scanlog

#!/usr/bin/env ruby
require 'beaver'
require 'uri'
require 'csv'
require 'optparse'
require 'pry'

class FilterForLongActions
  # time_limit: look at actions taking longer than this in seconds
  # logs: search the logs files matching this glob string
  def initialize(time_limit:, logs:)
    @time_limit = time_limit
    beaver = Beaver.new(logs = logs)
    @requests = beaver.parse.requests
    puts "Beavering on #{logs}. #{@requests.count} requests found exceeding #{time_limit} seconds"
  end

  # Summarize the requests, highest time first
  def summary
    requests.select { |r| r.ms > s2ms(@time_limit) }.sort{ |a, b| b.ms <=> a.ms }
  end

  def display
    summary.each do |hit|
      printf "%04is: %6s %-34s %s (@ %s)\n", ms2s(hit.ms), hit.method, *components(hit.path), hit.time.strftime('%D %T')
      # [r.method, r.action, r.path, r.controller, r.status, r.time, r.ms, r.params]
    end
  end

  def to_csv(file_descriptor = $stdout)
    CSV(file_descriptor) do |csv|
      csv << %w[action_time method endpoint arguments date_time status params]
      summary.each do |hit|
        csv << [ms2s(hit.ms), hit.method, *components(hit.path), hit.time, hit.status, hit.method, hit.params]
      end
    end
  end

  private

  attr_reader :requests, :time_limit

  def s2ms(seconds)
    seconds * 1000
  end

  def ms2s(milliseconds)
    (milliseconds/1000).round
  end

  def components(path)
    pretty_path = URI.decode(path)
    endpoint = pretty_path[/^.*\?/]
    return [pretty_path, ""] if endpoint.nil?
    return [endpoint[0..-2], pretty_path[/\?.*$/]]
  end

  def add_commas(num)
    num.to_s.reverse.gsub(/...(?=.)/,'\&,').reverse
  end

  def ms2s(milliseconds)
    (milliseconds/1000).round
  end
end

options = {}
command_line = OptionParser.new do |opts|
  opts.on('-t', '--threshold=SECONDS', Float, 'threshold for deciding if an action has taken too long') do |threshold|
    options[:threshold] = threshold
  end

  opts.on('-c', '--csv[=STRING]', String, 'generate a CSV file (to $stderr if no file specified)') do |csv|
    options[:csv] = csv
  end

  opts.on('-n', '--nodisplay', 'do not display results') do |no_display|
    options[:no_display] = no_display
  end

  opts.on('-h', '--help', 'display this usage message') do
    puts opts
    exit 1
  end
end

args = command_line.parse!
options[:threshold] = 10 if options[:threshold].nil?

if args.count == 0 || args.count > 1
  $stderr.puts "? invalid number of arguments"
  $stderr.puts command_line.help
  exit 1
end

long_actions = FilterForLongActions.new(time_limit: options[:threshold], logs: args.first)
long_actions.display unless options[:no_display]

exit 0 unless options.key?(:csv)

csv_file = $stderr
csv_file = File.open(options[:csv], "wb") unless options[:csv].nil?
long_actions.to_csv(csv_file)