refactor(lua): replace std::sync::Mutex with parking_lot::Mutex

Replace std::sync::Mutex with parking_lot::Mutex throughout Lua modules
to simplify lock handling. parking_lot::Mutex never poisons, eliminating
the need for Result handling on lock() calls.

Changes:
- Add parking_lot dependency to Cargo.toml
- Update handler.rs, structures.rs, and userdata.rs to use parking_lot::Mutex
- Remove all .map_err() and .unwrap() calls on mutex locks
- Simplify get_method implementation by removing panic recovery logic
- Update tests to use the new Mutex API

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: DefectingCat

Cargo.lock

@@ -55,6 +55,7 @@ crc32fast = "1.4.2"
 hmac = "0.12.1"
 sha1 = "0.10.6"
 # core
+parking_lot = "0.12"
 tokio = { version = "1.49.0", features = [
     "rt-multi-thread",
     "time",

Cargo.toml

@@ -1,6 +1,6 @@
 use std::collections::hash_map::DefaultHasher;
 use std::hash::{Hash, Hasher};
-use std::sync::{Arc, Mutex};
+use std::sync::Arc;
 use std::time::{SystemTime, UNIX_EPOCH};
 
 use anyhow::{Context, anyhow};
@@ -11,6 +11,7 @@ use axum::{
 };
 use http::Uri;
 use http::header::HeaderMap;
+use parking_lot::Mutex;
 use tokio::fs;
 use tracing::{debug, error, info};
 
@@ -123,10 +124,9 @@ fn build_response(res: CandyResponse, output_buffer: String) -> RouteResult<Resp
 
     // 添加响应头
     let headers = response.headers_mut().unwrap();
-    if let Ok(guard) = res.headers.headers.lock() {
-        for (name, value) in guard.iter() {
-            headers.append(name.clone(), value.clone());
-        }
+    let guard = res.headers.headers.lock();
+    for (name, value) in guard.iter() {
+        headers.append(name.clone(), value.clone());
     }
 
     response
@@ -360,10 +360,7 @@ pub async fn lua(
 
     // 检查请求状态中的输出缓冲区（来自 print 调用）
     let output_buffer = {
-        let state = ctx
-            .req_state
-            .lock()
-            .map_err(|e| RouteError::Any(anyhow!("Failed to acquire request state lock: {}", e)))?;
+        let state = ctx.req_state.lock();
         state.output_buffer.clone()
     };
 

src/http/lua/handler.rs

@@ -1,6 +1,7 @@
-use std::sync::{Arc, Mutex};
+use std::sync::Arc;
 
 use http::{HeaderMap, Uri};
+use parking_lot::Mutex;
 
 /// 为 Lua 脚本提供 HTTP 请求上下文
 #[derive(Clone, Debug)]
@@ -89,10 +90,7 @@ impl CandyHeaders {
 
     /// 获取所有 headers 作为 Lua table
     pub fn get_headers_table(&self, lua: &mlua::Lua) -> mlua::Result<mlua::Table> {
-        let headers = self
-            .headers
-            .lock()
-            .map_err(|e| mlua::Error::external(anyhow::anyhow!("Failed to lock headers: {}", e)))?;
+        let headers = self.headers.lock();
 
         let table = lua.create_table()?;
         for (name, value) in headers.iter() {
@@ -231,7 +229,8 @@ mod tests {
         fn test_new() {
             let headers = HeaderMap::new();
             let candy_headers = CandyHeaders::new(headers);
-            assert!(candy_headers.headers.lock().is_ok());
+            // parking_lot Mutex::lock() 总是成功，返回 MutexGuard
+            let _guard = candy_headers.headers.lock();
         }
 
         #[test]
@@ -295,7 +294,7 @@ mod tests {
             );
 
             let candy_headers = CandyHeaders::new(headers);
-            let guard = candy_headers.headers.lock().unwrap();
+            let guard = candy_headers.headers.lock();
 
             assert_eq!(
                 guard.get(http::header::CONTENT_TYPE).unwrap(),
@@ -337,7 +336,7 @@ mod tests {
                 body: Arc::new(Mutex::new(Some(body_data.to_vec()))),
             };
 
-            let guard = request.body.lock().unwrap();
+            let guard = request.body.lock();
             assert_eq!(guard.as_ref().unwrap(), body_data);
         }
 
@@ -351,7 +350,7 @@ mod tests {
                 body: Arc::new(Mutex::new(None)),
             };
 
-            let guard = request.body.lock().unwrap();
+            let guard = request.body.lock();
             assert!(guard.is_none());
         }
     }
@@ -484,7 +483,6 @@ mod tests {
             let headers = Arc::new(Mutex::new(HeaderMap::new()));
             headers
                 .lock()
-                .unwrap()
                 .insert(http::header::HOST, HeaderValue::from_static("localhost"));
 
             let state = CandyReqState {
@@ -503,7 +501,7 @@ mod tests {
             assert_eq!(state.uri_path, "/original");
 
             // Verify header access
-            let guard = state.headers.lock().unwrap();
+            let guard = state.headers.lock();
             assert_eq!(guard.get(http::header::HOST).unwrap(), "localhost");
         }