Source code for duplicity.patchdir

# -*- Mode:Python; indent-tabs-mode:nil; tab-width:4; encoding:utf-8 -*-
#
# Copyright 2002 Ben Escoto <ben@emerose.org>
# Copyright 2007 Kenneth Loafman <kenneth@loafman.com>
#
# This file is part of duplicity.
#
# Duplicity is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 2 of the License, or (at your
# option) any later version.
#
# Duplicity is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with duplicity; if not, write to the Free Software Foundation,
# Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

from builtins import map
from builtins import next
from builtins import object
from builtins import range

import re
import sys
import tempfile

from duplicity import errors
from duplicity import diffdir
from duplicity import config
from duplicity import librsync
from duplicity import log
from duplicity import selection
from duplicity import tarfile
from duplicity import tempdir
from duplicity import util
from duplicity.lazy import *  # pylint: disable=unused-wildcard-import,redefined-builtin
from duplicity.path import *  # pylint: disable=unused-wildcard-import,redefined-builtin

u"""Functions for patching of directories"""


[docs]class PatchDirException(Exception): pass
[docs]def Patch(base_path, difftar_fileobj): u"""Patch given base_path and file object containing delta""" diff_tarfile = tarfile.TarFile(u"arbitrary", u"r", difftar_fileobj) patch_diff_tarfile(base_path, diff_tarfile) assert not difftar_fileobj.close()
[docs]def Patch_from_iter(base_path, fileobj_iter, restrict_index=()): u"""Patch given base_path and iterator of delta file objects""" diff_tarfile = TarFile_FromFileobjs(fileobj_iter) patch_diff_tarfile(base_path, diff_tarfile, restrict_index)
[docs]def patch_diff_tarfile(base_path, diff_tarfile, restrict_index=()): u"""Patch given Path object using delta tarfile (as in tarfile.TarFile) If restrict_index is set, ignore any deltas in diff_tarfile that don't start with restrict_index. """ if base_path.exists(): path_iter = selection.Select(base_path).set_iter() else: path_iter = empty_iter() # probably untarring full backup diff_path_iter = difftar2path_iter(diff_tarfile) if restrict_index: diff_path_iter = filter_path_iter(diff_path_iter, restrict_index) collated = diffdir.collate2iters(path_iter, diff_path_iter) ITR = IterTreeReducer(PathPatcher, [base_path]) for basis_path, diff_ropath in collated: if basis_path: log.Info(_(u"Patching %s") % (util.fsdecode(basis_path.get_relative_path())), log.InfoCode.patch_file_patching, util.escape(basis_path.get_relative_path())) ITR(basis_path.index, basis_path, diff_ropath) else: log.Info(_(u"Patching %s") % (util.fsdecode(diff_ropath.get_relative_path())), log.InfoCode.patch_file_patching, util.escape(diff_ropath.get_relative_path())) ITR(diff_ropath.index, basis_path, diff_ropath) ITR.Finish() base_path.setdata()
[docs]def empty_iter(): if 0: yield 1 # this never happens, but fools into generator treatment
[docs]def filter_path_iter(path_iter, index): u"""Rewrite path elements of path_iter so they start with index Discard any that doesn't start with index, and remove the index prefix from the rest. """ assert isinstance(index, tuple) and index, index l = len(index) for path in path_iter: if path.index[:l] == index: path.index = path.index[l:] yield path
[docs]def difftar2path_iter(diff_tarfile): u"""Turn file-like difftarobj into iterator of ROPaths""" tar_iter = iter(diff_tarfile) multivol_fileobj = None # The next tar_info is stored in this one element list so # Multivol_Filelike below can update it. Any StopIterations will # be passed upwards. try: tarinfo_list = [next(tar_iter)] except StopIteration: return while 1: # This section relevant when a multivol diff is last in tar if not tarinfo_list[0]: return if multivol_fileobj and not multivol_fileobj.at_end: multivol_fileobj.close() # aborting in middle of multivol continue index, difftype, multivol = get_index_from_tarinfo(tarinfo_list[0]) ropath = ROPath(index) ropath.init_from_tarinfo(tarinfo_list[0]) ropath.difftype = difftype if difftype == u"deleted": ropath.type = None elif ropath.isreg(): if multivol: multivol_fileobj = Multivol_Filelike(diff_tarfile, tar_iter, tarinfo_list, index) ropath.setfileobj(multivol_fileobj) yield ropath continue # Multivol_Filelike will reset tarinfo_list else: ropath.setfileobj(diff_tarfile.extractfile(tarinfo_list[0])) yield ropath try: tarinfo_list[0] = next(tar_iter) except StopIteration: return
[docs]def get_index_from_tarinfo(tarinfo): u"""Return (index, difftype, multivol) pair from tarinfo object""" for prefix in [u"snapshot/", u"diff/", u"deleted/", u"multivol_diff/", u"multivol_snapshot/"]: tiname = util.get_tarinfo_name(tarinfo) if sys.version_info.major == 2 and isinstance(prefix, unicode): prefix = prefix.encode() if tiname.startswith(prefix): name = tiname[len(prefix):] # strip prefix if prefix.startswith(u"multivol"): if prefix == u"multivol_diff/": difftype = u"diff" else: difftype = u"snapshot" multivol = 1 name, num_subs = \ re.subn(u"(?s)^multivol_(diff|snapshot)/?(.*)/[0-9]+$", u"\\2", tiname) if num_subs != 1: raise PatchDirException(u"Unrecognized diff entry %s" % tiname) else: difftype = prefix[:-1] # strip trailing / name = tiname[len(prefix):] if name.endswith(r"/"): name = name[:-1] # strip trailing /'s multivol = 0 break else: raise PatchDirException(u"Unrecognized diff entry %s" % tiname) if name == r"." or name == r"": index = () else: if sys.version_info.major >= 3: index = tuple(util.fsencode(name).split(b"/")) else: index = tuple(name.split(b"/")) if b'..' in index: raise PatchDirException(u"Tar entry %s contains '..'. Security " u"violation" % util.fsdecode(tiname)) return index, difftype, multivol
[docs]class Multivol_Filelike(object): u"""Emulate a file like object from multivols Maintains a buffer about the size of a volume. When it is read() to the end, pull in more volumes as desired. """
[docs] def __init__(self, tf, tar_iter, tarinfo_list, index): u"""Initializer. tf is TarFile obj, tarinfo is first tarinfo""" self.tf, self.tar_iter = tf, tar_iter self.tarinfo_list = tarinfo_list # must store as list for write access self.index = index self.buffer = b"" self.at_end = False
[docs] def read(self, length=-1): u"""Read length bytes from file""" if length < 0: while self.addtobuffer(): pass real_len = len(self.buffer) else: while len(self.buffer) < length: if not self.addtobuffer(): break real_len = min(len(self.buffer), length) result = self.buffer[:real_len] self.buffer = self.buffer[real_len:] return result
[docs] def addtobuffer(self): u"""Add next chunk to buffer""" if self.at_end: return False index, difftype, multivol = get_index_from_tarinfo(self.tarinfo_list[0]) if not multivol or index != self.index: # we've moved on # the following communicates next tarinfo to difftar2path_iter self.at_end = True return False fp = self.tf.extractfile(self.tarinfo_list[0]) self.buffer += fp.read() fp.close() try: self.tarinfo_list[0] = next(self.tar_iter) except StopIteration: self.tarinfo_list[0] = None self.at_end = True return False return True
[docs] def close(self): u"""If not at end, read remaining data""" if not self.at_end: while True: self.buffer = b"" if not self.addtobuffer(): break self.at_end = True
[docs]class PathPatcher(ITRBranch): u"""Used by DirPatch, process the given basis and diff"""
[docs] def __init__(self, base_path): u"""Set base_path, Path of root of tree""" self.dir_basis_path = None self.base_path = base_path self.dir_diff_ropath = None
[docs] def start_process(self, index, basis_path, diff_ropath): u"""Start processing when diff_ropath is a directory""" if not (diff_ropath and diff_ropath.isdir()): assert index == (), util.uindex(index) # should only happen for first elem self.fast_process(index, basis_path, diff_ropath) return if not basis_path: basis_path = self.base_path.new_index(index) assert not basis_path.exists() basis_path.mkdir() # Need place for later files to go into elif not basis_path.isdir(): basis_path.delete() basis_path.mkdir() self.dir_basis_path = basis_path self.dir_diff_ropath = diff_ropath
[docs] def end_process(self): u"""Copy directory permissions when leaving tree""" if self.dir_diff_ropath: self.dir_diff_ropath.copy_attribs(self.dir_basis_path)
[docs] def can_fast_process(self, index, basis_path, diff_ropath): # pylint: disable=unused-argument u"""No need to recurse if diff_ropath isn't a directory""" return not (diff_ropath and diff_ropath.isdir())
[docs] def fast_process(self, index, basis_path, diff_ropath): u"""For use when neither is a directory""" if not diff_ropath: return # no change elif not basis_path: if diff_ropath.difftype == u"deleted": pass # already deleted else: # just copy snapshot over diff_ropath.copy(self.base_path.new_index(index)) elif diff_ropath.difftype == u"deleted": if basis_path.isdir(): basis_path.deltree() else: basis_path.delete() elif not basis_path.isreg() or (basis_path.isreg() and diff_ropath.difftype == u"snapshot"): if basis_path.isdir(): basis_path.deltree() else: basis_path.delete() diff_ropath.copy(basis_path) else: assert diff_ropath.difftype == u"diff", diff_ropath.difftype basis_path.patch_with_attribs(diff_ropath)
[docs]class TarFile_FromFileobjs(object): u"""Like a tarfile.TarFile iterator, but read from multiple fileobjs"""
[docs] def __init__(self, fileobj_iter): u"""Make new tarinfo iterator fileobj_iter should be an iterator of file objects opened for reading. They will be closed at end of reading. """ self.fileobj_iter = fileobj_iter self.tarfile, self.tar_iter = None, None self.current_fp = None
def __iter__(self): # pylint: disable=non-iterator-returned return self
[docs] def set_tarfile(self): u"""Set tarfile from next file object, or raise StopIteration""" if self.current_fp: assert not self.current_fp.close() while True: x = next(self.fileobj_iter) if isinstance(x, errors.BadVolumeException): # continue with the next volume continue else: self.current_fp = x break self.tarfile = util.make_tarfile(u"r", self.current_fp) self.tar_iter = iter(self.tarfile)
def __next__(self): if not self.tarfile: try: self.set_tarfile() except StopIteration: return try: return next(self.tar_iter) except StopIteration: assert not self.tarfile.close() self.set_tarfile() return next(self.tar_iter)
[docs] def extractfile(self, tarinfo): u"""Return data associated with given tarinfo""" return self.tarfile.extractfile(tarinfo)
[docs]def collate_iters(iter_list): u"""Collate iterators by index Input is a list of n iterators each of which must iterate elements with an index attribute. The elements must come out in increasing order, and the index should be a tuple itself. The output is an iterator which yields tuples where all elements in the tuple have the same index, and the tuple has n elements in it. If any iterator lacks an element with that index, the tuple will have None in that spot. """ # overflow[i] means that iter_list[i] has been exhausted # elems[i] is None means that it is time to replenish it. iter_num = len(iter_list) if iter_num == 2: return diffdir.collate2iters(iter_list[0], iter_list[1]) overflow = [None] * iter_num elems = overflow[:] def setrorps(overflow, elems): u"""Set the overflow and rorps list""" for i in range(iter_num): if not overflow[i] and elems[i] is None: try: elems[i] = next(iter_list[i]) except StopIteration: overflow[i] = 1 elems[i] = None def getleastindex(elems): u"""Return the first index in elems, assuming elems isn't empty""" return min([elem.index for elem in [x for x in elems if x]]) def yield_tuples(iter_num, overflow, elems): while 1: setrorps(overflow, elems) if None not in overflow: break index = getleastindex(elems) yieldval = [] for i in range(iter_num): if elems[i] and elems[i].index == index: yieldval.append(elems[i]) elems[i] = None else: yieldval.append(None) yield tuple(yieldval) return yield_tuples(iter_num, overflow, elems)
[docs]class IndexedTuple(object): u"""Like a tuple, but has .index (used previously by collate_iters)"""
[docs] def __init__(self, index, sequence): self.index = index self.data = tuple(sequence)
def __len__(self): return len(self.data) def __getitem__(self, key): u"""This only works for numerical keys (easier this way)""" return self.data[key] def __lt__(self, other): return self.__cmp__(other) == -1 def __le__(self, other): return self.__cmp__(other) != 1 def __ne__(self, other): return not self.__eq__(other) def __gt__(self, other): return self.__cmp__(other) == 1 def __ge__(self, other): return self.__cmp__(other) != -1 def __cmp__(self, other): assert isinstance(other, IndexedTuple) if self.index < other.index: return -1 elif self.index == other.index: return 0 else: return 1 def __eq__(self, other): if isinstance(other, IndexedTuple): return self.index == other.index and self.data == other.data elif isinstance(other, tuple): return self.data == other else: return False def __str__(self): return u"(%s).%s" % (u", ".join(map(str, self.data)), self.index)
[docs]def normalize_ps(patch_sequence): u"""Given an sequence of ROPath deltas, remove blank and unnecessary The sequence is assumed to be in patch order (later patches apply to earlier ones). A patch is unnecessary if a later one doesn't require it (for instance, any patches before a "delete" are unnecessary). """ result_list = [] i = len(patch_sequence) - 1 while i >= 0: delta = patch_sequence[i] if delta is not None: # skip blank entries result_list.insert(0, delta) if delta.difftype != u"diff": break i -= 1 return result_list
[docs]def patch_seq2ropath(patch_seq): u"""Apply the patches in patch_seq, return single ropath""" first = patch_seq[0] assert first.difftype != u"diff", u"First patch in sequence " \ u"%s was a diff" % patch_seq if not first.isreg(): # No need to bother with data if not regular file assert len(patch_seq) == 1, u"Patch sequence isn't regular, but " \ u"has %d entries" % len(patch_seq) return first.get_ropath() current_file = first.open(u"rb") for delta_ropath in patch_seq[1:]: assert delta_ropath.difftype == u"diff", delta_ropath.difftype try: cur_file.fileno() except: u""" librsync insists on a real file object, which we create manually by using the duplicity.tempdir to tell us where. See https://bugs.launchpad.net/duplicity/+bug/670891 for discussion of os.tmpfile() vs tempfile.TemporaryFile() w.r.t. Windows / Posix, which is worked around in librsync.PatchedFile() now. """ tempfp = tempfile.TemporaryFile(dir=tempdir.default().dir()) util.copyfileobj(current_file, tempfp) assert not current_file.close() tempfp.seek(0) current_file = tempfp current_file = librsync.PatchedFile(current_file, delta_ropath.open(u"rb")) result = patch_seq[-1].get_ropath() result.setfileobj(current_file) return result
[docs]def integrate_patch_iters(iter_list): u"""Combine a list of iterators of ropath patches The iter_list should be sorted in patch order, and the elements in each iter_list need to be orderd by index. The output will be an iterator of the final ROPaths in index order. """ collated = collate_iters(iter_list) for patch_seq in collated: normalized = normalize_ps(patch_seq) try: final_ropath = patch_seq2ropath(normalized) if final_ropath.exists(): # otherwise final patch was delete yield final_ropath except Exception as e: filename = normalized[-1].get_ropath().get_relative_path() log.Warn(_(u"Error '%s' patching %s") % (util.uexc(e), util.fsdecode(filename)), log.WarningCode.cannot_process, util.escape(filename))
[docs]def tarfiles2rop_iter(tarfile_list, restrict_index=()): u"""Integrate tarfiles of diffs into single ROPath iter Then filter out all the diffs in that index which don't start with the restrict_index. """ diff_iters = [difftar2path_iter(x) for x in tarfile_list] if restrict_index: # Apply filter before integration diff_iters = [filter_path_iter(x, restrict_index) for x in diff_iters] return integrate_patch_iters(diff_iters)
[docs]def Write_ROPaths(base_path, rop_iter): u"""Write out ropaths in rop_iter starting at base_path Returns 1 if something was actually written, 0 otherwise. """ ITR = IterTreeReducer(ROPath_IterWriter, [base_path]) return_val = 0 for ropath in rop_iter: return_val = 1 ITR(ropath.index, ropath) ITR.Finish() base_path.setdata() return return_val
[docs]class ROPath_IterWriter(ITRBranch): u"""Used in Write_ROPaths above We need to use an ITR because we have to update the permissions/times of directories after we write the files in them. """
[docs] def __init__(self, base_path): u"""Set base_path, Path of root of tree""" self.base_path = base_path self.dir_diff_ropath = None self.dir_new_path = None
[docs] def start_process(self, index, ropath): u"""Write ropath. Only handles the directory case""" if not ropath.isdir(): # Base may not be a directory, but rest should assert ropath.index == (), ropath.index new_path = self.base_path.new_index(index) if ropath.exists(): if new_path.exists(): new_path.deltree() ropath.copy(new_path) self.dir_new_path = self.base_path.new_index(index) if self.dir_new_path.exists() and not config.force: # base may exist, but nothing else assert index == (), index else: self.dir_new_path.mkdir() self.dir_diff_ropath = ropath
[docs] def end_process(self): u"""Update information of a directory when leaving it""" if self.dir_diff_ropath: self.dir_diff_ropath.copy_attribs(self.dir_new_path)
[docs] def can_fast_process(self, index, ropath): # pylint: disable=unused-argument u"""Can fast process (no recursion) if ropath isn't a directory""" log.Info(_(u"Writing %s of type %s") % (util.fsdecode(ropath.get_relative_path()), ropath.type), log.InfoCode.patch_file_writing, u"%s %s" % (util.escape(ropath.get_relative_path()), ropath.type)) return not ropath.isdir()
[docs] def fast_process(self, index, ropath): u"""Write non-directory ropath to destination""" if ropath.exists(): ropath.copy(self.base_path.new_index(index))