scripts/mailmapper

   1 #!/usr/bin/env python3
   2 # SPDX-License-Identifier: GPL-2.0+
   3 #
   4 # Copyright (C) 2014, Masahiro Yamada <yamada.m@jp.panasonic.com>
   5
   6 '''
   7 A tool to create/update the mailmap file
   8
   9 The command 'git shortlog' summarizes git log output in a format suitable
  10 for inclusion in release announcements. Each commit will be grouped by
  11 author and title.
  12
  13 One problem is that the authors' name and/or email address is sometimes
  14 spelled differently. The .mailmap feature can be used to coalesce together
  15 commits by the same persion.
  16 (See 'man git-shortlog' for furthur information of this feature.)
  17
  18 This tool helps to create/update the mailmap file.
  19
  20 It runs 'git shortlog' internally and searches differently spelled author
  21 names which share the same email address. The author name with the most
  22 commits is asuumed to be a canonical real name. If the number of commits
  23 from the cananonical name is equal to or greater than 'MIN_COMMITS',
  24 the entry for the cananical name will be output. ('MIN_COMMITS' is used
  25 here because we do not want to create a fat mailmap by adding every author
  26 with only a few commits.)
  27
  28 If there exists a mailmap file specified by the mailmap.file configuration
  29 options or '.mailmap' at the toplevel of the repository, it is used as
  30 a base file. (The mailmap.file configuration takes precedence over the
  31 '.mailmap' file if both exist.)
  32
  33 The base file and the newly added entries are merged together and sorted
  34 alphabetically (but the comment block is kept untouched), and then printed
  35 to standard output.
  36
  37 Usage
  38 -----
  39
  40   scripts/mailmapper
  41
  42 prints the mailmapping to standard output.
  43
  44   scripts/mailmapper > tmp; mv tmp .mailmap
  45
  46 will be useful for updating '.mailmap' file.
  47 '''
  48
  49 import sys
  50 import os
  51 import subprocess
  52
  53 # The entries only for the canonical names with MIN_COMMITS or more commits.
  54 # This limitation is used so as not to create a too big mailmap file.
  55 MIN_COMMITS = 50
  56
  57 try:
  58     toplevel = subprocess.check_output(['git', 'rev-parse', '--show-toplevel'])
  59 except subprocess.CalledProcessError:
  60     sys.exit('Please run in a git repository.')
  61
  62 # strip '\n'
  63 toplevel = toplevel.rstrip()
  64
  65 # Change the current working directory to the toplevel of the respository
  66 # for our easier life.
  67 os.chdir(toplevel)
  68
  69 # First, create 'auther name' vs 'number of commits' database.
  70 # We assume the name with the most commits as the canonical real name.
  71 shortlog = subprocess.check_output(['git', 'shortlog', '-s', '-n'])
  72
  73 commits_per_name = {}
  74
  75 for line in shortlog.splitlines():
  76     try:
  77         commits, name = line.split(None, 1)
  78     except ValueError:
  79         # ignore lines with an empty author name
  80         pass
  81     commits_per_name[name] = int(commits)
  82
  83 # Next, coalesce the auther names with the same email address
  84 shortlog = subprocess.check_output(['git', 'shortlog', '-s', '-n', '-e'])
  85
  86 mail_vs_name = {}
  87 output = {}
  88
  89 for line in shortlog.splitlines():
  90     # tmp, mail = line.rsplit(None, 1) is not safe
  91     # because weird email addresses might include whitespaces
  92     try:
  93         line = line.decode("utf-8")
  94         tmp, mail = line.split('<')
  95         mail = '<' + mail.rstrip()
  96         _, name = tmp.rstrip().split(None, 1)
  97     except ValueError:
  98         # author name is empty
  99         name = ''
 100     if mail in mail_vs_name:
 101         # another name for the same email address
 102         prev_name = mail_vs_name[mail]
 103         # Take the name with more commits
 104         try:
 105             major_name = sorted([prev_name, name],
 106                                 key=lambda x: commits_per_name[x] if x else 0)[1]
 107         except:
 108             continue
 109         mail_vs_name[mail] = major_name
 110         if commits_per_name[major_name] > MIN_COMMITS:
 111             output[mail] = major_name
 112     else:
 113         mail_vs_name[mail] = name
 114
 115 # [1] If there exists a mailmap file at the location pointed to
 116 #     by the mailmap.file configuration option, update it.
 117 # [2] If the file .mailmap exists at the toplevel of the repository, update it.
 118 # [3] Otherwise, create a new mailmap file.
 119 mailmap_files = []
 120
 121 try:
 122     config_mailmap = subprocess.check_output(['git', 'config', 'mailmap.file'])
 123 except subprocess.CalledProcessError:
 124     config_mailmap = ''
 125
 126 config_mailmap = config_mailmap.rstrip()
 127 if config_mailmap:
 128     mailmap_files.append(config_mailmap)
 129
 130 mailmap_files.append('.mailmap')
 131
 132 infile = None
 133
 134 for map_file in mailmap_files:
 135     try:
 136         infile = open(map_file)
 137     except:
 138         # Failed to open. Try next.
 139         continue
 140     break
 141
 142 comment_block = []
 143 output_lines = []
 144
 145 if infile:
 146     for line in infile:
 147         if line[0] == '#' or line[0] == '\n':
 148             comment_block.append(line)
 149         else:
 150             output_lines.append(line)
 151             break
 152     for line in infile:
 153         output_lines.append(line)
 154     infile.close()
 155
 156 for mail, name in output.items():
 157     output_lines.append(name + ' ' + mail + '\n')
 158
 159 output_lines.sort()
 160
 161 sys.stdout.write(''.join(comment_block + output_lines))