[PATCH v2 1/8] Add new git-cc-cmd helper to contrib

From: Felipe Contreras <felipe.contreras@gmail.com>
Date: Apr 19, 2013, 05:14 UTC
Message-ID: <1366348458-7706-2-git-send-email-felipe.contreras@gmail.com>
In-Reply-To: <1366348458-7706-1-git-send-email-felipe.contreras@gmail.com>

The code finds the changes of a commit, runs 'git blame' for each chunk to see which other commits are relevant, and then reports the author and signers.

Finally, it calculates what percentage of the total relevant commits each person was involved in, and show only the ones that pass the threshold.

For example:

  % git cc-cmd 0001-remote-hg-trivial-cleanups.patch
  Felipe Contreras <felipe.contreras@gmail.com> (author: 100%)
  Jeff King <peff@peff.net> (signer: 83%)
  Max Horn <max@quendi.de> (signer: 16%)
  Junio C Hamano <gitster@pobox.com> (signer: 16%)

Thus it can be used for 'git send-email' as a cc-cmd.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
---
 contrib/cc-cmd/git-cc-cmd | 140 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 140 insertions(+)
 create mode 100755 contrib/cc-cmd/git-cc-cmd

diff --git a/contrib/cc-cmd/git-cc-cmd b/contrib/cc-cmd/git-cc-cmd
new file mode 100755
index 0000000..c7ecf79
--- /dev/null
+++ b/contrib/cc-cmd/git-cc-cmd
@@ -0,0 +1,140 @@
+#!/usr/bin/env ruby
+
+$since = '3-years-ago'
+$min_percent = 5
+
+class Commit
+
+  attr_reader :id
+  attr_accessor :roles
+
+  def initialize(id)
+    @id = id
+    @roles = []
+  end
+
+  def self.parse(data)
+    id = author = msg = nil
+    roles = {}
+    data.each_line do |line|
+      if not msg
+        case line
+        when /^commit (.+)$/
+          id = $1
+        when /^author ([^<>]+) <(\S+)>$/
+          author = $1, $2
+          roles[author] = 'author'
+        when /^$/
+          msg = true
+        end
+      else
+        if line =~ /^(Signed-off|Reviewed|Acked)-by: ([^<>]+) <(\S+?)>$/
+          person = $2, $3
+          roles[person] = 'signer' if person != author
+        end
+      end
+    end
+    roles = roles.map do |person, role|
+      address = "%s <%s>" % person
+      [person, role]
+    end
+    [id, roles]
+  end
+
+end
+
+class Commits
+
+  attr_reader :items
+
+  def initialize()
+    @items = {}
+  end
+
+  def size
+    @items.size
+  end
+
+  def import
+    return if @items.empty?
+    format = [ 'commit %H', 'author %an <%ae>', '', '%B' ].join('%n')
+    File.popen(['git', 'show', '-z', '-s', '--format=format:' + format] + @items.keys) do |p|
+      p.each("\0") do |data|
+        next if data == "\0" # bug in git show?
+        id, roles = Commit.parse(data)
+        commit = @items[id]
+        commit.roles = roles
+      end
+    end
+  end
+
+  def each_person_role
+    commit_roles = @items.values.map { |commit| commit.roles }.flatten(1)
+    commit_roles.group_by { |person, role| person }.each do |person, commit_roles|
+      commit_roles.group_by { |person, role| role }.each do |role, commit_roles|
+        yield person, role, commit_roles.size
+      end
+    end
+  end
+
+  def get_blame(source, start, offset, from)
+    return unless source
+    File.popen(['git', 'blame', '--incremental', '-C',
+               '-L', '%u,+%u' % [start, offset],
+               '--since', $since, from + '^',
+               '--', source]) do |p|
+      p.each do |line|
+        if line =~ /^(\h{40})/
+          id = $1
+          @items[id] = Commit.new(id)
+        end
+      end
+    end
+  end
+
+  def from_patch(file)
+    source = nil
+    from = nil
+    File.open(file) do |f|
+      f.each do |line|
+        case line
+        when /^From (\h+) (.+)$/
+          from = $1
+        when /^---\s+(\S+)/
+          source = $1 != '/dev/null' ? $1[2..-1] : nil
+        when /^@@\s-(\d+),(\d+)/
+          get_blame(source, $1, $2, from)
+        end
+      end
+    end
+    import
+  end
+
+end
+
+exit 1 if ARGV.size != 1
+
+commits = Commits.new()
+commits.from_patch(ARGV[0])
+
+# hash of hashes
+persons = Hash.new { |hash, key| hash[key] = {} }
+
+commits.each_person_role do |person, role, count|
+  persons[person][role] = count
+end
+
+persons.each do |person, roles|
+  roles = roles.map do |role, count|
+    percent = count.to_f * 100 / commits.size
+    next if percent < $min_percent
+    "%s: %u%%" % [role, percent]
+  end.compact
+  next if roles.empty?
+
+  name, email = person
+  # must quote chars?
+  name = '"%s"' % name if name =~ /[^\w \-]/i
+  person = name ? "%s <%s>" % [name, email] : email
+  puts "%s (%s)" % [person, roles.join(', ')]
+end

-- 
1.8.2.1.790.g4588561