cola/gitcmd.py

   1 import os
   2
   3 from cola import git
   4
   5
   6 # Provides access to a global GitCola instance
   7 _instance = None
   8 def instance():
   9     """Return the GitCola singleton"""
  10     global _instance
  11     if _instance:
  12         return _instance
  13     _instance = GitCola()
  14     return _instance
  15
  16
  17 class GitCola(git.Git):
  18     """
  19     Subclass git.Git to provide custom behaviors.
  20
  21     GitPython throws exceptions by default.
  22     We suppress exceptions in favor of return values.
  23
  24     """
  25     def __init__(self):
  26         git.Git.__init__(self)
  27         self.load_worktree(os.getcwd())
  28
  29     def load_worktree(self, path):
  30         self._git_dir = path
  31         self._worktree = None
  32         self.worktree()
  33
  34     def worktree(self):
  35         if self._worktree:
  36             return self._worktree
  37         self.git_dir()
  38         if self._git_dir:
  39             curdir = self._git_dir
  40         else:
  41             curdir = os.getcwd()
  42
  43         if self._is_git_dir(os.path.join(curdir, '.git')):
  44             return curdir
  45
  46         # Handle bare repositories
  47         if (len(os.path.basename(curdir)) > 4
  48                 and curdir.endswith('.git')):
  49             return curdir
  50         if 'GIT_WORK_TREE' in os.environ:
  51             self._worktree = os.getenv('GIT_WORK_TREE')
  52         if not self._worktree or not os.path.isdir(self._worktree):
  53             if self._git_dir:
  54                 gitparent = os.path.join(os.path.abspath(self._git_dir), '..')
  55                 self._worktree = os.path.abspath(gitparent)
  56                 self.set_cwd(self._worktree)
  57         return self._worktree
  58
  59     def is_valid(self):
  60         return self._git_dir and self._is_git_dir(self._git_dir)
  61
  62     def git_dir(self):
  63         if self.is_valid():
  64             return self._git_dir
  65         if 'GIT_DIR' in os.environ:
  66             self._git_dir = os.getenv('GIT_DIR')
  67         if self._git_dir:
  68             curpath = os.path.abspath(self._git_dir)
  69         else:
  70             curpath = os.path.abspath(os.getcwd())
  71         # Search for a .git directory
  72         while curpath:
  73             if self._is_git_dir(curpath):
  74                 self._git_dir = curpath
  75                 break
  76             gitpath = os.path.join(curpath, '.git')
  77             if self._is_git_dir(gitpath):
  78                 self._git_dir = gitpath
  79                 break
  80             curpath, dummy = os.path.split(curpath)
  81             if not dummy:
  82                 break
  83         return self._git_dir
  84
  85     def _is_git_dir(self, d):
  86         """From git's setup.c:is_git_directory()."""
  87         if (os.path.isdir(d)
  88                 and os.path.isdir(os.path.join(d, 'objects'))
  89                 and os.path.isdir(os.path.join(d, 'refs'))):
  90             headref = os.path.join(d, 'HEAD')
  91             return (os.path.isfile(headref)
  92                     or (os.path.islink(headref)
  93                     and os.readlink(headref).startswith('refs')))
  94         return False