git-who

#!/usr/bin/env ruby

require 'parseopt'

$since = '5-years-ago'
$threshold = 5
$roles = false

$base_dir = %x[git rev-parse --show-toplevel].chomp

ROLE_MAP = {
  'signed-off-by' => :signer,
  'acked-by' => :acker,
  'reviewed-by' => :reviewer,
  'helped-by' => :helper,
  'mentored-by' => :mentor,
  'suggested-by' => :advisor,
  'cc' => :observer,
  'noticed-by' => :sentry,
  'tested-by' => :tester,
  'improved-by' => :enhancer,
  'thanks-to' => :helper,
  'based-on-patch-by' => :patcher,
  'based-on-a-patch-by' => :patcher,
  'contributions-by' => :contributor,
  'co-authored-by' => :coauthor,
  'requested-by' => :solicitor,
  'original-patch-by ' => :patcher,
}
ROLE_REGEX = /^([^ \t\n\[\]\(\):]+): ([^<>]+) <(\S+?)>$/

opts = ParseOpt.new
opts.usage = 'git related [options] <files | rev-list options>'

opts.on('t', 'threshold', 'Minimum percentage threshold of participation') do |v|
  $threshold = v.to_i
end

opts.on('s', 'since', 'How far back to search') do |v|
  $since = v
end

opts.on('r', 'roles', 'Display specific roles') do |v|
  $roles = v
end

opts.parse

class Person

  attr_reader :roles

  def initialize(name, email)
    @name = name
    @email = email
    @roles = Hash.new(0)
  end

  def add_role(role)
    @roles[role] += 1
  end

  def weight
    @roles.values.sum
  end

  def <=>(b)
    weight <=> b.weight
  end

  def to_s
    '%s <%s>' % [@name, @email]
  end

  def self.get(name, email)
    $persons[email.downcase] ||= Person.new(name, email)
  end

end

$persons = {}
$commits = 0

log_args = [ '--no-merges', '--find-copies-harder', '--format=%aN%n%aE%n%b%x00', '--since', $since ]
IO.popen(%w[git log] + log_args + ARGV) do |pipe|
  pipe.each("\0\n") do |commit|
    name, email, body = commit.scrub.split("\n", 3)
    author = Person.get(name, email)
    author.add_role(:author)
    $commits += 1
    next unless $roles
    trailer = body.split("\n\n").last
    trailer.scan(ROLE_REGEX) do
      person = Person.get($2, $3)
      role = ROLE_MAP[$1.downcase]
      next if role == :signer and person == author
      person.add_role(role)
    end
  end
end

$persons.values.sort.reverse.each do |person|
  percent = 100 * person.weight.to_f / $commits
  next if percent < $threshold

  unless $roles
    summary = '%i%%' % percent.round
  else
    roles = person.roles.sort_by(&:last).reverse.map do |role, role_count|
      role_percent = (100 * role_count.to_f / $commits).round
      next if role_percent == 0
      '%s: %i%%' % [role, role_percent]
    end
    summary = roles.compact.join(', ')
  end

  format = STDOUT.isatty ? "%s \e[1;34m(%s)\e[0m" : '%s (%s)'
  puts format % [person, summary]
end