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):
  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             try:
  59                 OsFile(name).fchdir()
  60             except OSError, e:
  61                 add_error('%s: %s' % (prepend, e))
  62             else:
  63                 for i in _recursive_dirlist(prepend=prepend+name, xdev=xdev,
  64                                             bup_dir=bup_dir):
  65                     yield i
  66                 os.chdir('..')
  67         yield (prepend + name, pst)
  68
  69
  70 def recursive_dirlist(paths, xdev, bup_dir=None):
  71     startdir = OsFile('.')
  72     try:
  73         assert(type(paths) != type(''))
  74         for path in paths:
  75             try:
  76                 pst = os.lstat(path)
  77                 if stat.S_ISLNK(pst.st_mode):
  78                     yield (path, pst)
  79                     continue
  80             except OSError, e:
  81                 add_error('recursive_dirlist: %s' % e)
  82                 continue
  83             try:
  84                 pfile = OsFile(path)
  85             except OSError, e:
  86                 add_error(e)
  87                 continue
  88             pst = pfile.stat()
  89             if xdev:
  90                 xdev = pst.st_dev
  91             else:
  92                 xdev = None
  93             if stat.S_ISDIR(pst.st_mode):
  94                 pfile.fchdir()
  95                 prepend = os.path.join(path, '')
  96                 for i in _recursive_dirlist(prepend=prepend, xdev=xdev,
  97                                             bup_dir=bup_dir):
  98                     yield i
  99                 startdir.fchdir()
 100             else:
 101                 prepend = path
 102             yield (prepend,pst)
 103     except:
 104         try:
 105             startdir.fchdir()
 106         except:
 107             pass
 108         raise