Class: UI

Inherits:
Object
  • Object
show all
Defined in:
lib/ui.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(config) ⇒ UI

Returns a new instance of UI.



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# File 'lib/ui.rb', line 8

def initialize(config)
  @config = config

  @stat_cols    = %w[ calls req/s kB/s hitratio ]
  @stat_col_width = 15
  @key_col_width  = 30
  @avg_period = @config[:avg_period]
  @sort_mode = :reqps
  @sort_order = :desc
  @show_percent = false

  @commands = {
    'B' => "sort by bandwidth",
    'C' => "sort by call number",
    'H' => "sort by hitratio",
    'K' => "sort by key",
    'P' => "display percentages",
    'Q' => "quit",
    'R' => "sort by request rate",
    'T' => "toggle sort order (asc|desc)"
  }

  init_screen
  cbreak
  curs_set(0)

  # set keyboard input timeout - sneaky way to manage refresh rate
  Curses.timeout = @config[:refresh_rate]

  if can_change_color?
    start_color
    init_pair(0, COLOR_WHITE, COLOR_BLACK)
    init_pair(1, COLOR_WHITE, COLOR_BLUE)
    init_pair(2, COLOR_WHITE, COLOR_RED)
  end
end

Instance Attribute Details

#show_percent ⇒ Object

Returns the value of attribute show_percent.



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# File 'lib/ui.rb', line 6

def show_percent
  @show_percent
end

#sort_mode ⇒ Object

Returns the value of attribute sort_mode.



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# File 'lib/ui.rb', line 6

def sort_mode
  @sort_mode
end

#sort_order ⇒ Object

Returns the value of attribute sort_order.



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# File 'lib/ui.rb', line 6

def sort_order
  @sort_order
end

Instance Method Details



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# File 'lib/ui.rb', line 57

def footer
  footer_text = @commands.map { |k,v| "#{k}:#{v}" }.join(' | ')
  setpos(lines - 1, 0)
  attrset(color_pair(2))
  addstr(sprintf "%-#{cols}s", footer_text)
end

#header ⇒ Object 



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# File 'lib/ui.rb', line 45

def header
  # pad stat columns to @stat_col_width
  @stat_cols = @stat_cols.map { |c| sprintf("%#{@stat_col_width}s", c) }

  @url_col_width = cols - @key_col_width - (@stat_cols.length * @stat_col_width)

  attrset(color_pair(1))
  setpos(0,0)
  
  addstr(sprintf "%-#{@key_col_width}s%-#{@url_col_width}s%s", (@config[:host_mode]) ? "hostname" : "request pattern", "last url", @stat_cols.join)
end

#input_handler ⇒ Object 



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# File 'lib/ui.rb', line 173

def input_handler
  # Curses.getch has a bug in 1.8.x causing non-blocking
  # calls to block reimplemented using IO.select
  if RUBY_VERSION =~ /^1.8/
    refresh_secs = @config[:refresh_rate].to_f / 1000

    if IO.select([STDIN], nil, nil, refresh_secs)
      c = getch
      c.chr
    else
      nil
    end
  else
    getch
  end
end

#render_stats(pipe) ⇒ Object 



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# File 'lib/ui.rb', line 64

def render_stats(pipe)
  render_start_t = Time.now.to_f * 1000

  # subtract header + footer lines
  maxlines = lines - 3
  offset = 1

  # construct and render footer stats line
  setpos(lines - 2, 0)
  attrset(color_pair(2))
  header_summary = sprintf "%-24s %-14s %-14s %-14s %-14s",
    "sort mode: #{@sort_mode.to_s} (#{@sort_order.to_s})",
    "| requests: #{pipe.stats[:total_reqs]}",
    "| bytes out: #{pipe.stats[:total_bytes]}",
    "| duration: #{Time.now.to_i - pipe.start_time.to_i}s",
    "| samples: #{@avg_period}"
  addstr(sprintf "%-#{cols}s", header_summary)

  # reset colours for main key display
  attrset(color_pair(0))

  top = []
  totals = {}

  pipe.semaphore.synchronize do
    # we may have seen no packets received on the pipe thread
    return if pipe.start_time.nil?

    time_since_start = Time.now.to_f - pipe.start_time
    elapsed = time_since_start < @avg_period ? time_since_start : @avg_period

    # calculate hits+misses, request rate, bandwidth and hitratio
    pipe.stats[:requests].each do |key,values|
      total_hits = values[:hit].inject(:+)
      total_calls = total_hits + values[:miss].inject(:+)
      total_bytes = values[:bytes].inject(:+)

      pipe.stats[:calls][key] = total_calls
      pipe.stats[:reqps][key] = total_calls.to_f / elapsed
      pipe.stats[:bps][key] = total_bytes.to_f / elapsed
      pipe.stats[:hitratio][key] = total_hits.to_f * 100 / total_calls
    end

    if @sort_mode == :key
      top = pipe.stats[:requests].sort { |a,b| a[0] <=> b[0] }
    else
      top = pipe.stats[@sort_mode].sort { |a,b| a[1] <=> b[1] }
    end

    totals = {
      :calls => pipe.stats[:calls].values.inject(:+),
      :reqps => pipe.stats[:reqps].values.inject(:+),
      :bps => pipe.stats[:bps].values.inject(:+)
    }
  end

  unless @sort_order == :asc
    top.reverse!
  end

  for i in 0..maxlines-1
    if i < top.length
      k = top[i][0]

      # if the key is too wide for the column truncate it and add an ellipsis
      display_key = k.length > @key_col_width ? "#{k[0..@key_col_width-4]}..." : k
      display_url = pipe.stats[:requests][k][:last]
      display_url = display_url.length > @url_col_width ? "#{display_url[0..@url_col_width-4]}..." : display_url

      # render each key
      if @show_percent
        line = sprintf "%-#{@key_col_width}s%-#{@url_col_width}s %14.2f %14.2f %14.2f %14.2f",
                 display_key, display_url,
                 pipe.stats[:calls][k].to_f / totals[:calls] * 100,
                 pipe.stats[:reqps][k] / totals[:reqps] * 100,
                 pipe.stats[:bps][k] / totals[:bps] * 100,
                 pipe.stats[:hitratio][k]
      else
        line = sprintf "%-#{@key_col_width}s%-#{@url_col_width}s %14.d %14.2f %14.2f %14.2f",
                 display_key, display_url,
                 pipe.stats[:calls][k],
                 pipe.stats[:reqps][k],
                 pipe.stats[:bps][k] / 1000,
                 pipe.stats[:hitratio][k]
      end
    else
      # clear remaining lines
      line = " "*cols
    end

    setpos(1 + i, 0)
    addstr(line)
  end

  # Display column totals
  unless @show_percent
    setpos(top.length + 2, 0)
    line = sprintf "%-#{@key_col_width + @url_col_width}s %14.d %14.2f %14.2f",
             "TOTAL", totals[:calls].to_i, totals[:reqps].to_f, totals[:bps].to_f / 1000
    addstr(line)
  end

  # print render time in status bar
  runtime = (Time.now.to_f * 1000) - render_start_t
  attrset(color_pair(2))
  setpos(lines - 2, cols - 24)
  addstr(sprintf "render time: %4.3f (ms)", runtime)
end

#stop ⇒ Object 



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# File 'lib/ui.rb', line 190

def stop
  nocbreak
  close_screen
end