Class: LogStash::Filters::Units

Inherits:
Base
  • Object
show all
Defined in:
lib/logstash/filters/units.rb

Overview

The units filter is used for converting specified fields from one unit of measure to another (or many others).

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ Units

Renames the resulting output fields according to a hash. Keys should be the output fields and values should be their desired names, respectively. Unamed fields will persist. Example:

source,ruby

filter { units { fields => [“file_size”] input_unit => “byte” output_units => [“kilobyte”, “megabyte”] rename_labels => { “kilobyte” => “kB” “megabyte” => “mB” } } }



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# File 'lib/logstash/filters/units.rb', line 139

def initialize(*args)
	super(*args)
end

Instance Method Details

#_nested_hash_to_matrix(data, name) ⇒ Object 



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# File 'lib/logstash/filters/units.rb', line 151

def _nested_hash_to_matrix(data, name)
	data.each do |key, val|
		new_key = name + @sep + key.to_s
		if val.is_a?(Hash) and val != {}
			_nested_hash_to_matrix(val, new_key)
		else
			@output.push([new_key, val])
		end
	end
	return @output
end

#filter(event) ⇒ Object 



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# File 'lib/logstash/filters/units.rb', line 224

def filter(event)
	return unless filter?(event)
	begin
		# flag for converting a value in place or expanding it into
		# a hash
		inplace = @output_units.is_a?(String)
		matrix = nested_hash_to_matrix(event.to_hash)		

		# convert matching fields and  remove rows that
		# do not contain leaf nodes that match @fields
		fields = field_handler(@fields)
		del = []
		matrix.each do |row|
			if fields["exact"].include?(row[0])
				if inplace
					row[1] = convert(row[1], @output_units)
				else
					row[1] = convert_to_dict(row[1])
				end
			elsif fields["partial"].include?(row[0][-1])
				if inplace
					row[1] = convert(row[1], @output_units)
				else
					row[1] = convert_to_dict(row[1])
				end
			else
				del.push(row)
			end
		end
		# delete all rows that do not have leaf nodes listed
		# in fields
		for row in del
			matrix.delete(row)
		end
		
		new_hash = matrix_to_nested_hash(matrix)
		if @root_field
			new_hash = {@root_field => new_hash}
		end

		# merge new hash into event's hash
		# assignment of items from new_hash with a prior merge
		# will destroy unmatched branches
		data = event.to_hash().merge(new_hash)
  			data.each do |key, value|
			event[key] = value
		end
		return filter_matched(event)
	rescue StandardError
		event.tag("_unitsparsefailure")
		return event
	rescue Logstash::ShutdownSignal
		event.cancel()
		@logger.debug(e)
	end
end

#register ⇒ Object 



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# File 'lib/logstash/filters/units.rb', line 144

def register()
end