chore: Extract assets module out of zed crate. (#3957)

This essentially shaves off about 10% off of an incremental build after
project change and potentially more if you're changing stuff like
`welcome` that's very close to the `zed` crate in the dep graph. That's
because macro expansion takes place even in incremental builds it seems?
And zed (lib) + zed (bin) could take up to 4 seconds out of an
incremental build, which is a *lot* in a 10s build. In reality though it
shaves 1 second off of 5 seconds incremental 'welcome'/ 1s off of 10s
'project' builds.

Note that we had `assets` crate in the past (removed in #2575 /cc
@maxbrunsfeld), but this is a bit different, because `assets` is a
dependency of *just* zed and nothing else. We essentially cache macro
expansion results ourselves.

Release Notes:

- N/A

crates/zed/Cargo.toml

@@ -74,6 +74,7 @@ vim = { path = "../vim" }
 workspace = { path = "../workspace" }
 welcome = { path = "../welcome" }
 zed_actions = {path = "../zed_actions"}
+assets = {path = "../assets"}
 anyhow.workspace = true
 async-compression.workspace = true
 async-tar = "0.4.2"

crates/zed/src/assets.rs

@@ -1,35 +0,0 @@
-use anyhow::anyhow;
-
-use gpui::{AssetSource, Result, SharedString};
-use rust_embed::RustEmbed;
-
-#[derive(RustEmbed)]
-#[folder = "../../assets"]
-#[include = "fonts/**/*"]
-#[include = "icons/**/*"]
-#[include = "themes/**/*"]
-#[exclude = "themes/src/*"]
-#[include = "sounds/**/*"]
-#[include = "*.md"]
-#[exclude = "*.DS_Store"]
-pub struct Assets;
-
-impl AssetSource for Assets {
-    fn load(&self, path: &str) -> Result<std::borrow::Cow<[u8]>> {
-        Self::get(path)
-            .map(|f| f.data)
-            .ok_or_else(|| anyhow!("could not find asset at path \"{}\"", path))
-    }
-
-    fn list(&self, path: &str) -> Result<Vec<SharedString>> {
-        Ok(Self::iter()
-            .filter_map(|p| {
-                if p.starts_with(path) {
-                    Some(p.into())
-                } else {
-                    None
-                }
-            })
-            .collect())
-    }
-}

crates/zed/src/main.rs

@@ -16,6 +16,7 @@ use isahc::{prelude::Configurable, Request};
 use language::LanguageRegistry;
 use log::LevelFilter;
 
+use assets::Assets;
 use node_runtime::RealNodeRuntime;
 use parking_lot::Mutex;
 use serde::{Deserialize, Serialize};
@@ -49,8 +50,8 @@ use welcome::{show_welcome_view, BaseKeymap, FIRST_OPEN};
 use workspace::{AppState, WorkspaceStore};
 use zed::{
     app_menus, build_window_options, ensure_only_instance, handle_cli_connection,
-    handle_keymap_file_changes, initialize_workspace, languages, Assets, IsOnlyInstance,
-    OpenListener, OpenRequest,
+    handle_keymap_file_changes, initialize_workspace, languages, IsOnlyInstance, OpenListener,
+    OpenRequest,
 };
 
 fn main() {

crates/zed/src/zed.rs

@@ -1,11 +1,9 @@
 mod app_menus;
-mod assets;
 pub mod languages;
 mod only_instance;
 mod open_listener;
 
 pub use app_menus::*;
-pub use assets::*;
 use assistant::AssistantPanel;
 use breadcrumbs::Breadcrumbs;
 use collections::VecDeque;
@@ -18,6 +16,7 @@ pub use only_instance::*;
 pub use open_listener::*;
 
 use anyhow::{anyhow, Context as _};
+use assets::Assets;
 use futures::{channel::mpsc, select_biased, StreamExt};
 use project_panel::ProjectPanel;
 use quick_action_bar::QuickActionBar;