Class: HKeyPerfDataReader::Reader

Inherits:
Object
  • Object
show all
Includes:
Constants
Defined in:
lib/fluent/plugin/hkey_perf_data_reader.rb

Defined Under Namespace

Classes: NullLogger

Constant Summary

Constants included from Constants

Constants::ERROR_MORE_DATA, Constants::ERROR_SUCCESS, Constants::HKEY_PERFORMANCE_DATA, Constants::HKEY_PERFORMANCE_TEXT, Constants::PERF_NO_INSTANCES

Instance Method Summary collapse

Constructor Details

#initialize(object_name_whitelist: [], logger: nil) ⇒ Reader

Returns a new instance of Reader.



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# File 'lib/fluent/plugin/hkey_perf_data_reader.rb', line 65

def initialize(object_name_whitelist: [], logger: nil)
  @raw_data = nil
  @is_little_endian = true
  @binary_parser = nil
  @counter_name_reader = CounterNameTableReader.new
  @object_name_whitelist = Set.new(object_name_whitelist)
  @logger = logger.nil? ? NullLogger.new : logger
end

Instance Method Details

#read ⇒ Object 



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# File 'lib/fluent/plugin/hkey_perf_data_reader.rb', line 74

def read
  @raw_data = RawReader.read(@logger)
  # `littleEndian` flag in PerfDataBlock: https://docs.microsoft.com/en-us/windows/win32/api/winperf/ns-winperf-perf_data_block
  # Although we use this flag value, it will probably never be BigEndian, and we probably don't need to use this value.
  @is_little_endian = @raw_data[8..11].unpack("L")[0] == 1
  if @binary_parser.nil?
    @logger.trace("HKeyPerfData LittlEndian: #{@is_little_endian}")
    @binary_parser = BinaryParser.new(is_little_endian: @is_little_endian)
  end

  header = read_header
  @logger.trace("HKeyPerfData numObjectTypes: #{header.numObjectTypes}")

  unless header.signature == "PERF"
    @logger.error("Could not read HKeyPerfData. The header is invalid.")
    return {}
  end

  perf_objects = {}

  offset = header.headerLength
  header.numObjectTypes.times do
    perf_object, total_byte_length, success = read_perf_object(offset)
    unless success
      if total_byte_length.nil?
        @logger.trace("Can not continue. Stop reading.")
        break
      else
        @logger.trace("Skip this object and continue reading.")
        offset += total_byte_length
        next
      end
    end

    @logger.trace("Duplicate object name: #{perf_object.name}") if perf_objects.key?(perf_object.name)
    perf_objects[perf_object.name] = perf_object
    offset += total_byte_length
  end

  perf_objects
rescue => e
  @logger.error("Could not read HKeyPerfData. Message: #{e.message}")
  {}
end