git map: Add -h, --help option

git_map.py

 #!/usr/bin/env python
 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """
-Provides an augmented `git log --graph` view. In particular, it also annotates
-commits with branches + tags that point to them. Items are colorized as follows:
+Enhances `git log --graph` view with information on commit branches + tags that
+point to them. Items are colorized as follows:
   * Cyan    - Currently checked out branch
   * Green   - Local branch
   * Red     - Remote branches
   * Magenta - Tags
   * White   - Merge Base Markers
   * Blue background - The currently checked out commit
 """
 
 import sys
 
 import subprocess2
 
 from git_common import current_branch, branches, tags, get_config_list, GIT_EXE
-from git_common import get_or_create_merge_base, root
+from git_common import get_or_create_merge_base, root, ROOT, IS_WIN
 
 from third_party import colorama
 
 CYAN = colorama.Fore.CYAN
 GREEN = colorama.Fore.GREEN
 MAGENTA = colorama.Fore.MAGENTA
 RED = colorama.Fore.RED
 WHITE = colorama.Fore.WHITE
 
 BLUEBAK = colorama.Back.BLUE
 
 BRIGHT = colorama.Style.BRIGHT
 RESET = colorama.Fore.RESET + colorama.Back.RESET + colorama.Style.RESET_ALL
 
 # Git emits combined color
 BRIGHT_RED = '\x1b[1;31m'
 
 def main(argv):
+  if '-h' in argv or '--help' in argv:
+    sys.stdout.write(__doc__)
+    return 0
+
   map_extra = get_config_list('depot_tools.map_extra')
   fmt = '%C(red bold)%h%x09%Creset%C(green)%d%Creset %C(yellow)%ad%Creset ~ %s'
   log_proc = subprocess2.Popen(
     [GIT_EXE, 'log', '--graph', '--branches', '--tags', root(),
      '--color=always', '--date=short', ('--pretty=format:' + fmt)
     ] + map_extra + argv,
     stdout=subprocess2.PIPE,
     shell=False)
 
+  # prepare pager
+  less = 'less'
+  if IS_WIN:
+    with open(ROOT + '\\git.bat') as r:
+      for line in r:
+        start = line.find('%~dp0')
+        if start != -1:
+          GIT_DIR = line[start+5:line.find('\cmd')]
+          less = ROOT + '\\' + GIT_DIR + '\\usr\\bin\\less'
+          break
+  less_proc = subprocess2.Popen([less, '-R'], stdin=subprocess2.PIPE)

[iannucci, 2016/07/19 01:07:55]

please make this a separate CL.

That said, this all looks pretty sketchy (parsing the bat file?)

less.exe should be in the PATH if this was invoked via git. It may be better to
set GIT_PAGER in the shell script above.

+
   current = current_branch()
   all_branches = set(branches())
   merge_base_map = {b: get_or_create_merge_base(b) for b in all_branches}
   merge_base_map = {b: v for b, v in merge_base_map.iteritems() if v}
   if current in all_branches:
     all_branches.remove(current)
   all_tags = set(tags())
   try:
     for line in log_proc.stdout.xreadlines():
       if merge_base_map:
@@ skipping 33 matching lines @@
             elif b in all_tags:
               colored_branches.append(MAGENTA+BRIGHT+b+RESET)
             elif b.startswith('tag: '):
               colored_branches.append(MAGENTA+BRIGHT+b[5:]+RESET)
             else:
               colored_branches.append(RED+b)
             branches_str = '(%s) ' % ((GREEN+", ").join(colored_branches)+GREEN)
           line = "%s%s%s" % (line[:start-1], branches_str, line[end+5:])
           if head_marker:
             line = line.replace('*', head_marker, 1)
-      sys.stdout.write(line)
+      less_proc.stdin.write(line)
   except (IOError, KeyboardInterrupt):
     pass
   finally:
+    # wait for less to exit
+    less_proc.stdin.close()
+    less_proc.wait()
     sys.stderr.close()
     sys.stdout.close()
   return 0
 
 
 if __name__ == '__main__':
   try:
     sys.exit(main(sys.argv[1:]))
   except KeyboardInterrupt:
     sys.stderr.write('interrupted\n')
     sys.exit(1)