"Fossies" - the Fresh Open Source Software Archive

Member "pysize-0.2/pysize/core/deletion.py" (11 Mar 2007, 3458 Bytes) of package /linux/privat/old/pysize-0.2.tar.gz:

    1 # This program is free software; you can redistribute it and/or modify
    2 # it under the terms of the GNU General Public License as published by
    3 # the Free Software Foundation; either version 2 of the License, or
    4 # (at your option) any later version.
    5 #
    6 # This program is distributed in the hope that it will be useful,
    7 # but WITHOUT ANY WARRANTY; without even the implied warranty of
    8 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    9 # GNU Library General Public License for more details.
   10 #
   11 # You should have received a copy of the GNU General Public License
   12 # along with this program; if not, write to the Free Software
   13 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
   14 #
   15 # See the COPYING file for license information.
   16 #
   17 # Copyright (c) 2006, 2007 Guillaume Chazarain <guichaz@yahoo.fr>
   18 
   19 import os
   20 
   21 from pysize.core.pysize_global_fs_cache import get_dev_ino
   22 
   23 # ['/path/to/file1', '/path/to/file2']
   24 TO_DELETE = []
   25 
   26 # {device: {inode: (size_to_subtract|DELETED)}}
   27 DEV_INO_TO_SUBTRACT = {}
   28 
   29 DELETED = 'deleted'
   30 
   31 def _get_subtracted(path):
   32     dev, ino = get_dev_ino(path)
   33     return DEV_INO_TO_SUBTRACT.setdefault(dev, {}).get(ino, None)
   34 
   35 def _iter_to_the_root(path):
   36     while path not in ('/', ''):
   37         yield get_dev_ino(path), path
   38         path = os.path.dirname(path)
   39 
   40 def get_subtracted(path):
   41     if DEV_INO_TO_SUBTRACT:
   42         for dev_ino, tmp_path in _iter_to_the_root(path):
   43             if _get_subtracted(tmp_path) is DELETED:
   44                 return DELETED
   45         subtracted = _get_subtracted(path)
   46         if subtracted is not None:
   47             return subtracted
   48     return 0
   49 
   50 def _add_hash(path):
   51     from pysize.core import compute_size
   52     size = compute_size.slow(path)
   53     dev, ino = get_dev_ino(path)
   54     DEV_INO_TO_SUBTRACT.setdefault(dev, {})[ino] = DELETED
   55     for (dev, ino), path in _iter_to_the_root(os.path.dirname(path)):
   56         inodes = DEV_INO_TO_SUBTRACT.setdefault(dev, {})
   57         subtract = inodes.get(ino, 0)
   58         subtract += size
   59         inodes[ino] = subtract
   60 
   61 # TODO: Deletion of hard links
   62 def schedule(nodes):
   63     for node in nodes:
   64         for path in node.get_fullpaths():
   65             subtract = get_subtracted(path)
   66             if subtract is not DELETED:
   67                 TO_DELETE.append(path)
   68                 _add_hash(path)
   69     _prune_list()
   70     _rebuild_hash()
   71 
   72 def _prune_list():
   73     """Remove children if we have the parent"""
   74     while True:
   75         for i in xrange(len(TO_DELETE)):
   76             parent = os.path.dirname(TO_DELETE[i])
   77             if get_subtracted(parent) is DELETED:
   78                 del TO_DELETE[i]
   79                 break
   80         else:
   81             break
   82 
   83 def _rebuild_hash():
   84     DEV_INO_TO_SUBTRACT.clear()
   85     for path in TO_DELETE:
   86         _add_hash(path)
   87 
   88 def filter_deleted(paths):
   89     if DEV_INO_TO_SUBTRACT:
   90         def is_not_deleted(path):
   91             return get_subtracted(path) is not DELETED
   92         return filter(is_not_deleted, paths)
   93     return paths
   94 
   95 def get_deleted():
   96     return TO_DELETE[:]
   97 
   98 def restore(path):
   99     from pysize.core import compute_size
  100     TO_DELETE.remove(path)
  101     dev, ino = get_dev_ino(path)
  102     del DEV_INO_TO_SUBTRACT[dev][ino]
  103     size = compute_size.slow(path, account_deletion=False)
  104     for (dev, ino), path in _iter_to_the_root(os.path.dirname(path)):
  105         inodes = DEV_INO_TO_SUBTRACT[dev]
  106         if inodes[ino] == size:
  107             del inodes[ino]
  108         else:
  109             inodes[ino] -= size