add rar support

src/logfile/archive/rar.rs

@@ -0,0 +1,52 @@
+use crate::error::ReadError;
+use crate::logfile::archive::{Archive, ArchiveEntry};
+use std::borrow::Cow;
+
+pub struct RarArchive {
+    path: String,
+}
+
+impl RarArchive {
+    pub fn new(path: &str) -> Result<Self, ReadError> {
+        Ok(RarArchive { path: path.into() })
+    }
+}
+
+pub struct RarEntry {
+    archive: String,
+    name: String,
+}
+
+impl ArchiveEntry for RarEntry {
+    fn name(&self) -> Cow<str> {
+        self.name.as_str().into()
+    }
+
+    fn extract(self) -> Result<Vec<u8>, ReadError> {
+        let mut archive = unrar::Archive::new(&self.archive).open_for_processing()?;
+        while let Some(header) = archive.read_header()? {
+            if header.entry().filename.to_string_lossy() == self.name {
+                return Ok(header.read()?.0);
+            }
+            archive = header.skip()?;
+        }
+        Err(ReadError::NoFiles)
+    }
+}
+
+impl Archive for RarArchive {
+    type Entry<'a> = RarEntry;
+
+    fn entries(&mut self) -> impl Iterator<Item = Self::Entry<'_>> {
+        unrar::Archive::new(&self.path)
+            .open_for_listing()
+            .into_iter()
+            .flatten()
+            .into_iter()
+            .flatten()
+            .map(|header| RarEntry {
+                archive: self.path.clone(),
+                name: header.filename.to_string_lossy().into(),
+            })
+    }
+}