lib/bup/drecurse.py

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