tidy the file tree

src/method_executor.rb

@@ -0,0 +1,134 @@
+# <<*>> -^v- SNOWARE APPLICATION
+# usage: Automatic operator implementation.
+# author: S.A.
+# time: 2026-06-07
+# Copyright (c) [2026] [S.A. SNOWARE-SCU]
+# [MineSentinel] is licensed under Mulan PubL v2.
+# You can use this software according to the terms and conditions of the Mulan PubL v2.
+# You may obtain a copy of Mulan PubL v2 at:
+#          http://license.coscl.org.cn/MulanPubL-2.0
+# THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
+# EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
+# MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
+# See the Mulan PubL v2 for more details.
+
+# frozen_string_literal: true
+
+PERSISTENCE_PERIOD = 30 # Wait for systemctl to take the order.
+
+require 'logger'
+require_relative 'server_status_detector'
+
+# rubocop:disable Style/ClassVars
+class MethodExecutor
+  RST_COUNTS_LIMIT = 10
+  @@rst_counter = 0
+  # Initialize the standard log system.
+  @@logger = Logger.new($stdout) # This script will be launched as a systemd server.
+  $stdout.sync = true
+  $stderr.sync = true
+  # Fetch the environmental variable and convert it into log level.
+  @@logger.level = case ENV.fetch('LOG_LEVEL', nil) # @为单个实例（半生不熟的概念，貌似是在不同的空间独立创建），@@为共享同一个
+                   when nil, 'debug' # Default config.
+                     Logger::Severity::DEBUG
+                   when 'info'
+                     Logger::Severity::INFO
+                   when 'warn'
+                     Logger::Severity::WARN
+                   when 'error'
+                     Logger::Severity::ERROR
+                   else
+                     raise ArgumentError
+                   end
+  @@logger.progname = 'MineSentinel'
+
+  # rubocop:disable Metrics/MethodLength
+
+  # @param level [String] "info" | "warn" | "error" | "debug"
+  # @param module_name [String]
+  # @param message [String]
+  # @return [void]
+  def self.record(level, module_name, message)
+    case level
+    when 'info'
+      @@logger.info("#{module_name}: #{message}")
+    when 'warn'
+      @@logger.warn("#{module_name}: #{message}")
+    when 'error'
+      @@logger.error("#{module_name}: #{message}")
+    when 'debug'
+      @@logger.debug("#{module_name}: #{message}")
+    else
+      raise ArgumentError
+    end
+  end
+
+  # rubocop:enable Metrics/MethodLength
+  # rubocop:disable Metrics/MethodLength, Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
+
+  # @return [void]
+  def self.reset_minecraft_server
+    record('info', 'reset', "Attempt ##{@@rst_counter + 1} to reset Minecraft server.")
+
+    if @@rst_counter >= RST_COUNTS_LIMIT
+      record('error', 'reset',
+             "Tried #{RST_COUNTS_LIMIT} times and failed, now I'll idle until server is manually restarted.")
+      loop do
+        sleep 10
+        SystemdNotifier.notify('WATCHDOG=1') if defined?(SystemdNotifier)
+        next unless ServerStatusDetector::MinecraftServer.self_diag[:type] == true
+
+        record('info', 'reset', 'Server recovered! Resuming normal monitoring.')
+        @@rst_counter = 0
+        return
+      end
+    end
+
+    @@rst_counter += 1
+
+    unless Process.euid.zero?
+      record('error', 'reset', 'Permission denied: root required to manage systemd services.')
+      raise Errno::EPERM
+    end
+
+    record('info', 'reset', "Spawning 'systemctl restart minecraft' (PID will be captured)...")
+    pid = spawn 'systemctl restart minecraft'
+    record('debug', 'reset', "systemctl restart spawned with PID #{pid}.")
+    tick_beg = Time.now
+
+    # rubocop:disable Metrics/BlockLength
+    loop do
+      sleep 0.5
+      SystemdNotifier.notify('WATCHDOG=1')
+      proc_status = Process.waitpid2(pid, Process::WNOHANG)
+      if proc_status # 子进程已退出，返回 [pid, status]
+        _, status = proc_status
+        elapsed = (Time.now - tick_beg).round(2)
+        if status.success?
+          record('info', 'reset', "'systemctl restart' succeeded in #{elapsed}s.")
+          @@rst_counter = 0 # 成功时重置计数器
+        else
+          record('error', 'reset',
+                 "'systemctl restart' failed with exitcode #{status.exitstatus} after #{elapsed}s.")
+        end
+        break
+      else # 子进程仍在运行 (WNOHANG 返回 nil)
+        if Time.now - tick_beg > PERSISTENCE_PERIOD
+          record('warn', 'reset',
+                 "'systemctl restart' timed out after #{PERSISTENCE_PERIOD}s. Force-killing PID #{pid}...")
+          system "kill -9 #{pid}"
+          record('warn', 'reset', "Running 'systemctl kill minecraft' (last resort)...")
+          system 'systemctl kill minecraft' # 没招了，毁灭吧
+          sleep 0.5
+          record('info', 'reset', "Running 'systemctl start minecraft' (rebirth)...")
+          system 'systemctl start minecraft' # 重生
+          record('info', 'reset', 'Force-reset sequence completed.')
+          break
+        end
+      end
+      # rubocop:enable Metrics/BlockLength
+    end
+  end
+  # rubocop:enable Metrics/MethodLength, Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
+  # rubocop:enable Style/ClassVars
+end