Re: [PATCH v7] Add new git-related helper to contrib

[Ramkumar Ramachandra <artagnon@gmail.com>]

Let's do one more review.

Felipe Contreras wrote:
> diff --git a/contrib/related/git-related b/contrib/related/git-related
> new file mode 100755
> index 0000000..1b9b1e7
> --- /dev/null
> +++ b/contrib/related/git-related
> @@ -0,0 +1,120 @@
> +#!/usr/bin/env ruby
> +
> +# This script finds people that might be interested in a patch
> +# usage: git related <file>
> +
> +$since = '5-years-ago'
> +$min_percent = 10
> +
> +class Commit
> +
> +  attr_reader :persons

Unless you plan to introduce many more fields (I haven't looked at the
later patches), you might as well implement an #each, like in Commits.

> +  def initialize(id)
> +    @id = id
> +    @persons = []
> +  end
> +
> +  def parse(data)
> +    msg = nil

msg = false, to indicate that it is a boolean.

> +    data.each_line do |line|
> +      if not msg
> +        case line
> +        when /^author ([^<>]+) <(\S+)> (.+)$/
> +          @persons << '%s <%s>' % [$1, $2]

Why capture the third group when $3 is unused?

> +        when /^$/
> +          msg = true
> +        end
> +      else
> +        if line =~ /^(Signed-off|Reviewed|Acked)-by: ([^<>]+) <(\S+?)>$/
> +          @persons << '%s <%s>' % [$2, $3]

Why capture the first group when $1 is unused?

> +        end
> +      end
> +    end
> +    @persons.uniq!
> +  end
> +
> +end
> +
> +class Commits
> +
> +  def initialize
> +    @items = {}
> +  end
> +
> +  def size
> +    @items.size
> +  end
> +
> +  def each(&block)
> +    @items.each(&block)
> +  end
> +
> +  def import
> +    return if @items.empty?
> +    File.popen(%w[git cat-file --batch], 'r+') do |p|

Don't you need rb+ to suppress the CRLF nonsense on Windows?

> +      p.write(@items.keys.join("\n"))

As you might have realized, the parentheses are optional everywhere
(except when it is required for disambiguation).  I'm merely pointing
it out here, because this line looks especially ugly.

> +      p.close_write
> +      p.each do |line|
> +        if line =~ /^(\h{40}) commit (\d+)/
> +          id, len = $1, $2

id, len = $1, Integer $2.  And drop the .to_i on the next line.

> +          data = p.read($2.to_i)
> +          @items[id].parse(data)
> +        end
> +      end
> +    end
> +  end
> +
> +  def get_blame(source, start, len, from)
> +    return if len == 0
> +    len ||= 1

I asked you to use 'len =1 if not len' for clarity, but you didn't like it.

> +    File.popen(['git', 'blame', '--incremental', '-C', '-C',
> +               '-L', '%u,+%u' % [start, len],
> +               '--since', $since, from + '^',
> +               '--', source]) do |p|
> +      p.each do |line|
> +        if line =~ /^\h{40}/
> +          id = $&
> +          @items[id] = Commit.new(id)
> +        end
> +      end
> +    end
> +  end
> +
> +  def from_patch(file)
> +    from = source = nil
> +    File.open(file) do |f|
> +      f.each do |line|

File.readlines(file).each do |line|.

> +        case line
> +        when /^From (\h+) (.+)$/
> +          from = $1

Useless capture.

> +        when /^---\s+(\S+)/
> +          source = $1 != '/dev/null' ? $1[2..-1] : nil
> +        when /^@@ -(\d+)(?:,(\d+))?/
> +          get_blame(source, $1, $2, from) if source and from

Useless capture.  When is len ($2) going to be nil?

> +        end
> +      end
> +    end
> +  end
> +
> +end
> +
> +exit 1 if ARGV.size != 1
> +
> +commits = Commits.new
> +commits.from_patch(ARGV[0])
> +commits.import
> +
> +count_per_person = Hash.new(0)
> +
> +commits.each do |id, commit|

commits.each do |_, commit|, since you're not using id.

> +  commit.persons.each do |person|
> +    count_per_person[person] += 1
> +  end
> +end
> +
> +count_per_person.each do |person, count|
> +  percent = count.to_f * 100 / commits.size

I prefer 'Float count' over count.to_f, but that's just a matter of taste.

> +  next if percent < $min_percent
> +  puts person
> +end
> --
> 1.8.3.rc3.312.g47657de