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, e:
  43             add_error(Exception('%s: %s' % (realpath(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, excluded_paths=None):
  53     for (name,pst) in _dirlist():
  54         if name.endswith('/'):
  55             if xdev != None and pst.st_dev != xdev:
  56                 debug1('Skipping %r: different filesystem.\n' % (prepend+name))
  57                 continue
  58             if bup_dir != None:
  59                 if os.path.normpath(prepend+name) == bup_dir:
  60                     debug1('Skipping BUP_DIR.\n')
  61                     continue
  62             if excluded_paths:
  63                 if os.path.normpath(prepend+name) in excluded_paths:
  64                     debug1('Skipping %r: excluded.\n' % (prepend+name))
  65                     continue
  66             try:
  67                 OsFile(name).fchdir()
  68             except OSError, e:
  69                 add_error('%s: %s' % (prepend, e))
  70             else:
  71                 for i in _recursive_dirlist(prepend=prepend+name, xdev=xdev,
  72                                             bup_dir=bup_dir,
  73                                             excluded_paths=excluded_paths):
  74                     yield i
  75                 os.chdir('..')
  76         yield (prepend + name, pst)
  77
  78
  79 def recursive_dirlist(paths, xdev, bup_dir=None, excluded_paths=None):
  80     startdir = OsFile('.')
  81     try:
  82         assert(type(paths) != type(''))
  83         for path in paths:
  84             try:
  85                 pst = xstat.lstat(path)
  86                 if stat.S_ISLNK(pst.st_mode):
  87                     yield (path, pst)
  88                     continue
  89             except OSError, e:
  90                 add_error('recursive_dirlist: %s' % e)
  91                 continue
  92             try:
  93                 pfile = OsFile(path)
  94             except OSError, e:
  95                 add_error(e)
  96                 continue
  97             pst = pfile.stat()
  98             if xdev:
  99                 xdev = pst.st_dev
 100             else:
 101                 xdev = None
 102             if stat.S_ISDIR(pst.st_mode):
 103                 pfile.fchdir()
 104                 prepend = os.path.join(path, '')
 105                 for i in _recursive_dirlist(prepend=prepend, xdev=xdev,
 106                                             bup_dir=bup_dir,
 107                                             excluded_paths=excluded_paths):
 108                     yield i
 109                 startdir.fchdir()
 110             else:
 111                 prepend = path
 112             yield (prepend,pst)
 113     except:
 114         try:
 115             startdir.fchdir()
 116         except:
 117             pass
 118         raise
 119
 120 def parse_excludes(flags):
 121     excluded_paths = []
 122
 123     for flag in flags:
 124         (option, parameter) = flag
 125         if option == '--exclude':
 126             excluded_paths.append(realpath(parameter))
 127
 128         if option == '--exclude-from':
 129             try:
 130                 try:
 131                     f = open(realpath(parameter))
 132                     for exclude_path in f.readlines():
 133                         excluded_paths.append(realpath(exclude_path.strip()))
 134                 except Error, e:
 135                     log("warning: couldn't read %s\n" % parameter)
 136             finally:
 137                 f.close()
 138
 139     return excluded_paths
 140