class TTY::ProgressBar::Meter

Used by {ProgressBar} to measure progress rate per interval by default 1s

@api private

Public Class Methods

new(interval) click to toggle source

Create Meter

@param [Integer] interval

the interval for measurement samples

@api private

# File lib/tty/progressbar/meter.rb, line 16
def initialize(interval)
  @interval = interval || 1 # 1 sec
  start
end

Public Instance Methods

avg_rate()
Alias for: mean_rate
clear() click to toggle source

Reset the meter by clearing out it's metrics

@api public

# File lib/tty/progressbar/meter.rb, line 111
def clear
  start
end
mean_rate() click to toggle source

The mean rate of all the sampled rates

@return [Number]

the mean rate

@api public

# File lib/tty/progressbar/meter.rb, line 98
def mean_rate
  last_at, last_value = @samples.last
  if last_at == @start_time
    0
  else
    last_value / (last_at - @start_time)
  end
end
Also aliased as: avg_rate
prune_samples(at) click to toggle source

Remove samples that are obsolete

@api private

# File lib/tty/progressbar/meter.rb, line 51
def prune_samples(at)
  cutoff = at - @interval
  while @samples.size > 1 && (@samples.first.first < cutoff)
    @samples.shift
  end
end
rate() click to toggle source

The current rate of sampling for a given interval

@return [Number]

the current rate in decimal or 0 if cannot be determined

@api public

# File lib/tty/progressbar/meter.rb, line 75
def rate
  first_at, first_value = @samples.first
  last_at,  last_value  = @samples.last
  if first_at == last_at
    0
  else
    (last_value - first_value) / (last_at - first_at)
  end
end
rates() click to toggle source

Group all rates per interval

@api public

# File lib/tty/progressbar/meter.rb, line 88
def rates
  @rates + [rate]
end
sample(at, value) click to toggle source

Update meter with value

@param [Time] at

the time of the sampling

@param [Integer] value

the current value of progress

@api public

# File lib/tty/progressbar/meter.rb, line 41
def sample(at, value)
  @current += value
  prune_samples(at)
  @samples << [at, @current]
  save_rate(at)
end
save_rate(at) click to toggle source

If we crossed a period boundary since @start_time, save the rate for {#rates}

@api private

# File lib/tty/progressbar/meter.rb, line 62
def save_rate(at)
  period_index = ((at - @start_time) / @interval).floor
  while period_index > @rates.size
    @rates << rate
  end
end
start() click to toggle source

Start sampling timer

@api public

# File lib/tty/progressbar/meter.rb, line 24
def start
  @start_time = Time.now
  @current    = 0
  @samples    = [[@start_time, 0]]
  @rates      = []
  @start_time
end