inotify enhancement for static file server

static_file_handler.hpp

@@ -11,9 +11,13 @@
 #include <filesystem>
 #include <chrono>
 #include <shared_mutex>
+#include <thread>
+#include <atomic>
 #include <zlib.h>
 #include <cstring>
 #include <mutex>
+#include <sys/inotify.h>
+#include <unistd.h>
 
 using std::string_view;
 using std::string;
@@ -28,6 +32,11 @@ private:
 	mutable std::shared_mutex index_mutex_;
 	size_t max_cache_size_ = 50 * 1024 * 1024; // 50MB cache limit
 	
+	int inotify_fd_ = -1;
+	int watch_fd_ = -1;
+	std::thread watch_thread_;
+	std::atomic<bool> stop_watching_{false};
+
 	void build_file_index() {
 		std::unique_lock lock(index_mutex_);
 		file_index_.clear();
@@ -44,6 +53,34 @@ private:
 		}
 	}
 
+	void invalidate_cache() {
+		std::unique_lock lock(index_mutex_);
+		cache_.clear();
+	}
+
+	void watch_files() {
+		char buffer[4096];
+		while (!stop_watching_) {
+			int len = read(inotify_fd_, buffer, sizeof(buffer));
+			if (len <= 0) continue;
+
+			bool needs_rebuild = false;
+			for (int i = 0; i < len;) {
+				struct inotify_event* event = (struct inotify_event*)&buffer[i];
+				if (event->mask & (IN_CREATE | IN_DELETE | IN_MOVED_FROM | IN_MOVED_TO)) {
+					needs_rebuild = true;
+					break;
+				}
+				i += sizeof(struct inotify_event) + event->len;
+			}
+
+			if (needs_rebuild) {
+				build_file_index();
+				invalidate_cache();
+			}
+		}
+	}
+
 	bool file_exists_fast(const string& relative_path) const {
 		std::shared_lock lock(index_mutex_);
 		return file_index_.count(relative_path) > 0;
@@ -106,6 +143,31 @@ public:
 			url_prefix_ += '/';
 		}
 		build_file_index();
+		start_watching();
+	}
+
+	~StaticFileHandler() {
+		stop_watching_ = true;
+		if (watch_thread_.joinable()) {
+			watch_thread_.join();
+		}
+		if (watch_fd_ != -1) close(watch_fd_);
+		if (inotify_fd_ != -1) close(inotify_fd_);
+	}
+
+	void start_watching() {
+		inotify_fd_ = inotify_init1(IN_NONBLOCK);
+		if (inotify_fd_ == -1) return;
+
+		watch_fd_ = inotify_add_watch(inotify_fd_, root_path_.c_str(), 
+			IN_CREATE | IN_DELETE | IN_MOVED_FROM | IN_MOVED_TO);
+		if (watch_fd_ == -1) {
+			close(inotify_fd_);
+			inotify_fd_ = -1;
+			return;
+		}
+
+		watch_thread_ = std::thread(&StaticFileHandler::watch_files, this);
 	}
 
 	void refresh_index() {