src/main.rs

   1 use std::convert::From;
   2 use std::io::Cursor;
   3 use std::fmt::Display;
   4 use std::fmt;
   5 use std::borrow::BorrowMut;
   6 use std::sync::{Arc, Mutex};
   7 use num_traits::Zero;
   8 use num_traits::cast::AsPrimitive;
   9 use percent_encoding::percent_decode_str;
  10 use actix_web::{get, web, App, HttpServer, HttpRequest, HttpResponse, Responder, ResponseError, Result};
  11 use actix_web::body::BoxBody;
  12 use actix_web::http::StatusCode;
  13 use image::{ImageBuffer, ColorType, Rgb, RgbImage, write_buffer_with_format};
  14 use image::ImageOutputFormat::Png;
  15 use image::imageops::{FilterType, resize};
  16 use image::error::{LimitError, LimitErrorKind};
  17
  18
  19 #[derive(Debug)]
  20 struct ImageError(image::ImageError);
  21
  22 impl ImageError {
  23     fn dimension_error() -> ImageError {
  24         ImageError(image::ImageError::Limits(LimitError::from_kind(LimitErrorKind::DimensionError)))
  25     }
  26 }
  27
  28 impl Display for ImageError {
  29     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  30         write!(f, "{}", &self.0)
  31     }
  32 }
  33
  34 impl ResponseError for ImageError {
  35     fn status_code(&self) -> StatusCode {
  36         StatusCode::INTERNAL_SERVER_ERROR
  37     }
  38
  39     fn error_response(&self) -> HttpResponse<BoxBody> {
  40         HttpResponse::InternalServerError().body(format!("{}\n", &self))
  41     }
  42 }
  43
  44 #[derive(Debug)]
  45 enum CanvasError {
  46     NotExists,
  47     DimensionMismatch((u32, u32)),
  48     ImageError(ImageError)
  49 }
  50
  51 impl Display for CanvasError {
  52     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  53         write!(f, "Canvas Error: see error_response() for more details")
  54     }
  55 }
  56
  57 impl ResponseError for CanvasError {
  58     fn status_code(&self) -> StatusCode {
  59         match &self {
  60             CanvasError::NotExists => StatusCode::NOT_FOUND,
  61             CanvasError::DimensionMismatch(_) => StatusCode::BAD_REQUEST,
  62             CanvasError::ImageError(e) => e.status_code()
  63         }
  64     }
  65
  66     fn error_response(&self) -> HttpResponse<BoxBody> {
  67         match &self {
  68             CanvasError::NotExists => HttpResponse::NotFound().body("Canvas does not exist."),
  69             CanvasError::DimensionMismatch(dim) =>
  70                 HttpResponse::BadRequest().body(format!("Supplied dimensions don't match the dimensions of existing canvas {:?}.", dim)),
  71             CanvasError::ImageError(e) => e.error_response()
  72         }
  73     }
  74 }
  75
  76 impl From<ImageError> for CanvasError {
  77     fn from(e: ImageError) -> CanvasError {
  78         CanvasError::ImageError(e)
  79     }
  80 }
  81
  82 struct ToRgbIter<'a, T> where T: AsPrimitive<u8> {
  83     iter: Box<&'a mut dyn Iterator<Item = T>>
  84 }
  85
  86 impl<'a, T: AsPrimitive<u8>> ToRgbIter<'a, T> {
  87     fn new(data: &'a mut (dyn Iterator<Item = T>)) -> ToRgbIter<T> {
  88         ToRgbIter { iter: Box::new(data) }
  89     }
  90 }
  91
  92 impl<T: AsPrimitive<u8> + Zero> Iterator for ToRgbIter<'_, T> {
  93     type Item = Rgb<u8>;
  94     fn next(&mut self) -> Option<Rgb<u8>> {
  95         if let Some(r) = self.iter.next() {
  96             let g = self.iter.next().unwrap_or(T::zero());
  97             let b = self.iter.next().unwrap_or(T::zero());
  98             Some(Rgb([r.as_(), g.as_(), b.as_()]))
  99         }
 100         else {
 101             None
 102         }
 103     }
 104 }
 105
 106 fn to_imageresult<T> (result: Result<T, image::ImageError>) -> Result<T, ImageError> {
 107     match result {
 108         Ok(v) => Ok(v),
 109         Err(e) => Err(ImageError(e))
 110     }
 111 }
 112
 113 fn to_canvasresult<T: std::fmt::Debug> (result: Result<T, ImageError>) -> Result<T, CanvasError> {
 114     println!("Converting to canvasresult: {:?}", result);
 115     match result {
 116         Ok(v) => Ok(v),
 117         Err(e) => Err(CanvasError::ImageError(e))
 118     }
 119 }
 120
 121 #[derive(Debug)]
 122 struct Canvas {
 123     pen: usize,
 124     img: RgbImage
 125 }
 126
 127 impl Canvas {
 128     fn new(width: u32, height: u32) -> Canvas {
 129         Canvas { pen: 0, img: ImageBuffer::new(width, height) }
 130     }
 131
 132     fn from_image(img: RgbImage) -> Canvas {
 133         Canvas { pen: 0, img }
 134     }
 135
 136     /*fn replace(&self, img: RgbImage, pen: usize) -> Canvas {
 137         self.img = img;
 138         self.pen = pen;
 139         self
 140     }*/
 141
 142     fn advance_pen(mut self, offset: usize) -> Canvas {
 143         //Canvas { pen: self.pen + offset, img: self.img }
 144         self.pen += offset;
 145         self.pen %= self.img.width() as usize * self.img.height() as usize;
 146         self
 147     }
 148 }
 149
 150 struct Canvas0(Option<Canvas>);
 151 struct Canvas1(Option<Canvas>);
 152
 153 #[get("/hello/{name}")]
 154 async fn greet(name: web::Path<String>, req: HttpRequest) -> impl Responder {
 155     println!("{:?}", req);
 156     format!("Hello {name}!")
 157 }
 158
 159 fn rgb_encode_to_canvas(mut canvas: Canvas, data: &mut dyn Iterator<Item = u8>) -> Result<Canvas, ImageError> {
 160     let mut pixels = canvas.img.pixels_mut().skip(canvas.pen);
 161     let mut counter = 0;
 162
 163     for sp in ToRgbIter::new(data) {
 164         let mut dp = match pixels.next() {
 165             Some(pixel) => pixel,
 166             None => {
 167                 pixels = canvas.img.pixels_mut().skip(0);
 168                 pixels.next().ok_or(ImageError::dimension_error())?
 169             }
 170         };
 171         println!("{:?}", sp);
 172         dp.0 = sp.0;
 173         counter += 1;
 174     }
 175
 176     Ok(canvas.advance_pen(counter))
 177 }
 178
 179 fn rgb_encode(img: RgbImage, data: &mut dyn Iterator<Item = u8>) -> Result<RgbImage, ImageError> {
 180     Ok(rgb_encode_to_canvas(Canvas::from_image(img), data)?.img)
 181 }
 182
 183 fn apply_to_canvas<'a, F>(f: F, canvas_option: &'a mut Option<Canvas>, dimensions: Option<(u32, u32)>, data: &str) -> Result<&'a mut Canvas, CanvasError>
 184     where F: Fn(Canvas, &mut dyn Iterator<Item = u8>) -> Result<Canvas, CanvasError>
 185 {
 186     let canvas = match canvas_option.take() {
 187         Some(canvas) => match dimensions {
 188             Some(dimensions) => {
 189                 if dimensions == canvas.img.dimensions() {
 190                     Ok(canvas)
 191                 }
 192                 else {
 193                     Err(CanvasError::DimensionMismatch(canvas_option.insert(canvas).img.dimensions()))
 194                 }
 195             },
 196             None =>
 197                 Ok(canvas)
 198         },
 199         None => match dimensions {
 200             Some((dim_x, dim_y)) =>
 201                 Ok(Canvas::new(dim_x, dim_y)),
 202             None =>
 203                 Err(CanvasError::NotExists)
 204         }
 205     }?;
 206
 207     Ok(canvas_option.insert(f(canvas, percent_decode_str(&data).into_iter().borrow_mut())?))
 208 }
 209
 210 fn make_png(dim_x: u32, dim_y: u32, scale: u32, data: &mut dyn Iterator<Item = u8>) -> Result<Cursor<Vec<u8>>, ImageError> {
 211     // Image must not be larger than 1 megapixel
 212     if dim_x * dim_y * scale > 1048576 {
 213         return Err(ImageError::dimension_error())
 214     }
 215
 216     let img: RgbImage = rgb_encode(ImageBuffer::new(dim_x, dim_y), data)?;
 217
 218     let tdim_x = dim_x * scale;
 219     let tdim_y = dim_y * scale;
 220     let img = resize(&img, tdim_x, tdim_y, FilterType::Nearest);
 221     let mut cursor = Cursor::new(Vec::new());
 222     to_imageresult(write_buffer_with_format(&mut cursor, &img, tdim_x, tdim_y, ColorType::Rgb8, Png))?;
 223     Ok(cursor)
 224 }
 225
 226 fn image_to_cursor(img: RgbImage, scale: u32) -> Result<Cursor<Vec<u8>>, ImageError> {
 227     let (dim_x, dim_y) = img.dimensions();
 228     let (dim_x, dim_y) = (dim_x * scale, dim_y * scale);
 229
 230     // Image must not be larger than 1 megapixel
 231     if dim_x * dim_y > 1048576 {
 232         return Err(ImageError::dimension_error())
 233     }
 234
 235     let mut cursor = Cursor::new(Vec::new());
 236     let img = resize(&img, dim_x, dim_y, FilterType::Nearest);
 237     to_imageresult(write_buffer_with_format(&mut cursor, &img, dim_x, dim_y, ColorType::Rgb8, Png))?;
 238     Ok(cursor)
 239 }
 240
 241
 242 #[get("/gen/0/{data}")]
 243 async fn img_gen0(req: HttpRequest) -> Result<impl Responder> {
 244     let data = req.uri().path().split("/").skip(3).next().unwrap();
 245     let cursor = make_png(32, 32, 16, percent_decode_str(&data).into_iter().borrow_mut())?;
 246     Ok(HttpResponse::build(StatusCode::OK)
 247        .content_type("image/png")
 248        .body(cursor.into_inner()))
 249 }
 250
 251 #[get("/gen/1/{dim_x}/{dim_y}/{scale}/{data}")]
 252 async fn img_gen1(req: HttpRequest, path: web::Path<(u32, u32, u32)>) -> Result<impl Responder> {
 253     let (dim_x, dim_y, scale) = path.into_inner();
 254     let data = req.uri().path().split("/").skip(6).next().unwrap();
 255     let cursor = make_png(dim_x, dim_y, scale, percent_decode_str(&data).into_iter().borrow_mut())?;
 256     Ok(HttpResponse::build(StatusCode::OK)
 257        .content_type("image/png")
 258        .body(cursor.into_inner()))
 259 }
 260
 261 #[get("/pgen/0/{data}")]
 262 async fn img_pgen0(req: HttpRequest, canvas0: web::Data<Arc<Mutex<Canvas0>>>) -> Result<impl Responder> {
 263     let data = req.uri().path().split("/").skip(3).next().unwrap();
 264     let scale = 16;
 265     let img: RgbImage = ({
 266         let canvas_option = &mut *canvas0.lock().unwrap();
 267         Ok(apply_to_canvas( |c, d| to_canvasresult(rgb_encode_to_canvas(c, d)), &mut canvas_option.0, None, data)?.img.clone())
 268     } as Result<RgbImage, CanvasError>)?;
 269     let cursor = image_to_cursor(img, scale)?;
 270     Ok(HttpResponse::build(StatusCode::OK)
 271        .content_type("image/png")
 272        .body(cursor.into_inner()))
 273 }
 274
 275 #[get("/pgen/1/{dim_x}/{dim_y}/{scale}/{data}")]
 276 async fn img_pgen1(req: HttpRequest, path: web::Path<(u32, u32, u32)>, canvas1: web::Data<Arc<Mutex<Canvas1>>>) -> Result<impl Responder> {
 277     let (dim_x, dim_y, scale) = path.into_inner();
 278     let data = req.uri().path().split("/").skip(6).next().unwrap();
 279     let img: RgbImage = ({
 280         let canvas_option = &mut *canvas1.lock().unwrap();
 281         Ok(apply_to_canvas( |c, d| to_canvasresult(rgb_encode_to_canvas(c, d)), &mut canvas_option.0, Some((dim_x, dim_y)), data)?.img.clone())
 282     } as Result<RgbImage, CanvasError>)?;
 283     let cursor = image_to_cursor(img, scale)?;
 284     Ok(HttpResponse::build(StatusCode::OK)
 285        .content_type("image/png")
 286        .body(cursor.into_inner()))
 287 }
 288
 289
 290 #[actix_web::main] // or #[tokio::main]
 291 async fn main() -> std::io::Result<()> {
 292     env_logger::init();
 293     let canvas0 = Arc::new(Mutex::new(Canvas0(Some(Canvas::new(32, 32)))));
 294     let canvas1 = Arc::new(Mutex::new(Canvas1(None)));
 295     HttpServer::new(move || {
 296         App::new()
 297             .service(greet)
 298             .service(img_gen0)
 299             .service(img_gen1)
 300             .service(img_pgen0)
 301             .service(img_pgen1)
 302             .app_data(web::Data::new(canvas0.clone()))
 303             .app_data(web::Data::new(canvas1.clone()))
 304     })
 305     .bind(("127.0.0.1", 8080))?
 306     .run()
 307     .await
 308 }