class ElasticAPM::Util::LruCache

def [](key)
  found = true
  value = @data.delete(key) { found = false }
  if found
    @data[key] = value
  else
    @missing_key_block && @missing_key_block.call(self, key)
  end
end

def []=(key, val)
  @data.delete(key)
  @data[key] = val
  return unless @data.length > @max_size
  @data.delete(@data.first[0])
end

def initialize(max_size = 512, &block)
  @max_size = max_size
  @data = Hash.new(&block)
  @missing_key_block = block
end

def length
  @data.length
end

def to_a
  @data.to_a
end