lib/bup/drecurse.py

   1 import stat, os
   2 from bup.helpers import *
   3 import bup.xstat as xstat
   4
   5 try:
   6     O_LARGEFILE = os.O_LARGEFILE
   7 except AttributeError:
   8     O_LARGEFILE = 0
   9 try:
  10     O_NOFOLLOW = os.O_NOFOLLOW
  11 except AttributeError:
  12     O_NOFOLLOW = 0
  13
  14
  15 # the use of fchdir() and lstat() is for two reasons:
  16 #  - help out the kernel by not making it repeatedly look up the absolute path
  17 #  - avoid race conditions caused by doing listdir() on a changing symlink
  18 class OsFile:
  19     def __init__(self, path):
  20         self.fd = None
  21         self.fd = os.open(path, os.O_RDONLY|O_LARGEFILE|O_NOFOLLOW|os.O_NDELAY)
  22
  23     def __del__(self):
  24         if self.fd:
  25             fd = self.fd
  26             self.fd = None
  27             os.close(fd)
  28
  29     def fchdir(self):
  30         os.fchdir(self.fd)
  31
  32     def stat(self):
  33         return xstat.fstat(self.fd)
  34
  35
  36 _IFMT = stat.S_IFMT(0xffffffff)  # avoid function call in inner loop
  37 def _dirlist():
  38     l = []
  39     for n in os.listdir('.'):
  40         try:
  41             st = xstat.lstat(n)
  42         except OSError as e:
  43             add_error(Exception('%s: %s' % (resolve_parent(n), str(e))))
  44             continue
  45         if (st.st_mode & _IFMT) == stat.S_IFDIR:
  46             n += '/'
  47         l.append((n,st))
  48     l.sort(reverse=True)
  49     return l
  50
  51
  52 def _recursive_dirlist(prepend, xdev, bup_dir=None,
  53                        excluded_paths=None,
  54                        exclude_rxs=None):
  55     for (name,pst) in _dirlist():
  56         path = prepend + name
  57         if excluded_paths:
  58             if os.path.normpath(path) in excluded_paths:
  59                 debug1('Skipping %r: excluded.\n' % path)
  60                 continue
  61         if exclude_rxs and should_rx_exclude_path(path, exclude_rxs):
  62             continue
  63         if name.endswith('/'):
  64             if bup_dir != None:
  65                 if os.path.normpath(path) == bup_dir:
  66                     debug1('Skipping BUP_DIR.\n')
  67                     continue
  68             if xdev != None and pst.st_dev != xdev:
  69                 debug1('Skipping contents of %r: different filesystem.\n' % path)
  70             else:
  71                 try:
  72                     OsFile(name).fchdir()
  73                 except OSError as e:
  74                     add_error('%s: %s' % (prepend, e))
  75                 else:
  76                     for i in _recursive_dirlist(prepend=prepend+name, xdev=xdev,
  77                                                 bup_dir=bup_dir,
  78                                                 excluded_paths=excluded_paths,
  79                                                 exclude_rxs=exclude_rxs):
  80                         yield i
  81                     os.chdir('..')
  82         yield (path, pst)
  83
  84
  85 def recursive_dirlist(paths, xdev, bup_dir=None, excluded_paths=None,
  86                       exclude_rxs=None):
  87     startdir = OsFile('.')
  88     try:
  89         assert(type(paths) != type(''))
  90         for path in paths:
  91             try:
  92                 pst = xstat.lstat(path)
  93                 if stat.S_ISLNK(pst.st_mode):
  94                     yield (path, pst)
  95                     continue
  96             except OSError as e:
  97                 add_error('recursive_dirlist: %s' % e)
  98                 continue
  99             try:
 100                 pfile = OsFile(path)
 101             except OSError as e:
 102                 add_error(e)
 103                 continue
 104             pst = pfile.stat()
 105             if xdev:
 106                 xdev = pst.st_dev
 107             else:
 108                 xdev = None
 109             if stat.S_ISDIR(pst.st_mode):
 110                 pfile.fchdir()
 111                 prepend = os.path.join(path, '')
 112                 for i in _recursive_dirlist(prepend=prepend, xdev=xdev,
 113                                             bup_dir=bup_dir,
 114                                             excluded_paths=excluded_paths,
 115                                             exclude_rxs=exclude_rxs):
 116                     yield i
 117                 startdir.fchdir()
 118             else:
 119                 prepend = path
 120             yield (prepend,pst)
 121     except:
 122         try:
 123             startdir.fchdir()
 124         except:
 125             pass
 126         raise