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Diffstat (limited to 'obnam/obj.py')
| -rw-r--r-- | obnam/obj.py | 521 |
1 files changed, 0 insertions, 521 deletions
diff --git a/obnam/obj.py b/obnam/obj.py deleted file mode 100644 index 5168900c..00000000 --- a/obnam/obj.py +++ /dev/null @@ -1,521 +0,0 @@ -# Copyright (C) 2006, 2007, 2008 Lars Wirzenius <liw@iki.fi> -# -# This program 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. -# -# This program 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 this program; if not, write to the Free Software Foundation, Inc., -# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. - - -"""Backup objects""" - -import logging - -import uuid - -import obnam.cmp -import obnam.varint - - -# Magic cookie at the beginning of every block - -BLOCK_COOKIE = "blockhead\n" - - -# Version of the storage format - -FORMAT_VERSION = "1" - - -# Constants of object kinds - -_object_kinds = {} - -def _define_kind(code, name): - assert code not in _object_kinds - assert name not in _object_kinds.values() - _object_kinds[code] = name - return code - -FILEPART = _define_kind( 1, "FILEPART") -# object kind 2 used to be INODE, but it's been removed -GEN = _define_kind( 3, "GEN") -SIG = _define_kind( 4, "SIG") -HOST = _define_kind( 5, "HOST") -FILECONTENTS = _define_kind( 6, "FILECONTENTS") -FILELIST = _define_kind( 7, "FILELIST") -DELTA = _define_kind( 8, "DELTA") -DELTAPART = _define_kind( 9, "DELTAPART") -DIR = _define_kind(10, "DIR") -FILEGROUP = _define_kind(11, "FILEGROUP") - - -def kind_name(kind): - """Return a textual name for a numeric object kind""" - return _object_kinds.get(kind, "UNKNOWN") - - -def object_id_new(): - """Return a string that is a universally unique ID for an object""" - id = str(uuid.uuid4()) - logging.debug("Creating object id %s" % id) - return id - - -class StorageObject(object): - - """Implement a storage object in memory. - - There should be a sub-class of this class for every kind of storage - object. Sub-class may implement a constructor, but their construct - MUST accept a components= argument and pass it on to the base class - constructor. - - Additionally, sub-classes MUST define the "kind" attribute to refer - to the kind of storage object they are. This is required for - the StorageObjectFactory to work. - - """ - - kind = None - - def __init__(self, components=None, id=None): - assert components is not None or id is not None - if components: - self._components = components - else: - self._components = [] - - if id: - self.set_id(id) - if self.first_varint_by_kind(obnam.cmp.OBJKIND) is None and self.kind: - self.add(obnam.cmp.Component(obnam.cmp.OBJKIND, - obnam.varint.encode(self.kind))) - - def remove(self, kind): - """Remove all components of a given kind.""" - self._components = [c for c in self.get_components() - if c.get_kind() != kind] - - def add(self, c): - """Add a component""" - self._components.append(c) - - def replace(self, c): - """Remove any existing components of this kind, then add this one.""" - self.remove(c.get_kind()) - self.add(c) - - def get_kind(self): - """Return the kind of an object""" - return self.first_varint_by_kind(obnam.cmp.OBJKIND) - - def get_id(self): - """Return the identifier for an object""" - return self.first_string_by_kind(obnam.cmp.OBJID) - - def set_id(self, id): - """Set the identifier for this object.""" - self.replace(obnam.cmp.Component(obnam.cmp.OBJID, id)) - - def get_components(self): - """Return list of all components in an object""" - return self._components - - def find_by_kind(self, wanted_kind): - """Find all components of a desired kind inside this object""" - return [c for c in self.get_components() - if c.get_kind() == wanted_kind] - - def find_strings_by_kind(self, wanted_kind): - """Find all components of a desired kind, return string values""" - return [c.get_string_value() for c in self.find_by_kind(wanted_kind)] - - def find_varints_by_kind(self, wanted_kind): - """Find all components of a desired kind, return varint values""" - return [c.get_varint_value() for c in self.find_by_kind(wanted_kind)] - - def first_by_kind(self, wanted_kind): - """Find first component of a desired kind""" - for c in self.get_components(): - if c.get_kind() == wanted_kind: - return c - return None - - def first_string_by_kind(self, wanted_kind): - """Find string value of first component of a desired kind""" - c = self.first_by_kind(wanted_kind) - if c: - return c.get_string_value() - else: - return None - - def first_varint_by_kind(self, wanted_kind): - """Find string value of first component of a desired kind""" - c = self.first_by_kind(wanted_kind) - if c: - return c.get_varint_value() - else: - return None - - def encode(self): - """Encode an object as a string""" - return "".join(c.encode() for c in self.get_components()) - - -# This function is only used during testing. -def decode(encoded): - """Decode an object from a string""" - parser = obnam.cmp.Parser(encoded) - list = parser.decode_all() - return StorageObject(components=list) - - -class ObjectQueue: - - def __init__(self): - self.clear() - - def add(self, object_id, encoded_object): - """Add an encoded object into an object queue""" - self.queue.append((object_id, encoded_object)) - self.size += len(encoded_object) - - def clear(self): - """Remove all objects from an object queue""" - self.queue = [] - self.size = 0 - - def is_empty(self): - """Is an object queue empty?""" - return self.size == 0 - - def combined_size(self): - """Return the combined size of all objects in an object queue""" - return self.size - - def ids(self): - """Return identifiers for all the objects in the object queue""" - return [x[0] for x in self.queue] - - def as_block(self, blkid): - """Create a block from an object queue""" - logging.debug("Creating block %s" % blkid) - blkid = obnam.cmp.Component(obnam.cmp.BLKID, blkid) - objects = [obnam.cmp.Component(obnam.cmp.OBJECT, x[1]) - for x in self.queue] - return "".join([BLOCK_COOKIE] + - [c.encode() for c in [blkid] + objects]) - - -class BlockWithoutCookie(obnam.ObnamException): - - def __init__(self, block): - self._msg = ("Block does not start with cookie: %s" % - " ".join("%02x" % ord(c) for c in block[:32])) - - -class EmptyBlock(obnam.ObnamException): - - def __init__(self): - self._msg = "Block has no components." - - -def block_decode(block): - """Return list of decoded components in block, or None on error""" - if block.startswith(BLOCK_COOKIE): - parser = obnam.cmp.Parser(block, len(BLOCK_COOKIE)) - list = parser.decode_all() - if not list: - raise EmptyBlock() - return list - else: - raise BlockWithoutCookie(block) - - -class SignatureObject(StorageObject): - - kind = SIG - - def __init__(self, components=None, id=None, sigdata=None): - StorageObject.__init__(self, components=components, id=id) - if sigdata: - c = obnam.cmp.Component(obnam.cmp.SIGDATA, sigdata) - self.add(c) - - -class DeltaObject(StorageObject): - - kind = DELTA - - def __init__(self, components=None, id=None, deltapart_refs=None, - cont_ref=None, delta_ref=None): - StorageObject.__init__(self, components=components, id=id) - if deltapart_refs: - for deltapart_ref in deltapart_refs: - c = obnam.cmp.Component(obnam.cmp.DELTAPARTREF, deltapart_ref) - self.add(c) - if cont_ref: - c = obnam.cmp.Component(obnam.cmp.CONTREF, cont_ref) - self.add(c) - elif delta_ref: - c = obnam.cmp.Component(obnam.cmp.DELTAREF, delta_ref) - self.add(c) - - -class GenerationObject(StorageObject): - - kind = GEN - - def __init__(self, components=None, id=None, filelist_id=None, - dirrefs=None, filegrouprefs=None, start=None, end=None): - StorageObject.__init__(self, components=components, id=id) - if filelist_id: - self.add(obnam.cmp.Component(obnam.cmp.FILELISTREF, filelist_id)) - if dirrefs: - for ref in dirrefs: - self.add(obnam.cmp.Component(obnam.cmp.DIRREF, ref)) - if filegrouprefs: - for ref in filegrouprefs: - self.add(obnam.cmp.Component(obnam.cmp.FILEGROUPREF, ref)) - if start: - self.add(obnam.cmp.Component(obnam.cmp.GENSTART, - obnam.varint.encode(start))) - if end: - self.add(obnam.cmp.Component(obnam.cmp.GENEND, - obnam.varint.encode(end))) - - def get_filelistref(self): - return self.first_string_by_kind(obnam.cmp.FILELISTREF) - - def get_dirrefs(self): - return self.find_strings_by_kind(obnam.cmp.DIRREF) - - def get_filegrouprefs(self): - return self.find_strings_by_kind(obnam.cmp.FILEGROUPREF) - - def get_start_time(self): - return self.first_varint_by_kind(obnam.cmp.GENSTART) - - def get_end_time(self): - return self.first_varint_by_kind(obnam.cmp.GENEND) - - -# This is used only by testing. -def generation_object_decode(gen): - """Decode a generation object into objid, file list ref""" - - o = decode(gen) - return o.get_id(), \ - o.first_string_by_kind(obnam.cmp.FILELISTREF), \ - o.find_strings_by_kind(obnam.cmp.DIRREF), \ - o.find_strings_by_kind(obnam.cmp.FILEGROUPREF), \ - o.first_varint_by_kind(obnam.cmp.GENSTART), \ - o.first_varint_by_kind(obnam.cmp.GENEND) - - -class HostBlockObject(StorageObject): - - kind = HOST - - def __init__(self, components=None, host_id=None, gen_ids=None, - map_block_ids=None, contmap_block_ids=None): - StorageObject.__init__(self, components=components, id=host_id) - - if components is None: - c = obnam.cmp.Component(obnam.cmp.FORMATVERSION, FORMAT_VERSION) - self.add(c) - - if gen_ids: - for gen_id in gen_ids: - c = obnam.cmp.Component(obnam.cmp.GENREF, gen_id) - self.add(c) - - if map_block_ids: - for map_block_id in map_block_ids: - c = obnam.cmp.Component(obnam.cmp.MAPREF, map_block_id) - self.add(c) - - if contmap_block_ids: - for map_block_id in contmap_block_ids: - c = obnam.cmp.Component(obnam.cmp.CONTMAPREF, map_block_id) - self.add(c) - - def get_generation_ids(self): - """Return IDs of all generations for this host.""" - return self.find_strings_by_kind(obnam.cmp.GENREF) - - def get_map_block_ids(self): - """Return IDs of all map blocks for this host.""" - return self.find_strings_by_kind(obnam.cmp.MAPREF) - - def get_contmap_block_ids(self): - """Return IDs of all map blocks for this host.""" - return self.find_strings_by_kind(obnam.cmp.CONTMAPREF) - - def encode(self): - oq = ObjectQueue() - oq.add(self.get_id(), StorageObject.encode(self)) - return oq.as_block(self.get_id()) - - -def create_host_from_block(block): - """Decode a host block into a HostBlockObject""" - - list = block_decode(block) - - host_id = obnam.cmp.first_string_by_kind(list, obnam.cmp.BLKID) - - gen_ids = [] - map_ids = [] - contmap_ids = [] - - objparts = obnam.cmp.find_by_kind(list, obnam.cmp.OBJECT) - for objpart in objparts: - gen_ids += objpart.find_strings_by_kind(obnam.cmp.GENREF) - map_ids += objpart.find_strings_by_kind(obnam.cmp.MAPREF) - contmap_ids += objpart.find_strings_by_kind(obnam.cmp.CONTMAPREF) - - return HostBlockObject(host_id=host_id, gen_ids=gen_ids, - map_block_ids=map_ids, - contmap_block_ids=contmap_ids) - - -class DirObject(StorageObject): - - kind = DIR - - def __init__(self, components=None, id=None, name=None, stat=None, - dirrefs=None, filegrouprefs=None): - StorageObject.__init__(self, components=components, id=id) - if name: - self.add(obnam.cmp.Component(obnam.cmp.FILENAME, name)) - if stat: - self.add(obnam.cmp.create_stat_component(stat)) - if dirrefs: - for ref in dirrefs: - self.add(obnam.cmp.Component(obnam.cmp.DIRREF, ref)) - if filegrouprefs: - for ref in filegrouprefs: - self.add(obnam.cmp.Component(obnam.cmp.FILEGROUPREF, ref)) - - def get_name(self): - return self.first_by_kind(obnam.cmp.FILENAME).get_string_value() - - def get_stat(self): - st = self.first_by_kind(obnam.cmp.STAT) - return obnam.cmp.parse_stat_component(st) - - def get_dirrefs(self): - return [c.get_string_value() - for c in self.find_by_kind(obnam.cmp.DIRREF)] - - def get_filegrouprefs(self): - return [c.get_string_value() - for c in self.find_by_kind(obnam.cmp.FILEGROUPREF)] - - -class FileGroupObject(StorageObject): - - kind = FILEGROUP - - def add_file(self, name, stat, contref, sigref, deltaref): - c = obnam.filelist.create_file_component_from_stat(name, stat, - contref, sigref, - deltaref) - self.add(c) - - def get_files(self): - return self.find_by_kind(obnam.cmp.FILE) - - def get_file(self, name): - for file in self.get_files(): - fname = file.first_string_by_kind(obnam.cmp.FILENAME) - if name == fname: - return file - return None - - def get_string_from_file(self, file, kind): - return file.first_string_by_kind(kind) - - def get_stat_from_file(self, file): - c = file.first_by_kind(obnam.cmp.STAT) - return obnam.cmp.parse_stat_component(c) - - def get_names(self): - return [self.get_string_from_file(x, obnam.cmp.FILENAME) - for x in self.get_files()] - - def get_stat(self, filename): - return self.get_stat_from_file(self.get_file(filename)) - - def get_contref(self, filename): - return self.get_string_from_file(self.get_file(filename), - obnam.cmp.CONTREF) - - def get_sigref(self, filename): - return self.get_string_from_file(self.get_file(filename), - obnam.cmp.SIGREF) - - def get_deltaref(self, filename): - return self.get_string_from_file(self.get_file(filename), - obnam.cmp.DELTAREF) - - -class FileListObject(StorageObject): - - kind = FILELIST - - -class FilePartObject(StorageObject): - - kind = FILEPART - - -class FileContentsObject(StorageObject): - - kind = FILECONTENTS - - -class DeltaPartObject(StorageObject): - - kind = DELTAPART - - -class UnknownStorageObjectKind(obnam.ObnamException): - - def __init__(self, kind): - self._msg = "Unknown storage object kind %s" % kind - - -class StorageObjectFactory: - - """Create the right kind of Object subclass instance. - - Given a parsed component representing an object, figure out the type - of the object and instantiate the right sub-class of Object. - - """ - - def __init__(self): - self._classes = [] - for n, klass in globals().iteritems(): - if (type(klass) is type(StorageObject) and - klass != StorageObject and - issubclass(klass, StorageObject)): - self._classes.append(klass) - - def get_object(self, components): - kind = obnam.cmp.first_varint_by_kind(components, obnam.cmp.OBJKIND) - for klass in self._classes: - if klass.kind == kind: - return klass(components=components) - raise UnknownStorageObjectKind(kind) |