     // Image must not be larger than 1 megapixel
 127     if dim_x * dim_y * scale > 1048576 {
 128         return Err(ImageError::dimension_error())
 129     }
 130
 131     let mut img: RgbImage = rgb_encode(ImageBuffer::new(dim_x, dim_y), data)?;
 132
 133     let tdim_x = dim_x * scale;
 134     let tdim_y = dim_y * scale;
 135     let img = resize(&img, tdim_x, tdim_y, FilterType::Nearest);
 136     let mut cursor = Cursor::new(Vec::new());
 137     to_imageresult(write_buffer_with_format(&mut cursor, &img, tdim_x, tdim_y, ColorType::Rgb8, Png))?;
 138     Ok(cursor)
 139 }
 140
 141 #[get("/gen/0/{data}")]
 142 async fn img_gen0(req: HttpRequest) -> Result<impl Responder> {
 143     let data = req.uri().path().split("/").skip(3).next().unwrap();
 144     let cursor = make_png(32, 32, 16, percent_decode_str(&data).into_iter().borrow_mut())?;
 145     Ok(HttpResponse::build(StatusCode::OK)
 146        .content_type("image/png")
 147        .body(cursor.into_inner()))
 148 }
 149
 150 #[get("/gen/1/{dim_x}/{dim_y}/{scale}/{data}")]
 151 async fn img_gen1(req: HttpRequest, path: web::Path<(u32, u32, u32)>) -> Result<impl Responder> {
 152     let (dim_x, dim_y, scale) = path.into_inner();
 153     let data = req.uri().path().split("/").skip(6).next().unwrap();
 154     let cursor = make_png(dim_x, dim_y, scale, percent_decode_str(&data).into_iter().borrow_mut())?;
 155     Ok(HttpResponse::build(StatusCode::OK)
 156        .content_type("image/png")
 157        .body(cursor.into_inner()))
 158 }
 159
 160 #[get("/pgen/0/{data}")]
 161 async fn img_pgen0(req: HttpRequest, canvas0: web::Data<Arc<Mutex<Option<Canvas>>>>) -> Result<impl Responder> {
 162     let data = req.uri().path().split("/").skip(3).next().unwrap();
 163     let mut cursor = Cursor::new(Vec::new());
 164     let scale = 16;
 165     let tdim_x = 32 * scale;
 166     let tdim_y = 32 * scale;
 167     let img: RgbImage = {
 168         let mut canvas_option = &mut *canvas0.lock().unwrap();
 169         let canvas = canvas_option.take();
 170         let canvas = rgb_encode_to_canvas(canvas.expect("Canvas doesn't exist!"), percent_decode_str(&data).into_iter().borrow_mut())?;
 171         canvas_option.insert(canvas).img.clone()
 172     };
 173     let img = resize(&img, tdim_x, tdim_y, FilterType::Nearest);
 174     to_imageresult(write_buffer_with_format(&mut cursor, &img, tdim_x, tdim_y, ColorType::Rgb8, Png))?;
 175     Ok(HttpResponse::build(StatusCode::OK)
 176        .content_type("image/png")
 177        .body(cursor.into_inner()))
 178 }
 179
 180 #[actix_web::main] // or #[tokio::main]
 181 async fn main() -> std::io::Result<()> {
 182     env_logger::init();
 183     let canvas0 = Arc::new(Mutex::new(Some(Canvas::new(32, 32))));
 184     HttpServer::new(move || {
 185         App::new()
 186             .service(greet)
 187             .service(img_gen0)
 188             .service(img_gen1)
 189             .service(img_pgen0)
 190             .app_data(web::Data::new(canvas0.clone()))
 191     })
 192     .bind(("127.0.0.1", 8080))?
 193     .run()
 194     .await
 195 }