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.pen %= self.img.width() as usize * self.img.height() as usize;
 123         self
 124     }
 125 }
 126
 127 #[get("/hello/{name}")]
 128 async fn greet(name: web::Path<String>, req: HttpRequest) -> impl Responder {
 129     println!("{:?}", req);
 130     format!("Hello {name}!")
 131 }
 132
 133 fn rgb_encode_to_canvas(mut canvas: Canvas, data: &mut dyn Iterator<Item = u8>) -> Result<Canvas, ImageError> {
 134     let mut pixels = canvas.img.pixels_mut().skip(canvas.pen);
 135     let mut counter = 0;
 136
 137     for sp in ToRgbIter::new(data) {
 138         let mut dp = match pixels.next() {
 139             Some(pixel) => pixel,
 140             None => {
 141                 pixels = canvas.img.pixels_mut().skip(0);
 142                 pixels.next().ok_or(ImageError::dimension_error())?
 143             }
 144         };
 145         println!("{:?}", sp);
 146         dp.0 = sp.0;
 147         counter += 1;
 148     }
 149
 150     Ok(canvas.advance_pen(counter))
 151 }
 152
 153 fn rgb_encode(img: RgbImage, data: &mut dyn Iterator<Item = u8>) -> Result<RgbImage, ImageError> {
 154     Ok(rgb_encode_to_canvas(Canvas::from_image(img), data)?.img)
 155 }
 156
 157 fn make_png(dim_x: u32, dim_y: u32, scale: u32, data: &mut dyn Iterator<Item = u8>) -> Result<Cursor<Vec<u8>>, ImageError> {
 158     // Image must not be larger than 1 megapixel
 159     if dim_x * dim_y * scale > 1048576 {
 160         return Err(ImageError::dimension_error())
 161     }
 162
 163     let img: RgbImage = rgb_encode(ImageBuffer::new(dim_x, dim_y), data)?;
 164
 165     let tdim_x = dim_x * scale;
 166     let tdim_y = dim_y * scale;
 167     let img = resize(&img, tdim_x, tdim_y, FilterType::Nearest);
 168     let mut cursor = Cursor::new(Vec::new());
 169     to_imageresult(write_buffer_with_format(&mut cursor, &img, tdim_x, tdim_y, ColorType::Rgb8, Png))?;
 170     Ok(cursor)
 171 }
 172
 173 #[get("/gen/0/{data}")]
 174 async fn img_gen0(req: HttpRequest) -> Result<impl Responder> {
 175     let data = req.uri().path().split("/").skip(3).next().unwrap();
 176     let cursor = make_png(32, 32, 16, percent_decode_str(&data).into_iter().borrow_mut())?;
 177     Ok(HttpResponse::build(StatusCode::OK)
 178        .content_type("image/png")
 179        .body(cursor.into_inner()))
 180 }
 181
 182 #[get("/gen/1/{dim_x}/{dim_y}/{scale}/{data}")]
 183 async fn img_gen1(req: HttpRequest, path: web::Path<(u32, u32, u32)>) -> Result<impl Responder> {
 184     let (dim_x, dim_y, scale) = path.into_inner();
 185     let data = req.uri().path().split("/").skip(6).next().unwrap();
 186     let cursor = make_png(dim_x, dim_y, scale, percent_decode_str(&data).into_iter().borrow_mut())?;
 187     Ok(HttpResponse::build(StatusCode::OK)
 188        .content_type("image/png")
 189        .body(cursor.into_inner()))
 190 }
 191
 192 #[get("/pgen/0/{data}")]
 193 async fn img_pgen0(req: HttpRequest, canvas0: web::Data<Arc<Mutex<Option<Canvas>>>>) -> Result<impl Responder> {
 194     let data = req.uri().path().split("/").skip(3).next().unwrap();
 195     let mut cursor = Cursor::new(Vec::new());
 196     let scale = 16;
 197     let img: RgbImage = {
 198         let canvas_option = &mut *canvas0.lock().unwrap();
 199         let canvas = canvas_option.take().ok_or(CanvasError::NotExists)?;
 200         let canvas = rgb_encode_to_canvas(canvas, percent_decode_str(&data).into_iter().borrow_mut())?;
 201         canvas_option.insert(canvas).img.clone()
 202     };
 203     let (tdim_x, tdim_y) = img.dimensions();
 204     let (tdim_x, tdim_y) = (tdim_x * scale, tdim_y * scale);
 205     let img = resize(&img, tdim_x, tdim_y, FilterType::Nearest);
 206     to_imageresult(write_buffer_with_format(&mut cursor, &img, tdim_x, tdim_y, ColorType::Rgb8, Png))?;
 207     Ok(HttpResponse::build(StatusCode::OK)
 208        .content_type("image/png")
 209        .body(cursor.into_inner()))
 210 }
 211
 212 #[actix_web::main] // or #[tokio::main]
 213 async fn main() -> std::io::Result<()> {
 214     env_logger::init();
 215     let canvas0 = Arc::new(Mutex::new(Some(Canvas::new(32, 32))));
 216     HttpServer::new(move || {
 217         App::new()
 218             .service(greet)
 219             .service(img_gen0)
 220             .service(img_gen1)
 221             .service(img_pgen0)
 222             .app_data(web::Data::new(canvas0.clone()))
 223     })
 224     .bind(("127.0.0.1", 8080))?
 225     .run()
 226     .await
 227 }