Move all crates to a top-level crates folder

Co-Authored-By: Max Brunsfeld <maxbrunsfeld@gmail.com>

crates/gpui/src/assets.rs

@@ -0,0 +1,46 @@
+use anyhow::{anyhow, Result};
+use std::{borrow::Cow, cell::RefCell, collections::HashMap};
+
+pub trait AssetSource: 'static + Send + Sync {
+    fn load(&self, path: &str) -> Result<Cow<[u8]>>;
+    fn list(&self, path: &str) -> Vec<Cow<'static, str>>;
+}
+
+impl AssetSource for () {
+    fn load(&self, path: &str) -> Result<Cow<[u8]>> {
+        Err(anyhow!(
+            "get called on empty asset provider with \"{}\"",
+            path
+        ))
+    }
+
+    fn list(&self, _: &str) -> Vec<Cow<'static, str>> {
+        vec![]
+    }
+}
+
+pub struct AssetCache {
+    source: Box<dyn AssetSource>,
+    svgs: RefCell<HashMap<String, usvg::Tree>>,
+}
+
+impl AssetCache {
+    pub fn new(source: impl AssetSource) -> Self {
+        Self {
+            source: Box::new(source),
+            svgs: RefCell::new(HashMap::new()),
+        }
+    }
+
+    pub fn svg(&self, path: &str) -> Result<usvg::Tree> {
+        let mut svgs = self.svgs.borrow_mut();
+        if let Some(svg) = svgs.get(path) {
+            Ok(svg.clone())
+        } else {
+            let bytes = self.source.load(path)?;
+            let svg = usvg::Tree::from_data(&bytes, &usvg::Options::default())?;
+            svgs.insert(path.to_string(), svg.clone());
+            Ok(svg)
+        }
+    }
+}