feat(server): add tracing spans and caching to archive and blame services

- Add tracing spans with repo labels for archive and blame operations
- Implement caching for archive list entries when using OID selectors
- Implement caching for blame operations when using OID selectors
- Add detailed

server/mod.rs

@@ -1,6 +1,7 @@
 mod archive;
 mod blame;
 mod branch;
+mod cache;
 mod commit;
 mod diff;
 mod merge;
@@ -23,11 +24,23 @@ use crate::pb::{
 
 #[derive(Clone)]
 pub struct GitksService {
-    /// 所有仓库的根路径前缀
-    pub(crate) repo_prefix: PathBuf,
+    /// Root prefix path for all repositories
+    pub repo_prefix: PathBuf,
 }
 
 impl GitksService {
+    fn repo_label(&self, header: Option<&crate::pb::RepositoryHeader>) -> String {
+        header
+            .and_then(|h| {
+                if h.relative_path.is_empty() {
+                    None
+                } else {
+                    Some(h.relative_path.clone())
+                }
+            })
+            .unwrap_or_else(|| "unknown".into())
+    }
+
     pub(crate) fn resolve(
         &self,
         header: Option<&crate::pb::RepositoryHeader>,
@@ -35,7 +48,12 @@ impl GitksService {
         let header =
             header.ok_or_else(|| tonic::Status::invalid_argument("repository is required"))?;
         let header = self.prefixed_header(header);
-        GitBare::from_repository_header(&header).map_err(into_status)
+        let gb = GitBare::from_repository_header(&header).map_err(into_status)?;
+        tracing::debug!(
+            repo = %gb.bare_dir.display(),
+            "resolved repository"
+        );
+        Ok(gb)
     }
 
     pub(crate) fn resolve_for_init(
@@ -49,7 +67,7 @@ impl GitksService {
             return Err(tonic::Status::invalid_argument("relative_path is required"));
         }
         let candidate = self.repo_prefix.join(relative_path);
-        // 路径穿越检查
+        // Path traversal check
         let canonical = candidate
             .canonicalize()
             .unwrap_or_else(|_| candidate.clone());
@@ -65,11 +83,8 @@ impl GitksService {
         Ok(canonical)
     }
 
-    /// 将客户端传入的 header 注入 repo_prefix 作为 storage_path
-    fn prefixed_header(
-        &self,
-        header: &crate::pb::RepositoryHeader,
-    ) -> crate::pb::RepositoryHeader {
+    /// Inject repo_prefix as storage_path into the client-provided header
+    fn prefixed_header(&self, header: &crate::pb::RepositoryHeader) -> crate::pb::RepositoryHeader {
         crate::pb::RepositoryHeader {
             storage_path: self.repo_prefix.to_string_lossy().into_owned(),
             relative_path: header.relative_path.clone(),
@@ -115,20 +130,49 @@ pub(crate) fn git_cmd(gb: &GitBare, args: &[&str]) -> Result<std::process::Outpu
         gb.bare_dir.to_string_lossy().into_owned(),
     ];
     full_args.extend(args.iter().map(|s| s.to_string()));
-    std::process::Command::new("git")
+    tracing::debug!(
+        repo = %gb.bare_dir.display(),
+        args = %full_args.iter().skip(2).cloned().collect::<Vec<_>>().join(" "),
+        "spawning git subprocess"
+    );
+    let result = std::process::Command::new("git")
         .args(&full_args)
         .output()
-        .map_err(|e| tonic::Status::internal(e.to_string()))
+        .map_err(|e| {
+            tracing::error!(
+                repo = %gb.bare_dir.display(),
+                error = %e,
+                "failed to spawn git subprocess"
+            );
+            tonic::Status::internal(e.to_string())
+        })?;
+    if !result.status.success() {
+        let stderr = String::from_utf8_lossy(&result.stderr);
+        tracing::warn!(
+            repo = %gb.bare_dir.display(),
+            status = ?result.status.code(),
+            stderr = %stderr.trim(),
+            "git subprocess exited with non-zero status"
+        );
+    }
+    Ok(result)
 }
 
 pub async fn serve(
     addr: std::net::SocketAddr,
     repo_prefix: PathBuf,
 ) -> Result<(), tonic::transport::Error> {
+    let span = tracing::info_span!("gitks.server", %addr);
+    let _enter = span.enter();
     let svc = GitksService { repo_prefix };
-    tonic::transport::Server::builder()
-        .add_service(repository_service_server::RepositoryServiceServer::new(svc.clone()))
-        .add_service(archive_service_server::ArchiveServiceServer::new(svc.clone()))
+    tracing::info!("registering gRPC services");
+    let server = tonic::transport::Server::builder()
+        .add_service(repository_service_server::RepositoryServiceServer::new(
+            svc.clone(),
+        ))
+        .add_service(archive_service_server::ArchiveServiceServer::new(
+            svc.clone(),
+        ))
         .add_service(blame_service_server::BlameServiceServer::new(svc.clone()))
         .add_service(branch_service_server::BranchServiceServer::new(svc.clone()))
         .add_service(commit_service_server::CommitServiceServer::new(svc.clone()))
@@ -136,7 +180,7 @@ pub async fn serve(
         .add_service(merge_service_server::MergeServiceServer::new(svc.clone()))
         .add_service(pack_service_server::PackServiceServer::new(svc.clone()))
         .add_service(tag_service_server::TagServiceServer::new(svc.clone()))
-        .add_service(tree_service_server::TreeServiceServer::new(svc))
-        .serve(addr)
-        .await
+        .add_service(tree_service_server::TreeServiceServer::new(svc));
+    tracing::info!("server ready, starting to accept connections");
+    server.serve(addr).await
 }