Contents

require "fluent/input"

module Fluent
  class SystemdInput < Input
    class PosWriter
      def initialize(pos_file)
        @path = pos_file
        @lock = Mutex.new
        @cursor = nil
        @written_cursor = nil
        setup
      end

      attr_reader :cursor, :path

      def start
        return unless @path
        @running = true
        @thread = Thread.new(&method(:work))
      end

      def shutdown
        return unless @path
        @running = false
        @thread.join
        write_pos
      end

      def update(c)
        return unless @path
        @lock.synchronize { @cursor = c }
      end

      private

      def setup
        return unless @path && File.exist?(@path)
        @cursor = IO.read(@path).chomp
      end

      def work
        while @running
          write_pos
          sleep 1
        end
      end

      def write_pos
        @lock.synchronize do
          if @written_cursor != @cursor
            file = File.open(@path, "w+")
            file.print @cursor
            file.close
            @written_cursor = @cursor
          end
        end
      end
    end
  end
end

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
fluent-plugin-systemd-0.0.6	lib/fluent/plugin/systemd/pos_writer.rb