pict-rs/src/processor.rs
2020-06-07 14:12:19 -05:00

182 lines
3.9 KiB
Rust

use crate::error::UploadError;
use actix_web::web;
use image::{DynamicImage, GenericImageView};
use log::debug;
use std::{collections::HashSet, path::PathBuf};
pub(crate) trait Processor {
fn name() -> &'static str
where
Self: Sized;
fn is_processor(s: &str) -> bool
where
Self: Sized;
fn parse(s: &str) -> Option<Box<dyn Processor + Send>>
where
Self: Sized;
fn path(&self, path: PathBuf) -> PathBuf;
fn process(&self, img: DynamicImage) -> Result<DynamicImage, UploadError>;
fn is_whitelisted(whitelist: Option<&HashSet<String>>) -> bool
where
Self: Sized,
{
whitelist
.map(|wl| wl.contains(Self::name()))
.unwrap_or(true)
}
}
pub(crate) struct Identity;
impl Processor for Identity {
fn name() -> &'static str
where
Self: Sized,
{
"identity"
}
fn is_processor(s: &str) -> bool
where
Self: Sized,
{
s == Self::name()
}
fn parse(_: &str) -> Option<Box<dyn Processor + Send>>
where
Self: Sized,
{
Some(Box::new(Identity))
}
fn path(&self, path: PathBuf) -> PathBuf {
path
}
fn process(&self, img: DynamicImage) -> Result<DynamicImage, UploadError> {
Ok(img)
}
}
pub(crate) struct Thumbnail(u32);
impl Processor for Thumbnail {
fn name() -> &'static str
where
Self: Sized,
{
"thumbnail"
}
fn is_processor(s: &str) -> bool
where
Self: Sized,
{
s.starts_with(Self::name())
}
fn parse(s: &str) -> Option<Box<dyn Processor + Send>>
where
Self: Sized,
{
let size = s.trim_start_matches(Self::name()).parse().ok()?;
Some(Box::new(Thumbnail(size)))
}
fn path(&self, mut path: PathBuf) -> PathBuf {
path.push(Self::name());
path.push(self.0.to_string());
path
}
fn process(&self, img: DynamicImage) -> Result<DynamicImage, UploadError> {
if img.in_bounds(self.0, self.0) {
Ok(img.thumbnail(self.0, self.0))
} else {
Ok(img)
}
}
}
pub(crate) struct Blur(f32);
impl Processor for Blur {
fn name() -> &'static str
where
Self: Sized,
{
"blur"
}
fn is_processor(s: &str) -> bool {
s.starts_with(Self::name())
}
fn parse(s: &str) -> Option<Box<dyn Processor + Send>> {
let sigma = s.trim_start_matches(Self::name()).parse().ok()?;
Some(Box::new(Blur(sigma)))
}
fn path(&self, mut path: PathBuf) -> PathBuf {
path.push(Self::name());
path.push(self.0.to_string());
path
}
fn process(&self, img: DynamicImage) -> Result<DynamicImage, UploadError> {
Ok(img.blur(self.0))
}
}
macro_rules! parse {
($x:ident, $y:expr, $z:expr) => {{
if $x::is_processor($y) && $x::is_whitelisted($z) {
return $x::parse($y);
}
}};
}
pub(crate) fn build_chain(
args: &[String],
whitelist: Option<&HashSet<String>>,
) -> Vec<Box<dyn Processor + Send>> {
args.into_iter()
.filter_map(|arg| {
parse!(Identity, arg.as_str(), whitelist);
parse!(Thumbnail, arg.as_str(), whitelist);
parse!(Blur, arg.as_str(), whitelist);
debug!("Skipping {}, invalid or whitelisted", arg);
None
})
.collect()
}
pub(crate) fn build_path(
base: PathBuf,
args: &[Box<dyn Processor + Send>],
filename: String,
) -> PathBuf {
let mut path = args.iter().fold(base, |acc, processor| processor.path(acc));
path.push(filename);
path
}
pub(crate) async fn process_image(
args: Vec<Box<dyn Processor + Send>>,
mut img: DynamicImage,
) -> Result<DynamicImage, UploadError> {
for processor in args.into_iter() {
img = web::block(move || processor.process(img)).await?;
}
Ok(img)
}