Class: RRDQuery

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(filename) ⇒ RRDQuery

Returns a new instance of RRDQuery.



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# File 'lib/rrd_query.rb', line 6

def initialize(filename)
  @filename = filename
end

Instance Attribute Details

#filename ⇒ Object (readonly)

Returns the value of attribute filename.



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# File 'lib/rrd_query.rb', line 4

def filename
  @filename
end

Instance Method Details

#_rrd ⇒ Object 



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# File 'lib/rrd_query.rb', line 14

def _rrd
  raise("Unable to open RRD, because it doesn't exist: #{@filename}") unless File.exist?(@filename)
  @rrd ||= RRD::Base.new(@filename)
end

#latest_value(datasource) ⇒ Object 



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# File 'lib/rrd_query.rb', line 10

def latest_value(datasource)
  _rrd.info["ds[#{datasource}].last_ds"].to_f
end