profile picture image cache

coding from a plane so this is helping alot with PFPs

src/imgcache.rs

@@ -0,0 +1,57 @@
+use crate::{Error, Result};
+use egui::TextureHandle;
+use poll_promise::Promise;
+
+use egui::ColorImage;
+use hex;
+use std::borrow::Cow;
+use std::collections::hash_map::Entry;
+use std::collections::HashMap;
+use std::fs::File;
+use std::hash::{Hash, Hasher};
+use std::io;
+use std::path;
+use tokio::fs;
+
+pub type ImageCacheValue = Promise<Result<TextureHandle>>;
+pub type ImageCacheMap = HashMap<String, ImageCacheValue>;
+
+pub struct ImageCache {
+    pub cache_dir: path::PathBuf,
+    url_imgs: ImageCacheMap,
+}
+
+impl ImageCache {
+    pub fn new(cache_dir: path::PathBuf) -> Self {
+        Self {
+            cache_dir,
+            url_imgs: HashMap::new(),
+        }
+    }
+
+    pub fn write(cache_dir: &path::Path, url: &str, data: ColorImage) -> Result<()> {
+        let file_path = cache_dir.join(&Self::key(url));
+        let file = File::options().write(true).create(true).open(file_path)?;
+        let encoder = image::codecs::webp::WebPEncoder::new_lossless(file);
+        encoder.encode(
+            data.as_raw(),
+            data.size[0] as u32,
+            data.size[1] as u32,
+            image::ColorType::Rgba8,
+        );
+
+        Ok(())
+    }
+
+    pub fn key(url: &str) -> String {
+        base32::encode(base32::Alphabet::Crockford, url.as_bytes())
+    }
+
+    pub fn map(&self) -> &ImageCacheMap {
+        &self.url_imgs
+    }
+
+    pub fn map_mut(&mut self) -> &mut ImageCacheMap {
+        &mut self.url_imgs
+    }
+}