Refactor ETag handling: extract check_if_not_modified and check_if_range methods for improved readability and maintainability

httplib.h

@@ -1258,6 +1258,10 @@ private:
 
   bool routing(Request &req, Response &res, Stream &strm);
   bool handle_file_request(Request &req, Response &res);
+  bool check_if_not_modified(const Request &req, Response &res,
+                             const std::string &etag, time_t mtime) const;
+  bool check_if_range(Request &req, const std::string &etag,
+                      time_t mtime) const;
   bool dispatch_request(Request &req, Response &res,
                         const Handlers &handlers) const;
   bool dispatch_request_for_content_reader(
@@ -8357,7 +8361,6 @@ inline bool Server::handle_file_request(Request &req, Response &res) {
             res.set_header(kv.first, kv.second);
           }
 
-          // Compute and set weak ETag based on mtime+size.
           auto etag = detail::compute_etag(stat);
           if (!etag.empty()) { res.set_header("ETag", etag); }
 
@@ -8368,6 +8371,42 @@ inline bool Server::handle_file_request(Request &req, Response &res) {
             res.set_header("Last-Modified", last_modified);
           }
 
+          if (check_if_not_modified(req, res, etag, mtime)) { return true; }
+
+          check_if_range(req, etag, mtime);
+
+          auto mm = std::make_shared<detail::mmap>(path.c_str());
+          if (!mm->is_open()) {
+            output_error_log(Error::OpenFile, &req);
+            return false;
+          }
+
+          res.set_content_provider(
+              mm->size(),
+              detail::find_content_type(path, file_extension_and_mimetype_map_,
+                                        default_file_mimetype_),
+              [mm](size_t offset, size_t length, DataSink &sink) -> bool {
+                sink.write(mm->data() + offset, length);
+                return true;
+              });
+
+          if (req.method != "HEAD" && file_request_handler_) {
+            file_request_handler_(req, res);
+          }
+
+          return true;
+        } else {
+          output_error_log(Error::OpenFile, &req);
+        }
+      }
+    }
+  }
+  return false;
+}
+
+inline bool Server::check_if_not_modified(const Request &req, Response &res,
+                                          const std::string &etag,
+                                          time_t mtime) const {
   // Handle conditional GET:
   // 1. If-None-Match takes precedence (RFC 9110 Section 13.1.2)
   // 2. If-Modified-Since is checked only when If-None-Match is absent
@@ -8404,7 +8443,11 @@ inline bool Server::handle_file_request(Request &req, Response &res) {
       return true;
     }
   }
+  return false;
+}
 
+inline bool Server::check_if_range(Request &req, const std::string &etag,
+                                   time_t mtime) const {
   // Handle If-Range for partial content requests (RFC 9110
   // Section 13.1.5). If-Range is only evaluated when Range header is
   // present. If the validator matches, serve partial content; otherwise
@@ -8423,43 +8466,17 @@ inline bool Server::handle_file_request(Request &req, Response &res) {
     } else {
       // HTTP-date comparison
       auto if_range_time = detail::parse_http_date(val);
-              valid = (if_range_time != static_cast<time_t>(-1) &&
+      valid =
-                       mtime <= if_range_time);
+          (if_range_time != static_cast<time_t>(-1) && mtime <= if_range_time);
     }
 
     if (!valid) {
       // Validator doesn't match: ignore Range and serve full content
       req.ranges.clear();
-            }
-          }
-
-          auto mm = std::make_shared<detail::mmap>(path.c_str());
-          if (!mm->is_open()) {
-            output_error_log(Error::OpenFile, &req);
       return false;
     }
-
+  }
-          res.set_content_provider(
-              mm->size(),
-              detail::find_content_type(path, file_extension_and_mimetype_map_,
-                                        default_file_mimetype_),
-              [mm](size_t offset, size_t length, DataSink &sink) -> bool {
-                sink.write(mm->data() + offset, length);
   return true;
-              });
-
-          if (req.method != "HEAD" && file_request_handler_) {
-            file_request_handler_(req, res);
-          }
-
-          return true;
-        } else {
-          output_error_log(Error::OpenFile, &req);
-        }
-      }
-    }
-  }
-  return false;
 }
 
 inline socket_t