intial commit

src/conf.rs

@@ -0,0 +1,64 @@
+use std::{
+    fmt::Debug,
+    fs::File,
+    io::{self, Read, Seek},
+};
+
+use libc::gid_t;
+use serde::{Deserialize, Serialize};
+
+#[derive(Serialize, Deserialize)]
+#[serde(untagged)]
+pub enum Either<T, U> {
+    Left(T),
+    Right(U),
+}
+
+impl<T: Debug, U: Debug> Debug for Either<T, U> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Left(l) => l.fmt(f),
+            Self::Right(r) => r.fmt(f),
+        }
+    }
+}
+
+pub type Group = Either<String, gid_t>;
+
+#[derive(Debug, Default, Serialize, Deserialize)]
+#[serde(default)]
+pub struct Unix {
+    groups: Vec<Group>,
+}
+
+#[derive(Debug, Default, Serialize, Deserialize)]
+#[serde(default)]
+pub struct Config {
+    unix: Unix,
+}
+
+#[derive(thiserror::Error, Debug)]
+pub enum ConfigParseError {
+    #[error(transparent)]
+    Io(#[from] io::Error),
+
+    #[error(transparent)]
+    Parse(#[from] toml::de::Error),
+}
+
+impl Config {
+    /// # Errors
+    ///
+    /// For IO errors reading the file or parsing errors.
+    pub fn from_toml_file(f: &mut File) -> Result<Self, ConfigParseError> {
+        let mut buf = Vec::new();
+        if let Ok(len) = f.stream_len() {
+            // There's no way a config file passes machine's memory limitations
+            #[allow(clippy::cast_possible_truncation)]
+            buf.reserve_exact(len as usize);
+        }
+        f.read_to_end(&mut buf)?;
+
+        Ok(toml::from_slice(&buf)?)
+    }
+}