Class: DynamoAutoscale::LocalDataPoll

Inherits:
Poller
  • Object
show all
Includes:
Logger
Defined in:
lib/dynamo-autoscale/local_data_poll.rb

Instance Attribute Summary

Attributes inherited from Poller

#filters, #tables

Instance Method Summary collapse

Methods included from Logger

included, logger, #logger, logger=

Methods inherited from Poller

#dispatch, #run

Constructor Details

#initialize(*args) ⇒ LocalDataPoll

Returns a new instance of LocalDataPoll.



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# File 'lib/dynamo-autoscale/local_data_poll.rb', line 5

def initialize *args
  super(*args)
  @cache = Hash.new { |h, k| h[k] = {} }
end

Instance Method Details

#poll(tables, &block) ⇒ Object 



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# File 'lib/dynamo-autoscale/local_data_poll.rb', line 10

def poll tables, &block
  if tables.nil?
    tables = ["*"]
  end

  tables.each do |table_name|
    unless @cache[table_name].empty?
      @cache[table_name].each do |day, table_day_data|
        block.call(table_name, table_day_data)
      end
    else
      file = "#{table_name}.json"

      Dir[File.join(DynamoAutoscale.data_dir, '*')].each do |day_path|
        Dir[File.join(day_path, file)].each do |table_path|
          data = JSON.parse(File.read(table_path)).symbolize_keys

          if data[:consumed_writes].nil? or data[:consumed_reads].nil?
            logger.warn "[ld_poller] Lacking data for table #{table_name}. Skipping."
            next
          end

          # All this monstrosity below is doing is parsing the time keys in
          # the nested hash from strings into Time objects. Hash mapping
          # semantics are weird, hence why this looks ridiculous.
          data = Hash[data.map do |key, ts|
            [
              key,
              Hash[ts.map do |t, d|
                [Time.parse(t), d]
              end],
            ]
          end]

          @cache[table_name][day_path] = data

          block.call(table_name, data)
        end
      end
    end
  end
end