Initial commit

src/config.rs

@@ -0,0 +1,91 @@
+use serde::de::Visitor;
+use serde::{Deserialize, Deserializer};
+use std::fmt;
+use std::path::PathBuf;
+use std::time::Duration;
+
+#[derive(Deserialize)]
+pub struct Config {
+    /// The folder from which to reap
+    pub path: PathBuf,
+
+    /// Whether to treat the files as btrfs subvolumes
+    #[serde(default)]
+    pub btrfs: bool,
+
+    pub periods: Vec<ConfPeriod>,
+}
+
+#[derive(Deserialize)]
+pub struct ConfPeriod {
+    /// The total duration of this period
+    #[serde(deserialize_with = "parse_duration")]
+    pub period_length: Duration,
+
+    /// The size of chunks in this period. Each chunk should hold 1 file.
+    #[serde(deserialize_with = "parse_duration")]
+    pub chunk_size: Duration,
+}
+
+fn parse_duration<'de, D>(d: D) -> Result<Duration, D::Error>
+where
+    D: Deserializer<'de>,
+{
+    let s = d.deserialize_string(StringVisitor)?;
+
+    let mut duration = Duration::ZERO;
+
+    for part in s.split_whitespace() {
+        if part.len() < 2 {
+            continue;
+        }
+
+        let suffix = part.chars().rev().next().unwrap();
+        let value = &part[..part.len() - suffix.len_utf8()];
+
+        let value: u32 = value.parse().expect("failed to parse duration value");
+
+        let second: Duration = Duration::from_secs(1);
+        let minute: Duration = second * 60;
+        let hour: Duration = minute * 60;
+        let day: Duration = hour * 24;
+        let week: Duration = day * 7;
+        let year: Duration = day * 365;
+
+        let unit = match suffix.to_ascii_lowercase() {
+            's' => second,
+            'm' => minute,
+            'h' => hour,
+            'd' => day,
+            'w' => week,
+            'y' => year,
+            _ => panic!("unknown unit of duration"),
+        };
+
+        duration += unit * value;
+    }
+
+    if duration == Duration::ZERO {
+        panic!("Invalid duration: Zero");
+    }
+
+    Ok(duration)
+}
+
+struct StringVisitor;
+
+impl<'de> Visitor<'de> for StringVisitor {
+    type Value = String;
+
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("a string")
+    }
+
+    fn visit_string<E>(self, value: String) -> Result<Self::Value, E> {
+        Ok(value)
+    }
+
+    fn visit_str<E>(self, value: &str) -> Result<Self::Value, E> {
+        Ok(value.to_string())
+    }
+}