wire up configuration, review feedback

Signed-off-by: Brian L. Troutwine <brian.troutwine@datadoghq.com>

lading/src/generator/file_gen.rs

@@ -29,6 +29,9 @@ pub enum Error {
     /// Wrapper around [`traditional::Error`].
     #[error(transparent)]
     Traditional(#[from] traditional::Error),
+    /// Wrapper around [`logrotate::Error`].
+    #[error(transparent)]
+    Logrotate(#[from] logrotate::Error),
 }
 
 /// Configuration of [`FileGen`]
@@ -37,6 +40,8 @@ pub enum Error {
 pub enum Config {
     /// See [`traditional::Config`].
     Traditional(traditional::Config),
+    /// See [`logrotate::Config`].
+    Logrotate(logrotate::Config),
 }
 
 #[derive(Debug)]
@@ -47,6 +52,8 @@ pub enum Config {
 pub enum FileGen {
     /// See [`traditional::Server`] for details.
     Traditional(traditional::Server),
+    /// See [`logrotate::Server`] for details.
+    Logrotate(logrotate::Server),
 }
 
 impl FileGen {
@@ -66,6 +73,7 @@ impl FileGen {
             Config::Traditional(c) => {
                 Self::Traditional(traditional::Server::new(general, c, shutdown)?)
             }
+            Config::Logrotate(c) => Self::Logrotate(logrotate::Server::new(general, c, shutdown)?),
         };
         Ok(srv)
     }
@@ -85,6 +93,7 @@ impl FileGen {
     pub async fn spin(self) -> Result<(), Error> {
         match self {
             Self::Traditional(inner) => inner.spin().await?,
+            Self::Logrotate(inner) => inner.spin().await?,
         };
 
         Ok(())

lading/src/generator/file_gen/logrotate.rs

@@ -237,7 +237,8 @@ impl Child {
         throttle: Throttle,
         shutdown: Shutdown,
     ) -> Self {
-        let mut names = Vec::with_capacity(total_rotations as usize);
+        let mut names = Vec::with_capacity((total_rotations + 1).into());
+        names.push(PathBuf::from(basename));
         for i in 0..total_rotations {
             let name = format!(
                 "{orig}.{i}",
@@ -265,9 +266,10 @@ impl Child {
         let maximum_bytes_per_log: u64 = u64::from(self.maximum_bytes_per_log.get());
 
         let total_names = self.names.len();
-        let last_name = &self.names[total_names];
+        // SAFETY: By construction there is guaranteed to be at least one name.
+        let last_name = &self.names.last().unwrap();
 
-        // SAFETY: By construction the name is guranteed to have a parent.
+        // SAFETY: By construction the name is guaranteed to have a parent.
         fs::create_dir_all(&self.names[0].parent().unwrap()).await?;
         let mut fp = BufWriter::with_capacity(
             bytes_per_second,
@@ -288,6 +290,8 @@ impl Child {
         let bytes_written = register_counter!("bytes_written");
 
         loop {
+            // SAFETY: By construction the block cache will never be empty
+            // except in the event of a catastrophic failure.
             let blk = rcv.peek().await.unwrap();
             let total_bytes = blk.total_bytes;