Class: RRD::Header

Inherits:
Object
  • Object
show all
Defined in:
lib/rrd/header.rb

Constant Summary collapse 

"RRD\0"

8.642135E130

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options) ⇒ Header

Returns a new instance of Header.



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# File 'lib/rrd/header.rb', line 10

def initialize(options)
  @version = options[:version] || "0003"
  @last_update = options[:last_update] # || Time.now
  @step = options[:step] || 10
  @endianess = options[:endianess] || :little
  @alignment = options[:alignment] || 4

  @rra = options[:rra] || []
  @datasources = options[:datasources] || []
end

Instance Attribute Details

#alignment ⇒ Object (readonly)

Returns the value of attribute alignment.



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# File 'lib/rrd/header.rb', line 6

def alignment
  @alignment
end

#datasources ⇒ Object (readonly)

Returns the value of attribute datasources.



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# File 'lib/rrd/header.rb', line 8

def datasources
  @datasources
end

#endianess ⇒ Object (readonly)

Returns the value of attribute endianess.



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# File 'lib/rrd/header.rb', line 6

def endianess
  @endianess
end

#last_update ⇒ Object (readonly)

Returns the value of attribute last_update.



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# File 'lib/rrd/header.rb', line 6

def last_update
  @last_update
end

#rra ⇒ Object (readonly)

Returns the value of attribute rra.



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# File 'lib/rrd/header.rb', line 8

def rra
  @rra
end

#step ⇒ Object (readonly)

Returns the value of attribute step.



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# File 'lib/rrd/header.rb', line 6

def step
  @step
end

#version ⇒ Object (readonly)

Returns the value of attribute version.



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# File 'lib/rrd/header.rb', line 6

def version
  @version
end

Class Method Details

.parse(reader) ⇒ Object 



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# File 'lib/rrd/header.rb', line 26

def self.parse(reader)
  reader.seek(0) # rewind to start

  read_cookie(reader)

  options = {}

  options[:version] = reader.read(5, "a*").first

  read_double_cookie(reader, options)

  datasources_count, rra_count, @step = reader.read(24, "QQQ")

  global_params = reader.read_uniparams(10)

  options[:datasources] = []
  datasources_count.times do |i|
    options[:datasources] << RRD::DataSource.parse(reader)
  end

  options[:rra] = []
  rra_pointer = 0
  rra_count.times do |i|
    rra = RRD::Archive.parse(reader)

    rra.data_pointer = rra_pointer
    rra_pointer += rra.rows * datasources_count * 8

    options[:rra] << rra
  end

  last_update, last_update_msec = reader.read(16, "QQ")

  options[:last_update] = Time.at(last_update.to_f + (last_update_msec.to_f / 1000000))

  datasources_count.times do |i|
    datasource = options[:datasources][i]

    datasource.last_ds = reader.read_string(30, "A*")
    reader.align
    params = reader.read_uniparams(10)
    datasource.unknown_seconds = params[0].to_i
    datasource.last_value = params[1].to_f
  end

  rra_count.times do |rra_index|
    datasources_count.times do |ds_index|
      cdp = RRD::CDP.parse(reader, options[:rra][rra_index])
      options[:rra][rra_index].cdp[ds_index] = cdp
      options[:datasources][ds_index].cdp[rra_index] = cdp
    end
  end

  rra_count.times do |rra_index|
    options[:rra][rra_index].current_row = reader.read(8, "Q").first
  end

  Header.new(options)
end

Instance Method Details

#setup_reader(reader) ⇒ Object 



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# File 'lib/rrd/header.rb', line 21

def setup_reader(reader)
  reader.endianess = endianess
  reader.alignment = alignment
end