Cache fonts

src/buffer.rs

@@ -829,8 +829,8 @@ impl<'a> TextBuffer<'a> {
                             "{}, {}: '{}' ('{}'): '{}' ({:?})",
                             self.cursor.line.get(),
                             self.cursor.index,
-                            font_opt.map_or("?", |font| font.info.family.as_str()),
-                            font_opt.map_or("?", |font| font.info.post_script_name.as_str()),
+                            font_opt.as_ref().map_or("?", |font| font.info.family.as_str()),
+                            font_opt.as_ref().map_or("?", |font| font.info.post_script_name.as_str()),
                             text_glyph,
                             text_glyph
                         );

src/font/fallback/mod.rs

@@ -1,8 +1,9 @@
 // SPDX-License-Identifier: MIT OR Apache-2.0
 
+use std::sync::Arc;
 use unicode_script::Script;
 
-use super::Font;
+use crate::Font;
 
 use self::platform::*;
 
@@ -27,7 +28,7 @@ mod platform;
 mod platform;
 
 pub struct FontFallbackIter<'a> {
-    fonts: &'a [Font<'a>],
+    fonts: &'a [Arc<Font<'a>>],
     default_families: &'a [&'a str],
     default_i: usize,
     scripts: Vec<Script>,
@@ -39,7 +40,12 @@ pub struct FontFallbackIter<'a> {
 }
 
 impl<'a> FontFallbackIter<'a> {
-    pub fn new(fonts: &'a [Font<'a>], default_families: &'a [&'a str], scripts: Vec<Script>, locale: &'a str) -> Self {
+    pub fn new(
+        fonts: &'a [Arc<Font<'a>>],
+        default_families: &'a [&'a str],
+        scripts: Vec<Script>,
+        locale: &'a str
+    ) -> Self {
         Self {
             fonts,
             default_families,
@@ -84,7 +90,7 @@ impl<'a> FontFallbackIter<'a> {
 }
 
 impl<'a> Iterator for FontFallbackIter<'a> {
-    type Item = &'a Font<'a>;
+    type Item = &'a Arc<Font<'a>>;
     fn next(&mut self) -> Option<Self::Item> {
         while self.default_i < self.default_families.len() {
             let default_family = self.default_families[self.default_i];

src/font/matches.rs

@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: MIT OR Apache-2.0
 
+use std::sync::Arc;
 use unicode_script::{Script, UnicodeScript};
 
 use super::{Font, FontShapeGlyph, FontShapeLine, FontShapeSpan, FontShapeWord};
@@ -8,13 +9,13 @@ use super::fallback::{FontFallbackIter};
 /// Fonts that match a pattern
 pub struct FontMatches<'a> {
     pub locale: &'a str,
-    pub fonts: Vec<Font<'a>>,
+    pub fonts: Vec<Arc<Font<'a>>>,
 }
 
 impl<'a> FontMatches<'a> {
     fn shape_fallback(
         &self,
-        font: &'a Font<'a>,
+        font: &Font<'a>,
         line: &str,
         start_word: usize,
         end_word: usize,

src/font/system.rs

@@ -1,14 +1,20 @@
 // SPDX-License-Identifier: MIT OR Apache-2.0
 
+use std::{
+    collections::HashMap,
+    sync::{Arc, Mutex},
+};
+
 use crate::{Attrs, Font, FontMatches};
 
 /// Access system fonts
-pub struct FontSystem {
+pub struct FontSystem<'a> {
     pub locale: String,
     db: fontdb::Database,
+    pub font_cache: Mutex<HashMap<fontdb::ID, Option<Arc<Font<'a>>>>>,
 }
 
-impl FontSystem {
+impl<'a> FontSystem<'a> {
     pub fn new() -> Self {
         let locale = sys_locale::get_locale().unwrap_or_else(|| {
             log::warn!("failed to get system locale, falling back to en-US");
@@ -50,11 +56,29 @@ impl FontSystem {
             );
         }
 
-        Self { locale, db }
+        Self {
+            locale,
+            db,
+            font_cache: Mutex::new(HashMap::new()),
+        }
+    }
+
+    pub fn get_font(&'a self, id: fontdb::ID) -> Option<Arc<Font<'a>>> {
+        let mut font_cache = self.font_cache.lock().unwrap();
+        font_cache.entry(id).or_insert_with(|| {
+            let face = self.db.face(id)?;
+            match Font::new(face) {
+                Some(font) => Some(Arc::new(font)),
+                None => {
+                    log::warn!("failed to load font '{}'", face.post_script_name);
+                    None
+                }
+            }
+        }).clone()
     }
 
     pub fn matches<F: Fn(&fontdb::FaceInfo) -> bool>(
-        &self,
+        &'a self,
         f: F,
     ) -> Option<FontMatches<'_>> {
         let mut fonts = Vec::new();
@@ -63,11 +87,9 @@ impl FontSystem {
                 continue;
             }
 
-            match Font::new(face) {
+            match self.get_font(face.id) {
                 Some(font) => fonts.push(font),
-                None => {
-                    log::warn!("failed to load font '{}'", face.post_script_name);
-                }
+                None => (),
             }
         }
 
@@ -81,7 +103,7 @@ impl FontSystem {
         }
     }
 
-    pub fn matches_attrs(&self, attrs: Attrs) -> Option<FontMatches<'_>> {
+    pub fn matches_attrs(&'a self, attrs: Attrs) -> Option<FontMatches<'_>> {
         self.matches(|info| {
             let matched = {
                 info.style == attrs.style &&
@@ -108,9 +130,3 @@ impl FontSystem {
         })
     }
 }
-
-impl Default for FontSystem {
-    fn default() -> Self {
-        Self::new()
-    }
-}