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 try:
   9     O_NOFOLLOW = os.O_NOFOLLOW
  10 except AttributeError:
  11     O_NOFOLLOW = 0
  12
  13
  14 # the use of fchdir() and lstat() is for two reasons:
  15 #  - help out the kernel by not making it repeatedly look up the absolute path
  16 #  - avoid race conditions caused by doing listdir() on a changing symlink
  17 class OsFile:
  18     def __init__(self, path):
  19         self.fd = None
  20         self.fd = os.open(path, os.O_RDONLY|O_LARGEFILE|O_NOFOLLOW|os.O_NDELAY)
  21
  22     def __del__(self):
  23         if self.fd:
  24             fd = self.fd
  25             self.fd = None
  26             os.close(fd)
  27
  28     def fchdir(self):
  29         os.fchdir(self.fd)
  30
  31     def stat(self):
  32         return os.fstat(self.fd)
  33
  34
  35 _IFMT = stat.S_IFMT(0xffffffff)  # avoid function call in inner loop
  36 def _dirlist():
  37     l = []
  38     for n in os.listdir('.'):
  39         try:
  40             st = os.lstat(n)
  41         except OSError, e:
  42             add_error(Exception('%s: %s' % (realpath(n), str(e))))
  43             continue
  44         if (st.st_mode & _IFMT) == stat.S_IFDIR:
  45             n += '/'
  46         l.append((n,st))
  47     l.sort(reverse=True)
  48     return l
  49
  50
  51 def _recursive_dirlist(prepend, xdev, bup_dir=None, excluded_paths=None):
  52     for (name,pst) in _dirlist():
  53         if name.endswith('/'):
  54             if xdev != None and pst.st_dev != xdev:
  55                 debug1('Skipping %r: different filesystem.\n' % (prepend+name))
  56                 continue
  57             if bup_dir != None:
  58                 if os.path.normpath(prepend+name) == bup_dir:
  59                     debug1('Skipping BUP_DIR.\n')
  60                     continue
  61             if excluded_paths:
  62                 if os.path.normpath(prepend+name) in excluded_paths:
  63                     debug1('Skipping %r: excluded.\n' % (prepend+name))
  64                     continue
  65             try:
  66                 OsFile(name).fchdir()
  67             except OSError, e:
  68                 add_error('%s: %s' % (prepend, e))
  69             else:
  70                 for i in _recursive_dirlist(prepend=prepend+name, xdev=xdev,
  71                                             bup_dir=bup_dir,
  72                                             excluded_paths=excluded_paths):
  73                     yield i
  74                 os.chdir('..')
  75         yield (prepend + name, pst)
  76
  77
  78 def recursive_dirlist(paths, xdev, bup_dir=None, excluded_paths=None):
  79     startdir = OsFile('.')
  80     try:
  81         assert(type(paths) != type(''))
  82         for path in paths:
  83             try:
  84                 pst = os.lstat(path)
  85                 if stat.S_ISLNK(pst.st_mode):
  86                     yield (path, pst)
  87                     continue
  88             except OSError, e:
  89                 add_error('recursive_dirlist: %s' % e)
  90                 continue
  91             try:
  92                 pfile = OsFile(path)
  93             except OSError, e:
  94                 add_error(e)
  95                 continue
  96             pst = pfile.stat()
  97             if xdev:
  98                 xdev = pst.st_dev
  99             else:
 100                 xdev = None
 101             if stat.S_ISDIR(pst.st_mode):
 102                 pfile.fchdir()
 103                 prepend = os.path.join(path, '')
 104                 for i in _recursive_dirlist(prepend=prepend, xdev=xdev,
 105                                             bup_dir=bup_dir,
 106                                             excluded_paths=excluded_paths):
 107                     yield i
 108                 startdir.fchdir()
 109             else:
 110                 prepend = path
 111             yield (prepend,pst)
 112     except:
 113         try:
 114             startdir.fchdir()
 115         except:
 116             pass
 117         raise
 118
 119 def parse_excludes(flags):
 120     excluded_paths = []
 121
 122     for flag in flags:
 123         (option, parameter) = flag
 124         if option == '--exclude':
 125             excluded_paths.append(realpath(parameter))
 126
 127         if option == '--exclude-from':
 128             try:
 129                 try:
 130                     f = open(realpath(parameter))
 131                     for exclude_path in f.readlines():
 132                         excluded_paths.append(realpath(exclude_path.strip()))
 133                 except Error, e:
 134                     log("warning: couldn't read %s" % parameter)
 135             finally:
 136                 f.close()
 137
 138     return excluded_paths
 139