perf: use rustc-hash for HashMap and HashSet

Since we already depend on `rustc-hash` transiently, this doesn't add
any more dependencies. As long as DOS attacks aren't a concern (which I
don't think they are?), this should be free performance.

In my (admittedly naive) testing, this really improved CPU usage in some
cases, which is pretty nice to get for free.

Cargo.lock

@@ -1496,6 +1496,7 @@ dependencies = [
  "recently-used-xbel",
  "regex",
  "rust-embed",
+ "rustc-hash 2.1.1",
  "serde",
  "shlex",
  "slotmap",

Cargo.toml

@@ -29,6 +29,7 @@ notify-rust = { version = "4", optional = true }
 open = "5.3.2"
 paste = "1.0"
 regex = "1"
+rustc-hash = "2.1"
 serde = { version = "1", features = ["serde_derive"] }
 shlex = { version = "1.3" }
 tempfile = "3"

src/app.rs

@@ -47,10 +47,11 @@ use notify_debouncer_full::{
     DebouncedEvent, Debouncer, RecommendedCache, new_debouncer,
     notify::{self, RecommendedWatcher},
 };
+use rustc_hash::{FxHashMap, FxHashSet};
 use slotmap::Key as SlotMapKey;
 use std::{
     any::TypeId,
-    collections::{BTreeMap, BTreeSet, HashMap, HashSet, VecDeque},
+    collections::{BTreeMap, BTreeSet, HashMap, VecDeque},
     env, fmt, fs,
     future::Future,
     io,
@@ -67,6 +68,7 @@ use trash::TrashItem;
 use wayland_client::{Proxy, protocol::wl_output::WlOutput};
 
 use crate::{
+    FxOrderMap,
     clipboard::{ClipboardCopy, ClipboardKind, ClipboardPaste},
     config::{
         AppTheme, Config, DesktopConfig, Favorite, IconSizes, TIME_CONFIG_ID, TabConfig,
@@ -654,16 +656,16 @@ pub struct App {
     dialog_pages: DialogPages,
     dialog_text_input: widget::Id,
     key_binds: HashMap<KeyBind, Action>,
-    margin: HashMap<window::Id, (f32, f32, f32, f32)>,
+    margin: FxHashMap<window::Id, (f32, f32, f32, f32)>,
     mime_app_cache: MimeAppCache,
     modifiers: Modifiers,
-    mounter_items: HashMap<MounterKey, MounterItems>,
+    mounter_items: FxHashMap<MounterKey, MounterItems>,
     must_save_sort_names: bool,
     network_drive_connecting: Option<(MounterKey, String)>,
     network_drive_input: String,
     #[cfg(feature = "notify")]
     notification_opt: Option<Arc<Mutex<notify_rust::NotificationHandle>>>,
-    overlap: HashMap<String, (window::Id, Rectangle)>,
+    overlap: FxHashMap<String, (window::Id, Rectangle)>,
     pending_operation_id: u64,
     pending_operations: BTreeMap<u64, (Operation, Controller)>,
     progress_operations: BTreeSet<u64>,
@@ -673,17 +675,17 @@ pub struct App {
     search_id: widget::Id,
     size: Option<Size>,
     #[cfg(all(feature = "wayland", feature = "desktop-applet"))]
-    layer_sizes: HashMap<window::Id, Size>,
+    layer_sizes: FxHashMap<window::Id, Size>,
     #[cfg(all(feature = "wayland", feature = "desktop-applet"))]
-    surface_ids: HashMap<WlOutput, WindowId>,
+    surface_ids: FxHashMap<WlOutput, WindowId>,
     #[cfg(all(feature = "wayland", feature = "desktop-applet"))]
-    surface_names: HashMap<WindowId, String>,
+    surface_names: FxHashMap<WindowId, String>,
     toasts: widget::toaster::Toasts<Message>,
     watcher_opt: Option<(
         Debouncer<RecommendedWatcher, RecommendedCache>,
-        HashSet<PathBuf>,
+        FxHashSet<PathBuf>,
     )>,
-    windows: HashMap<window::Id, WindowKind>,
+    windows: FxHashMap<window::Id, WindowKind>,
     nav_dnd_hover: Option<(Location, Instant)>,
     tab_dnd_hover: Option<(Entity, Instant)>,
     nav_drag_id: DragId,
@@ -699,7 +701,7 @@ impl App {
         // Associate all paths to its MIME type
         // This allows handling paths as groups if possible, such as launching a single video
         // player that is passed every path.
-        let mut groups: HashMap<Mime, Vec<PathBuf>> = HashMap::new();
+        let mut groups: FxHashMap<Mime, Vec<PathBuf>> = FxHashMap::default();
         let mut all_archives = true;
         let supported_archive_types = crate::archive::SUPPORTED_ARCHIVE_TYPES
             .iter()
@@ -915,7 +917,7 @@ impl App {
 
     #[cfg(all(feature = "wayland", feature = "desktop-applet"))]
     fn handle_overlap(&mut self) {
-        let mut overlaps: HashMap<_, _> = self
+        let mut overlaps: FxHashMap<_, _> = self
             .windows
             .keys()
             .map(|k| (*k, (0., 0., 0., 0.)))
@@ -1573,7 +1575,7 @@ impl App {
 
     fn update_watcher(&mut self) -> Task<Message> {
         if let Some((mut watcher, old_paths)) = self.watcher_opt.take() {
-            let mut new_paths = HashSet::new();
+            let mut new_paths = FxHashSet::default();
             for entity in self.tab_model.iter() {
                 if let Some(tab) = self.tab_model.data::<Tab>(entity) {
                     if let Some(path) = tab.location.path_opt() {
@@ -1942,7 +1944,7 @@ impl App {
     fn get_apps_for_mime(&self, mime_type: &Mime) -> Vec<(&MimeApp, MimeAppMatch)> {
         let mut results = Vec::new();
 
-        let mut dedupe = HashSet::new();
+        let mut dedupe = FxHashSet::default();
 
         // start with exact matches
         for mime_app in self.mime_app_cache.get(mime_type) {
@@ -2124,16 +2126,16 @@ impl Application for App {
             dialog_pages: DialogPages::new(),
             dialog_text_input: widget::Id::unique(),
             key_binds,
-            margin: HashMap::new(),
+            margin: FxHashMap::default(),
             mime_app_cache: MimeAppCache::new(),
             modifiers: Modifiers::empty(),
-            mounter_items: HashMap::new(),
+            mounter_items: FxHashMap::default(),
             must_save_sort_names: false,
             network_drive_connecting: None,
             network_drive_input: String::new(),
             #[cfg(feature = "notify")]
             notification_opt: None,
-            overlap: HashMap::new(),
+            overlap: FxHashMap::default(),
             pending_operation_id: 0,
             pending_operations: BTreeMap::new(),
             progress_operations: BTreeSet::new(),
@@ -2143,12 +2145,12 @@ impl Application for App {
             search_id: widget::Id::unique(),
             size: None,
             #[cfg(all(feature = "wayland", feature = "desktop-applet"))]
-            surface_ids: HashMap::new(),
+            surface_ids: FxHashMap::default(),
             #[cfg(all(feature = "wayland", feature = "desktop-applet"))]
-            surface_names: HashMap::new(),
+            surface_names: FxHashMap::default(),
             toasts: widget::toaster::Toasts::new(Message::CloseToast),
             watcher_opt: None,
-            windows: HashMap::new(),
+            windows: FxHashMap::default(),
             nav_dnd_hover: None,
             tab_dnd_hover: None,
             nav_drag_id: DragId::new(),
@@ -2156,7 +2158,7 @@ impl Application for App {
             auto_scroll_speed: None,
             file_dialog_opt: None,
             #[cfg(all(feature = "wayland", feature = "desktop-applet"))]
-            layer_sizes: HashMap::new(),
+            layer_sizes: FxHashMap::default(),
         };
 
         let mut commands = vec![app.update_config()];
@@ -3211,7 +3213,7 @@ impl Application for App {
             Message::NotifyWatcher(mut watcher_wrapper) => match watcher_wrapper.watcher_opt.take()
             {
                 Some(watcher) => {
-                    self.watcher_opt = Some((watcher, HashSet::new()));
+                    self.watcher_opt = Some((watcher, FxHashSet::default()));
                     return self.update_watcher();
                 }
                 None => {
@@ -4678,8 +4680,8 @@ impl Application for App {
             Message::SaveSortNames => {
                 self.must_save_sort_names = false;
                 if let Some(state_handler) = self.state_handler.as_ref() {
-                    if let Err(err) =
+                    if let Err(err) = state_handler
-                        state_handler.set::<ordermap::OrderMap<String, (HeadingOptions, bool)>>(
+                        .set::<FxOrderMap<String, (HeadingOptions, bool)>>(
                             "sort_names",
                             self.state.sort_names.clone(),
                         )

src/config.rs

@@ -8,10 +8,10 @@ use cosmic::{
     iced::Subscription,
     theme,
 };
-use ordermap::OrderMap;
 use serde::{Deserialize, Serialize};
 
 use crate::{
+    FxOrderMap,
     app::App,
     tab::{HeadingOptions, Location, View},
 };
@@ -115,13 +115,13 @@ pub enum TypeToSearch {
 #[derive(Clone, CosmicConfigEntry, Debug, Deserialize, Eq, PartialEq, Serialize)]
 #[serde(default)]
 pub struct State {
-    pub sort_names: ordermap::OrderMap<String, (HeadingOptions, bool)>,
+    pub sort_names: FxOrderMap<String, (HeadingOptions, bool)>,
 }
 
 impl Default for State {
     fn default() -> Self {
         Self {
-            sort_names: OrderMap::from_iter(dirs::download_dir().into_iter().map(|dir| {
+            sort_names: FxOrderMap::from_iter(dirs::download_dir().into_iter().map(|dir| {
                 (
                     Location::Path(dir).normalize().to_string(),
                     (HeadingOptions::Modified, false),

src/dialog.rs

@@ -25,9 +25,10 @@ use notify_debouncer_full::{
     notify::{self, RecommendedWatcher},
 };
 use recently_used_xbel::update_recently_used;
+use rustc_hash::{FxHashMap, FxHashSet};
 use std::{
     any::TypeId,
-    collections::{HashMap, HashSet, VecDeque},
+    collections::{HashMap, VecDeque},
     env, fmt, fs,
     num::NonZeroU16,
     path::PathBuf,
@@ -509,7 +510,7 @@ struct App {
     filter_selected: Option<usize>,
     filename_id: widget::Id,
     modifiers: Modifiers,
-    mounter_items: HashMap<MounterKey, MounterItems>,
+    mounter_items: FxHashMap<MounterKey, MounterItems>,
     nav_model: segmented_button::SingleSelectModel,
     result_opt: Option<DialogResult>,
     search_id: widget::Id,
@@ -517,7 +518,7 @@ struct App {
     key_binds: HashMap<KeyBind, Action>,
     watcher_opt: Option<(
         Debouncer<RecommendedWatcher, RecommendedCache>,
-        HashSet<PathBuf>,
+        FxHashSet<PathBuf>,
     )>,
     auto_scroll_speed: Option<i16>,
 }
@@ -871,7 +872,7 @@ impl App {
 
     fn update_watcher(&mut self) -> Task<Message> {
         if let Some((mut watcher, old_paths)) = self.watcher_opt.take() {
-            let mut new_paths = HashSet::new();
+            let mut new_paths = FxHashSet::default();
             if let Some(path) = &self.tab.location.path_opt() {
                 new_paths.insert(path.to_path_buf());
             }
@@ -981,7 +982,7 @@ impl Application for App {
             filter_selected: None,
             filename_id: widget::Id::unique(),
             modifiers: Modifiers::empty(),
-            mounter_items: HashMap::new(),
+            mounter_items: FxHashMap::default(),
             nav_model: segmented_button::ModelBuilder::default().build(),
             result_opt: None,
             search_id: widget::Id::unique(),
@@ -1519,7 +1520,7 @@ impl Application for App {
             Message::NotifyWatcher(mut watcher_wrapper) => match watcher_wrapper.watcher_opt.take()
             {
                 Some(watcher) => {
-                    self.watcher_opt = Some((watcher, HashSet::new()));
+                    self.watcher_opt = Some((watcher, FxHashSet::default()));
                     return self.update_watcher();
                 }
                 None => {

src/lib.rs

@@ -27,6 +27,8 @@ pub mod tab;
 mod thumbnail_cacher;
 mod thumbnailer;
 
+pub(crate) type FxOrderMap<K, V> = ordermap::OrderMap<K, V, rustc_hash::FxBuildHasher>;
+
 pub(crate) fn err_str<T: ToString>(err: T) -> String {
     err.to_string()
 }

src/mime_app.rs

@@ -5,9 +5,9 @@
 use cosmic::desktop;
 use cosmic::widget;
 pub use mime_guess::Mime;
+use rustc_hash::FxHashMap;
 use std::{
     cmp::Ordering,
-    collections::HashMap,
     env,
     ffi::OsStr,
     fs, io,
@@ -221,8 +221,8 @@ fn filename_eq(path_opt: &Option<PathBuf>, filename: &str) -> bool {
 
 pub struct MimeAppCache {
     apps: Vec<MimeApp>,
-    cache: HashMap<Mime, Vec<MimeApp>>,
+    cache: FxHashMap<Mime, Vec<MimeApp>>,
-    icons: HashMap<Mime, Vec<widget::icon::Handle>>,
+    icons: FxHashMap<Mime, Vec<widget::icon::Handle>>,
     terminals: Vec<MimeApp>,
 }
 
@@ -230,8 +230,8 @@ impl MimeAppCache {
     pub fn new() -> Self {
         let mut mime_app_cache = Self {
             apps: Vec::new(),
-            cache: HashMap::new(),
+            cache: FxHashMap::default(),
-            icons: HashMap::new(),
+            icons: FxHashMap::default(),
             terminals: Vec::new(),
         };
         mime_app_cache.reload();

src/mime_icon.rs

@@ -2,8 +2,8 @@
 
 use cosmic::widget::icon;
 use mime_guess::Mime;
+use rustc_hash::FxHashMap;
 use std::{
-    collections::HashMap,
     fs,
     path::Path,
     sync::{LazyLock, Mutex},
@@ -18,14 +18,14 @@ struct MimeIconKey {
 }
 
 struct MimeIconCache {
-    cache: HashMap<MimeIconKey, Option<icon::Handle>>,
+    cache: FxHashMap<MimeIconKey, Option<icon::Handle>>,
     shared_mime_info: xdg_mime::SharedMimeInfo,
 }
 
 impl MimeIconCache {
     pub fn new() -> Self {
         Self {
-            cache: HashMap::new(),
+            cache: FxHashMap::default(),
             shared_mime_info: xdg_mime::SharedMimeInfo::new(),
         }
     }

src/tab.rs

@@ -49,7 +49,7 @@ use icu::{
 use image::ImageDecoder;
 use jxl_oxide::integration::JxlDecoder;
 use mime_guess::{Mime, mime};
-use ordermap::OrderMap;
+use rustc_hash::FxHashMap;
 use serde::{Deserialize, Serialize};
 use std::{
     borrow::Cow,
@@ -73,6 +73,7 @@ use trash::TrashItemSize;
 use walkdir::WalkDir;
 
 use crate::{
+    FxOrderMap,
     app::{Action, PreviewItem, PreviewKind},
     clipboard::{ClipboardCopy, ClipboardKind, ClipboardPaste},
     config::{DesktopConfig, ICON_SCALE_MAX, ICON_SIZE_GRID, IconSizes, TabConfig, ThumbCfg},
@@ -100,9 +101,9 @@ const THUMBNAIL_SIZE: u32 = (ICON_SIZE_GRID as u32) * (ICON_SCALE_MAX as u32);
 pub static THUMB_SEMAPHORE: LazyLock<tokio::sync::Semaphore> =
     LazyLock::new(|| tokio::sync::Semaphore::const_new(num_cpus::get()));
 
-pub(crate) static SORT_OPTION_FALLBACK: LazyLock<HashMap<String, (HeadingOptions, bool)>> =
+pub(crate) static SORT_OPTION_FALLBACK: LazyLock<FxHashMap<String, (HeadingOptions, bool)>> =
     LazyLock::new(|| {
-        HashMap::from_iter(dirs::download_dir().into_iter().map(|dir| {
+        FxHashMap::from_iter(dirs::download_dir().into_iter().map(|dir| {
             (
                 Location::Path(dir).normalize().to_string(),
                 (HeadingOptions::Modified, false),
@@ -131,8 +132,8 @@ static MODE_NAMES: LazyLock<Vec<String>> = LazyLock::new(|| {
     ]
 });
 
-static SPECIAL_DIRS: LazyLock<HashMap<PathBuf, &'static str>> = LazyLock::new(|| {
+static SPECIAL_DIRS: LazyLock<FxHashMap<PathBuf, &'static str>> = LazyLock::new(|| {
-    let mut special_dirs = HashMap::new();
+    let mut special_dirs = FxHashMap::default();
     if let Some(dir) = dirs::document_dir() {
         special_dirs.insert(dir, "folder-documents");
     }
@@ -534,25 +535,17 @@ pub enum FsKind {
 pub fn fs_kind(metadata: &Metadata) -> FsKind {
     //TODO: method to reload remote filesystems dynamically
     //TODO: fix for https://github.com/eminence/procfs/issues/262
-    static DEVICES: LazyLock<HashMap<u64, FsKind>> = LazyLock::new(|| {
+    static DEVICES: LazyLock<FxHashMap<u64, FsKind>> = LazyLock::new(|| {
-        let mut devices = HashMap::new();
+        let mut devices = FxHashMap::default();
         match procfs::process::Process::myself() {
             Ok(process) => match process.mountinfo() {
                 Ok(mount_infos) => {
-                    for mount_info in mount_infos.iter() {
+                    devices = FxHashMap::from_iter(mount_infos.iter().filter_map(|mount_info| {
                         let mut parts = mount_info.majmin.split(':');
-                        let Some(major_str) = parts.next() else {
+                        let major_str = parts.next()?;
-                            continue;
+                        let minor_str = parts.next()?;
-                        };
+                        let major = major_str.parse::<libc::c_uint>().ok()?;
-                        let Some(minor_str) = parts.next() else {
+                        let minor = minor_str.parse::<libc::c_uint>().ok()?;
-                            continue;
-                        };
-                        let Ok(major) = major_str.parse::<libc::c_uint>() else {
-                            continue;
-                        };
-                        let Ok(minor) = minor_str.parse::<libc::c_uint>() else {
-                            continue;
-                        };
                         let dev = libc::makedev(major, minor);
                         //TODO: make sure this list is exhaustive
                         let kind = match mount_info.fs_type.as_str() {
@@ -561,8 +554,8 @@ pub fn fs_kind(metadata: &Metadata) -> FsKind {
                             "fuse.gvfsd-fuse" => FsKind::Gvfs,
                             _ => FsKind::Local,
                         };
-                        devices.insert(dev, kind);
+                        Some((dev, kind))
-                    }
+                    }));
                 }
                 Err(err) => {
                     log::warn!("failed to get mount info: {err}");
@@ -2525,7 +2518,7 @@ impl Tab {
         location: Location,
         config: TabConfig,
         thumb_config: ThumbCfg,
-        sorting_options: Option<&OrderMap<String, (HeadingOptions, bool)>>,
+        sorting_options: Option<&FxOrderMap<String, (HeadingOptions, bool)>>,
         scrollable_id: widget::Id,
         window_id: Option<window::Id>,
     ) -> Self {

src/thumbnail_cacher.rs

@@ -1,7 +1,7 @@
 use image::DynamicImage;
 use md5::{Digest, Md5};
+use rustc_hash::FxHashMap;
 use std::{
-    collections::HashMap,
     error::Error,
     fs::{self, File},
     io::{self, BufReader, BufWriter},
@@ -143,7 +143,7 @@ impl ThumbnailCacher {
         let mut reader = decoder.read_info()?;
         let (width, height, color_type, bit_depth, mut text_chunks) = {
             let info = reader.info();
-            let text_chunks: HashMap<String, String> = info
+            let text_chunks: FxHashMap<String, String> = info
                 .uncompressed_latin1_text
                 .clone()
                 .into_iter()

src/thumbnailer.rs

@@ -2,8 +2,8 @@
 // SPDX-License-Identifier: GPL-3.0-only
 
 use mime_guess::Mime;
+use rustc_hash::FxHashMap;
 use std::{
-    collections::HashMap,
     fs,
     path::Path,
     process,
@@ -56,13 +56,13 @@ impl Thumbnailer {
 }
 
 pub struct ThumbnailerCache {
-    cache: HashMap<Mime, Vec<Thumbnailer>>,
+    cache: FxHashMap<Mime, Vec<Thumbnailer>>,
 }
 
 impl ThumbnailerCache {
     pub fn new() -> Self {
         let mut thumbnailer_cache = Self {
-            cache: HashMap::new(),
+            cache: FxHashMap::default(),
         };
         thumbnailer_cache.reload();
         thumbnailer_cache