require_relative '../helper'
require 'fluent/test/driver/input'
require 'fluent/plugin/in_tail'
require 'fluent/plugin/buffer'
require 'fluent/system_config'
require 'fluent/file_wrapper'
require 'net/http'
require 'flexmock/test_unit'
require 'timecop'
require 'tmpdir'
require 'securerandom'

class TailInputTest < Test::Unit::TestCase
  include FlexMock::TestCase

  def tmp_dir
    File.join(File.dirname(__FILE__), "..", "tmp", "tail#{ENV['TEST_ENV_NUMBER']}", SecureRandom.hex(10))
  end

  def setup
    Fluent::Test.setup
    @tmp_dir = tmp_dir
    cleanup_directory(@tmp_dir)
  end

  def teardown
    super
    cleanup_directory(@tmp_dir)
    Fluent::Engine.stop
    Timecop.return
  end

  def cleanup_directory(path)
    unless Dir.exist?(path)
      FileUtils.mkdir_p(path)
      return
    end

    FileUtils.remove_entry_secure(path, true)
  end

  def cleanup_file(path)
    FileUtils.remove_entry_secure(path, true)
  end

  def create_target_info(path)
    Fluent::Plugin::TailInput::TargetInfo.new(path, Fluent::FileWrapper.stat(path).ino)
  end

  ROOT_CONFIG = config_element("ROOT", "", {
                            "tag" => "t1",
                            "rotate_wait" => "2s",
                            "refresh_interval" => "1s"
                               })

  def base_config
    ROOT_CONFIG + config_element("", "", { "path" => "#{@tmp_dir}/tail.txt" })
  end

  def common_config
    base_config + config_element("", "", { "pos_file" => "#{@tmp_dir}/tail.pos" })
  end

  def common_follow_inode_config
    config_element("ROOT", "", {
                     "path" => "#{@tmp_dir}/tail.txt*",
                     "pos_file" => "#{@tmp_dir}/tail.pos",
                     "tag" => "t1",
                     "refresh_interval" => "1s",
                     "read_from_head" => "true",
                     "format" => "none",
                     "rotate_wait" => "1s",
                     "follow_inodes" => "true"
                   })
  end

  CONFIG_READ_FROM_HEAD = config_element("", "", { "read_from_head" => true })
  CONFIG_DISABLE_WATCH_TIMER = config_element("", "", { "enable_watch_timer" => false })
  CONFIG_DISABLE_STAT_WATCHER = config_element("", "", { "enable_stat_watcher" => false })
  CONFIG_OPEN_ON_EVERY_UPDATE = config_element("", "", { "open_on_every_update" => true })
  SINGLE_LINE_CONFIG = config_element("", "", { "format" => "/(?<message>.*)/" })
  PARSE_SINGLE_LINE_CONFIG = config_element("", "", {}, [config_element("parse", "", { "@type" => "/(?<message>.*)/" })])
  MULTILINE_CONFIG = config_element(
    "", "", {
      "format" => "multiline",
      "format1" => "/^s (?<message1>[^\\n]+)(\\nf (?<message2>[^\\n]+))?(\\nf (?<message3>.*))?/",
      "format_firstline" => "/^[s]/"
    })
  PARSE_MULTILINE_CONFIG = config_element(
    "", "", {},
    [config_element("parse", "", {
                      "@type" => "multiline",
                      "format1" => "/^s (?<message1>[^\\n]+)(\\nf (?<message2>[^\\n]+))?(\\nf (?<message3>.*))?/",
                      "format_firstline" => "/^[s]/"
                    })
    ])

  MULTILINE_CONFIG_WITH_NEWLINE = config_element(
    "", "", {
      "format" => "multiline",
      "format1" => "/^s (?<message1>[^\\n]+)(\\nf (?<message2>[^\\n]+))?(\\nf (?<message3>.[^\\n]+))?/",
      "format_firstline" => "/^[s]/"
    })
  PARSE_MULTILINE_CONFIG_WITH_NEWLINE = config_element(
    "", "", {},
    [config_element("parse", "", {
                      "@type" => "multiline",
                      "format1" => "/^s (?<message1>[^\\n]+)(\\nf (?<message2>[^\\n]+))?(\\nf (?<message3>.[^\\n]+))?/",
                      "format_firstline" => "/^[s]/"
                    })
    ])

  EX_ROTATE_WAIT = 0
  EX_FOLLOW_INODES = false

  def ex_config
    config_element("", "", {
                     "tag" => "tail",
                     "path" => "test/plugin/*/%Y/%m/%Y%m%d-%H%M%S.log,test/plugin/data/log/**/*.log",
                     "format" => "none",
                     "pos_file" => "#{@tmp_dir}/tail.pos",
                     "read_from_head" => true,
                     "refresh_interval" => 30,
                     "rotate_wait" => "#{EX_ROTATE_WAIT}s",
                     "follow_inodes" => "#{EX_FOLLOW_INODES}",
                   })
  end

  def tailing_group_pattern
    "/#{@tmp_dir}\/(?<podname>[a-z0-9]([-a-z0-9]*[a-z0-9])?(\/[a-z0-9]([-a-z0-9]*[a-z0-9])?)*)_(?<namespace>[^_]+)_(?<container>.+)-(?<docker_id>[a-z0-9]{6})\.log$/"
  end

  DEBUG_LOG_LEVEL = config_element("", "", {
    "@log_level" => "debug"
  })

  def create_group_directive(pattern, rate_period, *rules)
    config_element("", "", {}, [
      config_element("group", "", {
        "pattern" => pattern,
        "rate_period" => rate_period
      }, rules)
    ])
  end

  def create_rule_directive(match_named_captures, limit)
    params = {
      "limit" => limit,
      "match" => match_named_captures,
    }

    config_element("rule", "", params)
  end

  def create_path_element(path)
    config_element("source", "", { "path" => "#{@tmp_dir}/#{path}" })
  end

  def create_driver(conf = SINGLE_LINE_CONFIG, use_common_conf = true)
    config = use_common_conf ? common_config + conf : conf
    Fluent::Test::Driver::Input.new(Fluent::Plugin::TailInput).configure(config)
  end

  sub_test_case "configure" do
    test "plain single line" do
      d = create_driver
      assert_equal(["#{@tmp_dir}/tail.txt"], d.instance.paths)
      assert_equal("t1", d.instance.tag)
      assert_equal(2, d.instance.rotate_wait)
      assert_equal("#{@tmp_dir}/tail.pos", d.instance.pos_file)
      assert_equal(1000, d.instance.read_lines_limit)
      assert_equal(-1, d.instance.read_bytes_limit_per_second)
      assert_equal(false, d.instance.ignore_repeated_permission_error)
      assert_nothing_raised do
        d.instance.have_read_capability?
      end
    end

    data("empty" => config_element,
         "w/o @type" => config_element("", "", {}, [config_element("parse", "", {})]))
    test "w/o parse section" do |conf|
      assert_raise(Fluent::ConfigError) do
        create_driver(conf)
      end
    end

    test "multi paths with path_delimiter" do
      c = config_element("ROOT", "", { "path" => "tail.txt|test2|tmp,dev", "tag" => "t1", "path_delimiter" => "|" })
      d = create_driver(c + PARSE_SINGLE_LINE_CONFIG, false)
      assert_equal(["tail.txt", "test2", "tmp,dev"], d.instance.paths)
    end

    test "multi paths with same path configured twice" do
      c = config_element("ROOT", "", { "path" => "test1.txt,test2.txt,test1.txt", "tag" => "t1", "path_delimiter" => "," })
      d = create_driver(c + PARSE_SINGLE_LINE_CONFIG, false)
      assert_equal(["test2.txt","test1.txt"].sort, d.instance.paths.sort)
    end

    test "multi paths with invaid path_delimiter" do
      c = config_element("ROOT", "", { "path" => "tail.txt|test2|tmp,dev", "tag" => "t1", "path_delimiter" => "*" })
      assert_raise(Fluent::ConfigError) do
        create_driver(c + PARSE_SINGLE_LINE_CONFIG, false)
      end
    end

    test "follow_inodes w/o pos file" do
      assert_raise(Fluent::ConfigError) do
        create_driver(base_config + config_element('', '', {'follow_inodes' => 'true'}))
      end
    end

    sub_test_case "log throttling per file" do
      test "w/o watcher timer is invalid" do
        conf = CONFIG_DISABLE_WATCH_TIMER + config_element("ROOT", "", {"read_bytes_limit_per_second" => "8k"})
        assert_raise(Fluent::ConfigError) do
          create_driver(conf)
        end
      end

      test "valid" do
        conf = config_element("ROOT", "", {"read_bytes_limit_per_second" => "8k"})
        assert_raise(Fluent::ConfigError) do
          create_driver(conf)
        end
      end
    end

    test "both enable_watch_timer and enable_stat_watcher are false" do
      assert_raise(Fluent::ConfigError) do
        create_driver(CONFIG_DISABLE_WATCH_TIMER + CONFIG_DISABLE_STAT_WATCHER + PARSE_SINGLE_LINE_CONFIG)
      end
    end

    sub_test_case "encoding" do
      test "valid" do
        conf = SINGLE_LINE_CONFIG + config_element("", "", { "encoding" => "utf-8" })
        d = create_driver(conf)
        assert_equal(Encoding::UTF_8, d.instance.encoding)
      end

      test "invalid" do
        conf = SINGLE_LINE_CONFIG + config_element("", "", { "encoding" => "no-such-encoding" })
        assert_raise(Fluent::ConfigError) do
          create_driver(conf)
        end
      end
    end

    sub_test_case "from_encoding" do
      test "only specified from_encoding raise ConfigError" do
        conf = SINGLE_LINE_CONFIG + config_element("", "", { "from_encoding" => "utf-8" })
        assert_raise(Fluent::ConfigError) do
          create_driver(conf)
        end
      end

      test "valid" do
        conf = SINGLE_LINE_CONFIG + config_element("", "", {
                                                     "from_encoding" => "utf-8",
                                                     "encoding" => "utf-8"
                                                   })
        d = create_driver(conf)
        assert_equal(Encoding::UTF_8, d.instance.from_encoding)
      end

      test "invalid" do
        conf = SINGLE_LINE_CONFIG + config_element("", "", {
                                                     "from_encoding" => "no-such-encoding",
                                                     "encoding" => "utf-8"
                                                   })
        assert_raise(Fluent::ConfigError) do
          create_driver(conf)
        end
      end
    end
  end

  sub_test_case "configure group" do
    test "<rule> required" do
      conf = create_group_directive('.', '1m') + SINGLE_LINE_CONFIG
      assert_raise(Fluent::ConfigError) do
        create_driver(conf)
      end
    end

    test "valid configuration" do
      rule1 = create_rule_directive({
        "namespace"=> "/namespace-a/",
        "podname"=> "/podname-[b|c]/"
      }, 100)
      rule2 = create_rule_directive({
        "namespace"=> "/namespace-[d|e]/",
        "podname"=> "/podname-f/",
      }, 50)
      rule3 = create_rule_directive({
        "podname"=> "/podname-g/",
      }, -1)
      rule4 = create_rule_directive({
        "namespace"=> "/namespace-h/",
      }, 0)

      conf = create_group_directive(tailing_group_pattern, '1m', rule1, rule2, rule3, rule4) + SINGLE_LINE_CONFIG
      assert_nothing_raised do
        create_driver(conf)
      end
    end

    test "limit should be greater than DEFAULT_LIMIT (-1)" do
      rule1 = create_rule_directive({
        "namespace"=> "/namespace-a/",
        "podname"=> "/podname-[b|c]/",
      }, -100)
      rule2 = create_rule_directive({
        "namespace"=> "/namespace-[d|e]/",
        "podname"=> "/podname-f/",
      }, 50)
      conf = create_group_directive(tailing_group_pattern, '1m', rule1, rule2) + SINGLE_LINE_CONFIG
      assert_raise(RuntimeError) do
        create_driver(conf)
      end
    end
  end

  sub_test_case "group rules line limit resolution" do
    test "valid" do
      rule1 = create_rule_directive({
        "namespace"=> "/namespace-a/",
        "podname"=> "/podname-[b|c]/",
      }, 50)
      rule2 = create_rule_directive({
        "podname"=> "/podname-[b|c]/",
      }, 400)
      rule3 = create_rule_directive({
        "namespace"=> "/namespace-a/",
      }, 100)

      conf = create_group_directive(tailing_group_pattern, '1m', rule3, rule1, rule2) + SINGLE_LINE_CONFIG
      assert_nothing_raised do
        d = create_driver(conf)
        instance = d.instance

        metadata = {
          "namespace"=> "namespace-a",
          "podname"=> "podname-b",
        }
        assert_equal(50, instance.find_group(metadata).limit)

        metadata = {
          "namespace" => "namespace-a",
          "podname" => "podname-c",
        }
        assert_equal(50, instance.find_group(metadata).limit)

        metadata = {
          "namespace" => "namespace-a",
          "podname" => "podname-d",
        }
        assert_equal(100, instance.find_group(metadata).limit)

        metadata = {
          "namespace" => "namespace-f",
          "podname" => "podname-b",
        }
        assert_equal(400, instance.find_group(metadata).limit)

        metadata = {
          "podname" => "podname-c",
        }
        assert_equal(400, instance.find_group(metadata).limit)

        assert_equal(-1, instance.find_group({}).limit)
      end
    end
  end

  sub_test_case "files should be placed in groups" do
    test "invalid regex pattern places files in default group" do
      rule1 = create_rule_directive({}, 100) ## limits default groups
      conf = ROOT_CONFIG + DEBUG_LOG_LEVEL + create_group_directive(tailing_group_pattern, '1m', rule1) + create_path_element("test*.txt") + SINGLE_LINE_CONFIG

      d = create_driver(conf, false)
      Fluent::FileWrapper.open("#{@tmp_dir}/test1.txt", 'w')
      Fluent::FileWrapper.open("#{@tmp_dir}/test2.txt", 'w')
      Fluent::FileWrapper.open("#{@tmp_dir}/test3.txt", 'w')

      d.run do
        ## checking default group_watcher's paths
        instance = d.instance
        key = instance.default_group_key

        assert_equal(3, instance.log.logs.count{|a| a.match?("Cannot find group from metadata, Adding file in the default group\n")})
        assert_equal(3, instance.group_watchers[key].size)
        assert_true(instance.group_watchers[key].include? File.join(@tmp_dir, 'test1.txt'))
        assert_true(instance.group_watchers[key].include? File.join(@tmp_dir, 'test2.txt'))
        assert_true(instance.group_watchers[key].include? File.join(@tmp_dir, 'test3.txt'))
      end
    end

    test "valid regex pattern places file in their respective groups" do
      rule1 = create_rule_directive({
        "namespace"=> "/test-namespace1/",
        "podname"=> "/test-podname1/",
      }, 100)
      rule2 = create_rule_directive({
        "namespace"=> "/test-namespace1/",
      }, 200)
      rule3 = create_rule_directive({
        "podname"=> "/test-podname2/",
      }, 300)
      rule4 = create_rule_directive({}, 400)

      path_element = create_path_element("test-podname*.log")

      conf = ROOT_CONFIG + create_group_directive(tailing_group_pattern, '1m', rule4, rule3, rule2, rule1) + path_element + SINGLE_LINE_CONFIG
      d = create_driver(conf, false)

      file1 = File.join(@tmp_dir, "test-podname1_test-namespace1_test-container-15fabq.log")
      file2 = File.join(@tmp_dir, "test-podname3_test-namespace1_test-container-15fabq.log")
      file3 = File.join(@tmp_dir, "test-podname2_test-namespace2_test-container-15fabq.log")
      file4 = File.join(@tmp_dir, "test-podname4_test-namespace3_test-container-15fabq.log")

      d.run do
        Fluent::FileWrapper.open(file1, 'w')
        Fluent::FileWrapper.open(file2, 'w')
        Fluent::FileWrapper.open(file3, 'w')
        Fluent::FileWrapper.open(file4, 'w')

        instance = d.instance
        assert_equal(100, instance.find_group_from_metadata(file1).limit)
        assert_equal(200, instance.find_group_from_metadata(file2).limit)
        assert_equal(300, instance.find_group_from_metadata(file3).limit)
        assert_equal(400, instance.find_group_from_metadata(file4).limit)
      end
    end
  end

  sub_test_case "singleline" do
    data(flat: SINGLE_LINE_CONFIG,
         parse: PARSE_SINGLE_LINE_CONFIG)
    def test_emit(data)
      config = data
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f|
        f.puts "test1"
        f.puts "test2"
      }

      d = create_driver(config)

      d.run(expect_emits: 1) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f|
          f.puts "test3\ntest4"
        }
      end

      events = d.events
      assert_equal(true, events.length > 0)
      assert_equal({"message" => "test3"}, events[0][2])
      assert_equal({"message" => "test4"}, events[1][2])
      assert(events[0][1].is_a?(Fluent::EventTime))
      assert(events[1][1].is_a?(Fluent::EventTime))
      assert_equal(1, d.emit_count)
    end

    def test_emit_with_emit_unmatched_lines_true
      config = config_element("", "", { "format" => "/^(?<message>test.*)/", "emit_unmatched_lines" => true })
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") { |f| }

      d = create_driver(config)
      d.run(expect_emits: 1) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f|
          f.puts "test line 1"
          f.puts "test line 2"
          f.puts "bad line 1"
          f.puts "test line 3"
        }
      end

      events = d.events
      assert_equal(4, events.length)
      assert_equal({"message" => "test line 1"}, events[0][2])
      assert_equal({"message" => "test line 2"}, events[1][2])
      assert_equal({"unmatched_line" => "bad line 1"}, events[2][2])
      assert_equal({"message" => "test line 3"}, events[3][2])
    end

    data('flat 1' => [:flat, 1, 2],
         'flat 10' => [:flat, 10, 1],
         'parse 1' => [:parse, 1, 2],
         'parse 10' => [:parse, 10, 1])
    def test_emit_with_read_lines_limit(data)
      config_style, limit, num_events = data
      case config_style
      when :flat
        config = CONFIG_READ_FROM_HEAD + SINGLE_LINE_CONFIG + config_element("", "", { "read_lines_limit" => limit })
      when :parse
        config = CONFIG_READ_FROM_HEAD + config_element("", "", { "read_lines_limit" => limit }) + PARSE_SINGLE_LINE_CONFIG
      end
      d = create_driver(config)
      msg = 'test' * 2000 # in_tail reads 8192 bytes at once.

      d.run(expect_emits: num_events, timeout: 2) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f|
          f.puts msg
          f.puts msg
        }
      end

      events = d.events
      assert_equal(true, events.length > 0)
      assert_equal({"message" => msg}, events[0][2])
      assert_equal({"message" => msg}, events[1][2])
      assert num_events <= d.emit_count
    end

    sub_test_case "log throttling per file" do
      teardown do
        cleanup_file("#{@tmp_dir}/tail.txt")
      end

      sub_test_case "reads_bytes_per_second w/o throttled" do
        data("flat 8192 bytes, 2 events"        => [:flat, 100, 8192, 2],
             "flat 8192 bytes, 2 events w/o stat watcher" => [:flat_without_stat, 100, 8192, 2],
             "flat #{8192*10} bytes, 20 events"  => [:flat, 100, (8192 * 10), 20],
             "flat #{8192*10} bytes, 20 events w/o stat watcher"  => [:flat_without_stat, 100, (8192 * 10), 20],
             "parse #{8192*4} bytes, 8 events"  => [:parse, 100, (8192 * 4), 8],
             "parse #{8192*4} bytes, 8 events w/o stat watcher"  => [:parse_without_stat, 100, (8192 * 4), 8],
             "parse #{8192*10} bytes, 20 events" => [:parse, 100, (8192 * 10), 20],
             "parse #{8192*10} bytes, 20 events w/o stat watcher" => [:parse_without_stat, 100, (8192 * 10), 20],
             "flat 8k bytes with unit, 2 events" => [:flat, 100, "8k", 2])
        def test_emit_with_read_bytes_limit_per_second(data)
          config_style, limit, limit_bytes, num_events = data
          case config_style
          when :flat
            config = CONFIG_READ_FROM_HEAD + SINGLE_LINE_CONFIG + config_element("", "", { "read_lines_limit" => limit, "read_bytes_limit_per_second" => limit_bytes })
          when :parse
            config = CONFIG_READ_FROM_HEAD + config_element("", "", { "read_lines_limit" => limit, "read_bytes_limit_per_second" => limit_bytes }) + PARSE_SINGLE_LINE_CONFIG
          when :flat_without_stat
            config = CONFIG_READ_FROM_HEAD + SINGLE_LINE_CONFIG + CONFIG_DISABLE_STAT_WATCHER + config_element("", "", { "read_lines_limit" => limit, "read_bytes_limit_per_second" => limit_bytes })
          when :parse_without_stat
            config = CONFIG_READ_FROM_HEAD + CONFIG_DISABLE_STAT_WATCHER + config_element("", "", { "read_lines_limit" => limit, "read_bytes_limit_per_second" => limit_bytes }) + PARSE_SINGLE_LINE_CONFIG
          end

          msg = 'test' * 2000 # in_tail reads 8192 bytes at once.
          start_time = Fluent::Clock.now

          d = create_driver(config)
          d.run(expect_emits: 2) do
            Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f|
              100.times do
                f.puts msg
              end
            }
          end

          assert_true(Fluent::Clock.now - start_time > 1)
          assert_equal(num_events.times.map { {"message" => msg} },
                       d.events.collect { |event| event[2] })
        end

        def test_read_bytes_limit_precede_read_lines_limit
          config = CONFIG_READ_FROM_HEAD +
                   SINGLE_LINE_CONFIG +
                   config_element("", "", {
                                    "read_lines_limit" => 1000,
                                    "read_bytes_limit_per_second" => 8192
                                  })
          msg = 'abc'
          start_time = Fluent::Clock.now
          d = create_driver(config)
          d.run(expect_emits: 2) do
            Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f|
              8000.times do
                f.puts msg
              end
            }
          end

          assert_true(Fluent::Clock.now - start_time > 1)
          assert_equal(4096.times.map { {"message" => msg} },
                       d.events.collect { |event| event[2] })
        end
      end

      sub_test_case "reads_bytes_per_second w/ throttled already" do
        data("flat 8192 bytes"  => [:flat, 100, 8192],
             "parse 8192 bytes" => [:parse, 100, 8192])
        def test_emit_with_read_bytes_limit_per_second(data)
          config_style, limit, limit_bytes = data
          case config_style
          when :flat
            config = CONFIG_READ_FROM_HEAD + SINGLE_LINE_CONFIG + config_element("", "", { "read_lines_limit" => limit, "read_bytes_limit_per_second" => limit_bytes })
          when :parse
            config = CONFIG_READ_FROM_HEAD + config_element("", "", { "read_lines_limit" => limit, "read_bytes_limit_per_second" => limit_bytes }) + PARSE_SINGLE_LINE_CONFIG
          end
          d = create_driver(config)
          msg = 'test' * 2000 # in_tail reads 8192 bytes at once.

          mock.proxy(d.instance).io_handler(anything, anything) do |io_handler|
            require 'fluent/config/types'
            limit_bytes_value = Fluent::Config.size_value(limit_bytes)
            io_handler.instance_variable_set(:@number_bytes_read, limit_bytes_value)
            if Fluent.linux?
              mock.proxy(io_handler).handle_notify.at_least(5)
            else
              mock.proxy(io_handler).handle_notify.twice
            end
            io_handler
          end

          Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") do |f|
            100.times do
              f.puts msg
            end
          end

          # We should not do shutdown here due to hard timeout.
          d.run do
            start_time = Fluent::Clock.now
            while Fluent::Clock.now - start_time < 0.8 do
              Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") do |f|
                f.puts msg
                f.flush
              end
              sleep 0.05
            end
          end

          assert_equal([], d.events)
        end
      end

      sub_test_case "EOF with reads_bytes_per_second" do
        def test_longer_than_rotate_wait
          limit_bytes = 8192
          num_lines = 1024 * 3
          msg = "08bytes"

          Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") do |f|
            f.write("#{msg}\n" * num_lines)
          end

          config = CONFIG_READ_FROM_HEAD +
                   SINGLE_LINE_CONFIG +
                   config_element("", "", {
                                    "read_bytes_limit_per_second" => limit_bytes,
                                    "rotate_wait" => 0.1,
                                    "refresh_interval" => 0.5,
                                  })

          rotated = false
          d = create_driver(config)
          d.run(timeout: 10) do
            while d.events.size < num_lines do
              if d.events.size > 0 && !rotated
                cleanup_file("#{@tmp_dir}/tail.txt")
                FileUtils.touch("#{@tmp_dir}/tail.txt")
                rotated = true
              end
              sleep 0.3
            end
          end

          assert_equal(num_lines,
                       d.events.count do |event|
                         event[2]["message"] == msg
                       end)
        end

        def test_shorter_than_rotate_wait
          limit_bytes = 8192
          num_lines = 1024 * 2
          msg = "08bytes"

          Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") do |f|
            f.write("#{msg}\n" * num_lines)
          end

          config = CONFIG_READ_FROM_HEAD +
                   SINGLE_LINE_CONFIG +
                   config_element("", "", {
                                    "read_bytes_limit_per_second" => limit_bytes,
                                    "rotate_wait" => 2,
                                    "refresh_interval" => 0.5,
                                  })

          start_time = Fluent::Clock.now
          rotated = false
          detached = false
          d = create_driver(config)
          mock.proxy(d.instance).setup_watcher(anything, anything) do |tw|
            mock.proxy(tw).detach(anything) do |v|
              detached = true
              v
            end
            tw
          end.twice

          d.run(timeout: 10) do
            until detached do
              if d.events.size > 0 && !rotated
                cleanup_file("#{@tmp_dir}/tail.txt")
                FileUtils.touch("#{@tmp_dir}/tail.txt")
                rotated = true
              end
              sleep 0.3
            end
          end

          assert_true(Fluent::Clock.now - start_time > 2)
          assert_equal(num_lines,
                       d.events.count do |event|
                         event[2]["message"] == msg
                       end)
        end
      end
    end

    data(flat: CONFIG_READ_FROM_HEAD + SINGLE_LINE_CONFIG,
         parse: CONFIG_READ_FROM_HEAD + PARSE_SINGLE_LINE_CONFIG)
    def test_emit_with_read_from_head(data)
      config = data
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f|
        f.puts "test1"
        f.puts "test2"
      }

      d = create_driver(config)

      d.run(expect_emits: 2) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f|
          f.puts "test3"
          f.puts "test4"
        }
      end

      events = d.events
      assert(events.length > 0)
      assert_equal({"message" => "test1"}, events[0][2])
      assert_equal({"message" => "test2"}, events[1][2])
      assert_equal({"message" => "test3"}, events[2][2])
      assert_equal({"message" => "test4"}, events[3][2])
    end

    data(flat: CONFIG_DISABLE_WATCH_TIMER + SINGLE_LINE_CONFIG,
         parse: CONFIG_DISABLE_WATCH_TIMER + PARSE_SINGLE_LINE_CONFIG)
    def test_emit_without_watch_timer(data)
      config = data
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f|
        f.puts "test1"
        f.puts "test2"
      }

      d = create_driver(config)

      d.run(expect_emits: 1) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f|
          f.puts "test3"
          f.puts "test4"
        }
        # according to cool.io's stat_watcher.c, systems without inotify will use
        # an "automatic" value, typically around 5 seconds
      end

      events = d.events
      assert(events.length > 0)
      assert_equal({"message" => "test3"}, events[0][2])
      assert_equal({"message" => "test4"}, events[1][2])
    end

    # https://github.com/fluent/fluentd/pull/3541#discussion_r740197711
    def test_watch_wildcard_path_without_watch_timer
      omit "need inotify" unless Fluent.linux?

      config = config_element("ROOT", "", {
                                "path" => "#{@tmp_dir}/tail*.txt",
                                "tag" => "t1",
                              })
      config = config + CONFIG_DISABLE_WATCH_TIMER + SINGLE_LINE_CONFIG

      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f|
        f.puts "test1"
        f.puts "test2"
      }

      d = create_driver(config, false)

      d.run(expect_emits: 1, timeout: 1) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f|
          f.puts "test3"
          f.puts "test4"
        }
      end

      assert_equal(
        [
          {"message" => "test3"},
          {"message" => "test4"},
        ],
        d.events.collect { |event| event[2] })
    end

    data(flat: CONFIG_DISABLE_STAT_WATCHER + SINGLE_LINE_CONFIG,
         parse: CONFIG_DISABLE_STAT_WATCHER + PARSE_SINGLE_LINE_CONFIG)
    def test_emit_with_disable_stat_watcher(data)
      config = data
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f|
        f.puts "test1"
        f.puts "test2"
      }

      d = create_driver(config)

      d.run(expect_emits: 1) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f|
          f.puts "test3"
          f.puts "test4"
        }
      end

      events = d.events
      assert(events.length > 0)
      assert_equal({"message" => "test3"}, events[0][2])
      assert_equal({"message" => "test4"}, events[1][2])
    end

    def test_always_read_from_head_on_detecting_a_new_file
      d = create_driver(SINGLE_LINE_CONFIG)

      d.run(expect_emits: 1, timeout: 3) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f|
          f.puts "test1\ntest2\n"
        }
      end

      assert_equal(
        [
          {"message" => "test1"},
          {"message" => "test2"},
        ],
        d.events.collect { |event| event[2] })
    end
  end

  class TestWithSystem < self
    include Fluent::SystemConfig::Mixin

    OVERRIDE_FILE_PERMISSION = 0620
    CONFIG_SYSTEM = %[
      <system>
        file_permission #{OVERRIDE_FILE_PERMISSION}
      </system>
    ]

    def setup
      omit "NTFS doesn't support UNIX like permissions" if Fluent.windows?
      super
      # Store default permission
      @default_permission = system_config.instance_variable_get(:@file_permission)
    end

    def teardown
      return if Fluent.windows?
      super
      # Restore default permission
      system_config.instance_variable_set(:@file_permission, @default_permission)
    end

    def parse_system(text)
      basepath = File.expand_path(File.dirname(__FILE__) + '/../../')
      Fluent::Config.parse(text, '(test)', basepath, true).elements.find { |e| e.name == 'system' }
    end

    def test_emit_with_system
      system_conf = parse_system(CONFIG_SYSTEM)
      sc = Fluent::SystemConfig.new(system_conf)
      Fluent::Engine.init(sc)
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f|
        f.puts "test1"
        f.puts "test2"
      }

      d = create_driver

      d.run(expect_emits: 1) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f|
          f.puts "test3"
          f.puts "test4"
        }
      end

      events = d.events
      assert_equal(true, events.length > 0)
      assert_equal({"message" => "test3"}, events[0][2])
      assert_equal({"message" => "test4"}, events[1][2])
      assert(events[0][1].is_a?(Fluent::EventTime))
      assert(events[1][1].is_a?(Fluent::EventTime))
      assert_equal(1, d.emit_count)
      pos = d.instance.instance_variable_get(:@pf_file)
      mode = "%o" % File.stat(pos).mode
      assert_equal OVERRIDE_FILE_PERMISSION, mode[-3, 3].to_i
    end
  end

  sub_test_case "rotate file" do
    def create_driver(conf = SINGLE_LINE_CONFIG)
      config = common_config + conf
      Fluent::Test::Driver::Input.new(Fluent::Plugin::TailInput).configure(config)
    end

    data(flat: SINGLE_LINE_CONFIG,
         parse: PARSE_SINGLE_LINE_CONFIG)
    def test_rotate_file(data)
      config = data
      events = sub_test_rotate_file(config, expect_emits: 2)
      assert_equal(3.upto(6).collect { |i| {"message" => "test#{i}"} },
                   events.collect { |event| event[2] })
    end

    data(flat: CONFIG_READ_FROM_HEAD + SINGLE_LINE_CONFIG,
         parse: CONFIG_READ_FROM_HEAD + PARSE_SINGLE_LINE_CONFIG)
    def test_rotate_file_with_read_from_head(data)
      config = data
      events = sub_test_rotate_file(config, expect_records: 6)
      assert_equal(1.upto(6).collect { |i| {"message" => "test#{i}"} },
                   events.collect { |event| event[2] })
    end

    data(flat: CONFIG_OPEN_ON_EVERY_UPDATE + CONFIG_READ_FROM_HEAD + SINGLE_LINE_CONFIG,
         parse: CONFIG_OPEN_ON_EVERY_UPDATE + CONFIG_READ_FROM_HEAD + PARSE_SINGLE_LINE_CONFIG)
    def test_rotate_file_with_open_on_every_update(data)
      config = data
      events = sub_test_rotate_file(config, expect_records: 6)
      assert_equal(1.upto(6).collect { |i| {"message" => "test#{i}"} },
                   events.collect { |event| event[2] })
    end

    data(flat: SINGLE_LINE_CONFIG,
         parse: PARSE_SINGLE_LINE_CONFIG)
    def test_rotate_file_with_write_old(data)
      config = data
      events = sub_test_rotate_file(config, expect_emits: 3) { |rotated_file|
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") { |f| }
        rotated_file.puts "test7"
        rotated_file.puts "test8"
        rotated_file.flush

        sleep 1
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") { |f|
          f.puts "test5"
          f.puts "test6"
        }
      }
      # This test sometimes fails and it shows a potential bug of in_tail
      # https://github.com/fluent/fluentd/issues/1434
      assert_equal([3, 4, 7, 8, 5, 6].collect { |i| {"message" => "test#{i}"} },
                   events.collect { |event| event[2] })
    end

    data(flat: SINGLE_LINE_CONFIG,
         parse: PARSE_SINGLE_LINE_CONFIG)
    def test_rotate_file_with_write_old_and_no_new_file(data)
      config = data
      events = sub_test_rotate_file(config, expect_emits: 2) { |rotated_file|
        rotated_file.puts "test7"
        rotated_file.puts "test8"
        rotated_file.flush
      }
      assert_equal([3, 4, 7, 8].collect { |i| {"message" => "test#{i}"} },
                   events.collect { |event| event[2] })
    end

    def sub_test_rotate_file(config = nil, expect_emits: nil, expect_records: nil, timeout: 5)
      file = Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb")
      file.puts "test1"
      file.puts "test2"
      file.flush

      d = create_driver(config)
      d.run(expect_emits: expect_emits, expect_records: expect_records, timeout: timeout) do
        sleep(0.1) while d.instance.instance_variable_get(:@startup)
        size = d.emit_count
        file.puts "test3"
        file.puts "test4"
        file.flush
        sleep(0.1) until d.emit_count >= size + 1
        size = d.emit_count

        if Fluent.windows?
          file.close
          FileUtils.mv("#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail2.txt", force: true)
          file = Fluent::FileWrapper.open("#{@tmp_dir}/tail2.txt", "ab")
        else
          FileUtils.mv("#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail2.txt")
        end
        if block_given?
          yield file
        else
          Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") { |f| }
          sleep 1

          Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") { |f|
            f.puts "test5"
            f.puts "test6"
          }
        end
      end

      d.events
    ensure
      file.close if file && !file.closed?
    end
  end

  def test_truncate_file
    config = SINGLE_LINE_CONFIG
    Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f|
      f.puts "test1"
      f.puts "test2"
      f.flush
    }

    d = create_driver(config)

    d.run(expect_emits: 2) do
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f|
        f.puts "test3\ntest4"
        f.flush
      }
      waiting(2) { sleep 0.1 until d.events.length == 2 }
      if Fluent.windows?
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") { |f|
          f.puts("test1");
        }
      else
        File.truncate("#{@tmp_dir}/tail.txt", 6)
      end
    end

    expected = {
      emit_count: 2,
      events: [
        [Fluent::EventTime, {"message" => "test3"}],
        [Fluent::EventTime, {"message" => "test4"}],
        [Fluent::EventTime, {"message" => "test1"}],
      ]
    }
    actual = {
      emit_count: d.emit_count,
      events: d.events.collect{|event| [event[1].class, event[2]]}
    }
    assert_equal(expected, actual)
  end

  def test_move_truncate_move_back
    config = SINGLE_LINE_CONFIG
    Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f|
      f.puts "test1"
      f.puts "test2"
    }

    d = create_driver(config)

    d.run(expect_emits: 1) do
      if Fluent.windows?
        FileUtils.mv("#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail2.txt", force: true)
      else
        FileUtils.mv("#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail2.txt")
      end
      sleep(1)
      if Fluent.windows?
        Fluent::FileWrapper.open("#{@tmp_dir}/tail2.txt", "wb") { |f|
          f.puts("test1");
        }
      else
        File.truncate("#{@tmp_dir}/tail2.txt", 6)
      end
      sleep(1)
      if Fluent.windows?
        FileUtils.mv("#{@tmp_dir}/tail2.txt", "#{@tmp_dir}/tail.txt", force: true)
      else
        FileUtils.mv("#{@tmp_dir}/tail2.txt", "#{@tmp_dir}/tail.txt")
      end
    end

    events = d.events
    assert_equal(1, events.length)
    assert_equal({"message" => "test1"}, events[0][2])
    assert(events[0][1].is_a?(Fluent::EventTime))
    assert_equal(1, d.emit_count)
  end

  def test_lf
    Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f| }

    d = create_driver

    d.run(expect_emits: 1) do
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f|
        f.print "test3"
      }
      sleep 1

      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f|
        f.puts "test4"
      }
    end

    events = d.events
    assert_equal(true, events.length > 0)
    assert_equal({"message" => "test3test4"}, events[0][2])
  end

  def test_whitespace
    Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f| }

    d = create_driver

    d.run(expect_emits: 1) do
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f|
        f.puts "    "		# 4 spaces
        f.puts "    4 spaces"
        f.puts "4 spaces    "
        f.puts "	"	# tab
        f.puts "	tab"
        f.puts "tab	"
      }
    end

    events = d.events
    assert_equal(true, events.length > 0)
    assert_equal({"message" => "    "}, events[0][2])
    assert_equal({"message" => "    4 spaces"}, events[1][2])
    assert_equal({"message" => "4 spaces    "}, events[2][2])
    assert_equal({"message" => "	"}, events[3][2])
    assert_equal({"message" => "	tab"}, events[4][2])
    assert_equal({"message" => "tab	"}, events[5][2])
  end

  data(
    'flat default encoding' => [SINGLE_LINE_CONFIG, Encoding::ASCII_8BIT],
    'flat explicit encoding config' => [SINGLE_LINE_CONFIG + config_element("", "", { "encoding" => "utf-8" }), Encoding::UTF_8],
    'parse default encoding' => [PARSE_SINGLE_LINE_CONFIG, Encoding::ASCII_8BIT],
    'parse explicit encoding config' => [PARSE_SINGLE_LINE_CONFIG + config_element("", "", { "encoding" => "utf-8" }), Encoding::UTF_8])
  def test_encoding(data)
    encoding_config, encoding = data

    d = create_driver(CONFIG_READ_FROM_HEAD + encoding_config)

    d.run(expect_emits: 1) do
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f|
        f.puts "test"
      }
    end

    events = d.events
    assert_equal(encoding, events[0][2]['message'].encoding)
  end

  def test_from_encoding
    conf = config_element(
      "", "", {
        "format" => "/(?<message>.*)/",
        "read_from_head" => "true",
        "from_encoding" => "cp932",
        "encoding" => "utf-8"
      })
    d = create_driver(conf)
    cp932_message = "\x82\xCD\x82\xEB\x81\x5B\x82\xED\x81\x5B\x82\xE9\x82\xC7".force_encoding(Encoding::CP932)
    utf8_message = cp932_message.encode(Encoding::UTF_8)

    d.run(expect_emits: 1) do
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "w:cp932") {|f|
        f.puts cp932_message
      }
    end

    events = d.events
    assert_equal(utf8_message, events[0][2]['message'])
    assert_equal(Encoding::UTF_8, events[0][2]['message'].encoding)
  end

  def test_from_encoding_utf16
    conf = config_element(
      "", "", {
        "format" => "/(?<message>.*)/",
        "read_from_head" => "true",
        "from_encoding" => "utf-16le",
        "encoding" => "utf-8"
      })
    d = create_driver(conf)
    utf16_message = "\u306F\u308D\u30FC\u308F\u30FC\u308B\u3069\n".encode(Encoding::UTF_16LE)
    utf8_message = utf16_message.encode(Encoding::UTF_8).strip

    d.run(expect_emits: 1) do
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "w:utf-16le") { |f|
        f.write utf16_message
      }
    end

    events = d.events
    assert_equal(utf8_message, events[0][2]['message'])
    assert_equal(Encoding::UTF_8, events[0][2]['message'].encoding)
  end

  def test_encoding_with_bad_character
    conf = config_element(
      "", "", {
        "format" => "/(?<message>.*)/",
        "read_from_head" => "true",
        "from_encoding" => "ASCII-8BIT",
        "encoding" => "utf-8"
      })
    d = create_driver(conf)

    d.run(expect_emits: 1) do
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "w") { |f|
        f.write "te\x86st\n"
      }
    end

    events = d.events
    assert_equal("te\uFFFDst", events[0][2]['message'])
    assert_equal(Encoding::UTF_8, events[0][2]['message'].encoding)
  end

  sub_test_case "multiline" do
    data(flat: MULTILINE_CONFIG,
         parse: PARSE_MULTILINE_CONFIG)
    def test_multiline(data)
      config = data
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") { |f| }

      d = create_driver(config)
      d.run(expect_emits: 1) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") { |f|
          f.puts "f test1"
          f.puts "s test2"
          f.puts "f test3"
          f.puts "f test4"
          f.puts "s test5"
          f.puts "s test6"
          f.puts "f test7"
          f.puts "s test8"
        }
      end

      events = d.events
      assert_equal(4, events.length)
      assert_equal({"message1" => "test2", "message2" => "test3", "message3" => "test4"}, events[0][2])
      assert_equal({"message1" => "test5"}, events[1][2])
      assert_equal({"message1" => "test6", "message2" => "test7"}, events[2][2])
      assert_equal({"message1" => "test8"}, events[3][2])
    end

    data(flat: MULTILINE_CONFIG,
         parse: PARSE_MULTILINE_CONFIG)
    def test_multiline_with_emit_unmatched_lines_true(data)
      config = data + config_element("", "", { "emit_unmatched_lines" => true })
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") { |f| }

      d = create_driver(config)
      d.run(expect_emits: 1) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") { |f|
          f.puts "f test1"
          f.puts "s test2"
          f.puts "f test3"
          f.puts "f test4"
          f.puts "s test5"
          f.puts "s test6"
          f.puts "f test7"
          f.puts "s test8"
        }
      end

      events = d.events
      assert_equal(5, events.length)
      assert_equal({"unmatched_line" => "f test1"}, events[0][2])
      assert_equal({"message1" => "test2", "message2" => "test3", "message3" => "test4"}, events[1][2])
      assert_equal({"message1" => "test5"}, events[2][2])
      assert_equal({"message1" => "test6", "message2" => "test7"}, events[3][2])
      assert_equal({"message1" => "test8"}, events[4][2])
    end

    data(
      flat: MULTILINE_CONFIG_WITH_NEWLINE,
      parse: PARSE_MULTILINE_CONFIG_WITH_NEWLINE)
    def test_multiline_with_emit_unmatched_lines2(data)
      config = data + config_element("", "", { "emit_unmatched_lines" => true })
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") { |f| }

      d = create_driver(config)
      d.run(expect_emits: 0, timeout: 1) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") { |f|
          f.puts "s test0"
          f.puts "f test1"
          f.puts "f test2"

          f.puts "f test3"

          f.puts "s test4"
          f.puts "f test5"
          f.puts "f test6"
        }
      end

      events = d.events
      assert_equal({"message1" => "test0", "message2" => "test1", "message3" => "test2"}, events[0][2])
      assert_equal({ 'unmatched_line' => "f test3" }, events[1][2])
      assert_equal({"message1" => "test4", "message2" => "test5", "message3" => "test6"}, events[2][2])
    end

    data(flat: MULTILINE_CONFIG,
         parse: PARSE_MULTILINE_CONFIG)
    def test_multiline_with_flush_interval(data)
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") { |f| }

      config = data + config_element("", "", { "multiline_flush_interval" => "2s" })
      d = create_driver(config)

      assert_equal(2, d.instance.multiline_flush_interval)

      d.run(expect_emits: 1) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") { |f|
          f.puts "f test1"
          f.puts "s test2"
          f.puts "f test3"
          f.puts "f test4"
          f.puts "s test5"
          f.puts "s test6"
          f.puts "f test7"
          f.puts "s test8"
        }
      end

      events = d.events
      assert_equal(4, events.length)
      assert_equal({"message1" => "test2", "message2" => "test3", "message3" => "test4"}, events[0][2])
      assert_equal({"message1" => "test5"}, events[1][2])
      assert_equal({"message1" => "test6", "message2" => "test7"}, events[2][2])
      assert_equal({"message1" => "test8"}, events[3][2])
    end

    data(
      'flat default encoding' => [MULTILINE_CONFIG, Encoding::ASCII_8BIT],
      'flat explicit encoding config' => [MULTILINE_CONFIG + config_element("", "", { "encoding" => "utf-8" }), Encoding::UTF_8],
      'parse default encoding' => [PARSE_MULTILINE_CONFIG, Encoding::ASCII_8BIT],
      'parse explicit encoding config' => [PARSE_MULTILINE_CONFIG + config_element("", "", { "encoding" => "utf-8" }), Encoding::UTF_8])
    def test_multiline_encoding_of_flushed_record(data)
      encoding_config, encoding = data

      config = config_element("", "", {
                                "multiline_flush_interval" => "2s",
                                "read_from_head" => "true",
                              })
      d = create_driver(config + encoding_config)

      d.run(expect_emits: 1) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") { |f|
          f.puts "s test"
        }
      end
      events = d.events
      assert_equal(1, events.length)
      assert_equal(encoding, events[0][2]['message1'].encoding)
    end

    def test_multiline_from_encoding_of_flushed_record
      conf = MULTILINE_CONFIG + config_element(
               "", "",
               {
                 "multiline_flush_interval" => "1s",
                 "read_from_head" => "true",
                 "from_encoding" => "cp932",
                 "encoding" => "utf-8"
               })
      d = create_driver(conf)

      cp932_message = "s \x82\xCD\x82\xEB\x81\x5B\x82\xED\x81\x5B\x82\xE9\x82\xC7".force_encoding(Encoding::CP932)
      utf8_message = "\x82\xCD\x82\xEB\x81\x5B\x82\xED\x81\x5B\x82\xE9\x82\xC7".encode(Encoding::UTF_8, Encoding::CP932)
      d.run(expect_emits: 1) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "w:cp932") { |f|
          f.puts cp932_message
        }
      end

      events = d.events
      assert_equal(1, events.length)
      assert_equal(utf8_message, events[0][2]['message1'])
      assert_equal(Encoding::UTF_8, events[0][2]['message1'].encoding)
    end

    data(flat: config_element(
           "", "", {
             "format" => "multiline",
             "format1" => "/^s (?<message1>[^\\n]+)\\n?/",
             "format2" => "/(f (?<message2>[^\\n]+)\\n?)?/",
             "format3" => "/(f (?<message3>.*))?/",
             "format_firstline" => "/^[s]/"
           }),
         parse: config_element(
           "", "", {},
           [config_element("parse", "", {
                             "@type" => "multiline",
                             "format1" => "/^s (?<message1>[^\\n]+)\\n?/",
                             "format2" => "/(f (?<message2>[^\\n]+)\\n?)?/",
                             "format3" => "/(f (?<message3>.*))?/",
                             "format_firstline" => "/^[s]/"
                           })
           ])
        )
    def test_multiline_with_multiple_formats(data)
      config = data
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") { |f| }

      d = create_driver(config)
      d.run(expect_emits: 1) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") { |f|
          f.puts "f test1"
          f.puts "s test2"
          f.puts "f test3"
          f.puts "f test4"
          f.puts "s test5"
          f.puts "s test6"
          f.puts "f test7"
          f.puts "s test8"
        }
      end

      events = d.events
      assert(events.length > 0)
      assert_equal({"message1" => "test2", "message2" => "test3", "message3" => "test4"}, events[0][2])
      assert_equal({"message1" => "test5"}, events[1][2])
      assert_equal({"message1" => "test6", "message2" => "test7"}, events[2][2])
      assert_equal({"message1" => "test8"}, events[3][2])
    end

    data(flat: config_element(
           "", "", {
             "format" => "multiline",
             "format1" => "/^[s|f] (?<message>.*)/",
             "format_firstline" => "/^[s]/"
           }),
         parse: config_element(
           "", "", {},
           [config_element("parse", "", {
                             "@type" => "multiline",
                             "format1" => "/^[s|f] (?<message>.*)/",
                             "format_firstline" => "/^[s]/"
                           })
           ])
        )
    def test_multilinelog_with_multiple_paths(data)
      files = ["#{@tmp_dir}/tail1.txt", "#{@tmp_dir}/tail2.txt"]
      files.each { |file| Fluent::FileWrapper.open(file, "wb") { |f| } }

      config = data + config_element("", "", {
                                       "path" => "#{files[0]},#{files[1]}",
                                       "tag" => "t1",
                                     })
      d = create_driver(config, false)
      d.run(expect_emits: 2) do
        files.each do |file|
          Fluent::FileWrapper.open(file, 'ab') { |f|
            f.puts "f #{file} line should be ignored"
            f.puts "s test1"
            f.puts "f test2"
            f.puts "f test3"
            f.puts "s test4"
          }
        end
      end

      events = d.events
      assert_equal({"message" => "test1\nf test2\nf test3"}, events[0][2])
      assert_equal({"message" => "test1\nf test2\nf test3"}, events[1][2])
      # "test4" events are here because these events are flushed at shutdown phase
      assert_equal({"message" => "test4"}, events[2][2])
      assert_equal({"message" => "test4"}, events[3][2])
    end

    data(flat: config_element("", "", {
                                "format" => "multiline",
                                "format1" => "/(?<var1>foo \\d)\\n/",
                                "format2" => "/(?<var2>bar \\d)\\n/",
                                "format3" => "/(?<var3>baz \\d)/"
                              }),
         parse: config_element(
           "", "", {},
           [config_element("parse", "", {
                             "@type" => "multiline",
                             "format1" => "/(?<var1>foo \\d)\\n/",
                             "format2" => "/(?<var2>bar \\d)\\n/",
                             "format3" => "/(?<var3>baz \\d)/"
                           })
           ])
        )
    def test_multiline_without_firstline(data)
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") { |f| }

      config = data
      d = create_driver(config)
      d.run(expect_emits: 1) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") { |f|
          f.puts "foo 1"
          f.puts "bar 1"
          f.puts "baz 1"
          f.puts "foo 2"
          f.puts "bar 2"
          f.puts "baz 2"
        }
      end

      events = d.events
      assert_equal(2, events.length)
      assert_equal({"var1" => "foo 1", "var2" => "bar 1", "var3" => "baz 1"}, events[0][2])
      assert_equal({"var1" => "foo 2", "var2" => "bar 2", "var3" => "baz 2"}, events[1][2])
    end
  end

  sub_test_case "path" do
    # * path test
    # TODO: Clean up tests
    def test_expand_paths
      ex_paths = [
        create_target_info('test/plugin/data/2010/01/20100102-030405.log'),
        create_target_info('test/plugin/data/log/foo/bar.log'),
        create_target_info('test/plugin/data/log/test.log')
      ]
      plugin = create_driver(ex_config, false).instance
      flexstub(Time) do |timeclass|
        timeclass.should_receive(:now).with_no_args.and_return(Time.new(2010, 1, 2, 3, 4, 5))
        assert_equal(ex_paths, plugin.expand_paths.values.sort_by { |path_ino| path_ino.path })
      end

      # Test exclusion
      exclude_config = ex_config + config_element("", "", { "exclude_path" => %Q(["#{ex_paths.last.path}"]) })
      plugin = create_driver(exclude_config, false).instance
      assert_equal(ex_paths - [ex_paths.last], plugin.expand_paths.values.sort_by { |path_ino| path_ino.path })
    end

    def test_expand_paths_with_duplicate_configuration
      expanded_paths = [
        create_target_info('test/plugin/data/log/foo/bar.log'),
        create_target_info('test/plugin/data/log/test.log')
      ]
      duplicate_config = ex_config.dup
      duplicate_config["path"]="test/plugin/data/log/**/*.log, test/plugin/data/log/**/*.log"
      plugin = create_driver(ex_config, false).instance
      assert_equal(expanded_paths, plugin.expand_paths.values.sort_by { |path_ino| path_ino.path })
    end

    def test_expand_paths_with_timezone
      ex_paths = [
        create_target_info('test/plugin/data/2010/01/20100102-030405.log'),
        create_target_info('test/plugin/data/log/foo/bar.log'),
        create_target_info('test/plugin/data/log/test.log')
      ]
      ['Asia/Taipei', '+08'].each do |tz_type|
        taipei_config = ex_config + config_element("", "", {"path_timezone" => tz_type})
        plugin = create_driver(taipei_config, false).instance

        # Test exclude
        exclude_config = taipei_config + config_element("", "", { "exclude_path" => %Q(["test/plugin/**/%Y%m%d-%H%M%S.log"]) })
        exclude_plugin = create_driver(exclude_config, false).instance

        with_timezone('utc') do
          flexstub(Time) do |timeclass|
            # env : 2010-01-01 19:04:05 (UTC), tail path : 2010-01-02 03:04:05 (Asia/Taipei)
            timeclass.should_receive(:now).with_no_args.and_return(Time.new(2010, 1, 1, 19, 4, 5))

            assert_equal(ex_paths, plugin.expand_paths.values.sort_by { |path_ino| path_ino.path })
            assert_equal(ex_paths - [ex_paths.first], exclude_plugin.expand_paths.values.sort_by { |path_ino| path_ino.path })
          end
        end
      end
    end

    def test_log_file_without_extension
      expected_files = [
        create_target_info('test/plugin/data/log/bar'),
        create_target_info('test/plugin/data/log/foo/bar.log'),
        create_target_info('test/plugin/data/log/foo/bar2'),
        create_target_info('test/plugin/data/log/test.log')
      ]

      config = config_element("", "", {
        "tag" => "tail",
        "path" => "test/plugin/data/log/**/*",
        "format" => "none",
        "pos_file" => "#{@tmp_dir}/tail.pos"
      })

      plugin = create_driver(config, false).instance
      assert_equal(expected_files, plugin.expand_paths.values.sort_by { |path_ino| path_ino.path })
    end

    def test_unwatched_files_should_be_removed
      config = config_element("", "", {
                                "tag" => "tail",
                                "path" => "#{@tmp_dir}/*.txt",
                                "format" => "none",
                                "pos_file" => "#{@tmp_dir}/tail.pos",
                                "read_from_head" => true,
                                "refresh_interval" => 1,
                              })
      d = create_driver(config, false)
      d.end_if { d.instance.instance_variable_get(:@tails).keys.size >= 1 }
      d.run(expect_emits: 1, shutdown: false) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") { |f| f.puts "test3\n" }
      end

      cleanup_file("#{@tmp_dir}/tail.txt")
      waiting(20) { sleep 0.1 until Dir.glob("#{@tmp_dir}/*.txt").size == 0 } # Ensure file is deleted on Windows
      waiting(5) { sleep 0.1 until d.instance.instance_variable_get(:@tails).keys.size <= 0 }

      assert_equal(
        {
          files: [],
          tails: []
        },
        {
          files: Dir.glob("#{@tmp_dir}/*.txt"),
          tails: d.instance.instance_variable_get(:@tails).keys
        }
      )
    ensure
      d.instance_shutdown if d && d.instance
      cleanup_directory(@tmp_dir)
    end

    def count_timer_object
      num = 0
      ObjectSpace.each_object(Fluent::PluginHelper::Timer::TimerWatcher) { |obj|
        num += 1
      }
      num
    end
  end

  sub_test_case "path w/ Linux capability" do
    def capability_enabled?
      if Fluent.linux?
        begin
          require 'capng'
          true
        rescue LoadError
          false
        end
      else
        false
      end
    end

    setup do
      omit "This environment is not enabled Linux capability handling feature" unless capability_enabled?

      @capng = CapNG.new(:current_process)
      flexstub(Fluent::Capability) do |klass|
        klass.should_receive(:new).with(:current_process).and_return(@capng)
      end
    end

    data("dac_read_search" => [:dac_read_search, true,  1],
         "dac_override"    => [:dac_override,    true,  1],
         "chown"           => [:chown,           false, 0],
        )
    test "with partially elevated privileges" do |data|
      cap, result, readable_paths = data
      @capng.update(:add, :effective, cap)

      d = create_driver(
        config_element("ROOT", "", {
                            "path" => "/var/log/ker*.log", # Use /var/log/kern.log
                            "tag" => "t1",
                            "rotate_wait" => "2s"
                       }) + PARSE_SINGLE_LINE_CONFIG, false)

      assert_equal(readable_paths, d.instance.expand_paths.length)
      assert_equal(result, d.instance.have_read_capability?)
    end
  end

  def test_pos_file_dir_creation
    config = config_element("", "", {
      "tag" => "tail",
      "path" => "#{@tmp_dir}/*.txt",
      "format" => "none",
      "pos_file" => "#{@tmp_dir}/pos/tail.pos",
      "read_from_head" => true,
      "refresh_interval" => 1
    })

    assert_path_not_exist("#{@tmp_dir}/pos")
    d = create_driver(config, false)
    d.run
    assert_path_exist("#{@tmp_dir}/pos")
    assert_equal('755', File.stat("#{@tmp_dir}/pos").mode.to_s(8)[-3, 3])
  ensure
    cleanup_directory(@tmp_dir)
  end

  def test_pos_file_dir_creation_with_system_dir_permission
    config = config_element("", "", {
      "tag" => "tail",
      "path" => "#{@tmp_dir}/*.txt",
      "format" => "none",
      "pos_file" => "#{@tmp_dir}/pos/tail.pos",
      "read_from_head" => true,
      "refresh_interval" => 1
    })

    assert_path_not_exist("#{@tmp_dir}/pos")

    Fluent::SystemConfig.overwrite_system_config({ "dir_permission" => "744" }) do
      d = create_driver(config, false)
      d.run
    end

    assert_path_exist("#{@tmp_dir}/pos")
    if Fluent.windows?
      assert_equal('755', File.stat("#{@tmp_dir}/pos").mode.to_s(8)[-3, 3])
    else
      assert_equal('744', File.stat("#{@tmp_dir}/pos").mode.to_s(8)[-3, 3])
    end
  ensure
    cleanup_directory(@tmp_dir)
  end

  def test_z_refresh_watchers
    ex_paths = [
      create_target_info('test/plugin/data/2010/01/20100102-030405.log'),
      create_target_info('test/plugin/data/log/foo/bar.log'),
      create_target_info('test/plugin/data/log/test.log'),
    ]
    plugin = create_driver(ex_config, false).instance
    sio = StringIO.new
    plugin.instance_eval do
      @pf = Fluent::Plugin::TailInput::PositionFile.load(sio, EX_FOLLOW_INODES, {}, logger: $log)
      @loop = Coolio::Loop.new
      opened_file_metrics = Fluent::Plugin::LocalMetrics.new
      opened_file_metrics.configure(config_element('metrics', '', {}))
      closed_file_metrics = Fluent::Plugin::LocalMetrics.new
      closed_file_metrics.configure(config_element('metrics', '', {}))
      rotated_file_metrics = Fluent::Plugin::LocalMetrics.new
      rotated_file_metrics.configure(config_element('metrics', '', {}))
      @metrics = Fluent::Plugin::TailInput::MetricsInfo.new(opened_file_metrics, closed_file_metrics, rotated_file_metrics)
    end

    Timecop.freeze(2010, 1, 2, 3, 4, 5) do
      ex_paths.each do |target_info|
        mock.proxy(Fluent::Plugin::TailInput::TailWatcher).new(target_info, anything, anything, true, false, anything, nil, anything, anything).once
      end

      plugin.refresh_watchers
    end

    path = 'test/plugin/data/2010/01/20100102-030405.log'
    mock.proxy(plugin).detach_watcher_after_rotate_wait(plugin.instance_variable_get(:@tails)[path], Fluent::FileWrapper.stat(path).ino)

    Timecop.freeze(2010, 1, 2, 3, 4, 6) do
      path = "test/plugin/data/2010/01/20100102-030406.log"
      inode = Fluent::FileWrapper.stat(path).ino
      target_info = Fluent::Plugin::TailInput::TargetInfo.new(path, inode)
      mock.proxy(Fluent::Plugin::TailInput::TailWatcher).new(target_info, anything, anything, true, false, anything, nil, anything, anything).once
      plugin.refresh_watchers

      flexstub(Fluent::Plugin::TailInput::TailWatcher) do |watcherclass|
        watcherclass.should_receive(:new).never
        plugin.refresh_watchers
      end
    end
  end

  sub_test_case "refresh of pos file" do
    test 'type of pos_file_compaction_interval is time' do
      tail = {
        "tag" => "tail",
        "path" => "#{@tmp_dir}/*.txt",
        "format" => "none",
        "pos_file" => "#{@tmp_dir}/pos/tail.pos",
        "refresh_interval" => 1,
        "read_from_head" => true,
        'pos_file_compaction_interval' => '24h',
      }
      config = config_element("", "", tail)
      d = create_driver(config, false)
      mock(d.instance).timer_execute(:in_tail_refresh_watchers, 1.0).once
      mock(d.instance).timer_execute(:in_tail_refresh_compact_pos_file, 60 * 60 * 24).once
      d.run                     # call start
    end
  end

  sub_test_case "receive_lines" do
    DummyWatcher = Struct.new("DummyWatcher", :tag)

    def test_tag
      d = create_driver(ex_config, false)
      d.run {}
      plugin = d.instance
      mock(plugin.router).emit_stream('tail', anything).once
      plugin.receive_lines(['foo', 'bar'], DummyWatcher.new('foo.bar.log'))
    end

    def test_tag_with_only_star
      config = config_element("", "", {
                                "tag" => "*",
                                "path" => "test/plugin/*/%Y/%m/%Y%m%d-%H%M%S.log,test/plugin/data/log/**/*.log",
                                "format" => "none",
                                "read_from_head" => true
                              })
      d = create_driver(config, false)
      d.run {}
      plugin = d.instance
      mock(plugin.router).emit_stream('foo.bar.log', anything).once
      plugin.receive_lines(['foo', 'bar'], DummyWatcher.new('foo.bar.log'))
    end

    def test_tag_prefix
      config = config_element("", "", {
                                "tag" => "pre.*",
                                "path" => "test/plugin/*/%Y/%m/%Y%m%d-%H%M%S.log,test/plugin/data/log/**/*.log",
                                "format" => "none",
                                "read_from_head" => true
                              })
      d = create_driver(config, false)
      d.run {}
      plugin = d.instance
      mock(plugin.router).emit_stream('pre.foo.bar.log', anything).once
      plugin.receive_lines(['foo', 'bar'], DummyWatcher.new('foo.bar.log'))
    end

    def test_tag_suffix
      config = config_element("", "", {
                                "tag" => "*.post",
                                "path" => "test/plugin/*/%Y/%m/%Y%m%d-%H%M%S.log,test/plugin/data/log/**/*.log",
                                "format" => "none",
                                "read_from_head" => true
                              })
      d = create_driver(config, false)
      d.run {}
      plugin = d.instance
      mock(plugin.router).emit_stream('foo.bar.log.post', anything).once
      plugin.receive_lines(['foo', 'bar'], DummyWatcher.new('foo.bar.log'))
    end

    def test_tag_prefix_and_suffix
      config = config_element("", "", {
                                "tag" => "pre.*.post",
                                "path" => "test/plugin/*/%Y/%m/%Y%m%d-%H%M%S.log,test/plugin/data/log/**/*.log",
                                "format" => "none",
                                "read_from_head" => true
                              })
      d = create_driver(config, false)
      d.run {}
      plugin = d.instance
      mock(plugin.router).emit_stream('pre.foo.bar.log.post', anything).once
      plugin.receive_lines(['foo', 'bar'], DummyWatcher.new('foo.bar.log'))
    end

    def test_tag_prefix_and_suffix_ignore
      config = config_element("", "", {
                                "tag" => "pre.*.post*ignore",
                                "path" => "test/plugin/*/%Y/%m/%Y%m%d-%H%M%S.log,test/plugin/data/log/**/*.log",
                                "format" => "none",
                                "read_from_head" => true
                              })
      d = create_driver(config, false)
      d.run {}
      plugin = d.instance
      mock(plugin.router).emit_stream('pre.foo.bar.log.post', anything).once
      plugin.receive_lines(['foo', 'bar'], DummyWatcher.new('foo.bar.log'))
    end

    data(
      small: ["128", 128],
      KiB: ["1k", 1024]
    )
    test 'max_line_size' do |(label, size)|
      config = config_element("", "", {
                                "tag" => "max_line_size",
                                "path" => "#{@tmp_dir}/with_long_lines.txt",
                                "format" => "none",
                                "read_from_head" => true,
                                "max_line_size" => label,
                                "log_level" => "debug"
                              })
      Fluent::FileWrapper.open("#{@tmp_dir}/with_long_lines.txt", "w+") do |f|
        f.puts "foo"
        f.puts "x" * size # 'x' * size + \n > @max_line_size
        f.puts "bar"
      end
      d = create_driver(config, false)
      timestamp = Time.parse("Mon Nov 29 11:22:33 UTC 2021")
      Timecop.freeze(timestamp)
      d.run(expect_records: 2)
      assert_equal([
                     [{"message" => "foo"},{"message" => "bar"}],
                     [
                       "2021-11-29 11:22:33 +0000 [warn]: received line length is longer than #{size}\n",
                       "2021-11-29 11:22:33 +0000 [debug]: skipped line: #{'x' * size}\n"
                     ]
                   ],
                   [
                     d.events.collect { |event| event.last },
                     d.logs[-2..]
                   ])
    end
  end

  # Ensure that no fatal exception is raised when a file is missing and that
  # files that do exist are still tailed as expected.
  def test_missing_file
    Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f|
      f.puts "test1"
      f.puts "test2"
    }

    # Try two different configs - one with read_from_head and one without,
    # since their interactions with the filesystem differ.
    config1 = config_element("", "", {
                               "tag" => "t1",
                               "path" => "#{@tmp_dir}/non_existent_file.txt,#{@tmp_dir}/tail.txt",
                               "format" => "none",
                               "rotate_wait" => "2s",
                               "pos_file" => "#{@tmp_dir}/tail.pos"
                             })
    config2 = config1 + config_element("", "", { "read_from_head" => true })
    [config1, config2].each do |config|
      d = create_driver(config, false)
      d.run(expect_emits: 1) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f|
          f.puts "test3"
          f.puts "test4"
        }
      end
      # This test sometimes fails and it shows a potential bug of in_tail
      # https://github.com/fluent/fluentd/issues/1434
      events = d.events
      assert_equal(2, events.length)
      assert_equal({"message" => "test3"}, events[0][2])
      assert_equal({"message" => "test4"}, events[1][2])
    end
  end

  sub_test_case 'inode_processing' do
    def test_should_delete_file_pos_entry_for_non_existing_file_with_follow_inodes
      config = common_follow_inode_config

      path = "#{@tmp_dir}/tail.txt"
      ino = 1
      pos = 1234
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.pos", "wb") {|f|
        f.puts ("%s\t%016x\t%016x\n" % [path, pos, ino])
      }

      d = create_driver(config, false)
      d.run

      pos_file = Fluent::FileWrapper.open("#{@tmp_dir}/tail.pos", "r")
      pos_file.pos = 0

      assert_raise(EOFError) do
        pos_file.readline
      end
    end

    def test_should_write_latest_offset_after_rotate_wait
      config = common_follow_inode_config
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f|
        f.puts "test1"
        f.puts "test2"
      }

      d = create_driver(config, false)
      d.run(expect_emits: 2, shutdown: false) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f| f.puts "test3\n"}
        FileUtils.move("#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail.txt" + "1")
        sleep 1
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt" + "1", "ab") {|f| f.puts "test4\n"}
      end

      pos_file = Fluent::FileWrapper.open("#{@tmp_dir}/tail.pos", "r")
      pos_file.pos = 0
      line_parts = /^([^\t]+)\t([0-9a-fA-F]+)\t([0-9a-fA-F]+)/.match(pos_file.readline)
      waiting(5) {
        while line_parts[2].to_i(16) != 24
          sleep(0.1)
          pos_file.pos = 0
          line_parts = /^([^\t]+)\t([0-9a-fA-F]+)\t([0-9a-fA-F]+)/.match(pos_file.readline)
        end
      }
      assert_equal(24, line_parts[2].to_i(16))
      d.instance_shutdown
    end

    def test_should_remove_deleted_file
      config = config_element("", "", {"format" => "none"})

      path = "#{@tmp_dir}/tail.txt"
      ino = 1
      pos = 1234
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.pos", "wb") {|f|
        f.puts ("%s\t%016x\t%016x\n" % [path, pos, ino])
      }

      d = create_driver(config)
      d.run do
        pos_file = Fluent::FileWrapper.open("#{@tmp_dir}/tail.pos", "r")
        pos_file.pos = 0
        assert_equal([], pos_file.readlines)
      end
    end

    def test_should_mark_file_unwatched_after_limit_recently_modified_and_rotate_wait
      config = config_element("ROOT", "", {
          "path" => "#{@tmp_dir}/tail.txt*",
          "pos_file" => "#{@tmp_dir}/tail.pos",
          "tag" => "t1",
          "rotate_wait" => "1s",
          "refresh_interval" => "1s",
          "limit_recently_modified" => "1s",
          "read_from_head" => "true",
          "format" => "none",
          "follow_inodes" => "true",
      })

      d = create_driver(config, false)

      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f|
        f.puts "test1"
        f.puts "test2"
      }
      target_info = create_target_info("#{@tmp_dir}/tail.txt")

      d.run(expect_emits: 1, shutdown: false) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f| f.puts "test3\n"}
      end


      Timecop.travel(Time.now + 10) do
        waiting(5) {
          # @pos will be reset as 0 when UNWATCHED_POSITION is specified.
          sleep 0.1 until d.instance.instance_variable_get(:@pf)[target_info].read_pos == 0
        }
      end

      assert_equal(0, d.instance.instance_variable_get(:@pf)[target_info].read_pos)

      d.instance_shutdown
    end

    def test_should_read_from_head_on_file_renaming_with_star_in_pattern
      config = config_element("ROOT", "", {
          "path" => "#{@tmp_dir}/tail.txt*",
          "pos_file" => "#{@tmp_dir}/tail.pos",
          "tag" => "t1",
          "rotate_wait" => "10s",
          "refresh_interval" => "1s",
          "limit_recently_modified" => "60s",
          "read_from_head" => "true",
          "format" => "none",
          "follow_inodes" => "true"
      })

      d = create_driver(config, false)

      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f|
        f.puts "test1"
        f.puts "test2"
      }

      d.run(expect_emits: 2, shutdown: false) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f| f.puts "test3\n"}
        FileUtils.move("#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail.txt1")
      end

      events = d.events
      assert_equal(3, events.length)
      d.instance_shutdown
    end

    def test_should_not_read_from_head_on_rotation_when_watching_inodes
      config = common_follow_inode_config

      d = create_driver(config, false)

      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f|
        f.puts "test1"
        f.puts "test2"
      }

      d.run(expect_emits: 1, shutdown: false) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f| f.puts "test3\n"}
      end

      FileUtils.move("#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail.txt1")
      Timecop.travel(Time.now + 10) do
        sleep 2
        events = d.events
        assert_equal(3, events.length)
      end

      d.instance_shutdown
    end

    def test_should_mark_file_unwatched_if_same_name_file_created_with_different_inode
      config = common_follow_inode_config

      d = create_driver(config, false)

      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f|
        f.puts "test1"
        f.puts "test2"
      }
      target_info = create_target_info("#{@tmp_dir}/tail.txt")

      d.run(expect_emits: 2, shutdown: false) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f| f.puts "test3\n"}
        cleanup_file("#{@tmp_dir}/tail.txt")
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f| f.puts "test4\n"}
      end

      new_target_info = create_target_info("#{@tmp_dir}/tail.txt")

      pos_file = d.instance.instance_variable_get(:@pf)

      waiting(10) {
        # @pos will be reset as 0 when UNWATCHED_POSITION is specified.
        sleep 0.1 until pos_file[target_info].read_pos == 0
      }
      new_position = pos_file[new_target_info].read_pos
      assert_equal(6, new_position)

      d.instance_shutdown
    end

    def test_should_close_watcher_after_rotate_wait
      now = Time.now
      config = common_follow_inode_config + config_element('', '', {"rotate_wait" => "1s", "limit_recently_modified" => "1s"})

      d = create_driver(config, false)
      d.instance.instance_eval do
        opened_file_metrics = Fluent::Plugin::LocalMetrics.new
        opened_file_metrics.configure(config_element('metrics', '', {}))
        closed_file_metrics = Fluent::Plugin::LocalMetrics.new
        closed_file_metrics.configure(config_element('metrics', '', {}))
        rotated_file_metrics = Fluent::Plugin::LocalMetrics.new
        rotated_file_metrics.configure(config_element('metrics', '', {}))
        @metrics = Fluent::Plugin::TailInput::MetricsInfo.new(opened_file_metrics, closed_file_metrics, rotated_file_metrics)
      end

      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f|
        f.puts "test1"
        f.puts "test2"
      }
      target_info = create_target_info("#{@tmp_dir}/tail.txt")
      mock.proxy(Fluent::Plugin::TailInput::TailWatcher).new(target_info, anything, anything, true, true, anything, nil, anything, anything).once
      d.run(shutdown: false)
      assert d.instance.instance_variable_get(:@tails)[target_info.path]

      Timecop.travel(now + 10) do
        d.instance.instance_eval do
          sleep 0.1 until @tails[target_info.path] == nil
        end
        assert_nil d.instance.instance_variable_get(:@tails)[target_info.path]
      end
      d.instance_shutdown
    end

    def test_should_create_new_watcher_for_new_file_with_same_name
      now = Time.now
      config = common_follow_inode_config + config_element('', '', {"limit_recently_modified" => "2s"})

      d = create_driver(config, false)

      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f|
        f.puts "test1"
        f.puts "test2"
      }
      path_ino = create_target_info("#{@tmp_dir}/tail.txt")

      d.run(expect_emits: 1, shutdown: false) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f| f.puts "test3\n"}
      end

      cleanup_file("#{@tmp_dir}/tail.txt")
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f|
        f.puts "test3"
        f.puts "test4"
      }
      new_path_ino = create_target_info("#{@tmp_dir}/tail.txt")

      Timecop.travel(now + 10) do
        sleep 3
        d.instance.instance_eval do
          @tails[path_ino.path] == nil
          @tails[new_path_ino.path] != nil
        end
      end

      events = d.events

      assert_equal(5, events.length)

      d.instance_shutdown
    end

    def test_truncate_file_with_follow_inodes
      config = common_follow_inode_config

      d = create_driver(config, false)

      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f|
        f.puts "test1"
        f.puts "test2"
      }

      d.run(expect_emits: 3, shutdown: false) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f| f.puts "test3\n"}
        sleep 2
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "w+b") {|f| f.puts "test4\n"}
      end

      events = d.events
      assert_equal(4, events.length)
      assert_equal({"message" => "test1"}, events[0][2])
      assert_equal({"message" => "test2"}, events[1][2])
      assert_equal({"message" => "test3"}, events[2][2])
      assert_equal({"message" => "test4"}, events[3][2])
      d.instance_shutdown
    end

    # issue #3464
    def test_should_replace_target_info
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f|
        f.puts "test1\n"
      }
      target_info = create_target_info("#{@tmp_dir}/tail.txt")
      inodes = []

      config = config_element("ROOT", "", {
                                "path" => "#{@tmp_dir}/tail.txt*",
                                "pos_file" => "#{@tmp_dir}/tail.pos",
                                "tag" => "t1",
                                "refresh_interval" => "60s",
                                "read_from_head" => "true",
                                "format" => "none",
                                "rotate_wait" => "1s",
                                "follow_inodes" => "true"
                              })
      d = create_driver(config, false)
      d.run(timeout: 5) do
        while d.events.size < 1 do
          sleep 0.1
        end
        inodes = d.instance.instance_variable_get(:@tails).values.collect do |tw|
          tw.ino
        end
        assert_equal([target_info.ino], inodes)

        cleanup_file("#{@tmp_dir}/tail.txt")
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f| f.puts "test2\n"}

        while d.events.size < 2 do
          sleep 0.1
        end
        inodes = d.instance.instance_variable_get(:@tails).values.collect do |tw|
          tw.ino
        end
        new_target_info = create_target_info("#{@tmp_dir}/tail.txt")
        assert_not_equal(target_info.ino, new_target_info.ino)
        assert_equal([new_target_info.ino], inodes)
      end
    end
  end

  sub_test_case "tail_path" do
    def test_tail_path_with_singleline
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f|
        f.puts "test1"
        f.puts "test2"
      }

      d = create_driver(SINGLE_LINE_CONFIG + config_element("", "", { "path_key" => "path" }))

      d.run(expect_emits: 1) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f|
          f.puts "test3"
          f.puts "test4"
        }
      end

      events = d.events
      assert_equal(true, events.length > 0)
      events.each do |emit|
        assert_equal("#{@tmp_dir}/tail.txt", emit[2]["path"])
      end
    end

    def test_tail_path_with_multiline_with_firstline
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") { |f| }

      config = config_element("", "", {
                                "path_key" => "path",
                                "format" => "multiline",
                                "format1" => "/^s (?<message1>[^\\n]+)(\\nf (?<message2>[^\\n]+))?(\\nf (?<message3>.*))?/",
                                "format_firstline" => "/^[s]/"
                              })
      d = create_driver(config)
      d.run(expect_emits: 1) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") { |f|
          f.puts "f test1"
          f.puts "s test2"
          f.puts "f test3"
          f.puts "f test4"
          f.puts "s test5"
          f.puts "s test6"
          f.puts "f test7"
          f.puts "s test8"
        }
      end

      events = d.events
      assert_equal(4, events.length)
      events.each do |emit|
        assert_equal("#{@tmp_dir}/tail.txt", emit[2]["path"])
      end
    end

    def test_tail_path_with_multiline_without_firstline
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") { |f| }

      config = config_element("", "", {
                                "path_key" => "path",
                                "format" => "multiline",
                                "format1" => "/(?<var1>foo \\d)\\n/",
                                "format2" => "/(?<var2>bar \\d)\\n/",
                                "format3" => "/(?<var3>baz \\d)/",
                              })
      d = create_driver(config)
      d.run(expect_emits: 1) do
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") { |f|
          f.puts "foo 1"
          f.puts "bar 1"
          f.puts "baz 1"
        }
      end

      events = d.events
      assert(events.length > 0)
      events.each do |emit|
        assert_equal("#{@tmp_dir}/tail.txt", emit[2]["path"])
      end
    end

    def test_tail_path_with_multiline_with_multiple_paths
      if ENV["APPVEYOR"] && Fluent.windows?
        omit "This testcase is unstable on AppVeyor."
      end
      files = ["#{@tmp_dir}/tail1.txt", "#{@tmp_dir}/tail2.txt"]
      files.each { |file| Fluent::FileWrapper.open(file, "wb") { |f| } }

      config = config_element("", "", {
                                "path" => "#{files[0]},#{files[1]}",
                                "path_key" => "path",
                                "tag" => "t1",
                                "format" => "multiline",
                                "format1" => "/^[s|f] (?<message>.*)/",
                                "format_firstline" => "/^[s]/"
                              })
      d = create_driver(config, false)
      d.run(expect_emits: 2) do
        files.each do |file|
          Fluent::FileWrapper.open(file, 'ab') { |f|
            f.puts "f #{file} line should be ignored"
            f.puts "s test1"
            f.puts "f test2"
            f.puts "f test3"
            f.puts "s test4"
          }
        end
      end

      events = d.events
      assert_equal(4, events.length)
      assert_equal(files, [events[0][2]["path"], events[1][2]["path"]].sort)
      # "test4" events are here because these events are flushed at shutdown phase
      assert_equal(files, [events[2][2]["path"], events[3][2]["path"]].sort)
    end
  end

  def test_limit_recently_modified
    now = Time.new(2010, 1, 2, 3, 4, 5)
    FileUtils.touch("#{@tmp_dir}/tail_unwatch.txt", mtime: (now - 3601))
    FileUtils.touch("#{@tmp_dir}/tail_watch1.txt", mtime: (now - 3600))
    FileUtils.touch("#{@tmp_dir}/tail_watch2.txt", mtime: now)

    config = config_element('', '', {
      'tag' => 'tail',
      'path' => "#{@tmp_dir}/*.txt",
      'format' => 'none',
      'limit_recently_modified' => '3600s'
    })

    expected_files = [
      create_target_info("#{@tmp_dir}/tail_watch1.txt"),
      create_target_info("#{@tmp_dir}/tail_watch2.txt")
    ]

    Timecop.freeze(now) do
      plugin = create_driver(config, false).instance
      assert_equal(expected_files, plugin.expand_paths.values.sort_by { |path_ino| path_ino.path })
    end
  end

  def test_skip_refresh_on_startup
    FileUtils.touch("#{@tmp_dir}/tail.txt")
    config = config_element('', '', {
                              'format' => 'none',
                              'refresh_interval' => 1,
                              'skip_refresh_on_startup' => true
                            })
    d = create_driver(config)
    d.run(shutdown: false) {}
    assert_equal(0, d.instance.instance_variable_get(:@tails).keys.size)
    # detect a file at first execution of in_tail_refresh_watchers timer
    waiting(5) { sleep 0.1 until d.instance.instance_variable_get(:@tails).keys.size == 1 }
    d.instance_shutdown
  end

  def test_ENOENT_error_after_setup_watcher
    path = "#{@tmp_dir}/tail.txt"
    FileUtils.touch(path)
    config = config_element('', '', {
                              'format' => 'none',
                            })
    d = create_driver(config)
    file_deleted = false
    mock.proxy(d.instance).existence_path do |hash|
      unless file_deleted
        cleanup_file(path)
        file_deleted = true
      end
      hash
    end.twice
    assert_nothing_raised do
      d.run(shutdown: false) {}
    end
    assert($log.out.logs.any?{|log| log.include?("stat() for #{path} failed. Continuing without tailing it.\n") },
           $log.out.logs.join("\n"))
  ensure
    d.instance_shutdown if d && d.instance
  end

  def test_EACCES_error_after_setup_watcher
    omit "Cannot test with root user" if Process::UID.eid == 0
    path = "#{@tmp_dir}/noaccess/tail.txt"
    begin
      FileUtils.mkdir_p("#{@tmp_dir}/noaccess")
      FileUtils.chmod(0755, "#{@tmp_dir}/noaccess")
      FileUtils.touch(path)
      config = config_element('', '', {
                                'tag' => "tail",
                                'path' => path,
                                'format' => 'none',
                              })
      d = create_driver(config, false)
      mock.proxy(d.instance).existence_path do |hash|
        FileUtils.chmod(0000, "#{@tmp_dir}/noaccess")
        hash
      end.twice
      assert_nothing_raised do
        d.run(shutdown: false) {}
      end
      assert($log.out.logs.any?{|log| log.include?("stat() for #{path} failed. Continuing without tailing it.\n") },
             $log.out.logs.join("\n"))
    end
  ensure
    d.instance_shutdown if d && d.instance
    if File.exist?("#{@tmp_dir}/noaccess")
      FileUtils.chmod(0755, "#{@tmp_dir}/noaccess")
      FileUtils.rm_rf("#{@tmp_dir}/noaccess")
    end
  end unless Fluent.windows?

  def test_EACCES
    path = "#{@tmp_dir}/tail.txt"
    FileUtils.touch(path)
    config = config_element('', '', {
                              'format' => 'none',
                            })
    d = create_driver(config)
    mock.proxy(Fluent::FileWrapper).stat(path) do |stat|
      raise Errno::EACCES
    end.at_least(1)
    assert_nothing_raised do
      d.run(shutdown: false) {}
    end
    assert($log.out.logs.any?{|log| log.include?("expand_paths: stat() for #{path} failed with Errno::EACCES. Skip file.\n") })
  ensure
    d.instance_shutdown if d && d.instance
  end

  def test_shutdown_timeout
    Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") do |f|
      # Should be large enough to take too long time to consume
      (1024 * 1024 * 5).times do
        f.puts "{\"test\":\"fizzbuzz\"}"
      end
    end

    config =
      CONFIG_READ_FROM_HEAD +
      config_element('', '', {
                              'format' => 'json',
                              'skip_refresh_on_startup' => true,
                            })
    shutdown_start_time = 0

    d = create_driver(config)
    mock.proxy(d.instance).io_handler(anything, anything) do |io_handler|
      mock.proxy(io_handler).ready_to_shutdown(anything) do
        shutdown_start_time = Fluent::Clock.now
      end
      io_handler.shutdown_timeout = 0.5
      io_handler
    end

    assert_nothing_raised do
      d.run(expect_emits: 1)
    end

    elapsed = Fluent::Clock.now - shutdown_start_time
    assert_true(elapsed > 0.5 && elapsed < 2.0,
                "elapsed time: #{elapsed}")
  end

  sub_test_case "throttling logs at in_tail level" do
    data("file test1.log no_limit 5120 text: msg" => ["test1.log", 5120, "msg"],
         "file test2.log no_limit 1024 text: test" => ["test2.log", 1024, "test"])
    def test_lines_collected_with_no_throttling(data)
      file, num_lines, msg = data

      pattern = "/^#{@tmp_dir}\/(?<file>.+)\.log$/"
      rule = create_rule_directive({
        "file" => "/test.*/",
      }, -1)
      group = create_group_directive(pattern, "1s", rule)
      path_element = create_path_element(file)

      conf = ROOT_CONFIG + group + path_element + CONFIG_READ_FROM_HEAD + SINGLE_LINE_CONFIG

      Fluent::FileWrapper.open("#{@tmp_dir}/#{file}", 'wb') do |f|
        num_lines.times do
          f.puts "#{msg}\n"
        end
      end


      d = create_driver(conf, false)
      d.run(timeout: 3) do
        start_time = Fluent::Clock.now

        assert_equal(num_lines, d.record_count)
        assert_equal({ "message" => msg }, d.events[0][2])

        prev_count = d.record_count
        sleep(0.1) while d.emit_count < 1
        assert_true(Fluent::Clock.now - start_time < 2)
        ## after waiting for 1 (+ jitter) secs, limit will reset
        ## Plugin will start reading but it will encounter EOF Error
        ## since no logs are left to be read
        ## Hence, d.record_count = prev_count
        tail_watcher_interval = 1.0 # hard coded value in in_tail
        safety_ratio = 1.2
        jitter = tail_watcher_interval * safety_ratio
        sleep(1.0 + jitter)
        assert_equal(0, d.record_count - prev_count)
      end
    end

    test "lines collected with throttling" do
      file = "podname1_namespace12_container-123456.log"
      limit = 1000
      rate_period = 2
      num_lines = 3000
      msg = "a" * 8190 # Total size = 8190 bytes + 2 (\n) bytes

      rule = create_rule_directive({
        "namespace"=> "/namespace.+/",
        "podname"=> "/podname.+/",
      }, limit)
      path_element = create_path_element(file)
      conf = ROOT_CONFIG + create_group_directive(tailing_group_pattern, "#{rate_period}s", rule) + path_element + SINGLE_LINE_CONFIG + CONFIG_READ_FROM_HEAD

      d = create_driver(conf, false)
      file_path = "#{@tmp_dir}/#{file}"

      Fluent::FileWrapper.open(file_path, 'wb') do |f|
        num_lines.times do
          f.puts msg
        end
      end

      d.run(timeout: 15) do
        sleep_interval = 0.1
        tail_watcher_interval = 1.0 # hard coded value in in_tail
        safety_ratio = 1.2
        lower_jitter = sleep_interval * safety_ratio
        upper_jitter = (tail_watcher_interval + sleep_interval) * safety_ratio
        lower_interval = rate_period - lower_jitter
        upper_interval = rate_period + upper_jitter

        emit_count = 0
        prev_count = 0

        while emit_count < 3 do
          start_time = Fluent::Clock.now
          sleep(sleep_interval) while d.emit_count <= emit_count
          elapsed_seconds = Fluent::Clock.now - start_time
          if emit_count > 0
            assert_true(elapsed_seconds > lower_interval && elapsed_seconds < upper_interval,
                        "elapsed_seconds #{elapsed_seconds} is out of allowed range:\n" +
                        "  lower: #{lower_interval} [sec]\n" +
                        "  upper: #{upper_interval} [sec]")
          end
          assert_equal(limit, d.record_count - prev_count)
          emit_count = d.emit_count
          prev_count = d.record_count
        end

        ## When all the lines are read and rate_period seconds are over
        ## limit will reset and since there are no more logs to be read,
        ## number_lines_read will be 0
        sleep upper_interval
        gw = d.instance.find_group_from_metadata(file_path)
        assert_equal(0, gw.current_paths[file_path].number_lines_read)
      end
    end
  end

  sub_test_case "Update watchers for rotation with follow_inodes" do
    def test_updateTW_before_refreshTW_and_detach_before_refreshTW
      config = config_element(
        "ROOT",
        "",
        {
          "path" => "#{@tmp_dir}/tail.txt*",
          "pos_file" => "#{@tmp_dir}/tail.pos",
          "tag" => "t1",
          "format" => "none",
          "read_from_head" => "true",
          "follow_inodes" => "true",
          # In order to detach the old watcher quickly.
          "rotate_wait" => "1s",
          # In order to reproduce the same condition stably, ensure that `refresh_watchers` is not
          # called by a timer.
          "refresh_interval" => "1h",
          # stat_watcher often calls `TailWatcher::on_notify` faster than creating a new log file,
          # so disable it in order to reproduce the same condition stably.
          "enable_stat_watcher" => "false",
        }
      )
      d = create_driver(config, false)

      tail_watchers = []
      stub.proxy(d.instance).setup_watcher do |tw|
        tail_watchers.append(tw)
        tw
      end

      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f| f.puts "file1 log1"}

      d.run(expect_records: 4, timeout: 10) do
        # Rotate (If the timing is bad, `TailWatcher::on_notify` might be called between mv and new-file-creation)
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f| f.puts "file1 log2"}
        FileUtils.move("#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail.txt" + "1")
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f| f.puts "file2 log1"}

        # `watch_timer` calls `TailWatcher::on_notify`, and then `update_watcher` updates the TailWatcher:
        #     TailWatcher(path: "tail.txt", inode: inode_0) => TailWatcher(path: "tail.txt", inode: inode_1)
        # The old TailWathcer is detached here since `rotate_wait` is just `1s`.
        sleep 3

        # This reproduces the following situation:
        #     Rotation => update_watcher => refresh_watchers
        # This adds a new TailWatcher: TailWatcher(path: "tail.txt1", inode: inode_0)
        d.instance.refresh_watchers

        # Append to the new current log file.
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f| f.puts "file2 log2"}
      end

      inode_0 = tail_watchers[0].ino
      inode_1 = tail_watchers[1].ino
      record_values = d.events.collect { |event| event[2]["message"] }.sort
      position_entries = []
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.pos", "r") do |f|
        f.readlines(chomp: true).each do |line|
          values = line.split("\t")
          position_entries.append([values[0], values[1], values[2].to_i(16)])
        end
      end

      assert_equal(
        {
          record_values: ["file1 log1", "file1 log2", "file2 log1", "file2 log2"],
          tail_watcher_paths: ["#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail.txt1"],
          tail_watcher_inodes: [inode_0, inode_1, inode_0],
          tail_watcher_io_handler_opened_statuses: [false, false, false],
          position_entries: [
            ["#{@tmp_dir}/tail.txt", "0000000000000016", inode_0],
            ["#{@tmp_dir}/tail.txt", "0000000000000016", inode_1],
          ],
        },
        {
          record_values: record_values,
          tail_watcher_paths: tail_watchers.collect { |tw| tw.path },
          tail_watcher_inodes: tail_watchers.collect { |tw| tw.ino },
          tail_watcher_io_handler_opened_statuses: tail_watchers.collect { |tw| tw.instance_variable_get(:@io_handler)&.opened? || false },
          position_entries: position_entries
        },
      )
    end

    def test_updateTW_before_refreshTW_and_detach_after_refreshTW
      config = config_element(
        "ROOT",
        "",
        {
          "path" => "#{@tmp_dir}/tail.txt*",
          "pos_file" => "#{@tmp_dir}/tail.pos",
          "tag" => "t1",
          "format" => "none",
          "read_from_head" => "true",
          "follow_inodes" => "true",
          # In order to detach the old watcher after refresh_watchers.
          "rotate_wait" => "4s",
          # In order to reproduce the same condition stably, ensure that `refresh_watchers` is not
          # called by a timer.
          "refresh_interval" => "1h",
          # stat_watcher often calls `TailWatcher::on_notify` faster than creating a new log file,
          # so disable it in order to reproduce the same condition stably.
          "enable_stat_watcher" => "false",
        }
      )
      d = create_driver(config, false)

      tail_watchers = []
      stub.proxy(d.instance).setup_watcher do |tw|
        tail_watchers.append(tw)
        tw
      end

      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f| f.puts "file1 log1"}

      d.run(expect_records: 4, timeout: 10) do
        # Rotate (If the timing is bad, `TailWatcher::on_notify` might be called between mv and new-file-creation)
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f| f.puts "file1 log2"}
        FileUtils.move("#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail.txt" + "1")
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f| f.puts "file2 log1"}

        # `watch_timer` calls `TailWatcher::on_notify`, and then `update_watcher` updates the TailWatcher:
        #     TailWatcher(path: "tail.txt", inode: inode_0) => TailWatcher(path: "tail.txt", inode: inode_1)
        sleep 2

        # This reproduces the following situation:
        #     Rotation => update_watcher => refresh_watchers
        # This adds a new TailWatcher: TailWatcher(path: "tail.txt1", inode: inode_0)
        d.instance.refresh_watchers

        # The old TailWathcer is detached here since `rotate_wait` is `4s`.
        sleep 3

        # Append to the new current log file.
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f| f.puts "file2 log2"}
      end

      inode_0 = tail_watchers[0].ino
      inode_1 = tail_watchers[1].ino
      record_values = d.events.collect { |event| event[2]["message"] }.sort
      position_entries = []
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.pos", "r") do |f|
        f.readlines(chomp: true).each do |line|
          values = line.split("\t")
          position_entries.append([values[0], values[1], values[2].to_i(16)])
        end
      end

      assert_equal(
        {
          record_values: ["file1 log1", "file1 log2", "file2 log1", "file2 log2"],
          tail_watcher_paths: ["#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail.txt1"],
          tail_watcher_inodes: [inode_0, inode_1, inode_0],
          tail_watcher_io_handler_opened_statuses: [false, false, false],
          position_entries: [
            # The recorded path is old, but it is no problem. The path is not used when using follow_inodes.
            ["#{@tmp_dir}/tail.txt", "0000000000000016", inode_0],
            ["#{@tmp_dir}/tail.txt", "0000000000000016", inode_1],
          ],
        },
        {
          record_values: record_values,
          tail_watcher_paths: tail_watchers.collect { |tw| tw.path },
          tail_watcher_inodes: tail_watchers.collect { |tw| tw.ino },
          tail_watcher_io_handler_opened_statuses: tail_watchers.collect { |tw| tw.instance_variable_get(:@io_handler)&.opened? || false },
          position_entries: position_entries
        },
      )
    end

    # The scenario where in_tail wrongly detaches TailWatcher.
    # This is reported in https://github.com/fluent/fluentd/issues/4190.
    def test_updateTW_after_refreshTW
      config = config_element(
        "ROOT",
        "",
        {
          "path" => "#{@tmp_dir}/tail.txt*",
          "pos_file" => "#{@tmp_dir}/tail.pos",
          "tag" => "t1",
          "format" => "none",
          "read_from_head" => "true",
          "follow_inodes" => "true",
          # In order to detach the old watcher quickly.
          "rotate_wait" => "1s",
          # In order to reproduce the same condition stably, ensure that `refresh_watchers` is not
          # called by a timer.
          "refresh_interval" => "1h",
          # stat_watcher often calls `TailWatcher::on_notify` faster than creating a new log file,
          # so disable it in order to reproduce the same condition stably.
          "enable_stat_watcher" => "false",
        }
      )
      d = create_driver(config, false)

      tail_watchers = []
      stub.proxy(d.instance).setup_watcher do |tw|
        tail_watchers.append(tw)
        tw
      end

      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f| f.puts "file1 log1"}

      d.run(expect_records: 4, timeout: 10) do
        # Rotate (If the timing is bad, `TailWatcher::on_notify` might be called between mv and new-file-creation)
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f| f.puts "file1 log2"}
        FileUtils.move("#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail.txt" + "1")
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f| f.puts "file2 log1"}

        # This reproduces the following situation:
        #     Rotation => refresh_watchers => update_watcher
        # This add a new TailWatcher: TailWatcher(path: "tail.txt", inode: inode_1)
        #     This overwrites `@tails["tail.txt"]`
        d.instance.refresh_watchers

        # `watch_timer` calls `TailWatcher::on_notify`, and then `update_watcher` trys to update the TailWatcher:
        #     TailWatcher(path: "tail.txt", inode: inode_0) => TailWatcher(path: "tail.txt", inode: inode_1)
        # However, it is already added in `refresh_watcher`, so `update_watcher` doesn't create the new TailWatcher.
        # The old TailWathcer is detached here since `rotate_wait` is just `1s`.
        sleep 3

        # This adds a new TailWatcher: TailWatcher(path: "tail.txt1", inode: inode_0)
        d.instance.refresh_watchers

        # Append to the new current log file.
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f| f.puts "file2 log2"}
      end

      inode_0 = tail_watchers[0].ino
      inode_1 = tail_watchers[1].ino
      record_values = d.events.collect { |event| event[2]["message"] }.sort
      position_entries = []
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.pos", "r") do |f|
        f.readlines(chomp: true).each do |line|
          values = line.split("\t")
          position_entries.append([values[0], values[1], values[2].to_i(16)])
        end
      end

      assert_equal(
        {
          record_values: ["file1 log1", "file1 log2", "file2 log1", "file2 log2"],
          tail_watcher_paths: ["#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail.txt1"],
          tail_watcher_inodes: [inode_0, inode_1, inode_0],
          tail_watcher_io_handler_opened_statuses: [false, false, false],
          position_entries: [
            # The recorded path is old, but it is no problem. The path is not used when using follow_inodes.
            ["#{@tmp_dir}/tail.txt", "0000000000000016", inode_0],
            ["#{@tmp_dir}/tail.txt", "0000000000000016", inode_1],
          ],
        },
        {
          record_values: record_values,
          tail_watcher_paths: tail_watchers.collect { |tw| tw.path },
          tail_watcher_inodes: tail_watchers.collect { |tw| tw.ino },
          tail_watcher_io_handler_opened_statuses: tail_watchers.collect { |tw| tw.instance_variable_get(:@io_handler)&.opened? || false },
          position_entries: position_entries
        },
      )
    end

    def test_path_resurrection
      config = config_element(
        "ROOT",
        "",
        {
          "path" => "#{@tmp_dir}/tail.txt*",
          "pos_file" => "#{@tmp_dir}/tail.pos",
          "tag" => "t1",
          "format" => "none",
          "read_from_head" => "true",
          "follow_inodes" => "true",
          # In order to reproduce the same condition stably, ensure that `refresh_watchers` is not
          # called by a timer.
          "refresh_interval" => "1h",
          # https://github.com/fluent/fluentd/pull/4237#issuecomment-1633358632
          # Because of this problem, log duplication can occur during `rotate_wait`.
          # Need to set `rotate_wait 0` for a workaround.
          "rotate_wait" => "0s",
        }
      )
      d = create_driver(config, false)

      tail_watchers = []
      stub.proxy(d.instance).setup_watcher do |tw|
        tail_watchers.append(tw)
        tw
      end

      Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f| f.puts "file1 log1"}

      d.run(expect_records: 5, timeout: 10) do
        # Rotate
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f| f.puts "file1 log2"}
        FileUtils.move("#{@tmp_dir}/tail.txt", "#{@tmp_dir}/tail.txt" + "1")
        # TailWatcher(path: "tail.txt", inode: inode_0) detects `tail.txt` disappeared.
        #     Call `update_watcher` to stop and discard self.
        # If not discarding, then it will be a orphan and cause leak and log duplication.
        #
        # This reproduces the case where the notify to TailWatcher comes before the new file for the path
        # is created during rotation.
        # (stat_watcher notifies faster than a new file is created)
        # Overall, this is a rotation operation, but from the TailWatcher, it appears as if the file
        # was resurrected once it disappeared.
        sleep 2 # On Windows and macOS, StatWatcher doesn't work, so need enough interval for TimeTrigger.
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "wb") {|f| f.puts "file2 log1"}

        # Add new TailWatchers
        #     tail.txt: TailWatcher(path: "tail.txt", inode: inode_1)
        #     tail.txt: TailWatcher(path: "tail.txt1", inode: inode_0)
        # NOTE: If not discarding the first TailWatcher on notify, this makes it a orphan because
        # this overwrites the `@tails[tail.txt]` by adding TailWatcher(path: "tail.txt", inode: inode_1)
        d.instance.refresh_watchers

        # This does nothing.
        # NOTE: If not discarding the first TailWatcher on notify, this add
        #     tail.txt1: TailWatcher(path: "tail.txt1", inode: inode_0)
        # because the previous refresh_watcher overwrites `@tails[tail.txt]` and the inode_0 is lost.
        # This would cause log duplication.
        d.instance.refresh_watchers

        # Append to the old file
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt1", "ab") {|f| f.puts "file1 log3"}

        # Append to the new current log file.
        Fluent::FileWrapper.open("#{@tmp_dir}/tail.txt", "ab") {|f| f.puts "file2 log2"}
      end

      inode_0 = Fluent::FileWrapper.stat("#{@tmp_dir}/tail.txt1").ino
      inode_1 = Fluent::FileWrapper.stat("#{@tmp_dir}/tail.txt").ino
      record_values = d.events.collect { |event| event[2]["message"] }.sort
      position_entries = []
      Fluent::FileWrapper.open("#{@tmp_dir}/tail.pos", "r") do |f|
        f.readlines(chomp: true).each do |line|
          values = line.split("\t")
          position_entries.append([values[0], values[1], values[2].to_i(16)])
        end
      end

      assert_equal(
        {
          record_values: ["file1 log1", "file1 log2", "file1 log3", "file2 log1", "file2 log2"],
          tail_watcher_set: Set[
            {
              path: "#{@tmp_dir}/tail.txt",
              inode: inode_0,
              io_handler_opened_status: false,
            },
            {
              path: "#{@tmp_dir}/tail.txt",
              inode: inode_1,
              io_handler_opened_status: false,
            },
            {
              path: "#{@tmp_dir}/tail.txt1",
              inode: inode_0,
              io_handler_opened_status: false,
            },
          ],
          position_entries: [
            ["#{@tmp_dir}/tail.txt", "0000000000000021", inode_0],
            ["#{@tmp_dir}/tail.txt", "0000000000000016", inode_1],
          ],
        },
        {
          record_values: record_values,
          tail_watcher_set: Set.new(tail_watchers.collect { |tw|
            {
              path: tw.path,
              inode: tw.ino,
              io_handler_opened_status: tw.instance_variable_get(:@io_handler)&.opened? || false,
            }
          }),
          position_entries: position_entries,
        },
      )
    end
  end
end