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,
  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 => HttpResponse::BadRequest().body("Supplied dimensions don't much the dimensions of existing canvas."),
  70             CanvasError::ImageError(e) => e.error_response()
  71         }
  72     }
  73 }
  74
  75 impl From<ImageError> for CanvasError {
  76     fn from(e: ImageError) -> CanvasError {
  77         CanvasError::ImageError(e)
  78     }
  79 }
  80
  81 struct ToRgbIter<'a, T> where T: AsPrimitive<u8> {
  82     iter: Box<&'a mut dyn Iterator<Item = T>>
  83 }
  84
  85 impl<'a, T: AsPrimitive<u8>> ToRgbIter<'a, T> {
  86     fn new(data: &'a mut (dyn Iterator<Item = T>)) -> ToRgbIter<T> {
  87         ToRgbIter { iter: Box::new(data) }
  88     }
  89 }
  90
  91 impl<T: AsPrimitive<u8> + Zero> Iterator for ToRgbIter<'_, T> {
  92     type Item = Rgb<u8>;
  93     fn next(&mut self) -> Option<Rgb<u8>> {
  94         if let Some(r) = self.iter.next() {
  95             let g = self.iter.next().unwrap_or(T::zero());
  96             let b = self.iter.next().unwrap_or(T::zero());
  97             Some(Rgb([r.as_(), g.as_(), b.as_()]))
  98         }
  99         else {
 100             None
 101         }
 102     }
 103 }
 104
 105 fn to_imageresult<T> (result: Result<T, image::ImageError>) -> Result<T, ImageError> {
 106     match result {
 107         Ok(v) => Ok(v),
 108         Err(e) => Err(ImageError(e))
 109     }
 110 }
 111
 112 fn to_canvasresult<T: std::fmt::Debug> (result: Result<T, ImageError>) -> Result<T, CanvasError> {
 113     println!("Converting to canvasresult: {:?}", result);
 114     match result {
 115         Ok(v) => Ok(v),
 116         Err(e) => Err(CanvasError::ImageError(e))
 117     }
 118 }
 119
 120 #[derive(Debug)]
 121 struct Canvas {
 122     pen: usize,
 123     img: RgbImage
 124 }
 125
 126 impl Canvas {
 127     fn new(width: u32, height: u32) -> Canvas {
 128         Canvas { pen: 0, img: ImageBuffer::new(width, height) }
 129     }
 130
 131     fn from_image(img: RgbImage) -> Canvas {
 132         Canvas { pen: 0, img }
 133     }
 134
 135     /*fn replace(&self, img: RgbImage, pen: usize) -> Canvas {
 136         self.img = img;
 137         self.pen = pen;
 138         self
 139     }*/
 140
 141     fn advance_pen(mut self, offset: usize) -> Canvas {
 142         //Canvas { pen: self.pen + offset, img: self.img }
 143         self.pen += offset;
 144         self.pen %= self.img.width() as usize * self.img.height() as usize;
 145         self
 146     }
 147 }
 148
 149 #[get("/hello/{name}")]
 150 async fn greet(name: web::Path<String>, req: HttpRequest) -> impl Responder {
 151     println!("{:?}", req);
 152     format!("Hello {name}!")
 153 }
 154
 155 fn rgb_encode_to_canvas(mut canvas: Canvas, data: &mut dyn Iterator<Item = u8>) -> Result<Canvas, ImageError> {
 156     let mut pixels = canvas.img.pixels_mut().skip(canvas.pen);
 157     let mut counter = 0;
 158
 159     for sp in ToRgbIter::new(data) {
 160         let mut dp = match pixels.next() {
 161             Some(pixel) => pixel,
 162             None => {
 163                 pixels = canvas.img.pixels_mut().skip(0);
 164                 pixels.next().ok_or(ImageError::dimension_error())?
 165             }
 166         };
 167         println!("{:?}", sp);
 168         dp.0 = sp.0;
 169         counter += 1;
 170     }
 171
 172     Ok(canvas.advance_pen(counter))
 173 }
 174
 175 fn rgb_encode(img: RgbImage, data: &mut dyn Iterator<Item = u8>) -> Result<RgbImage, ImageError> {
 176     Ok(rgb_encode_to_canvas(Canvas::from_image(img), data)?.img)
 177 }
 178
 179 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>
 180     where F: Fn(Canvas, &mut dyn Iterator<Item = u8>) -> Result<Canvas, CanvasError>
 181 {
 182     let canvas = match canvas_option.take() {
 183         Some(canvas) => match dimensions {
 184             Some(dimensions) => {
 185                 if dimensions == canvas.img.dimensions() {
 186                     Ok(canvas)
 187                 }
 188                 else {
 189                     _ = canvas_option.insert(canvas);
 190                     Err(CanvasError::DimensionMismatch)
 191                 }
 192             },
 193             None =>
 194                 Ok(canvas)
 195         },
 196         None => match dimensions {
 197             Some((dim_x, dim_y)) =>
 198                 Ok(Canvas::new(dim_x, dim_y)),
 199             None =>
 200                 Err(CanvasError::NotExists)
 201         }
 202     }?;
 203
 204     Ok(canvas_option.insert(f(canvas, percent_decode_str(&data).into_iter().borrow_mut())?))
 205 }
 206
 207 fn make_png(dim_x: u32, dim_y: u32, scale: u32, data: &mut dyn Iterator<Item = u8>) -> Result<Cursor<Vec<u8>>, ImageError> {
 208     // Image must not be larger than 1 megapixel
 209     if dim_x * dim_y * scale > 1048576 {
 210         return Err(ImageError::dimension_error())
 211     }
 212
 213     let img: RgbImage = rgb_encode(ImageBuffer::new(dim_x, dim_y), data)?;
 214
 215     let tdim_x = dim_x * scale;
 216     let tdim_y = dim_y * scale;
 217     let img = resize(&img, tdim_x, tdim_y, FilterType::Nearest);
 218     let mut cursor = Cursor::new(Vec::new());
 219     to_imageresult(write_buffer_with_format(&mut cursor, &img, tdim_x, tdim_y, ColorType::Rgb8, Png))?;
 220     Ok(cursor)
 221 }
 222
 223 #[get("/gen/0/{data}")]
 224 async fn img_gen0(req: HttpRequest) -> Result<impl Responder> {
 225     let data = req.uri().path().split("/").skip(3).next().unwrap();
 226     let cursor = make_png(32, 32, 16, percent_decode_str(&data).into_iter().borrow_mut())?;
 227     Ok(HttpResponse::build(StatusCode::OK)
 228        .content_type("image/png")
 229        .body(cursor.into_inner()))
 230 }
 231
 232 #[get("/gen/1/{dim_x}/{dim_y}/{scale}/{data}")]
 233 async fn img_gen1(req: HttpRequest, path: web::Path<(u32, u32, u32)>) -> Result<impl Responder> {
 234     let (dim_x, dim_y, scale) = path.into_inner();
 235     let data = req.uri().path().split("/").skip(6).next().unwrap();
 236     let cursor = make_png(dim_x, dim_y, scale, percent_decode_str(&data).into_iter().borrow_mut())?;
 237     Ok(HttpResponse::build(StatusCode::OK)
 238        .content_type("image/png")
 239        .body(cursor.into_inner()))
 240 }
 241
 242 #[get("/pgen/0/{data}")]
 243 async fn img_pgen0(req: HttpRequest, canvas0: web::Data<Arc<Mutex<Option<Canvas>>>>) -> Result<impl Responder> {
 244     let data = req.uri().path().split("/").skip(3).next().unwrap();
 245     let mut cursor = Cursor::new(Vec::new());
 246     let scale = 16;
 247     let img: RgbImage = ({
 248         let canvas_option = &mut *canvas0.lock().unwrap();
 249         Ok(apply_to_canvas( |c, d| to_canvasresult(rgb_encode_to_canvas(c, d)), canvas_option, None, data)?.img.clone())
 250     } as Result<RgbImage, CanvasError>)?;
 251     let (tdim_x, tdim_y) = img.dimensions();
 252     let (tdim_x, tdim_y) = (tdim_x * scale, tdim_y * scale);
 253     let img = resize(&img, tdim_x, tdim_y, FilterType::Nearest);
 254     to_imageresult(write_buffer_with_format(&mut cursor, &img, tdim_x, tdim_y, ColorType::Rgb8, Png))?;
 255     Ok(HttpResponse::build(StatusCode::OK)
 256        .content_type("image/png")
 257        .body(cursor.into_inner()))
 258 }
 259
 260 #[get("/pgen/1/{dim_x}/{dim_y}/{scale}/{data}")]
 261 async fn img_pgen1(req: HttpRequest, path: web::Path<(u32, u32, u32)>, canvas1: web::Data<Arc<Mutex<Option<Canvas>>>>) -> Result<impl Responder> {
 262     let (dim_x, dim_y, scale) = path.into_inner();
 263     let data = req.uri().path().split("/").skip(6).next().unwrap();
 264     let img: RgbImage = ({
 265         let canvas_option = &mut *canvas1.lock().unwrap();
 266         Ok(apply_to_canvas( |c, d| to_canvasresult(rgb_encode_to_canvas(c, d)), canvas_option, Some((dim_x, dim_y)), data)?.img.clone())
 267     } as Result<RgbImage, CanvasError>)?;
 268     let (tdim_x, tdim_y) = img.dimensions();
 269     let (tdim_x, tdim_y) = (tdim_x * scale, tdim_y * scale);
 270     let img = resize(&img, tdim_x, tdim_y, FilterType::Nearest);
 271     let mut cursor = Cursor::new(Vec::new());
 272     to_imageresult(write_buffer_with_format(&mut cursor, &img, tdim_x, tdim_y, ColorType::Rgb8, Png))?;
 273     Ok(HttpResponse::build(StatusCode::OK)
 274        .content_type("image/png")
 275        .body(cursor.into_inner()))
 276 }
 277
 278
 279 #[actix_web::main] // or #[tokio::main]
 280 async fn main() -> std::io::Result<()> {
 281     env_logger::init();
 282     let canvas0 = Arc::new(Mutex::new(Some(Canvas::new(32, 32))));
 283     let canvas1 = Arc::new(Mutex::new(None as Option<Canvas>));
 284     HttpServer::new(move || {
 285         App::new()
 286             .service(greet)
 287             .service(img_gen0)
 288             .service(img_gen1)
 289             .service(img_pgen0)
 290             .service(img_pgen1)
 291             .app_data(web::Data::new(canvas0.clone()))
 292             .app_data(web::Data::new(canvas1.clone()))
 293     })
 294     .bind(("127.0.0.1", 8080))?
 295     .run()
 296     .await
 297 }