lib/bup/drecurse.py

   1 import stat, os
   2 from bup.helpers import *
   3
   4 try:
   5     O_LARGEFILE = os.O_LARGEFILE
   6 except AttributeError:
   7     O_LARGEFILE = 0
   8
   9
  10 # the use of fchdir() and lstat() is for two reasons:
  11 #  - help out the kernel by not making it repeatedly look up the absolute path
  12 #  - avoid race conditions caused by doing listdir() on a changing symlink
  13 class OsFile:
  14     def __init__(self, path):
  15         self.fd = None
  16         self.fd = os.open(path,
  17                           os.O_RDONLY|O_LARGEFILE|os.O_NOFOLLOW|os.O_NDELAY)
  18
  19     def __del__(self):
  20         if self.fd:
  21             fd = self.fd
  22             self.fd = None
  23             os.close(fd)
  24
  25     def fchdir(self):
  26         os.fchdir(self.fd)
  27
  28     def stat(self):
  29         return os.fstat(self.fd)
  30
  31
  32 _IFMT = stat.S_IFMT(0xffffffff)  # avoid function call in inner loop
  33 def _dirlist():
  34     l = []
  35     for n in os.listdir('.'):
  36         try:
  37             st = os.lstat(n)
  38         except OSError, e:
  39             add_error(Exception('%s: %s' % (realpath(n), str(e))))
  40             continue
  41         if (st.st_mode & _IFMT) == stat.S_IFDIR:
  42             n += '/'
  43         l.append((n,st))
  44     l.sort(reverse=True)
  45     return l
  46
  47
  48 def _recursive_dirlist(prepend, xdev, bup_dir=None, excluded_paths=None):
  49     for (name,pst) in _dirlist():
  50         if name.endswith('/'):
  51             if xdev != None and pst.st_dev != xdev:
  52                 log('Skipping %r: different filesystem.\n' % (prepend+name))
  53                 continue
  54             if bup_dir != None:
  55                 if os.path.normpath(prepend+name) == bup_dir:
  56                     log('Skipping BUP_DIR.\n')
  57                     continue
  58             if excluded_paths:
  59                 if os.path.normpath(prepend+name) in excluded_paths:
  60                     log('Skipping %r: excluded.\n' % (prepend+name))
  61                     continue
  62             try:
  63                 OsFile(name).fchdir()
  64             except OSError, e:
  65                 add_error('%s: %s' % (prepend, e))
  66             else:
  67                 for i in _recursive_dirlist(prepend=prepend+name, xdev=xdev,
  68                                             bup_dir=bup_dir,
  69                                             excluded_paths=excluded_paths):
  70                     yield i
  71                 os.chdir('..')
  72         yield (prepend + name, pst)
  73
  74
  75 def recursive_dirlist(paths, xdev, bup_dir=None, excluded_paths=None):
  76     startdir = OsFile('.')
  77     try:
  78         assert(type(paths) != type(''))
  79         for path in paths:
  80             try:
  81                 pst = os.lstat(path)
  82                 if stat.S_ISLNK(pst.st_mode):
  83                     yield (path, pst)
  84                     continue
  85             except OSError, e:
  86                 add_error('recursive_dirlist: %s' % e)
  87                 continue
  88             try:
  89                 pfile = OsFile(path)
  90             except OSError, e:
  91                 add_error(e)
  92                 continue
  93             pst = pfile.stat()
  94             if xdev:
  95                 xdev = pst.st_dev
  96             else:
  97                 xdev = None
  98             if stat.S_ISDIR(pst.st_mode):
  99                 pfile.fchdir()
 100                 prepend = os.path.join(path, '')
 101                 for i in _recursive_dirlist(prepend=prepend, xdev=xdev,
 102                                             bup_dir=bup_dir,
 103                                             excluded_paths=excluded_paths):
 104                     yield i
 105                 startdir.fchdir()
 106             else:
 107                 prepend = path
 108             yield (prepend,pst)
 109     except:
 110         try:
 111             startdir.fchdir()
 112         except:
 113             pass
 114         raise