moss/boulder: Add support for font providers

Reads FAMILY_NAME from OpenType fonts in order to provide a font
provider.

e.g. `moss it 'font(Noto Sans Tamil Condensed Thin)'`

Cargo.toml

@@ -53,6 +53,7 @@ tokio-util = { version = "0.7.11", features = ["io"] }
 url = { version = "2.5.2", features = ["serde"] }
 xxhash-rust = { version = "0.8.11", features = ["xxh3"] }
 zstd = { version = "0.13.2", features = ["zstdmt"] }
+read-fonts = "0.20.0"
 
 [profile.release]
 lto = "thin"

boulder/Cargo.toml

@@ -43,3 +43,4 @@ strum.workspace = true
 thiserror.workspace = true
 tokio.workspace = true
 url.workspace = true
+read-fonts.workspace = true

boulder/src/package/analysis.rs

@@ -38,6 +38,7 @@ impl<'a> Chain<'a> {
                 Box::new(handler::elf),
                 Box::new(handler::pkg_config),
                 Box::new(handler::cmake),
+                Box::new(handler::font),
                 // Catch-all if not excluded
                 Box::new(handler::include_any),
             ],

boulder/src/package/analysis/handler.rs

@@ -1,6 +1,7 @@
 use std::{path::PathBuf, process::Command};
 
 use moss::{dependency, Dependency, Provider};
+use read_fonts::{types::NameId, FontRef, TableProvider};
 
 use crate::package::collect::PathInfo;
 
@@ -136,3 +137,30 @@ pub fn cmake(bucket: &mut BucketMut, info: &mut PathInfo) -> Result<Response, Bo
 
     Ok(Decision::NextHandler.into())
 }
+
+pub fn font(bucket: &mut BucketMut, info: &mut PathInfo) -> Result<Response, BoxError> {
+    if !info.target_path.starts_with("/usr/share/font")
+        && !(info.file_name().ends_with(".ttf") || info.file_name().ends_with(".otf"))
+    {
+        return Ok(Decision::NextHandler.into());
+    }
+
+    let bytes = std::fs::read(&info.path)?;
+    let font = FontRef::new(&bytes)?;
+    let font_name_table = font.name()?;
+    if let Some(record) = font_name_table
+        .name_record()
+        .into_iter()
+        .find(|record| record.name_id() == NameId::FAMILY_NAME)
+    {
+        let data = record.string(font_name_table.string_data())?;
+        let family_name = data.chars().collect::<String>();
+
+        bucket.providers.insert(Provider {
+            kind: dependency::Kind::Font,
+            name: family_name,
+        });
+    }
+
+    Ok(Decision::NextHandler.into())
+}

crates/stone/src/payload/meta.rs

@@ -50,6 +50,9 @@ pub enum Dependency {
 
     /// An emul32-compatible pkgconfig .pc dependency (lib32/*.pc)
     PkgConfig32,
+
+    /// OpenType Font FAMILY_NAME
+    Font,
 }
 
 #[repr(u8)]
@@ -146,6 +149,7 @@ fn decode_dependency(i: u8) -> Result<Dependency, DecodeError> {
         6 => Dependency::Binary,
         7 => Dependency::SystemBinary,
         8 => Dependency::PkgConfig32,
+        9 => Dependency::Font,
         _ => return Err(DecodeError::UnknownDependency(i)),
     };
     Ok(result)

moss/src/dependency.rs

@@ -59,6 +59,9 @@ pub enum Kind {
 
     /// Exported 32-bit pkgconfig provider
     PkgConfig32,
+
+    /// OpenType Font FAMILY_NAME
+    Font,
 }
 
 /// Convert payload dependency types to our internal representation
@@ -74,6 +77,7 @@ impl From<payload::meta::Dependency> for Kind {
             payload::meta::Dependency::Binary => Kind::Binary,
             payload::meta::Dependency::SystemBinary => Kind::SystemBinary,
             payload::meta::Dependency::PkgConfig32 => Kind::PkgConfig32,
+            payload::meta::Dependency::Font => Kind::Font,
         }
     }
 }
@@ -91,6 +95,7 @@ impl From<Kind> for payload::meta::Dependency {
             Kind::Binary => Self::Binary,
             Kind::SystemBinary => Self::SystemBinary,
             Kind::PkgConfig32 => Self::PkgConfig32,
+            Kind::Font => Self::Font,
         }
     }
 }