```ruby
module Typhoeus
  class Hydra

    # This module handles the request throttling
    #
    # @api private
    module Throttleable
      def available_throttled_capacity
        now = Time.now

        @throttle_buffer.capacity.times do
          if (oldest_timestamp = @throttle_buffer.front) && oldest_timestamp < (now - 1)
            @throttle_buffer.pop
          else
            break
          end
        end

        @throttle_buffer.capacity - @throttle_buffer.size
      end

      def add(request)
        @throttle_buffer.push(Time.now) if throttling_enabled?
        super
      end

      def throttling_enabled?
        !!@throttle_buffer
      end
    end
  end
end
```

Optimize for the case that the whole throttle_buffer can be cleared all at once
user
```ruby
module Typhoeus
  class Hydra

    # This module handles the request throttling
    #
    # @api private
    module Throttleable
      def available_throttled_capacity
        now = Time.now

        if (newest_timestamp = @throttle_buffer.back) && newest_timestamp < (now - 1)
          # Optimize for the case that enough time has passed to reset the buffer
          @throttle_buffer.clear
        else
          @throttle_buffer.capacity.times do
            if (oldest_timestamp = @throttle_buffer.front) && oldest_timestamp < (now - 1)
              @throttle_buffer.pop
            else
              break
            end
          end
        end

        @throttle_buffer.capacity - @throttle_buffer.size
      end

      def add(request)
        @throttle_buffer.push(Time.now) if throttling_enabled?
        super
      end

      def throttling_enabled?
        !!@throttle_buffer
      end
    end
  end
end
```
assistant