transition to nucleo for fuzzy matching (helix-editor#7814)

* transition to nucleo for fuzzy matching

* drop flakey test case

since the picker streams in results now any test that relies
on the picker containing results is potentially flakely

* use crates.io version of nucleo

* Fix typo in commands.rs

Co-authored-by: Skyler Hawthorne <skyler@dead10ck.com>

---------

Co-authored-by: Skyler Hawthorne <skyler@dead10ck.com>

Cargo.toml

@@ -5,6 +5,7 @@ members = [
   "helix-term",
   "helix-tui",
   "helix-lsp",
+  "helix-event",
   "helix-dap",
   "helix-loader",
   "helix-vcs",
@@ -35,3 +36,4 @@ package.helix-term.opt-level = 2
 
 [workspace.dependencies]
 tree-sitter = { version = "0.20", git = "https://github.com/tree-sitter/tree-sitter", rev = "ab09ae20d640711174b8da8a654f6b3dec93da1a" }
+nucleo = "0.2.0"

helix-core/Cargo.toml

@@ -48,6 +48,9 @@ chrono = { version = "0.4", default-features = false, features = ["alloc", "std"
 etcetera = "0.8"
 textwrap = "0.16.0"
 
+nucleo.workspace = true
+parking_lot = "0.12"
+
 [dev-dependencies]
 quickcheck = { version = "1", default-features = false }
 indoc = "2.0.3"

helix-core/src/fuzzy.rs

@@ -0,0 +1,43 @@
+use std::ops::DerefMut;
+
+use nucleo::pattern::{AtomKind, CaseMatching, Pattern};
+use nucleo::Config;
+use parking_lot::Mutex;
+
+pub struct LazyMutex<T> {
+    inner: Mutex<Option<T>>,
+    init: fn() -> T,
+}
+
+impl<T> LazyMutex<T> {
+    pub const fn new(init: fn() -> T) -> Self {
+        Self {
+            inner: Mutex::new(None),
+            init,
+        }
+    }
+
+    pub fn lock(&self) -> impl DerefMut<Target = T> + '_ {
+        parking_lot::MutexGuard::map(self.inner.lock(), |val| val.get_or_insert_with(self.init))
+    }
+}
+
+pub static MATCHER: LazyMutex<nucleo::Matcher> = LazyMutex::new(nucleo::Matcher::default);
+
+/// convenience function to easily fuzzy match
+/// on a (relatively small list of inputs). This is not recommended for building a full tui
+/// application that can match large numbers of matches as all matching is done on the current
+/// thread, effectively blocking the UI
+pub fn fuzzy_match<T: AsRef<str>>(
+    pattern: &str,
+    items: impl IntoIterator<Item = T>,
+    path: bool,
+) -> Vec<(T, u32)> {
+    let mut matcher = MATCHER.lock();
+    matcher.config = Config::DEFAULT;
+    if path {
+        matcher.config.set_match_paths();
+    }
+    let pattern = Pattern::new(pattern, CaseMatching::Smart, AtomKind::Fuzzy);
+    pattern.match_list(items, &mut matcher)
+}

helix-core/src/lib.rs

@@ -7,6 +7,7 @@ pub mod config;
 pub mod diagnostic;
 pub mod diff;
 pub mod doc_formatter;
+pub mod fuzzy;
 pub mod graphemes;
 pub mod history;
 pub mod increment;

helix-event/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "helix-event"
+version = "0.6.0"
+authors = ["Blaž Hrastnik <blaz@mxxn.io>"]
+edition = "2021"
+license = "MPL-2.0"
+categories = ["editor"]
+repository = "https://github.com/helix-editor/helix"
+homepage = "https://helix-editor.com"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+tokio = { version = "1", features = ["rt", "rt-multi-thread", "time", "sync", "parking_lot"] }
+parking_lot = { version = "0.12", features = ["send_guard"] }

helix-event/src/lib.rs

@@ -0,0 +1,8 @@
+//! `helix-event` contains systems that allow (often async) communication between
+//! different editor components without strongly coupling them. Currently this
+//! crate only contains some smaller facilities but the intend is to add more
+//! functionality in the future ( like a generic hook system)
+
+pub use redraw::{lock_frame, redraw_requested, request_redraw, start_frame, RenderLockGuard};
+
+mod redraw;

helix-event/src/redraw.rs

@@ -0,0 +1,49 @@
+//! Signals that control when/if the editor redraws
+
+use std::future::Future;
+
+use parking_lot::{RwLock, RwLockReadGuard};
+use tokio::sync::Notify;
+
+/// A `Notify` instance that can be used to (asynchronously) request
+/// the editor the render a new frame.
+static REDRAW_NOTIFY: Notify = Notify::const_new();
+
+/// A `RwLock` that prevents the next frame from being
+/// drawn until an exclusive (write) lock can be acquired.
+/// This allows asynchsonous tasks to acquire `non-exclusive`
+/// locks (read) to prevent the next frame from being drawn
+/// until a certain computation has finished.
+static RENDER_LOCK: RwLock<()> = RwLock::new(());
+
+pub type RenderLockGuard = RwLockReadGuard<'static, ()>;
+
+/// Requests that the editor is redrawn. The redraws are debounced (currently to
+/// 30FPS) so this can be called many times without causing a ton of frames to
+/// be rendered.
+pub fn request_redraw() {
+    REDRAW_NOTIFY.notify_one();
+}
+
+/// Returns a future that will yield once a redraw has been asynchronously
+/// requested using [`request_redraw`].
+pub fn redraw_requested() -> impl Future<Output = ()> {
+    REDRAW_NOTIFY.notified()
+}
+
+/// Wait until all locks acquired with [`lock_frame`] have been released.
+/// This function is called before rendering and is intended to allow the frame
+/// to wait for async computations that should be included in the current frame.
+pub fn start_frame() {
+    drop(RENDER_LOCK.write());
+    // exhaust any leftover redraw notifications
+    let notify = REDRAW_NOTIFY.notified();
+    tokio::pin!(notify);
+    notify.enable();
+}
+
+/// Acquires the render lock which will prevent the next frame from being drawn
+/// until the returned guard is dropped.
+pub fn lock_frame() -> RenderLockGuard {
+    RENDER_LOCK.read()
+}

helix-term/Cargo.toml

@@ -24,6 +24,7 @@ path = "src/main.rs"
 
 [dependencies]
 helix-core = { version = "0.6", path = "../helix-core" }
+helix-event = { version = "0.6", path = "../helix-event" }
 helix-view = { version = "0.6", path = "../helix-view" }
 helix-lsp = { version = "0.6", path = "../helix-lsp" }
 helix-dap = { version = "0.6", path = "../helix-dap" }
@@ -49,7 +50,7 @@ chrono = { version = "0.4", default-features = false, features = ["clock"] }
 log = "0.4"
 
 # File picker
-fuzzy-matcher = "0.3"
+nucleo.workspace = true
 ignore = "0.4"
 # markdown doc rendering
 pulldown-cmark = { version = "0.9", default-features = false }