修复linux的编译

module/Local_Server/server/tiles.cpp

@@ -1,9 +1,15 @@
 #include "Global.h"
 #include "Performance_Monitor.h"
 #include <algorithm>
+#include <asio/use_awaitable.hpp>
+#if defined(ASIO_HAS_FILE)
 #include <asio/random_access_file.hpp>
 #include <asio/read_at.hpp>
-#include <asio/use_awaitable.hpp>
+#else
+#include <asio/co_spawn.hpp>
+#include <asio/thread_pool.hpp>
+#include <fstream>
+#endif
 #include <cctype>
 #include <cstdint>
 #include <ctime>
@@ -222,12 +228,16 @@ public:
         }
         std::string content;
         if (cache_request.include_body) {
+#if defined(ASIO_HAS_FILE)
             auto executor = co_await asio::this_coro::executor;
             asio::random_access_file file(executor, path->generic_string(), asio::file_base::read_only);
             content.resize(static_cast<std::size_t>(cache_info->size));
             if (!content.empty()) {
                 co_await asio::async_read_at(file, 0, asio::buffer(content.data(), content.size()), asio::use_awaitable);
             }
+#else
+            content = co_await read_file_fallback(*path, static_cast<std::size_t>(cache_info->size));
+#endif
         }
         co_return Tile_Load_Result{Tile_Load_Status::Ready, std::move(generic_path), std::move(content), std::move(content_type), *cache_info};
     }
@@ -236,6 +246,28 @@ public:
     }
 private:
     Tile_Path_Resolver resolver_;
+#if !defined(ASIO_HAS_FILE)
+    static asio::thread_pool& tile_file_pool() {
+        static asio::thread_pool pool(4);
+        return pool;
+    }
+    static asio::awaitable<std::string> read_file_fallback(std::filesystem::path path, std::size_t size) {
+        co_return co_await asio::co_spawn(tile_file_pool(), [path = std::move(path), size]() -> asio::awaitable<std::string> {
+            std::ifstream file(path, std::ios::binary);
+            if (!file) {
+                throw std::runtime_error("failed to open tile file: " + path.generic_string());
+            }
+            std::string content(size, '\0');
+            if (!content.empty()) {
+                file.read(content.data(), static_cast<std::streamsize>(content.size()));
+                if (file.gcount() != static_cast<std::streamsize>(content.size())) {
+                    throw std::runtime_error("failed to read complete tile file: " + path.generic_string());
+                }
+            }
+            co_return content;
+        }, asio::use_awaitable);
+    }
+#endif
 };
 drogon::HttpResponsePtr make_tile_not_found_response(std::string_view request_path, bool include_body) {
     auto response = drogon::HttpResponse::newHttpResponse();