1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171

// SPDX-License-Identifier: MIT OR Apache-2.0

use std::{
    collections::HashMap,
    sync::{Arc, Mutex},
};

use crate::{Attrs, AttrsOwned, Font, FontMatches};

#[ouroboros::self_referencing]
struct FontSystemInner {
    locale: String,
    db: fontdb::Database,
    #[borrows(db)]
    #[not_covariant]
    font_cache: Mutex<HashMap<fontdb::ID, Option<Arc<Font<'this>>>>>,
    #[borrows(locale, db)]
    #[not_covariant]
    font_matches_cache: Mutex<HashMap<AttrsOwned, Arc<FontMatches<'this>>>>,
}

/// Access system fonts
pub struct FontSystem(FontSystemInner);

impl FontSystem {
    /// Create a new [`FontSystem`], that allows access to any installed system fonts
    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");
            String::from("en-US")
        });
        log::debug!("Locale: {}", locale);

        let mut db = fontdb::Database::new();
        {
            #[cfg(not(target_arch = "wasm32"))]
            let now = std::time::Instant::now();

            db.load_system_fonts();
            //TODO: configurable default fonts
            db.set_monospace_family("Fira Mono");
            db.set_sans_serif_family("Fira Sans");
            db.set_serif_family("DejaVu Serif");

            #[cfg(not(target_arch = "wasm32"))]
            log::info!(
                "Parsed {} font faces in {}ms.",
                db.len(),
                now.elapsed().as_millis()
            );
        }

        Self::new_with_locale_and_db(locale, db)
    }

    /// Create a new [`FontSystem`], manually specifying the current locale and font database.
    pub fn new_with_locale_and_db(locale: String, mut db: fontdb::Database) -> Self {
        {
            #[cfg(not(target_arch = "wasm32"))]
            let now = std::time::Instant::now();

            //TODO only do this on demand!
            for i in 0..db.faces().len() {
                let id = db.faces()[i].id;
                unsafe {
                    db.make_shared_face_data(id);
                }
            }

            #[cfg(not(target_arch = "wasm32"))]
            log::info!(
                "Mapped {} font faces in {}ms.",
                db.len(),
                now.elapsed().as_millis()
            );
        }

        Self(
            FontSystemInnerBuilder {
                locale,
                db,
                font_cache_builder: |_| Mutex::new(HashMap::new()),
                font_matches_cache_builder: |_, _| Mutex::new(HashMap::new()),
            }
            .build(),
        )
    }

    pub fn locale(&self) -> &str {
        self.0.borrow_locale()
    }

    pub fn db(&self) -> &fontdb::Database {
        self.0.borrow_db()
    }

    pub fn into_locale_and_db(self) -> (String, fontdb::Database) {
        let heads = self.0.into_heads();
        (heads.locale, heads.db)
    }

    // Clippy false positive
    #[allow(clippy::needless_lifetimes)]
    pub fn get_font<'a>(&'a self, id: fontdb::ID) -> Option<Arc<Font<'a>>> {
        self.0.with(|fields| get_font(&fields, id))
    }

    pub fn get_font_matches<'a>(&'a self, attrs: Attrs) -> Arc<FontMatches<'a>> {
        self.0.with(|fields| {
            let mut font_matches_cache = fields
                .font_matches_cache
                .lock()
                .expect("failed to lock font matches cache");
            //TODO: do not create AttrsOwned unless entry does not already exist
            font_matches_cache
                .entry(AttrsOwned::new(attrs))
                .or_insert_with(|| {
                    #[cfg(not(target_arch = "wasm32"))]
                    let now = std::time::Instant::now();

                    let mut fonts = Vec::new();
                    for face in fields.db.faces() {
                        if !attrs.matches(face) {
                            continue;
                        }

                        if let Some(font) = get_font(&fields, face.id) {
                            fonts.push(font);
                        }
                    }

                    let font_matches = Arc::new(FontMatches {
                        locale: fields.locale,
                        default_family: fields.db.family_name(&attrs.family).to_string(),
                        fonts,
                    });

                    #[cfg(not(target_arch = "wasm32"))]
                    {
                        let elapsed = now.elapsed();
                        log::debug!("font matches for {:?} in {:?}", attrs, elapsed);
                    }

                    font_matches
                })
                .clone()
        })
    }
}

fn get_font<'b>(
    fields: &ouroboros_impl_font_system_inner::BorrowedFields<'_, 'b>,
    id: fontdb::ID,
) -> Option<Arc<Font<'b>>> {
    fields
        .font_cache
        .lock()
        .expect("failed to lock font cache")
        .entry(id)
        .or_insert_with(|| {
            let face = fields.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()
}