refactor(bare): enhance security and performance optimizations

- Remove unnecessary sorting in advertise_refs for deterministic output
- Add path traversal detection and validation in bare_dir construction
- Implement symlink resolution checks to prevent security vulnerabilities
- Refactor cache system with CRC validation and improved metrics
- Integrate repo-specific cache invalidation using indexed keys
- Add comprehensive unit tests for commit operations and diff functionality
- Move configuration constants to centralized config module
- Optimize string operations in disk cache random value generation
- Enhance license detection algorithm with cleaner matching logic
- Streamline argument processing in various git operations
- Update dependencies including crc32fast and flate2 for performance
- Add signal handling capability to tokio runtime configuration

repository/lang_stats.rs

@@ -7,7 +7,6 @@ use crate::bare::GitBare;
 use crate::error::{GitError, GitResult};
 use crate::pb::{GetLanguageStatsRequest, GetLanguageStatsResponse, LanguageStat, object_selector};
 
-// Include the generated linguist rules
 include!(concat!(env!("OUT_DIR"), "/linguist_generated.rs"));
 
 /// Default max file size for line counting (512 KB).
@@ -17,7 +16,6 @@ const MAX_TREE_WALK_DEPTH: usize = 256;
 /// Look up a language by file extension (case-insensitive, includes leading dot).
 fn lookup_by_extension(ext: &str) -> Option<(&'static str, &'static str)> {
     let ext_lower = ext.to_lowercase();
-    // Binary search on the sorted EXTENSION_MAP
     EXTENSION_MAP
         .binary_search_by(|&(e, _, _)| e.cmp(ext_lower.as_str()))
         .ok()
@@ -54,13 +52,11 @@ fn detect_language(path: &str, is_binary: bool) -> Option<(&'static str, &'stati
         .and_then(|n| n.to_str())
         .unwrap_or("");
 
-    // Try filename match first (e.g., Makefile, Dockerfile)
     if let Some(result) = lookup_by_filename(file_name) {
         tracing::debug!(path = %path, lang = result.0, "matched by filename");
         return Some(result);
     }
 
-    // Try extension match
     if let Some(ext) = Path::new(path).extension().and_then(|e| e.to_str()) {
         let ext_with_dot = format!(".{ext}");
         if let Some(result) = lookup_by_extension(&ext_with_dot) {
@@ -72,13 +68,10 @@ fn detect_language(path: &str, is_binary: bool) -> Option<(&'static str, &'stati
         tracing::debug!(path = %path, "no extension found");
     }
 
-    // For binary files with no recognized extension, classify by media type
     if is_binary {
-        // Try extension-based binary classification
         if let Some(ext) = Path::new(path).extension().and_then(|e| e.to_str()) {
             let ext_lower = format!(".{ext}").to_lowercase();
             let media_type = classify_binary_extension(&ext_lower);
-            // Return as a synthetic language name
             return Some((media_type, "data"));
         }
         return Some(("Binary", "data"));
@@ -146,7 +139,6 @@ impl GitBare {
             .try_into_tree()
             .map_err(|e| GitError::Gix(e.to_string()))?;
 
-        // If path is specified, descend into subdirectory
         if !request.path.is_empty() {
             crate::sanitize::validate_file_path(&request.path)?;
             let entry = tree
@@ -173,7 +165,6 @@ impl GitBare {
         };
         self.walk_tree(&repo, &tree, &prefix, 0, &mut ctx)?;
 
-        // Resolve groups: merge child language stats into parent group
         tracing::info!(
             total_files,
             total_bytes,
@@ -193,13 +184,11 @@ impl GitBare {
             entry.file_count = entry.file_count.saturating_add(s.file_count);
             entry.bytes = entry.bytes.saturating_add(s.bytes);
             entry.lines = entry.lines.saturating_add(s.lines);
-            // Keep the lang_type from the parent (or first encountered)
             if entry.lang_type.is_empty() {
                 entry.lang_type = s.lang_type;
             }
         }
 
-        // Build response sorted by bytes descending
         let mut languages: Vec<LanguageStat> = resolved
             .into_iter()
             .map(|(language, s)| {
@@ -272,15 +261,12 @@ impl GitBare {
                     let data = &blob.data;
                     let size = data.len() as u64;
 
-                    // Skip empty files
                     if size == 0 {
                         continue;
                     }
 
-                    // Check if binary (contains null byte)
                     let is_binary = data.contains(&0);
 
-                    // Detect language
                     let Some((lang_name, lang_type)) = detect_language(&path, is_binary) else {
                         tracing::debug!(path = %path, is_binary, "no language detected");
                         continue;
@@ -288,7 +274,6 @@ impl GitBare {
 
                     let lang_key = lang_name.to_string();
 
-                    // Count code lines only for non-binary files within size limit
                     let lines = if !is_binary && size <= u64::from(ctx.max_file_size) {
                         count_code_lines(data)
                     } else {