module StreamCount

Collects IO stats from stdin and prints the stats to stderr. Original stdin is output to stdout.

rubocop:disable all

Constants

BUFFER_SIZE
TICK_DURATION
VERSION

Public Instance Methods

number_with_delimiter(number, delimiter = ',') click to toggle source

Thanks ActiveSupport::NumberHelper

# File lib/stream_count.rb, line 51
def number_with_delimiter(number, delimiter = ',')
  number.to_s.gsub(/(\d)(?=(\d\d\d)+(?!\d))/, "\\1#{delimiter}")
end

output(bytes:, lines:) click to toggle source

output formatted stats to stderr. Using throttle will limit how often we print to stderr to 5/second.

# File lib/stream_count.rb, line 30
def output(bytes:, lines:)
  msg = "\e[1G\e[2K%s seconds | %s bytes [ %s kb/sec ] | %s lines [ %s lines/sec ]"
  duration = Time.now.to_f - @start_time
  if duration > 0
    $stderr.print(msg % [number_with_delimiter(duration.to_i),
                         number_with_delimiter(bytes),
                         number_with_delimiter((bytes / duration / 1024).to_i),
                         number_with_delimiter(lines),
                         number_with_delimiter((lines / duration).to_i)])
  end
end

run(io = ARGF) click to toggle source

Do the work

# File lib/stream_count.rb, line 14
def run(io = ARGF)
  @start_time = Time.now.to_f
  bytes = 0
  lines = 0
  output(bytes: bytes, lines: lines)
  while (data = io.read(BUFFER_SIZE))
    $stdout.write(data)
    bytes += data.size
    lines += data.count($/)
    throttler { output(bytes: bytes, lines: lines) }
  end
  output(bytes: bytes, lines: lines)
end

throttler(threshold: TICK_DURATION) { || ... } click to toggle source

# File lib/stream_count.rb, line 42
def throttler(threshold: TICK_DURATION)
  @last_tick ||= Time.now.to_f
  if Time.now.to_f > (@last_tick + threshold)
    yield
    @last_tick = Time.now.to_f
  end
end