refactor(config): improve safety and efficiency of CosmicTk config

src/config/mod.rs

@@ -8,7 +8,25 @@ use cosmic_config::cosmic_config_derive::CosmicConfigEntry;
 use cosmic_config::{Config, CosmicConfigEntry};
 use serde::{Deserialize, Serialize};
 use std::collections::BTreeSet;
-use std::sync::{LazyLock, Mutex, RwLock};
+use std::sync::{Arc, LazyLock, Mutex, PoisonError, RwLock, RwLockReadGuard};
+
+/// ID for the `CosmicTk` config.
+pub const ID: &str = "com.system76.CosmicTk";
+
+const MONO_FAMILY_DEFAULT: &str = "Noto Sans Mono";
+const SANS_FAMILY_DEFAULT: &str = "Open Sans";
+
+// Copyright 2024 System76 <info@system76.com>
+// SPDX-License-Identifier: MPL-2.0
+
+//! Configurations available to libcosmic applications.
+
+use crate::cosmic_theme::Density;
+use cosmic_config::cosmic_config_derive::CosmicConfigEntry;
+use cosmic_config::{Config, CosmicConfigEntry};
+use serde::{Deserialize, Serialize};
+use std::collections::BTreeSet;
+use std::sync::{LazyLock, Mutex, RwLock, RwLockReadGuard, Arc, PoisonError};
 
 /// ID for the `CosmicTk` config.
 pub const ID: &str = "com.system76.CosmicTk";
@@ -17,18 +35,17 @@ const MONO_FAMILY_DEFAULT: &str = "Noto Sans Mono";
 const SANS_FAMILY_DEFAULT: &str = "Open Sans";
 
 /// Stores static strings of the family names for `iced::Font` compatibility.
-pub static FAMILY_MAP: LazyLock<Mutex<BTreeSet<&'static str>>> = LazyLock::new(Mutex::default);
+pub static FAMILY_MAP: LazyLock<Mutex<BTreeSet<Arc<str>>>> =
+    LazyLock::new(|| Mutex::new(BTreeSet::new()));
 
 pub static COSMIC_TK: LazyLock<RwLock<CosmicTk>> = LazyLock::new(|| {
     RwLock::new(
-        CosmicTk::config()
+        CosmicTk::config().map(|c| {
-            .map(|c| {
             CosmicTk::get_entry(&c).unwrap_or_else(|(errors, mode)| {
                 for why in errors.into_iter().filter(cosmic_config::Error::is_err) {
                     if let cosmic_config::Error::GetKey(_, err) = &why {
                                          if err.kind() == std::io::ErrorKind::NotFound {
-                                // No system default config installed; don't error
+                                             continue; // No system default config installed
-                                continue;
                                          }
                                      }
                                      tracing::error!(?why, "CosmicTk config entry error");
@@ -38,79 +55,63 @@ pub static COSMIC_TK: LazyLock<RwLock<CosmicTk>> = LazyLock::new(|| {
                          })
                          .unwrap_or_default(),
                  )
-});
+             });
+
+/// Helper to handle poisoned locks and reduce repetitive `.read().unwrap()`.
+fn cosmic() -> RwLockReadGuard<'static, CosmicTk> {
+    COSMIC_TK.read().unwrap_or_else(|e| e.into_inner())
+}
 
 /// Apply the theme to other toolkits.
-#[allow(clippy::missing_panics_doc)]
 pub fn apply_theme_global() -> bool {
-    COSMIC_TK.read().unwrap().apply_theme_global
+    cosmic().apply_theme_global
 }
 
 /// Show minimize button in window header.
-#[allow(clippy::missing_panics_doc)]
 pub fn show_minimize() -> bool {
-    COSMIC_TK.read().unwrap().show_minimize
+    cosmic().show_minimize
 }
 
 /// Show maximize button in window header.
-#[allow(clippy::missing_panics_doc)]
 pub fn show_maximize() -> bool {
-    COSMIC_TK.read().unwrap().show_maximize
+    cosmic().show_maximize
 }
 
 /// Preferred icon theme.
-#[allow(clippy::missing_panics_doc)]
+pub fn icon_theme() -> &str {
-pub fn icon_theme() -> String {
+    &cosmic().icon_theme
-    COSMIC_TK.read().unwrap().icon_theme.clone()
 }
 
 /// Density of CSD/SSD header bars.
-#[allow(clippy::missing_panics_doc)]
 pub fn header_size() -> Density {
-    COSMIC_TK.read().unwrap().header_size
+    cosmic().header_size
 }
 
 /// Interface density.
-#[allow(clippy::missing_panics_doc)]
 pub fn interface_density() -> Density {
-    COSMIC_TK.read().unwrap().interface_density
+    cosmic().interface_density
 }
 
-#[allow(clippy::missing_panics_doc)]
+/// Interface font.
-pub fn interface_font() -> FontConfig {
+pub fn interface_font() -> &FontConfig {
-    COSMIC_TK.read().unwrap().interface_font.clone()
+    &cosmic().interface_font
 }
 
-#[allow(clippy::missing_panics_doc)]
+/// Monospace font.
-pub fn monospace_font() -> FontConfig {
+pub fn monospace_font() -> &FontConfig {
-    COSMIC_TK.read().unwrap().monospace_font.clone()
+    &cosmic().monospace_font
 }
 
 #[derive(Clone, CosmicConfigEntry, Debug, Eq, PartialEq)]
 #[version = 1]
 pub struct CosmicTk {
-    /// Apply the theme to other toolkits.
     pub apply_theme_global: bool,
-
-    /// Show minimize button in window header.
     pub show_minimize: bool,
-
-    /// Show maximize button in window header.
     pub show_maximize: bool,
-
-    /// Preferred icon theme.
     pub icon_theme: String,
-
-    /// Density of CSD/SSD header bars.
     pub header_size: Density,
-
-    /// Interface density.
     pub interface_density: Density,
-
-    /// Interface font family
     pub interface_font: FontConfig,
-
-    /// Mono font family
     pub monospace_font: FontConfig,
 }
 
@@ -156,19 +157,19 @@ pub struct FontConfig {
 
 impl From<FontConfig> for iced::Font {
     fn from(font: FontConfig) -> Self {
-        let mut family_map = FAMILY_MAP.lock().unwrap();
+        let mut family_map = FAMILY_MAP.lock().unwrap_or_else(|e| e.into_inner());
 
-        let name: &'static str = family_map
+        let name: Arc<str> = family_map
-            .get(font.family.as_str())
+            .get(&font.family.as_str().into())
-            .copied()
+            .cloned()
             .unwrap_or_else(|| {
-                let value = font.family.clone().leak();
+                let value: Arc<str> = Arc::from(font.family.clone());
-                family_map.insert(value);
+                family_map.insert(Arc::clone(&value));
                 value
             });
 
         Self {
-            family: iced::font::Family::Name(name),
+            family: iced::font::Family::Name(Box::leak(name.clone().into_boxed_str())),
             weight: font.weight,
             stretch: font.stretch,
             style: font.style,