Module: MemoryProfiler::TopN

Included in:
StatHash
Defined in:
lib/memory_profiler/top_n.rb

Instance Method Summary collapse

Instance Method Details

#top_n(max = 10) ⇒ Object

Efficient mechanism for finding top_n entries in a list optional block can specify custom element and weight



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# File 'lib/memory_profiler/top_n.rb', line 5

def top_n(max = 10)

  sorted =
    if block_given?
      self.map { |row|
        yield(row)
      }
    else
      self.dup
    end

  sorted.compact!
  sorted.sort!

  found = []

  last = sorted[0]
  count = 0
  lowest_count = 0

  sorted << nil

  sorted.each do |row|

    current_item, current_count = row

    unless current_item == last
      if count > lowest_count
        found << {data: last, count: count}
      end

      if found.length > max
        found.sort!{|x,y| x[:count] <=> y[:count] }
        found.delete_at(0)
        lowest_count = found[0][:count]
      end

      count = 0
      last = current_item
    end

    count += (current_count || 1) unless row.nil?
  end

  found
    .sort!{|x,y| x[:count] <=> y[:count] }
    .reverse
end