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 #[derive(Debug)]
  44 enum CanvasError {
  45     NotExists
  46 }
  47
  48 impl Display for CanvasError {
  49     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  50         write!(f, "Canvas Error: see error_response() for more details")
  51     }
  52 }
  53
  54 impl ResponseError for CanvasError {
  55     fn status_code(&self) -> StatusCode {
  56         match &self {
  57             CanvasError::NotExists => StatusCode::NOT_FOUND
  58         }
  59     }
  60
  61     fn error_response(&self) -> HttpResponse<BoxBody> {
  62         match &self {
  63             CanvasError::NotExists => HttpResponse::NotFound().body("Canvas does not exist.")
  64         }
  65     }
  66 }
  67
  68 struct ToRgbIter<'a, T> where T: AsPrimitive<u8> {
  69     iter: Box<&'a mut dyn Iterator<Item = T>>
  70 }
  71
  72 impl<'a, T: AsPrimitive<u8>> ToRgbIter<'a, T> {
  73     fn new(data: &'a mut (dyn Iterator<Item = T>)) -> ToRgbIter<T> {
  74         ToRgbIter { iter: Box::new(data) }
  75     }
  76 }
  77
  78 impl<T: AsPrimitive<u8> + Zero> Iterator for ToRgbIter<'_, T> {
  79     type Item = Rgb<u8>;
  80     fn next(&mut self) -> Option<Rgb<u8>> {
  81         if let Some(r) = self.iter.next() {
  82             let g = self.iter.next().unwrap_or(T::zero());
  83             let b = self.iter.next().unwrap_or(T::zero());
  84             Some(Rgb([r.as_(), g.as_(), b.as_()]))
  85         }
  86         else {
  87             None
  88         }
  89     }
  90 }
  91
  92 fn to_imageresult<T> (result: Result<T, image::ImageError>) -> Result<T, ImageError> {
  93     match result {
  94         Ok(v) => Ok(v),
  95         Err(e) => Err(ImageError(e))
  96     }
  97 }
  98
  99 struct Canvas {
 100     pen: usize,
 101     img: RgbImage
 102 }
 103
 104 impl Canvas {
 105     fn new(width: u32, height: u32) -> Canvas {
 106         Canvas { pen: 0, img: ImageBuffer::new(width, height) }
 107     }
 108
 109     fn from_image(img: RgbImage) -> Canvas {
 110         Canvas { pen: 0, img }
 111     }
 112
 113     /*fn replace(&self, img: RgbImage, pen: usize) -> Canvas {
 114         self.img = img;
 115         self.pen = pen;
 116         self
 117     }*/
 118
 119     fn advance_pen(mut self, offset: usize) -> Canvas {
 120         //Canvas { pen: self.pen + offset, img: self.img }
 121         self.pen += offset;
 122         self
 123     }
 124 }
 125
 126 #[get("/hello/{name}")]
 127 async fn greet(name: web::Path<String>, req: HttpRequest) -> impl Responder {
 128     println!("{:?}", req);
 129     format!("Hello {name}!")
 130 }
 131
 132 fn rgb_encode_to_canvas(mut canvas: Canvas, data: &mut dyn Iterator<Item = u8>) -> Result<Canvas, ImageError> {
 133     let mut pixels = canvas.img.pixels_mut().skip(canvas.pen);
 134     let mut counter = 0;
 135
 136     for sp in ToRgbIter::new(data) {
 137         let mut dp = pixels.next().ok_or(ImageError::dimension_error())?;
 138         println!("{:?}", sp);
 139         dp.0 = sp.0;
 140         counter += 1;
 141     }
 142
 143     Ok(canvas.advance_pen(counter))
 144 }
 145
 146 fn rgb_encode(img: RgbImage, data: &mut dyn Iterator<Item = u8>) -> Result<RgbImage, ImageError> {
 147     Ok(rgb_encode_to_canvas(Canvas::from_image(img), data)?.img)
 148 }
 149
 150 fn make_png(dim_x: u32, dim_y: u32, scale: u32, data: &mut dyn Iterator<Item = u8>) -> Result<Cursor<Vec<u8>>, ImageError> {
 151     // Image must not be larger than 1 megapixel
 152     if dim_x * dim_y * scale > 1048576 {
 153         return Err(ImageError::dimension_error())
 154     }
 155
 156     let img: RgbImage = rgb_encode(ImageBuffer::new(dim_x, dim_y), data)?;
 157
 158     let tdim_x = dim_x * scale;
 159     let tdim_y = dim_y * scale;
 160     let img = resize(&img, tdim_x, tdim_y, FilterType::Nearest);
 161     let mut cursor = Cursor::new(Vec::new());
 162     to_imageresult(write_buffer_with_format(&mut cursor, &img, tdim_x, tdim_y, ColorType::Rgb8, Png))?;
 163     Ok(cursor)
 164 }
 165
 166 #[get("/gen/0/{data}")]
 167 async fn img_gen0(req: HttpRequest) -> Result<impl Responder> {
 168     let data = req.uri().path().split("/").skip(3).next().unwrap();
 169     let cursor = make_png(32, 32, 16, percent_decode_str(&data).into_iter().borrow_mut())?;
 170     Ok(HttpResponse::build(StatusCode::OK)
 171        .content_type("image/png")
 172        .body(cursor.into_inner()))
 173 }
 174
 175 #[get("/gen/1/{dim_x}/{dim_y}/{scale}/{data}")]
 176 async fn img_gen1(req: HttpRequest, path: web::Path<(u32, u32, u32)>) -> Result<impl Responder> {
 177     let (dim_x, dim_y, scale) = path.into_inner();
 178     let data = req.uri().path().split("/").skip(6).next().unwrap();
 179     let cursor = make_png(dim_x, dim_y, scale, percent_decode_str(&data).into_iter().borrow_mut())?;
 180     Ok(HttpResponse::build(StatusCode::OK)
 181        .content_type("image/png")
 182        .body(cursor.into_inner()))
 183 }
 184
 185 #[get("/pgen/0/{data}")]
 186 async fn img_pgen0(req: HttpRequest, canvas0: web::Data<Arc<Mutex<Option<Canvas>>>>) -> Result<impl Responder> {
 187     let data = req.uri().path().split("/").skip(3).next().unwrap();
 188     let mut cursor = Cursor::new(Vec::new());
 189     let scale = 16;
 190     let img: RgbImage = {
 191         let canvas_option = &mut *canvas0.lock().unwrap();
 192         let canvas = canvas_option.take().ok_or(CanvasError::NotExists)?;
 193         let canvas = rgb_encode_to_canvas(canvas, percent_decode_str(&data).into_iter().borrow_mut())?;
 194         canvas_option.insert(canvas).img.clone()
 195     };
 196     let (tdim_x, tdim_y) = img.dimensions();
 197     let (tdim_x, tdim_y) = (tdim_x * scale, tdim_y * scale);
 198     let img = resize(&img, tdim_x, tdim_y, FilterType::Nearest);
 199     to_imageresult(write_buffer_with_format(&mut cursor, &img, tdim_x, tdim_y, ColorType::Rgb8, Png))?;
 200     Ok(HttpResponse::build(StatusCode::OK)
 201        .content_type("image/png")
 202        .body(cursor.into_inner()))
 203 }
 204
 205 #[actix_web::main] // or #[tokio::main]
 206 async fn main() -> std::io::Result<()> {
 207     env_logger::init();
 208     let canvas0 = Arc::new(Mutex::new(Some(Canvas::new(32, 32))));
 209     HttpServer::new(move || {
 210         App::new()
 211             .service(greet)
 212             .service(img_gen0)
 213             .service(img_gen1)
 214             .service(img_pgen0)
 215             .app_data(web::Data::new(canvas0.clone()))
 216     })
 217     .bind(("127.0.0.1", 8080))?
 218     .run()
 219     .await
 220 }