script/helpers.py

   1 import os
   2 from os import path
   3 import types
   4 from subprocess import Popen, PIPE, check_call
   5
   6 def run_command(args):
   7     # interpret a string as a whitespace-separated list of executable+arguments
   8     if isinstance(args, types.StringTypes):
   9         args = args.split()
  10     t = Popen(args, stdout=PIPE)
  11     stdout = t.communicate()[0]
  12     if t.returncode != 0:
  13         raise OSError("Call %s failed" % args)
  14     return stdout
  15
  16 class GitWrapper(object):
  17     def __init__(self):
  18         self.shallow = False
  19         self.supports_nofetch = True
  20         v = run_command('git --version')
  21         prefix = 'git version '
  22         def error():
  23             sys.stderr.write('Cannot parse "git --version" output, '
  24                              'assuming new version')
  25         if not v.startswith(prefix):
  26             error()
  27             return
  28         v = v[len(prefix):]
  29         try:
  30             v = [int(n) for n in v.split('.')[:3]]
  31         except:
  32             error()
  33             return
  34         if v < [1, 6, 2]:
  35             self.supports_nofetch = False
  36
  37     def submodule_clone(self, name):
  38         if self.shallow:
  39             # Use a depth greater than 1 for shallow clones to reduce the
  40             # chance that required submodule versions are not fetched when
  41             # all branch heads in the corresponding repo have moved ahead.
  42             shallow_args = ['--depth', '100']
  43         else:
  44             shallow_args = []
  45         if self.supports_nofetch:
  46             nofetch_args = ['--no-fetch']
  47         else:
  48             nofetch_args = []
  49         if path.exists(path.join(name, '.git')):
  50             # If the submodule already exists just try to update it
  51             check_call('git submodule sync'.split()+[name])
  52             check_call('git submodule update'.split()+[name])
  53         else:
  54             # Do things manually instead of using "git submodule update --init",
  55             # because git's sucky submodule support has no way of giving
  56             # options to the "git clone" command that would be needed for
  57             # shallow clones.
  58             repo_addr = run_command('git config --get submodule.%s.url' % name)
  59             # old git versions fail to clone over an empty directory
  60             try:
  61                 os.rmdir(name)
  62             except:
  63                 # Don't fail if it already doesn't exist - having other
  64                 # failure cases continue and fail later is OK.
  65                 pass
  66             check_call('git clone'.split() + shallow_args + [repo_addr, name])
  67             check_call('git submodule update'.split() + nofetch_args + [name])
  68
  69     def get_config(self):
  70         output = run_command('git config --null --list')
  71         result = {}
  72         for line in output.split(chr(0)):
  73             if not line:
  74                 continue
  75             name, value = line.split('\n', 1)
  76             result[name] = value
  77         return result
  78
  79     def get_submodules(self):
  80         output = run_command('git ls-files --stage')
  81         result = []
  82         for line in output.splitlines():
  83             mode, sha, stage, path = line.split(None, 3)
  84             if mode != '160000':
  85                 continue
  86             result.append(path)
  87         return result
  88
  89     def foreach_submodule(self, func, recurse=True):
  90         for module in self.get_submodules():
  91             if path.exists(path.join(module, '.git')):
  92                 os.chdir(module)
  93                 func()
  94                 if recurse:
  95                     self.foreach_submodule(func)
  96                 os.chdir('..')
  97
  98     def foreach_module(self, func):
  99         func()
 100         self.foreach_submodule(func)
 101
 102
 103 def parse_configfile(filename):
 104     if not path.exists(filename):
 105         return []
 106     args = []
 107     f = open(filename)
 108     for line in f:
 109         line = line.strip()
 110         if not line or line.startswith('#'):
 111             continue
 112         args.append(line)
 113     f.close()
 114     return args