Improved memory and disk usage, best practices. Review done by GPT 5.2, code written by Claude Opus 4.5

src/files.rs

@@ -1,10 +1,41 @@
-use anyhow::{anyhow, Result};
+use anyhow::{Result, anyhow};
 use chrono::NaiveDate;
 use flate2::read::GzDecoder;
 use std::fs::File;
-use std::io::{BufRead, BufReader};
+use std::io::{BufRead, BufReader, Read};
 use std::path::PathBuf;
 
+/// Enum-based reader to avoid Box<dyn BufRead> heap allocation and dynamic dispatch
+pub enum LogReader {
+    Plain(BufReader<File>),
+    Gzip(BufReader<GzDecoder<File>>),
+}
+
+impl Read for LogReader {
+    fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
+        match self {
+            LogReader::Plain(r) => r.read(buf),
+            LogReader::Gzip(r) => r.read(buf),
+        }
+    }
+}
+
+impl BufRead for LogReader {
+    fn fill_buf(&mut self) -> std::io::Result<&[u8]> {
+        match self {
+            LogReader::Plain(r) => r.fill_buf(),
+            LogReader::Gzip(r) => r.fill_buf(),
+        }
+    }
+
+    fn consume(&mut self, amt: usize) {
+        match self {
+            LogReader::Plain(r) => r.consume(amt),
+            LogReader::Gzip(r) => r.consume(amt),
+        }
+    }
+}
+
 /// Discovers log files for a given date range
 pub struct LogFileDiscovery {
     base_dir: PathBuf,
@@ -25,9 +56,7 @@ impl LogFileDiscovery {
             if let Some(log_file) = self.find_log_for_date(current)? {
                 files.push(log_file);
             }
-            current = current
-                .succ_opt()
-                .ok_or_else(|| anyhow!("Date overflow"))?;
+            current = current.succ_opt().ok_or_else(|| anyhow!("Date overflow"))?;
         }
 
         Ok(files)
@@ -72,26 +101,26 @@ pub struct LogFile {
 
 impl LogFile {
     /// Returns a buffered reader for this log file, handling compression transparently
-    pub fn reader(&self) -> Result<Box<dyn BufRead>> {
+    pub fn reader(&self) -> Result<LogReader> {
         let file = File::open(&self.path)?;
 
         if self.compressed {
             let decoder = GzDecoder::new(file);
-            Ok(Box::new(BufReader::new(decoder)))
+            Ok(LogReader::Gzip(BufReader::new(decoder)))
         } else {
-            Ok(Box::new(BufReader::new(file)))
+            Ok(LogReader::Plain(BufReader::new(file)))
         }
     }
 }
 
 /// For reading a single file directly (e.g., for testing)
-pub fn read_log_file(path: &str) -> Result<Box<dyn BufRead>> {
+pub fn read_log_file(path: &str) -> Result<LogReader> {
     let file = File::open(path)?;
 
     if path.ends_with(".gz") {
         let decoder = GzDecoder::new(file);
-        Ok(Box::new(BufReader::new(decoder)))
+        Ok(LogReader::Gzip(BufReader::new(decoder)))
     } else {
-        Ok(Box::new(BufReader::new(file)))
+        Ok(LogReader::Plain(BufReader::new(file)))
     }
 }